JPH01110600A - Molding of leather powder - Google Patents

Abstract

PURPOSE: To obtain leather material powder which is free of entanglement and discoloration by degreasing the leather material powder or slices subjected to a tanning treatment, then subjecting the powder or slices to heating and swelling treatment, followed by pulverizing in a force dry state.

CONSTITUTION: The lipid materials of leather materials, such as shaving scrap, subjected to the chrome tanning treatment, etc., then to cutting or pulverizing, are eluted by a solvent, such as toluene or methyl chloride, and are thereafter subjected to steam heating, by which the leather materials are sufficiently swollen and the shrinking out of the tissue is induced. The remaining lipid materials are further extracted and the treating solvents are sufficiently removed. The leather material is dried again and is pulverized by a pulverizing machine, such as a fine victory mill, by which the objective leather powder is obtd.

COPYRIGHT: (C)1989,JPO

Description

[Detailed Description of the Invention] (Field of Application in Industry-1-) This invention grinds naturally existing leather into fine powder under certain processing conditions, and uses the ground leather powder in the form of fine powder. The purpose is to provide various grass-like molded products with characteristics closer to those of natural leather, and in particular, by pulverizing the leather powder used, removing as much of the lipids contained in this leather powder as possible, and degreasing. By effectively removing the solvent, this leather powder can be used in combination with polyurethane resin to create various leather-like molded products, sheets, films, paint films, or coatings that have characteristics closer to natural leather. It is intended to provide services.

(Prior Art) The present applicant has already disclosed in a number of patent applications a method for grinding leather, a method for utilizing the acid powder in the ground leather, and an improvement in the properties of the leather powder provided by the grinding.

Among these series of applications, the present applicant has continued to develop peel/six powder having the following properties.

It has been successfully commercialized.

In order to eliminate the inconveniences associated with leather powder products, which are produced only by mechanical and physical crushing such as hammer type, as part of molding and semi-immersion of leather I6 powder, the leather is thoroughly immersed in steam before being crushed. The apparent specific gravity of the leather is increased by the Kaya method, in which the leather is swollen, the tissue is weakened by this swelling, and then the leather is crushed.

In this way, by increasing the apparent specific gravity and making the apparent specific gravity of the leather 1/i powder within the range of 0.38 to o, sO (g/cc), the pulverized leather powder Mutual entanglement was prevented, and mixing with resin fabric etc. was made possible.

As a result, the apparent appearance of leather powder with a specific gravity of 0.38 to 0.50 (g/cc) when the moisture content was 3% by weight or less was 4%.
Even in the case of unique ultrafine leather powder, such as one that is sorted with a 0 mesh sieve and classified with an air separator, and the amount of leather powder that is smaller than 40 microns is 70JRffi% or more, the leather powder cannot be mixed with each other. No more tangles.

Therefore, it is possible to use this leather powder to mold various resin molded products, sheets, films, etc., or to mold coatings or transfer films, or mix it into paints and use it to mold paint films. All of them had the advantage that the mixed leather powder did not become tangled in a flocculent manner and was scattered on the resin fabric etc. without a whirlpool layer.

Also, in this way, it is mixed into resin fabrics, paints, etc. without a swirl layer,
In addition, it has sufficient lubricity, so it has the characteristic that the characteristics of the mixed skin I6 powder can be fully brought to molded resin products, films, sheets, coated or transferred coatings, or painted coatings. Was.

(Problem to be solved by the invention) However, the apparent appearance on the slope has a specific gravity of 0.38 to 0.50.
(g/cc) when used with resin or paint, the leather powder may turn yellowish brown, resulting in unexpected color development or discoloration on the surface of the molded product or formed coating. found.

Such inconveniences occur particularly when the molded product is of a white or thin plain color, and countermeasures have been required. It has also been pointed out that the surface of a molded article or painted film that has undergone such discoloration tends to feel slightly sticky to the touch.

Therefore, the present applicant extracts the lipids contained in finely powdered leather powder using a degreasing solvent such as toluene and methyl chloride to extract the lipids contained in the leather powder. We have tried to remove as much of the lipids as possible.

However, this method has the disadvantage that the lipids in the leather powder cannot be sufficiently removed, and toluene is present in the leather powder.
This causes the inconvenience that degreasing solvents such as methyl chloride remain, which impairs the softness characteristic of crushed leather powder, and when used with resin or paint, there is the inconvenience that the surface of the molded product or paint film changes color. It was left behind.

