阅读说明：本技术 层状高空隙率材料 (Layered high porosity materials ) 是由 W·J·W·巴克 于 2020-04-15 设计创作，主要内容包括：本发明涉及一种包含复合表面层的层状高空隙率材料,该复合表面层包含结构材料,以及衍生自具有2-15个碳原子的脂肪族多元醇与具有3-15个碳原子的脂肪族多元羧酸的聚酯,其中所述表面层连接到结构材料的高空隙率层。与没有复合表面层的高空隙率材料相比,该材料具有改进的表面特性和改进的弯曲刚度,同时保持了隔音和隔热性能。该材料可用作例如绝缘材料、过滤材料或用于水培。(The present invention relates to a layered high porosity material comprising a composite surface layer comprising a structural material and a polyester derived from an aliphatic polyol having 2 to 15 carbon atoms and an aliphatic polycarboxylic acid having 3 to 15 carbon atoms, wherein said surface layer is attached to the high porosity layer of the structural material. The material has improved surface characteristics and improved bending stiffness while maintaining sound and thermal insulation properties compared to high void fraction materials without a composite surface layer. The material can be used, for example, as an insulating material, as a filter material or for hydroponics.)

1. A layered high porosity material comprising a composite surface layer; the composite surface layer comprises a structural material, and a polyester derived from an aliphatic polyol having 2 to 15 carbon atoms and an aliphatic polycarboxylic acid having 3 to 15 carbon atoms; wherein the surface layer is attached to a high-porosity layer of a structural material, the layered high-porosity material having a porosity of at least 0.5, as calculated from the density of the layered high-porosity material and the density of the substance from which the layered high-porosity material is constructed.

2. The layered high porosity material according to claim 1, having a porosity of at least 0.6, more particularly at least 0.7, and usually at most 0.98, particularly at most 0.95.

3. The layered high void content material as claimed in any one of the preceding claims, wherein the structural material is selected from ceramic wool, including glass wool and rock wool; a polymer-based material; animal source materials such as wool and down; a cellulose-based material; and combinations thereof, preferably cellulose-based materials.

4. Layered high void content material according to any of the preceding claims, wherein the starting material has a void content of at least 0.5, in particular at least 0.6, more in particular at least 0.7, still more in particular at least 0.8, and/or at most 0.995, in particular at most 0.98.

5. The layered high void content material as claimed in any one of the preceding claims, wherein the polymer content of the composite surface layer is in the range of 50 to 98 wt.%, more particularly in the range of 70 to 95 wt.%, based on the weight of the composite surface layer.

6. The layered high porosity material according to any of the preceding claims, wherein the porosity of the composite surface layer is in the range of 0.01 to 0.99, in particular in the range of 0.4 to 0.95.

7. The layered high porosity material according to any of the preceding claims, wherein observing the cross section of the layered material of the invention, the composite surface layer or layers constitute at most 50% of the cross section; wherein in case both surfaces of the layered material are provided with composite surface layers, all composite surface layers together preferably constitute 2-50%, in particular 5-40% of the cross-section; in the case where only one surface of the layered material is provided with a composite surface layer, said composite surface layer preferably constitutes 2-30%, in particular 5-20% of the cross-section.

8. The layered high void volume material according to any one of the preceding claims, wherein the aliphatic polyol is selected from the group consisting of triols and diols, the triols being selected from the group consisting of glycerol, sorbitol, xylitol and mannitol; the diol is selected from 1, 2-propanediol, 1, 3-propanediol and 1, 2-ethanediol; the aliphatic polyol is in particular chosen from glycerol, sorbitol, xylitol and mannitol, more in particular from glycerol.

9. The layered high void content material according to any one of the preceding claims, wherein the aliphatic polycarboxylic acid is selected from dicarboxylic acids and tricarboxylic acids, the dicarboxylic acids being selected from itaconic, malic, succinic, glutaric, adipic and sebacic acids; the tricarboxylic acid is selected from the group consisting of citric acid, isocitric acid, aconitic acid (cis and trans), and 3-carboxy-cis, cis-muconic acid; the aliphatic polycarboxylic acid is chosen in particular from itaconic acid, succinic acid and citric acid, more particularly from citric acid.

10. A process for the manufacture of a layered high porosity material according to any of the preceding claims comprising the step of contacting the surface of the structural material with a liquid medium comprising a polymer, and a curing step; the step of contacting is continued until the liquid medium partially, but not completely, impregnates the construction material.

11. The method according to claim 10, wherein the step of contacting the surface of the construction material with the liquid medium is performed by dipping, spraying, flowing, rolling, brushing or pouring, in particular by dipping.

12. The method according to any of the preceding claims 9 or 10, wherein the curing step is carried out at a product temperature of 80-250 ℃, in particular 100-200 ℃, and preferably in an inert atmosphere.

13. A method according to any of claims 10-12, wherein the application of the further surface layer is combined in the manufacture of the layered material according to the invention by applying the further material to the layered material after the provision of the polymer but before the curing step, and providing the combined structure to the curing step.

14. Use of a material according to any one of claims 1-9 as an insulating or filtering material or in hydroponics.

15. A method of processing a material according to any one of claims 1 to 9, wherein one or more of the following steps are carried out:

-providing a material according to any of claims 1-9 in a self-supporting structure, optionally after providing a frame and/or incorporating therein a reinforcing structure such as a beam, wherein the front, preferably the front and the back, in particular the front, the back and the sides of the material are provided with a composite layer;

-providing openings on a material according to any of claims 1-9, in particular a cellulose-based material, before or after application of a polymer;

-providing a structure allowing panels to be connected to each other and a structure allowing panels to be connected to other structures on a material according to any of claims 1-9, in particular the material is a cellulose-based material;

-providing a fastening means on a material according to any of claims 1-9, in particular a cellulose-based material.

