JPH0639751B2 - Method for producing sheet having unevenness pattern on surface layer of polyurethane resin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention has an uneven pattern on the surface layer of a polyurethane resin,
The present invention relates to a method for manufacturing a sheet in which the uneven pattern is color-enhanced. The sheet obtained by the method of the present invention is used for clothing parts, ornaments, folding names, marking design sheets, and the like.

[Conventional technology]

A sheet in which a surface layer made of a polymer such as polyurethane resin is provided on a substrate made of fibers such as a woven or knitted fabric and a non-woven fabric is known as artificial leather or leather. It is also known to form a concavo-convex pattern on the surface layer of resin such as artificial leather or leather by hot pressing. Further, since the resin surface layer is colored by the porous layer, the color of the crushed part looks dark and a color pattern is generated together with the uneven pattern, or the resin surface layer is preliminarily subjected to the uneven pattern. It is also known that an uneven pattern and a color pattern are attached by coloring the colored pattern and then shaping the uneven pattern. A sheet having such an uneven pattern and a color pattern related thereto has
Compared with a sheet of uniform color having only an uneven pattern, the uneven pattern is emphasized by the colored pattern, and is noticeable. However, even in the case of a sheet having an uneven pattern and a color pattern, if the uneven pattern and the color pattern are unrelated,
On the contrary, the color pattern makes the uneven pattern inconspicuous.

[Problems to be Solved by the Invention]

A sheet having a concavo-convex pattern obtained by the conventional technique as described above and a color pattern related to the concavo-convex pattern has an artificial color pattern because the color tone, contour, etc. of the color pattern are determined in advance by coloring or heat pressing. There is a problem that it does not give a beautiful feeling, and it does not give a natural change.

The present invention is a sheet having a concavo-convex pattern and a color pattern that can change the color tone, contour, etc. of the color pattern related to the concavo-convex pattern after hot pressing, and that can make the color pattern have an aesthetic appearance that naturally changes. An object of the present invention is to provide a manufacturing method of.

[Means for Solving the Problems]

The present invention, on the surface of a sheet having a layer made of a polyurethane resin as a surface layer, is a polyurethane resin layer of one layer or two or more layers, and when the resin layer is a single layer, the surface layer is different in color, and the surface layer is a solvent. A polyurethane resin layer that is easily soluble in the other, on the other hand, when the resin layer is two or more layers, at least the uppermost layer and the next layer have different colors, and the uppermost layer is a two-layer polyurethane that is more soluble in the solvent than the next layer. After forming the resin layer, an uneven pattern is formed on the polyurethane resin layer by pressing from the surface of the one or two or more polyurethane resin layers, and then the sheet is dissolved, and the polyurethane resin layer on the outermost surface is dissolved. However, there is a method for producing a sheet having an uneven pattern on the surface layer of the polyurethane resin, which is characterized in that the polyurethane resin layer below is treated with a solvent that does not dissolve and remains. To achieve the above object by the configuration.

[Work]

That is, in the method of the present invention, the laminated polyurethane resin layer is subjected to a solvent treatment to dissolve the polyurethane resin layer on the surface after forming irregularities by pressing, so that the polyurethane resin layer on the surface is uniformly formed. As you said, the uncrushed, uncrushed convex part melts the fastest, then the central part of the concave surface that melts at the next faster speed melts, and the crushed side parts and corners melt the slowest, There is a difference in the dissolution rate at each part of the uneven pattern. Therefore, by stopping the solvent treatment before the polyurethane resin layer on the surface is completely dissolved, the color of the remaining polyurethane resin layer on the sheet and the polyurethane resin layer on the surface were dissolved in addition to the uneven pattern on the sheet. Then, a color pattern due to a different color of the next polyurethane resin layer appears. The color pattern, in association with the uneven pattern, emphasizes the uneven pattern to make it stand out, and also gives a aesthetic impression of showing a natural change. For example, when the color of the polyurethane resin layer on the laminated surface is black and the color of the polyurethane resin layer of the next layer is silver white, the solvent treatment causes the uneven pattern to be formed of silver, and the sliding portion has a silver color. A color pattern that gives an aesthetic impression that black rust remains on the non-rubbed portion occurs.

〔Example〕

The sheet having a layer made of a polyurethane resin used in the method of the present invention as a surface layer is, for example, impregnation, coating, combination of impregnation and coating, impregnation and film on a base material such as woven or knitted fabric or nonwoven fabric made of synthetic fiber or natural fiber. A sheet such as a known artificial leather or leather provided with a polyurethane resin layer having a porous structure by means of a combination of adhesion or the like may be used, or even if the surface polyurethane resin layer does not have a porous structure, or a substrate is used. A simple polyurethane resin sheet that is not used may be used. In the case of a sheet using a base material such as a woven or knitted fabric, since the base material enhances the elasticity of the sheet, the surface polyurethane resin layer may not be an elastic body having a porous structure. Is preferably an elastic body having a porous structure in order to form an uneven pattern. The porous polyurethane resin layer can be formed by a known wet coagulation method, dry foaming method, or the like.

When only one polyurethane resin layer is formed on the surface of the polyurethane resin layer of the sheet surface as described above, the polyurethane resin layer of the sheet surface layer is not dissolved by the subsequent solvent treatment but the polyurethane resin layer formed thereon is dissolved. Therefore, for example, the polyurethane resin for the surface layer of the sheet contains an aromatic diisocyanate such as methylene bis (p-phenylene isocyanate), p · p ′ phenylene diisocyanate, 1.5 naphthylene diisocyanate, and toluene diisocyanate. Polyalkylene ether diol, polyester diol, polylactodiol, polyalkylene carbonate diol, and other diols, and ethylene glycol, tetramethylene glycol, hexamethylene glycol, ethylenediamine, propylenediamine, hex Methylene diamine, 4, 4 '
Cyclohexyldiamine, 3,3.5-Trimethyl-5
Polyurethane resin obtained by reacting with a chain extender such as aminomethylcyclohexylamine, or a part of aromatic diisocyanate 4,4'-triphenylmethane triisocyanate, addition product of toluene diisocyanate and hexanetriol, Crosslinkable polyurethane resin with trifunctional triisocyanate such as adduct of hexamethylene diisocyanate and hexanetriol, or polyurethane resin obtained by partially mixing polyurethane resin using aliphatic or alicyclic isocyanate with these polyurethane resins , The resin of the polyurethane resin layer formed on the above, aliphatic diisocyanate such as tetramethylene diisocyanate, hexamethylene diisocyanate, cyclohexyl diisocyanate, 3,3,5 trimethyl, 5 isocyanate Over preparative and alone or mixed aliphatic diisocyanates such as methyl cyclohexyl isocyanate, polyalkylene diol, polyester diol,
A diol such as polylactone diol or polyalkylene carbonate diol, and a chain extender such as ethylene glycol, tetramethyl glycol, hexamethylene glycol, ethylenediamine, propylenediamine, hexamethylenediamine, 3,3.5 trimethyl 5 aminomethylcyclohexylamine, etc. A polyurethane resin obtained by the reaction may be used. Then, as the solvent for the solvent treatment, acetone, methylethylketone, methylisobutyleneketone, methanol, ethanol, isopropylalcohol, toluene, methylacetate, ethylacetate, etc. are used alone or as a mixture, or dimethylformamide, tetrahydrofuran is added to these solvents. , Dimethyl sulfoxide, etc. are used in a small amount within a range in which the polyurethane resin layer on the surface of the sheet is not so dissolved, the polyurethane resin layer on the formed surface is dissolved and the polyurethane resin layer on the sheet surface below is dissolved. It is possible to carry out a solvent treatment that does not dissolve.

Specific examples of the combination of the polyurethane resin and the solvent include, as the polyurethane resin for the sheet surface layer, methylene bis (p-phenylene isocyanate), polyethylene adipate having a molecular weight of 2,000 and a terminal diol, and ethylene glycol in a weight ratio of 1,000. : 2,0
Using polyurethane resin polymerized from 00: 186,
From the weight ratio of 666: 2,000: 180 of polyoxytetramethylene glycol having 33.5-trimethyl / 5-isocyanate methylcyclohexyl isocyanate and polyoxytetramethylene glycol having a terminal diol having a molecular weight of 2,000 and tetramethylene glycol as the uppermost polyurethane resin. An example can be given in which a polymerized polyurethane resin is used and a mixed solvent of toluene and isopropyl alcohol in a weight ratio of 50:50 is used as a solvent. As a further example, a polyurethane resin for the surface layer of the sheet was polymerized from a weight ratio of 735: 2,000: 225 of 1.5 naphthylene diisocyanate, polyoxytetramethylene glycol having a molecular weight of 2,000 and having a diol at the terminal, and ethylene glycol. Polyurethane resin, hexamethylene diisocyanate as the uppermost polyurethane resin and polybutylene adipate having a diol having a molecular weight of 2,000 at the terminal and tetramethylene glycol in a weight ratio 504:
For example, a polyurethane resin polymerized from 2,000: 180 may be used as a solvent using a mixed solvent of isopropyl alcohol, methyl ethyl ketone, and toluene 40: 4: 20.

The polyurethane resin layer is further formed on the polyurethane resin layer by applying a solution of the polyurethane resin directly by a method such as a roll coater, a gravure roll, a knife coater, or a spray, after applying it to release paper to form a film. It can be carried out by a known method such as bonding or extruding a hot-melt polyurethane resin from a die to form a film.

When only one polyurethane resin layer is formed on the surface of the polyurethane resin layer on the surface of the sheet, the color of the polyurethane resin layer on the surface of the sheet and the polyurethane resin layer on it are different, but only one of them is colored with a dye or pigment. Or by coloring both with different colors. In order to obtain a color pattern having an excellent effect, it is preferable to set the color difference ΔE of different colors to 1 or more. It goes without saying that an antioxidant, a light stabilizer and the like can be added to the polyurethane resin layer.

