JPH01168977A - Synthetic leather - Google Patents

Abstract

PURPOSE:To obtain a synthetic leather having feeling of natural leather and rich in endurance, by blending a resin for synthetic leather with a leather powder especially treated and finely pulverized and used as filler and further glue or gelatin used as a binder and forming the blend into sheet. CONSTITUTION:10-30wt.% of a leather powder obtained by subjecting leather powder obtained from shaving process of tanned leather to cleaning treatment and then low-temperature drying at temperature range causing no loss of fiber ingredient in the leather and finely pulverized to 50-150 mesh pass and used as a filler is blended with a resin (e. g., vinyl chloride resin) for synthetic leather and uniformly dispersed and the resultant dispersion is formed into sheet or additive obtained by diluting glue or gelatin and used as a binder is blended with the above-mentioned dispersion at an amount of 0.5-1% in terms of dried weight of glue or gelatin and uniformly dispersed to provide the unfoamed synthetic leather sheet or further foamed to provide the formed synthetic leather sheet. The synthetic leather has feeling and physical properties close to that of natural leather and excellent moisture permeability.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to improvements in synthetic leather.

(Prior art and its problems) Synthetic leather sheets are widely used as automobile seat materials, and in recent years, for example, synthetic resin liquid mixed with leather powder has been applied to fabric to form a leather-like coating, and leather-like properties have been developed. A sheet has been proposed that has
No. 384).

However, since such leather powder is produced in large quantities as a leather by-product during the shaving process, there is a problem in that striped patterns appear on the sheet surface as a result of changes over time, significantly reducing the commercial value.

Therefore, the present inventor has developed a method of cleaning leather powder obtained in the shaving process of tanned leather, drying it at a low temperature within a temperature range where the fiber components are not lost, and finely pulverizing the dried leather powder into 50 to 150 grains. , a leather powder that can eliminate the disadvantage of leather powder produced as a by-product of the shading process, which causes striped patterns to appear on the sheet surface due to changes over time, without destroying the fibers that create the texture of natural leather. We have now provided the following.

(Object of the Invention) The first object of the present invention is to use such treated leather powder to provide synthetic leather of excellent quality.

By the way, by uniformly dispersing leather powder throughout the resin layer, it is possible to impart the physical properties of natural leather to the resin layer, but when the amount of leather powder added is large, it becomes difficult to distribute the leather powder uniformly throughout the resin layer. If it is not dispersed, the tensile strength of the resin layer will decrease, resulting in a lack of durability.

Therefore, the second object of the present invention is to provide synthetic leather that can uniformly disperse leather powder in a synthetic resin layer and maximize the effect of adding leather powder without reducing the tensile strength of the synthetic leather. There is a particular thing.

(Means for Achieving the Object) The first aspect of the present invention is that after washing the leather powder obtained in the shaving process of the tanned leather as a filler for the synthetic leather resin, the fiber components are removed. Synthetic leather sheet made by blending 10 to 30% by weight of leather powder which is dried at a low temperature within a temperature range that does not cause loss, finely pulverized to 50 to 150 mesh, uniformly dispersed and formed into a sheet.

In the present invention, leather powder used as a filler is treated as follows.

The lower limit of the washing temperature is preferably 30° C., at which the removal effect of various chemical components impregnated in leather powder is dramatically improved. If it is less than that, we cannot expect much removal effect, and if it is more than that, there will not be much change, so taking thermal efficiency into consideration,
It is best to wash at 50°C. In order to increase the cleaning effect, a small amount of a penetrant such as LTS-1000 and Riviere M (trade name: manufactured by Sanwa Kagaku Kogyo Co., Ltd., Osaka, Japan) may be added to the cleaning water.

For drying after washing, it is necessary to heat dry at 100° C. or lower under atmospheric pressure or to dry under reduced pressure. 100℃ under atmospheric pressure
If the leather powder is dried above, the fiber components in the leather powder will be thermally decomposed and lost, and the desired effect will not be achieved. For pulverization, it is best to dry to a moisture content of 5% or less.

After the leather powder thus obtained is crushed, it is screened and finely crushed to a particle size in the range of 50 to 150 mesh passes is recovered.

When the mesh pass is less than 150, the physical properties of the fiber components of the leather powder cannot be effectively utilized, and the texture of natural leather cannot be created. On the other hand, when the number of mesh passes exceeds 50, the surface becomes rough and the surface condition deteriorates. Therefore, 50~
A range of 150 mesh passes is preferred. .

