JPH10101806A - Production of polyolefin resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To readily obtain the subject composition free from discoloration without leaving an unreacted cross-linking agent by heating, melting and blending a specific olefin-based copolymer in the presence of a specific compound. SOLUTION: (A) A copolymer (A1 ) of an alkenylsilane such as a compound of the formula H2 C=CH-(CH2 )n -SiHp R3-p (R is a 1-12C hydrocarbon group; (n) is 0-12; (p) is 1-3) and an α-olefin such as a compound of the formula H2 C=CH-R or a mixture of the component A1 and a crystalline olefin is heated, melted and blended in the presence of (B) an alkaline (earth) metal alkoxy compound and (C) a hindered aminebased compound. The amounts of the components B and C used are, for example, 0.00001-1wt.% and 0.001-1wt.% based on the component A, respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 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 polyolefin resin composition, which comprises heating and melting and mixing a polyolefin obtained by copolymerizing a specific monomer in the presence of a specific compound.

[0002]

2. Description of the Related Art Various crosslinked products of polyolefins have been used for the purpose of improving the physical properties of polyolefins or the flowability during foaming. As the crosslinking method, a method of mixing and crosslinking at the time of molding by mixing a crosslinking agent, a method of crosslinking by irradiating radiation after molding, or a method of crosslinking by treating with boiling water after molding (for example,
-117244) and the like.

[0003]

The method using a cross-linking agent has a problem that an unreacted cross-linking agent remains, and the method of performing a cross-linking by performing a treatment after molding has a problem that it is complicated. There is a need for a method that does not have any problem with the agent. As such a method, a method of heating and melting and mixing a copolymer of alkenylsilane and α-olefin in the presence of a hydrosilylation catalyst (for example, JP-A-5-5035) is known. The polyolefin resin composition had problems such as coloring.

[0004]

Means for Solving the Problems The present inventors diligently searched for a method for producing a polyolefin resin composition which solved the above problems, and completed the present invention.

That is, the present invention relates to a method of heating a copolymer of an alkenylsilane and an α-olefin or a mixture of the copolymer and a crystalline polyolefin in the presence of an alkali metal or alkaline earth metal alkoxy compound and a hindered amine compound. This is a method for producing a polyolefin resin composition, which is characterized by melt-mixing.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, a copolymer of alkenylsilane and α-olefin can be produced by a bulk polymerization method or a gas phase polymerization method in addition to a solvent method using an inert solvent. Further, as the catalyst used for the production, it is common to use a catalyst comprising a transition metal compound and an organometallic compound, and titanium halide is preferably used as the transition metal compound, and an organoaluminum compound is preferably used as the organometallic compound. .

Specifically, titanium tetrachloride obtained by reducing titanium tetrachloride with metallic aluminum, hydrogen or organic aluminum is modified with an electron donating compound, an organic aluminum compound, and if necessary, an oxygen-containing organic compound. A catalyst system comprising an electron donating compound such as a compound, or a carrier such as magnesium halide or a transition metal compound catalyst obtained by supporting a titanium halide on a carrier obtained by treating them with an electron donating compound, and an organoaluminum compound; If necessary, a catalyst system comprising an electron-donating compound such as an oxygen-containing organic compound, or a reaction product of magnesium chloride and an alcohol is dissolved in a hydrocarbon solvent,
Then, it is insolubilized in a hydrocarbon solvent by treating with a precipitant such as titanium tetrachloride, and if necessary, treated with an electron-donating compound such as an ester or ether, and then treated with a titanium halide. Examples of the catalyst system include a transition metal compound catalyst, an organic aluminum compound, and, if necessary, an electron donating compound such as an oxygen-containing organic compound. (For example, various examples are described in the following literature: Ziegler-Natta Catalystsand P
olymerization by John Boor Jr. (Academic Press), J
ournal of Macromolecular Science Reviews in Macrom
olecular Chemistry and Physics, C24 (3) 355-385 (198
4) and C25 (1) 578-597 (1985)).