Technical Field

The present invention relates to a layered high porosity material. The invention particularly relates to layered high porosity materials having a composite surface layer. It has been found that the layered high porosity material according to the invention shows improved properties compared to high porosity materials without a composite surface layer.

Background

Many insulating materials, whether thermal or acoustical insulation, are high void-fraction (high void-fraction) materials. They rely essentially on stagnant air trapped between solid structures such as fibers, particles or layers. Examples of insulating materials are mineral or glass wool or mats and boards based on polymers, such as polyurethane, whether curved or flat. Recent developments have been the use of high void content boards based on renewable cellulose-based materials (such as hemp, flax, cotton, metises and paper/cardboard, etc.), as well as materials of animal origin (such as wool or down, etc.). Most of these high porosity materials do not have structural strength or bending stiffness. They therefore need to be used in conjunction with building frames, and often with surface coverings (such as plasterboard or other sheet-like materials) to provide mechanical strength, fire resistance and surface structure, including painting, wallpapering or otherwise providing an attractive visual appearance.

However, the combination of a flexible high void volume insulation and a separate board cover has a number of disadvantages. The fact that at least two types of material must be installed separately necessitates an installation process having at least two steps, which makes it labor intensive. Furthermore, it requires additional material. Furthermore, the use of solid (non-porous) sheet material may offset any sound absorption characteristics of the insulation material. Furthermore, it may adversely affect the temperature/humidity and other climate regulating properties of the cellulose-based material and will lead to increased carbon dioxide emissions. In addition, most gypsum board and wood panels are under scrutiny for possible emissions of radioactive radon gas, as well as carcinogenic and toxic formaldehyde gases.

Accordingly, there is a need in the art for a high void fraction material that has increased mechanical strength and that can eliminate the use of a cover sheet, thereby addressing the above-mentioned problems. The new materials can also be used in other applications where high porosity materials are used, such as filtration and hydroponic applications.

Disclosure of Invention

The present invention relates to a layered high porosity material comprising a composite surface layer comprising a structural material and a polyester derived from an aliphatic polyol having 2 to 15 carbon atoms and an aliphatic polycarboxylic acid having 3 to 15 carbon atoms, wherein said surface layer is attached to the high porosity layer of the structural material.

It has been found that materials having a composite surface layer have improved mechanical strength compared to the high porosity structural material itself. Furthermore, it can be used without a surface covering. It may also require less mechanical frame support. Further advantages of the material according to the invention will become apparent from the further description.

It is noted that WO2012/140238 describes the use of polyester polymers derived from aliphatic polyols having 2-15 carbon atoms and aliphatic polycarboxylic acids as coatings or in the manufacture of laminates. This reference does not disclose providing a high void fraction material having a polyester composite surface layer.

The invention and its preferred embodiments and their associated advantages are discussed in more detail below.

Brief description of the drawings

The invention is illustrated by, but not limited to, the following figures:

fig. 1 shows a picture of a panel according to the invention and its starting material, wherein the difference in free-standing properties can be seen.

Fig. 2 shows the surface strength of a panel according to the invention.

Figure 3 shows an embodiment in which a beam is introduced between two panels.

Fig. 4 shows a self-supporting structure of a set of panels in a frame.

Figure 5 shows a panel with a cloth cover.

Detailed Description

The layered high porosity material comprises a composite surface layer comprising a structural material and a polyester, the surface layer being attached to a high porosity layer of the structural material.

The presence of a composite surface layer in combination with a layer of structural material is a key feature of the invention. This means that when observing a cross-section of the layered material according to the invention, part of the material comprises polyester and part of the material does not. In other words, the polyester-containing composite surface layer can be distinguished from the layer of structural material that does not contain polyester. The boundary between the two layers can be easily determined by visual inspection or by analyzing the polymer content of the layers at different locations in the material. The boundary may be identified by a step-wise change in polymer content over a short distance, for example, at least a 5-fold increase in polymer content over a distance of 2cm, optionally over a distance of 1cm, optionally over a distance of 0.5cm, optionally over a distance of 0.2 cm.

The composite surface layer may be present on one side of the material, or on more than one side of the material. For example, when the material has a panel-like shape, i.e. a shape in which the length and width of the material are significantly greater than the thickness, there may also be a composite surface layer on both major faces of the material. In this case, the layer of structural material will be sandwiched between the two composite surface layers and may therefore also be considered a core layer. It is also possible and may be preferred to provide a composite layer on one or more sides of the panel.

The layered high porosity material may be made from conventional high porosity structural materials used in the art as thermal and/or acoustical insulation. Examples are panels and mats, whether planar or shaped, based on ceramic wool, such as glass wool and rock wool; polymer-based panels, cellulose-based panels, and animal product-based materials such as wool, feathers, and down. Of course, the high void fraction material used in the present invention may also comprise a mixture of various components, such as a cellulose-based material in combination with asbestos or glass wool or the like. The starting material may be planar or curved, for example in the form of (semi-cylinders) for insulating curved surfaces.

The starting material has a high porosity, for example a porosity of at least 0.5, in particular at least 0.6, more in particular at least 0.7, more in particular at least 0.8. As a general upper limit, values of at most 0.995, in particular at most 0.98, may be mentioned. The void fraction may be calculated from the density of the high void fraction material itself (i.e., the blanket or panel) and the density of the constituents that make up the material (e.g., glass, stone, polymer, or cellulose-based material). Thus, the void fraction reflects the volume of void volume in the material (which may be filled with a gas, such as air) relative to the total volume of the material. The values given above also apply to the high-porosity layer of the structural material of the layered high-porosity material according to the invention. Thus, the porosity of the layered high porosity material can be calculated from the density of the layered high porosity material and the density of the substance constituting the layered high porosity material.

