JPS5917228B2 - Artificial leather with excellent high frequency processability - Google Patents

Description

[Detailed description of the invention] The present invention relates to artificial leather with excellent high frequency processability.

Artificial leather consisting of a base layer and a paint layer is well known and is widely used in shoes, bags, clothing, furniture, etc. as a substitute for natural leather. Various processing methods suitable for artificial leather have also been developed, and recently, attempts have been made to use high frequencies to bond artificial leather together or to shape artificial leather. However, conventional artificial leather, especially black-finished products and dark-colored finished products that mainly use carbon black, have a non-insulating metallic finish because the carbon black is generally conductive. When high-frequency processing is performed using a high-frequency processing electrode made of a mold, sparks are likely to occur when high-frequency waves are applied, resulting in the formation of holes in the artificial leather. The present inventors have conducted intensive research to obtain artificial leather free from the above-mentioned drawbacks, and have discovered that artificial leather having a paint layer with a high electrical resistance value is suitable for this purpose, and have arrived at the present invention. That is, the present invention provides an artificial leather consisting of a base layer and a paint layer mainly composed of carbon black, in which the paint layer has a volume resistivity of 1012 Ω. It's leather.

The base layer in the present invention refers to fabrics such as nonwoven fabrics, woven fabrics, and cotton fabrics (including those impregnated with elastic resins such as polyurethane) formed from fibers such as cotton, rayon, nylon, and polyester, and these fabrics. A porous resin layer made of elastic resin such as polyurethane is formed on top.

The paint layer in the present invention refers to a layer formed on the base layer by a '0 coating method or a lamination method.

The paint layer may be, for example, one consisting only of a colorant mainly composed of carbon black and a colored resin layer mainly composed of resin (hereinafter referred to as the first paint layer), or a layer mainly composed of resin (hereinafter referred to as the first paint layer) on top of the first paint layer. A two-layer structure in which a second paint layer (hereinafter referred to as the second J5 paint layer) is formed, or a colored resin layer (hereinafter referred to as the third paint layer) consisting mainly of a colorant and resin is further formed on the second paint layer. There are also those with a Ξ layer structure. The third paint layer is partially formed on the second paint layer and
It may also be formed directly on the base layer. Additionally, additives such as softeners, stabilizers, and antistatic agents may be mixed into the paint layer. In the present invention, the volume resistivity of the paint layer is 1012 Ω·or more, preferably 101
Must be 3 ohms or more than 5 ohms.

If it is less than 1012Ω・I, when applying high frequency through a high frequency machining electrode made of a non-insulating metal mold,
Since sparks are likely to occur, the object of the present invention cannot be achieved.

If the paint layer consists of a first and second paint layer, or a first, second, and third paint layer, each paint layer has a resistance of 1012Ω. It must have a volume resistivity value of or above. In addition, the volume resistivity value of the paint layer in the present invention is approximately 60 mm thick from the resin forming the paint layer or the colorant mainly consisting of resin and carbon black.
This value was measured by forming a film of 0μ. The coating layer can be formed, for example, by directly coating the base layer with an organic solvent solution or dispersion of a resin or a colorant mainly consisting of a resin and carbon black using a gravure roll or knife coater, or by separating such a solution or dispersion. After coating a paper pattern or polyester film to form a film, this film is laminated on a base layer,
Method of adhering to the base layer using heat, pressure, adhesive, etc. (
It is formed by a lamination method). Volume resistance value is 10
Preferably used resins to form a coating layer having a resistance of 12 Ω.multidot. or more include polyurethane resins, polyvinyl chloride, polyamides, and polyacrylic acid resins. The coloring agent may be mainly carbon black as described above, with various pigments and dyes added thereto. When used, the volume resistivity of the paint layer is 10.
In order to satisfy the condition of 12 ohms or more, the resin and the combination of the resin and the coloring agent, which is mainly composed of carbon black, must be appropriately selected. As the resin, a polyurethane resin is particularly preferred, and a combination of a polyurethane resin and carbon black is particularly preferred. As will be clear from the examples below, high-frequency processing in the present invention refers to a method of forming a mold on the surface of artificial leather by applying high-frequency waves using a high-frequency processing electrode made of a non-insulating metal mold. It refers to mold processing, processing in which coloring is applied to the applied area at the same time as application, and adhesive processing in which artificial leather is overlapped and fused together.

