JPS63152481A - Leather-like molded article - Google Patents

Abstract

PURPOSE:To obtain a leather-like molded article having excellent flexibility, impact effects and water vapor absorption, by blending a thermoplastic resin containing an elastic material of synthetic rubber with leather powder and granular gelatin, molding under heating and making the gelatin in the molded article have a fixed water content. CONSTITUTION:A thermoplastic resin (e.g. vinyl chloride resin, etc.) containing an elastic material of synthetic rubber such as butadiene synthetic rubber is blended with 5-30wt% granular gelatin to give a resin compound. 30-90wt% of the resin compound is mixed with 10-70wt% leather powder selected by 30 meshes sieve and molded into a sheetlike or filmlike shape by calendering rolls. The gelatin granules in the molded article have usually about 16% water content, the molded article makes the same environment as that existing as a biopolymer in organism, has high impact absorbing effects and shows excellent freeze resistance by admixture of the leather powder.

Description

Detailed Description of the Invention (Industrial Field of Application) This invention relates to a method for producing leather whose main components are gelatin and collagen protein as biopolymers containing various amino acids such as glycine, proline, and hydroxyproline, as well as ash and moisture. It is intended to incorporate powder into a synthetic resin molded product to make the synthetic resin molded product have properties similar to natural leather. The properties of the molded product are changed by uniformly scattering these gelatin particles and creating a swollen state similar to the situation in which these scattered gelatin particles are actually positioned as biopolymers.

(Prior art) Leather has been used as a material closely related to daily life since ancient times, and due to the properties of the unique collagen fiber bundles of leather fabric, it has moisture absorption, heat resistance, and cold resistance properties, and can be used as a strong fabric material. Ta.

However, such natural leather materials have a limited supply, are at risk of becoming brittle due to swelling, rotting, magnetizing, and discoloring, and are always subject to constraints in terms of shape.

Therefore, in recent years, improvements have been made to synthetic leather or artificial leather that has the characteristics inherent to leather, such as polyamide, polyurethane, or polyamino acid synthetic leather, or three-dimensional fiber entanglement of special lotus root type hollow fibers or fine fiber bundle type fibers. Artificial leather and the like are now being supplied, which are made of a porous structure of a binder made mainly of polyurethane elastomer.

However, all of these methods attempt to create water absorption, permeability, or elasticity through reticulation or porosity using synthetic resin materials that do not swell, and are different from natural leather based on biopolymers. It was considered difficult to develop similar properties.

(Problem to be solved by the invention) As a method of using leather materials as they are, these leather materials are broken and beaten into short fibers, and the short fibers of leather material are pressed into a felt shape. Felt materials, filter vortex materials, and vibrating fabric materials for speakers have been developed for some time. However, the development of turning leather material into powder by crushing or cutting it and making leather fabric from this powdered leather material was first carried out industrially by the applicant Mizu, and patent application No. 81-102813, etc. Many inventions have been disclosed.

By the way, when such leather material is pulverized and mixed with resin and molded, it has been found that the finer the leather powder is, the better the properties of the molded leather-like fabric are, and the easier it is to blend with the resin. did.

However, when pulverizing leather material, it is technically difficult to make powder that is not fibrous and has a particle size because the leather material is collagenous. When the particle size is above or below the particle size, there is a problem in that the leather powder becomes entangled with each other in a cotton-like manner.

In particular, the leather material is crushed by a crusher or ultrafine crusher, etc.
When made into a uniform fine powder of about 0 mesh, the fine powder becomes intertwined with each other and takes on a cotton-like appearance, and does not mix properly with the synthetic resin material. It exists as a tangled mass, and this was considered to be the cause of pulsation in the molded resin during extrusion molding and the like.

In addition, if the leather material becomes a certain lump like this, a molded product will be obtained in which the resin material and the leather material are separated, and of course the strength of the molded product will be extremely poor. However, there was an inconvenience in that the molded product did not have any of the characteristics of the leather material to which it was mixed.

Based on the above points, the applicant has attempted to improve the mixing of gelatin and leather powder, which are biopolymers similar to those used in leather powder, and has achieved better results than expected as a substitute for leather powder. was able to obtain.

(Object and structure of the present invention) The leather-like molded article according to the present invention relates to an improvement on the prior art described above, and focuses on gelatin, which is easier to mold than leather powder and can be mass-produced at a lower cost. However, by incorporating this gelatin, the intention was to reduce the amount of leather powder used, and to derive functional characteristics that were at least the same as or better than those of molded products using leather powder.

The leather-like molded product according to the present invention, as a means of achieving the above-mentioned purpose, first pulverizes the gelatin to be mixed in so that it is evenly mixed with the synthetic resin material, and then transforms it into a synthetic rubber elastic material. heat-molded with thermoplastic resin containing leather powder and leather powder. As a result, the mixed gelatin became extremely fine particles and was scattered in the molded article together with the leather powder, so that the leather powder and a portion of the gelatin particles were in continuous contact with each other.

Molded articles were obtained by making these gelatin particles contain water, usually about 16%, to create an environment similar to that existing in living organisms as biopolymers.

(Functions and Effects) It has been confirmed that the leather-like molded article according to the present invention has the following functions and effects because it has the above structure.

(1) Gelatin has the property of becoming brittle when it is released from its swollen state and dried, so it can be easily made into fine particles. I was able to create it.

