JPS581733A - Production of sheet material having stable sponge structure - Google Patents

Abstract

PURPOSE:To produce the titled sheet material which has good sponge structure and is stable in a dried state, by coagulating polyurethane obtd. by using a mixed polymer glycol of a polyalkylene ether glycol and a polyester glycol. CONSTITUTION:A mixed polymer glycol consisting of 95-10wt% polyalkylene ether glycol having an average MW of 500-4,000 and 3-6C alkylene moiety and 5-90wt% polyester glycol having an average MW of 800-3,000, is used. Said mixed polymer glycol, an org. polyisocyanate and a chain extender are reacted together in such a proportion as to give an isocyanate-N content of 2.5- 7wt% to obtain a polyurethane soln. having a relative viscosity of 0.9 or above at 30 deg.C. 5-50pts.wt. additive such as a fatty acid ester of sorbitol having an HLB of 8-16 is added to 100pts.wt. (on a solid basis) said polyurethane soln. The mixed soln. is cast on a base sheet, and immersed into a coagulating bath contg. 20-70wt% solvent for polyurethane at 30-75 deg.C to coagulate the cast sheet which is then washed while leaving at least 10ppm said additive intact, and then dried.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing polyurethane sheet materials of stable sponge structure.

Conventionally, in the coagulation method in which a polyurethane solution is immersed in a non-solvent or solvent-non-solvent coagulation bath to form a sponge structure, the method for obtaining a stable sponge structure is as follows:
For example, water is added to the polyurethane solution. Methods using many additives such as higher alcohols, higher carboxylic acids or esters thereof, fatty acid esters of sorbitan or sorbitol, and higher hydrocarbons have been proposed. Furthermore, it has been proposed to make polyurethane using a polymer glycol that is a mixture of polyether glycol and preester glycol and coagulate it into a sponge structure in a coagulation bath (Japanese Patent Publication No. 25269/1983). However, in the case of polyurethane made using polymer glycols such as polyether glycol or polyester glycol alone, the previously proposed method is effective, but unlike polyether glycol and polyester glycol, it is difficult to use non-solvents, especially water. If components with significantly different compatibility are present in one &Q urethane molecule,
Their solidification behavior is different, and the range of conditions for promoting uniform solidification is extremely limited, making it difficult to implement industrially.

Furthermore, the polyurethane layer with a spongy structure obtained by coagulation has different drying points, and the spongy structure cannot be maintained stably, and the fine sponge is destroyed in small parts, causing unevenness on the surface and a yuzu skin-like surface. , and a good reward finish will not be able to obtain a surface. However, when polyurethane is used as the layer of artificial leather, it has 1.Oelastic behavior such as resilience, setting properties, and abrasion resistance.

Due to the usage characteristics of artificial leather such as hydroshock resistance 9 wearability,
It is preferable to use a mixed polyol as the polyurethane.Therefore, a polyurethane sheet material with a spongy structure that has a good ability to form an O-sponge structure when hardened and is stable even when drying is produced using a polyurethane using a mixed preol. A method for obtaining this is highly desired in the artificial leather industry.

The object of the present invention is to provide a method for obtaining a sheet material having a sponge structure that has a good O-sponge structure upon coagulation and is stable even when dried, from polyurethane obtained using a mixed polymer glycol of polyether glycol and l-lyester glycol. It is in.

