JP2880732B2 - Method for producing polyolefin resin composition - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing a polyolefin resin composition. More specifically, the present invention relates to a method for producing a crosslinked polyolefin resin composition modified with various compounds.

[Conventional technology]

A cross-linking reaction is performed for the purpose of improving the physical properties of polyolefin. However, α-olefins such as polypropylene originally have a higher priority for depolymerization of the main chain than the crosslinking reaction, so that crosslinking is not caused by simply decomposing peroxides or simply generating radicals by irradiation with radiation. Rather, the decomposition proceeds and the molecular weight only decreases. For this reason, it is usual to graft a monomer which undergoes a crosslinking reaction by hydrolysis of alkoxyvinylsilane or the like onto a polyolefin, followed by crosslinking (for example, JP-A-58-117244). In addition, grafting of compounds containing various polar groups has been performed for the purpose of imparting adhesiveness, coatability and the like to polyolefin.

[Problems to be solved by the invention]

A polymer obtained by grafting an alkoxyvinylsilane onto a polyolefin has a certain effect on improving the physical properties by crosslinking the polyolefin.However, the process of synthesizing the graft polymer is complicated, and the physical properties due to the main chain cleavage due to an essential problem of the reaction. Is difficult to avoid, and it is also difficult to introduce compounds containing various polar groups. on the other hand,
It is also known to introduce vinyl silane into the main chain and then crosslink with water (for example, US Pat. No. 3,223,686),
The cross-linking reaction with water is relatively difficult to proceed and takes a long time, and the molded product is deformed due to exposure to a high temperature, and the operation is complicated.
Further, the method of modifying a polyolefin using a radical initiator such as a peroxide has the same problem as that occurring during crosslinking, such as reducing the molecular weight of the polyolefin itself.

[Means for solving the problem]

The present inventors have diligently searched for a method for producing a crosslinked polyolefin modified with various compounds by solving the above problems, and have completed the present invention.

That is, the present invention provides a compound represented by the general formula H ₂ C = CH- (CH ₂ ) _n -SiH _p R
_3-p (where n is 0 to 12, p is 1 to 3, R is 1 to 12 carbon atoms)
Hydrocarbon residues. ) Or a copolymer of alkenyl silane and olefin in which H of 1 to 3 Si-H bonds of the alkenyl silane is substituted with chloro, is irradiated with a C-C-containing compound, A method for producing a polyolefin resin composition, comprising subjecting a polyolefin resin composition to a heat treatment in the presence of a C-containing C = O compound, and a general formula H ₂ C = CH- (CH ₂ ) _n -SiH _p R _3-p (formula Middle n is 0-1
2, p is 1 to 3 and R is a hydrocarbon residue having 1 to 12 carbon atoms. )
After irradiating a mixture of a polyolefin and an alkenylsilane represented by the formula or a copolymer of an alkenylsilane and an olefin in which 1 to 3 Si-H bonds of the alkenylsilane are substituted with chloro, C-containing C = C compound, containing C =
A method for producing a polyolefin resin composition, comprising performing heat treatment in the presence of an O compound.

In the present invention, a copolymer of alkenylsilane and olefin can be obtained by polymerizing olefin and alkenylsilane using a so-called Ziegler-Natta catalyst, which comprises a transition metal catalyst and an organometallic compound.For example, U.S. Pat. Examples are disclosed. Further, a graft copolymer obtained by graft-polymerizing a polyolefin by subjecting it to heat treatment with alkenylsilane in the presence of a radical polymerization initiator such as peroxide may be used. The alkenylsilane used in the present invention has a general formula
_{H 2 C = CH- (CH 2} ) n -SiH p R 3-p ( wherein n is 0 to 12, p is 1 to 3, R is a hydrocarbon residue having 1 to 12 carbon atoms.) Are represented by Specific examples thereof include vinyl silane, allyl silane, butenyl silane, pentenyl silane, and compounds in which H of 1 to 3 Si—H bonds of these monomers is substituted with chloro. As the olefin of the general formula H ₂ C = CH-R (wherein R is hydrogen or a hydrocarbon residue having 1 to 12 carbon atoms.) Can be exemplified compounds represented by, in particular ethylene, propylene, butene -1, pentene-1,
In addition to α-olefins such as hexene-1, 2-methylpentene, heptene-1, and octene-1, styrene or a derivative thereof is also exemplified.

