JPS5936714B2 - Improved suede-like artificial leather - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a suede-like artificial leather having improved durability, daily chemical resistance, and elegant napping.

The present inventor has already proposed a suede-like artificial leather having raised naps made of ultrafine fiber bundles by impregnating an elastomer with a polymeric elastomer and applying para-ink to the entangled sheet of ultrafine fiber bundles, and is well known.

These products have many features such as excellent napping, easy care, multicolor and fastness, lightness, and high processing yield, and are far superior to natural suede. It is also known that it is widely praised as a place with many superior characteristics.

In particular, ultra-fine napped suede-like artificial leather made mainly of polyester has the unique Young's modulus, napped state, stiffness, dimensional stability, non-hydrophilicity, good dyeability, and ease of making raw materials of oriented polyester polymer. Because of its ease of availability, it has been evaluated as having excellent properties different from polyamides and the like.

However, the more elegantly raised naps are required for the polymeric elastic material used for this purpose, the more restrictions are placed on the polymer. This is because the resulting product is para-inked and dyed, and the adhesion between the fibers and the elastic body, the degree of blending, etc., make the fibers easier to cut, the elastic body easier to cut, and the ease with which they slip. difference,
This is because there is a delicate and complex relationship with the elastic material's ability to withstand dyeing (high temperature and moist heat). It is not just the materials alone that are important, but also their interrelationships. Therefore, it goes without saying that the relationships between polyester-based materials and polyamide-based materials are different. For products made mainly of polyester fibers, polyurethanes containing polyether polyols, such as polyurethanes mainly containing polytetrahydrofuran, give good naps, and the resulting products have strong repulsion properties. It is excellent because it has

As a result, extremely superior suede-like artificial leather is obtained. However, even with these excellent products, the demands for expanded applications, long-term use, and durability against chemicals used on a daily basis are becoming more and more sophisticated. I don't know where to stop. In response to many of these demands, the present invention aims to provide a more improved suede-like artificial leather, and furthermore, to provide an artificial leather having more elegant raised naps.

The object of the present invention is achieved by adopting the following configuration.

A fiber composite sheet with naps mainly composed of polyurethane and polyester ultrafine fibers of 0.5 denier or less, wherein the polyurethane has a molecular weight of 1,000 to 5,000.
0 polycaprolactone-based glycol or polyhexane adipate-based glycol, 4,4'-methylene bis(cyclohexyl isocyanate), and 4,4/-methylene bis as a bifunctional active hydrogen compound. An improved suede-like artificial leather characterized by being made of polyurethane formed by reaction with (cyclohexylamine) as a main component.

The artificial leather according to the present invention exhibits the following effects as a composite.

(1) Suede-like artificial leather with less photodeterioration and yellowing caused by light could be obtained.

In other words, we succeeded in increasing the durability in terms of light resistance deterioration. (2) It was possible to create a suede-like artificial leather that is less discolored and deteriorated by automobile exhaust gas and NOx gas.

(3) Hair conditioners, detergents, perfumes, water containing chlorine, bleaching (
We have succeeded in improving the durability of everyday chemicals such as bleaching products.

(4) We have succeeded in creating suede-like artificial leather that has high practical durability, including resistance to weathering, and is resistant to peeling.

This can be clearly seen if you use it for a long time, for example on the handle of your bag. (5) Despite the use of isocyanate containing no benzene rings or polyurethane using a chain extender, we succeeded in creating a composite sheet with little permanent spread and resistance to spread.

Furthermore, it has become even more effective when combined with a hub using a smoothing agent and fluffing using raised hair.

(6) With the polyurethane conventionally used for products that mainly use polyester fibers, it is difficult to generate good naps due to the hub ink, and most of the fibers break, so it is possible to obtain a good suede-like artificial leather. This was thought to be completely hopeless, but by using the present invention, which uses a specific polyurethane, we succeeded for the first time in producing long, suede-like naps. (7) Succeeded in producing dense piloerection.

(8) Succeeded in producing shiny and elegant raised hair.

(9) Succeeded in making nap naps less frizzy, especially with less frizz over time or after washing. 00) Succeeded in improving durability against brush abrasion (durability shown when rubbed with a brush such as ASTM D-1175).

(Own) also succeeded in reducing hub weight loss using hub ink.

We were able to create an elastic body with little photodeterioration.

