JPH05186646A - Polypropylene-based resin composition - Google Patents

Abstract

PURPOSE:To obtain the subject composition, containing a prescribed amount of a specific benzoic acid-based compound, etc., in a PP-based resin, excellent in rigidity and transparency and useful for injection moldings such as caps, sheet moldings such as binders, packaging films, etc. CONSTITUTION:The objective composition contains (A) 100 pts.wt. PP-based resin and (B) 0.001-10.0 pts.wt. one or more compounds selected from the group consisting of benzoic acid-based compounds such as 2-methyl-3-ethylbenzoic acid expressed by formula I (two or more of R1 to R5 are 1-8C alkyl, 1-8C alkoxyl, halogen, etc.; the rest are H) and acid anhydrides of the benzoic acid- based compounds such as 2-methyl-3-ethylbenzoic anhydride expressed by formula II (three or more of R6 to R15 are 1-8C alkyl, 1-8C alkoxyl, halogen, OH, amino, etc.; the rest are H).

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a polypropylene resin composition. More specifically, it relates to a polypropylene resin composition capable of obtaining a molded product having significantly improved rigidity or transparency.

[0002]

2. Description of the Related Art Polypropylene is used in various fields by taking advantage of its excellent moldability, mechanical properties, electrical properties and solvent resistance. However, as the field of use of polypropylene expands, the performance demanded by the market is high, and therefore improvements have been made from various viewpoints.
In particular, in recent years, the performance of polypropylene has been improved, and improvements in rigidity and transparency, which is originally inferior, have been actively made. As one of the methods for improving such physical properties, there is a method of adding a nucleating agent to polypropylene, and this method has been widely used conventionally. However, even in the present circumstances, a molded product excellent in rigidity or transparency has not been obtained yet.

[0003]

The object of the present invention is to provide a polypropylene resin composition having excellent rigidity or transparency.

[0004]

[Means for Solving the Problems] In view of the current situation as described above,
As a result of intensive studies by the present inventors, it is possible to significantly improve the rigidity or transparency of the polypropylene resin by adding a benzoic acid compound or an acid anhydride of the benzoic acid compound to the polypropylene resin. Thus, the present invention has been completed.

That is, the present invention relates to 100 parts by weight of polypropylene resin, the following general formula:

[0006]

[Chemical 3] A benzoic acid compound represented by (provided that the substituents R _{1 to} R _{5 are}
Among them, at least two or more are the same or different groups selected from an alkyl group having 1 to 8 carbon atoms, an alkoxyl group having 1 to 8 carbon atoms, a halogen group, a hydroxyl group, an amino group, a nitro group and a phenyl group. And the rest are hydrogen atoms. ) And the following general formula,

[0007]

[Chemical 4] An acid anhydride of a benzoic acid compound represented by (wherein at least three or more of the substituents R _{6 to} R ₁₅ have 1 to 1 carbon atoms).
The same or different groups selected from an alkyl group having 8 carbon atoms, an alkoxyl group having 1 to 8 carbon atoms, a halogen group, a hydroxyl group, an amino group, a nitro group, and a phenyl group, and the rest are hydrogen atoms. The present invention relates to a polypropylene resin composition containing 0.001 to 10.0 parts by weight of at least one compound selected from the group consisting of The present invention will be described in detail below.

The polypropylene resin used in the present invention is not particularly limited, but the melt flow rate (MFR) measured at 230 ° C. under a load of 2.16 kg is 0.1.
A crystalline substance is preferable at about 100 g / 10 min, and the effect of the present invention is remarkably exhibited in such a polymer. The polypropylene resin is not only a homopolymer of propylene but also a random copolymer of propylene and one or more other olefins, a block copolymer of propylene and one or more other olefins, and the like. There is no problem even if a copolymer of the above is used.
Other olefins copolymerized with propylene include ethylene, 1-butene, 1-pentene, and 3-methyl-1-.
Butene, 1-hexene, 4-methyl-1-pentene, 1
Examples include 1-olefins having 10 or less carbon atoms such as octene and 1-decene. Such a component to be copolymerized with propylene is usually 30 mol% or less, preferably 15 mol% or less in a random copolymer, and usually 50 mol% or less in a block copolymer, preferably 3 mol% or less.
It is used in an amount of 0 mol% or less.

