JP2579511B2 - Reinforced polypropylene resin composition - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a polypropylene resin composition reinforced with an inorganic filler. More specifically, the present invention relates to a reinforced polypropylene resin composition having improved thermal stability and metal degradation resistance, which is obtained by mixing an antioxidant, a metal deactivator, an epoxy compound and an inorganic filler with a polypropylene resin.

(Prior art) Polypropylene resin is susceptible to thermal oxidative degradation.
For example, various phenol-based, thio-based or phosphorus-based antioxidants are added. In addition, since the polypropylene resin accelerates its deterioration when it comes into contact with a metal such as copper, various kinds of metal deactivators are further added when it is used for applications that come into contact with copper. On the other hand, a composition obtained by adding an inorganic filler to the polypropylene resin has excellent mechanical strength such as tensile strength, bending strength and rigidity, and is therefore used in various fields as an industrial part.

However, in the case of a composition in which an antioxidant, a metal deactivator and an inorganic filler are added to a polypropylene resin, the antioxidant and the metal deactivator are adsorbed by the inorganic filler, so that the heat of the composition is reduced. Stability and resistance to metal degradation are reduced to near the level of thermal stability and resistance to metal degradation of polypropylene resins without the addition of antioxidants and metal deactivators. For this reason, it is necessary to add a large amount of the antioxidant and the metal deactivator, and even if it is added in a large amount, the thermal stability and the metal deterioration resistance still do not reach a sufficient level. It is a fact.

Therefore, the use of inorganic filler reinforced polypropylene resin is naturally limited at present because automotive parts and electrical parts often use metal contacts such as copper contacts and use in high-temperature atmospheres. Improvements in the thermal stability and metal degradation resistance of inorganic filler reinforced polypropylene resins have been strongly desired.

As a composition with improved thermal stability of inorganic filler reinforced polypropylene resin, polypropylene resin, talc,
A composition comprising an antioxidant and an epoxy compound has been proposed (GB 1,297,802).

However, there is a problem that the above-described composition does not improve the metal deterioration resistance and does not necessarily improve the thermal stability.

(Problems to be Solved by the Invention) The present inventors have intensively studied to improve the thermal stability and metal degradation resistance of a composition obtained by blending an antioxidant, a metal deactivator and an inorganic filler in a polypropylene resin. did. As a result, the inorganic filler, the antioxidant, the metal deactivator, and the epoxy compound are blended with the polypropylene resin to form three additives, the antioxidant, the metal deactivator, and the epoxy compound. It has been found that an inorganic filler reinforced polypropylene resin composition having significantly improved thermal stability and metal degradation resistance due to synergy can be obtained, and the present invention has been completed based on this finding.

As is apparent from the above description, an object of the present invention is to provide an inorganic filler reinforced polypropylene resin composition having significantly improved thermal stability and resistance to metal degradation.

(Means for Solving the Problems) The present invention has the following configurations.

100 parts by weight of polypropylene resin, antioxidant 0.01-5
A reinforced polypropylene resin composition comprising 99 to 30% by weight of an inorganic filler and 1 to 70% by weight of an inorganic filler mixed with 0.01 to 5 parts by weight of a metal deactivator and 0.01 to 10 parts by weight of an epoxy compound.

The polypropylene resin used in the present invention is a crystalline propylene homopolymer, propylene containing propylene as a main component and ethylene or other α-olefins such as butene-1, hexene-1, heptene-1, octene-1 and the like. The above is a crystalline copolymer. The crystalline copolymer may be a crystalline random copolymer or a crystalline block copolymer. Further, a so-called modified polypropylene resin obtained by modifying a polypropylene resin with an unsaturated carboxylic acid or a derivative thereof, or a mixture of the modified polypropylene resin and an unmodified polypropylene resin may be used.

Specific examples of the inorganic filler used in the present invention include talc, mica, clay, calcium carbonate, aluminum hydroxide, magnesium hydroxide, barium sulfate, glass fiber, carbon fiber, silica, calcium silicate, potassium titanate, kaolinite. , Sericite, gypsum and the like, but there is no particular limitation as long as it is an inorganic filler which can be usually added to a polypropylene resin.

The inorganic filler may be of one type or two or more types.

The amount of the inorganic filler is 1 to 70% by weight, preferably 10 to 70% by weight.
~ 50% by weight. If the blending amount is less than 1% by weight, the effect of blending the inorganic filler, that is, tensile strength, bending strength,
Improvement in mechanical strength such as flexural modulus has not been achieved, and
If it exceeds 70% by weight, the impact resistance is undesirably reduced.

The antioxidant used in the present invention is an antioxidant such as a phenol-based antioxidant, a thio-based antioxidant, and a phosphorus-based antioxidant. Not done. The antioxidants can be used alone or in combination of two or more. The most common use case is to combine an antioxidant such as a hindered phenol compound with an antioxidant such as an alkylthiodipropionate (also called a synergist). The antioxidant, whether used alone or in combination, contains one or more phenolic antioxidants.
It is preferable to use more than one kind from the viewpoint of thermal stability.

Specifically, the phenolic antioxidants include 2,6-di-t-butylphenol, 2,6-di-t-butyl-p-cresol, and n-octadecyl-β- (4′-hydroxy -3 ', 5'
-Di-tert-butylphenyl) propionate, 2,4-bis (n-octylthio) -6- (4-hydroxy-3 ', 5'-di-tert-butylanilino) -1,3,5-triazine, styrenated Phenol, 2,2'-methylenebis (4-methyl-6-t-butylphenol), 4,4'-butylidenebis (3-methyl-6-t-butylphenol), N, N'-bis- [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyl] hydrazine, 1,1,3-tris (2-methyl-4-hydroxy-5-t
-Butylphenyl) butane, 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, tris (3,5-di-tert-butyl) 4-hydroxybenzyl) isocyanurate, tetrakis [methylene (3,5-di-t-butyl-4-hydroxyhydrocinnamate)] methane, 1,1,3-tris- (2-methyl-4-hydroxy-5) −
t-butylphenyl) butane; thio-based antioxidants include dilauryl-3,3'-thiodipropionate, dimyristyl-3,3'-thiodipropionate, distearyl-3,3'-thiodiester Propionate, pentaerythritol tetra (β-laurylthiopropionate) ester, 2-mercaptobenzimidazole, Phosphorus-based antioxidants: diphenylisooctyl phosphite, triphenyl phosphite, trisnonyl phenyl phosphite Distearyl pentaerythritol diphosphite, 4,4'-butylidenebis (3-methyl-6-t-butylphenyl-di-tridecylphosphite), tetrakis (2,4-di-t-butylphenyl) -4,4 '-
Biphenylenediphosphonite, trilauryltrithiophosphite, 3,5-di-t-butyl-4-hydroxybenzylphosphonic acid diethyl ester and the like can be mentioned.

The compounding amount of the antioxidant is 0.01 to 5 parts by weight, preferably 0.5 to 3 parts by weight based on 100 parts by weight of the polypropylene resin. If the compounding amount is less than 0.01 part by weight, improvement in thermal stability is not achieved, and if it exceeds 5 parts by weight, the effect of improving thermal stability saturates and is not practical. Not uneconomical.

Known metal deactivators can be used without any limitation. Specific examples of the metal deactivator used in the present invention include bisbenzylidene hydrazide oxalate, m-nitrobenzhydrazide, 3- (N-salicyloyl) amino-1,2,4-triazole, N, N'- Bis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyl] hydrazine, N, N'-bis {2- [3- (3,5-di-t-butyl-4-
Hydroxyphenyl) propionyloxy] ethyldioxamide and the like. The metal deactivator used may be one kind or two or more kinds.

The compounding amount of the metal deactivator is polypropylene resin 100.
It is 0.01 to 5 parts by weight, preferably 0.1 to 3 parts by weight based on parts by weight. If the compounding amount is less than 0.01 part by weight, the effect of improving the metal deterioration resistance is not achieved, and even if it exceeds 5 parts by weight, the above-mentioned improvement effect is saturated, and further improvement is achieved. It is not only practical but also uneconomical.

The epoxy compound used in the present invention is bisphenol A
Type, bisphenol F type, glycidyl ether type epoxy compound such as novolak type, glycidyl ester type epoxy compound such as diglycidyl phthalate,
In addition to glycidylamine-based epoxy compounds such as triglycidyl isocyanurate, linear aliphatic epoxy compounds, alicyclic epoxy compounds and the like can be mentioned. The epoxy compound to be used may be one kind or two or more kinds, but it is particularly preferable to use a bisphenol A type glycidyl ether-based epoxy compound.

The compounding amount of the epoxy compound is 100 polypropylene resin.
It is 0.01 to 10 parts by weight, preferably 0.5 to 5 parts by weight based on parts by weight.

When the compounding amount is less than 0.01 part by weight, the synergistic effect of the three agents when the antioxidant and the metal deactivator are combined is not sufficiently exerted. The effect cannot be expected to be improved, and it is not only practical but also uneconomical.

In the composition of the present invention, additives usually added to the polypropylene resin, for example, a nucleating agent, a light stabilizer, a lubricant, a neutralizing agent, an antistatic agent, a pigment, a flame retardant, and a dispersant such as a metal soap. Alternatively, a peroxide or the like can be used in combination.

The method for producing the composition of the present invention is not particularly limited, and is generally known in the art. For example, a predetermined amount of each component is added to a polypropylene resin in a usual mixing apparatus such as a Hensiel mixer (trade name), a super mixer, a tumbler mixer. It is obtained by mixing using a ribbon blender or a Banbury mixer and melt-kneading at a temperature of 150 to 300 ° C. using a usual single-screw extruder, twin-screw extruder or various kneaders.

(Examples) Hereinafter, the present invention will be described specifically with reference to Examples and Comparative Examples, but the present invention is not limited to the scope.

 The following evaluation method was used.

(1) Thermal stability test (oven life test): Length 50
mm, width 25mm, thickness 1mm test piece was placed in a circulating hot air oven adjusted to a temperature of 150 ° C, and the time until the test piece completely deteriorated (time until the tensile strength became 0) was measured (JIS K
7212).

(2) Metal degradation resistance test: length 50mm, width 25mm, thickness 1m
A 25 m long, 0.3 mm thick copper plate was placed in a circulating hot air oven, which was fixed at a clip and adjusted to a temperature of 150 ° C. Measure the time to penetrate (based on JIS K 7212).

Examples 1-2, Comparative Examples 1-10 Melt flow rate (temperature
Discharge rate of molten resin for 10 minutes when a load of 2.16 kg is applied at 230 ° C) 2.0 g / 10 min powdered polypropylene homopolymer 1
00 parts by weight and predetermined amounts of the components shown in Table 1 described below were placed in a Hensiel mixer (trade name), and mixed by stirring for 3 minutes. The resulting mixture was screwed with a screw diameter of 45 mmφ, L / D
= 30, and the mixture was melt-kneaded at a melt-kneading temperature of 250 ° C. and extruded into pellets. Further, as Comparative Examples 1 to 10, each compounded component was put into a Hensiel mixer (trade name) in the compounding ratios shown in Table 1 below, and the mixture was stirred, mixed, melt-kneaded and extruded according to Examples 1 and 2. It has become.

For the test piece for evaluation, the obtained pellet was used at a resin temperature of 250 ° C.
Prepared by injection molding.

A thermal stability test (oven life test) and a metal deterioration resistance test were performed on the molded test pieces. The results are shown in Table 1.

As can be seen from Table 1, Examples 1 and 2 are examples of the composition of the present invention. Unlike the comparative examples, the thermal stability and the metal deterioration resistance are remarkably excellent at the same time. In Comparative Examples 1 and 6, only the antioxidant was added and the metal deactivator and the epoxy compound were not added, but the thermal stability and the metal deterioration resistance were considerably inferior to those of the examples. The compositions of Comparative Examples 1 and 6 to which a metal deactivator was added were respectively Comparative Examples 2 and
Although it is 7, the thermal stability is hardly changed as compared with Comparative Examples 1 and 6, and the metal deterioration resistance is improved to some extent, but it is at a level far less than that of Examples. Comparative Examples 3 and 8 are a combination system of a metal deactivator and an epoxy compound. However, since no antioxidant was added, the thermal stability and the metal deterioration were not significantly improved. Comparative Examples 4 and 9 are a combination of an antioxidant and an epoxy compound (UK Patent No. 1,29
No. 7,802), although the thermal stability is remarkably improved, it does not reach the level of the examples, and the metal deterioration resistance has not been improved at all. Comparative Example 5 is also a combination system of an antioxidant and an epoxy compound as in Comparative Example 4, but Comparative Example 5 has a larger amount of antioxidant than Comparative Example 4, and has the same thermal stability as that of the Example. It has been improved. But,
The metal deterioration resistance has not yet been improved.

(Effect of the Invention) If any of the antioxidant, the metal deactivator, and the epoxy compound is missing, a composition having significantly improved thermal stability and metal degradation resistance at the same time cannot be obtained.

The reinforced polypropylene resin composition of the present invention has both thermal stability and resistance to metal degradation due to the synergistic action of the three components of an antioxidant, a metal deactivator and an epoxy compound despite the addition of an inorganic filler. Is drastically improved, and can be suitably used for the production of various industrial materials, especially automobile parts, electric product parts and the like.

Claims (3)

(57) [Claims] 1. A composition comprising 100 parts by weight of a polypropylene resin, 0.01 to 5 parts by weight of an antioxidant, 0.01 to 5 parts by weight of a metal deactivator and 0.01 to 10 parts by weight of an epoxy compound.
A reinforced polypropylene resin composition comprising 1 to 70% by weight of an inorganic filler in 30% by weight. 2. The reinforced polypropylene resin composition according to claim 1, wherein the inorganic filler is mica or talc. 3. The reinforced polypropylene resin composition according to claim 1, wherein the antioxidant is a phenolic antioxidant.