JPS63165415A - Production of crosslinked olefin block copolymer - Google Patents

Abstract

PURPOSE:To obtain the titled copolymer, a thermoplastic elastomer outstanding in strength, heat resistance and low-temperature impact resistance, by making a copolymer constituted of propylene homopolymer block and ethylene-propylene copolymer blocks using a specific catalyst followed by crosslinking with a crosslinking agent. CONSTITUTION:First, an olefin block copolymer constituted of (A) 15-45wt.% of propylene homopolymer block, (B) 5-25wt.% of ethylene-propylene two- component random copolymer block containing 3-20wt.% of ethylene, and (C) 50-70wt.% of ethylene-propylene two-component random copolymer block containing 20-40wt.% of ethylene with the component A accounting for 50-90wt.% of the components A plus B is made using a Ziegler type catalyst comprising (1) a solid composition comprising Mg, Ti and halogen as the essential components, respectively, (2) an electron donor and (3) an organoaluminum compound. Thence, this copolymer is crosslinked while kneading at <=230 deg.C together with an organic peroxide, divinyl compound and antioxidant, thus obtaining the objective copolymer with the content of hot-xylene insolubles 5-40wt.%.

Description

DETAILED DESCRIPTION OF THE INVENTION [Background of the Invention] Industrial Application Field The present invention relates to a novel method for producing a crosslinked propylene-ethylene block copolymer useful as an olefinic thermoplastic elastomer.

In recent years, expectations for flexible materials with excellent strength, heat resistance, and impact resistance at low temperatures have been increasing in the fields of automobile interiors, exterior parts, household organic product parts, electric wires, vibrators, and various sheets.

On the other hand, soft materials include polyvinyl chloride with plasticizers, ethylene-vinyl acetate copolymers, and ethylene-α-olefin copolymers, but their uses are limited due to poor heat resistance. The propylene-α-olefin random copolymer, which has excellent properties, lacks flexibility and also has poor impact resistance at low temperatures. On the other hand, vulcanized rubber is heat resistant,
Although it has excellent impact resistance, its use is severely limited due to workability during molding and difficulty in recycling.

Thermoplastic elastomers are beginning to be used as materials that satisfy these properties. Among various thermoplastic elastomers, polyolefin-based ones are being used in a wide range of fields because they have better weather resistance and chemical resistance than other thermoplastic elastomers, and their production costs are low.

BACKGROUND TECHNOLOGY AND PROBLEMS Olefinic thermoplastic elastomers are generally produced by a process consisting of melt-kneading ethylene-propylene rubber and polypropylene resin and, depending on the case, partially crosslinking them before or after kneading. For example, JP-A-47-18943, JP-A-48-26838, JP-A-49-53938, and JP-A-54-1386.
An example can be seen in the publication. However, to the best of the inventors' knowledge, these methods have been hindered by the increased cost associated with the blending process, which has hindered the expansion of demand, and on the other hand, the molecular design of the blend components has not necessarily been fully optimized. I have a quality problem.

On the other hand, instead of mechanically blending ethylene-propylene rubber and polypropylene resin, a method has been proposed in which both components are produced stepwise in a polymerization vessel using a two-stage polymerization method. It has the advantage of avoiding cost disadvantages compared to blends. Such a method is described, for example, in Japanese Patent Application Laid-open No. 55-80418 and Japanese Patent Laid-open No. 55-80418.
No. 7-10611, JP-A-57-10612, and JP-A-57-61012.

However, to the best of the inventors' knowledge, these methods also have problems. That is, JP-A-55-8041
According to the method disclosed in Publication No. 8, the tensile strength and elongation were insufficient, and the quality was not satisfactory. JP-A-57-10611 and JP-A-57-106
According to the method disclosed in Publication No. 12, the tensile strength and elongation were slightly improved, but not sufficiently, and the heat resistance was also not satisfactory. Also, JP-A-57-6101
According to the method disclosed in Publication No. 2, the improvement in tensile properties is insufficient, and at the same time, the polymerization temperature is low and large temperature changes are forced during polymerization, making stable production difficult due to heat removal problems. be.

[Summary of the invention]

Means for Solving the Problems In order to solve the problems of the prior art, as a result of repeated research, we have developed copolymer blocks (A), (B) and A crosslinked product with a specific gel fraction derived from a block copolymer obtained by linking (C) in a specific ratio has an excellent balance of tensile properties, heat resistance, processability, and product appearance. The present invention has been made based on the discovery that

Therefore, the method for producing a crosslinked olefin block copolymer according to the present invention is characterized by the following requirements.

