JPS6140340A - Stabilizer for polyurethane - Google Patents

Abstract

PURPOSE:To provide a stabilizer consisting of a reaction product of a tertiary amine and/or hydrazine with an isocyanate and a compound containing perfluoroalkyl group, and exhibiting excellent effect to prevent the discoloration and the lowering of the strength of a polyurethane caused by sunlight, heat and nitrogen oxide. CONSTITUTION:The objective stabilizer is prepared by reacting (A) a tertiary alkylamine (preferably tert-butylamine, etc.) and/or an N,N-dialkylhydrazine (preferably N,N-dimethylhydrazine, etc.) with (B) an alcohol and/or amine containing perfluoroalkyl group) and (C) a compound having isocyanate group at the terminal and having an average molecular weight of 170-2,500 in a solvent at 40-80 deg.C. The equivalent ratio of (A+B)/C is (95-105)/100, and that of A/B is 90/10-50/50. 0.5-35pts.(wt.), preferably 3-18pts. of the stabilizer is added to 100pts. of a polyurethane.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for stabilizing polyurethane that reduces discoloration and deterioration due to sunlight, ultraviolet rays, heat, nitrogen oxides, etc. in the presence of air.

(Prior art) Generally produced by isocyanate addition polymerization method from a polyhydroxy compound and polyisocyanate, optionally in the presence of glycols, water, hydrazine, polyamine, or other molecular chain extenders. Polyurethane has excellent mechanical properties and is used in a wide range of applications, including fibers, films, coatings, laminates, foam plastics, and elastomers.

However, such polyurethanes are generally exposed to sunlight,
It has the disadvantage of gradually yellowing due to exposure to ultraviolet rays, heat, nitrogen oxides, etc., and this discoloration is often accompanied by deterioration of mechanical properties.

Although it is generally known that polyurethanes obtained using aliphatic diisocyanates have relatively little linear discoloration, they suffer from the drawbacks of low reactivity and low mechanical properties of the polyurethanes produced. On the other hand, polyurethanes obtained using industrially useful aromatic polyisocyanates that provide polyurethanes with high reactivity and excellent mechanical properties are susceptible to yellowing and deterioration. In particular, applications with large surface areas such as foamed plastics, fibers, films, etc., and applications such as coating materials used to protect other materials from sunlight, water, slag, polluted air, etc. When used in sunlight, oxygen, heat,
Since it is more affected by nitrogen oxides and the like, it is more likely to cause discoloration and deterioration of its strength, so stabilizing polyurethane used in these applications has become an important issue.

Therefore, attempts have been made to add various stabilizers to stabilize polyurethane, but in addition to their stabilizing effect, stabilizers must not interfere with the diurethanization reaction that occurs with the raw materials of polyurethane resin. It is required that it is not colored itself, that it has good compatibility with polyurethane, that it is preferably soluble in the polyurethane solvent, and that it is not extracted by cedar that oozes out from the polyurethane after addition, or by water, etc. These requirements can be fully satisfied. je IJ taurethane stabilizers have not yet been developed.

(Problems to be Solved by the Invention) Typical conventional stabilizers for polyurethane include, for example, hydrazine or a reaction product of tertiary amine and isocyanate, which is effective for stabilizing against sunlight and heat. However, this stabilizer has insufficient stabilizing effect against nitrogen oxides, and furthermore, when used in the wet film forming method, which has recently become popular in artificial leather dam construction, etc. Dimethylformamide (DMF) is added to the membrane.
), it is easily extracted into the water, and a sufficient stabilizing effect cannot be obtained.

(Means for solving the problem) As a result of intensive studies in view of the above-mentioned situation, the present inventors added a perfluoroalkyl group to the conventional reaction product of tertiary amine and/or hydrazine and isocyanate. It was discovered that when the introduced reactant was used as a stabilizer, a lIJ taurethane stabilizer free from the above-mentioned drawbacks could be obtained, and the present invention was completed.

That is, the present invention comprises (3) a tertiary alkylamine and/or an N,N-dialkylhydrazine, and (B) an alcohol containing a fluoroalkyl group and/or
Also, an amine containing a fluoroalkyl group, and (C)
The present invention provides a stabilizer for polyurethane characterized by being composed of a reactant with a compound having an isocyanate group at the end.

