JPS60139710A - Production of propylene copolymer - Google Patents

Abstract

PURPOSE:To produce a propylene copolymer of excellent crystallizability, by using a Ziegler catalyst, polymerizing a predetermined amount of a vinylcycloalkane in the first stage and then polymerizing propylene in the same reaction system. CONSTITUTION:Propylene (optionally, together with ethylene) is polymerized by using a catalyst system comprising a titanium compound and an organoaluminum compound. In carrying out the above process, a vinylcycloalkane (preferably, 8C or higher one) in an amount of about 0.01-100g per g of the titanium compound is polymerized in the first-stage polymerization, and then propylene is polymerized in the same polymerization system to produce a propylene copolymer of a vinylalkane unit content of 0.05-10,000ppm by weight.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to method 1 for producing a propylene copolymer with excellent crystallinity.

Polyproblene is an excellent synthetic resin with high rigidity and mechanical strength, but it is a polymer with a relatively slow crystallization rate. Therefore, depending on the application field, 1. Problems include a decrease in rigidity due to low crystallinity after molding, and the formation of relatively large spherulites, resulting in poor transparency and loss of commercial value.

Therefore, several attempts have been made to improve the crystallinity and transparency of polypropylene. For example, the aromatic carboxylic acid alumina.

salt or sodium salt (Japanese Patent Publication No. 58-80829), aromatic carboxylic acid, aromatic phosphate metal salt, sorbitol, -rubank conductor (Japanese Patent Publication No. 65-124.60, Ukai, Showa) 58-12.9086) etc. is known to act as a nucleating agent for crystal nuclei (hereinafter referred to as a nucleating agent), thereby alleviating the above-mentioned problems. Among these nucleating agents, sorbitol derivatives exhibit excellent nucleating effects, but sorbitol derivatives bleed from the resin, causing roll stains during film formation, and strong odor during processing, which limits its use. . In addition, aluminum salts of aromatic carboxylic acids, which are commonly used, act as nucleating agents, but the effect of improving the transparency of polypropylene is very small, and many voids occur when formed into a film. In order to improve the transparency of polypropylene, it was proposed in Japanese Patent Publication No. 45-8248 to copolymerize eight components: propylene, an α-olefin having 4 to 18 carbon atoms, and 8-methyl butene-1.
However, the transparency of such a copolymer is unsatisfactory.

The present inventors conducted extensive studies in view of these drawbacks, and as a result, they discovered that the rigidity and transparency of polypropylene can be improved by copolymerizing vinylcycloalkane and propylene, leading to the present invention. That is, the present invention uses a catalyst system consisting of a titanium compound and an organoaluminum compound to: (1) polymerize a vinylcycloalkane having 6 or more carbon atoms;
Polymerization of propylene alone or copolymerization with ethylene is carried out in multiple stages, and the content of vinylcycloalkane units in the total polymer is o, o 5Wt ppm-110000W
tpI). Specifically, (1) the vinylcycloalkane is polymerized in the first step, and propylene alone or copolymerized with ethylene is performed in the second step.

(2) In the first step, propylene is polymerized alone or copolymerized with ethylene, and in the second step, the vinylcycloalkane is polymerized.

(3) In the first stage, propylene is homopolymerized and in the second stage
The present invention relates to a production method in which the vinylcycloalkane is polymerized in the eighth step, and the monoalkane of propylene is polymerized one or more times in the eighth step.

There is no particular limit to the content of the vinylcycloalkane polymer in the present invention, but in order to achieve the improvement effect without changing the inherent physical properties of polypropylene, the vinylcycloalkane unit content in the total polymer must be 0.05%. wtppm
~110000 WtI)p is required, preferably 0.5 wt ppm ~5000 wt ppm, more preferably 0.5 wt ppm ~1000 wt
It is ppm.

Specific compounds of the vinylcycloalkane used in the present invention include vinylcyclopentane, vinyl-8-methylcyclopentane, vinylcyclohexane, vinyl-2
-methylcyclohexane, vinyl-8-methylcyclohexane, vinylnorbornane, etc. Among these, vinylcycloalkanes having 8 or more carbon atoms are more preferred.

The polymerization direction of the vinylcycloalkane may be homopolymerization of the vinylcycloalkane or copolymerization with a small amount of other vinylcycloalkanes or α-olefins such as ethylene, propylene, butene, etc. As the polymerization solvent, the vinylcycloalkane monomer or a hydrocarbon compound such as butane, hexane, heptane, benzene, toluene, etc. is preferably used. The polymerization temperature is the same as the M polymerization of α-olefins using the usual Ziegler-Natsuta catalyst, and is 20 to 10
Polymerization is preferably carried out in a temperature range of 0°C. The polymerization amount of the vinylcycloalkane per 1f of titanium compound catalyst is not particularly limited, but is preferably in the range of 0.01 to 100F, more preferably 0.1 to 50F.

