JPH03124800A - Agent for forming leather-like surface layer - Google Patents

Abstract

PURPOSE:To improve the appearance, touch and moisture absorption/desorption by compounding a specific collagen powder with a synthetic resin binder. CONSTITUTION:Animal tissues treated with an alkali and washed with water according to a conventional method are dipped in water at pH8-10 containing a protease (e.g. papain), L-glutamic acid, a nonionic surfactant (e.g. alkylphenyl ether of polyethylene glycol), sodium chondroitin sulfate, etc., to remove separately fats, polysaccharides, proteins, etc., for purification. Then the animal tissues are adjusted to a pH2 to 5 before wet grinding, and are crosslinked in the presence of a crosslinking agent [e.g. Al2(SO4)3] to yield a collagen fiber agglomerate. The agglomerate is dehydrated to a water content of 70wt.% or below, dried and ground to give a collagen powder of a water absorbing power of 150-300wt.% and an apparent bulk density, of 0.10-0.30g/cc and having a particle content (for particles of 40mum or below in particle size) of 85wt.% or more. Then, 25-150 parts by weight of the collagen powder is added to 100 parts by weight of a synthetic resin binder.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Industrial Application Field The present invention relates to a novel leather-like surface forming agent. More specifically, seats, utensils, etc. have a natural leather-like appearance.

This invention relates to a leather-like surface layer forming agent suitable for imparting a texture.

(2) Conventional technology In recent years, as the appearance, feel, and functionality of vinyl chloride, artificial leather sheets, nonwoven fabrics, furniture, household electrical appliances, and other objects have become more sophisticated, is required to have. This leather-like surface layer formation was achieved in the past by applying a finishing agent containing synthetic resin such as polyurethane resin or polyacrylic resin as a binder and inorganic pigment such as silica as a matting agent to the surface of vinyl chloride, utensils, etc. In addition, the surface was processed with leather patterns such as grains, but this gives a leather-like appearance with gloss and patterns, but the first function is warmth, smoothness, and moisture absorption and desorption properties. etc., it did not look like leather at all. Recently, in order to meet this demand, a surface layer forming agent using leather fiber powder or leather powder obtained by crushing leather waste instead of the above-mentioned inorganic pigment has been developed.
It is used as a coating agent for automobile interior materials, architectural interior materials, furniture, precision equipment, etc. to provide performance similar to that of natural leather.

Several leather-like surface layer forming agents or methods for forming a leather-like surface as described above have been proposed, and the preceding examples include:
For example, JP-A-49-7405, JP-A-63-218
There are publications such as No. 286 and No. 63-236636. However, in JP-A-49-7405, the diameter of the collagen fibers is large, 80 mesh (180 μm).
), there are problems such as a complicated process when mixing this with a thermoplastic resin to produce a sheet-like artificial leather. In JP-A No. 63-236636, since the powder is a leather powder produced by simply crushing leather scraps, the crosslinking treatment is performed on the bare skin, and the crosslinking is not uniform on the leather fibers. Water absorption of powder (Since there is no standardized measurement method, it was measured by the method described below.

After immersing 1.0 g (WA) of the powder sample in water for over 1 hour to absorb water, drain the water thoroughly, sandwich it between blotting papers, and pressurize it with a press to a pressure of 10 to 4/am'' or more to remove excess water. removed, weighed (We), and calculated by the following formula % formula % () becomes less than 150% by weight, and
Apparent bulk density (JIS K 8721) is 0.30g
/cc, this leather-like surface layer-forming agent has drawbacks such as poor moisture absorption and desorption properties, and it cannot be said that it is still satisfactory for practical use.

Also, in JP-A-63-236636, like the above-mentioned publication, it contains leather powder, and the maximum particle size of this leather powder is 150 mesh (10゜μm), so a silky smooth feeling cannot be obtained. , moisture absorption and desorption properties are also poor, which is a problem.

(3) Problems to be Solved by the Invention The purpose of the present invention is to improve the above-mentioned problems of the prior art, and to apply vinyl chloride to the surfaces of sheets, furniture, utensils, etc. to give them properties similar to natural leather. The object of the present invention is to provide a leather-like surface layer forming agent that can be applied.