As the resin for synthetic leather, thermoplastic resins that are generally used for synthetic leather, such as vinyl chloride resin and urethane resin, are used, and 10 to 30% by weight of the above-treated leather powder is used.
It is preferable that the filler be filled in a range of 100%, uniformly dispersed, and processed into a sheet by a coating method typified by calendering.

This is because if the blending amount is less than 10% by weight, the effect of adding leather powder will not be exhibited, while if it exceeds 30% by weight, the durability as a sheet material such as tensile strength will be lacking. However, when foaming the synthetic resin layer, considering the synergistic effect with the bubbles,
The effect of adding leather powder appears from the blending amount of 5% by weight, but 1
If it exceeds 5% by weight, the durability as a sheet material such as tensile strength decreases, so it is preferably in the range of 5 to 15% by weight. Therefore, the present invention provides the following advantages: [For synthetic leather resin, leather powder obtained in the shaving process of tanned leather as a filler for filling is washed and then dried at a low temperature within a temperature range where the fiber components are not lost. Another object of the present invention is to provide a "synthetic leather sheet" which is formed by foam-molding 5 to 15% by weight of leather powder finely ground to 150 mesh.

According to the above structure of the invention, foamed and non-foamed synthetic leather sheets have the texture of natural leather, such as moisture permeability, which is not found in conventional synthetic leather, without impairing the durability required for synthetic leather such as tensile strength. can be granted. In particular, vinyl chloride sheets have an extremely low moisture permeability compared to urethane sheets, so they have the disadvantage of being inferior in texture, and although they have the advantage of being cheap and durable, they are currently treated as cheap products. However, even if vinyl chloride resin is used as a main ingredient, improved synthetic leather with excellent moisture permeability can be provided.

On the other hand, in the above structure, the fiber component of leather powder is thought to function as an additive in the form of a filler for the synthetic resin, but leather powder is produced as a by-product of natural leather as a binder between the leather powder fiber component and the synthetic resin component. By using glue or gelatin, it is possible to give synthetic leather an even more natural leather feel. Therefore, the second configuration of the present invention is to use "leather powder obtained in the shaving process of the leather that has been used as a filler for synthetic leather resin after washing treatment.
Dry at a low temperature within the temperature range that does not destroy the fiber components, and
Leather powder pulverized to 50 mesh ~30% by weight
A non-foamed synthetic leather sheet and [for synthetic leather resin, after washing leather powder obtained in the shaving process of tanned leather as a filler, the resin is heated at a low temperature in a temperature range that does not cause loss of fiber components. Contains 5-15% by weight of leather powder that has been dried and finely ground to 50-150 mesh.
When forming a foamed synthetic leather sheet, [additives made by diluting glue or gelatin as a binder are used in an amount of 0.5 to 10% by weight of glue or gelatin dry weight]
The object of the present invention is to provide a "synthetic leather sheet" which is made by blending, uniformly dispersing, and forming into a sheet shape.

The glue or gelatin blended as a binder must be uniformly dispersed in the synthetic resin component. However, even if glue or gelatin powder is directly mixed with synthetic leather resin, it is difficult to disperse it uniformly. Therefore, in the present invention, when using vinyl chloride resin as the synthetic leather resin, glue or gelatin is When using a urethane resin, it can be mixed with a polyol component or a glycol component, which is a chain extender, and diluted. Good.

The amount of the resin to be blended is preferably 0.5 to 10% by weight based on the dry weight of glue or gelatin.

This is because if the amount is less than 0.5% by weight, the desired effect of addition will not be achieved, while if it is more than 10% by weight, it will impede the durability of the synthetic leather.

According to the second configuration of the present invention, the glue or gelatin component having resinous properties acts as a binder between the leather powder and the synthetic resin, thereby making it possible to bring out the feel of natural leather even more. Incidentally, the moisture permeability is more than twice as high as when only leather powder is added and mixed. In addition, when a synthetic leather sheet containing glue or gelatin components is treated with hot water, a portion of the glue or gelatin in the synthetic leather sheet is washed away, forming pores similar to the pores of natural leather. It has been found that the properties are dramatically improved and physical properties comparable to those of natural leather appear.

Currently, as a method of imparting breathability to synthetic leather sheets, ■
Mechanical/electrical perforation method; ■Method of stencil printing plastisol on the base fabric and utilizing the exposed texture of the base fabric; ■Method of mixing water-soluble DMF, rolling coating, and washing with water. A method of eluting DMF has been proposed, but
The hot water-treated sheet according to the present invention is different in that it is thought that as a result of communication between the outside and the glue or gelatin and leather powder components inside the resin through pores, it forms a physical structure similar to that of natural leather. .

The first and second configurations of the present invention described above can be utilized for a synthetic leather sheet made of soft vinyl chloride, urethane resin, etc., which has a top layer on the surface of a foam layer and a membrane end portion. That is, the third configuration of the present invention is a synthetic leather sheet having a top layer on the surface of the foam layer and a top layer at the edge of the foam layer. After washing the leather powder obtained in the process, it is dried at a low temperature within a temperature range that does not lose the fiber components, and 5 to 15% by weight of the leather powder is finely pulverized to 50 to 150 mesh, and foam molding is carried out. Alternatively, leather powder obtained in the shaving process of tanned leather as a filler for synthetic leather resin is washed, dried at a low temperature within a temperature range that does not destroy the fiber components, and finely pulverized to 50 to 150 mesh. An additive made by diluting 5 to 15% by weight of leather powder and glue or gelatin as a binder to dry glue or gelatinffi! in,
0.5 to 10% by weight is blended and foam molded,
For the top layer, leather powder obtained in the shaving process of tanned leather is used as a filler for synthetic leather resin, and after washing, it is dried at a low temperature within a temperature range that does not lose the fiber components, and then finely divided into 50 to 150 mesh. Crushed leather powder 10~
After washing the leather powder obtained in the shaving process of tanned leather as a filler for filling resin for synthetic leather or by mixing 30% by weight to form a film, it is heated at a low temperature in a temperature range that does not cause loss of fiber components. 10 to 30% by weight of leather powder obtained by drying and finely pulverizing to 50 to 150 meshes, and an additive made by diluting glue or gelatin as a binder to 0.5 to 10% by weight as a glue or gelatin component. The purpose of the present invention is to provide a synthetic leather sheet formed by forming a film using

Generally, when it is necessary to apply a leather surface treatment agent as a surface layer, a surface treatment agent containing 0.5 to 10% by dry weight of glue or gelatin is applied. It is preferable to do so because it does not impede blending with the underlying layer.

Hereinafter, the present invention will be explained in detail based on examples. (Leather powder production example) After the toughening process, the leather powder obtained in the shaving process is washed with hot water, and after draining, a penetrant is added and stirred for 2 hours under hot water. After draining, rinse with water for 1 hour, drain again, add penetrant, and stir under warm water for 1 hour. After that, draining water and washing with hot water are repeated three times.The washed leather powder is slowly dried at a low temperature under atmospheric pressure at a furnace temperature of 60 to 80°C until the moisture content is 5% or less. (manufactured by Itoman Engineering) and then screened to collect leather powder of 50 to 150 mesh passes.

(Example 1) 100 parts by weight of a soft vinyl chloride compound for synthetic leather was heated and melted, and the treated leather powder according to the present invention (100 parts by weight) was added to it.
0 mesh pass) was mixed, uniformly dispersed, and formed into a sheet using a calender roll.

(Example 2) 100 parts by weight of a soft vinyl chloride compound for foamed synthetic leather was heated and melted, 5 parts by weight of the treated leather powder according to the present invention (100 mesh pass) was mixed therein, and the mixture was uniformly dispersed and calendered. After forming into a sheet with a roll, it is foamed through a heating process to produce a foamed sheet.

(Comparative Test Example 1) On the other hand, in place of the leather powder according to the present invention, untreated leather powder (100
A sheet was formed by mixing the same amount of Mesh Pass) and uniformly dispersing it, and its change over time was observed.

As a result, the sheet using the leather powder according to the present invention has the same natural leather texture such as moisture permeability as the sheet using the untreated leather powder, but no change occurs on the surface. ,
A striped pattern appeared on the surface of the sheet made of untreated leather powder, which significantly impaired the appearance of the product.

(Example 3) Glue or gelatin was pre-mixed with a plasticizer and a dispersion stabilizer to 100 parts by weight of a soft vinyl chloride compound for synthetic leather, diluted and dispersed, and the dry weight was 5M% based on the resin content. parts by weight are added and stirred and mixed under heating,
155 parts by weight of the treated leather powder according to the present invention (100 mesh pass) is mixed with this, uniformly dispersed, and formed into a sheet using a calender roll.