Propylene alone or copolymerized with ethylene (Bl is a polymerization method known in the art, i.e., slurry polymerization in a hydrocarbon solvent such as hexane or heptane, bulk polymerization in liquefied propylene, gas phase polymerization in propylene gas, etc.) The copolymerization of propylene and ethylene may be random copolymerization or block copolymerization.

The titanium compound catalyst used in the present invention is a Ziegler-Natsuta catalyst that provides an isotactic polymer,
Titanium trichloride catalysts commercially available from Toyo Stoffer Co., Ltd., Toyoho Titanium Co., Ltd., Marubeni Solvay Co., Ltd., etc. can be suitably used. Also, Japanese Patent Application Laid-Open No. 57-59916,
A catalyst in which a titanium compound is supported on a magnesium compound described in Japanese Patent No. 455-188408 and the like is also preferably used.

The organoaluminum compound used in the present invention is AzX
aRg-a (X: halogen atom alkoxy group, or hydrogen atom, R: alkyl group having 1 to 18 carbon atoms, a: 0
Alkylaluminum compounds represented by ≦a (the number 8) are preferable, and specific examples include AA, (C[a
)B, At(CHa)NCL.

AL(CHs)lBr, AA(CHa)s+(OC
zHa), Aj(CgHs)s, AA, (CgHs)
gcz, AA(CgHs)zBr, Az(C
s+Hs)g(OCgHsAz(CzHs)2(Country 4H
9), AA (CgHs) (Country 4H9) 2, At (CzH
s ) Czg, A/! (CaHs+)s, At(C
tHe ) gcz , Ken αsha At(CaHta ) ac
and mixtures thereof.

The amount of the organoaluminum compound to be used is 0.01 to 100 mol, preferably 0.1 to 50 mol, per 1f titanium atom, and preferably 0.01 to 100 E mol per 1 t of the total amount of the solvent and liquefied monomer. is 0.1~50
'millimol.

In addition, in order to improve the stereoregularity of the polymer during polymerization,
It is also possible to add electron donors such as carboxylic esters, phosphoric esters, and silicate esters.

The propylene copolymer of the present invention can be produced by injection molding, pressure molding,
Using well-known techniques such as vacuum forming, extrusion, blow molding, and stretching, it can be made into many types of products such as sheets, films, containers, fibers, etc.

In addition, the propylene copolymer of the present invention may contain all types of additives that are normally added to polypropylene, such as heat and light stabilizers, antistatic agents, carbon black, pigments, and flame retardants, as necessary. . Furthermore, other polymers such as low-density polyethylene, high-density polyethylene, polybutene, and εP rubber, and fillers such as mica and talc can be mixed and used.

EXAMPLES The present invention will be specifically explained below with reference to examples, but the present invention is not limited to these examples.

Note that the melt index, diffuse transmission luminosity (LSI), haze, gloss, [η], crystallization temperature, etc. shown in the examples were measured according to the following methods.

(1) Melt index Measured according to J　I　SK67.58.

(2) [η],.

Measurements were performed in tetralin at 185° C. using an Ubbelohde viscometer.

(8) Crystallization Temperature Measurement was performed using a differential scanning calorimeter (DSC) at different temperature reduction speeds of 4°C.

(4) Diffuse transmitted light intensity (LS1.) Measured using an LSI tester manufactured by Toyo Seiki Co., Ltd. (receives scattered transmitted light of 1.2' to 3.6 cm).

(5) Haze Measured according to ASTM D1008.

(6) Gross Measured according to ASTM D5B2-5BT.

(7) Total light transmittance Measured according to ASTM D1746-62T.

(8) Flexural modulus Press molded according to JISK 6.758 Thickness 5
．． ASTM D790-66 for 0 sm samples
Measured according to

Measurement samples for the optical properties (4) to (9) were made using the press plate shown in Figure 1, and the press temperature, pressure, time,
Conditions prepared according to JIS K6758 were used.

Example 1: 1.95 f of triethylaluminum, 1)-ethyl anisate 675 to dehydrated and purified n-hebutane 10-
6. N9 and a titanium compound catalyst synthesized according to Example 1 of JP-A-57-59916. Of was sequentially added, and then the temperature of this mixed solution was raised to 50° C. = Subsequently, 50 fnt of vinylcyclohexane was added, and vinylcyclohexane was polymerized for 15 minutes. Thereafter, the resulting polymer slurry was washed four times with 200 tRt of n-hebutane to remove unreacted vinylcyclohexane and cocatalysts triethylaluminum and ethyl p-anisate. Next, n-hebutane was washed from the activated slurry by vacuum distillation.
- Hebutane was removed to obtain 7.8y of polyvinylcyclohexane powder containing active catalyst. The amount of polyvinylcyclohexane polymerized per 1.f of titanium compound catalyst charged was o.soy.