(4) Means for Solving the Problems As a result of various studies to achieve the above object, we found that in surface layer forming agents that use synthetic resin as a binder, the powder blended with the synthetic resin binder itself does not affect the feel of the leather. Based on the viewpoint that it is necessary to have similar properties, to have a smooth surface layer, and to have high moisture absorption and desorption properties, for example, it is necessary to have high moisture absorption and desorption properties. After purifying and wet-pulverizing animal tissue to make a collagen fiber dispersion, this is cross-linked with a cross-linking agent such as a chromium compound or a zirconium compound, and the resulting particles are produced by sequentially dehydrating, drying, and crushing, and the resulting particle size is 40 μm or less. (The particle size and particle size distribution of the powder were measured by the Coulter counter method.)
The content of particles is 85% by weight or more, and the water absorption is 1
50 to 300% by weight, and the apparent bulk density is o, io
The present invention was completed by discovering that a leather-like surface layer forming agent can be obtained by using collagen powder having a concentration of ~0.30 g/cc.

The leather-like surface layer forming agent of the present invention is a synthetic resin binder mixed with collagen powder for the purpose of imparting a leather-like appearance, feel and function, and it imparts smoothness to the surface of the substrate to which it is applied. It is characterized by the fact that it has high moisture absorption and desorption properties and moisture absorption rate, and forms a leather-like surface layer with properties similar to those of natural leather. This collagen powder smoothes the leather-like surface layer formed on the surface of a base material such as vinyl chloride, giving it a smooth feel.
In order to increase moisture absorption and desorption, the water absorption is set at 150 to 300% by weight, and the apparent bulk density is set to 0.10'' to increase the rate of moisture absorption and desorption. 0.301/cc.The smaller the particle size of the collagen powder is, the better for the purpose of smoothing the surface layer, but if it is 40 μm or more and 15% by weight or less, it is sufficient to achieve the purpose.40 μm or more is If it exceeds 15% by weight, the smoothness of one surface will be lost, which is not preferable.

The higher the water absorption, the better in order to improve moisture absorption and desorption properties, but 300
If it is so high as to exceed 150% by weight, the volume of the powder increases more than necessary due to water absorption, which reduces the strength of the surface layer, which is undesirable.If it is less than 150% by weight, sufficient moisture absorption and desorption effects cannot be obtained. Since there is no such thing, it is not practical. The smaller the apparent bulk density, the better in order to increase the rate of moisture absorption and desorption, but if the groove is not 0.10z/cc, dust will easily be generated.
In addition, it is difficult to mix with a binder, so it is not suitable for practical use. Moreover, if it exceeds 0.30 g/cc, the rate of moisture absorption and desorption will decrease significantly, which is not preferable.

There are no particular restrictions on the production of the collagen fine powder to be incorporated into the leather-like surface layer forming agent of the present invention, but it may be prepared, for example, by the following method, but of course it may be produced by other methods. It's okay.

That is, for example, it is produced by sequentially subjecting animal tissue such as animal skin to purification, wet grinding, crosslinking, dehydration, drying, and grinding. This animal tissue includes the skin of all kinds of animals, including mammals such as cows, horses, pigs, and sheep.
Tissues containing a large amount of collagen, such as bones and rhinoceros, can be used.

In the purification process, the above animal tissue is treated with alkaline using a normal method and then washed with water. Using protease enzymes, fat, polysaccharide, and protein, which are impurities other than collagen, are separated and removed from the animal tissue. This process produces purified collagen. As the protease enzyme, at least one type from pancreatic trypsin, papain, pancreatin, Bacillus mycelia alkaline protease, etc. is used for normal leather purification, but for the leather-like surface layer forming agent of the present invention, In order to improve heat resistance and light resistance, it is preferable to use collagen powder from which the impurities mentioned above are almost completely removed. For this purpose, for example, papain and pancreatin are used, and furthermore, these enzymes are used. In order to enhance the function and increase the efficiency of separating and removing impurities,
The pH is adjusted to 8 to 1o using sodium hydrogen carbonate and/or quaternary ammonium salt or hydroxide, and as an auxiliary agent, L-glutamic acid, L-fi potassium hydrogen acetate nonionic surfactant, Sodium chondroitin sulfate, etc. are used in combination. A specific example of a nonionic surfactant is Triton X-10, which is an alkyl phenyl ether of polyethylene glycol with a high HLB.
0 (manufactured by Kishida Chemical Co., Ltd.).

