JPH0425307B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a stabilized polyurethane composition, and more particularly to a polyurethane composition stabilized against discoloration and deterioration due to outside air conditions or combustion gas, deterioration due to chlorine, and the like. In general, polyurethane products such as polyurethane elastic threads, foams, elastomer sheets, synthetic leather, and polyurethane resin-treated fiber products tend to discolor when exposed to an atmosphere of hydrocarbon combustion gas, nitrogen oxide gas, or outside air conditions for a long time. There are drawbacks. Furthermore, polyurethanes having urea bonds, urethane bonds, ether bonds, ester bonds, etc. in their molecules have drawbacks such as discoloration and deterioration even when exposed to light or heat. Normally, it is essential to add antioxidants and sometimes ultraviolet absorbers to polyurethane in order to stabilize it against light and heat, but these additives actually promote coloration due to combustion gas or nitrogen oxide gas. There is a tendency. Many proposals have been made for gas coloring inhibitors, but few have satisfactory performance, and even if they have excellent gas coloring resistance, they may impair other properties or lack durability. Very little is known that can be put to practical use. The present inventors took these problems into consideration and, as a result of intensive research aimed at improving the gas coloring resistance of polyurethane, arrived at the present invention. That is, the present invention is characterized in that a stabilizing amount of a tertiary nitrogen-containing urethane polymer terminal-capped with a sucrose fatty acid ester is blended into the polyurethane. The tertiary nitrogen-containing urethane polymer used in the present invention is, for example, a terminal isocyanate group-containing polyurethane consisting of a tertiary nitrogen-containing bifunctional compound, a tertiary nitrogen-containing diol, and an excess amount of an organic polyisocyanate. An example is a urethane polymer having a structure in which isocyanate groups are blocked by sucrose fatty acid esters. The tertiary nitrogen-containing diol to be used is not particularly limited, but the following are exemplified as preferred compounds. (However, in the general formulas (), (), (), R represents an alkyl group having 1 to 12 carbon atoms,
R ¹ may be the same or different alkyl groups having 1 to 4 carbon atoms, or two R ¹ and adjacent nitrogen atoms may form a heterocycle. ) (In the general formula (), R ² , R ³ , R ⁴ ,
R ⁵ and R ⁶ represent hydrogen or the same or different alkyl groups having 1 to 4 carbon atoms. ) (In the general formula (), R ⁷ may be an alkyl group having 1 to 4 carbon atoms, or two R ^7s and adjacent nitrogen atoms may form a 5- to 6-membered ring. It may contain oxygen or nitrogen. R ³ represents an alkyl group having 1 to 4 carbon atoms, and R ⁹ represents hydrogen or the same or different alkyl group having 1 to 4 carbon atoms.) Organic polyisocyanates may also be used. Although not particularly limited, aromatic diisocyanates such as 4,4'-diphenylmethane diisocyanate, 1,4-phenylene diisocyanate, 2,4-tolylene diisocyanate, naphthalene diisocyanate, 1,4-cyclohexane Diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, isophorone diisocyanate, ethylene diisocyanate, trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, 3,
Examples include aliphatic diisocyanates such as 3'-dimethylpentane diisocyanate. Among these, aliphatic diisocyanates are preferred. The sucrose fatty acid ester used for terminal blocking of tertiary nitrogen-containing urethane polymers is a compound in which 1 to 3 molecules of fatty acid are bonded to each molecule of sucrose through an ester bond, and examples thereof include compounds represented by the general formula (). . (However, in the formula, R ¹⁰ , R ¹¹ , and R ¹² represent hydrogen or an acyl group having the same or different carbon numbers from 12 to 18, and at least one of R ¹⁰ , R ¹¹ , and R ¹² is an acyl group. ) Specific examples of fatty acid esters of sucrose include the following compounds. That is, sucrose monolaurate, monomyristate, monopalmitate, monostearate, monooleate, monolinoleate, monolinoleate, monosinolate, dilaurate,