The tertiary alkylamine used in the present invention has the following general formula (wherein R1, R2, and R5 are alkyl groups and 1R
The total number of carbon atoms in +H+H is 3 to 10), and preferred examples include tertiary butylamine [in the general formula (I), R=R
=R=CH3), tertiary octylamine [general formula (I)
In R1= R' = CH3I R2=n-c6
u13:) etc.

In addition, N,N-dialkylhydrazine is defined by the following general formula (wherein R' + R'' is an alkyl group that may have a substituent at the end, and the total number of carbon atoms of R4 + H5 is 2 to 1.
0 compounds are shown), and preferred examples include N r N-dimethylhydrazine [general formula (II)
In the general formula (l[), R'=R5=CH3:], N,N-dialkylhydrazine [in the general formula (l[), R'=
Examples include R5=CH2CH20HI.

The perfluoroalkyl group-containing alcohol and per70-roalkyl group-containing amine used in the present invention are represented by the following general formula % formula % () [However, Rf in the formula is a linear or branched chain having 6 to 12 carbon atoms. Tuber 70 loalkyl group, X is an alkylene group or arylene group having 1 to 6 carbon atoms, (-R-0+n (however, R
represents an alkylene group having 1 to 3 carbon atoms, n represents an integer of 1 to 6), -〇-@- represents an alkyl group or hydroxyalkyl group having 4 to 4),
or a divalent bonding group combining these, Y is 10H, -
NH2 or -■, n is Y is 10I (or -■2, 1
, when Y is 1, represents 2]. Specific examples thereof include the following compounds.

C6F, 3CH2CH20H, C3F1. CH2CH2
0H.

CI(3C,I(.

08F17S02N (CH2CH20H) 2°08F,
7802N(CH2CH20)2CH2CH20H1907F, 5CONHCH2CH20H1C6F, 3SO
2NHCH2CHCH20H2 Akita, OH.

CH2O,H.

(C8F 1,802NCH2CH2+2 old, C6F
, 3CH2CH2Nu21908F, 7CH2CH2NH Compounds having an isocyanate group at the end used in the present invention include, for example, tolylene diisocyanate, diphenylmethane-4,4'-diisocyanate, hexamethylene diisocyanate, inphorone diisocyanate,
In addition to diisocyanate compounds such as dicyclohexylmethane-4,4'-diisocyanate, those with relatively simple molecular structures such as tolylene diisocyanate trimer, and hexamethylene diisocyanate trimer, 1 mol of trimeterolpronogun tolylene diisocyanate Also included are solpolymers having terminal isocyanate groups obtained by the reaction of a polyvalent isocyanate compound such as a reaction product with 3 moles of *-t and a compound having a hydroxyl group or an amine group. The average molecular weight of the compound having an isocyanate group at its terminal is preferably 170 to 2,500, which is practical in view of compatibility with polyurethane and stabilizing effect against sunlight, ultraviolet rays, heat, and nitrogen oxides.

A compound having a tertiary alkylamine and/or N,N-dialkylhydrazine (5) of the present invention, an alcohol containing a fluoroalkyl group and/or an amine containing a per-70-roalkyl group (B), and an isocyanate group at the terminal (
The stabilizer made by reacting C) with (prison+ωmonth/(
C) = 95/100 to 105/100, (4)/
It is obtained by reacting at an equivalent ratio of ω) = 90/10 to 50AO, especially (A)/(B) = 75/25 to 6.
Reactants reacted in an equivalent ratio of 5/350 are preferred.

The amount of the stabilizer of the present invention added is usually 0.5 to 35 parts by weight, preferably 3 to 1 parts by weight, per 100 parts by weight of polyurethane.
It is 8 parts by weight. If the amount of the stabilizer added is less than 0.5 parts by weight, a sufficient stabilizing effect cannot be obtained, and if it is used in an amount exceeding 35 parts by weight, no improvement in the stabilizing effect can be expected, which is not preferable.

The method of reacting each component (5), (B) and (C) above is not particularly limited, but may be carried out at 40 to 80°C in a solvent.
Generally, the reaction is carried out in the same manner as the reaction between an ordinary isocyanate and an active hydrogen-containing compound.

(Effects) The stabilizer of the present invention thus obtained remains transparent or translucent, or after removing the solvent, becomes a white or pale yellow solid or resin, and is well compatible with polyurethane, even at high temperatures. It is a stable substance that does not decompose and is exposed to sunlight, ultraviolet light, heat, and nitrogen oxides. ! ? +J Shows excellent preventive effects against urethane discoloration and strength deterioration. Furthermore, since it is not extracted by water, it has the advantage of exhibiting extremely excellent effects even in wet film formation methods. Moreover, it is chemically neutral and does not affect the urethanization or reticulation reactions and can be applied at any stage of polyurethane production and use. Of course, two or more of these reactants may be used in combination as desired, or other known methods may be used. It can also be used in combination with a stabilizer for urethane.

