JPS5837051A - Stabilized polyurethane composition - Google Patents

Abstract

PURPOSE:To provide a polyurethane compsn. with improved resistance to hydrolysis and discoloration by gas, by adding a compd. with an oxazoline ring to a polyurethane. CONSTITUTION:A compd. having an oxazoline ring of the formula (where R is 1-30C alkyl) in the molecule is added to a polyurethane in an amount sufficient for its stabilization. The compd. is, e.g., a diol obtained by dehydration of an amidation product of tris(hydroxymethyl)aminomethane and a carboxylic acid or its anhydride or halide or a deriv. thereof. It is preferable that the diol is made to react with a (di)carboxylic acid and used as a (poly)urethane. A remarkable effect is obtained when the method is applied to a polyester polyurethane with a low stability to hydrolysis prepared by using mainly polyester or polylactone.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to stabilized polyurethane compositions. More specifically, it relates to polyurethane compositions with improved hydrolysis resistance, gas discoloration resistance, etc., especially polyester-based polyurethane compositions, from diisocyanates, relatively high molecular weight polymer diols, and low molecular weight polyfunctional active hydrogen compounds. The resulting polyurethane has excellent mechanical properties.

Foam and elastomer because they are easy to process.

Paint 1 Used in a wide range of applications such as synthetic leather and textiles. The characteristic elasticity of polyurethane elastomers is mainly due to relatively high molecular weight polymer diols.
Depending on whether the polymer diol is a polyether diol or a polyester diol, it is broadly classified into polyether polyurethanes and polyester polyurethanes. In general, polyester-based polyurethanes are characterized by higher elongation and superior elastic recovery properties than polyether-based polyurethanes.

Although it has many advantages such as excellent chlorine resistance, it has the disadvantage that it is susceptible to hydrolysis and deterioration when heated for a long time. It is also well known that not only polyester polyurethane but also polyurethane is easily discolored to yellow by nitrogen oxide gas or combustion gas of hydrocarbon fuel.

The present inventor has conducted extensive research to overcome these drawbacks of polyurethane, and as a result, has arrived at the present invention. That is,
The present invention is a stabilized polyurethane composition, characterized in that it contains a stabilizing amount of a compound having an oxazoline ring represented by formula (1) in the molecule.

(In the formula, R represents an alkyl group having 1 to 30 carbon atoms.) The polyurethane composition according to the present invention has significantly improved resistance to polyurethane hydrolysis, and can also greatly improve gas discoloration resistance. t7'? It is also a great advantage in industrialization that these properties can be improved without impairing the physical properties, moldability, etc. of polyurethane.

As the compound having an oxazoline ring in the molecule used in the present invention, tris(hydroxymethyl)aminomethane and carboxylic acid are prepared by dehydrating the amidation reaction product of tris(hydroxymethyl)aminomethane and carboxylic acid halide, or Examples include diols obtained by dehydrating esters of 2-alkyl-2-amino-1,3-propanediol and dicarboxylic acids, and derivatives thereof. This diol is usually reacted with a (di)carboxylic acid to form a (poly)ester,
It is preferable to use it as a (poly)urethane by reacting it with a (di)isocyanate or a (di)isocyanate. Also, the above (poly)
Esters can also be reacted with diisocyanates to form polyurethanes. The carboxylic acid used is
Acetic acid, propionic acid, lactic acid, butyric acid, dodecanoic acid, turic acid, balmitic acid, stearic acid, oxystearic acid, oleic acid, benzoic acid, dicarboxylic acids include adipic acid, sebacic acid, azelaic acid, terephthalic acid, etc. . In addition, as the isocyanate compound, phenylene isocyanate, hexamethylene diisocyanate, isophorone diisocyanate), 2.4-) lylene diiso Vane), 4.4'-dicyclohexylmethane diisocyanate, 4.4'-diphenylmethane diisocyanate t L4- Examples include s'chlorohexane diisocyanate. Among the above compounds, particularly preferred are K (poly)urethane compounds. A particularly preferred example is 4.4
It is a polyurethane with aliphatic diisocyanate such as '-dicyclohexylmethane diisocyanate and isophorone diisocyanate.

The polyurethane in the present invention has a hydroxyl group terminal and has a molecular weight of 600 to 7,000. Preferably 1000-60
00 polyester, polylactone.

Examples include polyurethanes obtained by reacting polyethers with diisocyanates, or by further chain extension with polyfunctional active hydrogen compounds, but polyesters and polylactones, which have particularly low hydrolytic stability, are mainly used. The effect is remarkable when applied to polyester polyurethane.

Polyesters used in polyester polyurethane include ethylene glycol, propylene glycol, 1,4
- glycols such as butanediol, 1,6-hexanediol, neopentyl glycol, V-chlorohexanediol - and succinic acid, adipic acid, superric acid, sebacic acid, azefinic acid, isophthalic acid 5L2-s'chlorohexanedicarboxylic acid Examples include those obtained by reaction with dicarboxylic acids such as, and those obtained from caprolactone. In addition, as a diisocyanate, 4.
4'-Diphenylmethane diisocyanate, 1゜4-phenylene diisocyanate% 2.4-) IJ diiso V anate, naphthalene diisocyanate, hexamethylene diisocyanate 5L4-s' Chlohexane diiso V anate, 4,4'-dicyclohexylmethane diisocyanate, xylene Examples include diisocyanate. Examples of polyfunctional active hydrogen compounds include hydrazine, ethylenediamine, 1,2-propylenediamine, hexamethylenediamine, xylylenediamine, 4
．． 4'-diaminodiphenylmethane, 4.4'-diphenylmethane disemicarpazide, ethylene glycol,
Examples include 1,4-butanediol and water.