The cellulose-based material may be based on any cellulose-containing material. Examples include wood pulp and paper, including cardboard. In one embodiment, the cellulose-based material is derived from so-called virgin pulp, which is obtained directly from the wood pulping process. This pulp may be from any plant material, but mainly from wood. Wood pulp is derived from softwood trees such as spruce, pine, fir, larch and hemlock, and hardwood trees such as eucalyptus, boxwood (populus), poplar and birch. In one embodiment, the cellulose-based material comprises cellulosic material derived from recycled paper, such as cellulosic pulp obtained from recycled books, paper, newspapers and periodicals, egg boxes, and other recycled paper or paperboard products. Combinations of cellulose sources may also be used. The cellulose-based material may also be derived from flax, hemp or cotton sources, among other renewable plant-based materials. The term cellulose-based material is intended to mean that the object comprises at least 50 wt.% of a cellulose material, e.g. derived from, e.g., fresh or used paper, fresh or used cardboard, wood or any other form of plant material, or a combination thereof. In particular, the material or container comprises at least 70 wt.%, more in particular at least 80 wt.% of cellulosic material.

The starting material is usually in the form of a layer, sheet, mat or panel, which in the context of this specification are synonyms referring to a shape in which the length and width of the material are significantly greater than the thickness.

Typically, the starting material has a thickness of at least 0.5cm, in particular at least 1 cm. As a general upper limit, values of up to 40cm may be mentioned. The thickness of the starting material may preferably be 1 to 30cm, in particular 2-15 cm. The width and length of the starting material are not critical to the present invention. Both are typically at least 3 times the thickness of the starting material, for example at least 30cm, in particular at least 50 cm. The width is generally not more than 4 meters, in particular for practical purposes, at most 2 meters. The length of the material may be indefinite, wherein the material is manufactured in a continuous process. For practical purposes, the length may be at most 20m, in particular at most 15 meters, e.g. at most 8 meters, usually at most 4 meters, depending on the application.

The same dimensions apply to the layered high porosity material according to the invention.

The layered high void content material includes a layer of structural material and a composite surface layer comprising the structural material and polyester. The composite surface layer is connected with the structural material layer through the structural material. For example, when the high porosity material is an asbestos mat, the composite surface layer is composed of asbestos and a specified polyester, and the composite surface layer is connected to the structural material layer by asbestos fibers. In other words, the structural material is continuous at the boundary between the layer of structural material and the composite surface layer comprising the structural material and the polyester.

The polymer content of the composite surface layer is typically in the range of 50 to 99 wt.%, more particularly in the range of 70 to 95 wt.%, calculated on the weight of the composite surface layer.

The composite surface layer typically has a void fraction in the range of 0.01 to 0.99, in particular in the range of 0.4 to 0.95. The porosity of the composite layer may be calculated from the density of the composite layer and the density of the polymer and structural materials in the composite layer. Although the porosity is reduced compared to the starting material and the structural material layer of the layered material, it can still be quite high. This means that the sound absorption properties of the construction material are at least partly maintained. This is in contrast to the prior art where the provision of a sheet in front of the insulation material significantly affects the sound absorption properties of the material.

The porosity of the layered high porosity material of the present invention is still relatively high, such as at least 0.5, particularly at least 0.6, more particularly at least 0.7. As a general upper limit, values of at most 0.98, more particularly at most 0.95, may be mentioned. It retains its thermal and acoustic insulation properties to a large extent due to the high void fraction in the product. Furthermore, high void content in the product is accompanied by lower panel weight, which is attractive for a number of reasons, including panel handling, transportation, etc.

It has been found that providing a composite surface layer can improve the properties of the high porosity material, such as bending stiffness, while still maintaining an overall high porosity in the final product, which ensures the maintenance of the insulating properties. More specifically, it has been found that it is possible to obtain a material wherein the porosity of the final product is in the range of 75-99.5%, in particular in the range of 80-99.5%, more in particular in the range of 85-99.5%, compared to the porosity of the starting product.

The thickness of the composite surface layer is typically in the range of 1mm to 40mm, depending on the total thickness of the layered high porosity material. Composite layers with a thickness below 1mm are generally too thin to provide the desired surface structure. A thickness of more than 40mm generally does not lead to a further improvement in performance but only to an increase in the weight of the material. The thickness of the composite surface layer may preferably be 2-30mm, in particular 4-15 mm.

The layered material according to the invention thus comprises one or more composite surface layers and one back or core layer.

Typically, looking at a cross-section of the layered material of the invention, the composite surface layer (or layers) will constitute at most 50% of the cross-section. In the case of a layered material provided with composite surface layers on both surfaces, the composite surface layers together preferably constitute 2-50%, in particular 5-40%, of the cross section. In the case of a layered material provided with a composite surface layer on only one surface, the composite surface layer preferably represents 2 to 30%, in particular 5 to 20%, of the cross section.

The amount of polymer on the final product can vary within wide limits. In interpreting these values, it should be taken into account that the starting material is relatively light due to its high porosity. Thus, a relatively large weight percentage of polymer on the final product may still correspond to a relatively thin surface layer. Typically, the amount of polymer on the final layered material is in the range of 10 to 95 wt.%, based on the total weight of the layered material, more particularly 25 to 80 wt.%.

The material according to the invention has improved mechanical properties, in particular increased bending stiffness and surface hardness, compared to the material from which it is derived. Furthermore, it may have more attractive surface characteristics, in particular increased smoothness. Furthermore, the noise reduction properties of the starting material are maintained, while the mechanical properties are improved.