(a) The catalyst used is a Ziegler type catalyst whose main components are a solid composition containing magnesium, titanium, and halogen as essential components, an electron donor, and an organoaluminum compound.

(b) With this catalyst, 15 to 45% by weight of the propylene homopolymer block (A) and ethylene-containing ff13
5 to 25% by weight of a propylene/ethylene binary random copolymer block (B) having a weight% or more and less than 20Tfrffi%, and a propylene/ethylene binary random copolymer block (C) having an ethylene content of 20 to 40% by weight and 96% by weight. 50
70% by weight, and the proportion of block (A) in block (A) and block (B) is 50 to 90% by weight.

(c) The obtained block copolymer is treated with an organic peroxide,
To obtain a crosslinked product having a content of heat xylene insoluble components of 5 to 40% by weight by kneading and crosslinking together with a divinyl compound and an antioxidant at a temperature of 230° C. or lower.

Effects of the present invention According to the present invention, a block copolymer having well-balanced properties as described above can be obtained.

The flexibility of the crosslinked olefin block copolymer obtained by the present invention has a JIS-A hardness of 98 to 70,
The flexural modulus is about 4000 to 400 kg/c-.

The olefinic block copolymer according to the present invention falls into the category of thermoplastic elastomers, and although it is crosslinked, it has the fluidity necessary for molding and can be molded into sheets and various other shapes. can do.

[Detailed description of the invention]

1. Catalyst The catalyst used in the present invention is a solid composition containing magnesium, titanium, and halogen as essential components, an electron donor, and an organoaluminum compound.

Solid Composition The solid composition is a highly active solid catalyst component containing magnesium, titanium and halogen as essential components. This solid catalyst may contain other elements or inorganic or organic compounds, particularly electron donor compounds, in addition to the above-mentioned essential components. The inclusion of electron donor compounds is particularly preferred. Furthermore, it may be diluted with an inorganic or organic diluent.

Such a catalyst component can be produced by the following method.

(1) Activated magnesium halide, a titanium compound and, if necessary, an electron donor compound,
A method by simultaneous or stepwise co-grinding or contact in a liquid state. A halogenating agent may be brought into contact during any of the steps (see Japanese Patent Application Laid-Open Nos. 53-45688 and 55-90510).

(2) A precipitate obtained by reacting a halogenating agent, a reducing agent, etc. with a homogeneous magnesium compound in the presence or absence of an electron donor is added with a titanium compound and, if necessary, an electron donor. A method by contacting a compound (JP-A-54-40293, JP-A-56-811, JP-A-58-183708, JP-A-58-183709).

(3) A method in which an organomagnesium compound such as a Grignard reagent is treated with a halogenating agent, a reducing agent, etc., and then brought into contact with an electron donor and a titanium compound (JP-A-52-14672, JP-A No. Showa 53-10098
6 publications, etc.).

Among these methods, method (2) is preferred.

Magnesium compounds used in preparing this solid catalyst component include magnesium oxide, magnesium hydroxide, hydroxymagnesium halide, magnesium cybaride, alkoxymagnesium halide,
Examples include allyloxymagnesium halide, dialkoxymagnesium, dialkylmagnesium, magnesium carboxylate, alkylmagnesium halide, dialkylmagnesium, and the like.

Examples of the titanium compound used in preparing this solid composition include titanium tetrahalide, alkoxytitanium halide, allyloxytitanium halide, alkoxytitanium, allyloxytitanium, and the like. Among these, titanium tetrachloride is particularly preferred. A molecular compound obtained by reacting these titanium compounds with an electron donor compound may also be used.

The essential halogen atoms of this solid composition are fluorine, chlorine, bromine and iodine or mixtures thereof, with chlorine being particularly preferred.

Electron donor compounds optionally used in this solid composition include esters of organic and inorganic acids, acid amides, acid halides, acid anhydrides, alkoxysilanes, ketones,
Oxygenated compounds such as ethers may be mentioned. As the acid, organic acids, especially aliphatic basic to dibasic carboxylic acids of about 01 to 08 and aromatic basic to dibasic carboxylic acids of about 07 to 01 are suitable, and the carboxyl group thereof As one of the functional derivatives, esters with monohydric or dihydric alcohols of about 01 to 012 are typical. The alcohol in this case may be an ether alcohol. Particularly preferred in the present invention are organic acid esters such as cellosolve acetate, butyl 0-propionylbenzoate, dihebutyl phthalate, and acid halides such as phthaloyl chloride.