These processes are not limited to only one time, but also include cases in which the same location is processed two or more times. The high frequency machining conditions include an output of 1 to 10kW, a frequency of 41.14MHz1 or 27
．． It is appropriate that the applied current of 12 MHz is 200 to 800 rn, the applied time of A1 is 1 to 10 seconds, and the pressing force is 1 to 10 kg/d. The present invention will be explained in detail with reference to Examples below.

Parts in the examples mean parts by weight. Example 1 In the nonwoven fabric layer of the polyester fiber nonwoven fabric, Jif? On the surface of a sheet obtained by adding nilmethane-4,4'-diisocyanate-aliphatic polyester polyurethane resin in a solid content of 65% of the weight of the nonwoven fabric, a polyurethane resin of the same composition was added in a solid content of 200 f7/M2. A porous layer was formed by coating the base layer.

On this base layer, carbon black (Ss-6701B
1ack1 manufactured by Dainichiseika) 20 parts, diphenylmethane 14
, 4'-diisocyanate-aliphatic polyester polyurethane resin 4.0 parts and tetrahydrofuran/dioxane/dimethylformamide (weight mixing ratio 40/40/
20) A first paint layer was formed by applying 40 parts of paint to a solids thickness of 15 μm.

Next, a paint consisting of 45 parts of dicyclohexylmethane-4,4'-diisocyanate aliphatic polyester polyurethane resin and 55 parts of tetrahydrofuran/dioxane/dimethylformamide (weight ratio 30/40/30) was applied so that the solid content was 5 μm thick. A second paint layer was formed. The artificial leather thus obtained is used as artificial leather (4
). The paints used for the first paint layer and the second paint layer are each applied onto a glass plate, and after drying, the thickness is 0.6m.
/m paint film was obtained and used for measuring electrical resistance.

Using artificial leather (4), high frequency bonding was performed between the artificial leather particles and the results are shown in Table 1.

Comparative Example 1 Carbon black (
Seika Seven UST279OBlackl made by Dainichiseika)
25 parts, dicyclohexylmethane-4,4'-diisocyanate-aliphatic polyester polyurethane resin 40
and 35 parts of tetrahydrofuran/dioxane/dimethylformamide (mixing ratio by weight 40/40/20) to a solid content of 15 μm.
A first paint layer was formed.

Next, a paint consisting of 45 parts of dicyclohexylmethane-4,4'-diisocyanate-alicyclic polyester polyurethane resin and 55 parts of tetrahydrofuran/dioxane/dimethylformamide (weight ratio 30/40/30) was applied to a solid content of 5 μm thick. The artificial leather obtained by applying the coating to form a second paint layer and softening it is called artificial leather (B).
shall be.

The paints used for the first and second paint layers were each applied onto a glass plate, and after drying, a paint film with a thickness of 0.6 m/m was obtained, which was used to measure electrical resistance. Using artificial leather (B), high frequency adhesive processing was performed in the same manner as in Example 1, and the results were summarized in the first example.
Shown in the table.

Example 2 20 parts of carbon black (Ss-6701 formerly @Ckl manufactured by Dainichiseika), 40 parts of diphenylmethane-4,4'-diisocyanate-aliphatic polyester polyurethane resin, and tetrahydrofuran/dioxane/dimethylformamide (weight mixing ratio 40/ 40/20) A third coating layer was formed by applying 40 parts of the coating material to a solids thickness of 5 microns on a polyester film foil.

The surface of this film and the surface of the base layer obtained in Example 1 were superimposed and fused using a high frequency processing machine, and then only the polyester film was peeled off. A clear mark colored black was formed on the base layer. The artificial leather thus obtained was used as artificial leather (referred to as 0). The paint used for the third paint layer was applied onto a glass plate, and after drying, a paint film with a thickness of 0.6 m/m was obtained and used for measuring electrical resistance. there was.

Table 1 shows the high frequency processability when obtaining artificial leather C).

As shown in Table 1, the volume resistivity of the paint layer is 1012
This shows that artificial leather with a value of Ω・I or less has poor high frequency processability.

The volume resistance value was measured using a pipe-rating reed electrometer (Vibrating Reed Electrometer).
ctrOmetcr) (Takeda Riken, TR-84M type)
Measured at

High frequency processing was performed under the following conditions.

Claims (1)

[Scope of Claims] 1. Artificial leather made of a base layer and a paint layer mainly composed of carbon black, which has high frequency processability, characterized in that the paint layer has a volume resistivity of 10^1^2 Ωcm or more. Excellent artificial leather. 2. Artificial leather with excellent high-frequency processability according to claim 1, wherein the paint layer has a volume resistivity of 10^1^3 Ω·cm or more.