The present invention utilizes polyesters derived from aliphatic polyols having 2 to 15 carbon atoms and aliphatic polycarboxylic acids having 3 to 15 carbon atoms.

The starting materials for the present invention are aliphatic polyols having 2 to 15 carbon atoms and aliphatic polycarboxylic acids.

The aliphatic polyol used in the present invention contains at least two hydroxyl groups, particularly at least three hydroxyl groups. Typically, the number of hydroxyl groups will be 10 or less, more particularly 8 or less, or even 6 or less, particularly two or three. The polyol has 2 to 15 carbon atoms. More particularly, the polyols have 3 to 10 carbon atoms. Preferably the polyol does not contain a N or S heteroatom. More specifically, it is preferred that the polyol does not contain non-carbon groups other than hydroxyl groups. More particularly, the polyol is an aliphatic polyalkanol comprising only C, H and O atoms. In a preferred embodiment of the present invention, the polyol contains a relatively large number of hydroxyl groups compared to its number of carbon atoms. For example, the ratio of the number of hydroxyl groups to the number of carbon atoms is from 1:4 (i.e., one hydroxyl group per four carbon atoms, or 8 carbon atoms per diol) to 1:0.5 (i.e., 2 hydroxyl groups per carbon atom). In particular, the ratio between the number of hydroxyl groups and the number of carbon atoms ranges from 1:3 to 1:1, more particularly from 1:2 to 1:1. One particularly preferred group of polyols is where the ratio is 1:1.5 to 1:1. Compounds in which the ratio of hydroxyl groups to carbon atoms is 1:1 are considered to be particularly preferred.

Examples of suitable polyols include triols selected from glycerol, sorbitol, xylitol and mannitol, and diols selected from 1, 2-propanediol, 1, 3-propanediol and 1, 2-ethanediol. Preference is given to using compounds selected from glycerol, sorbitol, xylitol and mannitol, particular preference to using glycerol.

The preference for glycerol is based on the following points: firstly, glycerol has a melting point of 20 ℃ and is therefore easy to process, in particular in comparison with xylitol, sorbitol and mannitol, which all have melting points well above 90 ℃. Furthermore, it has been found that glycerol provides a high quality polymer, thus combining the use of readily available source materials with good processing conditions and a high quality product. Mixtures of different types of alcohols may also be used.

However, it is preferred that the polyol consists of at least 50 mol% glycerol, xylitol, sorbitol or mannitol, particularly preferably at least 70 mol%, more particularly at least 90 mol%, or even at least 95 mol% glycerol. In one embodiment, the polyol consists essentially of glycerol.

The production of biodiesel by-product glycerol from the transesterification of glycerides with monohydric alcohols is a specific embodiment of the present invention. Suitable monoalcohols include C1-C10 monoalcohols, particularly C1-C5 monoalcohols, more particularly C1-C3 monoalcohols, particularly methanol. Glycerides are mono-diesters and esters of glycerol and fatty acids, which typically have from 10 to 18 carbon atoms. Suitable methods for producing biodiesel with associated glycerol are known in the art.

The aliphatic polycarboxylic acids used in the present invention comprise at least two carboxylic acid groups, in particular at least three carboxylic acid groups. In general, the number of carboxylic acid groups will be 10 or less, more particularly 8 or less, or even 6 or less. The polycarboxylic acids have 3 to 15 carbon atoms. More particularly, the polycarboxylic acids have from 3 to 10 carbon atoms. Preferably the polycarboxylic acid does not contain a N or S heteroatom. More specifically, it is preferred that the polycarboxylic acid does not contain non-carbon groups other than carboxylic acid groups. More particularly, the polycarboxylic acid is an aliphatic polycarboxylic acid containing only C, H and O atoms.

In one embodiment, a dicarboxylic acid is used. If used, the dicarboxylic acid can be any dicarboxylic acid having two carboxylic acid groups and typically up to 15 carbon atoms. Examples of suitable dicarboxylic acids include itaconic acid, malic acid, succinic acid, glutaric acid, adipic acid, and sebacic acid. Itaconic acid and succinic acid may be preferred.

In one embodiment, a tricarboxylic acid is used. If used, the tricarboxylic acid may be any tricarboxylic acid having three carboxylic acid groups and generally up to 15 carbon atoms. Examples include citric acid, isocitric acid, aconitic acid (cis and trans) and 3-carboxy-cis, cis-muconic acid. For cost and availability reasons, it is considered preferable to use citric acid.

Where applicable, the polycarboxylic acid may be provided in whole or in part in the form of an anhydride, for example citric anhydride.

It has been found that the use of tricarboxylic acids results in polyesters with attractive properties. Thus, in one embodiment, the polyacid comprises at least 10 weight percent of the tricarboxylic acid, whether or not in combination with the dicarboxylic acid, other tricarboxylic acids, and mixtures thereof. In one embodiment, the polyacid comprises at least 30 wt.% of tricarboxylic acid, preferably at least 50 wt.%, calculated on the total amount of polyacid. In one embodiment, the amount of tricarboxylic acid is at least 70 wt.%, more specifically at least 90 wt.%, or even at least 95 wt.%. In one embodiment, the polyacid consists essentially of a tricarboxylic acid, where the term essentially means that other acids may be present in amounts that do not affect the properties of the material.

In another embodiment of the invention, the acid comprises at least 10 wt.% dicarboxylic acid, preferably at least 30 wt.%, more preferably at least 50 wt.%, calculated on the total amount of acid. In one embodiment, the amount of dicarboxylic acid is at least 70% by weight.

