JP3175298B2 - Stabilized propylene polymer composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a propylene polymer composition which is excellent in stability during processing and excellent in hue of a molded article.

[0002]

2. Description of the Related Art Polypropylene resin has excellent physical properties.
Due to its chemical and electrical properties, blow molding,
Processed into molded products, pipes, sheets, films, fibers, etc. by various methods such as extrusion molding, injection molding, calendering, etc., and are used in various fields as parts and daily necessities such as automobiles, electric appliances and electronic appliances. . However, the mechanical properties are not always satisfactory, and the heat resistance and scratch resistance are not sufficient. Therefore, various inorganic fillers such as talc, calcium carbonate, wollastonite, and glass beads have been blended with polypropylene resin to improve various properties such as mechanical properties, heat resistance, scratch resistance, and dimensional stability. What has been molded into various shapes is used in various fields.

[0003] However, when a fibrous inorganic filler is used as the inorganic filler, there is a problem that the processing stability is reduced if the processing time is prolonged or stays in the processing machine. Conventionally, for the purpose of solving such a problem of processing stability, distearyl pentaerythritol diphosphite, bis (2,4-di-t-butylphenyl) pentaerythritol diphosphite,
It is known that a phosphorus-based antioxidant such as tris (2,4-di-t-butylphenyl) phosphite is added during extrusion granulation of a polypropylene resin.

[Problems to be solved by the invention]

[0004] By blending such a phosphorus-based antioxidant, the processing stability of the polypropylene resin is improved, but there is a problem that the color of the molded article is reduced when the polypropylene resin stays in the processing machine. .

The present inventors have conducted intensive studies to find a blend of a polypropylene resin which is excellent in stability during processing and also excellent in hue of a molded product, and as a result, the present invention has been achieved.

[0006]

That is, the present invention provides a polypropylene resin comprising (A) a fibrous inorganic filler, (B) a phenolic compound represented by the following general formula (I), and (C) a phenolic compound represented by the following general formula: by blending a phosphorus-based antioxidant represented by (II) Ri Na, the composition ratio of the fibrous inorganic filler, fibrous
Based on the total weight of inorganic filler and polypropylene resin
From 3 to 40% by weight, and the fluorine compound represented by the general formula [I]
Enol compounds are polypropylene resin and fibrous
0.01 to 2 weight per 100 parts by weight of machine filler
Parts, the phosphorus-based antioxidant represented by the general formula (II) is
Total 10 of polypropylene resin and fibrous inorganic filler
And provides a 0.01 propylene-based polymer composition ing with parts compounded by 0 part by weight.

[0007]

Embedded image

(Wherein R ¹ represents hydrogen or methyl;
Alkyl of 1-9 carbon atoms R ² and R ³ are each independently)

[0009]

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(Wherein X represents 2,4-di-t-butylphenyl, 2,6-di-t-butyl-4-methylphenyl or stearyl)

The polypropylene resin referred to in the present invention is a polymer containing propylene as a main monomer component. In addition to a propylene homopolymer, propylene is a main component, and other copolymerizable monomers such as ethylene are used. α
-Random and block copolymers with olefins are included. Particularly, a homopolymer of propylene and a random or block copolymer of propylene and another α-olefin are preferably used. In the case of a copolymer, the copolymerization component other than propylene may be one kind or two or more kinds, but the copolymerization ratio is preferably at most 20% by weight based on the whole monomer. Specific examples of the monomer that can be a copolymerization component, particularly α-olefins other than propylene, include ethylene and C 4-12
Α-olefins, and ethylene and α-olefins having 4 to 8 carbon atoms are particularly preferable. Suitable α
-Examples of the olefin include ethylene, butene-1, heptene-1, 4-methylpentene-1, and hexene-1.

In the present invention, a fibrous inorganic filler, a specific phenolic compound and a specific phosphorus antioxidant are blended with such a polypropylene resin.

Specific examples of suitable fibrous inorganic fillers include potassium titanate fiber, wollastonite, mineral fiber, inorganic gypsum fiber, and milled glass fiber.

These fibrous inorganic fillers preferably have a fiber thickness (hereinafter referred to as "fiber diameter") of about 0.1 to 15 μm. Although it is not impossible to use a fiber having a fiber diameter of less than 0.1 μm, it is generally not only difficult to blend other components, but even if blended, dispersion is often poor. On the other hand, a fiber having a fiber diameter exceeding 15 μm is not unusable, but tends to deteriorate the appearance of a molded article of the obtained composition. Fiber length is 7 ~
About 300 μm is appropriate. The use of a fibrous inorganic filler having a length of less than 7 μm is not sufficient, but the effect of improving the rigidity of the composition is not sufficient, and a filler having a length of more than 300 μm is not used. Is used, the appearance of a molded article of the composition obtained is not good.

The composition ratio of the fibrous inorganic filler is 3 to 40% by weight based on the total weight with the polypropylene resin.
It shall be the degree. If the composition ratio of the fibrous inorganic filler in the whole composition is less than 3% by weight, the effect of improving the composition obtained is not always sufficient. On the other hand, when the composition ratio of the fibrous inorganic filler exceeds 40% by weight, the performance as a polypropylene resin becomes difficult to be sufficiently exhibited.

In the phenolic compound of the general formula [I] used in the present invention, R ¹ is hydrogen or methyl. R ² is an alkyl having 1 to 9 carbon atoms, and among them, an alkyl having 4 to 8 carbon atoms is preferable, and an alkyl bonded to a benzene ring at a quaternary carbon, such as t 2
-Butyl, t-amyl and t-octyl are more preferred. R ^{3 is} also alkyl having 1 to 9 carbons, among which alkyl having 1 to 6 carbons is preferable, and particularly preferable are methyl, ethyl, t-butyl and t-butyl.
-Amyl.

Preferred specific examples of the compound represented by the general formula [I] include the following. 2-tert-butyl-6- (3-tert-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate,
2,4-di-t-butyl-6- [1- (3,5-di-t
-Butyl-2-hydroxyphenyl) ethyl] phenyl acrylate, 2,4-di {t-amyl-6- [1-
(3,5-di-t-amyl-2-hydroxyphenyl)
Ethyl] phenyl acrylate.

In the phosphorus antioxidant of the general formula [II], X is 2,4-di-t-butylphenyl, 2,6-
Di-t-butyl-4-methylphenyl or stearyl. Therefore, the following three compounds are included in the general formula [II].

Bis (2,4-di-t-butylphenyl)
Pentaerythritol diphosphite, bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite, and distearyl pentaerythritol diphosphite.

As described above, it is essential that the phosphorus antioxidant used in the present invention has a pentaerythritol diphosphite skeleton represented by the general formula [II]. When combined with the phenolic compound, the composition exhibits excellent effects in processing stability and hue stability. Incidentally, in addition to the phosphorus-based antioxidant represented by the general formula [II], a phosphorus-based antioxidant having another structure may be used in combination.

The phenolic compound represented by the general formula [I] and the phosphorus-based antioxidant represented by the general formula [II] are each added to a total of 100 parts by weight of the polypropylene resin and the fibrous inorganic filler. 0.01 mixed within a range of parts by weight. When the amount is less than 0.01 part by weight, the effects intended in the present invention are hardly sufficiently exhibited, and even if the amount is more than 2 parts by weight, the effect corresponding to the amount cannot be obtained. Economically disadvantaged.

In the present invention, if necessary, other additives such as other phenolic antioxidants, sulfur antioxidants, ultraviolet absorbers, hindered amine light stabilizers, lubricants, pigments, plasticizers, Flame retardants, antistatic agents, flame retardants, inorganic fillers and the like may be blended. Specific examples of these additives that can be used together are listed below.

Examples of the phenolic antioxidant include the following.

N-octadecyl 3- (3,5-di-t-
Butyl-4-hydroxyphenyl) propionate, pentaerythrityl tetrakis [3- (3,5-di-t
-Butyl-4-hydroxyphenyl) propionate], triethylene glycol bis [3- (3-t-
Butyl-4-hydroxy-5-methylphenyl) propionate], 3,9-bis [2- {3- (3-t-butyl-4-hydroxy-5-methylphenyl) propionyloxy} -1,1-dimethyl Ethyl] -2, 4, 8,
10-tetraoxaspiro [5.5] undecane, 1,
3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, tris (4-t-butyl-3-hydroxy-2,6-dimethylbenzyl) Isocyanurate, 2,4-bis (n
-Octylthio) -6- (3,5-di-t-butyl-4
-Hydroxyanilino) -1,3,5-triazine, tris (3,5-di-t-butyl-4-hydroxybenzyl) isocyanurate, 2,2'-ethylidenebis (4,6-di-t- Butylphenol).

Examples of the sulfur-based antioxidant include the following.

Pentaerythrityl tetrakis (3-laurylthiopropionate), dilauryl 3,3'-
Thiodipropionate, dimyristyl 3,3'-thiodipropionate, distearyl 3,3'-thiodipropionate.

Examples of the ultraviolet absorber include the following.

2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octyloxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, bis (5-benzoyl-4-hydroxy-2-
Methoxyphenyl) methane, 2,2 ', 4,4'-tetrahydroxybenzophenone,

2- (2-hydroxy-5-methylphenyl) benzotriazole, 2- [2-hydroxy-3-
(3,4,5,6-tetrahydrophthalimidomethyl)
-5-methylphenyl] benzotriazole, 2- (3
-T-butyl-2-hydroxy-5-methylphenyl)
-5-chlorobenzotriazole, 2- (3,5-di-
t-butyl-2-hydroxyphenyl) benzotriazole, 2- (2-hydroxy-5-t-octylphenyl) benzotriazole, 2- (3,5-di-t-amyl-2-hydroxyphenyl) benzotriazole, 2
-[2-hydroxy-3,5-bis (α, α-dimethylbenzyl) phenyl] -2H-benzotriazole, 2-
(3,5-di-t-butyl-2-hydroxyphenyl)
-5-chlorobenzotriazole,

2,2'-methylenebis [6- (2H-benzotriazol-2-yl) -4- (1,1,3,3
-Tetramethylbutyl) phenol], poly (3-1)
1) (Ethylene glycol) and methyl 3- [3-
Condensation product with (2H-benzotriazol-2-yl) -5-t-butyl-4-hydroxyphenyl] propionate, 2-ethylhexyl 3- [3-t-butyl-5
-(5-chloro-2H-benzotriazol-2-yl) -4-hydroxyphenyl] propionate, octyl 3- [3-t-butyl-5- (5-chloro-2H
-Benzotriazol-2-yl) -4-hydroxyphenyl] propionate, methyl 3- [3-tert-butyl-5- (5-chloro-2H-benzotriazole-2)
-Yl) -4-hydroxyphenyl] propionate,
3- [3-t-butyl-5- (5-chloro-2H-benzotriazol-2-yl) -4-hydroxyphenyl] propionic acid, 2,2'-methylenebis [4-t-
Butyl-6- (2H-benzotriazol-2-yl)
Phenol].

Examples of the hindered amine light stabilizer include the following.

Bis (2,2,6,6-tetramethyl-4
-Piperidyl) sebacate, dimethyl succinate and 1- (2-hydroxyethyl) -4-hydroxy-
Polycondensate with 2,2,6,6-tetramethylpiperidine, poly [(6-morpholino-1,3,5-triazine-
2,4-diyl) {(2,2,6,6-tetramethyl-
4-piperidyl) imino {hexamethylene} (2,2
6,6-tetramethyl-4-piperidyl) imino}],
Bis (1,2,2,6,6-pentamethyl-4-piperidyl) 2- (3,5-di-t-butyl-4-hydroxybenzyl) -2-butylmalonate, 4- [3-
(3,5-di-t-butyl-4-hydroxyphenyl)
Propionyloxy] -1- [2- {3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyloxy} ethyl] -2,2,6,6-tetramethylpiperidine, bis (1, 2,2,6,6-pentamethyl-4
-Piperidyl) decanedioate, tetrakis (2,
2,6,6-tetramethyl-4-piperidyl) 1,
2,3,4-butanetetracarboxylate, poly [{6- (1,1,3,3-tetramethylbutyl) imino-1,3,5-triazine-2,4-diyl}
｛(2,2,6,6-tetramethyl-4-piperidyl)
Imino {hexamethylene} (2,2,6,6-tetramethyl-4-piperidyl) imino}],

Mixed ester of 1,2,3,4-butanetetracarboxylic acid with 1,2,2,6,6-pentamethyl-4-piperidinol and 1-tridecanol, 1,2,3,4-butane Tetracarboxylic acid and 2,
Mixed esterified product with 2,6,6-tetramethyl-4-piperidinol and 1-tridecanol, 1,2,2
3,4-butanetetracarboxylic acid and 1,2,2,6
6-pentamethyl-4-piperidinol and 3,9-
Bis (2-hydroxy-1,1-dimethylethyl)-
Mixed esterified product with 2,4,8,10-tetraoxaspiro [5.5] undecane, 1,2,3,4-butanetetracarboxylic acid and 2,2,6,6-tetramethyl-
A mixed ester of 4-piperidinol and 3,9-bis (2-hydroxy-1,1-dimethylethyl) -2,4,8,10-tetraoxaspiro [5.5] undecane;

N, N'-bis (2,2,6,6-tetramethyl-4-piperidyl) hexamethylenediamine
Polycondensation product with 1,2-dibromoethane, 2-methyl-2
-(2,2,6,6-tetramethyl-4-piperidyl)
Amino-N- (2,2,6,6-tetramethyl-4-piperidyl) propionamide, N, N ', 4,7-tetrakis [4,6-bis {N-butyl-N- (2,2 ,
6,6-tetramethyl-4-piperidyl) amino}-
1,3,5-triazin-2-yl] -4,7-diazadecane-1,10-diamine, N, N ', 4-tris [4,6-bis {N-butyl-N- (2,2 , 6,6-
Tetramethyl-4-piperidyl) amino} -1,3,5-
Triazin-2-yl] -4,7-diazadecane-1,
10-diamine, bis (1-acryloyl-2,2,
6,6-tetramethyl-4-piperidyl) 2,2-bis (3,5-di-t-butyl-4-hydroxybenzyl)
Malonate, N, N ', 4,7-tetrakis [4,6-
Bis {N-butyl-N- (1,2,2,6,6-pentamethyl-4-piperidyl) amino} -1,3,5-triazin-2-yl] -4,7-diazadecane-1,10
-Diamine, N, N ', 4-tris [4,6-bis {N
-Butyl-N- (1,2,2,6,6-pentamethyl-
4-piperidyl) amino} -1,3,5-triazine-
2-yl] -4,7-diazadecane-1,10-diamine, bis (2,2,6,6-tetramethyl-4-piperidyl) succinate, 2,2,6,6-tetramethyl-4-piperidyl Methacrylate, 1,2,2,6
6-pentamethyl-4-piperidyl methacrylate,
Tetrakis (1,2,2,6,6-pentamethyl-4-
Piperidyl) 1,2,3,4-butanetetracarboxylate.

[0035]

Next, the present invention will be described in more detail by way of examples, but the present invention is not limited to these examples. The percentages in the examples are based on weight unless otherwise specified. The test stabilizers used in the examples are as shown in the following table, and are indicated by respective symbols.

[0036]

Table 1 I-1: 2,4-di-t-amyl-6- [1-
(3,5-di-t-amyl-2-hydroxyphenyl)
Ethyl] phenyl acrylate I-2: 2-t-butyl-6- (3-t-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate P-1: bis (2,4-di- t-butylphenyl) pentaerythritol diphosphite P-2: bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite P-3: distearyl pentaerythritol diphosphite P-4 : Tris (2,4-di-t-butylphenyl) phosphite AO-1: pentaerythrityl tetrakis (3-laurylthiopropionate) AO-2: distearyl 3,3'-thiodipropionate

Example 1: Unstabilized polypropylene resin 8
0 parts by weight, as a fibrous inorganic filler, the fiber diameter is 0.2 to 0.2
0.5 μm, 20 parts by weight of potassium titanate whiskers having an average fiber length of 10 to 20 μm, and the test stabilizer were blended in the proportions shown in Tables 2 and 3, and mixed with a Henschel mixer. The mixture was kneaded with a screw extruder and pelletized. In Tables 2 and 3, the amount of the test stabilizer is shown as a ratio to the total weight of the polypropylene resin and the potassium titanate whisker.