A3) It is especially good if the hub is treated with a slippery oil before or at the time of the hub, so there is no need to consider the relationship with the impregnation of the polymeric elastomer at all. (In this case, the oil may get mixed into the coagulation bath, which may cause the quality of the next rod to vary, or may get mixed into the polymer elastic body fluid, which may cause quality variations.) There is no fatal drawback from an industrial perspective such as mixing in the equipment circuit.) A4) After making the composite sheet, the length and condition of the nap can be changed at any time to meet the fabric requirements. It got easier. (It does not have long hairs coming out from the front of the hub, but short hairs can be lengthened later, so it can be adjusted arbitrarily to suit the needs of the market, such as long hairs, short hairs, and anything in between. ) Hereinafter, one preferred method for producing the suede-like sheet according to the present invention will be explained by way of example.

The explanation will be given almost in order of process. In the present invention, ultrafine fiber-generating fibers are preferably used, in which bundles of ultrafine fibers can be obtained by physical treatment or chemical treatment.

It doesn't matter what the manufacturing method is. Moreover, the ultrafine fibers mainly have a denier of 0.5-0.003. Preferably, the main portion is 0.3-0.05 denier. Ultrafine fibers are easily cut by hubs and napping (along with polyurethane), but on the other hand, they have good napping. If it is too thick, it will look grainy, and if it is too thin, the color development will be poor. Also, if it is too thin,
Easy to break when hub or brushed (along with polyurethane).
The main polymer used in the present invention is mainly polyester fibers such as polyethylene terephthalate and its modified polyester. A typical example of the microfiber-generating fiber is a polymeric interlayer fiber.

Power is not limited to this. Sometimes they are peelable and split fibers, and sometimes they are special polymer blend fibers. Typically such fibers are drawn and molecularly oriented. Using such fibers, fiber entangled bodies such as raised knitted fabrics, napped woven fabrics, needle bunch nonwoven fabrics, etc. are formed.

The finer and higher the degree of entanglement, the better the suede-like appearance. Next, it is sometimes processed to generate ultra-fine fibers by hubbing or raising, but usually it is processed to remove one component.

In order to make the curl more dense and to improve the texture, it is preferable that the fabric be shrunk before that. Preferably, the shrinkage is carried out at 80 to 100°C. Shrinkage and division may be promoted with the help of chemicals. Now, as a binder, polyurethane is impregnated with a solution.

In this step, a specific polyurethane is used, and polyurethanes that are "mainly" polyols such as polytetrahydrofuran, polyethylene adipate, polybutylene adipate, polyethylene glycol, and polypropylene glycol are not used. This is because they are inferior in any of the following points: pilastering properties, dyeing resistance, durability, light resistance, exposure resistance (to water containing chlorine, etc.), hair styling product resistance, melting point hydrolysis properties, and the like. In the present invention, C6 polyester,
A diol called C6-C6 polyester is limited as the main component of the polyol in polyurethane polymerization.

Particularly preferred is a C6 type in which the directions of the ester bonds match. The C6 type is called a polycaprolactone type glycol that is specially synthesized so that both terminals are 0H.
The C6-C6 type is a polyhexane adipate type glycol.

Glycols "based" on these compounds can also be used in the present invention. The molecular weight of these is preferably 1,000 to 5,000 from the viewpoint of physical properties.
Particularly preferably 1,500 to 3,500.

Preferred diisocyanate which is the next main raw material in the polyurethane forming reaction is 4,4'-methylenebis(cyclohexyl isocyanate). It is particularly preferred because of its resistance to discoloration.

As is generally practiced, it is standard to use about twice the molar amount of the polyol.

There are times when it is used nearly 10 times more on special occasions, but it becomes too hard. The bifunctional active hydrogen compound (chain extender) is ethylene glycol, butylene glycol, hydrazine, or a diamine having a benzene ring or cyclohexane ring, and this amine mainly contains one component selected from those directly connected to the ring. It is preferable to use it as a component.

The present invention is based on P,P'-methylenebis(cyclohexylamine).

When used in combination with other substances, the above substances (eg hydrazine) are preferred. This limited number of chain extenders is also known as a single component, but its overall meaning up to the composite sheet is completely different.

It is preferable that the reaction be carried out under conditions in which a standard equivalence relationship is established as much as possible. When the molar ratio to the polyol is increased (to 3 to 5) in relation to the melting point during dyeing, it is done within a range that does not deteriorate the hand. These are used in the form of solutions such as dimethylformamide, lithium chloride additive solution, dimethylacetamide, and N-methylpyrrolidone, and these four types are particularly preferred.

The application concentration is particularly preferably applied as a solution in the range of 10% to 18%.

This has an extremely important meaning in terms of physical properties, napping properties, etc., especially when the solution directly contacts ultrafine fiber bundles mainly composed of polyester and is coagulated in that state.

The impregnated sheet is wet coagulated and desolventized. When a glue is used, active removal occurs at least when solidification is sufficiently advanced. In addition, in specific cases where sea-island type fibers are used when sea components are large, polyurethane is applied after removing the sea components, or when polyurethane is applied to peelable fibers, polyurethane is impregnated when the sea components are not removed. It should be noted that the bonding state of the fibers and polyurethane is quite different from that in the case where the fibers and polyurethane are bonded.

If I were to look for something else, I would say that in the case of peelable fibers, the situation is completely different when a glue is applied directly to the raised sheet or to a nonwoven fabric from which sea components are not removed, and then a polyurethane solution is immediately applied. .

In any case, the bond between the fiber and binder is too good,
If it is difficult to get a good nap due to the hub or raised material, which has good conformability and is hard to slip, apply an appropriate amount of a smoothing agent or a release lubricant such as silicone (polyorganosiloxane or its modified product) to improve the hub and napping. When the nap is raised, the nap becomes graceful and has a soft touch, the surface becomes smooth, and the nap becomes long, which is particularly effective in carrying out the present invention.

The suede-like artificial leather obtained in this way surprisingly has excellent durability (resistance to tearing and peeling), practicality, is dense, and has no "irritability" (the color of the polyurethane base is raised). It has been found that the hair has the above-mentioned functions and effects, such as being able to obtain raised hair that does not look dirty between the hairs, is glossy and elegant, has little frizz, is resistant to washing, and is resistant to hair styling products.

These are the results of a comprehensive intertwining of factors such as fibers, binders, their conditions, and lubricants such as silicone, and are completely unpredictable. The product of this invention is
It is effectively used for furniture such as upholstery, wall coverings, decorations, various clothing, and industrial materials.

Next, examples according to the present invention will be shown together with comparative examples, but the effectiveness of the present invention is not limited or limited by these in any way, but rather brings about the following applications, expansions, and developments. 6.

Example 1 A sea-island type fiber in which the sea component is polystyrene and the island component is polyethylene terephthalate, the island component is dispersed in the sea component, and the island component is continuous in the fiber axis direction, and the sea-island ratio is 5.
0/50, number of islands 16, denier of sea-island type fiber 3.2d,
The number of crimps is 12/inch, the cut length is 51 dragons, and a web is formed using the cross-slave method, 3000 pieces/d.
An entangled nonwoven fabric having a basis weight of 5109/M2 and an apparent density of 0.189/CTl was obtained by needle bunching.

Furthermore, when this nonwoven fabric was shrinked in hot water at 97 to 100°C, the basis weight and apparent density were 82, respectively, in the dry state.
39/M2, 0.3259/d. Next, this nonwoven fabric was impregnated with a polypynyl alcohol solution with a degree of saponification of about 88% to the sea-island fibers so that the solid content was 40 parts, and after drying, the sea component was reduced to 99.5 parts using trichlorethylene. % removed. In this sea-free nonwoven fabric, the polyol component is polycaprolactone (molecular weight approximately 2000), and the isocyanate is 4,4/-methylenebis, cyclohexyl isocyanate (a) CN<}CH2 diagram? NCO),
Polyurethane (25°Q25% viscosity 190p0ise) whose chain extender is 4,4'-methylenebis, cyclohexylamine (H2N constant The island component fibers were impregnated with 64 parts of formamide solution as a solid content, and subjected to water bath coagulation and removal of polyvinyl alcohol (simultaneously removal of dimethylformamide).

The basis weight and apparent density of the intermediate product at this time are 6229/M2 and 0.311g/CTlt in the dry state, respectively.
It was hot. Next, this intermediate product is made of polyorganosilicone (Toray Silicone SH-) that has a mold release or sliding effect.
7036) 2.5% emulsion liquid when wet.
% and dried at 110-120°C. The dried silicone-treated cloth was divided into two thicknesses using a slicing machine to obtain two intermediate products, and the non-sliced side was passed through a hub machine to form a nonwoven fabric having a raised side. Finally, using disperse dye 12
The product was pressure-dyed silver at 5°C to a beige color, and then cleaned at 70-80°C with a solution containing hydrosulfide and dried at 90°C to obtain a product. The finished product was a suede-like product with a luxurious feel in both surface quality and feel.