Wet milling is used to stabilize the properties of the collagen powder produced, and to ensure that the crosslinking treatment that follows this treatment is easy and uniform, the purified collagen is This is a process in which a lump is swollen with water to form a dispersion of collagen fibers or a solution of collagen molecules. As a pretreatment, the pH is adjusted to 2 to 5 using lactic acid or the like, and the meat is coarsely ground using a meat grinder, and then it is carried out using equipment such as a beater or a rotary blade crusher. In addition, the concentration of collagen fibers or molecules at this time is 0.2-6 to prevent the collagen from changing into gelatin and to suppress the temperature rise due to friction between collagen fibers during wet grinding.
．． Preferably, it is 0% by weight.

Crosslinking treatment is a process in which a crosslinking agent is added to a dispersion of collagen fibers or a solution of collagen molecules to link fibers or molecules in order to maintain the water absorption of collagen powder at a predetermined value and increase heat resistance. It is. Examples of the crosslinking agent include inorganic compounds such as chromium sulfate, zirconyl sulfate, zirconium sulfate, and aluminum sulfate, and organic compounds such as formaldehyde, glutaraldehyde, and tannin, and it is also possible to use two or more of these. The amount of crosslinking agent added per 100 parts by weight of collagen fibers or molecules to make the water absorption of collagen powder 150 to 300% by weight is 1 to 2 parts by weight for chromium sulfate, and 1 to 10 parts by weight for zirconyl sulfate and zirconium sulfate. Suitable parts by weight are 2 to 20 parts by weight for aluminum sulfate, 1 to 2 parts by weight for formaldehyde and glualdehyde, and 2 to 5 parts by weight for tannin. In addition, in order to make the appearance of the produced powder white or to make the surface layer forming agent transparent, it is preferable to use zirconyl sulfate, zirconium sulfate, or aluminum sulfate.

The dehydration treatment is carried out using a conventional centrifuge, filter press, screw press, etc. in order to lower the moisture content of the collagen fiber aggregates obtained through the crosslinking treatment, making drying easier and reducing the load. made using. The moisture content is preferably 70% by weight or less.

The drying process uses a fluidized type, tray type, paddle type dryer, etc. for the purpose of further lowering the moisture content of the wet collagen that has become lumpy due to the dehydration process and making it easier to crush. The moisture content is preferably 10% by weight or less.

In the crushing process, the collagen fiber mass obtained in the drying process is
This is done using a conventional jet mill, hammer mill, ball mill, etc. in order to obtain 85% by weight or more of particles having a particle diameter of 40 μm or less.

The particle size of the powder is preferably close to a normal distribution, with an intermediate diameter of 4 to 25 μm and a maximum diameter of 63 μm (235 mesh passes).

Collagen powder produced in this way differs from conventional leather powder obtained by simply grinding leather produced by cross-linking purified naked skin as it is, but collagen powder is produced by wet grinding. Once the fibers have been completely defibrated or molecularized, they are cross-linked, resulting in a cross-linked body of uniformly aggregated fine fibers, forming a network structure of fine fibers, and forming particles. There are voids inside. As a result, the apparent bulk density is smaller than that of conventional leather powder, ranging from 0.10 to 0.30 g/cc, and the specific surface area is also increased. Similarly, water absorption is also high.

The leather-like surface layer forming agent of the present invention is prepared by blending the above collagen powder with a synthetic resin binder. Examples of the synthetic resin binder include polyurethane resin, acrylic resin, polyester resin, polyvinyl chloride resin, epoxy resin, etc. A solution prepared by diluting a synthetic resin with a solvent is suitable. The binder and collagen powder can be mixed by dispersing the collagen powder in a solvent used for the binder and then mixing with the binder, or by dispersing the collagen powder directly into the binder and mixing. Hydrocarbons such as toluene and xylene are used as solvents.

Ketones such as methyl isobutyl ketone and cyclohesisanone, esters such as ethyl acetate and butyl acetate, and the like can be used. The blending ratio of the binder resin and the collagen powder is preferably 25 to 150 parts by weight of the collagen powder per 100 ffi parts of the binder resin. In addition to the synthetic resin binder and collagen powder, it is also possible to change the color scheme and feel by combining pigments such as titanium dioxide and carbon black, extender pigments such as kaolin and talc, and matting agents such as silica. Furthermore, it is possible to enhance the leather-like appearance by applying a textured pattern to the surface.