The production of these polymers is not limited to the case where only one polymerization vessel is used, but the production conditions such as MFR and the copolymerization ratio of the components to be copolymerized with propylene are changed. It may be polymerized continuously.

Examples of the method for polymerizing the polypropylene resin include slurry polymerization, bulk polymerization, gas phase polymerization and the like, and the effect of the present invention is sufficiently exhibited even if the resin is polymerized by any of these methods. It Further, generally, a Ziegler-based catalyst such as a titanium trichloride reduction type catalyst or a magnesium-supported type catalyst is used for the polymerization, but the effect of the present invention is obtained even if the polymer is polymerized by any of these catalyst systems. To be demonstrated. After polymerizing the resin, there is also a process having a deashing step of metal components such as titanium and aluminum mainly derived from the catalyst, an extraction step of low stereoregular components and low molecular weight polymers, and the like. The effect of the present invention is exhibited regardless of the presence or absence of the post-treatment process.

The polypropylene resin composition of the present invention is obtained by adding the following general formula to the above polypropylene resin,

[0012]

[Chemical 5] A benzoic acid compound represented by (provided that the substituents R _{1 to} R _{5 are}
Among them, at least two or more are the same or different groups selected from an alkyl group having 1 to 8 carbon atoms, an alkoxyl group having 1 to 8 carbon atoms, a halogen group, a hydroxyl group, an amino group, a nitro group and a phenyl group. And the rest are hydrogen atoms. ) And the following general formula,

[0013]

[Chemical 6] An acid anhydride of a benzoic acid compound represented by (wherein at least three or more of the substituents R _{6 to} R ₁₅ have 1 to 1 carbon atoms).
The same or different groups selected from an alkyl group having 8 carbon atoms, an alkoxyl group having 1 to 8 carbon atoms, a halogen group, a hydroxyl group, an amino group, a nitro group, and a phenyl group, and the rest are hydrogen atoms. And at least one compound selected from the group consisting of

Here, the alkyl group having 1 to 8 carbon atoms in the above general formula is a linear alkyl group such as methyl group, ethyl group, propyl group, butyl group, amyl group, hexyl group, heptyl group, octyl group and the like. Also included are branched alkyl groups such as i-propyl group, 1-methylpropyl group, t-butyl group, 3-methylamyl group, 2-ethylhexyl group, and 2,4-dimethylhexyl group. As the alkoxyl group having 1 to 8 carbon atoms, a linear alkoxyl group such as methoxy group, ethoxy group, propyloxy group, butoxy group, pentyloxy group, hexyloxy group, heptyloxy group, octyloxy group, and i- Propyloxy group, t-butoxy group, 3-ethylbutoxy group,
An alkoxyl group having a branch such as a 4-ethylhexyloxy group is also included. Further, examples of the halogen group include a fluoro group, a chloro group, a bromo group and an iodo group.

Specific examples of the benzoic acid compound include 2-
Methyl-3-ethylbenzoic acid, 2,4-di-t-butylbenzoic acid, 2,6-dimethylbenzoic acid, 2-propyl-
6-amylbenzoic acid, 2,6-di-i-propylbenzoic acid, 3,4-diethylbenzoic acid, 3,5-dimethylbenzoic acid, 3,5-dibutylbenzoic acid, 2,4,6-trimethylbenzoic acid Acid, 4-t-butyl-2,6-dimethylbenzoic acid, 2,4,5,6-tetraethylbenzoic acid, pentapropylbenzoic acid, 2,3-dipropyloxybenzoic acid, 2,6-dimethoxybenzoic acid 2,4,6-trimethoxybenzoic acid, 2,4,5,6-tetrabutoxybenzoic acid, 2,3-difluorobenzoic acid, 2,6-difluorobenzoic acid, 2,6-dichlorobenzoic acid, 2- Fluoro-3-bromo-6-chlorobenzoic acid, 2,4,6-trifluorobenzoic acid, 4-chloro-2,6-difluorobenzoic acid, pentafluorobenzoic acid, 2,4-diaminobenzoic acid, 2, 5-di Eniru benzoic acid, 2,6-dihydroxybenzoic acid, 3,5-dinitro-benzoic acid, 2,3,
4-trihydroxybenzoic acid, 2,4,5-triaminobenzoic acid, 2,4,5,6-tetrahydroxybenzoic acid, 2-methyl-3-ethoxybenzoic acid, 2-methyl-
6-Fluorobenzoic acid, 2-propyl-3-chloro-5
-Hydroxybenzoic acid, 4-phenyl-2,5-di-t
-Butylbenzoic acid, 2,4-dibutoxy-6-aminobenzoic acid, 2,5-diethyl-4-nitro-6-methoxybenzoic acid and the like can be mentioned.