In addition, compared to the polyurethane used as a comparative product, products made from this polyurethane were superior in that they showed extremely little discoloration due to light and gases containing nitrogen oxides, and less physical property deterioration due to light and automobile gases. . The comparative product is a polyol mainly composed of polytetrahydrofuran (containing 10% polyethylene adipate), 4,4/-
This product uses polyurethane consisting of diphenylmethane diisocyanate and methylene bisaniline. Table 1 shows the characteristics of the product according to the present invention and the comparative product.

(Incidentally, if a UV absorber such as 2(2'hydroxy 3', 5' dimethyl or dibutylphenyl) 5 chlorobenzotriazole is added to the polyurethane of the present invention, it will be further stabilized against light. (Needless to say.) Example 2 A sea-island type fiber in which the sea component is copolymerized polystyrene of 2-ethylhexyl acrylate, the island component is dispersed in the sea component, and the island component is continuous in the fiber axis direction, and the sea-island ratio is 50. /5
0) Cut cotton with 36 islands, sea-island fiber denier 3.0d, crimp count 15/inch, and length 51 cm is formed into a web using the cross rubber method, and the fabric weight is 550 g/m with 3000 needle bunches. ', apparent density 0.219/C
A rlt entangled nonwoven fabric was obtained.

Furthermore, when this nonwoven fabric was subjected to hot water shrinkage at 85°C, the basis weight and apparent density were 8469/m' and 8469/m', respectively, in the dry state.
It became 0.3381/Crlt. Next, this nonwoven fabric was impregnated with a polyvinyl alcohol solution having a degree of saponification of 88% to the sea-island fibers so that the solid content was 37 parts.
After drying, use trichlorethylene to remove 99% of the sea component.
% or more was removed.

The polyol component of this sea-removed nonwoven fabric is polyhexane adipate glycol (molecular weight approximately 2000) obtained from hexamethylene glycol and adipic acid, the isocyanate is 4,4'-methylenebis, cyclohexyl isocyanate, and the chain extender is 4,4 '-Polyurethane consisting of methylenebis, cyclohexylamine (25℃, 25%
A dimethylformamide solution containing lithium chloride with a viscosity of 220 p0ise) was added to the island component fibers at a solid content of 5.
It was impregnated in two parts, coagulated in a water bath, and processed to remove polyvinyl alcohol (and simultaneously remove dimethylformamide).

The basis weight and apparent density of the intermediate product at this time were 643θ/m' and 0.322g/d, respectively, in a dry state. Next, this intermediate product is made of polyorganosilicone (Toray Silicone SH-7) that has a releasing or slipping effect.
036) 1.5% emulsion liquid is about 150% wet.
It was impregnated and dried at 110-120°C.

The dried silicone-treated fabric was divided into two thicknesses using a slicing machine to obtain two intermediate products, and the non-sliced side was mainly passed through a hub machine to form a raised sheet. Finally, pressure dyeing was performed using a disperse dye at 125°C to a beige color, and then 70°C.
After reduction cleaning with a solution containing hydrosulfide at ~80°C, the product was dried at 90°C. This product was a suede-like product that was softer than that of Example 1, had a good surface touch, and had a luxurious feel.

Further, it was exactly the same as Example 1 in that there was very little discoloration due to light and gases containing nitrogen oxides, and that there was little deterioration of physical properties due to light, hair styling agents, etc. Table 2 shows the characteristics of the product according to the present invention and a comparative product (a product using the same polyurethane as the comparative product of Example 1).

Claims (1)

[Claims] 1 A fiber composite sheet having naps mainly composed of polyurethane and polyester ultrafine fibers of 0.5 denier or less, the polyurethane having a molecular weight of 1,000 to 5,
000 polycaprolactone-based glycol or polyhexane adipate-based glycol, 4,4'-methylene bis(cyclohexyl isocyanate), and 4,4'-methylene bis as a bifunctional active hydrogen compound. An improved suede-like artificial leather characterized by being made of polyurethane formed by reaction with (cyclohexylamine) as a main component.