JPS60141735A - Manufacture of sheet with good crease pattern - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a sheet material with excellent creases by wet-coagulating a solution of a polymer mainly composed of polyurethane distomer.

Conventionally, sheet products have been provided with a coating layer made of a polymer mainly composed of polyurethane elastomer on a fibrous base material such as a nonwoven fabric, woven fabric, or knitted fabric, or a base material impregnated with a binder resin. Because its appearance and physical properties are similar to natural leather, it is widely used as a substitute for natural leather in shoes, bags, balls, belts, clothing, etc. Naturally, these sheet products are required to have a smooth surface similar to that of natural leather, as well as excellent properties such as texture, creases, and bending resistance. When used by hand or bent, natural and moderately sized creases and grains occur just like natural leather, giving it a soft appearance and a sense of luxury. extremely important. Such required quality can be achieved by forming the interior of the sheet material, which is made of a polymer mainly composed of polyurethane elastomer, into a uniform sponge structure.

A sponge structure can be obtained by wet coagulating a solution of a polymer mainly composed of polyurethane elastomer, but it is not easy to obtain a uniform sponge structure. In particular, it is more difficult to convert ether-based polyurethane elastomers that use polyether glycol as a soft segment component or ether-ester-based polyurethane elastomers that use polyether glycol and polyester glycol to ester-based polyurethane discs that use only polyester glycol. be.

The reason for this is that ether-based or ether-ester-based polyurethanes are highly hydrophobic, and during wet coagulation, a strong film (
This is because a skin layer) is formed which inhibits the exchange of the non-solvent in the coagulation bath and the solvent in the polymer solution. Conventionally, methods to improve this 3- disadvantage include adding higher alcohols, higher fatty acids, urethane, ureide, polyethylene glycol, boric acid, water, etc. to the polyurethane distoner solution, and adding the polyurethane solution to a coagulation bath. A method has been proposed in which, prior to immersion, the solution is allowed to stand in air containing a large amount of water vapor or moisture to partially gel. However, these methods are not necessarily sufficient for obtaining a uniform sponge structure, and from a manufacturing standpoint, it is difficult to prepare the polyurethane disstomer solution, or the wet coagulation process is difficult. The process is complicated, and the permissible range of the conditions is narrow, making it difficult to control.

As a result of extensive research in order to solve this problem, the present inventors have found that alkyl phosphates, ethylene oxide adducts of alkyl phosphates, aralkyl phosphates, and At least one compound selected from the group consisting of phosphates and ethylene oxide adducts of aralkyl phosphates is added, and the solution is wet-coagulated under coagulation conditions such that a giant sponge is generated. It has been found that a uniform sponge structure can be easily and stably obtained, and as a result, a sheet product with excellent folding texture can be manufactured.

Next, each component of the present invention will be explained in detail. In the present invention, the polymer solution to be wet-coagulated may be impregnated or coated on a fibrous base material, or coated on a support. It may be in a state where The fibrous base material is a sheet-like material mainly composed of fibers such as nonwoven fabric, woven fabric, or knitted fabric, which is optionally impregnated and coagulated with a fiber polymer as a binder. The fibers that make up the fibrous base material include cotton, hemp, wool, rayon, acetate, nylon, polyester, polyacrylonitrile, vinylon, polyolefin, etc. In the case of synthetic fibers, of course, single spun fibers are used. , a mixture of these or these with other polymers, or a composite spun fiber. When mixed or composite spun fibers are used, a method of extracting and removing at least one polymer from a plurality of polymers constituting the fibers or dividing the polymers at any stage of producing a leather-like sheet. It is preferable to adopt

As the binder optionally added to the fibrous base material, generally all those used for leather-like sheet products can be used, such as polyurethane elastomer, polyvinyl chloride, natural rubber, synthetic rubber, etc. be done. These binders are impregnated in a solution or emulsion state into a sheet material mainly made of fibers by an impregnation method, a coating method, etc., and are coagulated by a dry method or a wet method. It is preferable to have a structure having the following from the viewpoint of texture, tear strength, etc. When a polymer mainly composed of polyurethane elastomer is used as the binder resin, the method of the present invention can also be used as a method for applying this resin. A non-porous coating layer is applied. If the method of the present invention is not applied to the base layer, it is applied to this coating layer. In this case, the covering layer is naturally porous or a laminate of it and a non-porous layer. The porous coating layer can be applied by applying the polymer solution directly onto the substrate and wet-coagulating it, or
Alternatively, it can be integrated with a fibrous base material by coating it on a support, wet-coagulating it, and then pasting the resulting porous film onto the base material.

