JPH086265B2 - Wrinkled synthetic leather similar to natural leather and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to synthetic leather, particularly synthetic leather suitable for furniture sheet materials, and a method for producing the same.

[Conventional technology]

Conventionally, polyurethane synthetic leather has been used for various purposes because of its excellent texture and appearance. However, since most of the conventional polyurethane synthetic leathers use polyester polyurethane as the material, when used for a long period of time, the hydrolysis of the polyester polyurethane causes a long period of time such as furniture seats, vehicle seats, and high-class clothing. The product that needs to be used for a long time cannot be used at all.

Of course, it is possible to improve the properties to some extent by adding a hydrolysis inhibitor such as polycarbodiimide to the polyester polyurethane component, but it is not possible to expect substantial improvement.

[Problems to be solved by the invention]

On the other hand, polycarbonate polyester-based polyurethane is known as a polyurethane excellent in light resistance and hydrolysis resistance, but this requires an extremely complicated process in manufacturing, and the raw material is not general-purpose and expensive, so that For all laminates, especially those with fibrous substrate layers and microporous coating layers, it is economically expensive and practically difficult to form these layers with polycarbonate polyester-based polyurethane.

An object of the present invention is to provide a synthetic leather which has flexibility by utilizing the characteristics of the polyester-based polyurethane and has excellent texture, appearance and durability, and a method for producing the same.

[Means for solving problems]

The present invention is, (1) attachment woven, knitted, nonwoven, etc. fibrous tissue composed mainly of a polyether-based polyurethane and 100% modulus value 150~400kg / cm ² to polypropylene glycol polyol component fibrous tissue , A fibrous substrate layer impregnated to impart foldability to the fibers of the tissue by solidifying the components, and polytetramethylene glycol as the polyol component 10
A bond coat composed of a polyether polyurethane having a 0% modulus value of 15 to 50 kg / cm ² and forming a continuous film on the fibrous substrate layer, and a 100% modulus value of 200 to 600 kg / cm ²
Made of polycarbonate polyester-based polyurethane, which has a yield value and is laminated and integrated with a top coat for forming a continuous film on the bond coat, and synthetic leather capable of wrinkling like natural leather, and The method for producing this synthetic leather is as follows: (2) A fibrous base layer is formed by adhering and impregnating a fiber system with a polyether polyurethane having a polypropylene glycol as a polyol component and a 100% modulus value of 150 to 400 kg / cm ^2. Then, on the surface of the base layer, the fibrous base layer is made of a polyether polyurethane having a polytetramethylene glycol as a polyol component and a 100% modulus value of 15 to 50 kg / cm ² through a bond coat forming a continuous film. polycarbonate polyester Poriu having a surface and a yield value of 100% modulus value 200 to 600 kg / cm ² A method for producing a natural leather-like wrinkles possible synthetic leather, which comprises coating at topcoat continuous film consisting of Tan. According to the production method of the present invention, the obtained synthetic leather is subjected to a rubbing process to be provided with wrinkles similar to natural leather, so that the texture of the base material layer can be obtained.

[Principle / Action]

By using polyether polyurethane having polypropylene glycol as a polyol component, which is a cheap raw material, for polyurethane forming the fibrous base layer, and by substantially preventing ventilation to the fibrous base layer as a synthetic leather base, the synthetic The synthetic leather has excellent light resistance, hydrolysis resistance, and durability of the entire leather.

Polyether polyurethane is inherently poor in light resistance. Here, the polyether-based polyurethane refers to polyurethane having polypropylene glycol and / or polytetramethylene glycol as a polyol component. In particular, if the contact area with air is large, it is extremely susceptible to oxidative deterioration and deterioration due to ultraviolet rays.

Therefore, at least in order to improve the light resistance of the polyether polyurethane, the air supply to the fibrous base layer is blocked as much as possible, and the polyether base polyurethane layer having no hydrolyzable group is used. It is possible to improve the hydrolysis resistance by using polyurethane. Further, in order to improve the light resistance and the hydrolysis resistance, by laminating a continuous coating having an appropriate thickness on the surface of the fibrous base layer, synthetic leather having excellent durability can be obtained.
By changing the hardness of each constituent layer, a synthetic leather having a texture, feel, and wrinkles that closely resembles natural leather can be obtained.

 The present invention will be described below with reference to the drawings.

As shown in FIG. 1, the synthetic leather of the present invention comprises a fibrous substrate layer 1 in which fibers are impregnated with a polyether polyurethane having polypropylene glycol as a polyol component and polytetramethylene glycol as a polyol component. The bonding coat 2 is a continuous coating made of polyether polyurethane and the top coat 3 is a continuous coating made of polycarbonate polyester polyurethane.

The synthetic leather of the present invention comprises a fibrous substrate layer 1 impregnated with a polyether polyurethane having polypropylene glycol as a polyol component, and a bond coat 2 of a continuous film made of a polyether polyurethane having polytetramethylene glycol as a polyol component, It can be obtained by producing synthetic leather by laminating a continuous coating of a polycarbonate polyester-based polyurethane with a top coat 3 by a transfer method, and then subjecting the synthetic leather to rubbing.

 The configuration of the present invention will be specifically described below.

As the fibrous base material, woven cloth, knitted cloth, non-woven cloth or the like made of natural fibers or synthetic fibers is used, and this base material is impregnated with a polyether polyurethane elastomer containing polypropylene glycol as a polyol component. The preferred range of the 100% modulus value of the impregnated polyether polyurethane is 150 to 400 kg / cm ² . 100% modulus is 150 kg
If it is less than / cm ^2, it has a rubber-like texture, which is a drawback of polyether polyurethane, and a texture with a good drape cannot be obtained. When the 100% modulus value is 400 kg / cm ² or more, the rubber-like texture is not obtained, but the hard texture is not preferable. Impregnating a base material with a polyether-based polyurethane having a 100% modulus value of 150 to 400 kg / cm ² makes it possible for the polyurethane that has been impregnated and adhered to the fibers when the final product is subjected to a rubbing process to give breakability to the fibers. Each part of the above is folded and the texture of the fibrous base material is used to obtain a very soft and rich drape texture.
Impregnation amount of polyether polyurethane is based on fiber weight
It is preferably within 100%.

The bond coat 2 and the top coat 3 need to be processed into a continuous film without pinholes.

For the bond coat 2, a polyether polyurethane having polytetramethylene glycol as a polyol component is used. In addition to the colorant, an ultraviolet absorber, a radical scavenger, an antioxidant and the like can be added to the polyether polyurethane as required.

Further, a crosslinking agent having a polyisocyanate may be added to the polyether-based polyurethane used for the bond coat 2 if necessary for the purpose of improving physical properties such as solvent resistance and chemical resistance. It is necessary to determine the addition amount of the crosslinking agent in consideration of the hardness of the bond coat 2 and the balance with the feel of the synthetic leather as a whole.

The polyether polyurethane used for the bond coat 2 is
It must have physical properties with a 100% modulus value of 15 to 50 kg / cm ² . When the 100% modulus is 15 kg / cm ² or less, physical properties are weak and a practical synthetic leather cannot be obtained, and when it is 50 kg / cm ² or more, the texture becomes hard, and wrinkles are less likely to enter. Moreover, the wrinkles cannot be retained for a long time. The thickness of the polyurethane bond coat 2 is 10
If it is less than 10 μ, the physical properties are weak, and if it is more than 60 μ, the feel becomes hard, which is not preferable.

The top coat 3 must be a coating layer formed of polyurethane having excellent light resistance and hydrolysis resistance.

As a polyurethane generally used for a top coat, a polyester-based polyurethane obtained by adding an aliphatic or alicyclic diisocyanate to a polyester polyol obtained by reacting a glycol having 2 to 6 carbon atoms with a dibasic acid such as adipic acid Polycarbodiimide and other hydrolysis inhibitors, benzimidazole-based, benzophenone-based UV absorbers, phenol-based antioxidants, etc. can also be used, but the durability of the furniture sheet material of the present invention can be used. It is unsuitable for those requiring sex.

However, if only the hydrolysis resistance is to be improved, polytetramethylene glycol and polypropylene glycol can be sufficiently satisfied as the polyol component, but they cannot be used as a polyurethane for a top coat because of their extremely poor light resistance.

By the way, the fibrous base layer 1 and the bond coat 2 are extremely excellent in hydrolysis resistance and inferior in light resistance due to the characteristics of the polyol component, but such deterioration of each coating layer can be completely compensated. As a result of various studies on the raw materials for the polyurethane for the top coat, the polycarbonate polyester-based polyurethane was the most excellent and could completely satisfy the requirements.

As described above, a polycarbonate polyester-based polyurethane is used for the top coat, and a colorant, various additives and the like may be added to the polyurethane as required. Polycarbonate polyester polyurethane of Topcoat 3 has a 100% modulus value of 200-600kg / cm
It must be ² and have a yield value. If it does not have a yield value, wrinkles do not occur, which is not preferable. If the 100% modulus is 200 kg / cm ² or less, the wrinkles are hard to enter, and if the 100% modulus is 600 kg / cm ² or more, the wrinkles are included but the texture is hard, which is not preferable. The thickness of the top coat is 3 to
If it is less than 3μ, it is not possible to sufficiently suppress the deterioration of the polyether polyurethane of the lower layer, and there is substantially no wrinkling. If it is more than 10μ, the texture is Not only becomes hard, but also when wrinkles are added, inconveniences such as cracking in the top coat layer occur.

The polyether-based polyurethane and polycarbonate polyester-based polyurethane used in the present invention is a polymer of a polyether-based polyol or a polycarbonate polyester-based polyol, a diisocyanate compound and a chain extender, and the polyether-based polyol is generally polypropylene glycol or polytetrahydrofuran. Methylene glycol is used, and as the polycarbonate polyester-based polyol, 1,6-hexane polycarbonate-based polyol can be generally used.

As the diisocyanate compound to be reacted with the polyether polyol and the polycarbonate polyester polyol, tolylene diisocyanate, diphenylmethane diisocyanate, xylylene diisocyanate, tetramethylene diisocyanate, hexanemethylene diisocyanate, isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate and the like can be used.

Further, as a chain extender, ethylene glycol, 1,4-
Low molecular weight glycols such as butanediol, 1,6-hexanediol, neopentyl glycol, or piperazine, ethylenediamine, hexamethylenediamine, propylene-1,2-diamine, N-methyl-bis- (3-aminopropyl) amine Primary or secondary amines such as, 1,4-diaminocyclohexane, 1-amino-3-aminomethyl-3,5,5-trimethyl-cyclohexane can be used.

The top coat 3 and the bond coat 2 are laminated and integrated by the following steps. That is, the polycarbonate polyester-based polyurethane solution forming the top coat 3 is
After coating on a support having releasability, it is dried to form a pinhole-free continuous coating, and then the topcoat 3
A polyether-based polyurethane solution containing polytetramethylene glycol forming the bond coat 2 as a polyol component is applied thereon to form a continuous film in the same manner. After that, the surface on the side of the bond coat 2 of this laminated and integrated laminate is pressed onto the fibrous base layer 1 to complete the synthetic leather. The bond coat 2 and the fibrous base layer 1 It is preferable that the integration is carried out by utilizing the adhesiveness after volatilization of the organic solvent or the adhesive state at the time of thermocompression bonding from the viewpoint of maintaining surface smoothness and feeling.

By further rubbing the synthetic leather, fine folds are attached to each part of the fibrous structure of the base layer 1, which has an extremely soft and drape-rich texture, and is rubbed by rubbing. , Wrinkles can also be held for a long time.

The kneading can be performed by hand kneading or mechanical kneading, but in the case of mechanical kneading, the synthetic leather having a better texture can be obtained by heating the synthetic leather at 100 to 130 ° C. To be

〔The invention's effect〕

As described above, according to the present invention, a polyether-based polyurethane containing polypropylene glycol as a polyol component, which is economically advantageous for the polyurethane impregnated into the fibrous base material, is used to impart hydrolysis resistance and further bond. Polycarbonate-polyurethane polyurethane with excellent light resistance and hydrolysis resistance is used for the top coat, using polyether polyurethane with polytetramethylene glycol, which has good hydrolysis resistance as the polyol component, even if the coating has difficulty in light resistance. By changing the hardness of each constituent layer by using, it is possible to obtain a synthetic leather which is very similar in texture to the natural leather, feels, wrinkles and has excellent durability.

Further, according to the present invention, due to the synergistic effect of the polyurethane having a yield value formed in the outermost layer of the structure and the polyurethane impregnated into the fibrous base material, it is easy to get wrinkles, and by kneading, it is extremely soft and drapes. It has excellent properties and can keep creasing for a long time, so it closely resembles the appearance of natural leather, has excellent flexibility overall, has a texture that closely resembles natural leather, and has excellent long-term durability, especially furniture sheets. It is a synthetic leather suitable for long-term use.

〔Example〕

Examples of the present invention will be given below, but the present invention is not limited to these examples.

(Example 1) Thickness obtained by blending polyester fiber and cotton fiber.
70m / m double-sided fluffed cloth is impregnated with 100% modulus value 200kg / cm ² dimethylformamide solution of polyether polyurethane having polypropylene glycol as a polyol component (solid content 8.5%, containing 5 parts by weight of colorant), Polyurethane solids 35 per weight of fiber by squeeze roll
Squeeze to 20% of water, then soak it in water at 20 ℃, coagulate it, desolvate it, dehydrate it, and dry it under hot air at 120 ℃. A fibrous base material was obtained.

On the other hand, a 100% modulus 350 kg / cm ² 1,6-hexanediol polycarbonate-based polyurethane solution (solid content 12%, containing 5 parts by weight of colorant) having a yield value on a release paper with squeezing to a dry thickness of 5 μm. It was coated with a knife coater so that it was continuously dried with hot air in a dryer having a temperature gradient of 70 to 100 ° C. to obtain a top coat as a continuous film without pinholes.

Further, as a bond coat on the top coat, 100
Polyether-based polyurethane solution containing polytetramethylene glycol with a% modulus value of 30 kg / cm ² as a polyol component (solid content 30%, cross-linking agent 7 parts by weight, colorant 20 parts by weight) to a dry thickness of 30μ Was coated with a knife coater and dried with hot air at 100 ° C., and while the bond coat had tackiness, the fibrous substrate was thermocompression bonded onto the bond coat surface to be integrated. After the binding coat was cured, the release paper was peeled off to obtain a synthetic leather having a thickness of about 0.70 m / m. In this state, the obtained synthetic leather had no drape and was extremely hard to the touch.

Furthermore, by mechanically rubbing the synthetic leather while heating it in an atmosphere of 110 ° C, the texture is soft and has drapeability, and the wrinkles are retained for a long period of time. The synthetic leather of was obtained. This synthetic leather was excellent in durability such as hydrolysis resistance and light resistance, and was suitable as a furniture sheet material and the like.

This synthetic leather sheet material did not show any change in appearance, texture and physical properties even after 10 weeks in an atmosphere of relative humidity 90% and temperature 70 ° C. Furthermore, no change in appearance, texture, or physical properties was observed even after an ultraviolet irradiation test was carried out at 63 ° C with a fade meter for 200 hours.

(Comparative Example 1) Example 1 except that the 100% modulus value of the impregnated polyether polyurethane was changed to 40 kg / cm ^{2 in} Example 1.
Processed in the same manner as above to obtain synthetic leather. However, although the synthetic leather had a soft texture, the rubber elasticity was so strong that no wrinkles remained and it was different from the object of the present invention.

[Brief description of drawings]

 FIG. 1 is an enlarged sectional view showing the basic structure of the present invention. 1 ... Fibrous substrate layer, 2 ... Bond coat 3 ... Top coat

Claims (2)

[Claims] 1. A woven fabric, knitted fabric, mainly the fibrous tissue of the non-woven fabric, etc., adhering the polyether-based polyurethane and 100% modulus value 150~400kg / cm ² for polypropylene glycol and the polyol component in the fiber tissue, impregnation And a fibrous substrate layer that imparts foldability to the fibers of the tissue by coagulation of the components, and is composed of a polyether-based polyurethane having a polytetramethylene glycol as a polyol component and a 100% modulus value of 15 to 50 kg / cm ² , Bond coat to form a continuous film on a solid substrate layer, 100% modulus value 200-600k
Polycarbonate polyester-based polyurethane of g / cm ² , which has a yield value and is characterized by being laminated and integrated with a top coat that forms a continuous film on the bond coat. leather. ^2. A fibrous base layer is formed by adhering and impregnating a fiber structure with a polyether polyurethane having a polypropylene glycol as a polyol component and a 100% modulus value of 150 to 400 kg / cm ² , and then, on the surface of the base layer. Polyether methylene glycol as a polyol component 100% modulus value 15 to 50 kg / cm ² consisting of polyether polyurethane, 100% modulus value 200% of the surface of the fibrous substrate layer through a bond coat forming a continuous coating. ~ 600 kg / cm ²
And a method for producing wrinkle-like synthetic leather similar to natural leather, which comprises coating with a continuous topcoat of a polycarbonate polyester polyurethane having a yield value.