Specific examples of acid anhydrides of benzoic acid compounds include 2-methyl-3-ethylbenzoic anhydride, 2,4-di-t-butylbenzoic anhydride, 2,6-dimethylbenzoic anhydride. 2,4,6-Trimethylbenzoic anhydride, 2-Methyl-4,6-diethylbenzoic anhydride, 2,4 anhydride
-Di-t-butyl-5-methyl-6-i-propylbenzoic acid, 2-methyl-4-propyl-3,5,6-tributylbenzoic anhydride, 2,4-diethoxybenzoic anhydride,
Anhydrous 2,4,6-trimethoxybenzoic acid, anhydrous 2,6-
Difluorobenzoic acid, 2,4,5,6-tetrayoanhydride
Debenzoic acid, 2,5-diphenylbenzoic anhydride, 2,3,4-trihydroxybenzoic anhydride, 2-methyl-6-fluorobenzoic anhydride, 2,4-dibutoxy-6 anhydride
-In addition to aminobenzoic acid and the like, a condensate of 2,3-dimethylbenzoic acid and 2-methoxy-4-propyloxy-5-ethoxybenzoic acid, 2,3,4-trifluorobenzoic acid and 2-amino- Also included are condensates of benzoic acid compounds having different substituents such as condensates of 4,6-dihydroxybenzoic acid.

Among these benzoic acid compounds or acid anhydrides of benzoic acid compounds, 2,6-dimethylbenzoic acid is particularly preferable from the viewpoint of the effect of improving rigidity or transparency.

The amount of the benzoic acid compound or the acid anhydride of the benzoic acid compound added to the polypropylene resin is 0.001 to 10.0 parts by weight, preferably 0.05 to 10.
It is 1.0 part by weight. If the added amount is less than 0.001 parts by weight, the effect of improving rigidity or transparency is poor, and if the added amount exceeds 10.0 parts by weight, problems such as stickiness may occur and cause a decrease in commercial value. Becomes

Further, the composition of the present invention further comprises various additives for polyolefins generally used, such as phenol-based, phosphite-based and thioether-based antioxidants and fatty acid metals. Salt, metal salt of hydroxy fatty acid, metal salt of alkyl lactic acid, neutralizing agent such as hydrotalcite, benzophenone-based, benzotriazole-based, salicylate-based UV absorber, hindered amine-based light stabilizer, lubricant An antiblocking agent, an antistatic agent, a metal salt of an organic acid, a nucleating agent such as a sorbitol-based agent, a dispersant, a peroxide, a pigment and the like can be added. Further, for the purpose of improving the physical properties of the molded product, it is possible to blend a resin such as polyolefin, polyamide or polyester in addition to the composition of the present invention.

To prepare the composition of the present invention, 0.001 to 1 part of a benzoic acid compound or an acid anhydride of a benzoic acid compound is added to 100 parts by weight of a polypropylene resin.
0.0 parts by weight, preferably 0.05 to 1.0 parts by weight, is added and a stabilizer usually used, for example, pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-) is used.
Hydroxyphenyl) propionate], Tris (2,
4-di-t-butylphenyl) phosphite and calcium stearate are not particularly limited, but are 0.00
Add about 1 to 1.0 parts by weight and roll these compositions.
A suitable kneader such as a plastomill or an extruder may be used to heat and knead at a temperature not lower than the melting point of the polypropylene resin. The resin composition thus obtained is used as a polymer molding material that is applied to ordinary molding methods such as injection molding, extrusion molding and compression molding. It is also possible to obtain a desired molded product by a method of preparing a highly filled resin of the composition used in the present invention in advance and adding these at the time of molding or re-granulation, that is, by adding in a master-batch. Is.

[0021]

The present invention will now be described with reference to the following examples, but these examples do not limit the present invention.