The polyurethane distomers used in the present invention are synthesized from polymeric glycols, organic polyisocyanates, and chain extenders. Polymer glycols include polyester glycols such as polyethylene adipate glycol, polybutylene adipate glycol, polyhexamethylene adipate glycol, and polycabrolactone glycol; polyester glycols such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and polyhexamethylene glycol; Examples include ether 7-glycols and the like. Examples of the organic polyisocyanate include tolylene diisocyanate, diphenyl diisocyanate, diphenylmethane-4,4'-diisocyanate, naphthylene diisocyanate, xylylene diisocyanate, dicyclohexylmethane-4,4'-
Examples include diisocyanate, dicyclohexyl diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, and the like. In addition, as chain extenders, low molecular weight compounds having one or more active hydrogen atoms, such as ethylene glycol, propylene glycol, phethylene gelylcol, pentyl glycol, hexyl glycol,
Diethylene glycol, 4,4'-dihydroxydiphenylmethane, hydrazine, ethylene diamine, trimethylene diamine/, propylene cyabane, butylene diamine, pentyl diamine, hexamethylene diamine, N-methyltrinothi tzy diami 7.F:I-:V7 diami 7
・Tono''') diamine, naphthylenediamine, 4.4'
-diaminodiphenylmethane, dicyclohexyldiamine, 8-4,4'-diaminodicyclohexylmethane, isophoronediamine, ethanolamine, butanolamine, hexanolamine and the like. In particular, when polyether glycol having an alkylene group having 2 to 6 carbon atoms is used as the soft segment component, or a polyester glycol which is a condensation product of a glycol having 2 to 6 carbon atoms and adipic acid is used. It is preferable to use them together in terms of coagulation properties and physical properties, and the average molecular cap is 5.
A range of 00 to 4,000 is preferred. Further, as the organic polyisocyanate, one having an aromatic ring, particularly diphenylmethane-4,4'-diisocyanate, and as the chain extender, alkylene glycol having 2 to 6 carbon atoms is best in terms of coagulability and physical properties. Furthermore, from the viewpoint of coagulation properties and physical properties, the nitrogen content based on incyanate groups in the polyurethane elastomer is 2.5 to 7 times i.
t%, especially 4 to 6% by weight of polyurethane elastomer is preferred.

The polyurethane elastomer may contain polymers with good compatibility in solution, such as polyvinyl chloride, polyvinyl acetate, polyvinyl formal, methacrylic acid resin, vinylidene chloride-acrylonitrile copolymer, and vinyl chloride-vinyl acetate copolymer. In addition to polymers, various stabilizers,
Fillers, pigments, dyes, etc. may be added as necessary.

In addition, in the solution of the polymer mainly composed of the polyurethane distomer, an alkyl phosphate, which is a feature of the present invention, is added in order to improve wet coagulation properties and obtain a uniform sponge structure.
At least 119m of a compound selected from the group consisting of ethylene oxide adducts of alkyl phosphates, aralkyl phosphates, and ethylene oxide adducts of aralkyl phosphates is added. These compounds form extremely uniform giant pores in the polymer layer, and are extremely effective in improving the texture, texture, bending resistance, air permeability, and moisture permeability of the resulting porous layer. Demonstrate the effect of

Although K has the great advantage of being particularly resistant to bacteria, hydrolysis, and chemical deterioration, it has not been widely used until now due to its poor wet coagulation properties. It is truly surprising that the compounds are also very effective against polyurethane elastomers based on polyurethane or ether-based esters.

