JPH0564172B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to crystalline propylene polymer compositions with significantly improved transparency. Propylene polymer is an excellent crystalline resin with high rigidity and mechanical strength, but due to the large difference in refractive index between crystalline and amorphous parts, its transparency may be poor depending on the field of use. Product value may be lost. For this reason, several attempts to improve transparency have been proposed so far. For example, aluminum or sodium salts of aromatic carboxylic acids (JP-A-58-
80329), aromatic carboxylic acids, aromatic phosphate metal salts, sorbitol derivatives (Japanese Patent Publication No. 12460/1983)
It is known that when spherulites are added, such as those described in Japanese Patent Application Laid-Open No. 129036/1983, they act as a nucleating agent for crystal nuclei, reducing the size of spherulites and improving transparency.
In particular, sorbitol derivatives exhibit excellent transparency effects, but sorbitol derivatives have low compatibility with resins and may cause bleeding problems.
Furthermore, depending on the conditions, it is easy to thermally decompose, and odor may become a problem during or after processing, so it is necessary to improve transparency by adding as little as possible. The present inventors have conducted intensive studies in view of these drawbacks, and have found that transparency can be significantly improved by combining a vinylcycloalkane polymer and a sorbitol derivative with a crystalline propylene polymer. Heading This led to the present invention. That is, the present invention uses 0.01 to 0.5 parts by weight of a compound represented by the following formula to 100 parts by weight of a propylene polymer, and 0.05 wtppm to 0.05 wtppm of a vinylcycloalkane polymer having 6 or more carbon atoms in vinylcycloalkane units.
The present invention relates to a crystalline propylene polymer composition characterized in that it contains 10,000wtppm. (In the formula, R represents an alkyl group or alkoxy group having 1 to 8 carbon atoms, or a halogen atom. R may be different in the same compound. Also, m, n
represents an integer from 0 to 3. The term "crystalline propylene polymer" as used herein means a propylene homopolymer or a random or block copolymer of propylene and another α-olefin having 2 to 18 carbon atoms. Furthermore, the vinylcycloalkane polymer used in the present invention refers to the vinylcycloalkane homopolymer, a random copolymer of the vinylcycloalkane and a small amount of other vinylcycloalkane or α-olefin, or the vinylcycloalkane It means a block copolymer of an alkane and an α-olefin. The vinylcycloalkane block copolymer is, for example, (1)
(2) a copolymer in which the vinylcycloalkane is polymerized in the first step and propylene is homopolymerized in the second step; (2) the vinylcycloalkane is polymerized in the first step and propylene and other A copolymer obtained by random copolymerization with α-olefin, (3) homopolymerization of propylene in the first step, polymerization of the vinylcycloalkane in the second step, and homopolymerization of propylene again in the third step. It is a multi-stage copolymer of two or more stages of the vinylcycloalkane and various α-olefins containing ethylene, such as a copolymer obtained by carrying out the above. Among these vinylcycloalkane polymers, preferred polymers are the block copolymers, and more preferred polymers are block copolymers with propylene as shown in (1) to (3) above. . Vinylcycloalkanes having 6 or more carbon atoms used in the present invention include vinylcyclobutane, vinylcyclopentane, vinyl-3-methylcyclopentane, vinylcyclohexane, vinyl-2-methylcyclohexane, vinyl-3-methylcyclohexane, and vinylnorbornane. etc. The content of the vinylcycloalkane unit in the crystalline propylene polymer composition of the present invention should be 0.05wtppm to 0.05wtppm in order to exhibit the improvement effect without changing the original physical properties of the crystalline propylene polymer.
10000wtppm is required, preferably
0.5wtppm~5000wtppm, more preferably
It is 0.5wtppm to 1000wtppm. The sorbitol derivative used in the present invention is a compound represented by the following formula. (In the formula, R represents an alkyl group or alkoxy group having 1 to 8 carbon atoms, or a halogen atom. R may be different in the same compound. Also, m and n are 0
Represents an integer from ~3. ) Specifically, R is alkyl such as methyl, ethyl, n-propyl, t-butyl, or methoxy;
Alkoxy such as ethoxy and n-proboxy, or halogen such as chlorine and bromine are suitable. The crystalline propylene polymer and the vinylcycloalkane polymer used in the present invention are suitably produced using a catalyst system consisting of a titanium compound and an organoaluminum compound. That is, propylene or the vinyl cycloalkane can be prepared using conventional known polymerization methods for polyolefins, such as slurry polymerization in a hydrocarbon solvent such as hexane, heptane, or benzene, or bulk polymerization in liquefied propylene or the vinyl cycloalkane. It is suitably polymerized by. The polymerization is carried out under conditions of temperature: 20 to 100°C, pressure: atmospheric pressure to 60 kg/cm ² G, and time: several minutes to several tens of hours. Specific examples of the titanium compound used include titanium trichloride catalysts commercially available from Toyo Stoffer Co., Ltd., Toho Titanium Co., Ltd., Marubeni Solvay Co., Ltd., and the like. Also, JP-A-57-
Magnesium-containing titanium compound catalysts described in JP-A No. 59916 and JP-A No. 55-133408 are also preferably used. As organoaluminum compounds,
AlXaL _3-a (X: halogen atom, alkoxy group having 1 to 18 carbon atoms, or hydrogen atom, L: alkyl group having 1 to 18 carbon atoms, a: number satisfying 0≦a<3) Preferably, specific examples of compounds include Al(CH ₃ ) ₃ , Al(C ₂ H ₅ ) ₃ , Al(C ₂ H ₅ )
₂ Cl, Al (C ₂ H ₅ ) ₂ Br, Al (C ₂ H ₅ ) ₂ (OC ₂ H ₅ ), Al
(C ₂ H ₅ ) (OC ₂ H ₅ ) ₂ , Al(C ₂ H ₅ ) ₂ Cl, Al(C ₄ H ₉ ) ₃ ,
Examples include Al(C ₄ H ₉ ) ₂ Cl, Al(C ₆ H ₁₉ ) ₃ , Al(C ₆ H ₁₃ ) ₂ Cl, and mixtures thereof. Furthermore, in order to improve the stereoregularity of the polymer during polymerization, an electron donor such as a carboxylic acid ester, a phosphoric acid ester, or a silicate ester is added to produce a crystalline propylene polymer and the vinylcycloalkane polymer. It is also possible. For blending the crystalline propylene polymer, the vinylcycloalkane polymer, and the sorbitol derivative, a conventional method of blending α-olefin polymers and various additives is suitably used. That is, the crystalline propylene polymer composition of the present invention is prepared by mixing a polymer powder and the sorbitol derivative using a Henschel mixer or the like, and melt-kneading the mixture using a Brabender, roll, Banbury mixer, granulator, or the like. can get. The crystalline propylene polymer composition of the present invention includes:
All types of additives normally incorporated into propylene polymers, such as heat and light stabilizers, antistatic agents, antioxidants, carbon black, pigments, flame retardants, etc., may be incorporated as required. Furthermore, other polymers such as low-density polyethylene, high-density polyethylene, polybutene, and EP rubber, or fillers such as mica and talc can be blended and used. The crystalline propylene polymer composition of the present invention can be made into a wide variety of products such as sheets, films, containers, fibers, etc. by well-known techniques such as injection molding, pressure forming, vacuum forming, extrusion molding, blow molding, and stretching. I can do it. The present invention will be specifically explained below with reference to Examples, but the present invention is not limited thereto. Note that the melt index (M1), [η], internal haze, etc. shown in the examples were measured according to the following methods. (1) Melt index (M1) Measured according to JIS K 6758. (2) [η] Measurement was performed in tetralin at 135°C using an Ubbelohde viscometer. (3) Internal Haze A sample sheet was immersed in a dimethyl phthalate solution and measured in accordance with ASTM D 1746-627.
A sample sheet was produced using the press plate shown in FIG. 1 under the temperature, pressure, and time conditions described in JIS K 6758. Example Propylene homopolymer (M11.0g/10min) 100
Based on parts by weight, 2,6-di-t-butyl-p-
0.2 parts by weight of cresol, tetrakis [methylene-
3(3',5'-di-t-butyl-4-hydroxyphenyl)propionate] 0.05 parts by weight of titanium and 0.05 parts by weight of calcium stearate were added, and further sorbitol derivatives shown in Table 1 and vinyl synthesized by the following method were added. Contains cyclohexane polymer,
After thorough mixing, melt kneading was performed at 230° C. for 5 minutes using Brabender Plastography.
The transparency (internal haze) of these crystalline propylene polymer compositions was evaluated. The results are shown in Table 1. (Synthesis of vinylcyclohexane polymer) Add Al (C ₂ H ₅ ) to 100 ml of dehydrated and purified n-heptane.
₂ Cl0.9g, titanium trichloride catalyst manufactured by Marubeni Solvay
Added 1.07g. After raising the temperature to 60°C, 20 ml of vinylcyclohexane was added and polymerization was carried out for 1.5 hours. After the polymerization is completed, the polymerization slurry is n-C ₇
Unreacted vinylcyclohexane and AR(C ₂ H ₅ ) ₂ Cl were removed by washing twice with 100 ml. The vinylcyclohexane polymer powder containing the activated titanium trichloride catalyst was then dried under reduced pressure.
14.9g was obtained. 13.3g of this polymerized powder, Al( _C2
Hydrogen partial pressure is 0.1 in a stainless steel autoclave using 3.0 g of H ₅ ) ₂ Cl and 2000 ml of n-heptane.
Polymerization of propylene was carried out ^{for 75 minutes at a temperature of 65° C. and a total pressure of 6 kg/cm 2 G.} After the polymerization was completed, 50 ml of n-butanol was added to stop the polymerization, the polymerization slurry was taken out, and the polymer powder and the solvent were separated. The obtained polymer powder was dissolved in 1N hydrochloric acid 500
After washing with methanol, the solution was washed with methanol until the washing solution became neutral. The polymer powder was then dried and weighed to be 470 g. The vinylcyclohexane unit content in this block copolymer of vinylcyclohexane and propylene was determined from the polymerization amount to be 2.6% by weight. Moreover, [η] of this copolymer was 2.7 dl/g.

[Table] From the examples shown in Table 1 above, it can be seen that transparency is significantly improved by incorporating a small amount of vinylcyclohexane polymer and sorbitol derivative into the propylene polymer.

[Brief explanation of the drawing]

FIG. 1 shows an outline of a press plate for measuring samples of optical properties. shows a 1mm SUS plate and shows a 1mm aluminum plate, respectively.

Claims (1)

[Claims] 1. 0.01 to 0.5 parts by weight of a compound represented by the following formula and 0.05 wtppm to 10000 wtppm of a vinylcycloalkane polymer having 6 or more carbon atoms in units of vinylcycloalkane based on 100 parts by weight of a propylene polymer.
A crystalline propylene polymer composition comprising: (In the formula, R represents an alkyl group or alkoxy group having 1 to 8 carbon atoms, or a halogen atom. R may be different in the same compound. Also, m, n
represents an integer from 0 to 3. )