(Action) Although the stabilizing mechanism of the stabilizer of the present invention against sunlight, ultraviolet rays, heat, and nitrogen oxides has not yet been elucidated, (4) and (C' ) mainly exhibits a stabilizing effect, and the perfluoro groups of (B) are arranged neatly on the surface of the urethane film, which is easily affected by sunlight, ultraviolet rays, heat, and nitrogen oxides, making it extremely efficient. This is thought to be because it can exert a stabilizing effect.

(Example) The present invention will be explained in more detail by giving Examples, Comparative Examples, and Test Examples below. In addition, all parts and units in the examples are based on weight.

Further, the tests in the examples were conducted as follows.

Light resistance test: The sample is irradiated with ultraviolet rays for 40 to 140 hours using a Nikagin arc fade meter (manufactured by Suga Test Instruments), and the discoloration of the sample is visually evaluated.

Heat resistance test: Place the sample in a gear oven at 120℃ for 200 minutes.
Leave the sample for some time and visually evaluate the discoloration of the sample.

Nitrogen oxide resistance test: Based on JIS-L-0855, 3 units are exposed to a nitrogen dioxide gas atmosphere, and discoloration of the sample is visually evaluated.

The visual evaluation criteria for each of the above tests are as follows: ◎: Extremely good (no discoloration) ○: Good (light yellow) Δ: Slightly poor (yellow) ×: Poor (brown) Real: Extremely poor (brown) (brown color, resin deterioration) Examples 1 to 4 The solvent shown in Table 1, component (B) and (C) were placed in a flask.
Prepare the ingredients and react at 60°C for 2 hours while stirring,
Next, component (4) shown in Table 1 was added dropwise over 30 minutes while cooling the inside of the flask to 50°C or below, and then further heated at 50°C for 1 hour.
The reaction was carried out for a period of time to obtain a pale yellow, transparent and viscous stabilizer solution (I) for polyurethane of the present invention with a non-volatile content of 60%. In addition, the prepolymer (&) used as component (C) in Table 1
and (b) are the playrimers shown below.

Prepolymer (a): )! A prepolymer having isocyanate groups at the terminals (non-volatile content: 75 yen) obtained by reacting 67 parts of J-methylolpropane and 252 parts of hexamethylene diisocyanate in 106 parts of methyl ethyl ketone (hereinafter abbreviated as MEK).

Prepolymer (b): 30 parts of 1,3-butanediol,
A sol polymer having isocyanate groups at the terminals (nonvolatile content: 75 t) obtained by reacting 9789.3 parts of trimethylol zolo and 348 parts of tolylene diisocyanate in 155.7 parts of ethyl acetate.

Example 5 278 parts of H3 were charged, and hexamethylene diisocyanate trimer was added dropwise over 30 minutes while stirring while cooling the inside of the flask to 50° C. or lower. Next, while cooling the inside of the flask to below 50°C, 36.5 parts of tertiary butylamine, N, and N were added.
- A mixture of 30 parts of dimethylhydrazine was added dropwise over 1 hour, and the mixture was further reacted at 50°C for 1 hour to achieve a non-volatile content of 60%.
Colorless transparent viscous stabilizer solution for polyurethane of the present invention 1f
Lci) was obtained.

Comparative Example 1 A flask was charged with 165 parts of MEK and 73 parts of tertiary butylamine, and while the inside of the flask was cooled to 50°C or lower, 174 parts of tolylene diisocyanate trimer was added dropwise over 30 minutes with stirring, and further 5°C. The reaction was carried out at .degree. C. for 1 hour to obtain a pale yellow viscous stabilizer solution (1') for polyurethane for comparison with a non-volatile content of 60%.

Comparative Example 2 518 parts of dimethylformamide, C3F1,
5o2NCH2CH20H167, 1 part and prepolymer OH.

-(a) 85.1 parts were charged and reacted at 60° C. for 2 hours with stirring to obtain a pale yellow comparative/urethane stabilizer solution (■') with a non-volatile content of 30.

