JPH06874B2 - Propylene polymer composition injection molded product - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to injection molded articles of propylene polymer compositions having highly improved transparency.

[0002]

2. Description of the Related Art Isotactic polypropylene is easily used in a wide variety of fields due to its excellent practical performance, but its crystallinity may impair its transparency and impair its commercial value. In order to ameliorate this drawback, a method of adding various nucleating agents has been tried so far. Known examples of the nucleating agent include aluminum salts of aromatic carboxylic acids, aromatic carboxylic acids, aromatic phosphoric acid metal salts, and condensation products of polyhydric alcohols and aldehydes.

[0003]

In particular, 1, 3, 2, 4
-Although dibenzylidene sorbitol is relatively effective, it has not yet reached the level that satisfies the recent high demands. In addition, as a nucleating agent having a greater transparency improving effect than 1,3,2,4-dibenzylidene sorbitol, di-
There is a substituted benzylidene sorbitol (Japanese Patent Publication Sho 55-
12460, JP-A-56-30449, JP-A-56-304
No. 50, No. 56-45934), this product is expensive and, if used in large amounts, causes a problem of bleeding. Therefore, it is necessary to establish a technique for improving transparency by adding as little as possible. It is an issue.

[0004]

[Summary of the Invention] The present invention is intended to provide a solution to this problem, in which a specific di-substituted benzylidene sorbitol and a specific compound are added to a propylene polymer. Surprisingly, it was made clear that an injection-molded article with highly improved transparency can be obtained by blending together. That is, the present invention is an injection-molded article of a propylene polymer composition, characterized by comprising the following components (A) to (C). (A) Melt flow rate is 0.1 to 100 g / 10
Minutes propylene polymer 100 parts by weight (B) 0.01 to 0.5 parts by weight of a compound represented by the following formula

[0005]

[Chemical 2] (In the formula, R is any of alkyl having 1 to 8 carbons, same alkoxy or halogen, and may be different in the same compound. M and n are each independently an integer of 0 to 3, and m + n ≧ 1.) (C) Alkyl alcohol having 8 to 30 carbon atoms 0.01
~ 1% by weight

DETAILED DESCRIPTION OF THE INVENTION The propylene polymer, which is the component (A) used in the present invention, has a melt flow rate (MFR) of 0.1 to 100 g.
/ 10 minutes, and the crystalline one exhibits the effect of the present invention remarkably. Specifically, for example, in addition to a propylene homopolymer, a majority (preferably 70)
Random or block copolymers of propylene (by weight or more) with other α-olefins (eg ethylene, butene-1,4-methylpentene-1, hexene-1 etc.) are preferred. If the MFR is other than the above, it is not preferable because of poor molding. Further, the above-mentioned component (B) used in the present invention, di-substituted benzylidene sorbitol, is a compound represented by the following formula.

[0007]

[Chemical 3] (In the formula, R is any of alkyl having 1 to 8 carbons, same alkoxy or halogen, and may be different in the same compound. M and n are each independently an integer of 0 to 3, and m + n ≧ 1) Specifically, as R, alkyl such as methyl, ethyl, n-propyl, i-propyl, t-butyl or alkoxy such as methoxy, ethoxy, n-propoxy or halogen such as chlorine or bromine is used. Appropriate. Further, the alkyl alcohol having 8 to 30 carbon atoms which is the component (C) used in the present invention includes stearyl alcohol and lauryl alcohol.

The mixing ratio of the above three components is 0.01 to 0.5 part by weight, preferably 0 to 0.5 part by weight of the di-substituted benzylidene sorbitol as the component (B), relative to 100 parts by weight of the propylene polymer as the component (A). .05-0.3 parts by weight and (C)
0.01 to 1 part by weight of the component compound, preferably 0.0
1 to 0.5 parts by weight, particularly preferably 0.05 to 0.5 parts by weight. The component (B) is expensive, and the larger the amount, the more likely bleeding becomes a problem. Therefore, the component (B) should be used in a small amount as described above. However, if the amount is less than the above amount, the effect becomes unsatisfactory. Further, when the component (C) exceeds the above amount, it causes coloring and bleeding, and when it is less than the above amount, the effect is too low.

Other components of the composition used in the present invention include antioxidants, clarification aids such as metal salts, ultraviolet absorbers, lubricants, antistatic agents, dispersants, pigments, which are commonly used.
Clarifying agents, gelling agents, molecular weight modifiers and the like can be added within a range that does not significantly impair the effects of the present invention.

The composition used in the present invention can be produced by a conventional kneading method. That is, for example, the propylene polymer powder of the component (A) is blended with the component (B) and the component (C), and if necessary, other additives such as an antioxidant, and after mixing with a mixer or the like, the mixture is mixed with an extruder. Melt and knead into pellets. By injection molding method using this pellet,
Make a molded product of the mold. Of course, the powder material mixed by the above mixer may be directly subjected to molding. Alternatively, a method may be used in which only the component (B) or (C) is blended with the component (A) to form a pellet, and the component (C) or (B) is attached or added to the composition for molding. .

[0011]

Examples Example 1 and Comparative Examples 1 to 5 Table 1 shows 100 parts by weight of a propylene-ethylene random copolymer (MFR 14 g / 10 min, ethylene content 2.5% by weight) as the component (A). As described above, the di-substituted benzylidene sorbitol as the component (B) and the component (C) were mixed with an antioxidant, mixed with a super mixer, and then pelletized with a 30 mm diameter extruder (230 ° C.). These pellets are 100 by injection molding machine (280 ° C).
Molded into a sheet of 100 mm x 100 mm x JIS-K671
According to 4, the transparency (haze) of this sheet was evaluated. The results are shown in Table 1. The compounds with the names in Table 1 are as follows. Gel All MD: 1,3,2,4-made by Shin Nippon Rika Co., Ltd.
Di (p-methylbenzylidene) sorbitol. St-OH: Stearyl alcohol (reagent).

Table 1 _No. (B) component weight part (C) component weight part Haze gel all MD St-OH (%) Comparative Example 1-40 〃 2 0.1 -21 〃 3 0.15 -14 〃 4 0.2-12 〃 5-0.1 41 Example 1 0.1 0.1 13

[0013]

The propylene polymer composition injection-molded article of the present invention obtained by blending a specific di-substituted benzylidene sorbitol and a specific alkyl alcohol in a propylene polymer has the addition of di-substituted benzylidene sorbitol. Since it is possible to improve the transparency to a high degree by reducing the amount to a minimum, it is possible to manufacture an injection-molded article with high transparency at low cost.

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Claims (1)

[Claims] 1. A propylene polymer composition injection-molded article comprising the following components (A) to (C). (A) Melt flow rate is 0.1 to 100 g / 10
100 parts by weight of propylene polymer (B) 0.01 to 0.5 parts by weight of a compound represented by the following formula: (In the formula, R is any of alkyl having 1 to 8 carbons, same alkoxy or halogen, and may be different in the same compound. M and n are each independently an integer of 0 to 3, and m + n ≧ 1.) (C) Alkyl alcohol having 8 to 30 carbon atoms 0.01
~ 1% by weight.