(Example 4) Soft vinyl chloride compound tooi for foamed synthetic leather
To part ii, glue or gelatin is mixed in advance with a plasticizer and a dispersion stabilizer, diluted and dispersed, and a weight part of 5% by weight of dry weight based on the resin content is added and mixed with stirring under heating. , 5 parts by weight of the treated leather powder according to the present invention (100 mesh pass) is mixed with this, uniformly dispersed and formed into a sheet using a calendar roll, and then foamed through a heating process to produce a foamed sheet. .

(Examples 5 and 6) The vinyl chloride sheets produced in Examples 3 and 4 were
It was immersed in hot water at around 0°C, treated with hot water, and dried.

On the other hand, in place of the leather powder according to the present invention, untreated leather powder (100
Examples 3 and 4 except that the same amount of mesh pass) was mixed.
A sheet was formed in the same manner as above and subjected to hot water treatment. As a result, the sheet using the leather powder according to the present invention has the same natural leather texture such as moisture permeability as the sheet using the untreated leather powder, but no change occurs on the surface. A striped pattern appeared on the surface of the sheet made of untreated leather powder, which significantly impaired the appearance of the product.

(Moisture permeability comparison test example) Japanese Industrial Standards “Leather moisture permeability test method J (JISK654
9), the moisture permeability of the synthetic leather sheets manufactured in Examples 1 to 6 was tested and compared with untreated natural leather. The results are shown in Table 1 below.

In addition, in this standard, moisture permeability refers to the amount of water vapor that passes through a unit area of membrane material in a certain period of time, and is defined as
, with the leather as the interface and the air on one side at a relative humidity of 80
±5%, and when the air on the other side is kept dry, convert the mass (mg) of water vapor that passes through this interface per hour to its base 1c+4, and use that value as the moisture permeability. There is.

Table 1 Test items Average value (IIIg/-・hr) Example 1
011 2 0.2 3 0.2 4 0.25 Hot water treatment example 5 0.5 6 0.6 Natural leather (untreated) 1. 0 PVC sheet O (Example 7) As shown in Example 1, 100 parts by weight of a soft vinyl chloride compound for synthetic leather was heated and melted, and 155 parts by weight of the treated leather powder (100 mesh passes) according to the present invention was added to this. As shown in Example 2, the top layer is partially mixed, uniformly dispersed, and formed into a film using a calendar roll;
100 parts by weight of a soft vinyl chloride compound or urethane resin compound for foamed synthetic leather is heated and melted, 5 parts by weight of the treated leather powder according to the present invention (100 mesh pass) is mixed therein, and the mixture is uniformly dispersed and rolled into a calendar roll. After forming the material into a sheet, the material was bonded to a foamed sheet formed by foaming through a heating process to produce synthetic leather.

(Example 8) As shown in Example 3, to 100 parts by weight of a soft vinyl chloride compound for synthetic leather, glue or gelatin was added in an amount of 5% by weight on a dry weight basis based on the resin content, and the mixture was heated. The treated leather powder according to the present invention (1
00 mesh pass), uniformly dispersed and formed into a film using a calendar roll, and as shown in Example 4, 100 parts by weight of a soft vinyl chloride compound for foamed synthetic leather and glue. Alternatively, gelatin is added in an amount of 5% by dry weight based on the resin content, stirred and mixed under heating, and treated leather powder according to the present invention (1
A synthetic leather sheet was produced by mixing 5 parts by weight of 00 mesh pass), uniformly dispersing the mixture, and forming it into a sheet using a calendar roll, foaming it through a heating process, and adhering it to a foamed sheet.

(Effects of the Invention) As is clear from the above description, according to the first configuration of the present invention, leather powder obtained in the shaving process of tanned leather is added to the synthetic leather resin as a filler. After washing, dry at a low temperature within the temperature range that does not destroy the fiber components.
Synthetic leather sheets are manufactured by blending leather powder that has been finely ground to 50 to 150 mesh, so the properties of the leather powder are effectively utilized without impairing the durability required for synthetic leather, such as tensile strength. Improves moisture permeability, which was a drawback of synthetic leather,
It is possible to impart the feel of natural leather, and at the same time, the various components impregnated in the toughening process do not leach onto the surface of the synthetic leather and impair its quality.