In the present invention, as the copolymer of olefin and alkenylsilane, a catalyst comprising TiCl ₃ and triethylaluminum described in the above-mentioned U.S. Patent can be used, but more preferably, a catalyst which gives a polyolefin with various high activities developed thereafter is more preferable. Is used.

As the polymerization method, in addition to the solvent method using an inert solvent, a bulk state polymerization method and a gas phase polymerization method can be adopted. Here, as the catalyst comprising the transition metal compound and the organometallic compound, a titanium halide is preferably used as the transition metal compound, and an organoaluminum compound is preferably used as the organometallic compound. For example, titanium trichloride obtained by reducing titanium tetrachloride with metallic aluminum, hydrogen or organic aluminum, modified with an electron donating compound, an organic aluminum compound, and if necessary, an electron donating compound such as an oxygen-containing organic compound. A catalyst system consisting of: a transition metal compound catalyst obtained by supporting a titanium halide on a carrier such as a magnesium halide or a carrier obtained by treating them with an electron-donating compound; an organoaluminum compound; and, if necessary, an oxygen-containing organic compound. A catalyst system comprising an electron-donating compound, or a reaction product of magnesium chloride and an alcohol, is dissolved in a hydrocarbon solvent, and then treated with a precipitant such as titanium tetrachloride to render the catalyst insoluble in the hydrocarbon solvent. Treat with an electron-donating compound such as an ester or ether, and then treat with titanium halide. Examples include catalyst systems comprising a transition metal compound catalyst and an organoaluminum compound, and, if necessary, an electron-donating compound such as an oxygen-containing organic compound. Ziegler-Natta catalysts and P
olymerization by John Boor Jr (Academic Press), Jo
urnal of Macromorecular Sience Reviews in Macromol
ecular Chemistry and Physics, C24 (3) 355-385 (19
84), and C25 (1) 578-597 (1985)). Alternatively, the polymerization can be carried out using a catalyst comprising a transition metal catalyst and an aluminoxane which are soluble in a hydrocarbon solvent.

Here, as the electron donating compound, oxygen-containing compounds such as ether, ester, orthoester and alkoxysilicon compound can be preferably exemplified, and alcohol, aldehyde, water and the like 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. The aluminoxane is an oligomer to a polymer obtained by reacting the above-mentioned organic aluminum with water or water of crystallization.

Here, the polymerization ratio of the alkenylsilane and the olefin is not particularly limited, but is usually about 0.001 to 30 mol%, preferably 0.1 to 10 mol%, in terms of mixing with the polyolefin.

The molecular weight of the polymer is not particularly limited, but is preferably about the same as or less than the molecular weight of the polyolefin to be mixed and used.

The method for grafting the alkenylsilane to the polyolefin is not particularly limited, and the method and conditions generally used for the graft copolymerization can be used.The method is usually heating to the decomposition temperature of the radical initiator or higher in the presence of the polyolefin and the alkenylsilane used. Can be easily graft-copolymerized.

The polyolefin used in the present invention, the general formula H ₂ C = CH-R (wherein R is C1-12 hydrogen or C
Hydrocarbon residues. ), Specifically, α-olefins such as ethylene, propylene, butene-1, pentene-1, hexene-1, 2-methylpentene, heptene-1 and octene-1, and styrene or a derivative thereof. Or a random copolymer of each other, or a so-called block produced by first copolymerizing with one olefin alone or a small amount of another olefin, and then copolymerizing two or more olefins. Copolymers and the like are exemplified. In particular, it is effective to provide the method of the present invention to an α-olefin such as propylene or a copolymer thereof, which is difficult to crosslink alone. Methods for producing these polyolefins are already known and various brands are available on the market. In addition, except that alkenylsilane is not used, it can be produced in the same manner as in the above-mentioned method for producing a polymer of olefin and alkenylsilane.

In the present invention, the alkenyl silane and olefin copolymer is usually mixed with an alkenyl silane-free polyolefin, or only an alkenyl silane copolymer without an alkenyl silane-containing polyolefin is used. Can be. The mixing ratio of the alkenylsilane and olefin copolymer when used as a mixture depends on the alkenylsilane content in the copolymer, but the ratio of the copolymer in the mixture is usually preferably 0.1 wt% or more. It is preferable that the alkenyl silane is present in the polyolefin at about 0.005 wt% in the irradiation with radiation. It is possible to use various known additives at the time of mixing, and there is no particular limitation.