Test/Test Example 1 27 parts of 1,4-butanediol were thoroughly mixed at 80°C with 200 parts of a polyester having a molecular weight of 1000 and having a hydroxyl group at the end obtained from 1,4-butanediol and adipic acid, and 45 Diphinylmethane kept at 4.4'
- 123.8 parts of diisocyanate was added and stirred vigorously, and the reaction product, which had become viscous with a diameter of 2 mm, was quickly poured out into a vat. Next, this was aged in an open air at 90° C. for 10 hours, and then cooled, and the obtained polyurethane elastomer was crushed into chips. This polyurethane chip 7
Dissolved in dimethylformamide at 0°C, non-volatile content 20
It was made into a viscous polyurethane solution.

Next, to this /IJ urethane solution, stabilizers for polyurethane (I) to (to) obtained in Examples 1 to 5 and Comparative Examples 1 to
Add any one of the polyurethane stabilizers (■su~(■') Sanol LS-770 (stabilizer manufactured by Ciba Geigy) obtained in step 2 in the proportions shown in Table 1 and dissolve it sufficiently uniformly. on release paper and heated at 120℃ for 3 minutes.
Then, it was dried at 150° C. for 3 minutes to obtain a transparent stabilizer-containing I-urethane film with a thickness of 0.06 m prepared by a dry method. A polyurethane film containing no stabilizer was also prepared in the same manner.

Table 1 shows the results of the light resistance test, heat resistance test, and nitrogen oxide resistance test of these films.

7', / Test Example 2 It has a molecular weight of 2000 obtained from 1,4-butanediol and adipic acid and has a hydroxyl group at the end. l IJ ester 2
A non-volatile content of 20L16 was prepared in the same manner as in Test Example 1, except that 50 parts, 1,4-butanediol, 33.8 parts, and 122,5 parts of diphenylmethane-4,4'-diisocyanate were used.
A polyurethane elastomer solution was obtained, and each stabilizer was added thereto in the proportions shown in Table 2, and the stabilizers were uniformly dissolved.

A 1 mm thick lIJ ester nonwoven fabric was fully impregnated with this solution, passed through a mangle roll with a clearance of 0.7 mm, and immersed in a water bath at 20° C. for 5 minutes. After washing with warm water at 50° C. for 30 minutes, the film was dried at 120° C. for 10 minutes to obtain a stabilizer-containing polyurethane elastomer film with a thickness of 0.6 mm prepared by a wet film forming method. Also,
A polyurethane elastomer film containing no stabilizer was similarly prepared.

Table 2 shows the results of the light resistance test, heat resistance test, and nitrogen oxide resistance test of these films.

Table 2 Example 6 A flask was charged with 61 parts of MEK and 24,663 parts of 08F, 7C Ma C ■, and 40 parts of polyoxypropylene glycol with a molecular weight of 400 and (tolylene diisocyanate)
34.8 parts of MEK in 25 parts of MEK to obtain 99.7 parts of a prepolymer (non-volatile content 75%) having isocyanate groups at the ends was stirred while cooling the inside of the flask to 50°C or less. It was added dropwise over 30 minutes. Next, while cooling the inside of the flask to below 50°C, 7.3 parts of tertiary butylamine was added dropwise over 1 hour. After further reaction at 50°C for 1 hour, MEK was removed by vacuum distillation, and the nonvolatile content was 99%. .71 of the polyurethane stabilizer M of the present invention in the form of a pale yellow resin was obtained.

Test Example 3 To 100 parts of polyoxyzolopyrene triol with a hydroxyl value of 56 obtained by adding propylene oxide to trimethylolpropane, 18 parts of polyurethane stabilizer (7) and 3 parts of water were added.
1 part, 0.15 parts of triethylene 2F, 0.3 parts of tin octylate, and 40 parts of silicone oil were mixed, and then 40 parts of tolylene diisocyanate were added and vigorously stirred to produce polyurethane foam. Separately, polyurethane foams containing no stabilizer were prepared in the same manner, and both foams were cut into plates of thickness α and subjected to a light resistance test, a heat resistance test, and a nitrogen oxide resistance test. The results are shown in Table-3.

Table-3

Claims (1)

[Scope of Claims] (A) a tertiary alkylamine and/or an N,N-dialkylhydrazine; (B) a perfluoroalkyl group-containing alcohol and/or a perfluoroalkyl group-containing amine; (C) a terminal A stabilizer for polyurethane characterized by comprising a reactant with a compound having an isocyanate group.