JPH023424B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to highly transparent propylene polymer composition injection molded articles. Isotactic polypropylene is conveniently used in a wide range of fields because of its excellent practical performance, but because it is crystalline, its transparency may be poor and its commercial value may be impaired. In order to improve this drawback, various methods of adding nucleating agents have been tried. Examples of nucleating agents include aluminum salts of aromatic carboxylic acids,
Known examples include aromatic carboxylic acids, aromatic metal phosphates, and condensates of polyhydric alcohols and aldehydes. In particular, 1,3,2,4-dibenzylidene sorbitol is relatively effective, but has not yet reached a level that satisfies recent advanced demands. In addition, di-substituted benzylidene sorbitol is a nucleating agent that has a greater effect on improving transparency than 1,3,2,4-dibenzylidene sorbitol (Japanese Patent Publication No. 55-12460, JP-A No. 56-30449, JP-A No. 56-30449).
30450, Publications Nos. 56-45934), this material is expensive, and if used in large quantities, it may cause bleeding problems, so it is absolutely necessary to establish a technology that improves transparency with the addition of as little amount as possible. This is a challenge. The present invention aims to provide a solution to this problem, and has surprisingly improved transparency by combining a specific di-substituted benzylidene sorbitol and a specific compound with a propylene polymer. This was done after it was discovered that it was possible to obtain injection molded products. That is, the present invention is an injection molded product of a propylene polymer composition, which is characterized by containing the following components (A) to (C). (A) 100 parts by weight of a propylene polymer with a melt flow rate of 0.1 to 100 g/10 minutes (B) 0.01 to 0.5 parts by weight of a compound represented by the following formula (In the formula, R is either alkyl, alkoxy or halogen having 1 to 8 carbon atoms, and may be different in the same compound. m and n are each independently an integer of 0 to 3, and m+n≧1
It is. ) (C) At least one selected from stearyl lactate metal salt and alkyl alcohol having 8 to 30 carbon atoms.
0.01-1% by weight of one compound (In the formula, R ₁ is an alkyl group having 8 to 30 carbon atoms, k
and l are each independently an integer of 0 to 10, and k+l≧1. ) The propylene polymer that 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 effects of the present invention are significantly exhibited in crystalline products. Specifically, for example, in addition to propylene homopolymers,
The majority (preferably 70% by weight or more) of propylene and other α-olefins (e.g. ethylene, butene-1, 4-methylpentene-1, hexene-1
etc.) are suitable. MFRs other than those listed above are undesirable as they result in poor molding. Further, the di-substituted benzylidene sorbitol, which is the component (B) used in the present invention, is a compound represented by the following formula. (In the formula, R is either alkyl, alkoxy or halogen having 1 to 8 carbon atoms, 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, R is alkyl such as methyl, ethyl, n-propyl, i-propyl, t-butyl, alkoxy such as methoxy, ethoxy, n-propoxy, or halogen such as chlorine or bromine. is appropriate. Furthermore, examples of the stearyl lactate metal salt used in the present invention as the component (C) include calcium stearyl lactate and the like. Further, examples of the alkyl alcohol having 8 to 30 carbon atoms include stearyl alcohol and lauryl alcohol. The blending ratio of the above three components is 0.01 to 0.5 parts by weight, preferably 0.05 to 0.3 parts by weight, of di-substituted benzylidene sorbitol as component (B) and 100 parts by weight of propylene polymer as component (A), and (C ) component compound is 0.01 to 1 part by weight, preferably 0.01 to 0.5 part by weight,
Particularly preferably, the amount is 0.01 to 0.3 parts by weight for the stearyl lactate metal salt, and 0.05 to 0.5 part by weight for the alkyl alcohol. Component (B) is expensive, and the greater the amount, the greater the possibility that bleeding will become a problem, so it should be used in a small amount as described above. However, if the amount is less than the above, the effect will be unsatisfactory. Furthermore, if component (C) exceeds the above amount, it will cause coloring or bleeding, and if it is less than the above amount, the effect will be too low. The composition used in the present invention includes, as other ingredients,
The effects of the present invention can be achieved by adding commonly used antioxidants, metal salts other than component (C) above, ultraviolet absorbers, lubricants, antistatic agents, dispersants, pigments, clarifying agents, gelling agents, molecular weight regulators, etc. It can be added within a range that does not cause significant damage. The composition used in the present invention can be manufactured by a conventional kneading method. That is, for example, component (A), propylene polymer powder, is blended with component (B) and component (C), as well as other additives such as antioxidants if necessary, mixed in a mixer, etc., and then processed in an extruder. Melt and knead to make pellets. The pellets are molded into molded articles by injection molding. Of course, the powder mixed in the above-mentioned mixer or the like may be directly subjected to molding. In addition, a method in which component (C) or (B) is attached or added to a composition in which only component (B) or (C) above is blended with component (A) to form a pellet, and then subjected to molding. Also good. Example As shown in Table 1, (B) was added to 100 parts by weight of propylene-ethylene random copolymer (MFR 14 g/10 minutes, ethylene content 2.5% by weight) as component (A).
The components di-substituted benzylidene sorbitol and component (C) were blended together with an antioxidant, mixed in a super mixer, and pelletized in a 30 mm diameter extruder (230°C). The pellets were molded into sheets of 100 x 100 x 1 mm each using an injection molding machine (280°C).
The transparency (haze) of this sheet was evaluated in accordance with JIS-K6714. The results are shown in Table 1. The compounds with names in the table are as follows. Gel All MD: manufactured by Shin Nippon Rika Co., Ltd., 1, 3, 2,
4-di(p-methylbenzylidene) sorbitol. LAA: Calcium stearyl lactate manufactured by Musashino Chemical Research Institute. St-OH: Stearyl alcohol (reagent). 【table】

Claims (1)

[Scope of Claims] 1. An injection molded product of a propylene polymer composition, characterized by blending the following components (A) to (C). (A) 100 parts by weight of a propylene polymer with a melt flow rate of 0.1 to 100 g/10 minutes (B) 0.01 to 0.5 parts by weight of a compound represented by the following formula (In the formula, R is either alkyl, alkoxy or halogen having 1 to 8 carbon atoms, and may be different in the same compound. m and n are each independently an integer of 0 to 3, and m+n≧1
It is. ) (C) At least one selected from stearyl lactate metal salt and alkyl alcohol having 8 to 30 carbon atoms.
0.01-1% by weight of one compound.