JPS58120646A - Stabilized synthetic resin composition - Google Patents

Abstract

PURPOSE:To prepare a synthetic resin composition having extremely excellent stability to light, by compounding a hindered piperidine compound represented by a specific structural formula to a synthetic resin. CONSTITUTION:The objective composition is prepared by compounding 100pts.wt. of a synthetic resin such as low-density polyethylene, high-density polyethylene, polypropylene, etc. with preferably 0.05-2pts.wt. of a hindered piperidine compound of formula (R1 is H or methyl; R2 is 1-3C alkyl). Preferably, an antioxidant such as a phenolic antioxidant (e.g. 2,6-di-t-butyl-4-methylphenol), a phosphite-type antioxidant. (e.g. tris(nonylphenyl) phoshite), etc. is added to the composition.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a synthetic resin composition having excellent stability against light.

It is well known that synthetic resins such as polyethylene, polypropylene, polyvinyl chloride, polyurethane, and ABS resins are degraded by light and their physical properties are significantly reduced, accompanied by phenomena such as softening, brittleness, and discoloration. . In order to prevent such deterioration due to light, various light stabilizers have been conventionally added and used during the manufacturing and processing steps of synthetic resins.

Such light stabilizers include, for example, 2-hydroxy-
4-methoxybenzophenone, 2-hydroxy-4-n
-Octoxybenzopheno7.2 (2'-hydroxy-
5'-methylphenyl)benzotriazole, 2(2'
-Hydroxy-3'-t-butyl-5'-methylphenyl)-5-chloro-benzotriazole, 2(2'-hydroxy-S#, 5#-dibentylphel)sancitriazole, ethyl-2-cyano -3,3-diphenylacrylate, 2,4-di-t-butylphenyl-
3,5-di-t-butyl-4-hydroxybenzoate, [2,2'-thiobis(4-t-octylphenolad))-n-butylamine nickel (fi+, bis(3
, 5,-di-t-butyl-4-hydroxybenzylphosphoric acid) monoethyl ester, N1 salt, bis(
2°2,6.6-tetramethyl-4-piperidyl) sebacate and the like are known. However, these light stabilizers are still not fully satisfactory in terms of light resistance.

The present inventors sought to solve these problems (as a result of various studies, they found that by blending a specific hindered piperidine compound into a synthetic resin, extremely superior light resistance could be obtained compared to conventional light stabilizers). The present invention was based on the discovery that this can be done.

That is, the present invention provides a stabilized synthetic resin composition characterized by blending a compound represented by the following general formula CI) into a synthetic resin.

(In the formula, k□ represents a hydrogen atom or a methyl group, k,
represents an alkyl group having 1 to 3 carbon atoms. ) Examples of the compounds of general formula (I) used in the present invention are shown in Table-1.

Table 1 A compound represented by the general formula (1) is synthesized from a compound represented by the following general formula (11) and a compound represented by the general formula (l[).

(In the formula, Ko represents a hydrogen atom or a methyl group.) 0 (In the formula, R2 represents an alkyl group having 1 to 3 carbon atoms.) Composition of the synthetic resin of the present invention In products (the amount of formula 11 compound is usually 0.01 to 5 parts by weight per 100 parts by weight of synthetic resin)
The amount is 5 parts by weight, preferably 0.05 to 2 parts by weight.

In the present invention, in order to blend the compound of formula (■) into the synthetic resin, the known equipment and operating methods for mixing and blending stabilizers, pigments, fillers, etc. into thermoplastic resins can be applied almost as they are.

The synthetic resin composition of the present invention may contain other additives, such as antioxidants, light stabilizers, metal deactivators.

It may contain metal soaps, nucleating agents, lubricants, antistatic agents, flame retardants, pigments, fillers, and the like.

In particular, the addition of phenolic antioxidants can improve thermal and oxidative stability. Examples of these phenolic antioxidants include 2,6-
Di-t-butyl-4-methylphenol, n-octadecyl-! -(3,5-di-t-butyl-4-hydroxyphenyl)propionate, 1,1.3-)lis(2-
Methyl-4-human tetraxy-5-t-butylphenyl)butane, 1,3.5-)limethyl-2,4,,6-)lis(3,5-di-t-butyl-4-hydroxybenzyl)
Benzene, 1°3.5-)lis(3,5-di-t-butyl-4-hydroxypenzyl)isocyanurate, 1°3.5-)lis[β-(3,5-di-t- Butyl-4-
hydroxyphenyl)propionyloxyethyl]isocyanurate), 1,3,5-tris(2,6-di-methyl-3-hydroxy-4-t-butylbenzyl)isocyanurate, pentaerythritol-tetrakis[β-
(3゜5-di-1-butyl-4-hydroxyphel)
Propionate], etc.

Further, by further adding a phosphite-based antioxidant to the synthetic 8 resin composition of the present invention, its hue can be improved. These ho.

