JPH02265940A - Polypropylene resin composition - Google Patents

Abstract

PURPOSE:To make it possible to easily increase the degree of crystallinity of the obtained polymer and to obtain a polypropylene resin composition improved in bending modulus, tensile yield strength, etc., by mixing a crystalline polypropylene with a styrene (derivative)/dialkenylbenzene copolymer (nucleus- hydrogenated product). CONSTITUTION:A crystalline polypropylene (A) is mixed with a polymer (B) obtained by copolymerizing a styrene (derivative) with a dialkenylbenzene (e.g. divinylbenzene) and/or a polymer (B) obtained by hydrogenating this polymer to produce a highly crystalline polypropylene resin composition. An example of a process for mixing component B with component A consists of mixing a powder of component A with a powder of component B with e.g. a Henschel mixer and melt-kneading the mixture with an extruder. In order to improve the dispersibility, it is desirable that propylene is polymerized with a transition metal catalyst containing component B, and the obtained polypropylene is mixed with component A.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a crystalline polypropylene resin composition. Specifically, the present invention relates to a crystalline polypropylene resin composition containing a specific polymer.

(Prior art) Polypropylene is a polymer with excellent rigidity, but there is a problem in that the crystallinity of molded products is relatively low and the physical properties of ordinary molded products are inferior to the originally expected physical properties. Usually, a method of adding various nucleating agents is carried out, and a molded product with excellent rigidity or transparency is obtained.

[Problem to be solved by the invention]

The method of adding a nucleating agent is convenient and effective, but it requires the addition of a relatively large amount of nucleating agents, which may cause variations in the physical properties of the molded product due to poor dispersion of the nucleating agent, or bleed of the added nucleating agent. There was a problem. For this purpose, it is known to add a specific polymer compound (Japanese Unexamined Patent Publications No. 60-139731, No. 61-16944), these methods are extremely effective, but effective polymer compounds are not yet available. For this purpose, there was a problem that the synthesis of 'i-mer and the polymerization of monomers were complicated and difficult due to problems such as isomerization. It is known to use a nuclear hydrogenated product (Japanese Unexamined Patent Publication No. 63-120751), but even this was insufficient in terms of effectiveness.

[Means to solve the problem]

The present inventors have diligently searched for a composition that is more effective and easier to manufacture, and have arrived at the present invention.

That is, the present invention is a highly crystalline polypropylene resin composition containing a polymer obtained by copolymerizing a styrene derivative and dialkenylbenzene and/or a polymer obtained by further nuclear hydrogenation. This is a highly crystalline polypropylene resin composition containing polypropylene obtained by polymerization using a solid catalyst containing a polymer obtained by copolymerizing and dialkenylbenzene and/or a polymer obtained by further nuclear hydrogenation.

In the present invention, polypropylene is not only a homopolymer of propylene, but also a random or block combination of propylene and a small amount of other polymers such as ethylene, butene-1, hexene-1, etc., as long as the polymer is crystalline. Also contains copolymers.

Styrene is not only styrene but also nuclear substituted derivatives of styrene, especially y! It also shows the converted derivatives.
Dialkenylbenzene is a compound in which two hydrogen atoms of benzene are substituted with an alkenyl group having 2 to 3 carbon atoms, and specific examples thereof include divinylhensen and shiisorobenylbenzene.

The quantitative ratio of the above two types of monomers is 0.00 to 100 parts of styrene or its derivative, in order to facilitate mixing with propylene. It is about O1-10. Polymerization may be radical polymerization, anionic polymerization, or cationic polymerization, and there is no particular restriction on the copolymerization method for each polymerization method.
00・-200'C, -100 to 2 for anionic polymerization
Cationic polymerization is carried out at a temperature of about -100 to 50'C and a 7-mer concentration of 0.01M to bulk polymerization.

There are no particular restrictions on the method of nuclear hydrogenation of the copolymer, and any known method can be used as desired. Pressurized hydrogen using noble metal catalysts such as palladium, platinum, ruthenium, or those supported on carbon or alumina, etc.
It is possible to use the usual method such as processing. Nuclear hydrogenation is more effective than using it as is without nuclear hydrogenation, but hydrogenation does not have to be complete.
If at least %, more preferably at least 40%, of the benzene rings are nuclear hydrogenated, the same effect as when all the benzene rings are nuclear hydrogenated can be obtained. On the other hand, for polystyrene not copolymerized with dialkenylbenzene, preferably 80%
A sufficient effect of improving physical properties cannot be obtained unless the above benzene ring is nuclear-hydrogenated.

In the present invention, the polypropylene whose physical properties are improved by adding a copolymer of styrene and dialkenylbenzene or its nuclear hydrogenated product is not particularly limited as long as it is crystalline polypropylene, and titanium trichloride or tetrachloride may be used. Known stereoregularity catalysts such as transition metal catalysts obtained by supporting titanium on magnesium halide or those further treated with electron-donating compounds, organometallic compounds such as organoaluminium, and further electron-donating compounds as necessary. Examples include those obtained by random or block copolymerization of propylene alone or with a small amount of olefin such as ethylene, butene-11hexene-1, etc., using a catalyst, and many brands are commercially available.

