JPS5830920B2 - Method for producing leather-like substance - Google Patents

Description

[Detailed description of the invention] The present invention relates to a method for producing a leather-like material.

Specifically, natural leather scraps are crushed and fibrous leather powder or a mixture of natural leather powder and heat-fusible adhesive powder is applied onto the base material, and then passed through a heated pressure roll. The present invention relates to a method for producing a leather-like material, which comprises integrating the leather powder coating layer to form a leather powder coating layer, then applying a thermoplastic resin liquid onto the leather powder coating layer, drying the coating layer, and then pressurizing the coating layer.

It is conventionally known technology to produce leather-like materials by depositing leather powder onto a substrate.

For example, a method in which an adhesive mixed with leather powder is applied onto a base material, and while the surface is sticky, the leather powder is adhered by electrodeposition, followed by light pressure, pre-drying, and curing in sequence. 31.219) or a method of electrodepositing dyed leather powder onto a substrate via an adhesive (Japanese Patent Application Laid-open No. 49-25-102).

However, these methods merely adhere the leather powder onto the base material via an adhesive, and have the drawback that the leather powder easily falls off simply by rubbing the surface.

In addition, tear strength, water resistance, dry cleaning resistance,
In terms of texture, it is currently inferior to leather-like materials known as conventional leather, polyvinyl chloride leather, and synthetic suede.

The present invention relates to the improvement of the leather-like material produced by the above-mentioned conventional method. This is a method for producing a leather-like material by applying resin and applying pressure.

The present invention is characterized in that a mixture of natural leather powder and heat-fusible adhesive powder is heated and pressed to integrate, and then a thermoplastic resin is applied and pressed. Because the gaps are filled with heat-adhesive adhesive and thermoplastic resin, the leather powder does not fall off even when scratched or rubbed, and it also has other physical properties such as tear strength, water resistance, and dry cleaning resistance. , they succeeded in penetrating a leather-like substance that has the texture and feel of leather.

In detail, the present invention utilizes leather scraps generated in the leather industry, and first, the leather scraps are crushed into fibers to produce leather powder or the leather powder and a heat-fusible adhesive powder. The mixture is applied onto a substrate and then passed through heated pressure rolls to form an integrated leather powder coating layer.

The leather powder to be used can be any natural leather such as cowhide, pigskin, goatskin, or sheepskin, but it is particularly desirable to use tanned leather, and the leather waste can be crushed using a well-known means such as a grinder. It is made into a fibrous powder.

Moreover, this may be dyed in advance.

The heat-fusible adhesive powder used with this leather powder includes powdered resins such as polyvinyl ether, polyamide, polyester, polyurethane, ethylene/acrylic copolymer, cellulose, and EVA. It is a thing.

The particle size of these leather powders and polymer powders is usually 30 meshes or less, preferably 30 to 150 meshes, and most preferably 50 to 100 meshes.

The blending ratio of leather powder and heat-fusible adhesive powder is 1:1 ~
It is 2.

This is because if the amount of the heat-fusible adhesive powder is too small, a uniform leather powder coating layer cannot be formed, whereas if the amount is more than twice that amount, the feel and feel of natural leather cannot be achieved.

The method of applying a mixture of leather powder and heat-fusible adhesive powder to a base material is usually by using a scattering method in which the powder is sprinkled uniformly on the base material and then passed through a heated pressure roll. do.

When passing through this heated pressure roll, the temperature is adjusted to the melting temperature of the heat-fusible adhesive powder used, and the pressure is 5 to 5.
20 kg/cm2.

The base material used in the present invention includes woven fabric, nonwoven fabric, knitted fabric, paper, synthetic leather, artificial leather, etc., but is not particularly limited to these.

In the present invention, a thermoplastic resin liquid is further applied onto the leather powder coating prepared by the above method.

However, not all types of thermoplastic resin liquids can be applied.

The purpose of the thermoplastic resin liquid used in the present invention can be achieved as long as it has a viscosity of 5,000 to 100,000 centipoise, preferably 10,000 to so, ooo centipoise during coating. It cannot be done.

In other words, if an ungrooved resin liquid with a viscosity of 5,000 centipoise is used, the resin liquid will immediately impregnate from the leather-like powder layer to the base material layer, and the leather-like material obtained by pressurizing this will have no moisture permeability. At the same time, it lacks flexibility and has a rough texture and feel, resulting in a product that is completely different from natural leather.

On the other hand, when the viscosity exceeds 100,000 centipoise,
The resin liquid does not easily enter the gaps between the leather powder and simply forms an additional layer on top of the leather powder coating layer.For this reason, the surface of the product obtained by pressurizing this resin has a resin layer, unlike conventional methods. This is undesirable because it will be no different from the synthetic leather.

In the present invention, the viscosity during coating is 5,000 to 100,000.
It is essential to use a thermoplastic resin liquid with a centipoise.

As a result, the resin liquid is filled into the gaps between the leather powder, and when this is pressurized, the leather powder integrated with the heat-adhesive adhesive is further sandwiched between the thermoplastic resin, and the leather powder is applied to the surface. This is because it can make it appear.

The thermoplastic resin liquid used in the present invention includes urethane resins, amino acid resins, acrylic resins, vinyl chloride resins, polyester resins, polyamide resins, cellulose resins, ethylene-vinyl acetate copolymer resins, etc. A solution or an emulsion of these thermoplastic resins can be used.

These resin liquids are applied to the leather powder coating using a roll coater.
Apply using a method such as a knife coater.

The coating amount varies depending on the type of resin, the thickness of the leather powder coating layer, the desired texture, etc., but it should be determined so that the moisture permeability of the product is at least 80,097 m2/24 hours.