Alternatively, the polymerization can be carried out using a catalyst comprising a transition metal catalyst soluble in a hydrocarbon solvent and an aluminoxane.

As the electron-donating compound, oxygen-containing compounds such as ethers, esters, orthoesters and alkoxysilicon compounds can be preferably exemplified. In addition, alcohols, aldehydes, water and the like can also be used.

As the organoaluminum compound, trialkylaluminum, dialkylaluminum halide,
Alkyl aluminum sesquihalides and alkyl aluminum dihalides can be used. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, and a hexyl group, and examples of the halide include chlorine, bromine, and iodine. Aluminoxane, which is an oligomer to a polymer obtained by reacting the above-mentioned organoaluminum with water or water of crystallization, can also be used.

In the present invention, as the alkenylsilane, those having at least one Si—H bond are preferably used, for example, a compound represented by the following general formula (Formula 1):

[0012]

Embedded image H ₂ CＨCH— (CH ₂ ) _n —SiH _p R _3-p (where n is 0 to 12, p is 1 to 3, and R is 1 to 12 carbon atoms)
Hydrocarbon residues. ), Specifically, vinyl silane, allyl silane, butenyl silane, pentenyl silane, or a compound in which H of Si—H bond in some of these monomers is substituted with chloro.

The α-olefin is a compound represented by the following general formula (Formula 2):

[0014]

Embedded image H ₂ C = CH—R (wherein R is hydrogen or a hydrocarbon residue having 1 to 12 carbon atoms), specifically, ethylene, propylene,
In addition to α-olefins such as butene-1, pentene-1, hexene-1, 4-methylpentene, heptene-1, and octene-1, styrene or its derivatives can be exemplified.

Here, the polymerization ratio of alkenyl silane and α-olefin is usually 0.001
About 30 mol%, preferably 0.01 to 20 mol%.

The molecular weight of the polymer is not particularly limited.
The molecular weight is determined according to the purpose. In terms of improvement of physical properties, it is better that the molecular weight is relatively high.
The limiting viscosity number measured with a tetralin solution at 5 ° C is 0.2 to
Generally, it is about 10 dl / g, preferably about 0.5 to 5.0 dl / g.

A graft polymer obtained by graft-polymerizing an alkenylsilane onto a polyolefin can also be used for the purpose of the present invention. In this case, the method for grafting the alkenylsilane onto the polyolefin is not particularly limited. The methods and conditions used for polymerization are available,
Usually, the graft copolymerization can be easily carried out by heating the polyolefin and alkenylsilane to be used in the presence of a radical initiator such as peroxide to a temperature not lower than the decomposition temperature of the radical initiator.

The polyolefin used in the present invention can be produced by carrying out polymerization without using alkenylsilane in the above-mentioned method for producing a copolymer of alkenylsilane and α-olefin. As mentioned above, they are already known, and various brands are also available on the market. The polyolefin is not particularly limited, and a copolymer of an α-olefin and ethylene or another monomer may be used in addition to a homopolymer of an α-olefin. That is, a random copolymer or a block copolymer can be used.

In the present invention, the ratio of the alkenylsilane / α-olefin copolymer to the polyolefin is 1 / 100,000 parts by weight or more based on 1 part by weight of the polyolefin. , Preferably 1 / 10,000 parts by weight or more. Here, there is no particular upper limit on the ratio of the alkenylsilane and α-olefin copolymer. That is,
A copolymer of alkenylsilane and α-olefin can be used alone.