When two or more polyurethane resin layers are formed on the sheet surface polyurethane resin layer, the polyurethane resin layer and the sheet surface layer formed when only the uppermost polyurethane resin layer and the next polyurethane resin layer are formed The polyurethane resin layer does not have to be exposed to the surface, so that the solubility of the color and the solvent due to the solvent need not be regulated. That is, the same polyurethane resin as in the case of forming only one layer is used as the resin of the uppermost polyurethane resin layer, and the same polyurethane resin as the polyurethane resin of the sheet surface layer is used as the resin of the next polyurethane resin layer. The resin of the polyurethane resin layer below that may be the same as or different from any of the polyurethane resins described above. As for the color, if the uppermost layer and the next layer are different, the layers below it may or may not be colored. However, when the next layer is not colored, the color of the lower layer can be seen through the next layer when the uppermost layer is dissolved. Different colors are preferred.

The uneven pattern is formed on the polyurethane resin layer formed by laminating as described above by heating and pressing the lamination of the polyurethane resin layer with a heated mold, embossing roll, high frequency electrode mold, ultrasonic horn, or the like. The method is, for example, a method of heating the laminated polyurethane resin layer and pressing it with a mold, a resin mold or an embossing roll. It is preferable that this shaping imparts a height difference of unevenness equal to or more than the thickness of the polyurethane resin layer on the surface so that the uneven pattern is surely left after the solvent treatment.

The solvent treatment after forming the uneven pattern is carried out by using a solvent as described above which dissolves the polyurethane resin layer on the surface but does not dissolve the polyurethane resin layer thereunder. This solvent treatment is preferably stopped when the polyurethane resin layer on the surface is still appropriately left. As a result, as described above, a color pattern exhibiting a natural change is caused by the color of the remaining surface polyurethane resin layer and the color of the polyurethane resin layer below. In the case where the purpose is to change the color of the sheet from that which is not subjected to solvent treatment, the polyurethane resin layer on the surface may be completely dissolved.

With regard to the production method of the present invention described above, more specific examples will be given. As a sheet having a layer made of a polyurethane resin as a surface layer, methylene bis (p-phenylene isocyanate) and polyethylene adipate having an average molecular weight of 2,000 are used. And a 10 wt% dimethylformamide solution of a brown pigmented polyurethane resin having a nitrogen content of 4.2 wt% obtained by reacting ethylene glycol (chain extender) with a thickness of 1.0 mm composed of polyester fibers. Using a sheet obtained by impregnating the non-woven fabric, the surface of this sheet is coated with a 20 wt% dimethylformamide solution of the same polyurethane resin, and the surface of the artificial leather base obtained is coated with hexamethylene diisocyanate and isophorone diisocyanate. Mixture of average molecular weight of 2,000 Polytetramethylene glycol,
An 8 wt% isopropyl alcohol: toluene (50:50) solution of a beige pigmented polyurethane resin having a Chisso content of 3.5 wt% obtained by reacting hexamethylenediamine was applied by a gravure roll, After drying to form a beige polyurethane resin layer,
A lizard-like uneven pattern was formed on this surface with a heating embossing roll at 170 ° C, and the surface was wrapped with a cotton cloth impregnated with a mixed solvent of isopropyl alcohol: toluene (50:50). / Min) to produce an artificial leather having an uneven pattern. In the obtained artificial leather, a part of the convex parts and concave parts of the lizard pattern on the surface changes from beige to the brown color of the lower layer which remains undissolved by dissolving and removing the polyurethane resin layer on the outermost surface. , With a natural, uneven appearance.

〔The invention's effect〕

According to the method of the present invention, it is possible to obtain a sheet having an uneven pattern and a colored pattern which are emphasized by a colored pattern from the uneven pattern and which give an aesthetic impression that the colored pattern shows a natural change, and the same uneven pattern is obtained. It is also possible to easily obtain sheets of different colors.

Claims (1)

[Claims] 1. A surface of a sheet having a layer composed of a polyurethane resin as a surface layer, wherein one or more polyurethane resin layers are provided. When the number of the resin layers is one, the surface layer is different in color from the surface layer. A polyurethane resin layer which is easily soluble in a solvent, on the other hand, when the resin layer is two or more layers, at least the uppermost layer and the next layer are different in color, and the uppermost layer is a two layer which is more easily soluble in the solvent than the next layer. After forming the polyurethane resin layer, a concave-convex pattern is formed on the polyurethane resin layer by pressing from the surface of the polyurethane resin layer of one layer or two or more layers, and then the sheet, the polyurethane resin layer of the outermost surface is A method for producing a sheet having a concavo-convex pattern on the surface layer of a polyurethane resin, which comprises treating with a solvent that dissolves but leaves the underlying polyurethane resin layer undissolved.