JPH09194643A - Ethylene resin composition having excellent hot water resistance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an ethylene resin having an excellent hot water resistance by using a condensate of a particular ethylenediamine deriv. with a triazine deriv. as an antioxidant in combination with a phenolic antioxidant in an ethylene resin. SOLUTION: A condensate (B) of N,N'-bis(3-aminopropyl)ethylenediamine with 2,4-bis[N-butyl-N-1,2,2,6,6-pentamethyl-4-piperidyl)amino]-6-chloro-1, 3,5- triazine and a phenolic antioxidant (C) are incorporated into an ethylene resin (A) to prepare a resin compsn. The content of the component (B) is 0.01 to 2wt.%, and the content of the component (C) is 0.01 to 2wt.%. The component (A) may be an ethylene homo- or copolymer which may be prepd. by any of high-pressure, medium-pressure, and low-pressure methods. In particular, however, a linear low-density polyethylene prepd. by the medium- or low-pressure method can offer a large effect. Examples of the component (c) include octadecyl 3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate. The above incorporation serves to prevent the ethylene resin from being deteriorated by hot water.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ethylene resin composition containing a specific combined antioxidant, which is suppressed in thermal deterioration due to hot water and has excellent hot water stability.

[0002]

2. Description of the Related Art Conventionally, polyethylene has been processed by injection molding, extrusion molding, compression molding, etc. by taking advantage of its excellent moldability, mechanical properties, chemical resistance, etc., and injection products, pipes, sheets, blow products, steel pipes. It is used in a wide range of applications as a corrosion-resistant coating for cables and cables, and is also used in a wide range of usage environments. Especially linear low density polyethylene
Mechanical properties such as tensile strength, impact strength, rigidity, stress crack resistance, etc. are superior to conventional high density polyethylene,
Optical properties such as transparency, haze, and gloss are equivalent to those of high-pressure low-density polyethylene.

However, as the environment of use becomes wider, water-contact pipes and anti-corrosion coatings for marine buried pipelines that transport high-temperature liquids, such as corrosion-resistant coatings, are exposed to water, especially in high-temperature environments. In the case of contact or direct contact with hot water, the linear low-density polyethylene has low crystallinity, and thus the antioxidant previously added to the resin is eluted, There has been a problem that polyethylene does not exhibit an antioxidant effect and polyethylene deteriorates at an early stage, and its excellent characteristics cannot be maintained.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to improve the drawbacks of the prior art and to provide an ethylene resin having excellent hot water stability.

[0005]

Means for Solving the Problems The inventors of the present invention have made earnest studies to solve the above problems, and as a result, the above objects can be achieved by incorporating a specific antioxidant into an ethylene resin. The present invention has been completed by finding

That is, according to the present invention, N, N'-bis (3
-Aminopropyl) ethylenediamine-2,4-bis [N-butyl-N- (1,2,2,6,6-pentamethyl-4-piperidyl) amino] -6-chloro-1,3
An ethylene resin composition comprising a 5-triazine condensate and a phenolic antioxidant.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The ethylene resin used in the present invention is a homopolymer of ethylene or a copolymer of ethylene containing ethylene as a main component and another polymerizable monomer. It may be produced by any of the low pressure method and the polymerization method. Here, as the polymerizable monomer, α-olefin (propylene, butene, pentene, hexene, octene, decene, 3-methylbutene, 4-methylpentene, etc.), unsaturated carboxylic acid or its derivative (acrylic acid,
Methyl acrylate, ethyl acrylate, maleic anhydride, etc.), vinyl ester (vinyl acetate, vinyl butyrate, etc.),
Examples of the copolymer include unsaturated aromatic monomers (styrene, α-methylstyrene, etc.), and the copolymer may be any of copolymerization forms such as block, random, and graft.

In particular, linear low density polyethylene, which is a copolymer of ethylene as a main component and other α-olefins produced by the medium pressure method or low pressure method, is a low density polyethylene produced by a conventional high pressure method. Unlike the above, it is produced using a Ziegler type catalyst or Phillips type catalyst used in the production of medium- and low-pressure method high-density polyethylene, but in the present invention, the mechanical properties and optical properties are excellent, and the effect of the invention is greatly exerted. It is preferable because Linear low-density polyethylene has a structure in which conventional high-density polyethylene has a short branch structure due to the copolymerization component, and the short branch structure is used (that is, the type and content of the copolymerization component are adjusted) to increase the density. suitably reduced is allowed 0.90~0.94g / cm ^3, preferably about be one obtained by the order of 0.91~0.93g / cm ^3, there is more linear with conventional high-pressure low-density polyethylene, It is a polyethylene with more branches than medium- and low-pressure high-density polyethylene. This linear low-density polyethylene is produced by applying a production process of a gas phase polymerization method using a fluidized bed reactor, a stirred bed reactor, a tubular reactor, etc.
It can be manufactured based on the method (gas phase polymerization method using a fluidized bed reactor) described in JP-A No. 4-148093, JP-A-54-154488 and the like.

