JPH03752A - Polypropylene resin composition - Google Patents

Abstract

PURPOSE:To improve mechanical properties, solid-phase adhesive properties and heat stability under a severe condition by compounding a phenolic antioxidant and a sulfur antioxidant in a compsn. comprising PP, a styrenic resin and a compatibilizer. CONSTITUTION:A compsn. is obtd. by compounding a PP (A) with an MI of 5-60g/10min, a styrenic polymer (B) with an MI of 0.5-20g/10min and a compatibilizer (C) (e.g. styrene-butadiene-styrene block copolymer) in such a way that the content of component C is 10-30 pts.wt. based on 100 pts.wt. sum of the components A and B and the ratio of the sum of the components B and C to the sum of the components A-C is 0.1-0.6. 0.05-0.4 pt.wt. phenolic antioxidant (D) [e.g. tris-(3,5-di-t-butyl-4-hydroxybenzyl)-isocyanurate] based on 100 pts.wt. sum of the components A and B and 0.1-0.6 pt.wt. sulfur antioxidant (E) (e.g. distearyl-3,3'-thiodipropionate) based on 100 pts.wt. sum of the components A and B are compounded in this compsn.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a polypropylene resin composition useful in various industries, particularly in the automobile field, and more specifically, it relates to a polypropylene resin composition that has sufficient mechanical properties such as heat resistance, rigidity, and impact strength. The present invention also relates to a polypropylene resin composition that enables solid phase adhesion and has good thermal stability under severe conditions.

[Prior Art and Problems to be Solved by the Invention] Polypropylene resin has excellent mechanical strength, moldability, chemical resistance, etc., and is widely used in many industrial fields. However, since it is non-polar, it has difficulty in secondary processability, particularly in adhesion in a solid state, and improvements in this respect are strongly desired in various fields. As an improvement method, a method of blending a polymer with good adhesiveness with polypropylene resin (Japanese Unexamined Patent Publication No. 48
-43441, Japanese Patent Publication No. 51-8134), but although this method shows some degree of adhesion, it has poor compatibility, resulting in a significant decrease in physical properties, etc., and also causes layer delamination of the molded product. It had drawbacks and could not be put to practical use. In addition, a method of using polystyrene resin and elastomer together (JP-A-58-104978, JP-A No. 5B-383)
No. 38, No. 52-141854, Special Publication No. 52-170
No. 55) has also been proposed, but the products obtained by these methods have significantly reduced fluidity, heat resistance, and rigidity, and are insufficient for use as industrial materials.

The present inventor collaborated with other inventors to study a polypropylene resin composition with excellent mechanical properties and solid phase adhesion, and found that the polypropylene resin has a specific particle size,
It has already been proposed that a desired resin composition can be obtained by dispersing a styrene resin whose surface is coated with a compatibilizing agent to a specific thickness (Japanese Patent Laid-Open No. 64-8764).
5).

However, this composition did not have sufficient thermal stability under severe conditions.

[Means for Solving the Problems] Therefore, as a result of further research, the present inventors added a specific amount of phenolic oxidation agent to a composition formed by blending polypropylene, a styrene resin, and a compatibilizer in a specific ratio. The present invention was completed based on the discovery that a resin composition with excellent thermal stability under even harsher conditions can be obtained by combining an inhibitor and a sulfur-based antioxidant.

That is, the present invention comprises (A) polypropylene and (B)
10 to 30 parts by weight of the compatibilizer (C) is blended with a total of 100 parts by weight of the styrene resin, and the (A)
) component, the ratio of the total amount of the (B) component and (C) component to the total amount of the (B) component and (C) component is 0.2 to 0.
．． 6, based on a total of 100 parts by weight of components (A) and (B), (D) 0.05 to 0.4 parts by weight of a phenolic antioxidant, and (E) sulfur. The present invention provides a polypropylene resin composition containing 0.1 to 0.6 parts by weight of antioxidants.