(Means for solving the problem) The molding method of leather/6 powder used for leather-like molded products etc. related to undeveloped Ill retains the advantages of the conventional leather powder on the slope, but causes the above-mentioned discoloration. This is the ultimate source of leather powder.

First, shaving waste, etc., which has been subjected to chrome treatment and has already been cut or crushed, is used to elute the lipids in the vinegar material using a solvent, such as toluene or methyl chloride, that has lipid elution properties.

The elution of such lipid substances does not necessarily require the elution of all the lipid substances contained in the sealing material, and it is sufficient that the powder is eluted by these lipid substances to the extent that the powder does not change color.

Next, vinegar material that has been treated to elute the lipids on the slant is placed in the processing chamber, and steam is supplied to the borrowed goods placed in the processing chamber. The vinegar material is sufficiently swollen by this air heating, loosening the entanglements between the collagen fibers, and causing the tissue to shrink. At the same time, the remaining lipids are further extracted. Toluene, 11
! Thoroughly remove processing solvents such as methyl chloride.

The leather that has been subjected to the oil and fat elution treatment and the steam heating treatment is dried again and then crushed using a crusher such as Fine Victory Mill to produce a fine powder that does not tangle and does not discolor. No leather powder is obtained.

(Function) In the method for forming leather powder according to the present invention, the lipids contained in the vinegar material are largely removed with a degreasing solvent such as toluene or methyl chloride, and then steam heat treatment is performed. As a result, residual lipids can be more smoothly eluted, and by this steam heat treatment, degreasing solvents such as toluene and methyl chloride are removed by volatilization without remaining in the molded leather powder.

(Example) A typical embodiment of the present invention will be described below.

First of all, the leather material used may be cowhide, sheepskin, pigskin, etc. (1) Shaving ifl treated with chrome is usually used, but it may also be tanned leather. .

These leather materials are usually 8.5z for sheepskin and 6.5z for steer skin.
8z, horsehide contains lipids after 10.5i 1ifj, so this leather material is cut into appropriate sizes (or pulverized in the case of shaving waste) or crushed, and then soaked in vinegar. The material is dried so that the moisture content in the material is within 5% by ERW, and then poured into a degreasing solvent such as methyl chloride or toluene and stirred to extract the lipids contained in the vinegar material into the solvent. Separate the degreasing solvent and extracted lipids from the leather material. It is not necessary to extract the entire amount of lipids contained in the vinegar material, but it is sufficient to extract the lipids to the extent that the leather material is not discolored by the lipids contained therein.

From this point of view, leather materials are sometimes subjected to an extraction process for lipids contained in the leather material at a normal moisture content without drying the leather material.

The leather material from which lipids have been extracted in this way is subjected to steam heat treatment. This steam heating is to supply steam directly to the leather material. External heating may also be provided from the outside.

This steam heat treatment is continued as long as the treated leather material does not reach a boiling state, and the steam heat treatment is performed while stirring the treated leather material in order to make the steam heat treatment effective.

The processing time of this steam heating is relatively determined by the characteristics of the leather material, processing temperature, room pressure, etc., but at least the treated leather material is sufficiently swollen and the collagen fibers are loosened. The subsequent drying and pulverization processes must be continued until the shaped leather powder has an apparent specific gravity of 0.30 to 0.50 g/cc.

As a result of this steam heat treatment, the lipids remaining in the vinegar material are further eluted, and the degreasing solvent, such as toluene and methyl chloride, used to elute the lipids is removed.

After removing the lipid content to the extent that it does not cause discoloration, remove the degreasing solvent such as toluene and methyl chloride, and forcefully dry it to reduce the moisture content of the leather material to 50%.
Dry until the content is within 3% by weight, ideally within 3% by weight.

Fine leather powder is produced by crushing this dried leather material with a crusher such as a Fine Victory Mill.

The apparent specific gravity of this fine powder leather powder is 0.30 to 0.
．． 50g/cc (Appearance in the present invention is loose specific gravity.Appearance is specific gravity.Leather powder placed in a 100cc container is ground and weighed on a 1-dish balance, and expressed as the weight of the leather powder, 1 round divided by 100. ), and 1F+ for each purpose.
Grind to a fine particle size.

Therefore, for boat fishing, we use the leather powder crushed with the Fine Victory Mill mentioned above, sorting it with a 40-mesh sieve, and further using an air classifier to reduce the average particle size to 24 mm.
．． 5 g m, most of which is used as powder etc. within 504 m.

In particular, the leather powder classified by an air classifier can be used by mixing it into paints, various coating liquids, etc. by making the leather powder finer than 404 m to 70% by weight or more of the total amount.

