JPH03195800A - Leather-like molding - Google Patents

Abstract

PURPOSE:To obtain the subject molding capable of giving natural leather-like characteristics to an article such as a handle for a bicycle and a grip of a sports goods and a formed material such as a sheet, a furnishing and a bag by blending collagen powder having specified physical properties with a thermoplastic resin and carrying out melt molding thereof. CONSTITUTION:(A) Collagen powder having >=85wt.% content of particles of <=40mum particle size, 150-300% water absorption and 0.10-0.30g/cc apparent specific gravity in an amount of 2-70wt.% (preferably 5-60wt.%) is blended with (B) a thermoplastic resin such as PE, PP, PS, polyamide, polycarbonate or urethane rubber and the resultant mixture is subjected to melt molding, thus obtaining the objective molding.

Description

Detailed Description of the Invention (1) Industrial Application Field The present invention relates to a novel leather-like molded product, and more specifically, it is applicable to parts such as automobile handles, grips of sports equipment, seats, furniture, and bags. The present invention relates to a leather-like molded product made of collagen powder such as the above and a thermoplastic resin.

(2) Conventional technology In recent years, with the trend toward luxury, sheets, non-woven fabrics, furniture, automobile steering wheels, and other parts made of vinyl chloride, artificial leather, etc. have the appearance, feel, and functionality of natural leather. requested. Conventionally, the above-mentioned automobile parts and furniture with a leather-like appearance have been made of molded products such as synthetic resin, molded products of steel, aluminum, etc. with leather pasted on them, or leather pasted on the surface of wood, etc. Many of them were made up of things that were done. However, as mentioned above, the leather is expensive and the pasting process is time-consuming, so the cost is high.Also, the elasticity of the leather and the underlying fabric is different depending on the temperature, so the fabric may shrink. There were problems such as the edges of the leather being exposed and the leather peeling off, making it unsightly.

In order to solve these points, Japanese Patent Application Laid-Open No. 62-24040
No. 0, JP-A-63-11311, JP-A-63-
As proposed in Japanese Patent No. 22864, etc., leather powder and thermoplastic resin are mixed and molded to obtain a leather-like molded product. However, the above-mentioned leather-like molded products are made of leather powder in the form of fibers or lumps with cilia, which are relatively coarse powders, and when incorporated into a thermoplastic resin, they aggregate and cannot be uniformly dispersed. It is difficult and has low fluidity; 1. Products with smooth surfaces or thin products cannot be obtained; and 1. Ordinary leather powder has a high oil and fat content, so when a resin containing it is heat-molded, heating may generate an odor. , causing discoloration. Since the leather powder itself has low hygroscopicity, the resulting molded product also has low hygroscopicity. Also.

During hot molding, oil and fat bleed onto the surface of the molded product, causing a sticky feeling and contamination, as well as deteriorating its moisture absorption properties.

Therefore, as proposed in JP-A-1-197599, a leather-like molded product is obtained by mixing and molding leather powder with a low oil and fat content and a resin. However, the particle size is still too large to provide a smooth and smooth feeling, and the matting effect is also low, so it is difficult to say that it is still satisfactory for practical use.

(3) Problems to be Solved by the Invention An object of the present invention is to improve the problems of the prior art described above, and to improve parts such as automobile handles, grips of exercise equipment, seats, etc.
To provide a leather-like molded article made of collagen powder and a thermoplastic resin, which can impart properties close to natural leather to molded articles such as furniture and bags.

(4) Means for Solving the Problems According to the present invention, the content of particles having a particle diameter of 40 μm or less is 85% by weight or more, and the water absorption is 150 to 300%.
A leather-like molded article is provided which is comprised of a collagen powder and a thermoplastic resin in the same proportions by weight.