The polypropylene used as component (A) in the present invention is not particularly limited as long as it is a crystalline polymer polymerized with propylene monomer as the main component, and may contain comonomers such as ethylene, butene, and 2-methylpentene-1. I don't mind if you stay.

In addition, the melt index of the polypropylene used is 5
~60g710 minutes is preferred. If the melt index is less than 5g710 minutes, moldability will be poor and
If it is 0 g for 710 minutes or more, the impact strength tends to decrease, which is not preferable.

Next, the styrene resin used as component CB) in the present invention may be any resin obtained by homopolymerizing or copolymerizing a styrene monomer, and comonomers include α-methylstyrene, acrylonitrile, maleic anhydride, and methyl methacrylate. It may contain copolymerizable monomers such as. Further, high impact polystyrene reinforced by blending polybutadiene, styrene-butadiene copolymer rubber, etc. can also be used. The melt index of the styrene resin is preferably about 0.5 to 20 g and 710 minutes.

In the present invention, the styrene resin which is the component (B) is dispersed as dispersed particles in the polypropylene which is the component (^), and the surface of the styrene resin dispersed particles (
A compatibilizing agent (component (C) to be described later) is present at the interface with polypropylene to uniformly disperse the styrene resin in the polypropylene and promote compatibilization of the polypropylene and the styrene resin.

Examples of such compatibilizing agent (C) include styrene thermoplastic elastomers such as styrene-butadiene copolymer, styrene-dityrene-butylene copolymer, styrene-isoprene copolymer, acrylic thermoplastic elastomer, and ethylene/ethyl acrylate. /maleic anhydride copolymer, etc. can be used.

The above (^) component, (B) component and (C) in the present invention
) The blending ratio of the components is as follows.

First, the total of components (A) and (B) is 100! 10 to 30 parts by weight, preferably 12 parts by weight of component (C)
It is blended in a proportion of ~25 parts by weight. If the amount of component (C) is less than 10 parts by weight, impact resistance will deteriorate, which is undesirable.On the other hand, if the amount of component (C) exceeds 301 parts by weight, rigidity and heat resistance will deteriorate. Undesirable.

Further, the ratio of the total amount of component (B) and component (C) to the total amount of component (A), component (B), and component (C) is 0.1-0.6, preferably 0.15-0. Blend so that it becomes .55.

Here, when the above ratio is less than 0.1, it is surface hardness.

This is not preferable because the rigidity and adhesiveness become insufficient.

On the other hand, if the ratio exceeds 0.6, heat resistance deteriorates, which is not preferable.

The polypropylene resin composition of the present invention comprises the above (A) to (
It is formed by blending (D) a phenolic antioxidant and (E) a sulfur antioxidant in a composition consisting of component C).

Here, the phenolic antioxidant which is component (D) is not particularly limited, and general phenolic antioxidants can be used. For example, dialkylphenol, trialkylphenol, diphenylmonoalkoxyphenol,
Tetraalkylphenol and the like are used.

To be more specific, dialkylphenols include 2,2-'-methylenebis(6-butyl-4-methylphenol); 1,1-bis(5-t-butyl-4-hydroxy- 2-methylphenyl)butane;
2,2'-methylenebis(4-methyl-6-cyclohexylfuenol), 4,4'-thiobis(6-t-
butyl-3-methylphenol): 2,2-bis(5-
t-butyl-4-hydroxy-2-methylphenyl)-
Examples include 4-n-dodecylmercapto-butane.