Further, N, N'-bis (3-aminopropyl) ethylenediamine.2,4-bis [N-butyl-N- (1,2,2,6,6-pentamethyl-4) used in the present invention is used. -Piperidyl) amino] -6-chloro-1,
The amount of the 3,5-triazine condensate compounded is generally 0.01.
˜2 wt%, especially 0.05 to 1 wt%. If this amount is too small, the effect of hot water stability will not be obtained, while if it is too large, the effect will be saturated and uneconomical.

Further, examples of the phenolic antioxidant used in the present invention include octadecyl-3- (3,5)
-Di-t-butyl-4-hydroxyphenyl) propionate, pentaerythrityl-tetrakis [3- (3,3
5-di-t-butyl-4-hydroxyphenyl) propionate], 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, 1 , 3,5-Tris (4-t-butyl-
3-Hydroxy-2,6-dimethylbenzyl) isocyanuric acid, 3,9-bis [2- {3- (3-t-butyl-
4-Hydroxy-5-methylphenyl) -propionyloxy} -1,1-dimethylethyl] -2,4,8,1
Examples thereof include 0-tetraoxaspiro [5.5] andecan. The compounding amount of the phenolic antioxidant is
Generally, 0.01 to 2% by weight, particularly 0.05 to 1% by weight are suitable. If this amount is too small, the effect of hot water stability will not be obtained, while if it is too large, the effect will be saturated and uneconomical.

In the present invention, in addition to the above-mentioned essential components, if desired, optional components can be added within a range that does not significantly impair the effects of the present invention. As the optional components, for example, other antioxidants, heat stabilizers, ultraviolet absorbers,
There are commonly known additives such as a light stabilizer, a filler, a flame retardant, a pigment, a lubricant, a neutralizing agent, a rust preventive, a conductive agent and an antistatic agent. In particular, it is preferable to add 0.01 to 2% by weight of a sulfur-based antioxidant, a phosphorus-based antioxidant or the like as another antioxidant, but the thioether-based antioxidant is the above-mentioned N, N'- Bis (3-aminopropyl) ethylenediamine ・ 2,4-bis [N-butyl-N- (1,
It should not be added because it has an antagonistic effect with the 2,2,6,6-pentamethyl-4-piperidyl) amino] -6-chloro-1,3,5-triazine condensate. Further, it is suitable to add 0.1 to 3% by weight, especially 0.5 to 2.5% by weight, of carbon black as an ultraviolet ray inhibitor. It is also possible to add 0.01 to 0.2% by weight of metal soaps or a neutralizing agent as a lubricant.

An ethylene resin composition can be obtained by blending the above-mentioned essential components and optionally optional components, and mixing and kneading with a suitable ordinary mixing and kneading machine.
Preferably, it is made into pellets to obtain a molding material.

[0013]

The present invention will be further described below with reference to specific examples. Example 1 Linear low density polyethylene 1 having a melt index (MI) of 0.64 g / 10 minutes and a density of 0.922 g / cm ^3.
With respect to 00% by weight, N, N'-bis (3-aminopropyl) ethylenediamine.2-, 4-bis [N-butyl-N
0.2% by weight of-(1,2,2,6,6-pentamethyl-4-piperidyl) amino] -6-chloro-1,3,5-triazine condensate, and pentaerythrityl-tetrakis [3- ( 3,5-di-t-butyl-4-hydroxyphenyl) propionate] 0.2 wt% was added, and 40
It was put into a mmφ extruder and melt-kneaded at 240 ° C. to obtain pellets. The resin composition pellets were thermocompressed at 190 ° C. to form a 60 mm thick press sheet, and the obtained press sheet was immersed in hot water at 97 ° C. for 30 days.
The oxidation induction period (OIP) of the hot water-treated press sheet and that of the hot water-free press sheet were measured at 200 ° C. Table 1 shows the results.

The oxidation induction period (OIP) was measured by the following method. That is, 10 mg of sample
Samples are taken and heated from room temperature to 200 ° C. in a nitrogen atmosphere with a differential scanning calorimeter (DSC). After the temperature stabilizes at 200 ° C., the inflow gas is switched to oxygen and the state is maintained until the exothermic peak appears. The time from oxygen switching to the offset point of the exothermic peak is defined as the oxidation induction period (OIP). It is generally considered that the larger the oxidation induction period (OIP), the better the resistance to oxidative deterioration.

Example 2 In Example 1, 1,3,5-trimethyl-2,3,5-trimethyl-2,4-trikis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] was used instead of pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate]. 4,6-Tris (3,5-di-t-butyl-
Table 1 shows the results of evaluation performed in the same manner as in Example 1 except that 4-hydroxybenzyl) benzene was used.

Example 3 In Example 2, 1,3,5-trimethyl-2,4
Table 1 shows the results of evaluation performed in the same manner as in Example 2 except that the compounding amount of 6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene was 0.1% by weight.