In the present invention, the powder mixed with the resin itself is
Based on the viewpoint that it is necessary to have leather-like properties in terms of feel, smooth surface layer, and high moisture absorption, we have developed collagen such as the skin of pigs, cows, etc. Particles produced by purifying and wet-pulverizing a large amount of animal tissue to produce a collagen fiber dispersion, which is then cross-linked with a cross-linking agent such as a chromium compound or zirconium compound, followed by -Mt water, drying, and pulverization. The diameter is 40 μm or less (
The particle size and particle size distribution of the powder were determined by the Coulter Counter method). The present invention was completed by discovering that a leather-like molded article can be obtained by using collagen powder having a concentration of .30 g/cc. Since there is no standardized method for measuring the water absorption of the powder, it was measured using the method described below. After soaking 1.0 g (WQ) of the powder sample in water for over 1 hour to absorb water, drain the water well, and then sandwich it between blotting papers and pressurize it to 10 kg/c or more with a press to remove excess adhering water. Then, use the scale Jl (W day) and use the following formula % formula %
Calculated using ().

In order to smooth the surface layer of the molded product and give it a smooth feel, this collagen powder contains less than 15% by weight of particles with a particle diameter of 40 μm or more, and has a water absorption rate of 150 to 300 to improve moisture absorption and desorption properties. In addition, in order to increase the rate of moisture absorption and desorption, the apparent bulk density is set to 0.10 to 0.10.
It was set to 0.301/cc. The particle size of the collagen powder is preferably as small as possible for the purpose of smoothing the surface layer, but if the particle size is 40 μm or more and less than 15% by weight, it is sufficient to achieve the purpose. If the amount of particles with a diameter of 40 μm or more exceeds 15% by weight, the surface smoothness will be lost, which is not preferable. The higher the water absorption, the better in terms of improving moisture absorption and desorption properties, but if it is so high as to exceed 300% 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 not preferable. If it is less than 150% by weight, sufficient hygroscopic effect cannot be obtained, so it is not practical.The smaller the apparent bulk density is, the better in order to increase the rate of moisture absorption and desorption, but 0.101
/cc If the groove is not formed, dust is likely to be generated and mixing with the binder becomes difficult, so it is not suitable for practical use. Also.

If it exceeds 0.30/ec, the rate of moisture absorption and desorption will drop 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 molded article of the present invention, but for example, it may be prepared by the following method, but of course it may also be produced by other methods. good.

That is, for example, it is produced by sequentially subjecting animal tissue such as animal skin to purification, wet grinding, crosslinking, aqueous treatment, 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 vaginas, can be used.

Purification treatment: 1) Alkali treatment using the usual method.

The washed animal tissue is treated with a protease enzyme to separate and remove impurities other than collagen, such as fat, multi-tasties, and protein, from the animal tissue to obtain purified collagen. be. As protease enzymes, at least one enzyme is used from pancreatic trypsin, papain, vancreatin, Bacillus alkaline protease, etc. for normal leather purification. In order to improve the properties and light resistance, it is preferable to prepare a collagen powder from which the above-mentioned impurities have been almost completely removed. For this purpose, for example, papain and pancreatin are used. In order to increase the efficiency of separation and removal of impurities, the pH is adjusted to 8 to 10 using sodium hydrogen carbonate and/or quaternary ammonium salt or hydroxide, and L-glutamic acid is added as an auxiliary agent. , potassium L-bitartrate, a nonionic surfactant, sodium chondroitin sulfate, etc. are used in combination. A specific example of a nonionic surfactant is Triton X-100 (alkyl phenyl ether of polyethylene glycol with high HLB).
Kishida Chemical It).

Wet milling is a purification process to make the properties of the produced collagen powder constant, and to make the crosslinking process that follows this process easy and uniform. This is a process in which a lump of collagen is swollen with water to form a dispersion of collagen fibers or a solution of collagen molecules. As a pre-treatment, the pH is adjusted to 2~2 using lactic acid etc.
5 and coarsely ground using a meat grinder, then beaten.

This is done using equipment such as a rotary blade crusher. In addition, the concentration of collagen fibers or molecules at this time is set to 0.00 to prevent collagen from changing into gelatin and to suppress temperature rise due to friction between collagen fibers during wet grinding.
The content is preferably 2 to 6.0% 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% is 1 to 2 parts by weight for chromium sulfate, and 1 to IO 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 first 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. This is done in a conventional manner. 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.