On the other hand, according to the second configuration of the present invention, the effect of adding leather powder is enhanced by using in combination the leather powder blended as a filler and the additive made by diluting the glue or gelatin blended as a binder. As a result, the texture of the natural leather including moisture permeability can be improved more than when using leather powder alone. Moreover, in such a structure, the glue or gelatin used as a binder is diluted and dispersed, so when hot water treatment is applied, a part of it is washed away, forming many pores similar to natural leather pores, and the resin Since the leather-like structure formed by the internal fiber component made of leather powder and the remaining glue or gelatin component communicates with the outside, physical properties similar to natural leather can be imparted.

Furthermore, in producing synthetic leather by film-refining the top layer on the surface of the foam layer, we not only give the top layer a natural leather texture, but also the base fabric layer. As a result, not only the surface physical properties but also the overall tissue physical properties can be configured to resemble natural leather, resulting in, for example, a directionality with respect to tension that is not seen in conventional synthetic leather.

In particular, vinyl chloride sheets have an extremely low moisture permeability compared to urethane sheets, so they have the disadvantage of inferior texture.
Although it has the advantage of being cheap and durable, it is currently treated as a cheap product, but now we can provide an improved synthetic leather that is made mainly of vinyl chloride resin and has excellent moisture permeability. Moreover, it has the advantage of having additional effects such as heat retention, water retention, electrical conductivity, and aging resistance (preventing plasticizer from escaping).

The sheet according to the present invention is a synthetic leather that has been separately filed by the applicant, i.e., an additive made by diluting and dispersing glue or gelatin in a resin for synthetic leather as a glue or gelatin component of 0.5 to 10% by dry weight. Needless to say, it is also possible to use the synthetic leather sheet in an appropriate combination with a synthetic leather sheet having a foamed or non-foamed layer formed by blending % by weight and uniformly dispersing a glue or gelatin component and laminating it.

Claims (8)

[Claims] (1) After washing the leather powder obtained in the shaving process of tanned leather as a filler for synthetic leather resin, drying it at a low temperature within a temperature range that does not destroy the fiber components,
Leather powder 10-30 finely ground to 50-150 mesh
A non-foamed synthetic leather sheet made by blending % by weight, uniformly dispersing it, and forming it into a sheet. (2) The synthetic leather sheet according to item (1) above, wherein an additive made by diluting glue or gelatin as a binder is mixed and uniformly dispersed in an amount of 0.5 to 10% by dry weight of glue or gelatin. . (3) Glue or gelatin as the surface layer, dry weight: 0.5
The synthetic leather sheet described in item (1) or item (2) above, wherein the synthetic leather sheet is coated with a surface treatment agent containing up to 10% by weight. (4) After washing the leather powder obtained in the shaving process of the tanned leather as a filler for the synthetic leather resin, drying it at a low temperature within a temperature range where the fiber components are not lost;
A foamed synthetic leather sheet formed by foam molding a mixture of 5 to 15% by weight of finely ground leather powder of 50 to 150 mesh. (5) The foamed synthetic leather sheet according to item (4) above, which contains an additive obtained by diluting glue or gelatin as a binder in an amount of 0.5 to 10% by dry weight of glue or gelatin. (6) Glue or gelatin as the surface layer, dry weight: 0.5
The synthetic leather sheet as described in item (4) or item (5) above, which is coated with a surface treatment agent containing up to 10% by weight. (7) In a synthetic leather sheet formed by film-refining the top layer on the surface of the foam layer, the foam layer is treated with leather powder obtained in the shaving process of the tanned leather as a filler for the synthetic leather resin. Leather powder 5 to 15 is then dried at a low temperature in a temperature range where the fiber components are not lost and finely ground to 50 to 150 mesh.
% by weight or further diluted glue or gelatin as a binder by blending 0.5 to 10% by weight of glue or gelatin dry weight and foam molding. After washing the leather powder obtained in the shaving process of tanned leather as a filler for synthetic leather resin, it is dried at a low temperature in a temperature range that does not lose the fiber components, and is finely ground to a size of 50 to 150 mesh. A film is formed by mixing 10 to 30% by weight of leather powder, or further diluting glue or gelatin as a binder and adding an additive of 0.5 to 10% by dry weight of glue or gelatin. Synthetic leather seats. (8) Glue or gelatin as the surface layer, dry weight: 0.5
The synthetic leather sheet according to item (7) above, which is coated with a surface treatment agent containing up to 10% by weight.