The method of the present invention uses a prealkylene ether glycol which is an alkylene having an average molecular weight of SOO to 4 (160 and a carbon number of 3 to 6) and a prealkylene ether glycol having an average molecular weight of SOO to 4 (160) and an average molecular weight of
What is the weight ratio of preester glycol? 5 to 5 to 1
30 obtained by reacting Kajikai remer glycol, organic polyisocyanate and chain extender mixed in a ratio of 0:900 in a composition with a monomer content of 2.5 to 7% by weight based on isocyanate groups. The relative viscosity at °C is at least O,? 04! As an additive (
a) Fatty acid ester or ethylene oxide adduct of sorbitol or sorbitan with KL B 8 to 14; (b) at least one selected from l-lyoxyethylene alkyl, enyl ether or polyoxyethylene alkyl ether with HLB 2 to 10; Additive 5 to 50% of one type per 100 parts by weight of polyurethane
Parts by weight, preferably 10 to 40 parts by weight of the composition liquid are added to form a coating layer of a constant thickness, and the coagulation bath contains 20 to 70% by weight of polyurethane solvent and is at a temperature of 50 to 75°C. A process for producing a stable sponge-structured O-sheet material, characterized in that it is soaked, coagulated, washed, and dried with at least a portion of the additive remaining, preferably at least 10 ppm relative to the polyurethane overlay.

Examples of the polyalkylene ether glycol which is an alkylene having 3 to 6 carbon atoms and an average molecular weight of 500 to 4000 include pripropylene ether glycol, polytetramethylene ether glycol, and polypentamethylene ether glycol.

Direct reaction such as hexamethylene ether glycol
Real kylene ether glycols or side chain polyalkylene ether glycols are used. In the present invention, it is also preferred to use a mixture of at least 2 Mf) rR-polyalkylene ether glycols which are the same polyalkylene ether glycols as the polyalkylene ether glycols but differ in average molecular weight by at least 10 G.

Examples of the preester glycol having an average molecular weight of 800 to 3000 include adipic acid.

At least 1m dicarboxylic acid such as 11m group dicarboxylic acid such as sebacin, or aromatic dicarboxylic acid such as terephthalic acid, isophthalic acid, and at least 11m group dicarboxylic acid such as ethylene glycol, propylene glycol, butylene gellicol, hexamethylene glycol, etc. Polyester glycols obtained by polycondensation with glycol, such as polyethylene adipate glycol, glycethylene propylene adipate glycol, pributylene adipate glycol, lyhexamethylene adipate glycol, polyhexamethylene ethylene chloride glycol, polydiethylene ether Examples include terephthalate glycol, and I-relactone glycol obtained by #ring polymerization of Jj lactone, such as polycaprolactone glycol.

-tL, and in the present invention, the weight ratio of polyalkylene ether glycol and preester glycol is 95:5 to 10:? 00 ratio, preferably 80:20 l,
A ratio of 25:750 is preferable in terms of sponge O stability and elasticity such as resilience.

Examples of the cell organic isocyanate reacted with Yakura I remer glycol include tolylene diisocyanate, diphenyl diisocyanate), and 4,4'-di7enylmethane diisocyanate.

Naphthylene diisocyanate, icidal diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, dicyclohexyl diisocyanate. Examples include hexamethylene diisocyanate.

Examples of chain extenders include ethylene glycol, propylene glycol, butylene gelicol, pentyl glycol, hexyl glycol, diethylene glycol, 4,4'-dihydroxydiphenylmethane, etc.
Glycols, and ethylene diamine, trimethylene diamine, propylene diamine, butylene diamine, pentyl diamine, hexamethylene diamine, N-methyl tri-methylene diamine, phenylene diamine, tolylene diamine, 7-ethylene diamine a, 4/-diaminodiphenylmethane, dicyclohexylamine a
, al-diaminodicyclohexylmethane and other diamines.

The preurethane used in the present invention has at least 81
0 polymer glycol, at least 1 organic polyisocyanate and at least one chain extender, the amount of nitrogen based on the isocyanate groups (hereinafter referred to as nitrogen amount) is equal to the weight of the total composition, i.e., polymer guacol, organic The molecular weight of the polymer glycol and the composition of the polymer glycol, organic polyisocyanate, and chain extender are determined and reacted so that the amount is 2.5 to 7% by weight based on the total weight of the diisocyanate and the chain extender. If the amount of nitrogen is less than this range, the resulting sheet material will become too soft, the elasticity will be too high, or the stability of the sponge will be impaired, while if the amount of nitrogen is more than this range, the stability of the sponge will be good, but 1) It is not preferable to obtain the desired sheet material having a low elasticity.