Comparative Example 1 In Example 3, N, N'-bis (3-aminopropyl) ethylenediamine.2,4-bis [N-butyl-N]
-(1,2,2,6,6-pentamethyl-4-piperidyl) amino] -6-chloro-1,3,5-triazine instead of a poly [{6- (1,1,3,3 -Tetramethylbutyl) amino-1,3,5-triazine-2,
4-diyl} (2,2,6,6-tetramethyl-4-
Piperidyl) imino {hexamethylene} (2,2,6)
6-tetramethyl-4-piperidyl) imino}] was used, and the evaluation results are shown in Table 1 in the same manner as in Example 3.

Comparative Example 2 Linear low density polyethylene 10 used in Example 1
Pentaerythrityl-tetrakis [3
-(3,5-di-t-butyl-4-hydroxyphenyl) propionate] 0.1% by weight, and dimethyl succinate 1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6 Table 1 shows the results of evaluation of a mixture of 0.1% by weight of tetramethylpiperidine polycondensate in the same manner as in Example 1.

Example 4 Linear low density polyethylene 10 used in Example 1
Pentaerythrityl-tetrakis [3
-(3,5-Di-t-butyl-4-hydroxyphenyl) propionate] 0.1% by weight, N, N'-bis (3-aminopropyl) ethylenediamine-2,4-bis [N-butyl-N] -(1,2,2,6,6-pentamethyl-4-piperidyl) amino] -6-chloro-1,
0.1% by weight of 3,5-triazine condensate and average particle size 3
Table 1 shows the results of evaluation of the composition containing 1.5% by weight of 0 nm carbon black in the same manner as in Example 1.

Example 5 Linear low density polyethylene 10 used in Example 1
Pentaerythrityl-tetrakis [3
-(3,5-di-t-butyl-4-hydroxyphenyl) propionate] 0.2% by weight, N, N'-bis (3-aminopropyl) ethylenediamine-2,4-bis [N-butyl-N] -(1,2,2,6,6-pentamethyl-4-piperidyl) amino] -6-chloro-1,
0.2% by weight of 3,5-triazine condensate and average particle size 3
Table 1 shows the results of evaluation of the composition containing 1.5% by weight of 0 nm carbon black in the same manner as in Example 1.

Example 6 Linear low density polyethylene 10 used in Example 1
0,3 wt% 1,3,5-trimethyl-2,4,6
-Tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene 0.1% by weight, N, N'-bis (3-
Aminopropyl) ethylenediamine-2,4-bis [N
-Butyl-N- (1,2,2,6,6-pentamethyl-
4-Piperidyl) amino] -6-chloro-1,3,5-
Table 1 shows the results of evaluation of a mixture of 0.1% by weight of a triazine condensate and 1.5% by weight of carbon black having an average particle size of 30 nm in the same manner as in Example 1.

Comparative Example 3 Linear low density polyethylene 10 used in Example 1
Pentaerythrityl-tetrakis [3
0.1% by weight of (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 0.08% by weight of dilaurylthiodipropionate and 1.5% by weight of carbon black having an average particle diameter of 30 nm. Table 1 shows the results of evaluating the blended materials in the same manner as in the method of Example 1.

Comparative Example 4 Linear low density polyethylene 10 used in Example 1
0,3 wt% 1,3,5-trimethyl-2,4,6
-Tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene 0.2% by weight, poly [{6- (1,
1,3,3-tetramethylbutyl) amino-1,3,5
-Triazine-2,4-diyl} (2,2,6,6-
0.2% by weight of tetramethyl-4-piperidyl) imino} hexamethylene {(2,2,6,6-tetramethyl-4-piperidyl) imino}] and 1.5% by weight of carbon black having an average particle size of 30 nm. Table 1 shows the results of evaluating the blended materials in the same manner as in the method of Example 1.

Comparative Example 5 Linear low density polyethylene 10 used in Example 1
4,4'-thiobis (3-methyl-6) relative to 0% by weight
-T-butylphenol) and 0.3% by weight of carbon black and 1.5% by weight of carbon black having an average particle size of 30 nm were blended and evaluated in the same manner as in Example 1.
Shown in

[0025]

[Table 1]

[0026]

EFFECTS OF THE INVENTION According to the present invention, the remarkable effect is obtained that the thermal deterioration of ethylene resin due to hot water is suppressed and an ethylene resin composition having excellent hot water stability is obtained.

Claims (4)

[Claims] 1. N, N'-bis (3-aminopropyl) ethylenediamine.2-, 4-bis [N-butyl-N-
Ethylene resin composition containing (1,2,2,6,6-pentamethyl-4-piperidyl) amino] -6-chloro-1,3,5-triazine condensate and a phenolic antioxidant Stuff. 2. N, N'-bis (3-aminopropyl) ethylenediamine.2,4-bis [N-butyl-N-
The content of (1,2,2,6,6-pentamethyl-4-piperidyl) amino] -6-chloro-1,3,5-triazine condensate is 0.01 to 2% by weight, and the phenol-based oxidation is The ethylene resin composition according to claim 1, wherein the content of the inhibitor is 0.01 to 2% by weight. 3. The ethylene resin has a density of 0.90 to 0.94 g.
The ethylene resin composition according to claim 1, which is a linear low density polyethylene having a linear density of 1 / cm ³ . 4. Further, 0.1 to 3% by weight of carbon black.
The ethylene resin composition according to claim 1, which comprises: