JP2713577B2 - Polypropylene resin composition - Google Patents

Description

The present invention relates to a crystalline polypropylene resin composition containing a specific compound.

[Conventional technology]

Polypropylene is a polymer having excellent rigidity, but has a problem that the crystallinity of the molded product is relatively low and the physical properties of ordinary molded products are inferior to those originally expected. For this, a method of adding various nucleating agents is usually performed,
A molded article excellent in rigidity or excellent in transparency has been obtained.

[Problems to be solved by the invention]

The method of adding a nucleating agent is simple and effective, but
It is necessary to add a relatively large amount of nucleus, and therefore, there is a problem that the physical properties of the molded article are varied due to poor dispersion of the nucleating agent, and that the added nucleating agent bleeds. For this, it is known to add a specific polymer compound, but a more effective compound is desired.

[Means for solving the problem]

The present inventors have diligently searched for a more effective compound and arrived at the present invention.

That is, the present invention is a crystalline polypropylene resin composition comprising a polymer obtained by anionic polymerization of cyclohexyl methacrylate and containing from 0.01 wtppm to 1000 wtppm of the polymer.

The polymer of cyclohexyl methacrylate used in the present invention can be produced by various anionic polymerization catalysts.However, a polymer obtained by polymerization at a relatively low temperature with a Grignard reagent can be preferably used, and as the polymerization method, A known method for producing an isotactic polymer of methyl methacrylate is preferably employed (for example,
Polmer Journal, Vol.17 977-980 (1985), Polymer Let
ters Vol, 9 129-131 (1971)). Although the molecular weight of the polymer of cyclohexyl methacrylate is not particularly limited, it is general to use one having a number average molecular weight of 1,000 to 10,000,000.

In the present invention, the crystalline polypropylene used includes not only a homopolymer of propylene, but also a random or block copolymer with another olefin such as ethylene, and the content of the other olefin is usually 50% by weight. % Or less. The method for producing these propylene polymers is not particularly limited, and usually a catalyst comprising a transition metal catalyst and an organoaluminum compound can be used.

Examples of the catalyst composed of a transition metal catalyst and an organoaluminum compound include various known catalyst systems that provide polypropylene having a high stereoregularity. As the transition metal catalyst, titanium halide is preferably used. A catalyst system comprising a stereoregularity improver such as titanium trichloride obtained by reduction with hydrogen or organoaluminum or those obtained by modifying them with an electron donating compound, and an organoaluminum compound and, if necessary, an oxygen-containing organic compound; Alternatively, a transition metal catalyst obtained by supporting a titanium halide on a carrier such as a magnesium halide or those obtained by treating them with an electron donating compound and an organoaluminum compound, and, if necessary, a stereoregularity improver such as an oxygen-containing organic compound. Are exemplified. (For example, various examples are described in the following literature: Zieglegr-Natta
Catalysts and Polymerization by John Boor Jr (Acad
emic Press), Journal of Macromorecular Sience-Rev
iews in Macromolecular Chemistry and Physics C24.
(3) 355-385 (1984), C25 (1) 578-97 (198)
5)) Here, as the stereoregularity improver or the electron donating compound, oxygen-containing compounds such as ethers, esters, orthoesters, and alkoxysilicon compounds can be preferably exemplified. The electron donating compounds further include alcohols, aldehydes, and the like. Water can also be used.

Examples of the organoaluminum compound include trialkylaluminum, dialkylaluminum halide, alkylaluminum sesquihalide, and alkylaluminum dihalide.Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, and a hexyl group. Examples of the halide include chlorine, bromine and iodine.

Preferred titanium halides are aluminum,
Alternatively, a product obtained by modifying titanium tetrachloride with ether or ester with organoaluminum, or a product obtained by co-milling magnesium chloride and an organic compound with titanium tetrachloride, or a reaction product of magnesium chloride and alcohol Dissolve in the hydrocarbon solvent, then treat with a precipitant such as titanium tetrachloride to make it insoluble in the hydrocarbon solvent, treat with an electron-donating compound such as an ester or ether if necessary, and then treat with titanium tetrachloride. It is a supported titanium halide obtained by a treatment method or the like.

In the present invention, the polymerization of propylene can be performed in an inert medium such as pentane, hexane, heptane, octane, benzene, and toluene, or a bulk polymerization method using propylene itself as a liquid medium, or substantially no liquid medium is present. It can also be carried out by a gas phase polymerization method, and the method is not particularly limited, and various known methods and conditions are adopted.
For example, it is general that the polymerization temperature is from room temperature to 100 ° C., and the polymerization pressure is from normal pressure to 50 kg / cm ² gauge.