Next, as trialkylphenol, 2.6-di-t-
Butyl-4-methylphenol; 2,2'-methylenebis-(6-t-butyl-4-ethylphenol); 2
,2'-methylenebis[4-methyl-6-(α-methylcyclohexyl)phenol];2.2'-methylenebis-(4-methyl-6-tunylphenol): 1
, 1.3-tris-(5-t-butyl-4-hydroxy-2-methylphenyl)butane; ethylene glycol-
Bis-[3,3-bis(3-t-butyl-4-hydroxyphenyl)butyrate]: 1-1-bis-(3,5-
dimethyl-2-hydroxyphenyl)-3-(n-dodecylthio)-butane; 1,3.5-tris-(3,
5-di-t-butyl-4-hydroxybenzyl) -2
,4,6-drimethylbenzene;2,2-bis-(3,
5-di-t-butyl-4-hydroxybenzyl) malonic acid dioctadecyl ester; n-octadecyl-3-(
4-hydroxy-3,5-di-t-butylphenyl)propionate; tetrakis[methylene(3,5-di-t-butylphenyl)propionate;
-butyl-4-hydroxyhydrocinnamate)]]
Methane: 3.9-bis1.1-di-methyl-2-(β-
(3-t-butyl-4-hydroxy-5-methylphenyl)propionyloxy)ethyl-2,4,8,10-
Tetraoxaspiro[5,5]undecane; tris-(
3,5-di-monobutyl-4-hydroxybenzyl)-
Examples include isocyanurate and the like.

In addition, as diphenylmonoalkoxyphenol, 2
．． Examples include 6-diphenyl-4-methoxyphenol, and further examples of tetraalkylphenol include tris-
(4-tert-butyl-2,6-di-methyl-3-hydroxybenzyl)-isocyanurate; pentaerythyl-
Examples include tetrakis [3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate].

As for the phenolic antioxidant which is the CD) component, trialkylphenol and tetraalkylphenol are preferred among these. As the trialkylphenol, n-octadecyl-3-(4-hydroxy-3,
5-di-t-butylphenyl)propionate; tetrakis[methylene(3,5-di-t-butyl-4-hydroxyhydrocinnamate)]]methane; 3,9-bis1.1di-methyl-2- (β-(3-t-butyl-4-
Hydroxy-5-methylphenyl)propionyloxy)ethyl-2,4,8,10-tetraoxaspiro[5
, 5] undecane: tris-(3,5-di-t-butyl-4-hydroxybenzyl)-isocyanurate is preferred. Tetraalkylphenols include tris-(4-t-butyl-2,6-di-methyl-3-hydroxybenzyl)-isocyanurate; pentaerythyl-tetrakis(3-(3,5-di-t- -butyl-4
-hydroxyphenyl)propionate] is preferred.

Next, there is no particular restriction on the sulfur-based antioxidant, which is component (E), and general sulfur-based antioxidants can be used, but thioether-based ones are preferable, and specifically, dilauryl-3,3'-thiodipropionate;simiristyl-3,3'-thiodipropionate: distearyl-
3,3'-thiodipropionate;pentaerythritol-tetrakis-(β-lauryl-thiopropionate); bis[2-methyl-4-(3-n-alkylthiopropionyloxy)-5-t-butylphenyl ] Sulfide; 2-mercaptobenzimidazole and the like. Among these, distearyl-3,3'-thiodipropionate; pentaerythritol-tetrakis-(β-lauryl-thiopropionate) is particularly preferably used.

In the present invention, the phenolic antioxidant (D) is added in an amount of 0.05 to 0.4 parts by weight, preferably 0.1 to 0.
．． It is blended in a proportion of 35 parts by weight. If the blending ratio of component (D) is less than 0.05 part by weight, the thermal stability will be poor, so it is not preferable.
If it exceeds 4 parts by weight, it is not preferable because heat resistance decreases.

In addition, (E) the sulfur-based antioxidant is 0.1 to 100 parts by weight per 100 parts by weight of the above-mentioned components (A) and (B).
It is blended in a proportion of 0.6 parts by weight, preferably 0.15 to 0.51 parts by weight. If the blending ratio of component (E) is less than 0.1 part by weight, thermal stability will be poor, which is not preferable.

On the other hand, if the blending ratio of component (E) exceeds 0.6 parts by weight, it is not preferable because heat resistance decreases.

Furthermore, the total amount of the components (D) and (E) is preferably 0.2 to 0.7 parts by weight based on the total IQ+1 parts by weight of the components (A) and (B).

Here, the total amount of component (D) and component (E) is 0.7 ii
If the amount is more than 0.2 parts by weight, heat resistance will deteriorate, while if it is less than 0.2 parts by weight, thermal stability will be poor.