(2) When mixed into thermoplastic resins containing synthetic rubber elastic materials, gelatin has a unique slipperiness similar to talc, so it has the ability to mix evenly into these resin materials. Moreover, since it also has the function of inducing leather powder into the resin material, uneven distribution of gelatin particles and leather powder that would otherwise be present in the molded product can be avoided.

(3) The mixed gelatin easily becomes a sol during the heat treatment during molding, which increases the fluidity of the entire molded resin, making resin molding easier, and also changing the composition of the molded product into a sol. As a result, it has the advantage of preventing molding distortion of the molded product.

(4) The gelatin particles that are evenly scattered throughout the molded product exhibit high viscoelasticity as they gel, creating a net-like viscoelastic structure in the molded product and a net-like synthetic resin that incorporates this structure. By creating an aggregate structure, high values were shown for bending fracture strength, shock absorption properties, etc.

(5) Since the gelatin particles in the molded product are swollen and viscous like ordinary biopolymers, and contain leather powder, the molded product always has a constant water content, especially close to that of human skin. Its heat conduction, heat retention, and contact resistance values are said to be close to those of the skin, making it particularly suitable for use in areas that come in contact with humans.

(6) When the gelatin particles and leather powder in these molded products are in contact with each other, these gelatin particles themselves are sequentially swollen or dried, making it difficult to adjust humidity through the molded product. was allowed to do so.

(7) When gelatin particles and leather powder in a molded product are exposed on the surface of the molded product, the gelatin particles and leather powder on the surface directly absorb moisture and swell, and the absorbed moisture is sequentially transferred to the molded product. It has the function of feeding deep into the skin, prevents a sticky feeling upon contact, and has the same resistance as human skin.

(8) Particulate gelatin is evenly dispersed in the molded product, and these particles contain a predetermined amount of water and are in a swollen state, which prevents static electricity inherent in synthetic resins and reduces static electricity. It is said to be effective for use in areas where static electricity is likely to be generated, or for use in various electrical equipment where generation of static electricity is averse.

(Example) Hereinafter, a typical example of the leather-like molded article according to the present invention will be described.

First, the synthetic resin 1 used as the base material is butadiene-based synthetic rubber,
Synthetic rubber elastic materials such as olefin synthetic rubber, polysulfide rubber, fluorine comb, polyurethane rubber, colorosulfonated polyethylene, silicon rubber, and chloride rubber, and heat-resistant materials such as vinyl chloride, vinyl acetate, ABS, polycarbonate, polyethylene, and polystyrene. It is used selectively from plastic resins, etc.

The gelatin 2 that is then mixed in typically has an average molecular weight of 200.
It is a derived protein with a molecular weight of 0.00 to 150,000, and is gelled by drying to a water content of nearly 16%, and crushed in this hardened state to form colored or non-colored fine particles. As much as possible, the particle size of gelatin 2 was adjusted to about IILm so that the following kneading, molding, and various functions in the molded product could be effectively achieved.

The leather powder 3 is a fine powder obtained by pulverizing green leather, shaving waste, etc., and the optimum particle size is usually selected through a 30-mesh sieve as shown below.

150 mesh sieve passing rate 54.7%100
~150 me-7' / 18.4$6
0~100 mesh l/15.5z 80 mesh//' 11.5
% cal resin 1, gelatin 2 and leather powder 3 are approximately 5~
Resin compound 30-90 containing 30% gelatin 2
A typical example is a case where 10 to 70% of leather powder is mixed in, and a plasticizer used in resin molding is usually added to the resin l.
A molded article was obtained by calender roll, extrusion, injection or other method on a compound to which stabilizers, fillers, lubricants, pigments or dyes, blowing agents and mold release agents were added.

The film and sheet-like molded products were mainly soft or semi-hard, and the injection molded products were mainly hard or semi-hard.

Furthermore, by laminating cloth or paper as a reinforcing material to film and sheet-like molded products, their tear strength can be increased or distortion can be prevented.

In addition, the surface of the molded product is subjected to leather graining, sanded to give it a suede look, and various surface decorations such as enamel finishing and other finishing touches are applied.

The gelatin 2 in the molded article constructed as described above became hydrated and swollen before and after its air-dried moisture content, giving the molded article a unique function.

(1) It exhibits remarkable viscoelasticity for molded products that do not contain gelatin, provides a soft feel, and has a large impact absorption effect.

(2) It has good hygroscopicity and prevents dust from adhering to it due to static electricity.

(3) Distortion in the resin was absorbed by the presence of gelatin particles, preventing distortion over time after molding, effectively preventing deterioration, and providing good oil resistance.

(4) Since gelatin particles and leather powder serve as carriers, coloring and surface coating treatments are easy, and the gloss and color tone are good.

(5) Since the gelatin particles and leather powder act as carriers, the adhesive properties are good and the adhesive processing is easy.

(6) Due to the high frictional resistance of gelatin particles and leather powder, slipping does not occur even on wet or frozen surfaces.

(7) Since the gelatin particles were incorporated into the molded product as a unique structure, a significant vibration damping effect was produced.

(8) The inclusion of gelatin particles and leather powder provides good cold resistance, and the molded product will not tear or crack even in cold weather.

[Brief explanation of the drawing]

The attached drawing is an enlarged sectional view of the main part of the molded product according to the present invention. 1...Resin, 2...Gelatin, 3...Leather powder.

Claims (1)

[Claims] 1. A leather-like molded article, characterized in that the gelatin in the molded article is formed by heating and molding a thermoplastic resin containing a synthetic rubber elastic material mixed with leather powder and granular gelatin, and the gelatin contains water.