Unlike conventional leather powder, which is obtained by simply pulverizing leather that is produced by cross-linking raw skin after purification, collagen fibers are completely decomposed or molecularized by the 1m type pulverization process. After that, a crosslinking treatment is performed, resulting in a crosslinked body of uniformly aggregated m-fibers, forming a network structure of m-fibers gathered together, and voids are observed within each particle. As a result, the apparent bulk density is smaller than that of conventional leather powder, ranging from 0.10 to 0.301/cc.
The specific surface area also increases. Similarly, water absorption is also high.

Thermoplastic resins to which the collagen powder of the present invention is blended include polyethylene (low-density polyethylene, high-density polyethylene, linear low-density polyethylene, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer), polypropylene Synthetic resins such as polyolefin, polybutadiene, polystyrene, ABS resin, AC8 resin, polyvinyl chloride (including those containing plasticizers), polyamide, polycarbonate, etc. are used. Furthermore, various rubbers such as urethane rubber and ethylene-propylene-diene rubber can also be used.

If necessary, the resin can be used as a resin compound by containing plasticizers, stabilizers, curing agents, catalysts, fillers, colorants, 1 reactive monomer, solvents, 1 dispersant, and various other additives. can. Moreover, it may be a side body or a liquid.

The blending ratio when blending collagen powder with Wsn to make a resin composition is determined depending on the use, shape, requirements, etc. of the molded product obtained by molding the resin composition. Or the resin compound is 30-98% by weight, preferably 40-95% by weight, and the collagen powder is 2-70% by weight.
If the amount of collagen powder is less than 2% by weight, leather-like properties will not be obtained, and if it is 70% by weight or more, resin-like properties will not be obtained. This is not preferable because it becomes impossible to uniformly disperse the material and the physical properties such as strength and abrasion properties are greatly reduced.

The resin composition thus obtained is processed by 1. ordinary melt molding, that is, by injection, using a thermoplastic resin that softens and melts when heated, can be deformed arbitrarily by applying force, and solidifies when heat is removed. Hollow.

Calender Performs extrusion processing and molds to obtain leather-like molded products.

The collagen powder used in the present invention is finer than conventional particles with a content of 85% by weight or more of particles with a particle size of 40 μm or less, and has very good miscibility with a thermoplastic resin compound. mold machine cylinder
Since the contact resistance with the screw and die is similar between the thermoplastic resin compound and the collagen powder, extrusion during molding is performed smoothly, and the machine is not damaged due to changes in injection pressure, resulting in a uniform, high-quality leather-like product. A molded article can be obtained.

(5) Function The leather-like molded product of the present invention is molded by mixing collagen powder with a thermoplastic resin in order to give it a leather-like appearance, feel, and function. It has properties similar to natural leather, with high moisture absorption and desorption properties and speed. Because of its excellent feel, the leather-like molded product obtained by the present invention is a flexible film.

Widely used for seats, chair armrests, furniture, console boxes, handle grips, etc.

(6) Examples The present invention will be explained in more detail with reference to Examples and Comparative Examples below, but it is of course not limited to these.
In the Examples and Comparative Examples, "parts" indicate "parts by weight" unless otherwise specified.

1 bonito”.

1) Production of Collagen Powder A: Purification Process: 500 parts by weight (dry weight: 100 parts by weight) of cow's hide, which has been washed with water after alkaline treatment with lime, is prepared by adjusting the pH to 8.1 with sodium bicarbonate. Soaked in processing solution.

Papain O, a O parts Pancreatin 0.15 parts L glutamic acid
0.35 parts chondroitin iu + t sodium 0.003 parts potassium hydrogen bitartrate 0.35 parts Triton X
-1000, 50 parts water 5000
After stirring in a household washing machine at room temperature for 12 hours to remove impurities, washing with water, acidifying with lactic acid to adjust the pH to 4.0.
and purified collagen tissue was obtained.