In the present invention, the polymer obtained by polymerizing cyclohexyl methacrylate by anionic polymerization and the amount ratio of polypropylene, cyclohexyl methacrylate polymer is 0.01 wtppm or more, preferably 0.1 wtppm ~ 100
It is about 0 wtppm. At 0.01 wtppm or less, there is no effect of improving physical properties, and at 1000 wtppm or more, it is not particularly effective.

〔Example〕

 Hereinafter, the present invention will be further described with reference to examples.

Example 1 A vibrating mill equipped with four crushing pots having a capacity of 4 l and containing 9 kg of steel balls having a diameter of 12 mm was prepared. 300 g of magnesium chloride and tetraethoxysilane in each pot under nitrogen atmosphere
60 ml and α, α, α-trichlorotoluene (45 ml) were added and pulverized for 40 hours. 300 g of the co-ground product thus obtained was placed in a 5 L flask, and 1.5 L of titanium tetrachloride and 1.5 L of toluene were added.
Stir for 0 min, remove the supernatant, add 1.5 L of titanium tetrachloride and 1.5 L of toluene in the same manner, stir at 100 ° C for 30 minutes, remove the supernatant, and wash the solid content repeatedly with n-hexane. A transition metal catalyst slurry was obtained. When a part was sampled and the titanium content was analyzed, it was 1.9 wt%.

40 ml of toluene under a nitrogen atmosphere in a 200 ml internal volume flask,
20 mg of the above transition metal catalyst, 0.128 ml of diethylaluminum chloride, 0.06 ml of methyl p-toluate, and 0.12 ml of triethylaluminum were added to prepare a catalyst slurry. The catalyst slurry was placed in an autoclave having an inner volume of 5 l, and 1.8 kg of propylene and 3.3 Nl of hydrogen were added thereto to carry out a polymerization reaction at 75 ° C. for 2 hours. After the polymerization reaction, unreacted propylene was purged and the polymer was dried at 80 ° C. and 60 mmHg for 12 hours. 380 g of powder was obtained, and the intrinsic viscosity (hereinafter abbreviated as η) measured with a tetralin solution at 135 ° C. and the extraction residual ratio when extracted with boiling n-heptane for 6 hours using a Soxhlet extractor (hereinafter abbreviated as II) (Weight of powder after extraction / weight of powder before extraction is expressed as a percentage).

Using ethylmagnesium chloride as a catalyst, polymerization was performed at −78 ° C. for 12 hours at a catalyst concentration of 0.1 mol / l and a monomer concentration of 2 mol / l in a toluene solvent to obtain polycyclohexyl methacrylate (change rate 92%, in toluene solvent, The intrinsic viscosity at 30 ° C. was 0.18.) Polycyclohexyl methacrylate obtained by the above reaction was added to polypropylene powder.
0, a phenol-based stabilizer 10/10000 weight ratio and calcium stearate were added at 15/10000 weight ratio, the melt flow index was measured, an injection sheet having a thickness of 1 mm was made, and the bending rigidity was measured.

Melt flow index (MI) ASTM D1238 (230 ° C) Flexural rigidity ASTM D747-63 (20 ° C) Also, use a differential thermal analyzer to raise or lower the temperature at 10 ° C / min. The results measured as temperature are shown in the table.

Comparative Example 1 The results obtained in the same manner as in Example 1 except that syndioctatic polycyclohexyl methacrylate was not used are shown in the table.

Example 2 Commercially available highly active titanium trichloride (TAC S manufactured by Toho Titanium)
-21) was used as the transition metal catalyst. Titanium trichloride catalyst
100 mg and 1.0 ml of diethylaluminum chloride were mixed in toluene, then the slurry was placed in a 5-liter autoclave, and 1.8 kg of propylene and 4.4 Nl of hydrogen were added thereto.
Polymerization was performed at 4 ° C. for 4 hours to obtain 920 g of polypropylene. 100 parts of this polypropylene in the presence of 10 ml of propylene oxide.
After treatment at 1 ° C. for 1 hour, the polypropylene powder was taken out. Evaluation was made in the same manner as in Example 1 except that 30 wtppm of the polycyclohexyl methacrylate obtained in Example 1 was used using this polypropylene.

Comparative Example 2 The results obtained in the same manner as in Example 2 except that polycyclohexyl methacrylate was not used are shown in the table.

〔effect〕

The composition of the present invention has extremely excellent physical properties and is industrially valuable.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location C08L 33:10)

Claims (1)

(57) [Claims] 1. A crystalline polypropylene resin composition comprising a polymer obtained by anionic polymerization of cyclohexyl methacrylate in an amount of 0.01 to 1000 ppm by weight.