JPH0345785A - Synthetic leather - Google Patents

Abstract

PURPOSE:To obtain synthetic leather having more excellent water resistance and durability than natural leather and excellent water vapor transmission and water absorption by coating nonwoven fabric, etc., with a synthetic resin solution blended with mixed powder of silk powder and natural leather powder. CONSTITUTION:Mixed powder of silk powder and natural leather is blended with a synthetic resin to give a mixed resin solution, which is applied to a substrate such as nonwoven fabric, dried and a pore-free coating film is formed or the substrate is immersed in a coagulating bath and a porous coating film is formed to give synthetic leather exceeding natural leather in microorganism resistance, having excellent flexibility and water vapor transmission.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to synthetic leather that is soft to the touch and highly moisture permeable.

(Prior Art) Conventionally, in order to impart moisture permeability and water absorption to synthetic leather made of a resin film such as polyurethane resin, a foaming agent was added to the synthetic resin material to make it porous.

Recently, attention has been focused on the moisture absorption and desorption properties of natural leather, and attempts have been made to impart these properties by mixing natural leather powder or gelatin powder into synthetic resin materials. (For example, JP-A-63-152483) (Problem to be solved by the invention) However, after applying a resin film made only of synthetic resin material to a base fabric such as non-woven fabric, the film layer is immersed in a coagulating liquid. Synthetic leather that has been formed or has a resin film attached thereto has a drawback in that its functionality, ie feel, or texture is not as good as natural leather. To compensate for this drawback, natural leather powder or gelatin is mixed in. If the resin film is to have the feel of natural leather, a certain amount of natural leather powder must be mixed in. However, as a result, the strength of the resin film becomes weak and the surface strength of the synthetic leather product decreases, so the amount added has necessarily been regulated. This is because the resin gathers around the leather particles, making them look like aggregates coated with resin, and the resin layer becomes irregularly discontinuous, resulting in the formation of a locally weak film. Therefore, it is necessary to apply a mixed resin liquid of leather powder to a base fabric such as a non-woven fabric and then immerse it in a coagulating liquid to form a film layer, or to add a resin film made from the mixed resin liquid. Bonded synthetic leather has poor flexibility and abrasion fastness.

(Means for Solving the Problems) The characteristic means of the present invention is to create a mixed resin liquid by mixing a mixed powder obtained by adding natural leather powder to silk powder with a synthetic resin, and to directly apply this mixed resin liquid to a nonwoven fabric. After applying it to the base fabric, it is immersed in a coagulating solution to form a film layer, or
Alternatively, a resin film is made using a synthetic resin mixture, and this is attached and adhered to a base fabric such as a nonwoven fabric to produce synthetic leather with a soft texture and high moisture permeability.

(Function) When natural leather powder is added and mixed with silk powder and dispersed in resin, microscopically, the silk powder has a mixture of spiral particles and irregularly shaped fine particles. When this is dispersed in a resin, natural leather powder and irregularly shaped fine particles of silk enter the spiral intertwining, and the resin acts as an adhesive to connect them, forming appropriate bubbles and stretching them into a film. Since the resin layer is dispersed, it is difficult for the resin layer to become discontinuous, and even if the amount of silk powder mixed in is increased, the rate of brittleness is small. Synthetic leather made using this mixed resin liquid has a calm color tone, is excellent in static electricity resistance and moisture permeability, and has a feel similar to that of natural leather. Furthermore, you can freely change the color tone, texture, and feel of the leather by changing the proportion of natural leather powder added to the silk powder.For example, adding more silk powder will result in synthetic leather that is more flexible and has a warmer feel. As the amount of natural leather powder added increases, the cool feel of natural leather is obtained, and by combining these properties, it is possible to obtain synthetic leather with skin properties that surpass those of natural leather.

(Effects of the Invention) As described above, according to the present invention, it has become possible to supply a large amount of synthetic leather products that have the advantages of natural leather and surpass natural leather in feel compared to conventional products. In other words, if you make synthetic leather by mixing a mixture of silk powder and natural leather powder with synthetic resin, the silk powder will not aggregate with each other and will be distributed in a uniformly dispersed state. By increasing the amount of powder according to the purpose, it has a texture, excellent moisture permeability, water absorption, non-static properties, and has properties superior to natural leather in terms of water resistance, durability, antibacterial properties, etc. We can provide synthetic leather with

(Example) Next, examples will be shown.

Silk noil was put into a pressure vessel equipped with a heating jacket, and 4 kg/cal of steam was simultaneously supplied into the vessel and the jacket. First, the air inside the vessel was replaced with steam, and then the vessel was sealed and heated for about 10 minutes. After the interior of the silk Mi fabric was sufficiently swollen in this manner, the outlet of the pressure vessel was opened all at once to cause swelling due to rapid pressure reduction. This was dried until the moisture content was around 5%, and then ground in a media agitation type grinder, with an average particle size of 15 μm.
A polyurethane resin liquid containing 40% of a powder mixture of natural leather powder with an average particle size of 30 μm obtained in a 5:1 ratio obtained in a similar manner to the silk powder of M was uniformly applied onto the nonwoven fabric. After that, the synthetic leather obtained by immersing it in a coagulation bath, washing with water, and drying has the cross-sectional structure shown in Figure 1, and has a seam of three meshes of silk powder with a spiral particle shape. The resin ■ in which silk powder ■ and natural leather powder ■ are uniformly dispersed enters the fibers of the base fabric ■
In addition to adhering this resin layer, the spaces created when the solvent contained in the mixed resin liquid escapes during solidification remain as air bubbles due to the action of silk powder ■ and resin ■, providing moisture permeability and water absorption. There is. The synthetic leather obtained in this way has the same visual and tactile properties as natural leather, is moisture permeable and absorbent, is soft to the touch, has a calm color tone, and can be post-dyed. It has a cool characteristic that natural leather does not have. The mixing ratio of the mixed powder, which is made by adding natural leather powder to silk powder, is 1 by weight.
Good synthetic leather could be obtained in the range of 0 to 80%.

In addition, as the base fabric used, instead of non-woven fabric, woven fabric, floor leather, artificial leather semi-finished products, synthetic leather semi-finished products produced by wet process, etc. can be used to obtain synthetic leather with further improved physical properties and functions.

(Another Example) The present invention is made by applying a polyurethane resin liquid containing 50% of a mixture of the same silk powder as above and adding natural leather powder to a release paper, and adhering the resulting resin film to a nonwoven fabric. Synthetic leather has characteristics such as being highly moisture permeable and absorbent, dry to the touch, and having a calm color tone. Furthermore,
This does not preclude the use of sanding to remove a thin layer of resin from the surface in order to give the surface a more distinctive feel.

[Brief explanation of drawings]

FIG. 1 is an enlarged cross-sectional view of an embodiment of the present invention. In the diagram, 1 is silk powder (spiral), 2 is silk powder (fine powder), 3 is natural leather powder, 4 is resin, 5 is air bubbles, and 6 is the fiber of the base fabric.

Claims (1)

[Claims] Synthetic leather is characterized in that a synthetic resin film is formed from a synthetic resin liquid mixture prepared by mixing a powder mixture of silk powder and natural leather powder.