Next, the urethane obtained by the reaction was dissolved in dimethylformamide (hereinafter referred to as DMF) solvent and heated to 50°C.
The reaction is allowed to proceed until the relative viscosity of the solution becomes 0.9 or higher. and the relative viscosity of the solution is from 0.9 to about 2
．． Set it to O in the 50 range before use. ζ01111 can also be used as a sponge structure or as a preurethane. Although there is no change in general performance, at least 0.
On the other hand, if the relative viscosity is about 2.5 or more, the coating processability will deteriorate, so the upper limit of about 2.5 is a viscosity determined from workability, but if the polyurethane concentration of the solution is low. The viscosity of this solution may be high.

Used as an additive in the polyurethane solution of the present invention (
a) Fatty acid esters or ethylene oxide adducts of sorbitol or sorbitan with an HLB of 8 to 16 include, for example, carboxylic acids having 10 to 30 carbon atoms. Preferably 16 to 2°, such as capric acid, lauric acid, myristic acid, palmitic acid,
mono-, di-, or tri-carboxylic acid esters in which stearic acid or araxic acid is condensed with sorbitol or sorbitan, or carboxylic acid esters of polyoxyethylene sorbitan in which 5 to 30 moles of ethylene oxide are added to the carboxylic acid esters of sorbitol or sorbitan; For example, preoxyethylene sorbitan monostearate, polyoxyethylene sorbitan monooleate, polyoxyethylene sorbitan monopal t5-
1, l oxyshetylene sorbitan distearate,
and carboxylic acid esters of polyoxyethylene sorbitol, such as l-lyoxyethylene sorbitol monostearate and polyoxyethylene sorbitol distearate. (b) The preoxyethylene alkyl phenyl ether or polyoxyethylene alkyl ether with HLB 2 to 10 has 6 carbon atoms and has 2 to 50 moles of ethylene oxide added thereto.
to 18 furkyl 7-enyl ethers and alkyl ethers such as f-lyoxyethylene nonylphenyl ether and l-lyoxyethylene octylphenyl ether. Carry at least 1 liter of these additives and add it to 100 parts by weight of polyurethane M5 to 50 parts by weight, preferably 10 to 4 parts by weight.
A polyurethane composition liquid containing 0 parts by weight was prepared. This OI
The sponge is sufficiently stabilized with a small amount of addition! If Il drops are not obtained and are removed by washing after /II urethane coagulation, there is no problem in cases where there are a lot of problems, but it is just a waste.

This additive has a great stabilizing effect when it is present in the polyurethane during the formation of spofuji, and the polyurethane composition liquid also contains alcohols, water, hydrocarbon carboxylic acids, carboxylic acid esters, etc. as coagulation regulators. It is also preferable to use them together in order to adjust the sponge structure.

Then, the added additives can be dried while leaving at least a portion of them, preferably 10 ppm or more based on the weight of the preurethane, until the urethane solidifies and is first dried to stabilize the sponge structure. is necessary. If no additive remains, the sponge structure will be locally destroyed during drying, making it impossible to obtain a sheet material with a good polyurethane sponge structure with smooth deformed surfaces.

Also, to prevent unwanted sponge formation, 1
Nobori urethane composition liquid 01 of the present invention! II is.

Coagulation is carried out in a coagulation bath containing 20 to 70% by weight of a urethane solvent at a temperature of sO to 75°C. The polyurethane sheet material after coagulation is washed until the polyurethane solvent content is 5% or less, preferably 14% or less, or substantially eliminated, and then dried.

Hereinafter, the embodiments of the present invention will be specifically described with reference to Examples, but the present invention is not limited to these Examples. Note that the middle portions and percentages of Examples refer to overlapping unless otherwise specified.

Example 1 Polytetramethylene ether glycol 301i 1% with a molecular weight of 850, molecular weight 15 sD O/+1+)97 tyrene-ether glycol 301i%% and a molecular weight of 20
00 polyethylene propylene adipate glycol (
Ethylene: Propylene = 9 mol: 1 mol) 40 heavy ffi
%O mixed polymer glycol 465 parts.