The crosslinking reaction by irradiation with radiation is usually carried out after molding into a desired shape, but when the degree of crosslinking is relatively low, molding may be carried out after the crosslinking reaction.

As the radiation used in the present invention, α rays, β rays,
Examples include γ-rays, X-rays, neutron rays, etc., and particularly γ-rays and electron beams can be preferably used.
Irradiation on the order of rad is common, and irradiation beyond this has no particular effect. Below this irradiation, there is almost no effect. The temperature at the time of irradiation is not particularly limited, but is usually from room temperature to lower temperature. However, it is not necessary to cool to a low temperature. Irradiation can be performed in an inert gas atmosphere or in the presence of oxygen. However, irradiation in an inert gas atmosphere is often preferable in terms of reproducibility and the like. After irradiation, the polyolefin is heated in the presence of a C 含 C-containing compound or a C 含 O-containing compound. The heating temperature is usually 30 ° C
Above, preferably 50 ° C. or higher-the heat resistant temperature of the polyolefin ~ or less, when the molded product is irradiated with radiation, usually at a temperature below the melting point, when molded after irradiation, for molding. The heating and melting operation can also serve as a heat treatment. The heat treatment time varies depending on the heating temperature, but is usually several minutes to several hours. C-containing used here
Examples of the C compound or the C 含 O-containing compound include, for example, aldehydes and ketones as the C 含 O-containing compound. Aldehydes such as proaldehyde and benzaldehyde, acetone, methyl ethyl ketone,
Methyl propyl ketone, diethyl ketone, 2-hexanone, 3-hexanone, cyclohexanone, biacetyl,
Examples include acetophenone and benzophenone. Including C
= C compound has 2 to 20 carbon atoms, usually 5 to 5 carbon atoms
20 unsaturated aliphatic hydrocarbons or alicyclic hydrocarbons can be exemplified, pentene, hexene, heptene, octene,
Examples thereof include olefins such as cyclohexene, dienes such as butadiene, isoprene, and octadiene, and those in which one or more of hydrogens of these compounds are substituted with a polar group such as carboxylic acid, carboxylic acid ester, nitro, and sulfonic acid. . When heated, these compounds are usually present in a liquid state or a gaseous state. However, when the compound is heated in a gaseous state, unreacted C 含 C-containing compounds or C 含 O-containing compounds after heating are removed. Is simple. [Examples] The present invention will be further described below with reference to examples.

Experimental Example 1 A vibrating mill equipped with four grinding pots each 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 45 ml of α, α, α-trichlorotoluene were added and pulverized for 40 hours. 300 g of the co-ground product thus obtained was placed in a 51 flask, and titanium tetrachloride, 1.5 l and toluene 1.
5 l was added, the mixture was stirred at 100 ° C. for 30 minutes, and then the supernatant was removed. Again, 1.5 l of titanium tetrachloride and 1.5 l of toluene were added, and the mixture was stirred at 100 ° C. for 30 minutes, and then the supernatant was removed. Thereafter, the solid content was repeatedly washed with n-hexane to obtain a transition metal catalyst slurry. When a part was sampled and the titanium content was analyzed, the titanium content was 1.9 wt%.

In a pressure-resistant glass autoclave having an inner volume of 200 ml, under a nitrogen atmosphere, 40 ml of toluene, 50 mg of the above transition metal catalyst, 0.128 ml of diethylaluminum chloride, and methyl p-toluate
0.06 ml and 0.20 ml of triethylaluminum were added, and then 4.0 g of vinylsilane was injected.
cm ² and polymerized at 70 ° C. for 2 hours under constant pressure. Thereafter, the slurry was taken out and filtered and dried to obtain 43 g of a powder. Intrinsic viscosity (hereinafter abbreviated as η) measured with tetralin solution at 135 ° C, 10 ° C using differential thermal analyzer
When the melting point and the crystallization temperature were measured as the maximum peak temperature by raising or lowering the temperature at / min, the obtained powder had η of 1.61 dl / g, a melting point of 156 ° C., and a crystallization temperature of 118.
It was a crystalline polypropylene having a temperature of ° C. According to elemental analysis, it contained 1.8 wt% of a vinylsilane unit.