There are no particular restrictions on the method of mixing polypropylene with a copolymer of styrene and dialkenylbenzene or its nuclear hydrogenated product, and a method such as powder mixing in a normal Henschel mixer and then melt mixing in an extruder is sufficient. It is possible to mix, but in order to achieve better mixing and dispersion, polypropylene obtained by polymerizing propylene with a transition metal catalyst containing a copolymer of styrene and dialkenylbenzene or a nuclear hydrogenated product thereof is changed to polypropylene that does not contain the copolymer. More preferably, they are mixed.

The mixing ratio of a copolymer of styrene and dialkenylbenzene or its nuclear hydrogenated product and polypropylene that does not contain it is 0.05 to 1000 polystyrene units or its hydrogenated units to polypropylene.
It is about 0 pp-, more preferably about 1 to 1000 ρp-. If it is less than that, the effect will not be sufficient, and if it is added more than that, it will not be particularly effective.

It is of course possible to add known additives such as oxidation stabilizers and ultraviolet absorbers or fillers such as talc when producing the composition.

[Example] The present invention will be further explained with reference to Examples below.

Example I M Styrene 50aM in a 500-ml flask under a stream of bare air
(・Luene 50ml and divinylbenzene 0.5
After adding id and mixing, add 0.1g of polyvinyl alcohol.
Add 500ml of water and 1g of potassium persulfate dissolved in 9
The mixture was stirred at 0°C for 20 hours, then filtered and the polymer was thoroughly washed with methanol to obtain 42 g of a copolymer of styrene and divinylbenzene. The ratio of divinylbenzene in the copolymer calculated from the amounts of unreacted styrene and divinylbenzene was Q, 8wtχ. This copolymer was heated in decalin at 170°C using palladium carbon (palladium low L% supported) as a catalyst at a hydrogen partial pressure of 30 kg/
The mixture was treated with C for 20 hours, and then nuclear water was added. “C-NM
The proportion of hydrogenated nuclei determined by R was 97%.

Polypropylene Jll) I-G manufactured by Mitsui Toatsu Chemical Co., Ltd.
The following physical properties were measured for a composition obtained by adding 0.01 part by weight of the above hydrogenated copolymer to 100 parts by weight and granulating it with an extruder.

・Bending elastic modulus: kg/cd ASTM D638
(23°C) Tensile yield strength: kg/cd
ASTM D63B (23℃) In addition, for propylene-ethylene copolymer, ・Izod (・(notched) impact strength: kg-Cm/
cd8ST to [1256-56 (23°C1-1O°
C) was also measured. The results are shown in Table 1.

Comparative Example 1 The same procedure as in Example 1 was carried out without using the hydrogenated copolymer, and the physical properties were measured, and the results shown in Table 4 were obtained.

Comparative Example 2 Polystyrene obtained by polymerizing only styrene without using divinylbenzene was similarly nuclear-hydrogenated to obtain nuclear-hydrogenated polystyrene with a hydrogenated nucleus ratio of 98%. A polypropylene resin composition was obtained in the same manner as in Example 1 except that this polymer was used. The physical properties were similarly measured and the results are shown in Table 1.

Example 2 Polypropylene block copolymer BJIIH-G part manufactured by Mitsui Toatsu Chemical Co., Ltd. was used as crystalline polypropylene,
A polypropylene resin composition was obtained by melt-mixing in the same manner as in Example 1, except that the amount of the hydrogenated copolymer obtained in Example 1 was changed to 0.1 part by weight. When the physical properties of this composition were similarly measured, the results shown in Table 1 were obtained.

Comparative Example 3 In Example 2, the same procedure as in Example 2 was carried out without using the hydrogenated copolymer, and the physical properties were measured, and the results shown in Table 1 were obtained.

Example 3 A graft polymer with a hydrogenated core content of 40% was obtained by shortening the hydrogenation time. This graph] 10g of polymer, 50g of titanium trichloride (TAC-140 manufactured by Toho Titanium Co., Ltd.), 1g of a pulverized product obtained by co-pulverizing nophenyl ether 5d, and n-hebutane using a catalyst consisting of diethylaluminum chloride 5- Polymerize propylene at 70 °C to obtain a graft polymer], η containing 200 ppm is 1.48,
A polypropylene with a content of 97.2% of the residue extracted with boiling 11n-heptane was obtained. The same procedure as in Example 1 was carried out except that 1021 parts of this polymer was used. The results are shown in Table 1.

〔Effect of the invention〕

The composition of the present invention is easy to produce, has excellent physical properties, and is of great industrial value.

Patent applicant Mitsui Toatsu Chemical Co., Ltd.

Claims (1)

[Scope of Claims] 1. A highly crystalline polypropylene resin composition containing a polymer obtained by copolymerizing a styrene derivative and dialkenylbenzene and/or a polymer obtained by further nuclear hydrogenation. 2. Highly crystalline polypropylene resin composition containing polypropylene obtained by polymerization using a solid catalyst containing a polymer obtained by copolymerizing a styrene derivative and dialkenylbenzene and/or a polymer obtained by further nuclear hydrogenation. thing.