阅读说明：本技术 不透明制品和制备方法 (Opaque article and method of making ) 是由 M·奈尔 M·C·布里克 于 2019-08-30 设计创作，主要内容包括：不透明制品具有(i)具有正面和背面的织物；和(ii)具有基材和干燥不透明层的不透明元件,该基材具有第一相对表面和第二相对表面,该干燥不透明层具有内表面和外表面。设置干燥不透明层,使其内表面与基材的第一相对表面接触。干燥不透明层具有(a)40-90重量%的多孔颗粒,其各自具有连续聚合物相和分散在连续聚合物相内的离散孔。多孔颗粒具有2-50μm的众数粒度和20-70体积%的孔隙率。干燥不透明层还含有(b)10-60重量%的粘合剂材料。将(ii)不透明元件层压到织物的背面,以提供不透明制品。(An opaque article has (i) a fabric having a front side and a back side; and (ii) an opacifying element having a substrate with first and second opposing surfaces and a dry opacifying layer with inner and outer surfaces. The dry opaque layer is positioned such that its inner surface is in contact with the first opposing surface of the substrate. The dry opaque layer has (a)40 to 90 wt% porous particles each having a continuous polymer phase and discrete pores dispersed within the continuous polymer phase. The porous particles have a mode particle size of 2-50 μm and a porosity of 20-70 vol%. The dry opaque layer further comprises (b)10-60 wt% of a binder material. (iii) laminating (ii) an opacifying element to the back of the fabric to provide an opaque article.)

1. An opaque article, comprising:

(i) a fabric having a front side and a back side; and

(ii) an opaque element laminated to a backside of the fabric, the opaque element comprising: a substrate having a first opposing surface and a second opposing surface; and a dry opaque layer having an inner surface and an outer surface, the dry opaque layer being disposed such that its inner surface is in contact with a first opposing surface of the substrate,

the dry opaque layer comprises:

(a) at least 40% and up to and including 90% by weight of porous particles, each porous particle comprising a continuous polymer phase and discrete pores dispersed within the continuous polymer phase, the porous particles having a mode particle size of at least 2 μ ι η and up to and including 50 μ ι η and a porosity of at least 20% and up to and including 70% by volume; and

(b) at least 10% and up to and including 60% by weight of binder material,

(a) the total amount of porous particles and (b) binder material is based on the total weight of the dry opaque layer.

2. The opaque article of claim 1, which has an optical density of at least 3, and the opaque elements have an L of at least 70.

3. The opaque article of claim 1 or 2, wherein the dry opaque layer further comprises at least 0.001 wt%, based on the total dry weight of the dry opaque layer, (c) an opaque colorant capable of absorbing electromagnetic radiation having a wavelength of at least 380 nm and up to and including 800 nm.

4. The opaque article of claim 3, wherein the (c) opacifying colorant is present in an amount of at least 0.001 weight% and up to and including 0.3 weight%, based on the total weight of the dry opaque layer.

5. The opaque article of claim 3 or 4, wherein the (c) opacifying colorant is carbon black, a neutral black pigment or dye other than carbon black, or a combination of two or more such materials.

6. The opaque article of any of claims 1 to 5, wherein an outer surface of the dry opaque layer is laminated to a back side of the fabric.

7. The opaque article of any of claims 1 to 5, wherein a second opposing surface of the substrate is laminated to the back of the fabric.

8. The opaque article of any of claims 1 to 7, further comprising a second dry opaque layer disposed on a second opposing surface of the substrate.

9. The opaque article of any of claims 1 to 8, further comprising an adhesive material disposed between the (i) fabric and the (ii) opaque elements.

10. The opaque article of any of claims 1 to 9, further comprising an adhesive material within the dry opaque layer.

11. The opaque article of claim 9, wherein the adhesive material is a heat seal adhesive or a cold seal adhesive.

12. The opaque article of any of claims 9 to 11, wherein the adhesive material comprises a material selected from the group consisting of: polyamides, polyurethanes, epoxies, polyesters, acrylics, anhydride modified polyolefins, and blends thereof.

13. The opaque article of any of claims 1 to 12, further comprising an antimicrobial agent, a flame retardant, or both an antimicrobial agent and a flame retardant.

14. The opaque article of any of claims 1 to 13, wherein the substrate comprises a polymeric material selected from the group consisting of: polyesters, cellulosic materials, acyclic polyolefins, cyclic olefin polymers, polyamides, ethylene vinyl acetate, polyvinyl chloride, polyvinylidene chloride, and blends thereof.

15. The opaque article of any of claims 1 to 14, wherein the dry opaque layer further comprises one or more (e) additives selected from the group consisting of: dispersants, plasticizers, flame retardants, optical brighteners, thickeners, biocides, tinting colorants, inert inorganic or organic fillers, and combinations of any of these materials.

16. The opaque article of any of claims 1 to 15, wherein the (b) binder material has a glass transition temperature (T) of less than 25 ℃_g)。

17. The opaque article of any of claims 1 to 16, wherein the dry weight ratio of the (a) porous particles to the (b) binder material in the dry opaque layer is at least 2:3 and up to and including 9: 1.

18. The opaque article of any of claims 1 to 17, wherein the dry coverage of the dry opaque layer is at least 50 g/cm²And up to and including 1000 g/cm²。

19. The opaque article of any of claims 1 to 18, wherein the (a) porous particles have a mode particle size of at least 3 μ ι η and up to and including 20 μ ι η and a porosity of at least 20% and up to and including 65%; and carbon black is present as (c) an opacifying colorant in the discrete pores of the (a) porous particles in an amount of at least 0.003 weight% and up to and including 0.3 weight%, based on the total weight of the dry opacifying layer.

20. The opaque article of any of claims 1 to 19, further comprising a surface finish selected from the group consisting of: flock, lubricants, antiblocking agents, antistatic agents, tactile modifiers, visual modifiers and anti-soiling agents.

21. A method of providing an opaque article according to any of claims 1 to 20, comprising:

A) providing (i) a fabric having a front side and a back side;

B) providing (ii) an opaque element comprising: a substrate having a first opposing surface and a second opposing surface; and a dry opaque layer having an inner surface and an outer surface, the dry opaque layer being disposed such that its inner surface is in contact with a first opposing surface of the substrate, an

C) Laminating the (ii) opacifying element to the back of the fabric to provide the opaque article.

22. The method of claim 21 comprising C) laminating an outer surface of the dry opaque layer of the opaque elements to a backside of the fabric.

23. The method of claim 21 comprising C) laminating a second opposing surface of the substrate to the backside of the fabric.

24. The method of any one of claims 21 to 23 wherein the opacifying element comprises a second dry opacifying layer disposed on a second, opposite surface of the substrate.

25. The method of any one of claims 21, 22 and 24, wherein an adhesive material is included in the dry opaque layer, and an outer surface of the dry opaque layer is laminated to a back surface of the fabric.

26. The method of any one of claims 21, 22 and 24 comprising C) laminating the opaque elements to the back side of the fabric using a mechanical method without an adhesive material.

27. The method of any one of claims 21 to 26 wherein the fabric comprises a material that has been treated to provide water repellency and stain resistance prior to C) lamination.

28. The process of any one of claims 21 to 27, wherein C) laminating is performed by direct calendar lamination.

29. The method of any one of claims 21 to 28, wherein the opaque elements have a dry thickness of at least 100 μm.

30. The method of any one of claims 21 to 29, wherein the substrate comprises one or more polymer films.

Technical Field

The present invention relates to the field of light barrier materials to provide blinds, curtains or other opaque articles for blocking ambient light. In particular, the present invention relates to opaque articles prepared by laminating an opaque element containing porous particles to a fabric. The invention also relates to methods of making such opaque elements using a lamination procedure.

Background

In general, when light strikes a surface, some of it may be reflected, some absorbed, some scattered, and the rest transmitted. The reflection may be diffuse, e.g. light reflecting off a rough surface in all directions (like a white wall), or specular, e.g. light reflecting off a mirror at an angle. Opaque substances are almost opaque and therefore reflect, scatter or absorb all light. Both the mirror and the carbon black were opaque. The opacity depends on the frequency of the light being considered. "blackout" or light blocking material generally refers to a coating in an article that is substantially opaque to light (e.g., visible radiation and UV radiation). Thus, when a shade material, such as a shade curtain or a shade blind, is hung on a window, it typically blocks substantially all external light from entering the room through the window. The shade material is suitable as a curtain or blind for home use, for institutional use in hospitals and nursing homes, and for commercial establishments, such as hotel, movie theater, and airplane windows, where the option of blocking light may be desirable.

Light-blocking articles (e.g., light-blocking curtains) can be composed of a fabric (porous substrate) coated with several layers of light-blocking composition. In addition to blocking transmitted light, it is also desirable that these curtains have a light color (hue) facing the environment to aid in illumination in order to minimize the amount of artificial illumination required to perform the activity. One example is when the function of the light barrier material is to separate two active areas, one or both of which may be manually illuminated at the same time. The function of a shade curtain is mostly to prevent sunlight from entering a room through a building window. It may also be desirable for the color (tint) of the side facing the window to match the exterior trim of the building.

A light shade curtain can in principle be prepared by coating a porous fabric with a light-coloured foam containing light-scattering pigments, for example titanium dioxide or clay. However, using only these pigments would require a very thick foam coating to create a shade through which the sun is not visible in a dark room. One practical approach for reducing the weight of such light-screening materials is to sandwich a light-absorbing, foamed black or gray pigment (e.g., carbon black) between two foamed, light-scattering layers containing white pigments.

When the electromagnetic radiation blocking coating between the two reflective layers has a strongly light-absorbing material containing black pigments (e.g. carbon black) as it usually has, it has at least two significant problems. First, such materials require three or more separate coating operations, which reduces manufacturing productivity and increases unit cost. Second, the carbon black in the light absorbing intermediate layer can become "escaped" (or unencapsulated) due to some puncturing or tearing that occurs during sewing or laundering, and contaminate other layers (e.g., the reflective layer), which is highly objectionable. In addition, stitches created in the material during sewing can cause the carbon black that escapes from the light absorbing layer to spread over a larger area, thereby increasing the area of objectionable shading of the light colored surface.

U.S. patents 7,754,409(Nair et al), 7,887,984(Nair et al), 8,252,414(Putnam et al) and 8,329,783(Nair et al) describe porous polymeric particles prepared by a multiple emulsion process that provides for the formation of individual porous particles comprising a continuous polymeric phase and a plurality of discrete internal pores, and such individual porous particles are dispersed in an external aqueous phase. The Evaporation Limited Coalescence (ELC) method described is used to control particle size and distribution, while incorporating hydrocolloids to stabilize the internal emulsion of a multiple emulsion that provides a template for creating discrete pores in porous particles.

U.S. patent 9,891,350(Lofftus et al) describes an improved article designed with an opaque layer applied to the substrate and capable of blocking predetermined electromagnetic radiation.

Improvements in the art are described in U.S. patent 9,469,738(Nair et al) wherein small amounts of porous particles containing small amounts of opacifying colorant can be incorporated into a transparent substrate having at least 0.1 g/cm³The foam composition of (1). Such foam compositions may be applied to a substrate to provide opacity. U.S. patent 9,963,569(Nair et al) describes a similar technique for making opaque elements using a foamed aqueous latex composition.

U.S. patent 6,884,491(Rubin et al) describes a waterproof, water resistant and stain resistant fabric that is prepared using a treatment composition laminated to a backing polymer film.

U.S. patent 6,872,276(Cherpinsky et al) describes a method of adhesively laminating a metallized coextruded polymer film to a fabric in the presence of a temporary support layer.

U.S. patent application publication 2004/0170800(Richards) describes a light shade drape fabric with a metal impregnated thermoplastic light shielding film that can be extruded or laminated to the fabric.

There is a need for further improvements to provide methods for easily preparing sunscreen articles (which can be formed by simple lamination to one side of a fabric without the need for metallization of the article) and for providing test samples of decorative sunscreen fabrics without preparing large production batches.

Summary of The Invention

The present invention provides an opaque article comprising:

(i) a fabric having a front side and a back side; and

(ii) an opaque element laminated to the backside of the fabric, the opaque element comprising: a substrate having a first opposing surface and a second opposing surface; and a dry opaque layer having an inner surface and an outer surface, the dry opaque layer being disposed such that its inner surface is in contact with a first opposing surface of the substrate,

the dry opaque layer comprises:

(a) at least 40% and up to and including 90% by weight of porous particles, each porous particle comprising a continuous polymer phase and discrete pores dispersed within the continuous polymer phase, the porous particles having a mode particle size of at least 2 μm and up to and including 50 μm and a porosity of at least 20% and up to and including 70% by volume; and

(b) at least 10% and up to and including 60% by weight of binder material,

(a) the total amount of porous particles and (b) binder material is based on the total weight of the dried opaque layer.

The present invention also provides a method for providing an opaque article according to any embodiment described herein, the method comprising:

A) providing (i) a fabric having a front side and a back side;

B) providing (ii) an opaque element comprising: a substrate having a first opposing surface and a second opposing surface; and a dry opaque layer having an inner surface and an outer surface, the dry opaque layer being disposed such that its inner surface is in contact with a first opposing surface of the substrate, an

C) (iii) laminating (ii) an opacifying element to the back of the fabric to provide an opaque article.

The present invention provides an opaque element that can be laminated to a fabric as desired to provide a spatially "darkened" opaque article without the need for latex foam or a metallized layer. Such opacifying elements can be provided in short-term or long-term batches, minimizing waste of expensive textile substrates to which the opacifying elements can be easily applied or laminated. The present invention eliminates the need to sew an additional shade liner and attach it to the fabric substrate. Furthermore, in the event that a designer needs a test sample of shade material derived from a decorative fabric to simulate a room, lamination or various opaque elements on a decorative fabric of a desired size becomes more economical than subjecting many decorative fabrics to a coating conversion that may not be suitable for decoration until after completion. In a sense, the present invention provides a means for "verifying" the consumer's expectations without the use of foamed opaque compositions that are directly coated onto the fabric substrate. The present invention enables a manufacturer or supplier to test product samples at low cost.

Brief Description of Drawings

Fig. 1A illustrates a partial cross-sectional view of a fabric having a front side and a back side and an opaque element according to the present invention having a dry opaque layer disposed on a first opposing surface of a substrate.

Fig. 1B illustrates a partial cross-sectional view of an opaque article formed from the fabric and opaque elements of fig. 1A, wherein the dry opaque layer disposed on a first opposing surface of the substrate is disposed in contact (laminated) with the backside of the fabric.

Fig. 2A illustrates a partial cross-sectional view of a fabric having a front side and a back side and an opaque element according to the present invention having a dry opaque layer disposed on a second, opposite surface of the substrate.

Fig. 2B illustrates a partial cross-sectional view of an opaque article formed from the fabric of fig. 2A and opaque elements, wherein a dry opaque layer is disposed on a second opposing surface of the substrate and the opaque elements are arranged such that the first opposing surface of the substrate is in contact with (laminated to) the back surface of the fabric.

Fig. 3A illustrates a partial cross-sectional view of a fabric having a front side and a back side and an opacifying element according to the present invention having two dry opacifying layers disposed on first and second opposing surfaces thereof.

Fig. 3B illustrates a partial cross-sectional view of an opaque article formed from the fabric and opaque elements of fig. 3A, wherein one of the dry opaque layers disposed on the substrate is disposed in contact (laminated) with the backside of the fabric.

Fig. 4A and 4B illustrate partial cross-sectional views of embodiments of the present invention similar to those in fig. 1A and 1B, except for the incorporation of an adhesive layer between the fabric and the opaque element.

Detailed Description

The following discussion is directed to various embodiments of the invention, and although some embodiments may be desirable for particular uses, the disclosed embodiments should not be interpreted, or otherwise regarded, as limiting the scope of the invention as claimed below. In addition, those skilled in the art will understand that the following disclosure may have broader application than what is explicitly described or discussed with respect to any particular embodiment.

Definition of

As used herein to define the singular forms of the various components of the dry opaque layer (i.e., (a) porous particles, (b) binder material, (c) opacifying colorant and other materials used in the practice of the present invention), "a" and "the" are intended to include one or more components (i.e., including multiple referents) unless otherwise indicated.

Terms not explicitly defined in the present application should be understood to have the meaning commonly accepted by a person skilled in the art. A term should be interpreted as having a standard dictionary meaning if its construction renders it meaningless or substantially meaningless in its context.

The use of numerical values in the various ranges specified herein is considered approximate, as if the word "about" preceded both the minimum and maximum values in the stated ranges, unless expressly stated otherwise. In this manner, minor variations above and below the stated ranges may be useful in achieving substantially the same results as values within the ranges. In addition, the disclosure of these ranges is intended as a continuous range including every value between the minimum and maximum values as well as the endpoints of such ranges.

Unless otherwise indicated, the terms "dry opaque composition" and "dry opaque layer" are intended to refer to the same feature.

Unless otherwise indicated, the term "porous particles" is used herein to refer to porous polymeric materials that can be used in the dry opaque compositions necessary for the present invention. The porous particles generally comprise a solid continuous polymeric phase having an outer particle surface and discrete pores dispersed within the continuous polymeric phase. The continuous polymeric phase may also be chemically crosslinked or elastomeric in nature.

The continuous polymer phase of the porous particles typically has the same composition throughout the solid phase. That is, the continuous polymer phase is generally homogeneous in the composition including any components [ e.g., (c) opacifying colorant ] that may be incorporated therein. In addition, if mixtures of polymers are used in the continuous polymer phase, typically those mixtures are also uniformly dispersed throughout.

As used in this disclosure, the term "isolated from each other" refers to different (distinct) pores of the same or different size that are separated from each other by certain portions of the continuous solid phase, and such discrete pores are not interconnected. Thus, "discrete" pores refer to "individual" or "closed" unconnected pores or voids distributed within a continuous polymer phase.

The terms "first discrete pores" and "second discrete pores" refer to (a) distinct sets of isolated discrete pores (individual isolated and closed voids or chambers) in a porous particle. Each distinct set of pores is isolated from other discrete pores in the distinct set of pores, and each distinct set of pores is isolated from (a) all other discrete pores of the other distinct set of pores in the porous particle. Each distinct set of discrete holes may have the same mode average size, or both sets may have the same mode average size. For the preparation of such (a) porous particles, the word "discrete" may also be used to define different droplets of the first and second aqueous phases when they are suspended in the oil (solvent) phase (described in the art cited below).

In the presence of a different set of discrete pores, the first set of discrete pores may be predominately closer to the outer porous particle surface than the second set of discrete pores. For example, a set of smaller discrete holes may be predominantly near the outer particle surface as compared to a set of larger discrete holes. The term "predominantly" as used herein means that a greater number of discrete pores of one size are found in the "shell" region closer to the surface of (a) the porous particle than one would expect based on the total number fraction of discrete pores of two or more types (sizes) present in (a) the porous particle.

(a) Porous particles may include "micro," meso, "" and "macro" discrete pores, which are recommended by the International Union of Pure and Applied Chemistry for the classification of discrete pore sizes of less than 2 nm, 2 nm to and including 50 nm and greater than 50 nm, respectively. Thus, while (a) the porous particles may include closed discrete pores of all sizes and shapes that provide a suitable volume (volume) in each discrete pore (i.e., closed, unconnected discrete pores entirely within the continuous polymer phase), large discrete pores are particularly useful. Although open macropores may be present on the surface of (a) the porous particles, such open pores are undesirable and may be present only by chance. (a) The size of the porous particles, their formulation and manufacturing conditions are the primary controlling factors for the discrete pore size. Typically, however, the discrete pores have an average size of at least 100 nm and up to and including 7,000 nm, or more likely at least 200 nm and up to and including 2,000 nm. Regardless of the size of the discrete pores, they are generally randomly distributed throughout the continuous polymer phase. However, if desired, the discrete pores may be predominately classified as (a) a portion of the porous particle (e.g., "core" or "shell").

The (a) porous particles used in the present invention typically have a porosity of at least 20 vol% and up to and including 70 vol%, or possibly at least 35 vol% and up to and including 65 vol%, or more typically at least 40 vol% and up to and including 60%, all based on the total volume of the porous particles. Porosity can be measured by a modified version of the known mercury intrusion technique.

Unless otherwise indicated, the term "non-porous" refers to particles that are not designed to have discrete pores or cavities within the solid continuous polymer phase and are comprised of pores less than 20% of their total volume.

"opacity" is a measured parameter of the opaque element according to the invention that characterizes the degree of transmission of the blocked electromagnetic radiation (e.g. visible light). Greater opacity indicates more effective blocking (hiding) of electromagnetic radiation (as described below). In the present invention, the "opacity" of an opaque element is quantified by measuring the Optical Density (OD) (described below with respect to the embodiments) which determines the degree to which impinging radiation or light is blocked by the opaque element. The higher the OD, the greater the light blocking ability exhibited by the opaque element.

The glass transition temperature of the organic polymer used to prepare the continuous polymeric phase described below, or (b) the binder material, can be measured using Differential Scanning Calorimetry (DSC) using known procedures. For many commercially available organic materials, the glass transition temperature is known from the supplier.

The polymer viscosity (in centipoise or mPa · s) of a polymer comprising a continuous polymer phase can be measured in an Anton Parr MCR 301 stress rheometer using a stable shear scan in a couette cell at a polymer concentration of 20 wt.% in ethyl acetate at 25 ℃. From the obtained plot of viscosity vs. shear rate, 100 s was calculated^-1Shear rate of (b).

The CIELAB L, a, and b values described herein have known definitions according to the CIE 1976 color space or later known color space versions and are calculated assuming the standard D65 light source and known procedures. These values can be used to express color in three color values: l is for the lightness (or brightness) of a color, a is for the green-red component of a color, and b is for the blue-yellow component of a color value.

The term "fabric" as used herein is intended to mean a material composed of or prepared from naturally occurring fibers, synthetic fibers, or a mixture of naturally occurring and synthetic fibers of any desired length.

Use of

The method according to the present invention can provide a means for easily preparing an opaque film (or element) that can be laminated to the back of a fabric to provide a light-blocking decorative fabric or a specific opacity and color. Opaque articles according to the present invention can be used as light blocking materials for various environments and structures. Such opaque articles may also exhibit improved sound and thermal insulation properties. They may be used, for example, as curtains and other window treatments, carpets, curtains, screens, booth curtains, banners, labels, projection screens, clothing, covers and tarpaulins (e.g., for vehicles, boats and other items), and packaging materials. The opaque article may optionally have a printable outer surface that is capable of receiving inks used in screen printing, gravure printing, ink jet printing, thermal imaging (e.g., "dye sublimation thermal transfer"), or other imaging methods. Thus, one can provide a printable surface in such opaque articles, such that the printed image on the back side (non-viewer side) is generally not viewable from the "front" or viewer side.

Opaque article

The present invention may be understood, at least in part, from the illustrations shown in fig. 1A, 1B, 2A, 2B, 3A, 3B, 4A, and 4B.

In fig. 1A, a partial cross-sectional view of a fabric 10 is illustrated having a back side 15 and a front side 20. The opacifying element 25 has a substrate 30 and a dry opacifying layer 45, the substrate 30 having a first opposing surface 35 and a second opposing surface 40, the dry opacifying layer 45 having an outer surface 46 and an inner surface 47 in contact with (or disposed on) the first opposing surface 35.

Fig. 1B shows an opaque article 50 formed by: the web 10 and the opacifying elements 25 are brought together (e.g. by lamination) such that the outer surface 46 of the dry opacifying layer 45 is arranged in contact (e.g. laminated) with the back surface 15 of the web 10.

In fig. 2A, a partial cross-sectional view of the fabric 10 is illustrated as having a back side 15 and a front side 20. Opaque element 55 has a substrate 30 having a second opposing surface 60 and a first opposing surface 65. A dry opaque layer 45 having an inner surface 47 and an outer surface 46 is disposed such that the inner surface 47 is in contact with a second opposing surface 60 of the substrate 30.

Fig. 2B shows an opaque article 70 formed by: the web 10 and opaque element laminate 55 are brought together (e.g., by lamination) such that the first opposing surface 65 is disposed in contact with the back side 15 of the web 10 (laminated to the back side 15 of the web 10).

In fig. 3A, a partial cross-sectional view of a substrate 10 is illustrated having a back side 15 and a front side 20. The opaque member 75 has a substrate 30 having a first opposing surface 35 and a second opposing surface 80. A dry opaque layer 45 having an inner surface 47 and an outer surface 46 is disposed in contact with the first opposing surface 35. The opacifying element 75 also has a second dry opacifying layer 85 having an inner surface 86 and an outer surface 87, wherein the inner surface 86 is arranged in contact with the second opposing surface 80. The dry opaque layer 45 and the dry opaque layer 85 may be the same or different in composition, dry thickness, and opaque effect.

Fig. 3B shows an opaque article 90 formed by: the web 10 and the opacifying element laminate 75 are brought together (e.g. by lamination) such that the dry opacifying layer 45 is disposed with its outer surface 46 in contact with the back surface 15 of the web 10.

In fig. 4A, a partial cross-sectional view of a fabric 100 is illustrated having a back side 110, a front side 115, and an adhesive 120 disposed on the back side 110. The opacifying element 25 has a substrate 30 and a dry opacifying layer 45, the substrate 30 having a first opposing surface 35 and a second opposing surface 40, the dry opacifying layer 45 having an outer surface 46 and an inner surface 47 disposed on the first opposing surface 35.

Fig. 4B shows an opaque article 125 formed by: the web 100 and the opacifying elements 25 are brought together such that the outer surface 46 of the dry opacifying layer 45 is arranged to be in contact with the adhesive layer 120 provided on the back surface 110 of the web 100.

Other structure embodiments not illustrated in these figures are also possible, including but not limited to opaque articles similar to opaque article 125, but further comprising a second dry opaque layer disposed on second opposing surface 40 of substrate 30.

Additionally, an adhesive material may be disposed on the outer surface 47 of the dry opaque layer 45 rather than on the back surface 110 of the fabric 100, or an adhesive material may be incorporated within the dry opaque layer 45. Therefore, the skilled artisan can use the teachings and routine experimentation to design other useful structural embodiments, all of which are intended to be within the scope of the present invention.

As exemplified in the depicted figures, opaque articles according to the present invention are generally planar in nature, with smooth or irregular (with small depressions and elevations) outer surfaces.

Fabric

Each fabric used in the practice of the present invention has a front side (typically the visible or viewer side) and a back side. The two opposing faces may be the same or different in appearance, texture, feel or composition, but back and front labels are used to distinguish how the opaque elements are arranged relative to the web, as exemplified in the figures referred to above.

The fabric may be in the form of a woven or nonwoven material comprised of naturally occurring fibers, synthetic fibers, or a mixture of naturally occurring and synthetic fibers. Suitable naturally occurring fibers include, but are not limited to, fibers of cotton, flax, ramie, silk, wool, and other fibers known in nature, as well as blends of fibers of such naturally occurring materials. Suitable synthetic fibers include, but are not limited to, fibers of nylon, polyester, acrylics, glass, polyurethane, polyamide, polycarbonate, rayon, polyolefin, cellulose (including woven or non-woven paper materials), acetate, aramid, polyvinyl chloride, and others known in the art, as well as combinations or blends of any of these types of fibers, such as fibers of various materials coated with polyvinyl chloride. Useful fabrics may be composed of polyvinyl chloride coated polyester or polyvinyl chloride coated glass fibers. Suitable fabric materials include, but are not limited to, jacquard (i.e., fabric made on a jacquard loom), satin, dobby, printed calico, poplin, crossply (cross-dye), crepe, and canvas.

In some embodiments, the fabric is a porous fabric comprising a plurality of continuous yarn bundles (yarn strand) all woven together, wherein each yarn bundle comprises a multifilament core coated with a coating comprising a thermoplastic polymer. Further details of such fabrics and their use are provided in co-pending and commonly assigned U.S. serial No. 15/943,770 (filed by Nair, Brick, and Sedita at 2018 on day 4, 3).

In many embodiments, the fabric may comprise a material that has been treated in one or more ways to provide water repellency or stain resistance, or both. For example, such treatment may include applying a suitable fluorochemical treatment (with or without a suitable antimicrobial agent (or biocide)) to the front and back of the fabric material and to the interstitial spaces within the fabric material to provide a "treated" fabric, which is then suitably dried or cured at elevated temperatures. Representative treatment methods are described in columns 4-6 of U.S. patent 6,884,491 (referenced above) and column 6ff of U.S. patent 6,541,138(Bullock et al). The treatment solution may include one or more biocides (e.g., antimicrobials), crosslinkers (including self-crosslinking latex polymers), flame retardants, smoke suppressants, dispersants, thickeners, dyes, pigments, UV light stabilizers, and other additives that will be readily apparent to those skilled in the art.

For example, the textile material may be treated with at least one or more biocides capable of destroying or preventing the activity of bacteria, viruses, fungi or molds, many of which are known in the art, including antibiotics, trialkyltin compounds, copper complexes of dehydroabietylamine or 8-hydroxyquinolinium 2-ethylhexanoate, copper naphthenate, copper oleate, silicone quaternary compounds, silver metal and various silver salts.

The fabric material may be subjected to one or more treatments to achieve desired properties while maintaining desired hand, feel, texture, drape, and aesthetic appearance.

In general, suitable fabrics may have an average dry thickness of at least 50 μm, and this thickness may depend on the use of the opaque article and the type of fabric material that may be utilized. The average dry caliper can be determined using the average of at least 3 measurements taken at different locations when the fabric contains less than 5 wt% water (based on the total weight of the fabric), or using suitable microscopic image determinations.

The fabric used in the opaque article may also have an openness (openness) of at least 0% and up to and including 10%, or even at least 1% and up to and including 10%. "openness" (openness factor or OF) refers to the tightness OF weaving OF the fabric material, the percentage OF holes in the fabric structure, and sometimes "weaving density". The lower OF, the less light transmittance and the more visible light that is blocked or obstructed. It is the ratio between the transparent surface and the opaque surface and depends on the spacing and size of the yarns.

Opaque element

The opaque elements used in the present invention comprise a substrate (or two opposing flat sides) having a first opposing surface and a second opposing surface. As shown in some figures, a dry opaque layer may be disposed on either or both of the first and second opposing surfaces.

As described above, the opaque elements are arranged to contact (e.g., laminate) to the back side of the fabric. In some embodiments, such an arrangement may represent adhering the opaque elements to the back of the fabric using a suitable adhesive material (see below).

The substrate for the opaque element typically comprises a material suitable for use in a lamination process. Useful substrates can be composed of a variety of materials including, but not limited to, synthetic or non-synthetic (naturally occurring) polymers or copolymers (typically organic materials) or blends of polymers or copolymers, and can generally be provided in the form of polymeric films having single or multiple polymeric layers (e.g., laminated structures). Representative useful polymeric materials include, but are not limited to, nylon or other polyamides; polyesters (e.g., polyethylene terephthalate); glass, aramid (aramide), rayon, acrylic, cellulosic materials (e.g., triacetyl cellulose, diacetyl cellulose, cellulose acetate butyrate, and cellulose acetate propionate), polyethersulfone, polyacrylic-based resins (e.g., polymethyl methacrylate), polyurethane-based resins, polycarbonate, aramid, acyclic polyolefins (e.g., polyethylene and polypropylene), polyvinylidene chloride, polycaprolactam, polymers derived from vinyl chloride (e.g., polyvinyl chloride and vinyl chloride/vinyl acetate copolymers), polyvinyl alcohol, polyvinyl acetate (e.g., ethylene-polyvinyl acetate), silicone resins, polystyrene, and polymers derived from styrene derivatives, polysulfone, polyether; cyclic olefin polymers such as polynorbornene; polymethylpentene, polyetherketone, (meth) acrylonitrile ], and other organic polymeric film-forming materials that will be apparent to those skilled in the art.

The substrate may be formed from a single film (e.g., a single polymeric film), or it may be a "laminate" or planar composite of multiple polymeric films composed of the same or different chemical or physical compositions.

Either or both of the first and second opposing surfaces of the substrate may be surface treated by various methods, including corona discharge, glow discharge, UV or ozone exposure, combustion or solvent washing, in order to promote the desired physical properties and adhesion of the dried light-blocking composition. An adhesive material may be disposed on the fabric (back) or the opaque elements to provide an intermediate adhesive layer and promote adhesion between the fabric and the opaque elements. Useful adhesive materials are described below.

The substrate may comprise a primer layer comprising one or more polymers designed to promote adhesion of the dry opaque layer or to the fabric.

It may be desirable for the substrate to be "transparent," meaning that incident radiation will pass through the substrate with minimal absorption by the substrate material. This transmission property can be measured by passing light through the substrate and comparing the intensity of the transmitted radiation with the intensity of the incident radiation with a UV-visible spectrophotometer or transparence meter.

As described in several of the figures described above, a dry opaque layer according to the present invention is disposed on one or both of the first and second opposing surfaces of the substrate. For example, as illustrated in fig. 3A, both the first and second opposing surfaces of the substrate may have the same or different dry opaque layers disposed thereon. In this context, the term "different" is meant to include differences in composition components or amounts, layer coverage, or both.

Each dry opaque layer useful in the present invention has two essential components (a) and (b), as defined below, which are necessary to provide the desired properties when incorporated as part of an opaque element or opaque article. However, drying the opaque layer may have further advantages by incorporating therein (c) an opaque colorant or one or more additives (e), or both (c) and (e), as defined below, so long as they do not interfere with the properties and purposes of the essential components (a) and (b). The opacifying composition used to provide the dry opacifying layer is typically formulated in (d) water and then applied to the laminate substrate in a suitable manner (as described below). An advantage of the present invention is that these aqueous opacifying compositions are not "foamed" before they are applied to a substrate as in prior art methods (e.g., as described in 9,469,738 (mentioned above)), thereby simplifying the manufacture and use of opacifying articles according to the present invention.

With respect to drying the opaque layer, the term "drying" means that the layer comprises water or an auxiliary solvent (described below) in an amount of less than 5 wt% or even less than 1 wt%, based on the total weight of the dried opaque layer.

Usually at least 50 g/m²And up to and including 1000 g/m²Or at least 100 g/m²And up to and including 500 g/m²Dry coverage each dry opaque layer is disposed on an opposite surface of the substrate.

The opaque elements typically have a dry thickness of at least 100 μm or more likely at least 300 μm, the dimensions being intended to include the substrate, the one or more dry opaque layers, any intermediate adhesive layers, and any other materials adhered thereto. The average dry thickness may be determined by: after drying, the opaque element thickness is suitably measured at least three different locations and the measurements averaged.

(a) Porous particles:

the porous particles containing discrete pores (or compartments or voids) used in the present invention are typically prepared using one or more water-in-oil emulsions in combination with an aqueous suspension process, for example, in an Evaporative Limited Coalescence (ELC) process as is known in the art. Details regarding the preparation of porous particles are provided in, for example, U.S. patents 8,110,628(Nair et al), 8,703,834(Nair), 7,754,409(Nair et al), 7,887,984(Nair et al), 8,329,783(Nair et al), and 8,252,414(Putnam et al). Thus, (a) porous particles are typically polymeric and organic in nature (i.e., the continuous polymeric phase is polymeric and organic in nature), and use of non-porous particles (having a porosity of less than 20%) is excluded in the present invention. If desired, inorganic particles may be present on the outer surface of each porous particle.

(a) The porous particles can consist of a continuous polymeric phase derived from one or more organic polymers selected such that the continuous polymeric phase has a glass transition temperature (T) of at least 25 ℃, or more typically at least 25 ℃ and up to and including 180 ℃, as determined using differential scanning calorimetry_g)。

The continuous polymeric phase may comprise one or more organic polymers having the properties mentioned above, typically at least 70 wt% and up to and including 100 wt%, based on the total weight of polymers in the continuous polymeric phase. In some embodiments, the continuous polymer phase is composed of one or more cellulose polymers (cellulose polymers or cellulose polymers) including, but not limited to, those derived from one or more of cellulose acetate, cellulose butyrate, cellulose acetate butyrate, and cellulose acetate propionate. Mixtures of these cellulosic polymers can also be used, if desired, and mixtures comprising at least 80% by weight of the total cellulosic polymer (or all polymers in the continuous polymeric phase) of a polymer derived from cellulose acetate butyrate are particularly useful mixtures. Details regarding such polymers are provided, for example, in U.S. patent 9,963,569(Nair et al).

In other embodiments, the continuous polymer phase may comprise one or more organic polymers, such as polyesters, styrenic polymers (e.g., polystyrene and polychlorostyrene), monoolefin polymers (e.g., polymers formed from one or more of ethylene, propylene, butylene, and isoprene), vinyl ester polymers (e.g., polymers formed from one or more of vinyl acetate, vinyl propionate, vinyl benzoate, and vinyl butyrate), polymers formed from one or more alpha-methylene aliphatic monocarboxylic acid esters (e.g., polymers formed from one or more of methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, and dodecyl methacrylate), and the like, Vinyl ether polymers (e.g., polymers formed from one or more of vinyl methyl ether, vinyl ethyl ether, and vinyl butyl ether), and vinyl ketone polymers (e.g., polymers formed from one or more of vinyl methyl ketone, vinyl hexyl ketone, and vinyl isopropenyl ketone). Other useful polymers include polyurethanes, urethane acrylic copolymers, epoxy resins, silicone resins, polyamide resins, and polyesters of aromatic or aliphatic polycarboxylic acids with one or more aliphatic diols, for example, the bisphenol adducts of isophthalic or terephthalic acid or fumaric acid with diols such as ethylene glycol, cyclohexanedimethanol, and ethylene oxide or propylene oxide. The polyester may be saturated or unsaturated. Other useful polyesters include lactic acid polymers, glycolic acid polymers, caprolactone polymers and hydroxybutyric acid polymers. Details of such useful polymers are provided, for example, in U.S. Pat. Nos. 9,891,350(Lofftus et al) and 9,469,738(Nair et al).

(a) The continuous polymeric binder of the porous particles may also be derived from ethylenically unsaturated polymerizable monomers and polyfunctional reactive compounds as described, for example, in U.S. patent 8,703,834(Nair et al).

Generally, the (a) porous particles used in the present invention have a mode particle size equal to or less than 50 μm, or at least 2 μm and up to and including 50 μm, or typically at least 3 μm and up to and including 30 μm or even up to and including 40 μm. The most useful (a) porous particles have a mode particle size of at least 3 μm and up to and including 20 μm. The mode particle size represents the diameter in the particle size distribution histogram that occurs most frequently for spherical particles, and the largest diameter that occurs most frequently for non-spherical particles, which can be determined using known equipment (including light scattering equipment, such as the Sysmex FPIA 3000 flow-type particle image analyzer measured using image analysis and available from various sources including Malvern Panalytical, and Coulter counter and other particle characterization equipment available from Beckman Coulter Diagnostics), software and programs.

Pore stabilizing materials (e.g., hydrocolloids) may be present within at least a partial volume of the discrete pores distributed throughout the continuous polymer phase, which are described in Nair, Nair et al, and Putnam et al, referenced above. For example, the pore stabilizing hydrocolloid may be selected from carboxymethylcellulose (CMC), gelatin or gelatin derivatives, proteins or protein derivatives, polyvinyl alcohol and its derivatives, hydrophilic synthetic polymers and water soluble microgels.

In some embodiments, it may be desirable to provide (a) additional stability of one or more discrete pores in the porous particle during its formation by having one or more amphiphilic block copolymers disposed at the interface of the one or more discrete pores and the continuous polymeric phase. Such materials are "low HLB," which means that they have an HLB (hydrophilic-lipophilic balance) value of 6 or less, or even 5 or less, as calculated using known science. Details of these amphiphilic polymers and their use in the preparation of (a) porous particles are provided in U.S. patent 9,029,431(Nair et al). Particularly useful amphiphilic block copolymers that can be used in such embodiments comprise polyethylene oxide and polycaprolactone, which can be represented as PEO-b-PCL. Amphiphilic block, graft, and random graft copolymers containing similar components are also useful, including other polymeric emulsifiers, such as GRINDSTED^®PGPR 90 (polyglycerol polyricinoleate emulsifier available from Danisco, Dupont).

Such amphipathic copolymers may typically be present in the (a) porous particles in an amount of at least 1 wt% or at least 2 wt% and up to and including 50 wt%, based on the total dry weight of the (a) porous particles.

The (a) porous particles used in the present invention may be spherical or non-spherical depending on the intended use. In the process for preparing (a) porous particles, additives (shape control agents) may be incorporated into the first or second aqueous phase or the oil (organic) phase using known techniques to modify the shape, aspect ratio or morphology of (a) porous particles. (a) The porous particles may also comprise a surface stabilizer (e.g., colloidal silica) on the outer surface in an amount of at least 0.1 weight percent based on the total dry weight of the (a) porous particles.

The average size of the discrete pores in (a) the porous particles is described above.

The (a) porous particles may be provided as a powder or as an aqueous suspension comprising water or water and a water-miscible organic solvent, such as an alcohol. Such powders and aqueous suspensions may also include surfactants or suspending agents to keep (a) the porous particles suspended in the aqueous medium or to re-wet them in the aqueous medium.

The (a) porous particles are typically present in the dried opaque layer in an amount of at least 40 wt% and up to and including 90 wt%, or typically at least 50 wt% and up to and including 70 wt%, based on the total weight of the dried opaque layer (including any residual aqueous medium), particularly when the (a) porous particles have a mode size of at least 3 μm and up to and including 20 μm.

In the dry opaque layer (a) a large mismatch in refractive index between the discrete pores of the porous particles and the polymer wall (continuous polymer phase) causes incident electromagnetic radiation passing through the dry opaque layer to be scattered by the plurality of interfaces and discrete pores. The backscattered electromagnetic radiation may again be scattered and returned in the direction of the incident electromagnetic radiation, thereby reducing attenuation and contributing to the opacity and brightness or light reflectivity of the dried opaque layer. The opacifying power of a dry opacifying (layer) is increased if a small amount of (c) opacifying colorant is present in (a) the porous particles, for example in the discrete pores or in the continuous polymer phase of (a) the porous particles. This is because multiple scattering of the electromagnetic radiation in the dry opaque layer increases the path length of the electromagnetic radiation through the dry opaque layer, thereby increasing the chance that the electromagnetic radiation will encounter, be blocked or absorbed by (c) the opaque colorant.

Some particularly useful (a) porous particles comprise a continuous polymer phase and discrete pores dispersed within the continuous polymer phase, wherein:

each (a) porous particle has a mode particle size of at least 3 μm and up to and including 20 μm;

each (a) porous particle has a porosity of at least 35 volume percent and up to and including 65 volume percent;

the continuous polymeric phase comprises one or more polymers in an amount of at least 70 wt%;

the discrete pores have an average size of at least 50 nm and up to and including 2,000 nm;

(a) the porous particle further comprises a pore stabilizing hydrocolloid selected from the group consisting of carboxymethylcellulose, gelatin, a protein or protein derivative, polyvinyl alcohol or a derivative thereof, a hydrophilic synthetic polymer, and a water soluble microgel within at least a portion of the volume of the discrete pores; and is

(a) The porous particles comprise one or more amphiphilic low HLB block copolymers disposed at the interface of one or more discrete pores and the continuous polymeric phase.

(b) Adhesive material:

the dry opaque layer also contains one or more (b) binder materials to hold together on the substrate (a) the porous particles, any (c) opacifying colorant, and any (e) additive.

Particularly useful are (b) binder materials having the following properties: (i) it is water soluble or water dispersible; (ii) it can be provided on a suitable substrate as described below; (iii) it can be dried and at least partially cross-linked (or at least partially cured); (iv) it has good light stability and thermal stability; and (v) it is film-forming but contributes to the flexibility of the opaque element and is therefore not too brittle, e.g. typically has a glass transition temperature (T) below 25 ℃ as determined using differential scanning calorimetry_g) Or less than 0 ℃, or less than or equal to-10 ℃, or less than or equal to-25 ℃ of T_g。

(b) The binder material may comprise one or more organic polymers which are film-forming and may be provided as an emulsion, dispersion or aqueous solution and which cumulatively provide the above-mentioned properties. It may also comprise a polymer that is self-crosslinking, or it may comprise one or more polymers that are self-crosslinking or self-curable, or it may comprise one or more polymers to which a crosslinking agent is added and which are therefore curable or capable of being at least partially crosslinked under the appropriate conditions.

Thus, if (b) the adhesive material is crosslinkable (or curable) in the presence of a suitable crosslinking agent or catalyst, such crosslinking (or curing) may be chemically activated by heat, radiation, or other known means. The curing or crosslinking process serves to provide improved insolubility of the resulting dried opaque layer, as well as cohesive strength and adhesion to the substrate. The curing or crosslinking agent is typically a chemical having the following functional groups: the functional group is capable of reacting with (b) reactive sites in the binder material (e.g., functionalized latex polymer) under curing conditions to thereby produce a crosslinked structure. Representative crosslinking agents include, but are not limited to, polyfunctional aziridines, aldehydes, hydroxymethyl derivatives, and epoxides.

Useful (b) binder materials include, but are not limited to, polyvinyl alcohol, polyvinyl pyrrolidone, ethylene oxide polymers, polyurethanes, urethane-acrylic copolymers, other acrylic polymers, styrene-acrylic copolymers, vinyl polymers, styrene-butadiene copolymers, acrylonitrile copolymers, and polyesters, silicone polymers, or combinations of two or more of these organic polymers. Such (b) binder materials are readily available from various commercial sources or may be prepared using known starting materials and synthesis conditions. (b) The binder material may be anionic, cationic or nonionic in terms of overall charge. One class of useful film-forming (b) materials includes aqueous latex polymer dispersions, such as acrylic latexes, which may be ionic or nonionic colloidal dispersions of acrylate polymers and copolymers. Useful film-forming aqueous latexes include styrene-butadiene latexes, polyvinyl chloride and polyvinylidene chloride latexes, polyvinyl pyridine latexes, polyacrylonitrile latexes, and latexes formed from acrylonitrile, butyl acrylate, and ethyl acrylate.

The one or more (b) binder materials may be present in the dry opaque layer in an amount of at least 10 wt% and up to and including 60 wt%, or typically at least 20 wt% and up to and including 50 wt%, based on the total dry opaque layer (i.e., the total weight of all components including any residual solvent).

Usefully, the dry weight ratio of (a) porous particles to (b) binder material in the dry opaque layer is at least 2:3 and up to and including 9:1, and more likely at least 1:1 and up to and including 3: 1.

(c) Opaque colorant:

the use of (c) an opaque colorant in the dry opaque layer is desirable for blocking or absorbing incident electromagnetic radiation in a wavelength range of at least 380 nm and up to and including 800 nm. (c) The opacifying colorant may be a soluble dye or pigment or a combination of each type or both types of materials. The amount of electromagnetic radiation that can be blocked or absorbed by the opacifying colorant can be determined by measuring opacity as described below. The opacifying colorant can be a single colorant or a combination of materials that collectively act as an "opacifying colorant".

In many embodiments, one or more (c) opacifying colorants are present within (a) the porous particles, e.g., within (a) the volume of at least some, if not all, of the discrete pores within the porous particles, or incorporated within (a) the continuous polymeric binder of the porous particles, or within both (a) the volume of the discrete pores of the porous particles and the continuous polymeric binder. This is very advantageous because (a) the porous particles can be used to "encapsulate" various (c) opacifying colorants as well as tinting colorants and other (e) additives (described below), such that they remain isolated from the other components of the dried opacifying layer. In some embodiments, it may be useful to incorporate (c) an opacifying agent, alone or in addition, into (b) the binder material in which (a) the porous particles are dispersed.

While (c) opacifying colorants may provide some coloration or desired shade, they are not intentionally selected for this purpose and are therefore materials selected to be different from the optional tinting colorants described below.

Examples of (c) opacifying colorants that can be used alone or in combination include, but are not limited to, neutral or black pigments or dyes, carbon black, black iron oxide, graphite, aniline black, anthraquinone black, and combinations of colored pigments or dyes (e.g., cyan, magenta, yellow, green, orange, blue, red, and violet dyes). The present invention is not limited to the specific (c) opacifying colorants described herein, but these are considered suitable guidance to the skilled person in formulating other combinations of (c) opacifying colorants for the desired absorption within the chosen range of electromagnetic radiation. Carbon black or neutral or black pigments or dyes other than carbon black, of which there are many types available from commercial sources, are particularly useful as (c) opacifying colorants.

(c) The opacifying colorant can generally be present in the dried opacifying layer in an amount of at least 0.001% and up to and including 0.5%, or even at least 0.003% and up to and including 0.3% by weight, all based on the total weight of the dried opacifying layer (including any aqueous medium). For mixtures of materials which can be used if desired, these amounts also refer to the total amount of the mixture of materials used as (c) opacifying colorant. As mentioned above, (c) the opaque colorant may comprise a combination of two or more component materials (e.g., a combination of dyes or a combination of pigments) designed in hue and amount such that the combination meets the desired opacifying and coloring properties described herein.

In some embodiments, the (c) opacifying colorant, if in pigmentary form, is typically milled to a fine particle size and then encapsulated within the volume of the discrete pores of the (a) porous particles by incorporating the milled pigment into the aqueous phase used to prepare the (a) porous particles. Alternatively, (c) the opacifying colorant may be incorporated into the continuous polymeric phase of (a) the porous particles by incorporating the (c) opacifying colorant into the oil phase used to prepare (a) the porous particles. Such an arrangement may be achieved during the manufacture of (a) the porous particles using the teachings provided herein and the teachings provided in the references cited above for the preparation of (a) the porous particles.

In some embodiments, it may be useful to incorporate at least 95% (by weight) of the total (c) opacifying colorant into (a) the volume of the porous particles (in the discrete pores, the continuous polymeric phase, or both) and to incorporate the remainder, if any, into (b) the binder material. However, in many other embodiments, 100% of (c) the opacifying colorant is incorporated into (a) the porous particles. For example, more than 50% of the total (c) opacifying colorant may be disposed within or incorporated into the (a) continuous polymeric phase of the porous particles, and the remainder may be incorporated into the volume of the discrete pores. Alternatively, all (c) of the opacifying colorant may be incorporated within the volume of the discrete apertures.

(d) Aqueous medium:

after an aqueous formulation (described below) has been applied to one or both of the opposing surfaces of the substrate and dried, the aqueous medium (including water or an auxiliary solvent (described below)) remaining in the dried light-barrier composition desirably is less than 5 wt% or even less than 2 wt% of the total weight of the dried opaque layer.

(e) Optional additives:

optionally, the dried opaque layer according to the present invention may further comprise at least 0.0001 wt% and up to and including 20 wt%, and typically at least 1 wt% and up to and including 15 wt%, based on the total weight of the dried opaque layer (including any residual aqueous medium), of a combination of (e) additives that are not (a) porous particles, (c) an opacifying colorant, or (b) a binder material. Such (e) additives include, for example, the following materials: dispersants, plasticizers, inorganic or organic pigments and dyes (e.g., pigments or dye colorants other than the opaque colorant (c) described above), flame retardants, biocides (e.g., fungicides and antimicrobials), preservatives, thickeners, pH buffers, optical brighteners, tinting colorants, flocking agents, thickeners, and inert inorganic and organic fillers that are not inorganic or organic pigments (colorants). The amounts mentioned refer to the total amount of all (e) additives. Mixtures of each type of (e) additive or mixtures of two or more types of (e) additives may be present in each dry opaque layer.

Such (e) additives are different from (c) opacifying colorants in that, individually or collectively, they will not substantially block or absorb incident electromagnetic radiation in the wavelength range of at least 380 nm and up to and including 800 nm, as determined in the manner described above for (c) opacifying colorants.

Any of these (e) additives may be present in any location of the dried opaque layer including, but not limited to: (a) a continuous polymeric phase of porous particles; (a) the volume of some or all of the discrete pores of the porous particle; or (a) both the volume of the discrete pores of the porous particle and the continuous polymer phase. Alternatively, one or more such (e) additives may be present in (b) the binder material alone, or in both (b) the binder material and (a) the porous particles.

It will also be understood that while such (e) additives may be in the dry opaque layer, the same or different (e) additives may be present in the fabrics described above. Thus, any (e) additive may be present in the same or different amounts in multiple locations of the opaque article according to the present invention.

"inert" inorganic or organic fillers are particles that may be added to reduce the use of the more expensive (b) binder material. Such inert fillers do not undergo chemical reactions in the presence of water or other components in the aqueous formulation (described below); they also do not absorb electromagnetic radiation as do (c) opacifying colorants. Useful inert organic or inorganic filler materials include, but are not limited to, titanium dioxide, talc, clays (e.g., kaolin), magnesium hydroxide, aluminum hydroxide, dolomite, glass beads, silica, mica, glass fibers, nanofillers, calcium carbonate, and combinations thereof.

(e) The additive may be a surfactant, which is defined as a compound that lowers the surface tension in an aqueous formulated composition.

Useful biocides (i.e., antimicrobial or antifungal agents) that can be present as (e) additives include, but are not limited to, silver particles, platelets or fiber strands and silver-containing compounds, such as silver chelates and salts, such as silver sulfate, silver nitrate, silver chloride, silver bromide, silver iodide, silver iodate, silver bromate, silver tungstate, silver phosphate, and silver carboxylates. In addition, copper particles, flakes or fibers and copper-containing compounds, such as copper chelates and copper salts, may be present as (e) additives for biocidal purposes.

It may also be useful to include thickeners as (e) additives to modify the viscosity of the aqueous formulation and control its rheology.

Useful (e) additives may include one or more tinting colorants that may be used to provide a particular observable color, tint, or hue in the resulting dried opaque layer. These materials are not selected to provide the opacifying properties described below for (c) the opacifying colorant, and thus the tinting colorant is intended to be a different material with a different purpose.

Mixtures of different tinting colorants may be present. Specific tinting colorants can be used to obtain a desired tint or shade, which can be used in combination with the (c) opacifying colorants described below to offset or alter the original color of the opacifying element (without such materials) to provide greater whiteness (or brightness) in the final "color" (or tint). One or more tinting colorants may be incorporated into (a) the porous particles (within the volume of the discrete pores, within the continuous polymeric phase, or at both locations), or they may be uniformly dispersed within (b) the binder material. In some embodiments, a hueing colorant may be incorporated within the same (a) porous particle that also includes (c) an opacifying colorant. Alternatively, one or more tinting colorants may be present in both (a) the porous particles (where appropriate) and (b) the binder material.

In some embodiments, a first population (group) (a) of porous particles described herein comprises (c) an opaque colorant, and another population (group) (a) of porous particles comprising a hueing colorant described herein may be mixed with the first population (a) of porous particles. The two sets of porous particles may comprise the same or different polymers in the continuous polymer phase.

The one or more tinting colorants may be present in the dry opaque layer in an amount of at least 0.0001% and up to and including 3% by weight, based on the total weight of the dry opaque layer (including the residual aqueous medium). The hueing colorant may be a dye or organic pigment that is soluble or dispersible in the organic solvent and polymer used to prepare the (a) porous particles, and thus may be included in the oil phase used to prepare such (a) porous particles. Alternatively, the tinting colorant may be primarily a water-soluble or water-dispersible material included in the aqueous phase used to prepare (a) the porous particles.

It may also be useful to include one or more optical brighteners as (e) additives to increase the whiteness (brightness or "fluorescence" effect) of the final coloration of the back of the opaque article. Optical brighteners are sometimes referred to in the art as "fluorescent brighteners". Generally, such materials are organic compounds selected from known classes of compounds, such as derivatives of stilbene and 4, 4' -diaminostilbene (e.g. bis-triazinyl derivatives); derivatives of benzene and biphenyl (e.g., styril derivatives); a pyrazoline; derivatives of bis (benzoxazol-2-yl); coumarin; a quinolone; a naphthalimide; s-triazine and pyridotriazole. Specific examples of optical brighteners may be mentioned in the list including "Fluorescent Whitening Agents", Kirk-OthmerEncyclopedia of Chemical Technology, fourth editionVol.11, Wiley&Sons, 1994, among various publications. One or more such compounds may be present in an amount of at least 0.001 weight% and up to and including 0.5 weight%, based on the total weight of the dried opaque layer.

When present, one or more optical brighteners may be present in one or more materials in the dried opaque layer. For example, optical brighteners may be present in (b) the binder material. Alternatively, optical brighteners may be present: (a) within the continuous polymeric phase of the porous particles; (a) a first set (or any other set) of discrete pores in the porous particle; or (a) both the volume of the first set (or any other set) of discrete pores of the porous particle and the continuous polymer phase.

Aqueous formulations

The dry opacifying layers used in the present invention may be provided by corresponding aqueous formulations that can be prepared using the procedures described below.

The essential (a) and (b) components described above, as well as optional (c) opacifying colorant and (e) additive, are typically present in the (d) aqueous medium in amounts different from those defined above for drying the opacifying layer. However, the relative percentages (ratios) of the components should generally be the same as the amounts present in the dried opaque layer.

For example, the (a) porous particles (as described above) may be present in the aqueous formulation in an amount of at least 5 wt% and up to and including 50 wt%, or typically at least 20 wt% and up to and including 40 wt%, based on the total weight of the aqueous formulation.

The one or more (b) binder materials may be present in the aqueous formulation in an amount of at least 10 wt% and up to and including 50 wt%, or typically at least 15 wt% and up to and including 30 wt%, based on the total weight of the aqueous formulation.

The one or more (c) opacifying colorants (as described above) may be present in the aqueous formulation in an amount of at least 0.001 wt%, or at least 0.001 wt% and up to and including 0.5 wt%, or even in an amount of at least 0.003 wt% and up to and including 0.2 wt%, based on the total weight of the aqueous formulation, particularly when the opacifying colorant is carbon black.

The one or more (e) additives (as described above) may be present in the aqueous formulation in an amount of at least 0.0001 wt.% and up to and including 30 wt.%, or typically at least 0.001 wt.% and up to and including 20 wt.%, based on the total weight of the aqueous formulation.

Water is the predominant solvent used in the (d) aqueous medium in the aqueous formulation. By "predominantly" is meant that, of the total weight of solvent in the (d) aqueous medium, water constitutes at least 75% by weight, and more likely at least 80% by weight and up to and including 100% by weight, of the total weight of solvent. Auxiliary solvents that may be present must not adversely affect or harm other components in the aqueous formulation. Such auxiliary solvents may be water-miscible organic solvents, such as alcohols and ketones.

The aqueous medium may comprise at least 30 wt% and up to and including 70 wt%, or typically at least 40 wt% and up to and including 60 wt% of the total weight of the aqueous formulation.

All of the (a), (b), (c) and (e) components may be suitably mixed in the aqueous medium by dispersion using a cowles blade. Representative time and temperature conditions for preparing such aqueous formulations will be readily apparent to those skilled in the art.

Production of opaque elements

Opaque elements may be prepared according to the present invention by applying the aqueous formulation described above to one or both of the first and second opposing surfaces of a substrate (described above) in a suitable manner and with a suitable application device. If the aqueous formulation is applied to only one opposing surface, that opposing surface is defined as a "first opposing surface" and the other opposing surface is defined as a "second opposing surface". As illustrated in fig. 1A and 1B, the dry opaque layer on the first opposing surface may be disposed in contact with the back side of the fabric. Alternatively, as illustrated in fig. 2A and 2B, a dry opaque layer on the second, opposite surface of the substrate may be disposed in contact with the back surface of the fabric. As mentioned above, the aqueous formulation is not intentionally foamed prior to its application to the substrate.

In some embodiments, the same or different aqueous formulations may be applied to both the first and second opposing surfaces of the substrate.

The aqueous formulation may be disposed on the opposing surface in any suitable manner. For example, the opposing surfaces of the substrate may be coated with the aqueous formulation using suitable known coating equipment (floating knife, hopper, knife or gap coater) and coating procedures including, but not limited to, knife coating, gap coating (e.g., "knife over roll" and "knife over table" operations), floating knife, slot die coating, or slide hopper coating, particularly when multiple layers are applied to the substrate in the same operation. Thus, the aqueous formulation may be disposed directly onto the opposing surface of the substrate, wherein "directly" means without an intervening layer or layers; or it may be disposed indirectly to the substrate, meaning that some type of interlayer (primer layer or adhesion layer) is present.

Once the aqueous formulation has been disposed on the opposite surface of the substrate, it may be dried to remove most or all of the (d) aqueous medium present. Drying may be achieved by any suitable means, for example by heating with warm or hot air, microwave or IR radiation at a temperature and time sufficient to dry (for example at least 160 ℃) to provide a dry opaque layer.

Since the aqueous formulation is not intentionally "foamed" prior to its application to the substrate, it is not necessary to densify or crush the applied and dried opacifying layer.

Optional curing of (b) the binder material may be accomplished after drying by heat or radiation or other conditions under which (b) the binder material and any catalyst respond to crosslinking. In some embodiments, a suitable functionalized self-crosslinking latex composition is used as (b) the binder material. During this operation, a curing or crosslinking reaction may occur between the reactive pendant groups of the appropriate curable polymer chains. If the (b) binder material selected is not itself thermally reactive, a suitable catalyst and curing (crosslinking) agent may be added to the aqueous formulation to promote curing or crosslinking.

In addition, each dry opaque element can be designed to exhibit an L ("brightness") of at least 60, or more likely at least 75, or even at least 90, as determined using the procedure described below.

It is also possible to print an image on the outer surface of the opaque element after drying or curing using any suitable printing means, such as inkjet printing or flexography, to form a printed image of text, pictures, symbols or a combination thereof. Such printed images may be visible or they may be invisible to the naked eye (e.g., using fluorescent dyes in the printed images). Alternatively, the outer surface may be covered with a colorless layer by suitable means to provide the desired protective finish. In many cases, for example, an image formed on one outer surface in this manner is not visible or discernible from the other outer surface of the opaque element.

A thermally printed image can be formed on the outer surface from one or more thermal donor elements comprising a dye donor layer comprising one or more dye-sublimation printable colorants, for example, by using a thermal (sublimable) dye transfer printing process (with or without heat and pressure). For example, a thermal colorant image may be obtained using one or more thermal dye patches (with or without thermal colorless (transparent) patches). Useful details of such methods are provided in co-pending and commonly assigned U.S. serial No. 15/590,342 (filed by Nair and Herrick on 2017, 5, 9), the disclosure of which is incorporated herein by reference.

Preparation of opaque articles

Suitable fabrics as described above may be obtained or provided for use in making opaque articles according to the present invention. In addition, suitable opaque elements are prepared or obtained as described above. The opaque element and the fabric may be brought together in any suitable manner, such as by lamination, so that the dry opaque layer is disposed in contact with the back side of the fabric. These features are illustrated in fig. 1A and 1B.

Alternatively, as illustrated in fig. 2A and 2B, the second opposing surface of the opaque element may be arranged to contact the back surface of the textile.

In still further embodiments, as shown in fig. 3A and 3B, both opposing surfaces of the opaque elements have dry opaque layers disposed thereon, and either dry opaque layer may be disposed in contact with the back side of the fabric.

One suitable technique in which the opaque elements may be placed in contact with the back of the fabric is through the use of an adhesive material, such as a thin intermediate heat or cold seal adhesive material, for example, as illustrated in fig. 4A and 4B. In some embodiments, a binder material is incorporated into the dried opaque layer along with (a) the porous particles, (b) the binder material, and optionally (c) the opaque colorant and (e) the additive. The outer surface of the dry opaque layer may be laminated to the backside of the fabric.

When a heat seal adhesive is used, the opaque element may be supplied from a suitable source (e.g., a supply roll); a heat seal adhesive may be applied to the surface to be adhered; and then the opaque element and the web from a suitable source (e.g., a second supply roll) can be brought together. Alternatively or additionally, a heat seal adhesive may be supplied to the back of the web and the two materials brought together. In other embodiments, a heat seal adhesive may be applied to the two materials, which are then brought together. Alternatively, the heat seal adhesive may be supplied (sprayed or jetted) between the two materials as they are brought together. After heating, the heat seal adhesive is then allowed to cool, for example to room temperature, followed by lamination of the opaque element article and the fabric.

Suitable adhesive materials are known in the art and may include at least one polyamide, polyester, epoxy, acrylic, anhydride modified polyolefin, polyurethane, or blends of two or more types of polymers.

Other adhesive materials may be used in the present invention, including but not limited to the use of a layer of any cold seal or pressure sensitive, light sensitive or heat sensitive adhesive precursor material, which is then "activated" using pressure, light exposure or heat exposure, respectively, to create an adhesive layer. For example, liquid adhesives including plastisols, epoxies, acrylics, organosols, and urethane adhesives may be used, which may be applied to the opaque element or fabric with suitable coating techniques (gravure cylinder, knife, roller, reverse roller, or anilox roller) under heat, followed by cooling to ensure adhesive bonding.

It is also possible to laminate the opaque element and the fabric without the use of an intermediate adhesive layer. This can be accomplished in any suitable manner known in the art using mechanical means rather than adhesive means, such as direct calendar lamination, to form a mechanical bond between the two elements. In direct calender lamination, the two materials are brought together, for example under heat from a suitable source (e.g., separate supply rolls), and fed together into a pressure roll or a combination of a calender roll and an embossing roll to form a mechanical bond upon cooling. The resulting opaque article can then be wound into a roll or otherwise stored or used immediately in a finishing operation.

Either or both outer surfaces of the opaque element may be flocked to provide an attractive finish (surface finish). In general, what is surface finished in this manner may be the opposite surface that is not in contact with the back side of the fabric. The dry opaque layer may also be flocked. Flock refers to very short (0.1 mm and up to several millimeters) fibers, which can be provided using known electrostatic or mechanical techniques. Such surfaces then become "flocked surfaces".

Alternatively or additionally, the opposite surface of the opaque element not having the dry opaque layer disposed thereon may be modified with embossing or printing using known procedures to provide a suitable image or pattern.

It may also be desirable to incorporate the dried functional composition onto the dried opaque layer or the opposing surface without the dried opaque layer. The functional composition may have any of the following: (i) inorganic or organic spacer particles having a mode particle size of 1 to 100 μm; (ii) a solid lubricant; and (iii) a toning material. Details on such functional compositions and how they may be used are provided in U.S. serial No. 16/018,367 (filed by Nair, Lobo, and Donovan on 26.6.2018).

Opaque articles provided by the present invention can have an optical density (as determined as described below) of at least 3, or even at least 4, or at least 5.

Additionally, the opaque article may further comprise an antimicrobial agent, a flame retardant, or both types of materials, examples of which are described above for drying the opaque layer.

Additionally, the opaque article may further comprise a surface finish selected from the group consisting of: flock, lubricants, antiblocking agents, antistatic agents, tactile modifiers, visual modifiers and anti-soiling agents. Examples of such materials and amounts to be used are known in the textile art.

The present invention provides at least the following embodiments and combinations thereof, but as the skilled person will appreciate from the teachings of the present disclosure, other combinations of features are considered to be within the scope of the present invention:

1. an opaque article, comprising:

(i) a fabric having a front side and a back side; and

(ii) an opaque element laminated to the backside of the fabric, the opaque element comprising: a substrate having a first opposing surface and a second opposing surface; and a dry opaque layer having an inner surface and an outer surface, the dry opaque layer being disposed such that its inner surface is in contact with a first opposing surface of the substrate,

the dry opaque layer comprises:

(a) at least 40% and up to and including 90% by weight of porous particles, each porous particle comprising a continuous polymer phase and discrete pores dispersed within the continuous polymer phase, the porous particles having a mode particle size of at least 2 μm and up to and including 50 μm and a porosity of at least 20% and up to and including 70% by volume; and

(b) at least 10% and up to and including 60% by weight of binder material,

(a) the total amount of porous particles and (b) binder material is based on the total weight of the dried opaque layer.

2. The opaque article of embodiment 1, having an optical density of at least 3, and the opaque elements have an L of at least 60.

3. The opaque article of embodiment 1 or 2, having an optical density of at least 3, and the opaque elements have L of at least 70.

4. The opaque article of any of embodiments 1 to 3, wherein the dried opaque layer further comprises at least 0.001 wt.%, based on the total dry weight of the dried opaque layer, (c) an opaque colorant capable of absorbing electromagnetic radiation having a wavelength of at least 380 nm and up to and including 800 nm.

5. The opaque article of embodiment 4, wherein (c) the opacifying colorant is present in an amount of at least 0.001 weight% and up to and including 0.3 weight%, based on the total weight of the dried opaque layer.

6. The opaque article of embodiment 4 or 5, wherein (c) the opaque colorant is carbon black, a neutral black pigment or dye other than carbon black, or a combination of two or more such materials.

7. The opaque article of any of embodiments 4 to 6, wherein (c) the opacifying colorant is present within (a) the porous particles.

8. The opaque article of any of embodiments 1 to 7, wherein the outer surface of the dry opaque layer is laminated to the back of the fabric.

9. The opaque article of any of embodiments 1 to 7, wherein the second opposing surface of the substrate is laminated to the back side of the fabric.

10. The opaque article of any of embodiments 1 to 9, further comprising a second dry opaque layer disposed on a second opposing surface of the substrate.

11. The opaque article of any of embodiments 1 to 10, further comprising an adhesive material disposed between (i) the fabric and (ii) the opaque element.

12. The opaque article of any of embodiments 1 to 11, further comprising an adhesive material within the dried opaque layer.

13. The opaque article of embodiment 11 or 12, wherein the adhesive material is a heat seal adhesive or a cold seal adhesive.

14. The opaque article of any of embodiments 11 to 13, wherein the adhesive material comprises a material selected from the group consisting of: polyamides, polyurethanes, epoxies, polyesters, acrylics, anhydride modified polyolefins, and blends thereof.

15. The opaque article of any of embodiments 1 to 14, further comprising an antimicrobial agent, a flame retardant agent, or both an antimicrobial agent and a flame retardant agent.

16. The opaque article of any of embodiments 1 to 15, wherein the substrate comprises a polymeric material selected from the group consisting of: polyesters, cellulosic materials, acyclic polyolefins, cyclic olefin polymers, polyamides, ethylene vinyl acetate, polyvinyl chloride, polyvinylidene chloride, and blends thereof.

17. The opaque article of any of embodiments 1 to 16, wherein the substrate comprises one or more polymeric films.

18. The opaque article of any of embodiments 1 to 17, wherein (a) the porous particles have a mode particle size of at least 3 μ ι η and up to and including 20 μ ι η.