These include dimyristate, dipalmitate, distearate, dioleate, trilaurate, trimyristate, tripalmitate, tristearate, and trioleate. The above-mentioned sucrose fatty acid esters can be used alone or as a mixture of two or more. The organic polyisocyanate is used in an excess amount relative to the amine diol represented by the above general formulas () to (). Particularly preferred is 1.02 to 1.9 mol of organic polyisocyanate per 1 mol of amine diol. A urethane polymer having a terminal isocyanate group is obtained by the reaction of an amine diol and a polyisocyanate, and a tertiary nitrogen-containing urethane polymer having a sucrose fatty acid ester terminal group is obtained by reacting the terminal isocyanate group with a sucrose fatty acid ester. . A portion of the sucrose fatty acid ester may be present in an unreacted state. The amount of the tertiary nitrogen-containing urethane polymer thus obtained is a stabilizing amount, and it can be used in an appropriate amount depending on the required performance, but it is usually 0.01 to 15 parts by weight per 100 parts by weight of polyurethane. is preferred, and 0.1 to 5 parts by weight is particularly preferred. If the amount is too small, the effect will be insufficient, and if it is added in more than the required amount, it may cause scum during molding of the composition and post-processing of the molded product, which is inappropriate. The composition of the present invention may further contain an antioxidant such as a hindered phenol antioxidant or a hindered amine antioxidant and/or a UV absorber such as a benztriazole UV absorber, if desired. . In this case, it is particularly important to select additives that do not reduce gas discoloration resistance.
Particular examples of hindered phenol antioxidants that do not reduce gas discoloration resistance include compounds represented by the following general formulas () and/or (). (However, in the formula, R ¹³ represents an alkyl group, cycloalkyl group, neopentyl group, or aralkyl group, and R ¹⁴ and R ¹⁵ represent a group selected from a hydrogen atom, an alkyl group, and an alkoxy group.) General formula () Examples of phenolic compounds represented by are 1,3,5-tris(4-t-butyl-3-hydroxy-2,6-dimethylbenzyl)isocyanuric acid, 1,3,5-tris(4
-sec-butyl-3-hydroxy-2,6-dimethylbenzyl)isocyanuric acid, 1,3,5-
Tris(4-neopentyl-3-hydroxy-
Examples include 2,6-dimethylbenzyl)isocyanuric acid. 1,3,5-tris(4-t-butyl-
3-hydroxy-2,6-dimethylbenzyl)isocyanuric acid. Further, a particularly preferable example of the phenolic compound represented by the general formula () is R ¹³ having a branched carbon number of 4
~8 alkyl group, cycloalkyl group, neopentyl group or aralkyl group,
Further specific examples include: ●10-(2',6'-dimethyl-4'-t-butyl-3'-
hydroxybenzyl)-9,10-dihydro-9
-Oxa-10-Phosphor Afenethrene-10
-oxide●6-methyl-10-(2',6'-dimethyl-4'-t-
Butyl-3'-hydroxybenzyl)-9,10-
Dihydro-9-oxa-10-phosphaphenanthrene-10-oxide 6-methoxy-10-(2',6'-dimethyl-4'-t
-butyl-3'-hydroxybenzyl)-9,10
-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide●10-(2',6'-dimethyl-4'-cyclohexyl-
10-{2′,6′-dimethyl-4′-(α,α-dimethylbenzyl )-3′-hydroxybenzyl}-9,
10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide 10-(2',6'-dimethyl-4'-neopentyl-
Examples include 3'-hydroxybenzyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide. The amount of these phenolic compounds is a stabilizing amount against light, which is normally compared to polyurethane.