In the present invention, as described above, it is necessary to use (D) a phenolic antioxidant and (E) a sulfur-based antioxidant in combination, but a particularly preferred combination is as follows: (3,5-di-t-butyl-4-hydroxybenzyl)-isocyanurate (trade name MARK AO-20, manufactured by Adeka Argus) and/or ■pentaerythyltetrakis [3-(
3,5-di-t-butyl-4-hydroxyphenyl)propionate] (trade name Irganox 1010, manufactured by Ciba Geigy) and (E) distearyl-3,3-thio as an antioxidant. Dipropionate (trade name Sumilizer TPS, manufactured by Sumitomo Chemical) and/or ■pentaerythritol-tetrakis-(β-lauryl-thiopropionate (trade name Sumilizer TP)
-D, manufactured by Sumitomo Chemical ■) is preferably used in combination.

The polypropylene resin composition of the present invention is prepared by blending the above-mentioned components in predetermined amounts and processing the mixture at 180 to 240°C using a Banbury mixer, 9 screw extruder, twin screw extruder, co-kneader, multi-screw extruder, etc. It is obtained by sufficiently kneading at a temperature of . Further, when manufacturing a molded article from the resin composition of the present invention, it may be carried out by conventional methods such as injection molding and extrusion molding.

Furthermore, in the present invention, an inorganic filler may be added to significantly improve the rigidity of the molded product. Inorganic fillers include talc, calcium carbonate, magnesium carbonate, calcium sulfate, calcium sulfite, magnesium sulfate, and kaolin.

Titanium oxide, zinc oxide, alumina, etc. can be used, and talc and calcium carbonate are particularly preferred. The inorganic filler to be added is preferably fine particles with a particle size of 3 μm or less.

If the particle size is 3 μm or more, the improvement in rigidity is insufficient;
This is not preferred because impact resistance decreases. The appropriate amount of the inorganic filler to be blended is 10 to 100 parts by weight, preferably 15 to 40 parts by weight, based on a total of 100 parts by weight of components (A), (B) and (C). Further, the inorganic filler may be added at the same time as the components (8) to (E), or may be added in a predetermined amount after the components (A) to (E) are kneaded.

[Example] Next, the present invention will be explained with reference to Examples, but the present invention is not limited thereto unless it exceeds the scope of the present invention.

Example 1 Block polypropylene (product name: Idemitsu Polypro J-7
8514. Made by Idemitsu Petrochemical ■, Melt Index (M
I) = 10g/10min) (hereinafter referred to as block PP
It is called. ) 85 parts by weight, impact-resistant polystyrene (product name: Idemitsu Styrene HT51. Made by Idemitsu Petrochemical Cod,
M! = 2 g/lo min) (hereinafter referred to as HIPS) (hereinafter referred to as HIPS) to a total of 100 parts by weight, styrene-butadiene-styrene block copolymer (trade name: Kaliflex T81102゜Shell Chemical ■) as a compatibilizer. (hereinafter referred to as SBS), tris-(3,5-di-t-
0.2 parts by weight of butyl-4-hydroxybenzyl)-isocyanurate (trade name: MARKAn-20, manufactured by Adeka Argus), and distearyl-3,3'-thiodipropionate as a sulfur-based antioxidant. (Product name: Sumilizer TPS, manufactured by Sumitomo Chemical ■) was mixed in 0.331 parts, tri-blended, and then kneaded using a single-shaft kneader at a temperature of 200°C and a rotation speed of 80 rpm to form pellets. Obtained. Thereafter, a test piece was obtained by injection molding, and after being left in an oven at 140°C for a predetermined time, a bench test and a surface impact test at -30°C as shown below were conducted. The results are shown in Table 1.

Samples of 52 Saturn Blue 70mm x 70ffillll x 31111 were placed in an oven at 140°C for 100 hours each, 200
After residence for 300 hours, both ends of the sample were held on a bench and bent 18° to observe the fracture morphology. In the table, ND
indicates non-destruction and D indicates destruction.