The above vinylcyclohexane polymerization catalyst 1.0611 triethylaluminum 0.75fSp-methyl toluate 0
．． Using 1500 ml of 287f,n-hebutane, propylene was polymerized in a stainless steel autoclave with an internal volume of 5 tons at a pressure of 61'4 Adl gauge, a temperature of 70° C., and a hydrogen concentration of 1.5 VOZ% for 40 minutes. After the polymerization was completed, 50 mA of n-butanol was added to stop the polymerization.
The polymerization slurry was taken out, and the polymerization powder and solvent were separated by filtration. The polymer powder was washed with 500-IN hydrochloric acid, and then washed with methanol until the washing solution became neutral.

The salary was 1080f per 1f of catalyst. Further, its [η] was 1.98 di/f. The vinylcyclohexane content in this copolymer powder is 290 Wtppm, considering the amount of polymerization per titanium compound catalyst. B I T as a stabilizer was added to 100 parts by weight of this copolymer.
0.2 parts by weight, 0.05 parts by weight of calcium stearate, IrganoPl 010 (antioxidant manufactured by Ciba Gaiki Co., Ltd., tetrakis[methylene-8(8',5'-di-
0.05 part by weight of t-butyl-4-hydroxyphenyl)propionate comethane) was added and kneaded for 5 minutes with a heated roll at 190°C.

Next, melt using a hot press molding machine set at 280℃,
After applying pressure, it was cooled in a cooling press in which water at 30° C. was circulated to produce a pressed sheet with a thickness of 1 m+i. This press sheet had no odor at all, and when measured, haze, LSI, and gloss were 24.0%, 1.6%, and 100%, respectively. The crystallization temperature of this composition was 182.6°C.

Comparative Example 1 Propylene was homopolymerized under exactly the same conditions as in Example 1, using the titanium compound catalyst used in Example 1 but not polymerizing vinylcyclohexane. The physical properties of the obtained polypropylene are haze 60.0%, LSI 4
2.0%, gloss 73%, and crystallization temperature 119.0°C.

The difference in crystallization temperature between the propylene copolymer of Example 1 and the homopolypropylene of Comparative Example 1 is as large as 13.6" (), and the optical properties of the propylene copolymer of Example 1 are also comparable. This is superior to Example 1, demonstrating the excellent nucleation effect of the vinylcyclohexane polymer.

Examples 2 to 6 1 After adding 7.5 mmol of diethylaluminum chloride and 50.41 mmol of a titanium trichloride catalyst manufactured by Marubeni Solvay in sequence to 500 mmol of dehydrated and purified n-heptane, the mixed solution was heated to 60°C. Polymerization was carried out for 90 minutes while heating, and then adding 70% of vinylcyclohexane dropwise. As a result, a catalyst was obtained in which 1.09 F of vinylcyclohexane was polymerized per titanium trichloride catalyst If.

Using this catalyst and diethylaluminum chloride,
Propylene homopolymerization was carried out in the same manner as in Example 1 to obtain propylene copolymers shown in Table 1. The optical properties and flexural modulus values of these copolymers were measured in the same manner as in Example 1, and are shown in Table 1.

Comparative Examples 2 to 8 Examples 2 to 2 Vinylcyclohexane in Table 1
A propylene copolymer was obtained by changing the vinyl compound described above. Table 1 shows the optical properties and flexural modulus values of these copolymers.

The data in Table 1 show that the vinyl cyclohexane polymer exhibits the effect of improving the optical properties and the stiffness of polypropylene in a very small amount, and that the melting point of the homopolymer of the vinyl compound polymerized in the first stage and the copolymer No correlation was observed between the transparency of the polymer and the comparative examples showed that 8-methyl, butene-1 and 8-methyl pent-1 had a slight improvement effect. There is.

Example 7, Comparative Example 9 In the same manner as in Example 2, the random copolymers of propylene and ethylene shown in Table 2 were polymerized, and their optical properties were measured and listed in Table 2. By copolymerizing a small amount of vinylcyclohexane, the transparency of propylene and ethylene copolymers is significantly improved.

[Brief explanation of drawings]

FIG. 1 shows an outline of a press plate for measuring samples of optical properties. ■ indicates a 1m SUS plate, and ■ indicates an 1111I+ aluminum plate. Figure 1 Continuation of page 1

Claims (1)

[Claims] (1) A titanium compound and an organoaluminum compound,
Polymerization of a vinylcycloalkane having six or more carbon atoms and (B) propylene alone or in combination with ethylene are carried out in multiple stages using a catalyst system, and the vinylcycloalkane unit is contained in the entire polymer. Quantity crab, 0.05 wt
ppm to 10,000 wt ppm. A method for producing a propylene copolymer. 1. (2) A patent characterized in that the propylene copolymerization process according to claim 1 is characterized in that it consists of a two-stage polymerization in which the polymerization and polymerization of @1 stage A (2) is carried out, and the gate polymerization is carried out in the second stage. Method for producing polymers. (8) In the Western polymerization, the claim of the patent which specifically states that the vinyl cycloalkane is titanized and polymerized by 0.01 to 1001 to the compound 1f. The propylene Hokurai barrel making method is listed on the top of the box.