Furthermore, the leather powder crushed on an inclined surface is mixed with various paints, or mixed with solvents such as toluene and xylene used for liquefying various resins, and this is stirred in a wet ball mill, etc.
By pulverizing, it is possible to further reliably pulverize the powder.

Note that extraction of lipids using solvents such as diagonal toluene and methyl chloride is usually performed at room temperature, but if this is extracted under certain heating conditions, the processing time can be shortened. It was found that there was no inconvenience in the subsequent swelling treatment with water vapor.

In addition, when the leather powder was re-pulverized using various mills such as a wet type ball mill in "Kyo", the particle size of the leather powder was finer than 20 pm, and it was possible to obtain a leather powder that did not aggregate into cotton-like particles. .

The ultrafine leather powder formed on the slope does not entangle with phase 1, and since the lipid content is greatly reduced and degreasing solvents such as toluene and methyl chloride are removed, This 7H is applied directly to a resin material such as a polyurethane resin solution, and is used for molding resin moldings, resin films, resin sheets, resin paints, resin coating liquids, etc.

Alternatively, as another method, the leather powder produced in the above example is forcedly dried so that the moisture content in the leather powder is within 5% by weight, and then mixed with a solvent such as toluene or xylene.
iff Ia″ Disperse the powder in the solvent by stirring or stirring and pulverizing (using the various types of pulverizers described in the above examples), and each 1
] The desired synthetic resin is mixed with this and used in the same manner as above for resin molding, film, sheet molding, resin coating,
Used as resin coating liquid, etc.

Therefore, the solvent used at this stage is one suited to the characteristics of the respective synthetic resin to be used, and is distinguished from the solvent for extracting the lipids from the vinegar powder. In addition, the leather powder mixed into the solvent at this stage has the feature that it is uniformly dispersed in the solvent without a groove layer, and when a grinding process is added, the leather powder of the above example is further dispersed. This shows the characteristics of a fine powder.

The molded product, sheet, film, coating surface, etc. produced in the above example was subjected to sanding treatment, puffing treatment, graining treatment, molding treatment of molded leather, and other cosmetic treatments generally used for leather. give

Furthermore, by impregnating the molded article, sheet, film, coated surface, etc. with the scent of cowhide, pigskin, sheepskin, etc., characteristics even closer to those of natural leather can be brought about.

(Effects of the Invention) The method for forming fine leather powder according to the present invention is capable of producing extremely fine leather powder, which was previously considered difficult due to the unique structure of the slanted surface. I was able to obtain leather powder that I had never experienced before.

In addition, it was possible to efficiently remove lipid substances in leather powder, which had been considered a problem in the past.

Furthermore, since solvents such as toluene and methyl chloride in the leather powder are efficiently removed during the steam heating of the leather material, it is possible to obtain a leather powder that further enhances the soft properties peculiar to leather. Ta.

As a result, when resin molding is performed using the fine leather powder according to the present invention, the leather powder mixed into the molding resin is uniformly dispersed, eliminating the inconvenience of agglomeration like flocs, and preventing the leather powder from being mixed in. Leather powder has the flexibility characteristic of leather, and its particle size is finer, so there is no roughness on the surface of resin molded products such as molded products, sheets, films, etc.
This gives the molded product the smooth, moist texture unique to leather.

Furthermore, even when the 16 powder produced by the molding method of the present invention is used by mixing it into a paint liquid or coating liquid, it retains the softness characteristic of keratin and is smooth without any roughness. It was possible to create a coated surface that is moist and unique to leather.

In particular, the leather powder produced by the slope-up molding method is suitable for forming coating films, coating films, or films with jaw-shaped poles with a thickness of about 0.1 to 0.01 g++s, and these resins Leather powder contained in molded coatings, etc. has the feature that it is uniformly dispersed within these coatings, and provides the soft feel characteristic of leather without impairing the smoothness of the surface of the coating, etc.

Furthermore, the leather powder contained in resin-molded molded products such as molded products, films, sheets, and coating films has a significantly higher lipid content than conventional leather powder. As a result, discoloration of molded products caused by these contained lipids was effectively prevented.

Claims (1)

[Claims] The tanned leather material is cut or crushed, the lipids contained in the cut or crushed leather material are removed with a degreasing solvent such as toluene or methyl chloride, and the leather material is heated in supplied steam. 1. A method for forming leather powder, which comprises subjecting the treated leather material to a swelling treatment, and then pulverizing the treated leather material into a fine powder while being force-dried.