(5) Effect The leather-like surface layer forming agent of the present invention can be applied to the surface of a film made of polyvinyl chloride or the like applied to a sheet of polyvinyl chloride resin, nonwoven fabric, or knitted fabric using a coating machine such as a gravure coater. Alternatively, use a coater to coat a release paper with a textured pattern, etc., apply a nonwoven fabric or knitted fabric to this, and then peel off the surface layer forming agent to create PVC leather or artificial leather. It can also be applied as a paint to the surfaces of utensils, molded objects, etc. using a spray gun, coater, etc. PVC leather, artificial leather, and paint have the appearance, feel, moisture absorption and desorption properties of natural leather, and are highly heat and light resistant. In addition, since the smoothness of the formed surface layer differs depending on these uses, the preferred particle size of the collagen powder blended into the surface layer forming agent is 85% by weight or less of 40 ILm or less for PVC leather or artificial leather, The diameter is 25 μm or less, but in the case of paint, 95% by weight or more is 40 μm or less, and the intermediate diameter is 15 μm or less.

(6) Example 1 Example 2 1) Production of collagen powder A, purified treatment: 500 parts by weight of cow's skin washed with water after alkali treatment with lime (dry weight is 100 parts by weight, hereinafter, parts by weight are parts). ) was soaked in the following treatment solution whose pH was adjusted to 8.1 with sodium bicarbonate, and papain was added.
0.60 parts Pancreatin 0.15 parts L Glutamic acid 0.35 parts Sodium chondroitin sulfate 0.003 parts Potassium bitartrate 0.35 parts Triton x
-i o o o, so part water
Contaminants were removed by stirring in a 5,000-part domestic washing machine at room temperature for 12 hours, and after washing with water, the product was soaked with lactic acid to adjust the pH to 4.0 to obtain a purified collagen tissue.

B. The collagen tissue obtained by @-type grinding process A is minced using a meat grinder, and the dry weight concentration of the original bed skin is 0.66%.
Dilute with water so that 3. P and H are added with lactic acid.
2 and wet-pulverized using a paper mill.

After C0 crosslinking treatment and wet pulverization, the following crosslinking agents were sequentially added in a paper beating machine to carry out crosslinking treatment using 4.5 parts of aluminum sulfate and 2.5 parts of zirconyl sulfate to obtain collagen fiber aggregates.

D. Dehydration, drying, and pulverization process The collagen fiber aggregate obtained in C was dehydrated using a screw press dehydrator until the moisture content reached 67% by weight, and then dried using a hot air tray dryer. to reduce the moisture content to 9
．． 5% by weight and further crushed using a hammer mill and having the physical properties shown in Table 1, 2 types of collagen powder a,
b.

2) Production of surface layer forming agent and application to base material E, application to iron plate Add 50 parts of the collagen powder obtained in 1) to a binder prepared by dissolving 100 parts of polyurethane resin in 200 parts of ethyl acetate and titanium dioxide 2 as a pigment. part, carbon black 8
of the mixture and dispersed well to form a leather-like surface layer forming agent. Furthermore, this surface layer forming agent was applied to the surface of the iron plate using a spray gun so that the thickness of the surface layer after drying was 50 μm, and dried to obtain an iron plate on which a leather-like surface layer was formed. .

F. Application to plastic plate 50 parts of the collagen powder obtained in 1) was added to a binder prepared by dissolving 100 parts of polyurethane resin in 200 parts of ethyl acetate, and the mixture was well dispersed to obtain a leather-like surface layer forming agent. Furthermore, this surface layer forming agent was applied to the surface of a transparent polycarbonate plate using a spray gun so that the thickness of the surface layer after drying was 50 μm, and then dried to form a plastic with a leather-like surface layer. Got the board.

G. Application to polyvinyl chloride sheet 60 parts of the collagen powder obtained in step 1 and 10 parts of carbon black as a pigment were added to a binder made by dissolving 100 parts of polyurethane resin in 200 parts of ethyl acetate, and the mixture was well dispersed to form a leather-like surface. It was used as a layer forming agent. Furthermore, this surface layer forming agent was applied to the surface of the polyvinyl chloride sheet using a gravure coater so that the thickness of the surface layer after drying was 30 μm, and dried to form a leather-like surface layer. I got PVC leather.