The obtained pellets were put into a melt indexer (manufactured by Takara Kogyo Co., Ltd.), and the fluidity (melt flow rate: g / 10 minutes) after staying at 280 ° C. for 30 minutes was measured. The sex was evaluated. Polypropylene causes molecular chains to be cut by heat and increases fluidity, so that a lower melt flow rate means better heat processing stability. The results are shown in Tables 2 and 3.

On the other hand, the above pellets were retained at 270 ° C. for 30 minutes using a 5.5 oz injection molding machine and then molded to prepare a test piece of 60 × 120 × 3 mm. Was observed. A sample having a good hue, that is, a uniform white test piece was obtained, and a sample was colored or a sample having a non-uniform hue was evaluated as Δ. The results are shown in Tables 2 and 3.

[0040]

[Table 2]

[0041]

[Table 3]

[0042]

According to the present invention, a propylene-based polymer composition comprising a polypropylene resin and a fibrous inorganic filler and further a specific phenolic compound and a specific phosphorus-based antioxidant is blended. While maintaining various properties such as mechanical properties, heat resistance, scratch resistance, and dimensional stability due to the blending of the inorganic filler, it is possible to prevent a decrease in the hue of the molded article. Therefore, the propylene-based polymer composition of the present invention is excellent in stability at the time of processing and hue of a molded product, and exhibits excellent effects not seen in conventional products.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-153241 (JP, A) JP-A-2-225544 (JP, A) JP-A-2-228345 (JP, A) JP-A-63-1988 142049 (JP, A) JP-A 64-2499 (JP, A) JP-A 1-259049 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08L 23/10 C08K 5 / 13-5/527 C08K 7/04

Claims (6)

(57) [Claims] 1. A polypropylene resin comprising: (A) a fibrous inorganic filler; and (B) the following general formula [I]: (Wherein R ¹ represents hydrogen or methyl; R ² and R ³
Each independently represents an alkyl having 1 to 9 carbon atoms), and (C) a phenolic compound represented by the following general formula [II]: (Wherein X is 2,4-di-t-butylphenyl, 2,6
-Di-t-butyl-4-methylphenyl or stearyl).
Ri, the composition ratio of the fibrous inorganic filler, a fibrous inorganic filler port
3 to 40 weights based on the total weight with the propylene resin
% Of the phenolic compound represented by the general formula [I]
Total 100 parts by weight of pyrene resin and fibrous inorganic filler
0.01 to 2 parts by weight based on the weight of the phosphorus-containing antioxidant represented by the general formula [II].
To 100 parts by weight of the total of the resin and the fibrous inorganic filler
Propylene-based polymer composition ing by blending 0.01 to 2 parts by weight against. 2. The method according to claim 1, wherein the polypropylene resin is a homopolymer of propylene or propylene and 20% by weight or less of another α-polymer.
The composition according to claim 1, which is a copolymer with an olefin. 3. The composition according to claim 1, wherein the fibrous inorganic filler is potassium titanate fiber, wollastonite, mineral fiber, inorganic gypsum fiber or milled glass fiber. 4. A fibrous inorganic filler having a fiber diameter of 0.1 to 15 μm.
m and a fiber length of 7 to 300 μm.
The composition according to any one of the above. 5. In the general formula [I] representing a phenolic compound, R ² is alkyl having 4 to 8 carbon atoms bonded to a benzene ring at a quaternary carbon, and R ³ is alkyl having 1 to 6 carbon atoms. The composition according to any one of claims 1 to 4. 6. The phenolic compound is 2-t-butyl-6- (3-t-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate,
2,4-di-t-butyl-6- [1- (3,5-di-t
-Butyl-2-hydroxyphenyl) ethyl] phenyl acrylate or 2,4-di (t-amyl-6)
The composition according to claim 5, which is-[1- (3,5-di-t-amyl-2-hydroxyphenyl) ethyl] phenyl acrylate.