In the present invention, a copolymer of an alkenylsilane and an α-olefin, or a mixture of the copolymer and a crystalline polyolefin, is heated and melt-mixed in the presence of an alkali metal or alkaline earth metal alkoxy compound and a hindered amine compound. Here, examples of the alkali metal or alkaline earth metal include lithium, sodium, potassium, rubidium, cesium, beryllium, magnesium, calcium, strontium, and barium. The alkoxy group is not particularly limited,
Methoxy, ethoxy, propoxy, n-butoxy, se
c. -Butoxy, tert. -An alkoxy group having an aliphatic hydrocarbon residue such as butoxy, pentanoxy, hexanoxy, heptanoxy, octanoxy, cyclohexanoxy, or phenoxy, 4-methylphenoxy, 2,6-di-tert-butyl-4-methylphenoxy, etc. And an alkoxy group having an aromatic hydrocarbon residue. Further, alkoxy groups derived from alcohols such as benzyl alcohol, ethylene glycol, diethylene glycol, polyethylene glycol, ethylene glycol monomethyl ether, propylene glycol, dipropylene glycol, polypropylene glycol, and propylene glycol monomethyl ether can also be preferably exemplified.

In the present invention, the amount of the alkali metal or alkaline earth metal alkoxy compound used may be a catalytic amount, but is usually a copolymer of alkenyl silane and α-olefin or a copolymer of the alkenyl silane and α-olefin. It is used in an amount of 0.00001 to 1% by weight, preferably 0.0001 to 0.5% by weight, based on the polyolefin mixture.

The hindered amine compound used in the present invention is not particularly limited.
-Piperidyl carbonate, bis- (2,2,6,6-
Tetramethyl-4-piperidyl) sebasate, bis-
(N-methyl-2,2,6,6-tetramethyl-4-piperidyl) sebasate, bis- (1,2,2,6,6-
Pentamethyl-4-piperidyl) -2- (3,5-di-
tert. -Butyl-4-hydroxybenzyl) -2-
n-butylmalonate, poly {[6- (1,1,3,3
-Tetramethylbutyl) imino-1,3,5-triazine-2,4-diyl] [(2,2,6,6-tetramethyl-4-piperidyl) imino] hexamethylene [(2
2,6,6-tetramethyl-4-piperidyl) iminol]}, tetrakis (2,2,6,6-tetramethyl-
4-piperidyl-1,2,3,4-butanetetracarboxylate, 1,1 ′-(1,2-ethanediyl) bis (3,3,5,5-tetramethylpiperazinone), dimethylsuccinate Polymer with 4-hydroxy-
2,2,6,6-tetramethyl-1-piperidineethanol, (Mixed 2,2,6,6-tetramethyl-
4-piperidyl / tridecyl) -1,2,3,4-butanetetracarboxylate, (Mixed1,2,2,
6,6-pentamethyl-4-piperidyl / tridecyl)
-1,2,3,4-butanetetracarboxylate, M
fixed @ 2,2,6,6-tetramethyl-4-piperidyl / β, β, β ′, β′-tetramethyl-3,9-
[2,4,8,10-tetraoxospiro (5,5) undecane] diethyl} -1,2,3,4-butanetetracarboxylate, Mixed {1,2,2,6,6
-Pentamethyl-4-piperidyl / β, β, β ′, β ′
-Tetramethyl-3,9- [2,4,8,10-tetraoxospiro (5,5) undecane] diethyl} -1,
2,3,4-butanetetracarboxylate and the like can be exemplified, and the amount used is usually 0.001 to 1 with respect to a copolymer of alkenylsilane and α-olefin or a mixture of the copolymer and crystalline polyolefin. % By weight, preferably 0.005 to 0.5% by weight.

In the present invention, the above-mentioned alkenylsilane-α-olefin copolymer and crystalline polyolefin are heated and melt-mixed in the presence of an alkali metal or alkaline earth metal alkoxy compound and a hindered amine compound. After all the components are mixed, the mixture is put into an extruder or a twin-screw kneader, and is heated and melt-kneaded. The contact temperature is about 150 to 300 ° C., and the contact time is about 0.05 to 20 minutes.

At the time of mixing, if necessary, in addition to the hindered amine compound, an antioxidant, a heat stabilizer, a weathering agent, an ultraviolet absorber, a radiation resistant agent, an antistatic agent, a crystal nucleating agent, an inorganic filler, a lubricant, Of course, it is also possible to add various additives usually used for olefin polymers, such as a plasticizer, a neutralizing agent, a pigment and a colorant. Further, auxiliary materials such as elastomers can be added to improve mechanical properties. Further, for the purpose of adjusting the molecular weight of the resulting polyolefin resin composition, upon mixing, a compound that generates a radical can also be added, a normal radical generator,
For example, benzoyl peroxide, di-t-butyl peroxide, dicumyl peroxide, acetyl peroxide, lauroyl peroxide, perbenzoic acid, t-butyl perbenzoate, 2,5-dimethyl-
Peroxides such as 2,5-di-t-butylperoxyhexane and azo compounds such as azobisisobutyronitrile can be used.

The amount of these compounds to be added is 0.00001 to 100% with respect to the copolymer of alkenylsilane and α-olefin or the mixture of the copolymer and the crystalline polyolefin.
It is about 0.1% by weight.

[0026]

The present invention will be further described with reference to the following examples.

In the examples, the melt flow index (hereinafter referred to as MI) was measured according to ASTM-D1238.
(230 ° C.). The measurement of bending rigidity is A
Based on STM-D747-63 (20 ° C).

Example 1 (Preparation of catalyst) A vibration mill equipped with four 4-liter crushing pots containing 9 kg of hard balls having a diameter of 12 mm was prepared. 300 g of magnesium chloride, 112 ml of diisobutyl phthalate and 60 ml of titanium tetrachloride were put in each pot under a nitrogen atmosphere, and pulverized for 40 hours. 300 g of the pulverized material thus obtained is placed in a 5-liter flask,
3 L of toluene was added, and the mixture was stirred at 110 ° C. for 30 minutes, and then the supernatant was removed. Again, 3 liters of toluene was added, the mixture was treated at 80 ° C. for 30 minutes, and the supernatant was removed.
Thereafter, the solid content was repeatedly washed with n-hexane to obtain a transition metal catalyst slurry. When a part of the titanium was sampled and analyzed, the titanium content was 2.2% by weight.

(Copolymerization reaction of propylene and vinyl silane) In a polymerization vessel having an inner volume of 70 liters, n-
0.70 g of the above transition metal catalyst slurried with 1 liter of hexane, 2.08 ml of propyltriethoxysilane
Then, 9.0 ml of triethylaluminum was added, 28.5 kg of propylene and 0.13 kg of vinylsilane were added, and 100 Nl of hydrogen was injected, followed by polymerization at 70 ° C for 2 hours. During the polymerization, hydrogen was fed sequentially so that the hydrogen concentration in the system became constant. After the polymerization, unreacted propylene was purged, and the powder was taken out.
0.2 kg of the copolymer was obtained.

The intrinsic viscosity number (hereinafter referred to as [η]) of this polymer measured in a tetralin solution at 135 ° C. is 1.
33 dl / g, molecular weight distribution M measured by GPC
w / Mn was 5.1. Further, when the silicon content was measured by fluorescent X-ray and converted to the vinylsilane content, the content was 0.14 mol% of the vinylsilane unit.

(Production and Evaluation of Resin Composition) The above method was applied to 100 parts by weight of polypropylene powder (TJH (L-Ash) manufactured by Mitsui Toatsu Chemicals, Inc.) having [η] of 1.87 dl / g. 5 parts by weight of the propylene / vinylsilane copolymer obtained in the above, potassium-tert. 0.1 part by weight of butoxide is added, followed by dimethyl succinate polymer with 4-hydroxy-2,2,2.
6,6-tetramethyl-1-piperidineethanol (TINUVIN 622LD, manufactured by Ciba-Geigy)
1 part by weight, 0.1 parts by weight of Irgafos 168 (manufactured by Ciba-Geigy) as an antioxidant, and 0.05 parts by weight of calcium stearate as a hydrochloric acid scavenger were added. Revolution 7
The mixture was melted and kneaded at 0 rpm and a temperature of 220 ° C. for 0.5 minute to obtain pellets.

The pellet had an MI of 3.3 g / 10 min. Using a differential scanning calorimeter (hereinafter, referred to as DSC), the crystallization temperature (hereinafter, referred to as Tc) and melting point (hereinafter, referred to as Tm) of the pellet, and 125.
When the value of the isothermal half-crystallization time (hereinafter referred to as t1 / 2) at ° C. was measured, Tc was 123.8 ° C.
m was 163.2 ° C. and t1 / 2 was 0.5 minute. In comparison with Comparative Example 1 shown below, both Tc and Tm increased and t1 / 2 became shorter with the progress of the crosslinking reaction.
The obtained pellets were not colored.

Then, using the above-mentioned pellet, a thickness of 1 mm
Was prepared, and the flexural rigidity was measured. The value of the flexural rigidity was 19,900 kg / cm ² .

Example 2 The procedure of Example 1 was repeated except that Irgafos 168 (manufactured by Ciba-Geigy) was not added. The resulting pellet had an MI of 4.6 g / 10 min and a Tc of 122.6.
° C and Tm were 162.0 ° C and t1 / 2 was 0.6 minutes. As in Example 1, Tc, T
An increase in m was observed, and t1 / 2 became shorter. No coloring was observed in the obtained pellets. The bending stiffness of the injection sheet was 19100 kg / cm ^2.
Met.

Comparative Example 1 The procedure of Example 1 was repeated except that no catalyst was added.
Although no coloring was observed in the obtained pellets, MI was 3.2 g / 10 min, Tc was 115.0 ° C., and Tm was 16
1.7 ° C., t1 / 2 was 1.1 minutes, and the crosslinking reaction did not proceed. The value of the bending rigidity of the injection sheet was 15,600 kg / cm ² .

Comparative Example 2 Example 1 except that 0.001 part by weight of tris (triphenylphosphine) rhodium chloride was added as a catalyst.
As a result, the MI of the obtained pellet was 2.4 g.
/ 10 min, Tc and Tm are 122.6 ° C., respectively, and 1
At 62.8 ° C., t1 / 2 was 0.6 minutes, and an increase in Tc and Tm and a decrease in t1 / 2 with the progress of the crosslinking reaction were observed. However, yellow-brown coloring was observed in the pellets.
The bending stiffness of the injection sheet is 18
It was 800 kg / cm ² .

Comparative Example 3 The same procedure as in Comparative Example 2 was carried out except that Irgafos 168 (manufactured by Ciba-Geigy) was not added. The resulting pellet had an MI of 2.8 g / 10 min and Tc and Tm of 1 each.
21.7 ° C., 162.6 ° C., t1 / 2 was 0.6 minutes, and the rise of Tc and Tm and t1 with the progress of the crosslinking reaction
A reduction of / 2 was observed. However, yellow-brown coloring was observed in the pellets. Further, the value of the bending rigidity of the injection sheet was 18,700 kg / cm ² .

Comparative Example 4 The procedure of Example 1 was repeated except that TINUVIN 622LD (manufactured by Ciba-Geigy) was not added. The resulting pellets had an MI of 1.0 g / 10 min and Tc and Tm of 124. 9 ° C., 163.6 ° C., t1 / 2 is 0.
It was 4 minutes, and an increase in Tc and Tm and a reduction in t1 / 2 with the progress of the crosslinking reaction were observed. However, Comparative Example 2,
In 3, the pellets were slightly yellow colored, though not as much as when tris (triphenylphosphine) rhodium chloride was used as a catalyst. The value of the bending stiffness of the injection sheet was 19,800 k.
g / cm ² .

[0039]

By carrying out the method of the present invention, the crosslinking reaction can proceed very easily, and the resulting polyolefin resin composition has no coloring, has excellent physical properties, and is extremely valuable industrially. is there.

Claims (1)

[Claims] An alkenyl silane and an α-olefin copolymer, or a mixture of the copolymer and a crystalline polyolefin, is heated and melt-mixed in the presence of an alkali metal or alkaline earth metal alkoxy compound and a hindered amine compound. A method for producing a polyolefin resin composition, comprising: