阅读说明：本技术 高灵敏度可逆变色织物及其制备方法和应用 (High-sensitivity reversible color-changing fabric and preparation method and application thereof ) 是由 王雯雯 王栋 郑玉竹 严忠 卢静 于 2021-01-07 设计创作，主要内容包括：本发明提供了一种高灵敏度可逆变色织物及其制备方法和应用。根据织物的预设织物孔径大小,制备含有变色基团化合物的功能化乳液,使得功能化乳液的乳胶粒子的粒径为所述预设织物孔径的0.001～0.1倍；然后将功能化乳液浸渍吸附或喷涂于待处理织物上,烘干,得到高灵敏度可逆变色织物。本发明基于织物疏松多孔结构,调控功能化乳液的组成和粒径,使得功能化乳液颗粒均匀的分散于所述织物多孔结构中,易于产生应力集中效应,从而显著提高变色织物的变色灵敏度,并提高耐洗牢度。本发明高灵敏度可逆变色织物可很好地应用于无墨书写、柔性显示器、柔性传感器、信息保密或防伪等方面。(The invention provides a high-sensitivity reversible color-changing fabric and a preparation method and application thereof. Preparing a functionalized emulsion containing a color-changing group compound according to the preset fabric aperture size of the fabric, so that the particle size of latex particles of the functionalized emulsion is 0.001-0.1 times of the preset fabric aperture; and then dipping, adsorbing or spraying the functional emulsion on the fabric to be treated, and drying to obtain the high-sensitivity reversible color-changing fabric. According to the invention, the composition and the particle size of the functional emulsion are regulated and controlled based on the loose porous structure of the fabric, so that the particles of the functional emulsion are uniformly dispersed in the porous structure of the fabric, and the stress concentration effect is easy to generate, thereby obviously improving the color change sensitivity of the color-changing fabric and improving the washing fastness. The high-sensitivity reversible color-changing fabric can be well applied to the aspects of inkless writing, flexible displays, flexible sensors, information confidentiality or anti-counterfeiting and the like.)

1. A preparation method of a high-sensitivity reversible color-changing fabric is characterized by comprising the following steps:

s1, preparing or selecting a fabric with a preset fabric weave structure and a preset fabric aperture as a fabric to be treated;

s2, preparing a functionalized emulsion containing a color-changing group compound according to the preset fabric aperture size of the fabric, wherein the particle size of latex particles of the functionalized emulsion is 0.001-0.1 time of the preset fabric aperture size;

and S3, dipping, adsorbing or spraying the functional emulsion on the fabric to be treated, and then drying to obtain the high-sensitivity reversible color-changing fabric.

2. The method for preparing the high-sensitivity reversible color-changing fabric according to claim 1, wherein in step S1, the preset fabric aperture is 0.5-500 μm.

3. The method for preparing the high-sensitivity reversible color-changing fabric according to claim 1, wherein in step S1, the predetermined fabric weave structure includes but is not limited to plain, twill or satin; the material of the fabric to be treated includes but is not limited to pure cotton fabric, polyester-cotton blended fabric or cotton and spandex blended fabric.

4. The method for preparing high-sensitivity reversible color-changing fabric according to claim 1, wherein in step S2, the color-changing group compound includes but is not limited to one or more of photochromic material, force-sensitive photochromic material.

5. The method for preparing the high-sensitivity reversible color-changing fabric according to claim 4, wherein the color-changing group compound includes but is not limited to one or more of spiropyran compounds and rhodamine compounds.

6. The method for preparing the high-sensitivity reversible color-changing fabric according to claim 4 or 5, wherein the functionalized emulsion contains a latex inter-particle cross-linking agent, and the color-changing group compound functions as a latex intra-particle cross-linking agent in the functionalized emulsion.

7. The method for preparing the high-sensitivity reversible color-changing fabric according to claim 1 or 6, wherein the functionalized emulsion comprises the following components in parts by weight: 30-60 parts of methyl methacrylate, 40-80 parts of butyl acrylate, 3-10 parts of hydroxyethyl methacrylate, 0-30 parts of an inter-latex particle cross-linking agent, 1-10 parts of a compound containing a color-changing group, 1-3 parts of an initiator, 0.5-5 parts of an emulsifier, 0.3-2 parts of a neutralizer and 150-300 parts of deionized water.

8. The method for preparing the high-sensitivity reversible color-changing fabric according to claim 1, wherein in step S3, the adsorption amount of the functionalized emulsion is 10-80% of the fabric mass.

9. A high-sensitivity reversible color-changing fabric, which is prepared by the preparation method of any one of claims 1 to 8.

10. Use of the high-sensitivity reversible color-changing fabric prepared by the preparation method according to any one of claims 1 to 8 or the high-sensitivity reversible color-changing fabric according to claim 9, wherein the high-sensitivity reversible color-changing fabric is used for inkless writing, flexible displays, flexible sensors, information security or anti-counterfeiting.

Technical Field

The invention relates to the technical field of functional textile materials, in particular to a high-sensitivity reversible color-changing fabric and a preparation method and application thereof.

Background

With the increasing maturity of the traditional textile industry, the research of the textile industry is developed towards multifunctionality and intelligence, and the intelligent fabric is prepared by combining the fabric and various intelligent materials, so that the functions of the traditional fabric can be expanded, and the additional value of the traditional fabric can be improved. The intelligent fabric has functions which are not possessed by the traditional fabric, can sense external mechanical force, light, heat, chemical or other condition stimulation and make specific response to the external stimulation, such as color change, temperature adjustment, antibiosis and the like. The color-changing fabric is used as a novel functional fabric, and has great application potential in the fields of flexible display, sensing, military camouflage, anti-counterfeiting and the like, and the color is changed according to the change of temperature, the change of light, the dry and wet condition or the stress condition so as to play the functions of reminding, warning or anti-counterfeiting.

At present, a discoloration coating is prepared on the surface of a fabric by a dipping adsorption or coating method. For example, patent CN205112565U discloses a stretch color-changing fabric, wherein a stretch color-changing film layer composed of polyurethane, polyacrylate or hydroxyl silicone is coated on an elastic substrate, so as to realize the color-changing function of the fabric when stretching. Patent CN108085996A discloses a photochromic microcapsule hybrid modified silica sol coated fabric, which is prepared by mixing hydrophobic modified silica sol and photochromic microcapsules to prepare a modified solution, and then finishing the modified solution on the fabric, wherein the fabric has a photochromic function while realizing a water repellent effect. Patent CN101817251A discloses a method for changing color of fabric, which comprises attaching a layer of color-changeable ink on the surface of the fabric fiber to change the color of the fabric according to the environmental conditions. Patent CN110578258A discloses a preparation process of photochromic polypropylene yarn fabric, which comprises preparing photochromic microcapsules by emulsion polymerization, and mixing the photochromic microcapsules with waterborne polyurethane and a thickening agent to obtain coating adhesive; fixing the polypropylene yarn fabric on a glass plate, coating the coating adhesive on the polypropylene fabric, and pre-drying and baking to obtain the photochromic polypropylene yarn fabric. However, the photochromic coating does not adaptively regulate and control the composition and the structure of the photochromic coating according to the specific tissue structure of the fabric so as to improve the color-changing sensitivity and prolong the service life. Therefore, the preparation method has limitations, the connectivity between the color-changing film layers is poor, the color-changing sensitivity and the color-changing stability of the prepared color-changing fabric are low, and the application range of the color-changing fabric is limited. For example, the force-sensitive color-changing fabric has lower color-changing sensitivity and stability, so that the lower limit value of pressure is higher, and the pressure detection range is reduced; the photochromic fabric can also affect the detection accuracy due to the unstable color change performance of the coating. Especially when used for inkless writing or information security, sensitivity and stability of discoloration are extremely important.

In view of the above, there is a need to design an improved method for preparing a reversible color-changing fabric with high sensitivity to solve the above problems.

Disclosure of Invention

The invention aims to provide a high-sensitivity reversible color-changing fabric and a preparation method and application thereof. Based on the loose porous structure of the fabric, the composition and the particle size of the functional emulsion are regulated and controlled, so that the particles of the functional emulsion are uniformly dispersed in the porous structure of the fabric, the stress concentration effect is generated, the color change sensitivity of the color-changing fabric is obviously improved, and the washing fastness is improved.

In order to realize the aim, the invention provides a preparation method of a high-sensitivity reversible color-changing fabric, which comprises the following steps:

s1, preparing or selecting a fabric with a preset fabric weave structure and a preset fabric aperture as a fabric to be treated;

s2, preparing a functionalized emulsion containing a color-changing group compound according to the preset fabric aperture size of the fabric, wherein the particle size of latex particles of the functionalized emulsion is 0.001-0.1 time of the preset fabric aperture size;

and S3, dipping, adsorbing or spraying the functional emulsion on the fabric to be treated, and then drying to obtain the high-sensitivity reversible color-changing fabric.

As a further improvement of the invention, in step S1, the preset fabric aperture is 0.5-500 μm.

As a further improvement of the present invention, in step S1, the predetermined weave structure includes, but is not limited to, plain, twill or satin; the material of the fabric to be treated includes but is not limited to pure cotton fabric, polyester-cotton blended fabric or cotton and spandex blended fabric.

As a further improvement of the present invention, in step S2, the color-changing group compound includes, but is not limited to, one or more of a photochromic material, a force-sensitive photochromic material.

As a further improvement of the invention, the color-changing group compound comprises but is not limited to one or more of spiropyran compounds and rhodamine compounds.

As a further improvement of the invention, the functionalized emulsion comprises an inter-latex particle cross-linking agent, and the color-changing group compound functions as an intra-latex particle cross-linking agent in the functionalized emulsion.

As a further improvement of the invention, the functionalized emulsion comprises the following components in parts by weight: 30-60 parts of methyl methacrylate, 40-80 parts of butyl acrylate, 3-10 parts of hydroxyethyl methacrylate, 0-30 parts of an inter-latex particle cross-linking agent, 1-10 parts of a compound containing a color-changing group, 1-3 parts of an initiator, 0.5-5 parts of an emulsifier, 0.3-2 parts of a neutralizer and 150-300 parts of deionized water.

As a further improvement of the present invention, in step S3, the adsorption amount of the functionalized emulsion is 10% to 80% of the mass of the fabric.

The high-sensitivity reversible color-changing fabric is prepared by the preparation method.

The high-sensitivity reversible color-changing fabric prepared by the preparation method or the application of the high-sensitivity reversible color-changing fabric is applied to inkless writing, flexible displays, flexible sensors, information confidentiality or anti-counterfeiting.

The invention has the beneficial effects that:

1. according to the preparation method of the high-sensitivity reversible color-changing fabric, the composition and the particle size of the functional emulsion are regulated and controlled based on the loose porous structure of the fabric, so that the particles of the functional emulsion are uniformly dispersed in the porous structure of the fabric, and the color-changing coating is modified, so that the optimal matching relationship between the fabric structure and the color-changing coating structure is obtained. Under the optimal matching relationship, the prepared color-changing fabric has optimal comprehensive performance and higher universality, and an effective way is provided for the preparation of the color-changing fabric coating.

2. According to the preparation method of the high-sensitivity reversible color-changing fabric, the porous plain fabric is preferably selected, more latex particles can be contained, the weave structure is absolutely and symmetrically distributed, and the prepared color-changing coating is better in distribution uniformity, so that the sensitivity and the stability of color-changing response are higher. In addition, the color-changing coating formed in the porous structure can generate a stress concentration effect (the interface of the emulsion particles and the fibers is a stress concentration point), when the color-changing coating is used for force-sensitive color changing, the lower limit value of color-changing pressure is obviously reduced, the stressed color-changing area is concentrated, when a pressure in a fine range is applied, the color can be developed in the stressed area in a concentrated mode, the spread area is small, and therefore the color-changing coating can be well applied to inkless writing and can display writing information more accurately. When used for other stimuli responses, such as photochromic, can also help to display written information more accurately when "inkless" with an ultraviolet pen due to high dispersion uniformity and stability of the color changing coating and stress concentration effects. The accuracy and the copying difficulty of applying the anti-counterfeiting code to anti-counterfeiting and information confidentiality are higher.

3. According to the preparation method of the high-sensitivity reversible color-changing fabric, the functionalized emulsion contains the cross-linking agent between the latex particles, and the color-changing group compound plays a role of the cross-linking agent in the latex particles in the functionalized emulsion. The color-changing group compound is used as an internal latex particle crosslinking agent to form monodisperse latex particles with the coating monomer through emulsion polymerization, and the cross-linking agent between the latex particles is used for enhancing the adhesion and the strength of the color-changing coating layer when the functionalized emulsion is treated on a fabric. The color-changing group compound is used as a cross-linking agent in latex particles, so that the color-changing sensitivity of the color-changing coating formed in such a way is higher.

Drawings

FIG. 1 is a schematic structural diagram of a high-sensitivity reversible color-changing fabric prepared by the invention.

In fig. 2, a, b and c are respectively a plain weave, a twill weave and a satin weave structure schematic diagram.

In fig. 3, a, b and c are digital photographs of the pure cotton color-changing fabric prepared in example 1 before being subjected to pressure, after being subjected to pressure and after being subjected to color fading by white light irradiation, respectively.

In FIG. 4, a, b and c are photographs of the pure cotton color-changing fabric prepared in example 1 before light irradiation, after "inkless writing" using an ultraviolet pen having a wavelength of 365nm, and after color fading, respectively.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in detail below with reference to specific embodiments.

It should be noted that, in order to avoid obscuring the present invention with unnecessary details, only the structures and/or processing steps closely related to the scheme of the present invention are shown in the specific embodiments, and other details not closely related to the present invention are omitted.

In addition, it is also to be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

The invention provides a preparation method of a high-sensitivity reversible color-changing fabric, which comprises the following steps:

s1, preparing or selecting a fabric with a preset fabric weave structure and a preset fabric aperture as a fabric to be treated.

In step S1, the predetermined fabric has a pore size of 0.5 to 500 μm, preferably 0.5 to 100 μm, and more preferably 10 to 50 μm. The fabric is obtained by interweaving warp and weft yarns according to a certain rule to form certain grains and patterns on the surface of the fabric, and the warp and weft yarns are interwoven or float and sink to enable the fabric to have a porous network structure which is mutually penetrated. The aperture of the fabric can be regulated and controlled by adjusting the fineness, the warp and weft density and the like of the yarns. According to the invention, the color-changing coating is modified based on the porous structure of the fabric, so that the optimal matching relationship between the fabric structure and the color-changing coating structure is obtained, the universality is high, and an effective way is provided for the preparation of the color-changing fabric coating.

Referring to fig. 1 and 2, the predetermined weave structure includes, but is not limited to, plain, twill or satin weave, preferably plain weave. Compared with twill and satin, the plain weave has more pore structures and can contain more latex particles; and the organization structures are distributed in absolute symmetry, and the prepared color-changing coating has better distribution uniformity, so that the sensitivity and the stability of color-changing response are higher. In addition, the color-changing coating formed in the porous structure can generate a stress concentration effect, when the color-changing coating is used for force-sensitive color changing, the lower limit value of color-changing pressure is obviously reduced, the stressed color-changing area is concentrated, when a pressure in a small range is applied, the color can be concentrated in the stressed area for color development, and the spread area is small, so that the color-changing coating can be well applied to inkless writing and can display written information more accurately. When used for other stimuli responses, such as photochromic, can also help to display written information more accurately when "inkless" with an ultraviolet pen due to high dispersion uniformity and stability of the color changing coating and stress concentration effects. The accuracy and the copying difficulty of the anti-counterfeiting and information confidentiality application are higher.

The material of the fabric to be treated includes but is not limited to pure cotton fabric, polyester-cotton blended fabric or cotton and spandex blended fabric. The fabric surface contains more active groups such as hydroxyl and carboxyl, which is helpful for improving the washing fastness of the color-changing coating.

Preferably, in step S1, the fabric to be treated is washed with sodium lauryl sulfate and then dried. The treatment helps to remove impurities on the surface of the fabric, improves the reactivity of the surface groups of the fabric, improves the dispersion uniformity of the color-changing coating on the fabric, and further improves the stability of the color-changing coating.

S2, preparing a functionalized emulsion containing a color-changing group compound according to the preset fabric aperture size of the fabric, wherein the particle size of latex particles of the functionalized emulsion is 0.001-0.1 times of the preset fabric aperture, and preferably 0.01-0.05 times of the preset fabric aperture. Experiments of the invention show that the prepared color-changing fabric has the optimal comprehensive performance under the conditions of the aperture of the fabric and the particle size of latex particles.

In step S2, the color-changing group compound includes, but is not limited to, one or more of a photochromic material, a force-sensitive photochromic material. The color-changing group compound preferably comprises a spiropyran-based compound.

The functionalized emulsion contains a cross-linking agent between latex particles, and the color-changing group compound plays the role of a cross-linking agent in the latex particles in the functionalized emulsion. The color-changing group compound is used as an internal crosslinking agent of the latex particles, and forms monodisperse latex particles with the coating monomer through emulsion polymerization, and the crosslinking agent among the latex particles is used for enhancing the adhesion and the strength of the color-changing coating through the crosslinking agent among the latex particles when the functionalized emulsion is treated on a fabric.

In some embodiments, the functionalized emulsion comprises, in parts by weight: 30-60 parts of methyl methacrylate, 40-80 parts of butyl acrylate, 3-10 parts of hydroxyethyl methacrylate, 0-30 parts of an inter-latex particle cross-linking agent, 1-10 parts of a spiropyran compound (an internal latex particle cross-linking agent), 1-3 parts of an initiator, 0.5-5 parts of an emulsifier, 0.3-2 parts of a neutralizer and 150-300 parts of deionized water. The spiropyran compound at least comprises two olefin double bonds so as to play a role of a cross-linking agent in the latex particles.

The cross-linking agent between the latex particles is selected from one or more of Vinyl Triethoxysilane (VTES), 3-methacryloxypropyl Trimethoxysilane (TMSPMA), vinyl trimethoxysilane and vinyl triisopropoxy silane, the initiator is selected from one or more of potassium persulfate (KPS) and Ammonium Persulfate (APS), the emulsifier is selected from one or more of Sodium Dodecyl Benzene Sulfonate (SDBS) and Sodium Dodecyl Sulfate (SDS), and the neutralizer is selected from sodium bicarbonate and Phosphate Buffered Saline (PBS).

And S3, dipping, adsorbing or spraying the functional emulsion on the fabric to be treated, and then pre-drying and baking to obtain the high-sensitivity reversible color-changing fabric.

In step S3, the functionalized emulsion has an adsorption capacity of 10% to 80% of the mass of the fabric. Respectively recording the mass M of the original cloth₀Mass after adsorption M₁And (M) is calculated as the amount of adsorption₁～M₀)/M₀×100％。

Preferably, the functionalized emulsion is uniformly mixed with a bayer 2748 curing agent in a ratio of 1:1.4 and then treated onto a fabric.

The high-sensitivity reversible color-changing fabric prepared by the preparation method or the application of the high-sensitivity reversible color-changing fabric is applied to inkless writing, flexible displays, flexible sensors, information confidentiality or anti-counterfeiting. The color-changing coating formed in the porous structure of the fabric can generate a stress concentration effect based on the porous structure of the fabric, when the color-changing coating is used for force-sensitive color changing, the lower limit value of color-changing pressure is obviously reduced, the stressed color-changing area is concentrated, when a pressure in a small range is applied, the color can be developed in the stressed area in a concentrated manner, and the spread area is small, so that the color-changing coating can be well applied to inkless writing and can more accurately display writing information. When used for other stimuli responses, such as photochromic, can also help to display written information more accurately when "inkless" with an ultraviolet pen due to high dispersion uniformity and stability of the color changing coating and stress concentration effects. The accuracy and the copying difficulty of the anti-counterfeiting and information confidentiality application are higher.

Example 1

A high-sensitivity reversible color-changing fabric is prepared by the following steps:

s1, preparing a plain cotton fabric with a fabric aperture of 30 mu m as a fabric to be treated;

s2, preparing a functionalized emulsion containing a color-changing group compound according to the preset fabric aperture size of the fabric, wherein the particle size of latex particles of the functionalized emulsion is about 0.005 times of the preset fabric aperture, namely about 150 nm; the concrete composition is as follows:

the functionalized emulsion comprises the following components in parts by weight: 30-60 parts of methyl methacrylate, 40-80 parts of butyl acrylate, 3-10 parts of hydroxyethyl methacrylate, 0-30 parts of an inter-latex particle cross-linking agent, 1-10 parts of a spiropyran compound, 1-3 parts of an initiator, 0.5-5 parts of an emulsifier, 0.3-2 parts of a neutralizer and 150-300 parts of deionized water. The functionalized emulsion is prepared by the following method:

uniformly mixing an emulsifier, a neutralizer and deionized water, and completely dissolving the emulsifier and the neutralizer to prepare an aqueous solution; uniformly mixing methyl methacrylate, butyl acrylate, hydroxyethyl methacrylate, an inter-latex particle cross-linking agent and a spiropyran compound to obtain an oil phase, adding the oil phase into an aqueous phase solution, carrying out ultrasonic pre-emulsification in an ice bath, placing the mixed solution into a 70 ℃ water bath after 5min, adding an aqueous solution of an emulsifier to initiate polymerization reaction, and obtaining a functional emulsion after 6h for later use.

S3, cleaning the plain cotton fabric obtained in the step S1 by adopting sodium dodecyl sulfate, and drying the plain cotton fabric overnight for storage; cutting a plain cotton fabric with a proper size, fixing the fabric at the bottom of a culture dish, uniformly spraying and dip-dyeing a proper amount of the functionalized emulsion prepared in the step S2 on the cotton fabric, wherein the adsorption capacity of the functionalized emulsion is 50% of the mass of the fabric; and pre-baking and baking to obtain the photochromic fabric with high sensitivity.

And dipping, adsorbing or spraying the functional emulsion on the fabric to be treated, and then pre-drying and baking to obtain the high-sensitivity reversible color-changing fabric.

The test shows that the minimum pressure of force-induced color change of the high-sensitivity reversible color-changing fabric is 2N.

The prepared high-sensitivity reversible color-changing fabric was subjected to inkless writing of a T-shape (writing pressure of 5N) on the surface thereof using a pressure pen having a pen point diameter of 0.5mm, and the test results are shown in FIG. 3. It can be seen that the fabric surface presents a purple T shape, the white light is adopted to irradiate the color-changing part, the T shape can disappear, and the fabric surface restores the original appearance.

The surface of the high-sensitivity reversible color-changing fabric prepared by using an ultraviolet pen (the diameter is 5mm) with the wavelength of 365nm writes a WTU character without ink, and the test result is shown in figure 4. It can be seen that the fabric surface appeared "WTU" character, and was completely faded after 5min of white light irradiation.

Examples 2 and 3

The high-sensitivity reversible color-changing fabrics provided in examples 2 and 3 are different from those provided in example 1 in that, in step S1, the cotton fabrics are twill cotton fabrics and satin cotton fabrics, respectively. The rest is substantially the same as that of embodiment 1, and will not be described herein.

Examples 4 to 11

Compared with the fabric obtained in the embodiment 1, the high-sensitivity reversible color-changing fabric provided in the embodiments 4 to 11 is different in that the pore size of the cotton fabric and the particle size of the functionalized emulsion are shown in table 1. The rest is substantially the same as that of embodiment 1, and will not be described herein.

The same pressure and uv light measurements as in example 1 were used and the results are shown in table 1.

TABLE 1 preparation conditions and test results for examples 4-11

As can be seen from Table 1, when the latex particle size of the functionalized emulsion is the same, the surface of the cotton fabric is more sparse along with the increase of the pore size of the cotton fabric, fewer latex particles can be borne, the latex particles are easy to form a film by self, the stress concentration effect is not obvious, the lower limit value of the force-sensitive color-changing pressure is increased, and the force-sensitive color-changing sensitivity is reduced. When the aperture of the cotton fabric is increased, the particle size of the emulsion particles is correspondingly increased, and the matching degree of the aperture and the particle size is better, the lower limit value of the force-sensitive color-changing pressure is lower, and the force-sensitive and photosensitive color-changing sensitivity is improved. When the aperture of the cotton fabric is fixed and the particle size of the latex particles is too small or too large, the lower limit value of the force-sensitive color-changing pressure is large, and the force-sensitive color-changing sensitivity is reduced.

Examples 12 to 13

The high-sensitivity reversible color-changing fabrics provided in examples 12 to 13 were different from those in example 1 in that the adsorption amount in step S3 is shown in table 2. The rest is substantially the same as that of embodiment 1, and will not be described herein.

Table 2 preparation conditions and test results of examples 12 to 13

As can be seen from Table 2, with the increase of the adsorption capacity of the fabric to the functionalized emulsion, the higher the content of the force-sensitive color-changing group, the smaller the lower limit value of the force-sensitive color-changing pressure, the more obvious the force-sensitive color-changing effect and the photosensitive color-changing effect are.

Comparative example 1

Compared with the example 1, the high-sensitivity reversible color-changing fabric is different in that no latex inter-particle cross-linking agent is added into the functionalized emulsion in the step S2. The rest is substantially the same as that of embodiment 1, and will not be described herein.

TABLE 3 test results of examples 1 to 3 and comparative example 1

Test examples	Lower limit of force-sensitive color-changing pressure (N)	Force sensitive color change effect	Photochromic effect
				Example 1	2	Obvious color change	Obvious color change
Example 2	3	Obvious color change	Obvious color change
				Example 3	5	Obvious color change	Obvious color change
Comparative example 1	10	Is not obvious	Obvious color change

As can be seen from Table 3, if no cross-linking agent between latex particles is added into the functionalized emulsion, the lower limit value of the force-sensitive color-changing pressure is relatively large, the light-sensitive color-changing effect is obvious, but the force-sensitive color-changing effect is not obvious, because the latex film has relatively low mechanical property and is easy to crack and can not change color under the action of force without the cross-linking agent between latex particles.

In conclusion, the composition and the particle size of the functional emulsion are regulated and controlled based on the loose porous structure of the fabric, so that the particles of the functional emulsion are uniformly dispersed in the porous structure of the fabric, and the color-changing coating is modified, thereby obtaining the optimal matching relationship between the fabric structure and the color-changing coating structure. Under the optimal matching relationship, the prepared color-changing fabric has optimal comprehensive performance and higher universality, and an effective way is provided for the preparation of the color-changing fabric coating.

Although the present invention has been described in detail with reference to the preferred embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the spirit and scope of the present invention.