446 parts of 4'-diphenylmethane diisocyanate and aa part of ethylene glycol were used to obtain a preurethane having a relative viscosity of 1.10 at 30 DEG C. (If elementary content: 5%).

14% of this preurethane, 1% of carbon black,
Proxyethylene nonylphenyl ether (LB-
5,7) A composition solution containing 5% $I J HiDMF 741% was prepared. The viscosity of this liquid composition was 35 poise at 50°C.

This polyurethane composition liquid was cast onto a glass plate to a thickness of 1.4 mm, and was solidified by immersing it in a coagulating solution of DMF504 aqueous solution at a temperature of 65°C. A fine, uniform sponge was formed in this plexus. The polyurethane film was peeled off from the glass plate, DMF was removed by washing with water, and the film was dried with hot air at 90°C. Note that the residual additive was as ppm.

The obtained film has a smooth surface and a uniform spongy structure of several microns, the thickness of the film is 0.57we, and the apparent honey density is 0.5? ~Met.

- 10,000, after thoroughly washing the preurethane film after coagulation and reducing the residual additives to a few ppm of 81 degrees,
The film dried with hot air at 0.degree. C. had fine irregularities on its surface, and the film was dense to a thickness of 0.52 m and an apparent density of 0.43 to 0.43.

In addition, for comparison, a polyurethane film obtained under the same conditions as the example without adding any additives to the polyurethane film had a thickness of 0.48 cm, an apparent density of about 0.47 rings, and slight irregularities were noticeable on the surface and was not smooth. was damaged.

Example 2 Polytetramethylene ether glycol with a molecular weight of 450 40% by weight 9 ? with a molecular weight of 1550? 40% by weight of ritetramethylene ether glycol and polyethylene propylene adipate glycol (ethylene:
Propylene = 9 mol: 1 mol) 4.6 parts of 20% by weight mixed primer glycol.

Using 429 parts of 44'-diphenylmethane diisocyanate and 75 parts of ethylene glycol, the amount of nitrogen was 4.8%.
, a polyurethane having a relative viscosity of 1.52 at 30° C. was obtained (preurethane B).

A composition of 22% polyurethane B, 75% DMF, 1.5% sorbitan monostearate, and 1.5% stearyl alcohol was prepared and impregnated into an entangled nonwoven fabric made of 2 denier nylon fibers, and then the surface 16% preurethane, 1% carbon black, #lyoxyethylene sorbitan tristearate (HLB 1)
0.5) 5% and DMF78% composition solution to a thickness of 0.
．． Cast coating on 8■, DMF 50% aqueous solution, temperature 60
It was coagulated by immersing it in a coagulation solution at ℃. Did you remove DMF by washing with water? The surface of the 5C hot air dried product was smooth and the sponge structure was not destroyed.

For comparison, a sheet material obtained by removing additives from the surface-coated polyurethane composition under the same conditions had a sponge structure that was partially destroyed during drying, resulting in slight irregularities on the surface, and a clean surface even after embossing. It didn't happen.

Further, the sheet material obtained in Comparative Example was dried in Example 2.
Polyoxyethylene sorbitan tristearate was dissolved in an alcohol-water solution, treated, and then dried, but the sponge structure was not sufficiently stabilized, and upon drying, the image became slightly uneven, which was not desirable. Ta.

Example 5 440 parts of a mixed primer glycol of 60% by weight of polytetramethylene ether glycol of molecule l 85 G and 40% by weight of polybutylene adiate gellicol of molecular weight 2000, 445 parts of 4,4'-diphenylmethane diisocyanate and 1.4- Using 115 parts of butanediol, a urethane with a nitrogen content of 5% was obtained (Polyurethane C
).

A sheet material was obtained under the same conditions except that this polyurethane C was replaced with the surface-coated polyurethane B of Example 201F. The O-sheet material had a uniform and stable spongy structure.