Examples of sulfite antioxidants include tris(nonylphenyl)phosphite, distearylpentaerythritol diphosphite, tris(2,4-di-t-
butylphenyl) phosphite, tris(2-butyl-4-methylphenyl) phosphite, bis(2,4
-di-t-butylphenyl diphosphite, tetrakis(2,4-di-t-butylphenyl)-4,4'-hyphenylene diphosphonite, and the like.

A sulfur-based antioxidant may also be added to the synthetic resin composition of the present invention. These sulfur-based antioxidants include, for example, dilaurylthiodipropionate, simiristylthiodipropionate, distearylthiodipropionate, pentaerythritol tetrakis (β
-laurylthiopropionate), pentaerythritol-tetrakis (β-hexylthiopropionate), and the like.

Synthetic resins stabilized by the present invention include low-density polyethylene, high-density polyethylene, linear low-density polyethylene, chlorinated polyethylene, EVA resin, polypropylene, polyvinyl chloride, methacrylic resin, polystyrene, high-impact polystyrene, and ABS. resin, ACS resin,
Examples include MBS resin, polyethylene terephthalate, polybutylene terephthalate, polyamide, polyimide, polycarbonate, polyacetal, polyurethane, and unsaturated polyester resin.

Next, the present invention will be described in detail with reference to Reference Example # and Examples, but the present invention is not limited thereto.

Reference example Synthesis of (1-1) 2,2,6.6-tetramethyl-4-a (noviveridin?, 8 f (0.05 mol) and methyl acrylate 5
．． 6 9 (o.oas mol) and 50g of methanol
The mixture was reacted under reflux for 3 hours.

Distill the solvent & remove 130~b as a colorless liquid of methyl 2,2,6.6-tetramethyl-4-piberidylaminopropionate8. Obtained Of.

In the infrared absorption spectrum of this product, strong absorption at 1750 cm-1 corresponding to C=0 of the ester, which is not observed in the raw material, was observed. By the way, the C of the raw material methyl acrylate
The absorption of I+=0 is 1760c&-1 and 1740cm-
There were 2 of 1.

Example 1 The following compound was mixed with a mixer for 5 minutes and then melted and kneaded with a 180°C mixing roll. The resulting compound was molded into a 1 m thick sheet using a hot press at 210°C.
A test piece of 0×30×1× was prepared.

This test piece was irradiated with light in a sunshine weather meter (light source: carbon arc, black panel temperature: 83 ± 3°C, spray cycle: 120 minutes, spraying for 1 hour: 18 minutes), and at 60 o'clock, the open silver became shrimp-like. The weather resistance was evaluated by bending and measuring the time it took to break.

The results are shown in Table-1.

Composition> Unstabilized polypropylene 100 weight 185 calcium stearate 0.1 part by weight.

Test mixture 0.2 Nao, on the table: # LN te UV, A-1 ~ UV
A-8 represents the following compound.

UVA, 1 2-hydroxy-4-methoxybenzophenone υVA-2 2-hydroxy-4-n-octoxybenzophenone UVA, -3 2(2'-hydroxy-5'-methylphenyl)benzotriazole UVA-4 2(2I- Hydroxy-3'-1-butyl-5'-methylphenyl)-5-chloro-benzotriazole UVA=5 2(2'-hydroxy-3',5'-dibentylphenyl)penztriazole VA-6 Ethyl 2 -Cyano-3,31-diphenylacrylate UVA-7 Bis(3,5-di-t-butyl-4-hydroxybenzylphosphoric acid) monoethyl ester N! Salt UVA-8 Bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate Table-1 Example 2 25 thiurethane dove (25 parts polyurethane resin, 3
．． After adding 1 g of the test compound shown in Table 2 to the polyurethane resin (75 parts of dimethylformamide and 71.25 parts of tetrahydrofuran), it was coated on a polyester film to a thickness of 1.2 mm and heated at 45°C. It was dried in a dryer for 1 hour. The sheet thus obtained was punched out using a No. 3 dumbbell and exposed to a fade meter (light source: ultraviolet carponk, black panel temperature: 63 parts, 3°C).
) after 60 hours and 120 hours of light irradiation, a tensile test (
Tensile speed: 200 #Im/min, measurement temperature:
25°C) to determine the breaking strength retention rate.

The results are shown in Table-2.

Table 2 Example 3 The following formulation was melt-kneaded on a mixing reel at 150°C,
A sheet with a thickness of 0.51-1 was produced by hot pressing at 160°C.

This sheet was irradiated for 1200 hours in a sunshine weather meter (light source: carbon arc, black wire temperature: 63±3°C, spray cycle: 120 minutes, spraying time: 18 minutes), and the degree of discoloration was observed. .

The results are shown in Table-3.

<Blend> Polyvinyl chloride 100 parts by weight Dioctyl phthalate 38 epoxidized soybean oil
2 B&-stearate l Zn-stearate 0.3 Test compound
0.2 Table-3

Claims (1)

[Scope of Claims] A stabilized synthetic resin composition comprising a synthetic resin and a compound represented by the following structural formula. (In the formula, R1 represents a hydrogen atom or a methyl group, and R2
represents an alkyl group having 1 to 3 carbon atoms. )