19. The opaque article of any of embodiments 1 to 18, wherein the dry opaque layer further comprises one or more (e) additives selected from the group consisting of: dispersants, plasticizers, flame retardants, optical brighteners, thickeners, biocides, tinting colorants, inert inorganic or organic fillers, and combinations of any of these materials.

20. The opaque article of embodiment 19, wherein the dry opaque layer further comprises one or more (e) additives comprising silver particles or silver salts.

21. The opaque article of any of embodiments 1 to 20, wherein (b) the binder material has a glass transition temperature (T) of less than 25 ℃_g)。

22. The opaque article of any of embodiments 1 to 21, wherein the dry weight ratio of (a) the porous particles to (b) the binder material in the dry opaque layer is at least 2:3 and up to and including 9: 1.

23. The opaque article of any of embodiments 1 to 22, wherein the dry coverage of the dry opaque layer is at least 50 g/cm²And up to and including 1000 g/cm²。

24. The opaque article of any of embodiments 1 to 23, wherein (a) the porous particles have a mode particle size of at least 3 μ ι η and up to and including 20 μ ι η and a porosity of at least 20% and up to and including 65%; and carbon black is present as (c) an opacifying colorant in the discrete pores of the (a) porous particles in an amount of at least 0.003 weight% and up to and including 0.3 weight%, based on the total weight of the dried opacifying layer.

25. The opaque article of any of embodiments 1 to 24, further comprising a surface finish selected from the group consisting of: flock, lubricants, antiblocking agents, antistatic agents, tactile modifiers, visual modifiers and anti-soiling agents.

26. A method of providing an opaque article according to any of embodiments 1 to 25, comprising:

A) providing (i) a fabric having a front side and a back side;

B) providing (ii) an opaque element comprising: a substrate having a first opposing surface and a second opposing surface; and a dry opaque layer having an inner surface and an outer surface, the dry opaque layer being disposed such that its inner surface is in contact with a first opposing surface of the substrate, an

C) (iii) laminating (ii) an opacifying element to the back of the fabric to provide an opaque article.

27. The method of embodiment 26 comprising C) laminating the outer surface of the dried opaque layer of the opaque element to the back side of the fabric.

28. The method of embodiment 26 comprising C) laminating a second opposing surface of the substrate to the backside of the fabric.

29. The method of any of embodiments 26 through 28 wherein the opacifying element comprises a second dry opacifying layer disposed on a second, opposite surface of the substrate.

30. The method of any of embodiments 26, 27 and 29, wherein an adhesive material is included in the dry opaque layer and the outer surface of the dry opaque layer is laminated to the back surface of the fabric.

31. The method of any one of embodiments 26, 27 and 29 comprising C) laminating the opaque element to the back side of the fabric using a mechanical method without an adhesive material.

32. The method of any of embodiments 26 through 31 wherein the fabric comprises a material that has been treated to provide water repellency and stain resistance prior to C) lamination.

33. The method of any of embodiments 26 through 32 wherein C) laminating is performed by direct calendar lamination.

29. The method of any one of embodiments 26 to 33, wherein the opaque elements have a dry thickness of at least 100 μm.

The following examples are provided to illustrate the practice of the invention and are not intended to be limiting in any way.

The following materials were prepared or purchased as indicated and used in the following examples:

NEOCRYL^®a-6093: acrylic, elastomeric emulsions, useful as adhesive polymers, obtained from DSM;

TERGITOL^®15-S-7 surfactant (Dow Chemical Company): secondary alcohol surfactant with HLB value of 12.4, obtained from Dow Chemical Corp.；

The white woven fabric material used as the "fabric" in the opaque article was a woven poplin having a thickness of 0.0076 inches (0.02 cm).

The substrate used to produce the opaque element was a polyethylene terephthalate film having a thickness of 0.0005 inches (0.0127 mm).

(a) Preparation of porous particles:

the following describes (a) porous particles used to prepare opaque elements and opaque articles for each inventive example along with the characteristics of the particles. All (a) porous particles contain 1% by weight of the optical brightener in the continuous polymer phase.

Porous particles PX containing 0.1 wt% of (c) opacifying colorant (carbon black) in discrete pores and cellulose acetate butyrate in the continuous polymer phase were prepared as described in U.S. patent 9,963,569(Nair et al). The resulting (c) porous particles had a particle size of 5 μm and a porosity of 43%.

Porous particles PY containing 0.05% by weight of (c) opacifying colorant (carbon black) in discrete pores and cellulose acetate butyrate in the continuous polymer phase were prepared as described in us patent 9,963,569 (mentioned above). The resulting (a) porous particles had a particle size of 5.7 μm and a porosity of 49.5%.

Measurement:

the mode particle size of the porous particles of (a) was measured using a Sysmex FPIA-3000 flow particle image analyser available from Malvern Panalytical. Light scattering is used to determine the particle size of the dispersed pigment.

The porosity of the (a) porous particles was measured using a modified version of the known mercury intrusion porosimetry.

The ability of each opaque article in the examples to block light in transmitted light was evaluated by measuring its Optical Density (OD) using a custom-made instrument consisting of a fiber-optic xenon light source, a computer-controlled conversion platform (translational stage), and a spectrophotometer. The optical fiber was positioned 10 mm above the surface of the opaque element. A photodetector is placed on the other side of each opaque article directly below the optical fiber to quantify the amount of light passing through the opaque article. The Optical Density (OD) of each opaque article is calculated by comparing the light passing through the opaque article to the light reaching the detector in the absence of the opaque article.

The light reflectance (or brightness) of each opacifying element (the dry opacifying layer or substrate side of the opacifying element) was determined by first measuring the spectral reflectance in the 400-700 nm wavelength range using a Hunter Labs UltraScan XE colorimeter equipped with an integrating sphere and a pulsed xenon light source and appropriate filters for a standard D65 light source, with the opacifying element (the dry opacifying layer or substrate side of the opacifying element) facing the light source. The percent reflectance range of 0 to 100% was fixed using light traps and standard white tiles. The X, Y and Z tristimulus values for each opaque element were also determined and used in conjunction with the CIELab color space to calculate specific values for the lightness (L), red-green characteristic (a), and yellow-blue characteristic (b) of each opaque element. The Y tristimulus value is used as a measure of the light reflectivity or brightness of each opaque element.

Inventive examples 1a and 1 b:

by mixing 19.4 wt% of NEOCRYL^®A-6093 adhesive Polymer, 0.9% by weight of TERGITOL^®15-S-7 surfactant, water, and 29.4 wt% porous particles PX (with 0.1% carbon black in discrete pores) were combined in a vessel to prepare an aqueous composition. The aqueous formulation was mixed using a Cowles blade until all the porous particles were well dispersed and then degassed to remove large bubbles so that no foam was present in the formulation. The resulting mixed aqueous composition was coated onto a substrate (described above) using a doctor blade having a 0.024 inch (0.61 mm) gap and dried at 35 ℃ to form a dry opaque layer on the laminate. The dry opaque layer has a density of 201 g/m²(5.9 oz/yd²) Total dry coverage and 0.06 wt% carbon black. The resulting opaque element laminate was laminated to the back of a white woven fabric having a thickness of 0.0076 inches (0.02 cm) (with the dry opaque layer in contact with the fabric back) to form an opaque article according to the invention (invention example 1 a).

A second opposing surface of a sample of the same opacifying element was also laminated to the back of the white woven fabric (with the dry opacifying layer facing away from the fabric) to form another opaque article according to the invention (invention example 1 b).

For both examples, lamination was performed using a double-sided pressure sensitive, optically clear 2 mil (0.05 mm) adhesive film with a release liner on both sides. The adhesive film is first applied to the opaque elements and then to the back of the fabric.

Inventive examples 2a and 2 b:

inventive example 2 was prepared in the same manner as inventive example 1a, except that the porous particles PY containing 0.05% of carbon black in the discrete pores were used. The aqueous composition was coated and dried in the same manner as in inventive example 1 a. The final dry opaque layer in the opaque element had a density of 201 g/m²Total dry coverage and 0.03 wt% carbon black. The opacifying elements were laminated (with the dry opacifying layer in contact with the back of the white woven fabric) to form an opaque article according to the invention (invention example 2 a).

A portion of the opaque article is also flocked by: adhesive was applied to the opposite surface of the opaque element to the fabric and then 0.1 mm cotton lint was applied to the adhesive with a hand held screen. The flocked surface had a textile-like feel compared to an unflanted sample of the same opaque article.

Inventive example 3:

inventive example 3 was prepared in the same manner as inventive example 1a, except that an 50/50 wt% mixture of porous particles PX and PY was used. The aqueous composition was coated and dried in the same manner as in inventive example 1 a. The dried opaque layer contained 201 g/m²Total dry coverage and 0.04 wt% carbon black. The resulting opaque element was laminated to the back of a white woven fabric with the dry opaque layer in contact with the back of the fabric.

The optical density of the various opaque articles and the chromaticity data of the opaque elements are shown in table I, where all parameters are as described above. The data for the individual fabrics are also shown in table I below.

TABLE I

NA = inapplicable

The examples and data in table I show that opaque articles can be prepared by laminating opaque elements containing porous particles onto fabrics according to the present invention, and that all opaque articles exhibit good light blocking with an optical density >4 compared to the fabric alone. The values of L, a and b describe the properties of the surface of the opaque elements in the various embodiments, e.g. the exposed surface of the dried opaque layer, or the substrate side of the opaque elements, or the flocked surface of the opaque elements. Although the opaque element has a high opacity, it exhibits a value of L > 70. They also exhibit a high degree of whiteness as indicated by the Y tristimulus values of light reflectance greater than 45.

Parts list

10 Fabric

15 back side

20 front surface

25 opaque element

30 base material

35 first opposite surface

40 second opposing surface

45 drying the opaque layer

46 outer surface

47 inner surface

50 opaque article

55 opaque element

60 second opposing surface

65 first opposite surface

70 opaque article

75 opaque element

80 second opposing surface

85 second dry opaque layer

86 inner surface

87 outer surface

90 opaque article

100 Fabric

110 back side

115 front side

120 adhesive material

125 opaque article