The quantitative relationship of the constituent components of this solid composition is such that the Ti/Mg molar ratio is in the range of 1 x 10-2 to 1, and the halogen/Mg
The molar ratio is in the range of 0.5 to 4, and when an electron donor compound is used, the electron donor compound/Mg molar ratio is 1x1
It is preferably in the range of 0-2 to 1.

Electron Donor As the electron donor for improving the stereoregularity of the propylene polymer, the following (1) to (iv) are preferable.

(1) General formula (R4, R5 and R6 are hydrocarbon residues having about 1 to 20 carbon atoms, which may be the same or different, or hydrogen, X2 is a halogen atom, where e+f+g+h=4.0≦
an organosilicon compound represented by e≦3.0≦f≦3.1≦g≦4.0≦h≦3).

This compound can also be synthesized in-system. For example, a compound having a 5i-0-C bond can also be synthesized from phenyltrichlorosilane and an alkoxy-containing compound or alcohol.

Specific examples of (1) include ethyl silicate, butyl silicate, phenyl silicate, methyltriethoxysilane, ethyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, methyltriphenoxysilane, vinyltriethoxysilane, dimethyl Examples include dimethoxysilane, diethyldimethoxysilane, diphenyldimethoxysilane, phenylmethyldimethoxysilane, trimethylmethoxysilane, triphenylmethoxysilane, and chlorotrimethoxysilane.

(ii) Specific examples of the ester compound (11) include ethyl acetate, cellosolve acetate, methyl methacrylate, diethyl maleate, ethyl α-phenylisobutyrate, ethyl benzoate, ethyl 0-methoxybenzoate, diethyl phthalate, and phthalate. Examples include diheptyl acid (for others, see the electron donor for solid components mentioned above).

(1il) Specific examples of the ether compound (iil) include diisoamyl ether,
Examples include diphenyl ether, tetrahydrofuran, and 1,8-cineol. Ether esters such as cellosolve acetate can also be considered as specific examples of ether compounds.

(1v) Other electron donors Examples include peroxides such as dicumyl peroxide, phosphorus-containing compounds such as triethyl phosphite, and amine compounds such as 2°2.6.6-titramethylpiperidine.

Electron donor compounds can also be used in combination within and between each of the above groups.

Among these various electron donors, (i
) is an organosilicon compound.

Unlike the electron donor, which is an optional component for the solid catalyst component described above, this electron donor is used during polymerization to form a catalyst together with the solid composition - organoaluminum compound; Compound molar ratio ranges from 0.01 to 1.0, preferably 0.0
A range of 5 to 0.5 is appropriate.

Organoaluminum Compound The organoaluminum compound according to the present invention is a general formula in which R1, R2, R3, and R4 are hydrocarbon residues or hydrogen having about 1 to 20 carbon atoms, which may be the same or different, and X is a halogen atom. . a+b+C+d+e-3 and 0≦a
≦3.0≦b≦3.0≦C≦3.0≦d≦3.0≦e≦
Organoaluminum compounds represented by 3) are suitable.

Specific examples of such compounds include (a) trialkyl aluminum such as triethylaluminum, triisobutylaluminum, trihexylaluminum, and diethylaluminium, and (b) diethylaluminum monochloride, diisobutylaluminum monochloride, and ethylaluminum sesquis. chloride,
Alkyl aluminum halide such as ethyl aluminum dichloride, (c) alkyl aluminum halide such as diethylaluminium hydride, diisobutyl aluminum hydride, (d) diethylaluminum ethoxide, diethylaluminium butoxide, diethylaluminium phenoxy Examples include side-like alkyl aluminum alkoxides and allyloxides. These can be used alone or in combination of two or more.

The amount of J'fl used of the organoaluminum compound is preferably within the range of 0.1 to 1000 in terms of ff1f ratio to the solid composition.

2. Production of block copolymer The polymerization process according to the present invention carried out in the presence of the above catalyst consists of three steps (steps (a), (b) and (c)).

Although steps (a), (b), and (c) may be performed in any order, they are usually performed in the order of (a)-(b)-(c). Further, by making any of the above steps consist of two or more small steps, polymer blocks having different compositions can be produced in each small step.