In the present invention, the amount of the compound having an oxazoline ring in one molecule in the polyurethane is determined by the use of the polyurethane,
Although it varies depending on the form and the type of compound added, etc.1
Usually 0.05 to 10% by weight, preferably 0.1 to 10% by weight
5 weight.

The composition of the present invention may further contain known additives, such as antioxidants, ultraviolet absorbers, dyes and pigments, if desired.

A mold release agent etc. can be added.

Compounds can be blended into polyurethane to obtain the composition of the present invention at any stage of polyurethane production, but it is preferable to mix the compounds after polyurethane polymerization and before the molding stage. The polyurethane composition obtained in this way is dried.

Foams and elastomers that can be molded into fibers, tapes, films, etc. by blending or melt molding.

Although K can also be used for synthetic leather, paints, adhesives, etc., it is particularly useful for clothing fibers and tape applications.The present invention will be specifically explained below with reference to examples. It is not limited in scope.

In addition, 1j! Parts and parts in the examples indicate parts by weight and percentages by weight unless otherwise specified. Moreover, the monovalent value in Examples was carried out by the following method.

Hydrolysis Resistance Test Polyurethane fibers were immersed in boiling water at 80° C. for a fixed length, and changes in strength were measured untreated, after 3 days, and after 78 days.

(Using an Instron type tensile tester) A test was conducted according to JIS L-0855-1976K. Three units were tested, and the b values before and after the test were measured using a ND-101DP type color difference needle manufactured by Nippon Heavy Industries Co., Ltd., and the degree of discoloration was expressed by the change (jb).

Example 1 292 parts of adipic acid, 124 parts of ethylene glycol and 18 (l) of 1,4-butanediol were placed in a 1J flask and heated at 210°C for 2 hours under a nitrogen atmosphere at normal pressure. Then, 0. Add 0.02 parts and 0.025 g of triphenyl phosphite and gradually reduce the pressure at 210°C, reduce the pressure to 0.2 ■Hf in 2 hours, KL, 0.2
(2) The mixture was further heated for 2 hours under a pressure of If. Polymer 106f
A copoly(ethylene-butylene) adipate having a melting point of 32 DEG to 35 DEG C. and having 680 hydroxyl groups and 4.8 carboxy, syl groups per product was obtained. 100 parts of this copolyester and 4
．． After stirring 21.4 parts of 4'-diphenylmethane diisocyanate in an IJ polymerization flask, 80 parts of N,N-dimethylacetamide was added to form a homogeneous solution. Next, this solution was heated to 50° C. and reacted for 60 minutes to obtain an intermediate polymer. Then N,N-dimethylacetamide 22
After adding 0 parts to make a homogeneous solution, it was cooled with blO'ct,
A solution of 3.2 parts of 1,2-diaminopropane dissolved in 30 parts of N,N-dimethylacetamide was gradually added over 30 minutes to obtain a polyester polyurethane polymer solution.

On the other hand, 60 parts of tris(hydroxymethyl)aminomethane and 51 parts of acetic anhydride were reacted in 100 parts of acetic acid at room temperature, then acetic acid was distilled off, and the mixture was heated at 175° C. in a nitrogen stream until no water was distilled out.

58 parts of the obtained 2-methyl-4-dimethylol-l-oxatholine and 80 parts of 4,4'-dicyclohexylmethane diisocyanate were added to 138 parts of N,N-dimethylacetamide.
The mixture was reacted at 60'C for 30 minutes to obtain an oxazoline ring-containing polyurethane solution. This was added to the polyester/polyurethane polymer solution to give a concentration of 3.0% in terms of solid content, and dry-spun in a conventional manner to obtain a 55-denier polyurethane fiber.

The resulting nine fibers were tested for hydrolysis resistance and gas discoloration resistance, and the results are shown in Example 2. Table IK is shown together with the results of Comparative Examples 1 and 2. 60 parts of tris(hydroxymethyl)aminomethane and 142 parts of stearic acid were melted at 175°C.

The reaction was carried out with stirring in a nitrogen stream, and heating was continued until no more water was distilled out. Obtained 2-heptadecyl-
74 parts of 4-dimethylol-oxazoline and 39 parts of 4,4/-disyctetrahexylmethane diisocyanate were combined with N,
The mixture was reacted in 450 parts of N-dimethylacetamide at 70°C for 40 minutes to obtain an oxazoline ring-containing polyurethane solution. This was added to the polyester polyurethane polymer solution of Example 1 with a solid content of 4.0. Add Kl to give a concentration of %,
A polyurethane fiber of 55 denier was obtained by dry spinning using a conventional method.

Comparative Examples 1 and 2 When no additive is added to the polyester polyurethane=4 composite of Example 1 (Comparative Example 1), 1,3.5-tris(3,5-di-t-butyl-4-hydroquine) When 2% of benzyl)isoV anuric acid was added (Comparative Example 2)
Polyurethane fibers of 55 denier were obtained by dry spinning and tested for hydrolysis resistance and gas discoloration resistance as in Example 1.2. It can be understood that color change properties can be obtained.

Patent applicant: Toyobo Co., Ltd.

Claims (1)

[Scope of Claims] 1. A stabilized polyurethane composition characterized in that a stabilizing amount of a compound having an oxazoline ring represented by formula IJ) is blended into the molecule of polyurethane. 2. The stabilized polyurethane composition according to claim 1, wherein the polyurethane is a polyester polyurethane. 3. The stabilized polyurethane composition according to claim 1, wherein the compound having an oxazoline ring is a polyurethane having an oxazoline ring.