This is one condition that the leather-like material of the present invention can be used for the same purposes as natural leather.

For this purpose, the resin solid content (hereinafter the same) is usually 5.
~10oz/rrL2 is applied.

Furthermore, the present invention is characterized in that the thermoplastic resin liquid is applied and then subjected to pressure treatment.

This is necessary in order to more strongly entangle the resin that has penetrated into the gaps of the leather powder described above with the leather powder.

However, there is no particular regulation regarding pressure.

Note that the leather-like material obtained in the present invention can be further subjected to operations such as puffing and raising the surface to make it fluffy.

Next, the method of the present invention will be explained in more detail with reference to Examples.

Example 1 Approximately 100 meshes of cowhide leather powder and polyamide heat-fusible adhesive powder (trade name: Buratamide H1059-801, approximately 200 meshes, manufactured by Toagosei Kagaku Kogyo Co., Ltd.) were mixed in a 1:1 weight ratio. Then, the mixed powder is applied uniformly over the entire surface of the base fabric by a scattering method on a plain-woven raised fabric, and then it is heated to 120°C and passed between rolls whose pressure is adjusted to 10 kg A2 to integrate it and form leather. A similar substance was obtained.

Next, an amino acid resin solution (product name: PLO-301 modified poly-γ-methylglutamate manufactured by Kyowa Hakko Kogyo Co., Ltd.) with a viscosity of go and ooo centipoise was applied to this surface.
After drying at 100°C for 2 minutes, the film was passed through a pressure roll whose temperature was adjusted to 120°C at a pressure of 20 kg/crrE, and a leather-like substance closely resembling natural leather was formed.

The moisture permeability of this material was 1500 g/m2 for 24 hours.

Example 1: Approximately 100 meshes of cowhide leather powder and polyamide heat-fusible adhesive powder (trade name: BRATAMID H1059-80, approximately 200 meshes, manufactured by Toagosei Kagaku Kogyo Co., Ltd.) were mixed in a 1:2 ratio. The mixed powder is mixed in a weight ratio, and the mixed powder is applied uniformly over the entire surface of the base fabric by a scattering method on a plain woven raised fabric, and then it is passed between rolls heated to 120°C and the pressure adjusted to 20 kg/crrt2 to integrate it. A leather-like substance was obtained.

Example 2 80 mesh of cowhide leather powder and polyurethane resin* powder were mixed at a weight ratio of 1:1, and the mixed powder was applied uniformly to the entire surface of the base fabric by a scattering method on a nonwoven fabric, and then this was 1
The mixture was passed through rolls heated to 20° C. and adjusted to a pressure of 7 kg/cIrL2, and integrated to obtain a leather-like material.

Next, 6017 m2 of urethane resin liquid with a viscosity of 70,000 centipoise (trade name: Honey Ace 661, manufactured by Honey Kasei Co., Ltd.) was applied to this surface, dried at 80°C for 5 minutes, and then applied at a pressure of 20 kg/crrt at room temperature. A leather-like material was obtained by passing through pressure rolls.

The moisture permeability of this thing is 1300? /m2・24 hours.

Comparative Example 2 80 mesh of cowhide leather powder and polyurethane resin powder were mixed at a weight ratio of 1:2, and the mixed powder was uniformly applied to the entire surface of the base fabric by a scattering method on a nonwoven fabric.
The mixture was passed through rolls heated to .degree. C. and adjusted to a pressure of 20 kg/d, and then integrated to obtain a leather-like material.

Comparative Example 3 In the method of Example 1, polyvinyl acetate latex (trade name Movinyl 120, manufactured by Hoechst Synthetic Co., Ltd.) was applied on the base fabric.
While this adhesive still has adhesive properties, approximately 100 meshes of cowhide powder was applied to the entire surface by electrostatic coating, a pressure of 2 kgA2 was applied, and then 30' i/m2 was applied at 110°C. After drying for a minute, a leathery material was obtained.

Performance tests were conducted on the leather-like materials obtained in Examples 1 and 2 and Comparative Examples 1 and 3, and the results shown in Table 1 were obtained.

Example 3 A leather powder coating was prepared in the same manner as in Example 1, and an ethylene-vinyl acetate copolymer latex (Movinyl, DM-10° Hoechst Synthesis) whose viscosity was adjusted to 10,000 centipoise with methylcellulose was coated on the surface. Co., Ltd.) was coated with a knife coater at 801/m2, dried at 100°C for 3 minutes, and then passed through a pressure roll whose temperature was adjusted to 120°C at a pressure of 15 kvcm2.

After that, the surface was further puffed, and a leather-like substance closely resembling natural leather was obtained.

The moisture permeability of this material was 950 V/m2, and it was a leather-like material with excellent scratch and abrasion resistance.

Comparative Example 4 The same method as in Example 3 was carried out except that an ethylene-vinyl acetate copolymer latex whose viscosity was adjusted to 4,000 centipoise was used.

The resulting leathery substance was hard and rough to the touch.

Claims (1)

[Claims] 1 Powder made by mixing natural leather powder of 30 mesh or less, which is obtained by crushing natural leather scraps into fibers, and heat-fusible adhesive powder of 30 mesh or less at a blending ratio of 1:1 to 2. After the mixture is applied onto a substrate and then passed through a heated pressure roll to form a leather powder coating layer, a thermoplastic resin liquid having a viscosity of 5,000 to 100,000 centipoise is applied onto the leather powder coating layer. The coating amount is 5 to 1 as resin solid content.
00L? /m2, moisture permeability 800? /m”・24 hours or more, and then pressure treated after drying.