Examples 1 to 3 An ethylene-propylene random copolymer (containing ethylene) was prepared by a gas phase method using a magnesium-supported catalyst prepared by the method described in Example 1 of JP-A-64-105. Amount 6.7 mol%, MFR 5.3g / 10mi
n) was obtained. Irganox 1010: Ciba-Geigi Co., pentaerythrityl-tetrakis [3
-(3,5-di-t-butyl-4-hydroxyphenyl) propionate], 0.05 parts by weight, Irgafos 168: Ciba-Geigy, Tris (2,4-di-t).
-Butylphenyl) phosphite 0.1 part by weight, calcium stearate S: manufactured by NOF CORPORATION, 0.1 part by weight of calcium stearate, and the following commercially available benzoic acid-based compounds in the parts by weight shown in Table 1. , 2,6-CH ₃ : 2,6-dimethylbenzoic acid (A
ldrichChem. Company Ltd.) _2,4,6-CH 3: 2,4,6- trimethyl benzoic acid (AldrichChem companies manufactured) 2,6-F:. 2,6- difluorobenzoic acid (manufactured by Tokyo Kasei Kogyo Co., Ltd.) was added Granulation was performed at 240 ° C. using a 25 mmφ single screw extruder. The granulated resin was molded into a sheet having a thickness of 1 mm by a press molding machine heated to 230 ° C. and used for evaluation of physical properties. The physical property evaluation items and evaluation methods are as follows. Haze: JIS K-7105 Olsen bending rigidity: JIS K-7106 Table 1 shows the evaluation results.

Examples 4-5 Journal of American Chemi
cal Society, 74 , 4110, (195
According to the method described in 2), the following acid anhydrides of benzoic acid compounds were prepared using commercially available benzoic acid compounds. _2,6-CH 3 ah: anhydrous 2,6-dimethyl-benzoic acid _2,4,6-CH 3 ah: prepared anhydrous 2,4,6-trimethyl benzoic acid The compound was prepared in a similar manner as in Example 1 Ethylene-propylene random copolymer (ethylene content of 5.3
Mol%, MFR 9.2 g / 10 min), except that 2,6-dimethylbenzoic acid of Example 1 was replaced by the weight parts shown in Table 2, evaluation was carried out in the same manner as in Example 1. The results are shown in Table 2.

Comparative Example 1 The same resin as in Example 1 was used, except that 2,6-dimethylbenzoic acid was not added, and the same method was used for evaluation. The results are shown in Table 1.

Comparative Example 2 The same resin as in Example 4 was used except that 2,6-dimethylbenzoic anhydride was not added, and the same method was used for evaluation.
The results are shown in Table 2.

[0026]

[Table 1]

[0027]

[Table 2] When various benzoic acid compounds or acid anhydrides of benzoic acid compounds are added to the polypropylene resin from the examples of Tables 1 and 2, the rigidity or transparency of the molded product or both of them are remarkably improved. I understand.

[0028]

The polypropylene resin composition of the present invention can remarkably improve the rigidity or transparency of a molded article. Therefore, products requiring rigidity or transparency, for example, injection molded products such as caps and costume cases, blow products represented by bottles, and sheets such as binders and video cassette cases. It is suitable for producing a molded product, a stretched or non-stretched film molded product represented by a packaging film, and the like.

Claims (1)

[Claims] 1. The following general formula: ## STR1 ## with respect to 100 parts by weight of a polypropylene resin. A benzoic acid compound represented by (provided that the substituents R _{1 to} R _{5 are}
Among them, at least two or more are the same or different groups selected from an alkyl group having 1 to 8 carbon atoms, an alkoxyl group having 1 to 8 carbon atoms, a halogen group, a hydroxyl group, an amino group, a nitro group and a phenyl group. And the rest are hydrogen atoms. ) And the following general formula: An acid anhydride of a benzoic acid compound represented by (wherein at least three or more of the substituents R _{6 to} R ₁₅ have 1 to 1 carbon atoms).
The same or different groups selected from an alkyl group having 8 carbon atoms, an alkoxyl group having 1 to 8 carbon atoms, a halogen group, a hydroxyl group, an amino group, a nitro group, and a phenyl group, and the rest are hydrogen atoms. A polypropylene-based resin composition comprising 0.001 to 10.0 parts by weight of at least one compound selected from the group consisting of