B. The collagen tissue obtained by the l1 type grinding process A was minced using a meat grinder, and the dry weight concentration of the original bed skin was 0.66%.
The mixture was diluted with water so that the pH was adjusted to 3.2 with lactic acid, and the mixture was wet-pulverized using a paper mill.

After C0 crosslinking treatment and wet pulverization, the following crosslinking agents were sequentially added in an m-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 The collagen fiber aggregate obtained in step C was dehydrated using a screw breath 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
．． The mixture was bound to 5% by weight and further ground using a hammer mill to obtain two types of collagen powders a and b having different particle sizes and physical properties as shown in Table 1.

2) Manufacture of molded product E, formulation example I LLDPE (Wrinkled Rex Linear: MI=23g/
For 10 minutes, 80% by weight (density 0.916 g/cm3) and 20% by weight of the collagen powder of Example 1 were melt-kneaded in a mixer at 180°C, and then a 0.8 mm sheet was formed by compression molding.

F, Formulation example 2 Vinyl chloride resin (Shin-Etsu Chemical @ TK-1300) 10
A resin composition consisting of 0 parts of dioctyl phthalate, 90 parts of dioctyl phthalate, and 80 parts of the collagen powder of Example 1 was made into a 0.5 mm sheet by a calendering method.

3) Test of surface layer The samples of the leather-like molded products obtained in steps E and F of 2) were tested for the items listed in Table 1, and the results shown in Table 1 were obtained.

Flame Chogoyu ■) Production of collagen powder A, 500% of cow bedding skin treated with alkali with 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 Bankcreatin 0.15 parts L glutamic acid
0.30 parts Sodium chondroitin sulfate o, oz parts Potassium hydrogenbitartrate 0.30 parts Triton X
-1000, 50 parts water 5000
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.

8. The collagen tissue obtained by Type 11 grinding process A was minced using a meat grinder, and the dry weight concentration of the original bed skin was 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.

After C0 crosslinking treatment and wet grinding treatment, the following crosslinking agents were sequentially added in a paper mill to obtain a softened collagen fiber aggregate.

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
．． 0% by weight, and was further ground using a hammer mill to obtain collagen powder having the physical properties shown in Table 1.

Thereafter, molded articles were manufactured in the same manner as in Example 1 (E, Formulation Example 1; F, Formulation Example 2), and tests on the surface layer were conducted, and the results shown in Table 1 were obtained.

2 (Molded product using powder with large particle size) A molded product was made in the same manner as in Example 1 using the collagen powder in which 72% by weight of the particle size was 40 μm or less in the crushing process of Example 2. Manufacture (E, Formulation Example 1, F, Formulation Example 2),
Tests on the surface layer were carried out with the results shown in Table 1.

Ku Shibori Goyu (molded product using leather powder) 1) Production of leather powder After shredding leather scraps with normal chrome binding, heating and swelling them in an autoclave with heated steam for 3 hours. It was dried and crushed in the same manner as in Example 1 to obtain leather powder having the physical properties shown in Table 1.

Hereinafter, molded products were produced in the same manner as in Example 1 (E, Formulation Example 1, F, Formulation Example 2), one surface layer was tested, and the first
The results shown in the table were obtained.

From the results in Table 1, the leather-like molded product of the present invention.

Compared to conventional leather-like molded products, both thermoplastic resins have excellent appearance and feel, and moisture absorption and desorption properties are lower than 2°50 l-2, which is the level required for practical use. The moisture release rate is also 15.0m per 15.0m.
It is shown that it is larger than lI2·set.

(7) Effects of the invention According to the present invention, the content of particles with a particle diameter of 40 μm or less is 85% by weight or more, the water absorption is 150 to 300% by weight, and the apparent bulk density is 0.10 to 0.30 g/ A leather-like molded article with good appearance, feel, and excellent absorption and release properties can be obtained by using collagen powder with fine particles of cc and by using any thermoplastic resin.

Claims (1)

[Scope of Claims] Collagen powder containing 85% by weight or more of particles with a particle size of 40 μm or less and a water absorption of 150 to 300% by weight is mixed with a thermoplastic resin and melt-molded. Characteristic leather-like molded products.