3) Surface layer test The samples with leather-like surface layers obtained in 2) E, F, and G were tested for the items listed in Table 1, and the results shown in Table 1 were obtained.

``Dr. L''.

1) Production of collagen powder A: 500 pieces of cow bedding skin that has been treated with alkali using purified lime and washed with water.
Part by weight (dry amount is 100 parts by weight, hereinafter, parts by weight is abbreviated as parts) is added to the following treatment solution whose pH was adjusted to 9.0 with 0.05 part of tetramethylammonium hydroxide and sodium bicarbonate. pickled, papain
0.55 parts pancreatin 0.15 parts L
Glutamine a O, 30 parts Sodium chondroitin sulfate 0.002 parts Potassium hydrogen bitartrate 0.30 parts Triton X-
1000,50 parts water 5ooo
Remove impurities by stirring in a household washing machine at room temperature for 12 hours, and after washing with water, acidify with lactic acid to adjust the pH to 3.2.
and purified collagen tissue was obtained.

B. The collagen tissue obtained in wet grinding treatment A is minced using a meat grinder, and the dry weight concentration of the thick skin is 0.80%.
The mixture was diluted with water so that the pH was adjusted to 2.8 with lactic acid, and the mixture was wet-pulverized using a paper mill.

C0 crosslinking treatment After wet grinding, the following crosslinking agents were sequentially added in a paper beating machine.

Aluminum sulfate 265 parts Zirconium sulfate 3.0 parts A softened collagen fiber aggregate was obtained by crosslinking treatment.

D. Dehydration, drying, and pulverization process The collagen fiber aggregate obtained in C was dehydrated using a screw press dehydrator until the moisture content reached 67% by weight, and then dried using a hot air tray dryer. and reduce the moisture content to 5
．． The collagen powder was reduced to 0% by weight and further ground using a hammer mill to obtain collagen powder having the physical properties shown in Table 1.

Hereinafter, the production of the surface layer forming agent and the base material (
Application to (E, iron plate; F, plastic plate; G, polyvinyl chloride sheet) and surface layer tests were conducted, and the results shown in Table 1 were obtained.

,L! u11 (Surface layer forming agent using powder with large particle size) In the pulverization process of Example 2, the particle size of 40 μm or less was
Producing a surface layer forming agent, applying it to a substrate (E, iron plate, F, plastic plate, G, polyvinyl chloride sheet) and testing the surface layer in the same manner as in Example 1 using collagen powder expressed as % by weight. The results shown in Table 1 were obtained.

1Lf12 (Surface layer forming agent using leather powder) 1) Production of leather powder
110°C for 3 hours in an autoclave with heated steam
heated and swollen, dried and pulverized in the same manner as in Example 1 to obtain the first
Leather powder having the physical properties shown in the table was obtained.

Hereinafter, the production of the surface layer forming agent and the base material (
Application to (E, iron plate; F, plastic plate; G, polyvinyl chloride sheet) and surface layer tests were conducted, and the results shown in Table 1 were obtained.

From the results shown in Table 1, the leather-like surface layer-forming agent of the present invention has excellent color tone and feel, and has excellent absorbency when used on any substrate to be coated, compared to conventional leather-like surface layer-forming agents. Moisture release properties as well
The water absorption is higher than the practically necessary level of 2,501/m2, and the moisture release rate is also 15.0 mg.
/m2·sec.

(7) Effects of the Invention According to the present invention, the water absorption is 150 to 300% by weight and the apparent bulk density is 0.10 to 0.30 g/. .

Using this fine particle collagen powder, a leather-like surface forming agent with good appearance, good feel, and excellent moisture absorption and desorption properties can be obtained regardless of the substrate to which it is applied.

Claims (2)

[Claims] (1) A surface layer forming agent using a synthetic resin as a binder, characterized in that the content of particles with a particle diameter of 40 μm or less is 85% by weight or more, and contains collagen powder with a water absorption of 150 to 300% by weight. A leather-like surface layer forming agent. (2) The apparent bulk density of collagen powder is 0.10 to 0.
．． The leather-like surface layer forming agent according to claim 1, which is 30 g/cc.