0.1-10% by weight, preferably 0.5-8% by weight. The polyurethane to which the present invention is applied is not particularly limited, and includes, for example, substantially linear polymers having active hydrogen-containing groups at both ends and having a molecular weight of 500 to 7,000, such as polyether diol, polyester diol, polycarbonate diol, Polylactone diol, polyamide diol, polyamide diamine, etc. and polyfunctional isocyanate such as 4,4'-diphenylmethane diisocyanate, 1,4-phenylene diisocyanate, 2,
4-tolylene diisocyanate, naphthalene diisocyanate, hexamethylene diisocyanate, 1,4-cyclohexane diisocyanate,
Xylylene diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, etc., and polyfunctional low-molecular active hydrogen compounds such as hydrazine, ethylenediamine,
1,2-propylene diamine, hexamethylene diamine, β-aminopropionic acid hydrazide, carbodihydrazide, water, ethylene glycol,
An example is a polyurethane having a urethane bond in the molecule obtained by reacting 1,4-butanediol or the like. The tertiary nitrogen-containing urethane polymer of the present invention can be added to polyurethane at any stage of producing polyurethane, but it is preferably mixed after the completion of polyurethane polymerization and before the molding stage. The polyurethane composition thus obtained can be formed into fibers, tapes, films, etc. by dry, wet or melt molding, and can also be used for foams, elastomers, synthetic leathers, paints, glass fiber sizing agents, etc. Particularly useful in clothing fiber and tape applications. The polyurethane composition obtained by blending the tertiary nitrogen-containing urethane polymer of the present invention has a characteristic that resistance to yellowing due to outside air conditions or gases such as combustion gas, and discoloration and deterioration due to chlorine are significantly improved. It also has the advantage of improved moldability, mold releasability, dyeability, etc. EXAMPLES Hereinafter, the present invention will be specifically explained with reference to Examples, but the present invention is not limited to the scope of these Examples. Note that parts and % in the examples indicate parts by weight and % by weight. In addition, the characteristic values in the Examples were measured as follows. Gas discoloration test for polyurethane fibers A strong test was conducted on 3 units in accordance with JIS L 0855-1976, and the b value before and after the test was measured using a color difference meter manufactured by Nippon Denshoku Kogyo Co., Ltd., ND-101D, and the change (Δb) was The degree of discoloration is expressed. Chlorine embrittlement test of polyurethane fibers 40 denier polyurethane fibers with an inner diameter of approximately 8 mm.
Place it in a glass tube about 1m long and close one end.
Regular tap water containing approximately 0.1 to 0.5 ppm of sterilizing chlorine was continuously flowed at a flow rate of approximately 2/min, and each sample was taken out at 12, 24, 36, and 48 hours from the start of the test and heated to 80℃. After drying for 2 hours, the breaking strength was measured using a tensilon measuring machine, and the test time (T1/2) at which the strength was halved was determined from the strength change curve. Example 1 1950 parts of polytetramethylene ether glycol having a molecular weight of 1950 and 500 parts of 4,4'-diphenylmethane diisocyanate were reacted at 70°C for 60 minutes to obtain a prepolymer having isocyanate groups at both end groups. . 4478 parts of dimethylformamide was added to this and dissolved to make a homogeneous solution. This solution was cooled to 0°C and a 46% paste of titanium oxide pigment containing a small amount of blue-tinting pigment dispersed in dimethylformamide was prepared.
A chain extension reaction was carried out by adding 145 parts of 1,2-propylene diamine and then slowly adding a solution of 74 parts of 1,2-propylene diamine dissolved in 983 parts of dimethylformamide with stirring. 90% of the 12-propylene diamine solution was added to reach 2500 poise at 25°C. At this point 12 parts of monoethanolamine dissolved in 72 parts of dimethylformamide are added to quench the free isocyanate in the polymer solution, and then 10 parts of acetic anhydride dissolved in 72 parts of dimethylformamide are added to reduce the viscosity of the polymer solution. stabilized. Obtained solids content 32%, viscosity 2200 at 25°C
Let the polymer solution of Poise be A dope. Separately, 109 parts of 4,4' dicyclohexylmethane diisocyanate was dissolved in 500 parts of dimethylformamide, 1.0 x 10 ^-2 parts of dibutyltin diacetate was added, and the temperature was raised to about 62°C with stirring. While stirring and maintaining the temperature, 55.1 parts of 2-ethyl-2dimethylamino-1,3-propanediol was gradually added, and after the entire amount had been added, the reaction was continued with stirring at 62°C for 5 hours. Further, 59 parts of sucrose fatty acid ester was added to this reaction mixture, and the mixture was reacted at 62°C for about 3 hours with stirring. The sucrose fatty acid ester used at this time was a mixture of monoester and di- and triester, and the types of fatty acids included stearic acid and palmitic acid. The resulting tertiary nitrogen-containing polymer was a light brown solution of 2.5 centipoise at 30°C. The tertiary nitrogen-containing urethane polymer thus obtained was added to the A dope so that the content of tertiary nitrogen per 1 kg of polyurethane was 80 meq.
