JPS5845983B2 - Polyurethane compositions stabilized against color degradation - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to polyurethane compositions stabilized against color degradation.

Polyurethane provides a wide range of useful materials by taking advantage of its functional characteristics, such as foam elastomer, elastic thread, leather, adhesive, and paint, but it can be colored or deteriorated by sunlight or combustion gas. Are known.

It is well known that these problems occur not only in polyurethane products but also in their manufacturing and processing processes, and are said to be one of the essential defects of polyurethane.

It has been known to add antioxidants, ultraviolet absorbers, and aliphatic amines to prevent polyurethane from discoloring and deteriorating.

However, there is no conventional stabilizer for polyurethane that satisfies both light emission and gas resistance, and those that have a light emission effect often act as a staining agent when it comes to gas resistance.

In particular, phenolic antioxidants such as 4,47-butyldenbis-6-t-butyl-m-cresol have an excellent effect on deterioration caused by ultraviolet rays, but when added to combustion gases, yellowing is accelerated. It has the disadvantage of being

As a result of extensive research in order to overcome these difficulties, the present inventors have discovered a compound that is extremely effective against color deterioration caused by light and is less susceptible to gas contamination. It's arrived.

That is, the present invention refers to a polyurethane having the general formula () [wherein R1 is a C1-4 alkyl group or a phenyl group, and R2 is a C1-4 alkyl group.

Further, R1 and R2 may be combined to form a ring.

R3 represents an alkyl group of 01 to 4, a cycloalkyl group, a phenyl group, an alkyl group of *, or a hydrogen atom, and R1 and R2 represent the same group as defined above.

). ] The object of the present invention is to provide a polyurethane composition that exhibits excellent resistance to discoloration and deterioration by containing the phenolic compound represented by the above formula and an alkaline earth metal such as lactic acid.

Traditionally, it has been used as an antioxidant for synthetic resins and synthetic fibers.
Phenolic antioxidants in which the ortho position of the hydroxyl group is substituted with a substituent having a high degree of steric hindrance have been frequently used, but even when such compounds are incorporated into polyurethane,
Its deterioration prevention effect was hardly worth seeing.

On the other hand, phenolic antioxidants that have a substituent with less steric hindrance at the ortho position may be effective in preventing deterioration, but they may be colored by combustion gas and cause pollution. There were a lot of them, and I could hardly find anything that could be put to practical use.

However, a compound having a moderately hindered hydroxyl group, such as the phenolic compound of the present invention, has been found to have very satisfactory effects in preventing deterioration and preventing discoloration.

Furthermore, it has been found that when the hydroxyl group is substituted with a substituent such as an alkyl group, phenyl group, or cycloalkyl group at the rose position, the coloring prevention effect is further improved.

Examples of the compound represented by the general formula (I) used in the present invention include: and the like.

These compounds may be used alone or in combination of two or more.

Among the compounds represented by the general formula (I), compounds in which R1 is a phenyl group and compounds in which R1 and R2 are bonded to form a ring have good compatibility with polyurethane,
It is particularly preferred because the effect lasts.

On the other hand, compounds having a methyl group or t-butyl group at the ortho position such as these do not produce the effects of the present invention.

Further, it is particularly preferable to use the compound represented by the general formula (■) in the present invention in combination with an alkaline earth metal salt of lactic acid, since the effect of preventing deterioration and discoloration is improved several times.

Alkaline earth metal salts may be used alone or in combination of two or more.

The compound represented by formula (I) has the following properties for polyurethane:
It is added in an amount of 0.1% to 10.0% by weight, but 10.
Adding more than 0% by weight does not improve the effect, and the polymer itself becomes plastic, so it is preferably up to 10.0% by weight.

Further, the compound represented by formula (I) and the alkaline earth metal salt of lactic acid can be added together in any ratio, but preferably in a weight ratio of 5:1 to 1:5. The total amount added is 10.0% by weight based on the polyurethane.
If it is more than that, plasticization will start, so it is better if it is less than that.

The polyurethane used in the present invention is a substantially linear polymer having hydroxyl groups at both ends and a molecular weight of 600 to 5,000, such as polyester, polylactone, polyether, polyesteramide, polythioether, polyhydrocarbon, or Mixtures thereof: those whose main constituents are organic diisocyanates and chain extenders having polyfunctional active hydrogen atoms, such as hydrazine, polyhydrazide, polysemicarbazide, polyol polyamines, hydroxylamine, etc.

The compound represented by the general formula (I) of the present invention and the alkaline earth metal salt of lactic acid can be mixed at any stage of the polyurethane production process, but preferably, they are added after the final polymer is produced. It's good.

The composition of the present invention can also be used in combination with conventionally known ultraviolet absorbers, antioxidants, dyes, pigments, and the like.

EXAMPLES The embodiments of the present invention will be described below with reference to Examples in order to further clarify the aspects thereof, but the scope of the present invention is not limited by the Examples.

In addition, all parts in the examples refer to parts by weight.

Example 1 An intermediate polymer was obtained from 150.0 parts of polycaprolactone having an average molecular weight of 1500 and 45 parts of 4,4'-diphenylmethane diisocyanate.

After dissolving in dimethylformamide, a dimethylformamide solution containing 8.7 parts of 1,4-cyclohexanediamine and 0.5 parts of N-N-diethylaminopropylamine was added to react.

To the polymer solution thus obtained were added an amount of titanium oxide equivalent to 4% based on the solid content of the polymer and a predetermined amount of the additive shown in Table 1, and the mixture was thoroughly stirred.

This was dry-spun using a conventional method to obtain an elastic yarn of 140 denier.

Each yarn was subjected to an ultraviolet irradiation test using a fade meter to measure discoloration and strength retention.

Furthermore, A4TCC23 underwent a fastness test using nitrogen oxide gas.
1962, the colorability was judged visually using a gray scale, and was graded as 1st grade, 2nd grade, etc. based on the colorability of the dog.
・・・・・・It was set as 5th grade.

Furthermore, thread, new beads 5? /l: for 5 minutes, washed with water, and then subjected to a light test after drying to examine changes in strength retention due to washing.

The results are shown in Table 2.

As shown in Table 2, it can be seen that the phenolic compound and the alkaline earth metal salt of lactic acid each have considerable performance when used alone, but when both are used in combination, a remarkable effect is obtained.

Claims (1)

[Scope of Claims] 1 Polyurethane having the general formula (I) [However, in the formula, R1 is an alkyl group of 01 to 4 or a phenyl group, and R2 represents an alkyl group of C1. Further, R1 and R2 may be combined to form a ring. R3 is C
1 to 4 alkyl groups, cycloalkyl groups, phenyl groups,
or represents an alkyl group or a hydrogen atom, and R1 and R2 are the same groups as defined above. ). A polyurethane composition containing a phenolic compound represented by the following formula and an alkaline earth metal salt of lactic acid. 2. The polyurethane composition according to claim 1, wherein the weight ratio of the phenolic compound of general formula (I) to the alkaline earth metal salt of lactic acid is 5:1 to 1:5.