To the obtained copolymer, a phenol-based stabilizer 10/10000
Weight ratio (to polypropylene copolymer) and calcium stearate 15 / 10,000 weight ratio added to thickness 2mm and 1mm 1cm
× 5 cm sheet.

Experimental Example 2 A sheet was obtained in the same manner as in Experimental Example 1, except that a copolymer (allyl silane content: 1.3 wt%) obtained by using allyl silane instead of vinyl silane was used.

Experimental Example 3 A copolymer of vinylsilane and butene-1 was obtained in the same manner as in Experimental Example 1, except that butene-1 was used instead of propylene. 10 parts of this copolymer and 90 parts of a block copolymer of propylene and ethylene (ethylene content 8 wt%) were mixed to obtain a sheet in the same manner as in Experimental Example 1.

Examples 1, 2, 3, 4 and Comparative Examples 1, 2, 3, 4 An electron beam (750 kV) was applied to the sheets obtained in Experimental Examples 1 and 2 by 2 Mrad.
Irradiation was performed, and the sheet obtained in Experimental Example 2 was irradiated with γ-rays at 2 Mrad. Then, the sheet is put in a saturated steam atmosphere of acrylic acid for 100
Heat treatment was performed at 10 ° C. for 10 minutes (Experimental Examples 1, 2, and 3 correspond to Experimental Examples 1, 2, and 3). Similarly, a heat treatment was performed at 100 ° C. for 10 minutes in a saturated vapor atmosphere of benzaldehyde (Experimental Example 4 used the sheet of Experimental Example 1). With the physical properties of the material thus treated, Examples 1,2,3,
Physical properties of a sample similar to that of Example 4 are shown as Comparative Examples 1, 2, 3, and 4.

Here, the sheet was placed in a # 100 mesh wire mesh container, extracted with boiling tetralin for 24 hours, the extraction residue was calculated, and this was evaluated as the degree of crosslinking. The reaction amount of acrylic acid or benzaldehyde was calculated from an infrared absorption spectrum.

Yield strength ASTM D638 kg / cm ² (23 ℃) Flexural rigidity ASTM D747-63 kg / cm ² (23 ℃) Izod (with notch) Impact strength kg ・ cm / cm ASTM D256-56 (23 ℃, -10 ℃) Comparative Example 5 The procedure of Example 1 was repeated, except that the physical properties were measured as it was after irradiation with the electron beam. The yield strength was 390, the flexural rigidity was 13,500, the degree of crosslinking was 60, and the amount of reaction was as follows. Is 0
However, the degree of crosslinking is small and the improvement of physical properties is not sufficient.

Comparative Example 6 The same procedures as in Example 3 were carried out except that the physical properties were measured as they were after the irradiation with the electron beam. The yield strength was 305, the bending rigidity was 11,000, and the Izod impact strength was 6.
5, 3.5, the degree of cross-linking was 25, and the reaction amount was 0. The degree of cross-linking was small and the improvement in physical properties was not sufficient.

〔The invention's effect〕

By carrying out the method of the present invention, the reaction of crosslinking and modifying the polyolefin can proceed very easily, and is extremely industrially significant.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08F 230: 08)

Claims (2)

(57) [Claims] 1. A compound of the general formula H ₂ C ＝ CH— (CH ₂ ) _n —SiH _p R _3-p (where n is 0 to 12, p is 1 to 3, and R is a hydrocarbon having 1 to 12 carbon atoms) After irradiating the alkenyl silane represented by the formula (I) or a copolymer of an alkenyl silane and an olefin in which 1 to 3 Si-H bonds of the alkenyl silane are substituted with chloro, the C-containing A method for producing a polyolefin resin composition, comprising performing heat treatment in the presence of a C compound and a C = O-containing compound. 2. A compound of the general formula H ₂ C ＝ CH— (CH ₂ ) _n —SiH _p R _3-p (where n is 0 to 12, p is 1 to 3, and R is a hydrocarbon having 1 to 12 carbon atoms) Irradiating the alkenyl silane represented by the formula (1) or a mixture of a polyolefin and a copolymer of an alkenyl silane and an olefin in which 1 to 3 Si-H bonds of the alkenyl silane are substituted with chloro. A method for producing a polyolefin resin composition, comprising performing heat treatment in the presence of a C-containing C = C compound and a C-containing O compound.