In one embodiment, the acid comprises at least 10 wt.% of a tricarboxylic acid and at least 2 wt.% of a dicarboxylic acid, more particularly a combination of at least 10 wt.% of a tricarboxylic acid and at least 5 wt.% of a dicarboxylic acid, or at least 10 wt.% of a tricarboxylic acid and at least 10 wt.% of a dicarboxylic acid. In this embodiment, the weight ratio between the two acids may vary within wide ranges depending on the properties of the desired material. In one embodiment, the dicarboxylic acid comprises 2 to 90 wt.%, specifically 5 to 90 wt.%, more specifically 10 to 90 wt.% of the total amount of dicarboxylic acid and tricarboxylic acid, depending on the desired material properties. It should be noted that the preferred ranges for the tricarboxylic acids described above also apply to this embodiment. It has been found that the use of a tricarboxylic acid, in particular citric acid, in combination with the use of a triol, for example glycerol, in particular, leads to the formation of a high-quality composite.

Without wishing to be bound by theory, we believe that there are many reasons why the use of triacids, particularly in combination with triols, results in the formation of high quality composites. First, the use of triacids, particularly in combination with triols, can result in highly crosslinked polymers, thereby increasing strength.

Furthermore, where a triacid is used, and preferably a triol is also used, it is likely that the acid or hydroxyl groups will physically or chemically interact with reactive groups on the cellulose-based material. This results in improved adhesion between the cellulose-based material and the polymer, which is a key requirement for the manufacture of composite materials. The degree of interaction can be controlled by the choice of the amounts of triacid and triol and by the choice of degree of polymerization.

The molar ratio between the polyol and the polyacid will be determined by the ratio between the number of reactive groups in the alcohol and acid used. In general, the ratio of the number of OH groups to the number of acid groups is in the range of 5:1 to 1: 5, or more. More specifically, the ratio may be between 2:1 and 1:2, more specifically between 1.5:1 and 1:1.5, more preferably between 1.1:1 and 1: 1.1. The theoretical molar ratio is 1:1.

The polymer is formed by combining an alcohol and an acid to form a liquid phase. Depending on the nature of the compound, this can be done, for example, by heating the mixture of components to a temperature at which the acid will dissolve in the alcohol, in particular glycerol. Depending on the nature of the compound, this may be, for example, at 20-200 ℃, e.g., 40-200 ℃, e.g., 60-200 ℃, or 90-200 ℃. In one embodiment, the mixture can be heated and mixed at a temperature of 100-.

Optionally, a suitable catalyst may be used to prepare the polyester. Suitable catalysts for making polyesters are known in the art. Preferred catalysts are those which are free of heavy metals. Useful catalysts are strong acids such as, but not limited to, hydrochloric, hydroiodic and hydrobromic acids, sulfuric acid (H)₂SO₄) Nitric acid (HNO)₃) Chloric acid (HClO)₃) Boric acid, perchloric acid (HClO)₄) Trifluoroacetic acid and trifluoromethanesulfonic acid. Catalysts such as zinc acetate and manganese acetate may also be used, although they may be less preferred.

Optionally, after polymerization and cooling of the reaction mixture, the mixture may be (partially) neutralized with a volatile base such as ammonia or an organic amine to stabilize the polyester solution. Preferred amines are those having a low odor such as, but not limited to, 2-amino-2-ethyl-1, 3-propanediol, 2-amino-2-methyl-1-propanol, 2-dimethylamino-2-methyl-1-propanol.

In one embodiment, compounds are added to increase the interaction of the polymer with the hydrophobic material, or to increase the water resistance of the final product. Suitable compounds include, for example, C5 to C22 saturated or unsaturated fatty acids or salts thereof, C5 to C22 saturated or unsaturated fatty alcohols, and dimeric and trimeric fatty acids or alcohols. For example, glyceryl monostearate, triethyl citrate and valeric acid have been successfully used in the present invention.

The hydrophobicity-increasing compound is generally applied in an amount of 0.1-5 wt.%, more particularly 0.3-3 wt.%, calculated on the amount of polymer.

A layered material comprising a layer of a structural material having a composite surface layer comprising the structural material and a polyester derived from an aliphatic polyol having from 2 to 15 carbon atoms and an aliphatic polycarboxylic acid having from 3 to 15 carbon atoms is typically prepared by: the surface of the structural material is contacted with a liquid medium comprising a polymer until the structural material is partially, but not completely, impregnated with the liquid medium, and then subjected to a curing step.

In this application, the degree of polymerization of a monomer will be expressed as the conversion, which is the ratio of the fraction of functional groups that react at a certain point in time to the maximum of those functional groups that can react. The conversion can be determined from the acid number of the reaction mixture compared with the theoretical acid number of all monomers present. The conversion can also be determined gravimetrically by the loss of water which occurs during the polymerization.

Typically, when the polymer is applied to a high void content starting material, its conversion (as determined by acid number) ranges from 0.05 to 0.6, specifically from 0.1 to 0.5, more specifically from 0.2 to 0.5.

After curing, the conversion, measured gravimetrically, is generally at least 0.6, specifically at least 0.7, more specifically at least 0.8, and in some embodiments at least 0.9. The maximum conversion was 1.0.

Since it is intended to obtain an object comprising a layer of structural material and a composite surface layer comprising the structural material and polyester, it is important to choose the manufacturing conditions such that the liquid medium does not penetrate the entire structural material. The effect is mainly controlled by the following parameters: the manner of application of the liquid medium, the amount of liquid medium, the viscosity of the liquid medium, the absorbent capacity of the structural material impregnated with the liquid medium, and the rate of polymerization of the polymer in the absorbent medium.

The viscosity of the liquid medium is determined by, for example, the degree of conversion of the polyester in the medium, the temperature, and optionally the presence of a solvent such as water. The polymerization rate of the polymer is determined by, for example, the presence of catalyst, temperature, and water removal efficiency (water is a by-product of the reaction). In view of these parameters, it is within the purview of the skilled artisan to select suitable contacting conditions.

For example: the structural material may be contacted with an aqueous solution of polyester at room temperature. It is also possible to contact the structural material with the polyester in liquid form at elevated temperature.

The liquid medium comprising the polymer can be applied to the high porosity starting material by methods known in the art, such as dipping, spraying, flowing, rolling, brushing, or pouring.

It has been found to be advantageous to dip-coat the construction material into a liquid medium comprising a polymer, since this results in a surface layer with a reproducible thickness. This process is easily applied by placing the layered material in a polymer bath for a controlled period of time.

When it is desired to provide surface layers on both sides of the panel, a polymer layer may be applied on either side of the panel, followed by a single curing step. However, it may be preferred to apply a first layer to one side of the panel, perform the curing step, then apply a second layer on the other side of the panel, followed by a second curing step.

After the polyester is applied to the structural material, the resulting impregnated material is subjected to a curing step to increase the degree of polymerization of the polyester. The key to the curing step is that the polyester is at a reaction temperature, for example, a product temperature of between 80-250 deg.C, particularly between 100 deg.C and 200 deg.C. Curing can be carried out in heating equipment known in the art, for example in an oven having an oven temperature of 80 ℃ up to 450 ℃. Different types of ovens may be used, including but not limited to belt ovens, tunnel ovens, convection ovens, microwave ovens, infrared ovens, induction ovens, hot air ovens, conventional bake ovens, and combinations thereof. Curing may be accomplished in one step or in multiple steps, depending on the desired application. The curing time varies from 5 seconds to 2 hours, depending on the application and the type of oven and temperature used. It is within the purview of one skilled in the art to select suitable curing conditions depending on the desired application and the desired properties. It may be preferred to carry out the curing step in an inert gas atmosphere, for example under nitrogen, in particular in the absence of oxygen. The use of an inert atmosphere allows the use of higher curing temperatures while limiting the occurrence of undesirable oxidation reactions.

If desired, the impregnated material may be subjected to a drying step prior to being subjected to the curing step. The drying step is typically carried out at room temperature, for example 15 ℃ or a temperature of 20 ℃ to 100 ℃, to remove water from the composite. It may be carried out, for example, for 0.25 hours to 3 days, depending on the amount of water in the composite, the thickness of the layer and the temperature.

In one embodiment, the use of a further surface layer is incorporated in the manufacture of the layered material according to the invention. In this case, the facing material is applied to the panel after the polymer is provided but before the curing step, and the combined structure is provided to the curing step. This method allows the manufacture of panels with attractive properties, such as an attractive surface structure and improved surface strength. The surface material may be, for example, a layer of woven or non-woven fabric. In this case, the surface layer is preferably porous so that it can absorb the polymer. Surface materials also include other materials that modify the surface of the product, such as powders, flakes, or other materials.

The layered material according to the invention can be used as a thermal and acoustic insulation material in a manner known in the art. In view of the improved surface properties of the material according to the invention, it is often possible to dispense with a covering layer such as plaster or other board material. The new materials can also be applied to other situations where high porosity materials are used, such as filtration and hydroponic applications.

Some preferred ways of processing the material according to the invention will be discussed below.

It has been found that the material of the invention has better mechanical properties and better self-supporting properties than the starting material from which it originates. This makes it possible to handle them in a novel way. In one embodiment, the front side, preferably the front side and the back side, in particular the front side, the back side and the side faces, of the material according to the invention have been provided with a composite layer; optionally after providing a frame and/or a reinforcing structure such as a beam incorporated therein, the material according to the invention is provided as a self-supporting structure.

It has been found that panels, particularly cellulose-based panels, prepared according to the present invention can readily provide openings to accommodate sockets such as power supplies, cables, and the like. The openings may be provided after the polymer is applied, in which case the increased mechanical strength makes the panel easy to process; or the opening may be provided before the polymer is applied, in which case the later provision of the polymer will ensure a smooth and strong surface of the opening. The panels may also be provided with structure before or after application of the polymer that allows the panels to be connected to each other, to other structures such as walls, frames, etc.

The improved mechanical strength of the panel, in particular of the panel surface, makes it possible to provide fastening means, such as screws, directly on the panel.

If desired, the surface of the final layered material may be provided with a cover layer, for example in the form of plaster, paint or wallpaper.

The present disclosure also includes the following items:

1. a layered high porosity material comprising a composite surface layer comprising a structural material and a polyester derived from an aliphatic polyol having from 2 to 15 carbon atoms and an aliphatic polycarboxylic acid having from 3 to 15 carbon atoms, wherein said surface layer is attached to the high porosity layer of the structural material.

2. The layered high porosity material according to item 1 having a porosity of at least 0.5, in particular at least 0.6, more in particular at least 0.7, and usually at most 0.98, in particular at most 0.95.

3. The layered high porosity material according to any of the preceding items, wherein the structural material is selected from the group consisting of ceramic wool, including glass wool and rock wool, polymer-based materials, animal-derived materials, such as wool and down, and cellulose-based materials, and combinations thereof, preferably cellulose-based materials.

4. The layered high porosity material according to any of the preceding items, wherein the starting material has a porosity of at least 0.5, in particular at least 0.6, more in particular at least 0.7, more in particular at least 0.8, and/or at most 0.995, in particular at most 0.98.

5. The layered high void content material according to any of the preceding items, wherein the polymer content of the composite surface layer is in the range of 50 to 98 wt.%, more particularly in the range of 70 to 95 wt.%, calculated on the weight of the composite surface layer.

6. The layered high porosity material according to any of the preceding items, wherein the porosity of the composite surface layer is in the range of 0.01 to 0.99, in particular in the range of 0.4 to 0.95.

7. The layered high porosity material according to any of the preceding items, wherein a cross section of the layered material of the invention is observed, the composite surface layer constituting at most 50% of the cross section, wherein in case both surfaces of the layered material are provided with composite surface layers, all composite surface layers together preferably constitute 2-50%, in particular 5-40% of the cross section; and in the case where only one surface of the material is provided with a composite surface layer, the composite surface layer preferably constitutes 2-30%, in particular 5-20%, of the cross-section.

8. The layered high void content material according to any of the preceding items, wherein the aliphatic polyol is selected from the trihydric alcohols of glycerol, sorbitol, xylitol and mannitol, and the diols selected from 1, 2-propanediol, 1, 3-propanediol and 1, 2-ethanediol, in particular from glycerol, sorbitol, xylitol and mannitol, more in particular from glycerol.

9. The layered high void volume material according to any one of the preceding items, wherein the aliphatic polycarboxylic acid is selected from the group consisting of dicarboxylic acids and tricarboxylic acids; the dicarboxylic acid is selected from itaconic acid, malic acid, succinic acid, glutaric acid, adipic acid, and sebacic acid; the triacid acid is selected from citric acid, isocitric acid, aconitic acid (cis and trans), and 3-carboxy-cis, cis-muconic acid, in particular from itaconic acid, succinic acid and citric acid, more in particular from citric acid.

10. A method for manufacturing a layered high porosity material according to any of the preceding items comprising contacting a surface of a construction material with a liquid medium comprising a polymer until the construction material is partially but not completely impregnated with the liquid medium and comprising a curing step.

11. The method according to clause 10, wherein the step of contacting the surface of the construction material with the liquid medium is carried out by dipping, spraying, flowing, rolling, brushing or pouring, in particular by dipping.

12. The process according to item 9 or 10, wherein the curing step is carried out at a product temperature of 80-250 ℃, in particular 100-200 ℃, preferably in an inert atmosphere.

13. The method according to any of the clauses 10-12, wherein the manufacturing of the layered material according to the invention is combined with the application of the further surface layer by applying the further material onto the material after providing the polymer but before the curing step and providing the combined structure to the curing step.

14. Use of the material according to any of items 1-9 as an insulating material, a filter material or in hydroponics.

15. The method for processing material according to any one of items 1-9, wherein one or more of the following steps are performed:

-a material according to any of the items 1-9, wherein the front side, preferably the front side and the back side, in particular the front side, the back side and the side surfaces of the material are provided with a composite layer; optionally after providing a frame and/or incorporating therein a reinforcing structure such as a beam, the material is provided in a self-supporting structure;

-the material according to any of the items 1-9, in particular the material is a cellulose-based material; having an opening before or after application of the polymer;

-the material according to any of the items 1-9, in particular the material is a cellulose-based material; the material having a structure that allows panels to be connected to each other and having a structure that allows panels to be connected to other structures;

-the material according to any of the items 1-9, in particular the material is a cellulose-based material; the material is provided with fastening means.

The invention will be illustrated by, but is not limited to, the following examples.

Examples

Example 1: cellulose-based panels-front and back

The prepolymer mixture was prepared as follows: 1.0kg of glycerol with a purity of > 99% and 2.0kg of citric acid (purity > 99%) were placed in a stirred and heated reactor. 9g of boric acid (0.5m/m, > 99% purity) were added as catalyst. The mixture was heated to 135 ℃ over about 15 minutes and held at this temperature for 15 minutes. Then, tap water was added to a polymer concentration of 20 wt%, and the mixture was cooled to room temperature. The conversion of the polymer was 0.4.

The formulation is repeated as often as necessary to obtain the desired amount of polymer solution.

A cellulose-based (recycled cardboard/paper) insulation board (8x50x120 cm) with a void volume of 0.92 and a density of 90 grams/litre, commercially available from EverUse, was immersed for 20 minutes at room temperature, with one of the side surfaces immersed in a layer of polymer solution (about 1cm deep) as described above. This is done in order for the panel to absorb part of the polymer. After 20 minutes, the panel was removed from the polymer layer and turned upside down with the wet side facing up. When the panel stopped dripping (about 5 minutes), the panel was subjected to a curing step in a vented oven at 170 ℃ (oven temperature) for 90 minutes. The panel was allowed to cool and absorb moisture for one day. A second coating was applied by dipping the panel with the uncoated side into a layer of polymer solution as described above for 30 minutes. The panel was then removed from the polymer layer and turned with the wet layer facing upward. When the panel stopped dripping (approximately 5 minutes), the panel was subjected to a curing step in an oven at 170 ℃ for 90 minutes. Both sides of the panel are now coated with a coating that allows it to cool and absorb moisture. After both sides were coated and cured, the panels were subjected to a second curing step (170 ℃, 60 minutes) after standing at room temperature for 24 hours, and the process was repeated after an additional 24 hours. .

Similar panels were prepared with higher curing temperatures and shorter curing times (190 ℃, 45 minutes) and shorter dip coating times (6-10 minutes).

The resulting product was a cellulose-based panel with a composite surface layer on both sides, an average thickness of 0.8cm, a density of 0.55 kg/liter and a void fraction of 0.62. The total density of the panels (composite and non-composite components) was about 180 grams/liter. The total void fraction of the panel was 0.86, which is 93% of the void fraction of the starting material.

No foam formation was observed during panel manufacture. Heating the polymer under the conditions applied here will generally result in foam formation. Obviously, in panel manufacture, all water is effectively removed without foaming.

Furthermore, the panels are odourless, with a hard surface. The panels can be easily machined, for example, by sawing and grinding. The composite layer is also vapor permeable, which means that the good climate regulating properties of the cellulosic material are maintained.