-Tris(4-t-butyl-3-hydroxy-
2,6-dimethylbenzyl)isocyanuric acid
0.32 parts was added to 100 parts of the above dope and dry spun by a conventional method to obtain a 40 denier polyurethane fiber. The results of the gas discoloration test and chlorine embrittlement test of the obtained fibers are shown in Examples 2 and 3 and Comparative Examples 1, 2, and 3.
They are shown in Table 1. Example 2 471 parts of 4,4' dicyclohexylmethane diisocyanate was dissolved in 1112 parts of dimethylformamide, and after adding 0.15 parts of dibutyltin diacetate, the temperature was raised to about 65°C, and the temperature was maintained at 221°C while stirring. 1 part of 4-methyl-4-aza-2,6-heptanediol was gradually added, and after the entire amount had been added, the mixture was kept at about 65°C for about 6 hours while stirring.
Add 420 parts of sucrose fatty acid ester, and add about 65 parts of sucrose fatty acid ester.
The reaction was carried out at °C for about 3 hours to obtain a urethane polymer containing tertiary nitrogen. This polymer solution was brown in color and had a temperature of about 1.9 poise at 30°C. The tertiary nitrogen-containing urethane polymer thus obtained was added to the A dope so that the tertiary nitrogen content was 80 milliequivalents per 1 kg of polyurethane, and further 10-
Add 0.32 part of (2',6'-dimethyl-4'-t-butyl-3'-hydroxybenzyl)-9,10-dihydro-9-oxa-10-phosphorphenanthrene-10-oxide to the above solution. - 40 denier polyurethane fiber was obtained by dry spinning using a conventional method. Example 3 437 parts of 4,4' dicyclohexylmethane diisocyanate was dissolved in 910 parts of dimethylformamide, and after adding 0.15 parts of dibutyltin diacetate, the temperature was raised to about 63° C. with stirring and the temperature was maintained. Gradually add 242 parts of 4-ethyl-4-aza-2,6-heptanediol while stirring, and after the entire amount has been added, keep at about 60°C for about 5 hours while stirring, and then add sucrose fatty acid ester 231 of the mixture was added, and the mixture was reacted at 60°C for about 3 hours with stirring.
The obtained tertiary nitrogen-containing urethane polymer was heated to 30°C.
It was a viscous solution of 2.5 poise. This tertiary nitrogen-containing urethane polymer was added to the A dope so that the tertiary nitrogen content was 80 milliequivalents per 1 kg of polyurethane, and 10-(2',6'-dimethyl-4'-cyclohexyl-3' -hydroxybenzyl)-9,
0.32 parts of 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide was added to 100 parts of A dope and dry-spun to obtain a 40-denier polyurethane fiber. Comparative Examples 1 to 2 When no additive is added to the A dope of Example 1 (Comparative Example 1), 1,3,5-tris(4-t-butyl-8-hydroxy-2,6-dimethyl When only 0.32 parts of benzyl) isocyanuric acid was added to 100 parts of A dope (Comparative Example 2), poly(N-diethylaminoethyl methacrylate) was added to Comparative Example 2 per 1 kg of polymer, and the tertiary nitrogen content was 80 mlg. /Kg (Comparative Example 3), each was dry-spun in the same manner as Examples 1 to 3 to obtain a 40-denier polyurethane fiber.

【table】

[Table] From the above results, it can be seen that the polyurethane composition of the present invention has a remarkable effect on gas discoloration due to outside air conditions and chlorine deterioration.

Claims (1)

[Scope of Claims] 1. A polyurethane composition characterized in that a stabilizing amount of a tertiary nitrogen-containing urethane polymer end-capped with a sucrose fatty acid ester is blended into polyurethane. 2. The polyurethane composition according to claim 1, wherein the amount of the tertiary nitrogen-containing urethane polymer is 0.01 to 15 parts by weight per 100 parts by weight of the polyurethane.