Place the samples in the oven at 140℃ for 100 hours each,
After staying for 00 hours and 300 hours, an automatic drop @ impact test was conducted.
In the table 0, conducted under the conditions of 8 kg load and 5 @/sec,
ED indicates stretching fracture, and BD indicates brittle fracture.

Example 2 In Example 1, the blending amount of the antioxidant was 1+1AR, AO-200, 1 part by weight, Sumilizer TPS O,4
The same procedure as in Example 1 was carried out except that the parts by weight were changed. The results are shown in Table 1.

Example 3 The same procedure as in Example 1 was carried out except that 3 parts by weight of Sumilizer TP-DO0 was used instead of Sumilizer TPS as the sulfur-based antioxidant. The results are shown in Table 1.

Example 4 In Example 1, MA was used as a phenolic antioxidant.
Irganox 10100 instead of RK AO-20
．． The same procedure as in Example 1 was carried out except that 2 parts by weight was used. The results are shown in Table 1.

Example 5 Instead of SBS as the compatibilizer in Example 1! A rubber LC made by partially or completely hydrogenating the butadiene portion of a styrene-butadiene block copolymer. Trade name: Kraton G1650, manufactured by Shell Chemical ■ (hereinafter referred to as 5EB
It is called S. ) Example 1 except that 12 parts by weight was used.
I did the same thing. The results are shown in Table 1.

Example 6 In Example 5, the amount of antioxidant added was MARKAO.
-200, 1 part by weight, and Sumilizer TPSO, 15 parts by weight, were carried out in the same manner as in Example 5. The results are shown in Table 1.

Comparative Example 1 In Example 1, MARK AO-
Example 1 except that 0.15 parts by weight of Irganox 10100 was used instead of 20 and Sumilizer TPS.
I did the same thing. The results are shown in Table 1.

Comparative Example 2 The same procedure as Comparative Example 1 was conducted except that the amount of Irganox 1010 was 0.5 parts by weight. The results are shown in Table 1.

Comparative Example 3 In Comparative Example 1, Irganox 1 was used as an antioxidant.
The same procedure as Comparative Example 1 was conducted except that 010 was replaced with 10760.5 parts by weight of Irganox 1076. The results are shown in Table 1.

Comparative Example 4 In Example 1, MARKAO-2 was used as an antioxidant.
The same procedure as in Example 1 was carried out except that only 5 parts by weight of Sumilizer TPSO was used instead of 2 parts by weight of Sumilizer TPSO and 3 parts by weight of Sumilizer TPSO. The results are shown in Table 1.

Example 7 The same procedure as in Example 1 was carried out except that SBS was changed to 20 parts by weight. The results are shown in Table 1.

Example 8 In Example 1, 70 parts by weight of block PP and HIP
The same procedure as in Example 1 was conducted except that S was 30 parts by weight and SBS was 17 parts by weight. The results are shown in Table 1.

[Effects of the Invention] By controlling the particle size of the dispersed phase and the morphology of the compatibilizer, the polypropylene resin composition of the present invention has mechanical properties that can be used as an industrial material, and has excellent solid phase adhesive properties. It has excellent properties and also has good thermal stability under harsh conditions. Therefore, the molded products obtained from the resin composition of the present invention are useful as materials for the automobile field, etc. Patent applicant: Idemitsu Petrochemical Co., Ltd.

Claims (1)

[Claims] (1) For a total of 100 parts by weight of (A) polypropylene and (B) styrene resin, 10 parts of (C) compatibilizer was added.
~30 parts by weight, and the component (A), (B
) In a composition in which the ratio of the total amount of component (B) and component (C) to the total amount of component (C) is 0.2 to 0.6, the component (A) and component (B) are added. total of 10
(D) phenolic antioxidant to 0 parts by weight
．． 05 to 0.4 parts by weight, (E) 0 sulfur-based antioxidant
．． A polypropylene resin composition in which each component is blended in a proportion of 1 to 0.6 parts by weight.