Examples of alkyl phosphates include potassium octyl phosphate, potassium decyl phosphate, potassium oleyl phosphate, potassium lauryl phosphate, potassium stearyl phosphate, sodium octyl phosphate, sodium oleyl phosphate, sodium lauryl phosphate, and sodium stearyl phosphate. Can be mentioned. In addition, among aralkyl phosphates and l-, there are potassium nonylphenol phosphate, potassium tesylphenol phosphate, potassium oleylphenol phosphate, potassium stearylphenol phosphate, sodium nonylphenol phosphate, sodium laurylphenol phosphate, etc. Ethylene oxide adducts are also very useful. The amount of these compounds to be used is preferably 1% by weight or more and 50% by weight or less based on the weight of the polymer.

Furthermore, when at least one compound selected from the group consisting of water, fatty acid ester, alkyl diamine acetate, and titanium oxide is used in combination with these compounds, a porous sheet material with even better texture can be obtained.

As fatty acid esters, capric acid methyl ester,
Examples include lauric acid methyl ester, stearic acid methyl ester, stearic acid ethyl ester, stearic acid butyl ester, etc., and examples of alkylene diamine acetate include ethylenediamine sodium acetate, ethylenediamine acetate, ethylenediamine sodium acetate, etc. The amount of each of these added is 0.1 to 10% relative to the polymer.
Weight percent is preferred. When using hot water, the preferable addition amount is 1 to 40% by weight based on the polymer solution, and when using titanium oxide, it is 0.1 to 10% by weight based on the polymer solution.
Weight%.

In the method of the present invention, such a compound is added and a solution of a polymer mainly composed of polyurethane elastomer is wet-coagulated. An organic polar bath medium or a mixed solvent in which other solvents such as alcohols and cellosolves are added thereto is generally used.

Wet coagulation of a solution of a polymer mainly composed of polyurethane elastomer involves immersing the solution of a polymer mainly composed of polyurethane elastomer in a coagulation bath containing a non-solvent of the polymer or a mixture of this and a solvent. This is done by In the present invention, the solidification conditions must be such that giant pores are generated. Incidentally, the term "giant pores" as used in the present invention means pores having a maximum diameter of 50 μm or more, and the maximum diameter can be measured from a cross-sectional photograph of the sponge structure. In general, the diameter of the pores can be freely changed depending on the temperature of the coagulation bath, the ratio of non-solvent in the coagulation bath, the concentration in the polymer solution, the type and amount of the compound added, etc. These conditions must be set so that pores are generated. As a general trend, the lower the temperature of the coagulation bath, the higher the proportion of non-solvent in the coagulation bath, and the lower the concentration of polymer in the polymer solution, the larger the diameter of the pores. 13- Ru. If giant pores are not generated due to the wet coagulation conditions or the amount of the compound added, a porous layer with good creases cannot be obtained, as described above.

The present invention will be specifically described below with reference to Examples.

It should be noted that all values in the examples are based on weight.

Example 1 Polytetramethylene glycol/polyethylene adipate glycol (weight ratio 3/2) and diphenylmethane-4,4' were placed on a polyethylene film as a support.
- Polyurethane elastomer 16 with a nitrogen content of 4.8% synthesized from diisocyanate and ethylene glycol
0.3% of titanium oxide, 1% of potassium polyoxyethylene nonylphenol phosphate, and 8% of dimethylformamide
A 2.7% solution was applied at a solid content of 80 r/m”,
3 in an aqueous solution at 43°C containing 41 dimethylformamide.
After being immersed for 0 minutes to solidify, it was peeled off from the support, thoroughly washed with water to remove the solvent, and then dried. This product had uniformly formed giant sponges with a maximum diameter of about 500 μm inside 14- and had good surface smoothness. This was then adhered onto a polyester woven fabric using a cross-linked polyurethane elastomer solution, and on top of this was an 8% polyurethane elastomer consisting of polyethylene adipate glycol, diphenylmethane-4,4'-diisocyanate and 1,4-butanediol, oxidized. A solution consisting of 8% titanium, 36% dimethylformamide, 28% acetone, and 18% cyclohexanone was applied using the gravure method to a solid content of 3.5μ, dried, and then embossed with a kid pattern. A rubbing process was performed.

The leather-like sheet material [1] obtained in this manner had good appearance, texture, bending resistance, etc. as well as wrinkles.