(1) Step (a) Propylene alone is supplied to the polymerization system having the catalyst, and 15 to 45% by weight, preferably 15 to 35% by weight of the total polymerization amount is supplied.
An amount of polymer corresponding to % by weight, particularly preferably from 17 to 33% by weight, is formed.

The propylene homopolymer block (A) produced in step (a) is a highly crystalline element that contributes to imparting strength and heat resistance to the crosslinked block copolymer. physical properties are impaired. If it exceeds the above range, the characteristics such as flexibility, tensile properties, low-temperature impact resistance, and excellent appearance attributed to copolymer blocks (B) and (C) will be impaired.

(2) Step (b) Preferably, following step (a), a propylene/ethylene mixture is supplied to the polymerization system, so that the ethylene content is 3% by weight or more and less than 20% by weight, preferably 4 to 17% by weight, particularly preferably is 5 to 15% by weight of the binary random copolymer block (B) consisting of propylene and ethylene, 5 to 25% by weight, preferably 10 to 25% by weight, particularly preferably 10 to 22% by weight of the total polymerized amount. It is formed in an amount corresponding to %. The propylene/ethylene random copolymer block produced in step (B) has an intermediate composition between the block (A) described above and the block (C) described below, and contributes to improving the compatibility of both blocks. .

The good tensile properties and excellent appearance of the molded product of the crosslinked block copolymer according to the present invention are due to the presence of block (B), which improves the compatibility of each block and makes the morphology of the crosslinked block copolymer homogeneous. This is thought to be due to increased sex. Therefore, when the polymerization amount is less than the above-mentioned amount, poor appearance is often caused, and when it is more than the above-mentioned amount, the physical characteristics due to blocks (A) and (C) are impaired. In particular, in order to emphasize heat resistance, block (A) is used in an amount of 50 to 90% by weight of the total amount of block (A) and block (B).
It is important that the amount is preferably 50 to 80% by weight. If it is below this range, the heat resistance will be significantly lowered and there will be a practical problem.

In addition, as mentioned above, block (B) contributes to improving the compatibility of the other two blocks, and therefore, even if the ethylene content deviates from the above range, the appearance may be poor or the tensile properties may be deteriorated. cause a decline.

(3) Step (c) Preferably, following step (b), a propylene/ethylene mixture with a higher ethylene content is supplied to the polymerization system, so that the ethylene content is 120 to 40%, preferably 2.
The propylene/ethylene random copolymer block (C) of 5 to 35% by weight is formed in an amount corresponding to 50 to 70% by weight, preferably 50 to 65% by weight of the total polymerization amount. The propylene/ethylene random copolymer block produced in step (c) has low crystallinity or poor quality, contributes to imparting flexibility and low-temperature impact resistance, and has a polymerization amount below the above range. and these physical properties are impaired. If it exceeds the above range, the flexibility will be too low and the object of the present invention will be lost.

Furthermore, when the ethylene content is below the above range, isotactic polypropylene chains increase and flexibility and low-temperature impact resistance are lost. On the other hand, if it exceeds the above range, the tensile properties in particular deteriorate, which is not preferable.

The polymerization temperature in steps (a), (b), and (c) is 20 to
The temperature is about 80°C, preferably 50 to 70°C. The polymerization pressure is about 1 to 30 kg/cjG.

(4) Molecular Weight It is preferable to use hydrogen or the like as a molecular weight regulator in each step.

The molecular weight of the block copolymer is indicated by the average molecular weight of the copolymer blocks formed in each step, but MFR (A
STM-D-1238 (L)) is 0.02 to 50 (g
/10 minutes), preferably 0.05 to 20 (g/10 minutes), particularly preferably 0.1 to 15 (g/10 minutes). If it exceeds this range, the mechanical strength will not reach a practical level, while if it falls below this range, the viscoelastic properties in the molten state will deteriorate, making granulation molding difficult. The molecular weight of the copolymer block formed in each step is not particularly limited, but the copolymer block formed in step (c) (
The molecular weight of C) is generally equal to or larger than the molecular weight of the copolymer block formed in the other two steps.

(5) Polymerization method The copolymer according to the present invention can be produced by any of the batch, continuous, and semi-continuous methods. Also,
It is carried out by suspension polymerization or solution polymerization in heptane or other inert hydrocarbon.

In the second step and/or the third step, addition of an organoaluminum compound, change of hydrogen concentration, etc. can be performed.

3. Production of crosslinked product In the present invention, it is essential to crosslink the block copolymer produced by copolymerization.

The crosslinked product can be obtained by a method of kneading an organic peroxide as a crosslinking agent and a divinyl compound as a crosslinking aid in the coexistence of the mixture.

Preferred organic peroxides are high temperature decomposition type compounds;
,5-dimethyl72.5-di(t-butylperoxy)
Hexane, 2,5-dimethyl-2゜5-di(t-butylperoxy)hexyne-3,2,5-dimethyl-2,5
(benzoylperoxy)hexane, t-butylperoxyperbenzoate, dicumyl peroxide, di-t
-butyl peroxide, t-butylcumyl peroxide, diisopropylbenzene hydroperoxide, benzoyl peroxide, p-chlorobenzoyl peroxide, methyl ethyl ketone peroxide, di-t-butyl-di-peroxy phthalate, and the like.

Examples of the divinyl compound as a crosslinking aid include divinylbenzene, ethylene glycol dimethacrylate, and diallyl phthalate.

The amount of crosslinking agent and crosslinking aid used is an important factor since it greatly affects the degree of crosslinking. The preferred amount of crosslinking agent used is 0.
．． 05~0. 5 parts by weight, particularly preferably 0.08-0
．． 3 parts by weight, and the amount of crosslinking aid used is 0.05 to 1.
0flffi part, preferably 0.1 to 0.5 W part. If it is above this range, the degree of crosslinking will be too high and moldability will be significantly deteriorated, while if it is below this range, properties such as heat resistance cannot be exhibited.

The usual crosslinking method is a mechanical melt-kneading method.

For crosslinking by mechanical melting and melt-kneading, a melt-kneader such as a single-screw extruder, twin-screw extruder, Banbury mixer, etc. is used, and partial crosslinking is carried out at the stage of melt-kneading. The kneading temperature is 230℃ or less,
Preferably 160-220°C, particularly preferably 170-220°C
210°C. If the kneading temperature is too low, it will be difficult to melt the block copolymer. If it exceeds the above range, the polymer will deteriorate or abnormal crosslinking will proceed, resulting in a significant decrease in physical properties, which is not preferable.

Note that melt-kneading in advance at least in the absence of a cross-linking agent before cross-linking during mechanical melt-kneading may be effective in improving the appearance of the molded article.

Furthermore, it is essential to add an antioxidant during crosslinking.

Antioxidants are usually used in the presence of crosslinking agents and crosslinking coagents. Any commonly used phenol-based, sulfur-based, or phosphorus-based compounds can be used as the antioxidant.

The amount of antioxidant used is 0.05 to 0.5 parts by weight, preferably 0.1 to 0.3 parts by weight. When the content is below this range, the effect of the antioxidant is poor, leading to poor appearance of the molded product, which is thought to be caused by polymer deterioration or local crosslinking. On the other hand, if it exceeds this range, the effect of the antioxidant becomes excessive and the crosslinking efficiency decreases, which is not preferable.

The fact that the present crosslinked product produced by the above method is crosslinked and has excellent moldability is recognized by the gel fraction and MFR measured as a hot xylene insoluble component (the measurement method will be described later).

That is, the gel fraction of the present crosslinked product is 5 to 40% by weight, preferably 8 to 35% by weight, and more preferably 10 to 30% by weight. If the gel fraction is below the above range, the objective of the present invention, which is to improve heat resistance, cannot be achieved. Also,
If it exceeds the above range, moldability will be impaired.

The melt flow properties of this crosslinked product are as follows: ASTM-D-1238 (L
), the desired melt flowability is 0.01
-30, preferably 0.02-20, more preferably 0
．． 02-10. It is.

If the flowability is below the above range, molding becomes difficult. If it exceeds the above range, the gel fraction is usually lowered, making it impossible to improve heat resistance, which is not preferable.

Paraffinic or naphthenic process oil can be added to the crosslinked product of the present invention for the purpose of improving melt flowability and flexibility. The amount added is 0
-20 parts by weight, preferably 0-15 parts by weight. Excessive use is undesirable, as it may cause deterioration of mechanical properties and bleed-out of process oil.

Further, the crosslinked product of the present invention can be made of commonly used carbon,
Fillers such as various pigments, talc, and glass fibers can be blended and used. On the other hand, it is also possible to control the physical properties by blending propylene-based or ethylene-based resins. Further, additives such as a heat stabilizer, an antioxidant, an ultraviolet absorber, and an antistatic agent can be added as necessary.

Experimental Examples In the following Examples and Comparative Examples, the test methods used for evaluation are as follows.

(1) MFRCz/10 minutes): ASTM-D-1238
(L) (2) Hardness [-]: JIS-6301A tie (3)
Tensile strength kg/cd) and elongation [%]: J Is-
ni-6501 (4) Izot impact strength [kg-cm/cffI]:
ASTM-D-256 (with notch) (5) Gel fraction [wt%] Content of hot xylene-insoluble components: Wrap 1 g of sample in an 80-mesh stainless steel wire mesh, place it in a Soxhlet extractor, and heat it with boiling xylene. de1
After 0 hours of extraction, the ratio of the unextracted portion to the prepared sample is determined.

(6) Compression set [%]: JIS-ni-6501
(7) Gloss [%]: ASTM-D-523 (8) Gloss change rate [%): ASTM-D-523° Compared to the gloss of a sheet press-molded at 210°C, a Teflon sheet with a rough surface was It is the rate of change in gloss after applying a load of 30 kg/cj for 20 seconds at °C, and is an index of heat resistance.

In the following experimental examples and comparative examples, the additives used during kneading and crosslinking are as follows.

(1) Irganox 1010: Tetrakis [methylene-3-(3',5'-di-t-
Butyl-4'-hydroxyphenyl)propionate comethane (2) Antage BHT: Yoshitomi Pharmaceutical Co., Ltd. 2.6-di-t-butyl-p-cresol (3) BKs Nitto Kasei Kogyo Co., Ltd. Calcium stearate (4) Kayahexa AD : 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, manufactured by Kayaku Nury Co., Ltd. Example-1 l) Synthesis of solid catalyst component In a 1-liter flask that was sufficiently purged with nitrogen, thoroughly dehydrated. , 200 ml of deoxygenated n-heptane were introduced, then 0.2 mol of MgCl2, Ti(OC4H9)4
0.4 mol of was introduced, and the mixture was reacted at 95°C for 2 hours.

After the reaction was completed, the temperature was lowered to 40° C., and then 30 ml of methylhydropolysiloxane was introduced and reacted for 3 hours.

After the reaction was completed, the produced solid component was washed with n-heptane.

100 ml of n-hebutane was introduced into a 0.5 liter flask which had been sufficiently purged with nitrogen, and 0.09 mol of the above solid component was introduced in terms of Mg atoms. Then, SiC140-
15 mol was introduced at 30°C for 30 minutes and reacted at 70°C for 1 hour. In addition, phenyltriethoxysilane 0
．． 012 mol was added thereto and reacted at 70°C for 1 hour. After the reaction was completed, it was washed with n-heptane.

Next, 0.009 mol of diheptyl phthalate was introduced at 30°C for 30 minutes, and the mixture was reacted at 50°C for 1 hour. After the reaction was completed, it was washed with n-hebutane.

Finally, 425ml of TiCl was added and reacted at 100°C for 2 hours. After the reaction is finished, wash with n-hebutane,
A solid composition was obtained.

The Ti loading rate of the solid composition thus obtained was 2
．． It was 4% by weight.

2) 35 liters of heptane, 0.50 g of the above solid component, 8.8 g of triethylaluminum, and diphenyldimethoxysilane in the presence of propylene gas in a 100 liter stainless steel reactor equipped with a polymerization stirring blade.
8 g was charged. Propylene was charged at a constant rate while maintaining the temperature inside the polymerization reactor at 65°C. The amount of propylene charged is 3. When the weight reached 2 kg, charging of propylene was stopped and the temperature was maintained at 65° C. for 10 minutes (block (A) above). Next, ethylene was charged at a constant rate, and when the amount charged reached 0.095 kg, the charging of ethylene was stopped, and the temperature was maintained at 65° C. for 2 minutes (block (B) above). After the polymerization of block (B) is completed, the residual propylene is quickly released to normal pressure, and the internal temperature is lowered to 65%.
While maintaining the temperature at °C, a propylene/ethylene mixed gas containing 32% by volume of ethylene was charged at a constant rate. When the amount of mixed gas charged reached 4.4 kg, charging of mixed gas was stopped, and the temperature was maintained at -65° C. for 10 minutes (block (C) above).

After adding butanol to the obtained block copolymer slurry and treating it at 60°C, the catalyst residue was removed by washing thoroughly with water. This slurry was steam stripped and then dried to obtain a product of 4.5 dens.

Table 1 shows the composition and ratio of each block constituting the obtained block copolymer.

After blending 0.05 parts by weight of Irganox 1010, 0.05 parts by weight of Antige BIT, and 0.1 parts by weight of BK into the obtained block copolymer, the mixture was granulated at 210°C using a 40φ single-screw extruder. It was made into pellets. Next, 0.14 parts by weight of Kayahexa AD, 0.13 parts by weight of divinylbenzene, and 0.2 parts by weight of Irganox 1010 were added to the pellets.
Blend 0TIlffi part and use a 40φ single screw extruder to make 170
The mixture was kneaded and crosslinked at ℃. The MFR of the obtained crosslinked product is 0.07
g/10 minutes, and the gel fraction was 24ffif1%.

This crosslinked product was molded into a sheet with a thickness of 0.3 mm at 200° C. using a 45φ T die extrusion molding machine, and the physical properties of the sheet were evaluated. The results are shown in Table 1.

Comparative Example-1 In Example-1, the kneading temperature during kneading and crosslinking was set to 240°C.
A crosslinked product was obtained in exactly the same manner as in Example 1, except that the method was carried out in Example 1. This crosslinked product was formed into a sheet in the same manner as in Example 1, but the sheet had numerous bumps and had an extremely poor appearance, making it impossible to evaluate the physical properties of the sheet.

Comparative Example-2 In Example-1, the kneading temperature during kneading and crosslinking was set to 200°C.
and Irganox 1 in the blending at the time of kneading and crosslinking.
A crosslinked product was obtained in exactly the same manner as in Example-1 except that 010 was not blended. Although this crosslinked product was molded into a sheet in the same manner as in Example 1, the sheet properties could not be evaluated because many spots were generated on the sheet.

Comparative Examples-3 and 4 In Example-1, 0.55 parts by weight of divinylbenzene (Comparative Example-3) or 0.60 parts by weight of Kayahexa AD (Comparative Example-4) were added in the blending during kneading and crosslinking. A crosslinked product was obtained in exactly the same manner as in Example-1. This crosslinked product was molded into a sheet in the same manner as in Example 1, but many bubbles were generated on the sheet, making it impossible to evaluate the physical properties of the sheet.

Comparative Example-5 In Example-1, 0.60 parts by weight of Kayahexa AD and 0.5 parts by weight of divinylbenzene were added during kneading and crosslinking.
A crosslinked product was obtained in exactly the same manner as in Example-1 except that 5 parts by weight was added. This crosslinked product does not flow at all and therefore the MF
R was not measurable and the gel fraction was 55% by weight.

This crosslinked product was molded into a sheet in the same manner as in Example 1, but the sheet surface became uneven and only a sheet with extremely poor appearance was obtained.

Comparative Example-6 In Example-1, copolymer was produced in exactly the same manner as in Example-1, except that the amount of propylene charged during the production of block (A) was 3.3 kg, and block (B) was not produced. The composite was manufactured, crosslinked, and sheet molded. The results are shown in Table 1.

Example 2 l) Synthesis of solid catalyst component 2 liters of n-hebutane, which had been sufficiently dehydrated and deoxidized, was introduced into a 10 liter flask which had been sufficiently purged with nitrogen, and then 2 mol of MgCl2 and Ti (OC4H9)4 were added. 4
A molar amount of the mixture was introduced, and the reaction was carried out at 95° C. for 2 hours. After the reaction was completed, the temperature was lowered to 40'C, and then 300ml of methylhydropolysiloxane was introduced, and the reaction was allowed to proceed for 3 hours. After the reaction was completed, the produced solid component was washed with n-hebutane.

1 liter of n-hebutane was introduced into a 5 liter flask that had been sufficiently purged with nitrogen, and 0.9 mol of the above solid component was introduced in terms of Mg atoms. Then, 3 moles of 5iC11.5
The reaction was carried out at 0°C for 30 minutes and then at 70°C for 1 hour. Further, 0.12 mol of phenyltriethoxysilane was added, and the mixture was reacted at 70° C. for 1 hour. After the reaction is complete, n-
Washed with hebutane.

Then, 0.09 mole of phthaloyl chloride was added at 30'C.
The mixture was introduced for 0 minutes and reacted at 50°C for 1 hour. After the reaction was completed, it was washed with n-hebutane.

Finally, 250 ml of TiC14 was added and reacted at 100°C for 2 hours. After the reaction was completed, it was washed with n-heptane to obtain a solid composition.

The Ti loading rate of the solid composition thus obtained was 2
．． It was 4% by weight.

2) In the presence of propylene gas, 35 liters of heptane, 0.50 g of the above solid components, 3.7 g of l-ethylaluminum, and 2,2,6 1.1 g of ゜6-titramethylpiveridine was charged.

While maintaining the temperature inside the polymerization reactor at 75°C, propylene was charged at a constant rate, and the amount of propylene charged was 2.2 kg.
At this point, the charging of propylene was stopped (block (A) above). Subsequently, ethylene was charged at a constant rate, and when the amount charged reached 0.055 kg, the charging of ethylene was stopped, and the temperature was maintained at 75° C. for 2 minutes (block (B) above). After completing the polymerization of block (B), the residual propylene was quickly released to normal pressure, and the internal temperature was lowered to 60°C.
While maintaining the temperature at °C, a propylene/ethylene mixed gas containing 33% by volume of ethylene was charged at a constant rate.

When the amount of mixed gas charged reached 3.9 kg, charging of mixed gas was stopped and the mixture was maintained at 60° C. for 20 minutes (block (C) above).

After adding butanol to the obtained block copolymer slurry and treating it at 60°C, the catalyst residue was removed by washing thoroughly with water. 700 g of process oil PW380 manufactured by Idemitsu Chemical Co., Ltd. and 2.5 g of Irganox 1010 were added to this slurry, and this slurry was steam stripped and dried to obtain 5.2 kg of a product.

Table 1 shows the composition and ratio of each block constituting the obtained block copolymer.

After blending 0.1 part by weight of BK into the obtained block copolymer, it was granulated into pellets at 210°C using a 40φ single-screw extruder. Next, add 0.1 of Kayahexa AD to the pellet.
7 parts by weight, 0.16 parts by weight of divinylbenzene, 0.200 parts by weight of Irganox 1010,
Kneading and crosslinking were carried out at 170°C using a 0φ single screw extruder. The VFR of the obtained crosslinked product was 0.02 g/10 minutes, and the gel fraction was 30' parts by weight.

This crosslinked product was molded into a sheet with a thickness of 0.3 fin at 200° C. using a 45φ T die extrusion molding machine, and the physical properties of the sheet were evaluated. The results are shown in Table 1.

Comparative Example-7 In Example-4, the ethylene content of the propylene/ethylene mixed gas at the time of manufacturing block (C) was 56% by volume.
A copolymer was produced, crosslinked, and sheet-molded in exactly the same manner as in Example 4 except that the following was changed. The results are shown in Table 1.

Comparative Example-8 In Example-4, the ethylene feeding timing during the production of block (B) was changed to 15 minutes after the start of propylene charging during the production of block (A), and the ethylene charging rate was changed to 30%. A copolymer was produced, crosslinked, and sheet-molded in exactly the same manner as in Example 4, except that the viscosity of the copolymer was lowered to . The results are shown in Table 1.

Claims (1)

[Claims] A method for producing a crosslinked olefin block copolymer, which is characterized by meeting the following requirements. (a) The catalyst used is a Ziegler type catalyst whose main components are a solid composition containing magnesium, titanium, and halogen as essential components, an electron donor, and an organoaluminum compound. (b) With this catalyst, 15 to 45% by weight of the propylene homopolymer block (A) and 3% by weight of ethylene
5 to 25% by weight of the propylene/ethylene binary random copolymer block (B) with an ethylene content of 20 to 40% by weight or more, and 50 to 50% of the propylene/ethylene binary random copolymer block (C) with an ethylene content of 20 to 40% by weight. 70% by weight, and the proportion of block (A) in block (A) and block (B) is 50 to 90% by weight. (c) By kneading and crosslinking the obtained block copolymer with an organic peroxide, a divinyl compound, and an antioxidant at a temperature of 230°C or lower, the content of thermally xylene-insoluble components is reduced to 5 to 40% by weight. To obtain a certain crosslinked product.