An important property of the impregnated sheet is self-supporting, whereas the starting material is not. Figure 1 shows a picture of a panel according to the invention (top) and its starting material (bottom). It can be seen from the figure that the product according to the invention has a high bending stiffness, whereas the starting material does not.

The panel was found to be a good surface for coating and the surface layer was sufficiently hard to allow the application of fastening means, such as screws. Figure 2 shows the strength of the panel surface according to the invention. The panel is provided with a screw, and the panel can be lifted up through the screw. When the screw is placed in the starting material in the same way, the screw is immediately torn from the material when the force is applied.

The panel has good moisture and water resistance. After 1 hour in boiling water, the composite surface layer was still intact.

Noise absorption characteristics

The starting sun visor is characterized by good noise absorption properties. It is desirable to maintain these characteristics when applying the composite layer. Thus, a model experiment was set up to test the noise absorption effect of the impregnated Everuse panels prepared as above.

One box consisted of 6 small panels (25 x 25 cm). The front panel of the box is the material to be tested. A sounder is disposed in the housing, facing the front panel. The sound source has a constant pitch of 432 Hz. A decibel meter was placed outside the box 30cm from the sound generator. The dB meter was measured continuously for one minute and the average was generated as shown in the following table.

The "Blanc" measurement without the front panel yielded a value of 91 dB. The result for the uncoated panel was 82 dB. The other panels all produced values within the same range, indicating that providing a composite layer did not adversely affect the sound absorption characteristics of the panels.

Panel type	dB
		Without front panel	91
Non-coated panel	82
		1 Top coat (coating facing sound source)	83
1 Top coat (uncoated side facing the sound source)	82
		Double-coating panel	83
Four-sided coating	81

Mechanical strength

To determine the mechanical strength of the composite layer, a portion of the composite layer is separated from the panel. Composite plies 90mm long, 19mm wide and 8mm thick were sawn out. For comparison purposes, sheets having the same dimensions were prepared from unimpregnated plaques. The tests were carried out in a tensile (M350-20CT) equipped with a 3-point bending test, spanning 80 mm. The compression speed was 1 mm/min. The composite layer samples averaged 70 newtons in breaking strength. The untreated panel cannot withstand a span of 80mm and collapses under its own weight.

Fire resistance

To test the fire resistance of the composite layer, a torch of flame was held on the surface of the panel composite layer for 5 minutes. The result was that the surface was blackened, but the surface layer did not catch fire.

Example 2: benefits of cellulose-based Panel-side impregnation

The panel may be impregnated on 6 sides to increase the overall strength of the panel and minimize the need for additional mechanical support frames for the panel. Thus, not only the top and bottom of the panel were impregnated, but also the edges of the panel were impregnated in order to test the effect on the strength of the panel.

Panels were made as follows using the starting materials and polymer solutions described in example 1. The front of the panel was placed in the polymer solution for 20 minutes to absorb the polymer. The panels were heated in a vented oven at 170 ℃ for 1.5 hours. Next, the panels were coated by placing the four sides and the back of the panel one after the other in the polymer solution for 20 minutes. Thereafter, the panel was heated again to 170 ℃ for 1 hour. All composite layers are approximately 8mm thick. The presence of the composite layers on all sides of the panel results in a panel that is very strong in all directions. Panels of different sizes have been made.

To investigate the effect of impregnating the panel dimensions on the panel compressive strength, panels were prepared as described above, except that only the sides of the panel were impregnated, not the top and bottom. The compression performance was tested using a Universal Testing Machine (UTM) (tensile, M350-20CT) equipped with compression plates. The panel with four impregnated sides showed an average compressive strength of 642N. The unimpregnated panel showed a compressive strength of almost 0. This indicates that impregnating the sides of the panel significantly improves the compressive strength of the panel.

Example 3: other uses of the panels

The panel according to the invention may be provided with internal stiffening or connecting means, such as beams or frames, to provide a ready-to-use self-supporting structure. Figure 3 shows an example in which a beam is introduced between two panels. Fig. 4 shows a self-supporting structure of a set of panels in a frame.

Example 4: other materials

Several other high void fraction mat materials are treated by the method of the present invention. The starting materials were two asbestos materials of different densities, glass wool, hemp mat and flexible open-cell polyurethane foam. The properties of the starting materials are shown in the table below.

In these examples, the polymer composition was used as described in example 1, except that 4.5 grams of glyceryl monostearate was added to the polymer composition to improve the adhesion of the polymer to materials with slightly hydrophobic character.

The mat was impregnated on one side according to the procedure described in example 1, followed by a single curing step. The samples were immersed for 20 minutes and then cured at 170 ℃ for 3 hours.

After the polyurethane mat was impregnated and cured, a good uniform 6mm thick composite layer was obtained. The composite layer is hard, strong, has a surface structure similar to that of an unimpregnated pad, and is very easy to work with, for example, by sawing and grinding. It is also well suited for the setting of screws.

The impregnated asbestos and glass wool samples also had a good uniform, odorless, relatively thin and hard composite layer. The mattress has a thicker (6mm) composite layer which is continuous but less uniform than the layers on other materials, which is associated with a rather uneven structure of the impregnated mattress.

Example 5: incorporating a covering layer

In one embodiment of the invention, a porous surface layer is applied on top of the panel before or during impregnation. This allows the manufacture of products with an attractive surface structure, and therefore may not require further finishing. In this example, example 1 was repeated except that the linen fabric was applied to the front surface after impregnation but before curing. A dry cloth is applied to the wet panel and the polymer is absorbed from the panel. The front surface of the final product has excellent visual and tactile properties. Furthermore, the presence of the cloth may result in an additional increase in the strength of the panel. Fig. 5 shows a panel obtained according to this embodiment.