Meanwhile, on the same support as above, 12% of the same polyurethane distomer, 0.3% of titanium oxide, 0.3% of stearyl alcohol, and 87% of dimethylformamide were added.
．． A porous film was obtained by applying a 4% solution in the same manner as above, followed by wet coagulation, solvent removal and drying in the same manner as above.

The inside of this thing was dotted with huge, uneven sponges, and the surface was extremely uneven. This was adhered to a polyester woven fabric in the same manner as above, and then a finishing layer of polyurethane nidistomer was applied, and a kit pattern was embossed and rubbed in the same manner as above to produce a leather-like sheet material (II). This product did not have a sufficient kid pattern and had a very poor appearance. In addition, the creases were extremely poor and the product value was low.

Example 2 On a nylon nonwoven fabric, 12% polyurethane elastomer with a nitrogen content of 4.3% synthesized from polycaprolactone glycol, diphenylmethane-4,4'-diisocyanate and ethylene glycol, 1% polyvinyl chloride,
Carbon black 0.1%, sodium lauryl phosphate 0.
5% water 0.5% and water 7°”85.9
“″″″, ffi? Li1l.

Then, the same solution was applied on top of this at a solid content of 10 (1/m), immersed in an aqueous solution containing 42% dimethylformamide at 46°C for 30 minutes, and after wet coagulation, the solvent was thoroughly removed. It was dried. This polymer layer had uniform giant pores with a maximum diameter of about 500 μm, and the optical surface had good smoothness. Furthermore, on top of this, the same polyurethane elastomer as the finishing layer in Example] was applied. 8%, carbon black 0.
A solution consisting of 3% dimethylformamide, 36% acetone, and 19.7% cyclohexanone was applied to a solids thickness of 3μ, dried, embossed with a coarse grub pattern, and then rubbed. is missing. The thus obtained leather-like sheet] had good folding texture, appearance, texture, physical properties, etc., and had high commercial value.

Example 3 The same nylon nonwoven fabric as in Example 2 was coated with 16% of a polyurethane elastomer with a nitrogen content of 5.0% consisting of 1-polytetramethylene ether glycol, diphenylmethane-4,4'-diincyanate and 1,4-butanediol.
, carbon black 0.16%, titanium oxide 0.16%
, polyoxyethylene dodecyl 17-lephenol sodium phosphate 2%, methyl stearate 0
．． 1%, 0.1% sodium ethylenediaminetetraacetate, and 81.48% dimethylformamide.The same solution was applied to the rice bowl in an amount of 120t7m'' in terms of solid content, followed by wet coagulation, desolventization, drying and The finishing treatment was carried out in the same manner as in Example 2. This polymer layer also had uniform giant pores with a maximum diameter of 300 μm, and the folding, appearance, texture, physical properties, etc. were very good.

Examples 4 to 9 In the method of Example 1, polyoxyethylene nonylphenol potassium phosphate was added to the compound listed in ■ in Table 1 below,
A leather-like sheet material was produced in the same manner as in Example 1 except that titanium oxide was replaced with the compound described in (1). In addition, in these examples, the polyurethane distomer content in the solution was 16%, and the total amount was 100% by increasing or decreasing the amount of dimethylformamide in the solvent.
was maintained. Both of the obtained sheet products had excellent folding texture and excellent appearance, texture, and physical properties. However, ■18-

Claims (1)

[Claims] (1) Alkyl phosphates, ethylene oxide adducts of alkyl phosphates, aralkyl phosphates, and ethylene oxide adducts of aralkyl phosphates are added to a solution of a polymer mainly composed of polyurethane elastomer. 1. A method for producing a sheet material having good crease texture, characterized by adding at least one compound selected from the group consisting of: and wet-coagulating the solution under coagulation conditions such that a giant sponge is generated. (2) The manufacturing method according to claim 1, wherein the polyurethane nidistomer is an ether-based or ether/ester-based polyurethane nidistomer. (8) Claims in which at least one compound selected from the group consisting of water, fatty acid ester, alkyldiamine acetate, and titanium oxide is further added to a solution of a polymer mainly composed of polyurethane distoner. The manufacturing method according to item 1 or 2.