Example 4 Propylene ether glycol 6 with a molecular weight of 1200
Polycaprolactone glycol 40% by weight and molecular weight 2000 740 parts of mixed primer glycol in the weight form, 250 parts of 4,4'-diphenylmethane diisocyanate
Using 99 parts of 4.4'-diphenylmethanediamine and 99 parts of 4.4'-diphenylmethanediamine, a polyurethane with a nitrogen content of 2.5% and a relative viscosity of 1.26 was obtained.

This composition solution of 18% preurethane, 1% carbon black, 9% preoxyethylene (20 moles added) sorbitol, 9% tansotubalmitate, and 72% DMF was spread on a glass plate to a thickness of 1. Cast coating on Ova.

It was immersed in a 40% aqueous solution of DMF and coagulated at a temperature of 5 SC, washed with water to reduce the DMF content to 0.2% or less, and then dried with hot air at 90°C. Additives when drying are 1109p
It was p.

The resulting product had a uniform sponge and good durability.

Example 5 610 parts of a mixed polymer glycol of 40% polyhexamethylene ether glycol having a molecular weight of 1100 and 60% voccaprolactone glycol having a molecular weight of 1500,
A polyurethane having a nitrogen content of 2.7% was obtained using 262 parts of dicyclohexylmethane-4,4'-diisocyanate and 105 parts of dicyclohexylmethane-4,4'-diamine.

This preurethane is 15% and titanium oxide is 1.2%.

A composition solution of 10% polyoxyethylene (addition of 20 moles) sorbitan trioleate and 73.11% DMF was applied to an artificial leather substrate (a 1-inch thick substrate obtained by impregnating an entangled nonwoven fabric with nigari urethane and puffing the surface). . 0 thickness on the surface
．． 81 solution layer is formed, coagulated in a 50% DMF aqueous solution, washed with water, and dried with hot air at 105℃, the sponge has good stability (the surface is smooth, and the white-finished sheet material has good light resistance, It was a soft leather-like material with good hydrolysis resistance.

Patent applicant RiRashi Co., Ltd. Agent Benfumotora Ken

Claims (1)

[Scope of Claims] 1. Polyalkylene ether glycol, which is an alkylene having an average molecular weight of SOO to 4000 and a carbon number of 3 to 6, and a polyester glycol having an average molecular weight of 80 to 3000 in a ratio of 9s:5 to 10:90. It was obtained by reacting the mixed primer glycol, organic polyisocyanate and chain extender mixed in the opening in a composition in which the amount of nitrogen based on isocyanate groups was 2.5 to 7% by weight. (a) a fatty acid ester or ethylene oxide adduct of sorbitol or sorbitan with an HLB of 8 to 16;
A coating layer of a constant thickness is prepared by adding a composition liquid in which at least one selected from 2 to 10 polyoxyethylene alkyl phenyl ethers or polyoxyethylene alkyl ethers is added to 100 parts by weight of polyurethane and 5 to 50 parts by weight of an additive. The coagulation bath contains 20 to 70% polyurethane solvent, and the temperature is 30 to 7%.
A method for producing a stable sponge-structured sheet material, which comprises immersing the material in a liquid at 5° C. to solidify it, washing it, and drying it with at least a portion of the additive remaining. 2. The production method according to claim 1, wherein the polyalkylene ether glycol is at least one polymer glycol selected from polypropylene ether glycol, pritetramethylene ether glycol, and polyhexamethylene ether glycol. 5. The polyester glycol is a polyethylene adipate glycol, polyethylene propylene adipate glycol, polybutylene adipate glycol, prihexamethylene adipate glycol, and lactone. 1. At least one polymer glycol selected from the obtained polylactone glycol. A manufacturing method according to claim 1. 4. Claims in which the polyalkylene ether glycol is the same prealkylene ether glycol and a mixture of at least two identical polyalkylene ether glycols whose average molecular weights differ by at least 100 degrees! The manufacturing method according to item 1 or 2.