JP2901735B2 - Method for producing modified polyolefin particles - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a novel process for producing particulate modified polyolefins. More specifically, the present invention relates to a novel method for producing particulate modified polyolefin using polyolefin particles oxidized in the gas phase.

BACKGROUND OF THE INVENTION Various methods have conventionally been proposed as a method for modifying a polyolefin with an ethylenically unsaturated group-containing monomer such as styrene.

For example, a method of irradiating a polyolefin with an energy beam such as an electron beam and then contacting it with an ethylenically unsaturated group-containing monomer, dissolving the polyolefin and the ethylenically unsaturated group-containing monomer in an organic solvent, There are known a method in which a reaction is carried out in the presence of a substance, and a method in which an ethylenically unsaturated group-containing monomer is reacted with a polyolefin melted by a kneading device or the like.

Under such technical background, when a modified polyolefin is produced by reacting a vinyl monomer with a polyolefin, a dispersion in which the polyolefin is dispersed in an aqueous solvent is prepared as the polyolefin, and the polyolefin in the dispersion is prepared. Use of an oxidized polyolefin prepared by oxidizing the compound with an organic peroxide has been proposed (see JP-A-58-93730). By pre-oxidizing the polyolefin in this way, it becomes easier to introduce a vinyl monomer.

However, in this method, the oxidation reaction is performed in an aqueous solvent, and the oxygen concentration in the aqueous medium needs to be considerably increased in order to efficiently perform the oxidation reaction. Therefore,
In this method, it is necessary to use a pressure-resistant reactor such as an autoclave, which is disadvantageous in terms of equipment, and it is actually quite difficult to perform a continuous oxidation reaction using such a device. There is also a problem in terms of gender.

OBJECTS OF THE INVENTION An object of the present invention is to provide a novel method for modifying polyolefin particles with an ethylenically unsaturated group-containing monomer.

More specifically, an object of the present invention is to provide a novel method for efficiently modifying polyolefin particles with an ethylenically unsaturated group-containing monomer to produce highly uniform modified polyolefin particles.

SUMMARY OF THE INVENTION A method for producing a modified polyolefin particle according to the present invention comprises:
A mixture of the polyolefin particles (A) subjected to the gas phase oxidation treatment and the ethylenically unsaturated group-containing monomer (B) is subjected to an inert gas phase condition under which the olefin particles (A) can substantially maintain the particle state. It is characterized by heating with.

In the present invention, when preparing modified polyolefin particles as described above, polyolefin particles (A) oxidized in the gas phase are used. By oxidizing the polyolefin particles in the gas phase in this way, the oxidizing treatment can be performed without using a reaction device such as an autoclave which requires extremely high pressure resistance. Moreover, in the present invention, since both the oxidation treatment step and the modification step following the oxidation treatment step are performed in the gas phase, both steps can be performed continuously.

Furthermore, by blending the modified polyolefin particles thus obtained with another resin, a molded article having excellent mechanical properties such as impact resistance can be prepared.

Next, the method for producing the modified polyolefin particles of the present invention will be specifically described.

In the method for producing modified polyolefin particles of the present invention, polyolefin particles (A) that have been subjected to a gas phase oxidation treatment are used.

The method for producing the polyolefin particles used in the present invention is not particularly limited, but it is preferable to employ the method described below.

Polyolefin particles having the above properties can be obtained, for example, by polymerizing or copolymerizing an α-olefin having 2 to 20 carbon atoms.

Examples of such α-olefins include ethylene,
Propylene, butene-1, pentene-1, 2-methylbutene-1, 3-methylbutene-1, hexene-1, 3-
Methylpentene-1,4-methylpentene-1,3,3-
Dimethylpentene-1, heptene-1, methylhexene-1, dimethylpentene-1, trimethylbutene-1,
Ethylpentene-1, octene-1, methylpentene
1, dimethylhexene-1, trimethylpentene-1,
Ethylhexene-1, methylethylpentene-1, diethylbutene-1, propylpentene-1, decene-1,
Α-olefins such as methylnonene-1, dimethyloctene-1, trimethylheptene-1, ethyloctene-1, methylethylheptene-1, diethylhexene-1, dodecene-1, and hexadodecene-1.

Among these, it is preferable to use an α-olefin having 2 to 8 carbon atoms alone or in combination,
It is particularly preferred to use a combination of ethylene and propylene.

The polyolefin particles used in the present invention have the above α
The repeating unit derived from an olefin is usually at least 50 mol%, preferably at least 80 mol%, particularly preferably at least 100 mol%;
Contains mol%.

Further, the polyolefin particles have the α
-In addition to the repeating unit derived from an olefin, it may have a repeating unit derived from another compound polymerizable with the α-olefin.

Other compounds used herein include, for example, chain polyene compounds and cyclic polyene compounds.

These polyene compounds are polyenes having two or more conjugated or non-conjugated olefinic double bonds,
Examples of such chain polyene compounds include 1,4-hexadiene, 1,5-hexadiene, 1,7-octadiene,
Examples thereof include 1,9-decadiene, 2,4,6-octatriene, 1,3,7-octatriene, 1,5,9-decatriene and divinylbenzene.

Examples of the cyclic polyene compound include 1,3-cyclopentadiene, 1,3-cyclohexadiene, 5-ethyl-1,3-cyclohexadiene, 1,3-cycloheptadiene, dicyclopentadiene, and dicyclohexadiene. , 5
-Ethylidene-2-norbornene, 5-methylene-2-
Norbornene, 5-vinyl-2-norbornene, 5-isopropylidene-2-norbornene, methylhydroindene, 2,3-diisopropylidene-5-norbornene,
Examples include 2-ethylidene-3-isopropylidene-5-norbornene and 2-propenyl-2,5-norbornadiene.

Further, in producing the above-mentioned polyolefin particles, a cyclic monoene may be used. Examples of such a cyclic monoene include cyclopropene, cyclobutene, cyclopentene, cyclohexene, 3-methylcyclohexene, cycloheptene, cyclooctene, Monocycloalkenes such as cyclodecene, cyclododecene, tetracyclodecene, octacyclodecene and cycloeicosene; norbornene, 5-methyl-2-norbornene,
Ethyl-2-norbornene, 5-isobutyl-2-norbornene, 5,6-dimethyl-2-norbornene, 5,5,6-
Bicycloalkenes such as trimethyl-2-norbornene and 2-bornene; 2,3,3a, 7a-tetrahydro-4,7-methano-1H-indene and 3a, 5,6,7a-tetrahydro-
Tricycloalkenes such as 4,7-methano-1H-indene;
1,4,5,8-Dimethano-1,2,3,4,4a, 5,8,8a-Octahydronaphthalene and, in addition to these compounds, 2-methyl-1,4,5,8- Dimethano-1,2,3,4,4a, 5,8,8a-octahydronaphthalene, 2-ethyl-1,4,5,8-dimethano-1,2,
3,4,4a, 5,8,8a-octahydronaphthalene, 2-propyl-1,4,5,8-dimethano-1,2,3,4,4a, 5,8,8a-octahydronaphthalene, 2-hexyl-1,4,5,8-dimethano-
1,2,3,4,4a, 5,8,8a-octahydronaphthalene, 2-stearyl-1,4,5,8-dimethano-1,2,3,4,4a, 5,8,8a- Octahydronaphthalene, 2,3-dimethyl-1,4,5,8-dimethano-1,2,3,4,4a, 5,8,8a-octahydronaphthalene,
2-methyl-3-ethyl-1,4,5,8-dimethano-1,2,3,
4,4a, 5,8,8a-octahydronaphthalene, 2-chloro-
1,4,5,8-dimethano-1,2,3,4,4a, 5,8,8a-octahydronaphthalene, 2-bromo-1,4,5,8-dimethano-1,2,3,
4,4a, 5,8,8a-octahydronaphthalene, 2-fluoro-1,4,5,8-dimethano-1,2,3,4,4a, 5,8,8a-octahydronaphthalene and 2, Tetracycloalkenes such as 3-dichloro-1,4,5,8-dimethano-1,2,3,4,4a, 5,8,8a-octahydronaphthalene; hexacyclo [6,6,1,1 ^3.6 , 1 ^10.13 , 0 ^2.7 , 0 ^9.14 ] Heptadecene-4, pentacyclo [8,8,1 ^2.9 , 1 ^4.7 , 1 ^11.18 ,
0,0 ^3.8, 0 ^12.17] heneicosene -5, octacyclo [8,8,1 ^2.9, 1 ^4.7, 1 ^11.18, 1 ^13.16, 0,0 ^3.8, 0 ^12.17] cyclic monoene such as poly cycloalkene -5 like docosenoic Compounds can be mentioned.

Furthermore, in producing the above-mentioned polyolefin particles, styrene and substituted styrene can also be used.

The polyolefin particles used in the present invention are obtained, for example, by polymerizing or copolymerizing the above-mentioned α-olefin in the presence of a catalyst. This polymerization reaction or copolymerization reaction can be carried out in a gas phase (gas phase method) or in a liquid phase (liquid phase method).

The polymerization reaction or copolymerization reaction by the liquid phase method is preferably performed in a suspended state so that the polyolefin particles to be produced can be obtained in a solid state.

As a solvent used in the polymerization reaction or the copolymerization reaction, an inert hydrocarbon can be used.
Further, an α-olefin as a raw material may be used as a reaction solvent.

In producing the polyolefin particles used in the present invention, the above polymerization or copolymerization employs a gas phase method, or a method in which a reaction is performed in a liquid phase using an α-olefin as a solvent, and then the gas phase method is combined. Or the like.

In the method in which the liquid phase method and the gas phase method are combined, an inert hydrocarbon or an α-olefin as a raw material is used as a reaction solvent, and after the α-olefin is prepolymerized in the presence of a specific catalyst, the gas is vaporized. The α-olefin is further polymerized in the phase.

Examples of the inert hydrocarbon used in the solvent include propane, butane, n-pentane, i-pentane,
Aliphatic hydrocarbons such as n-hexane, i-hexane, n-heptane, n-octane, i-octane, n-decane, n-dodecane and kerosene; fats such as cyclopentane, methylcyclopentane, cyclohexane and methylcyclohexane Cyclic hydrocarbons; aromatic hydrocarbons such as benzene, toluene and xylene; and halogenated hydrocarbon compounds such as methylene chloride, ethylene chloride and chlorobenzene.

Further, as the above catalyst, preferably, a catalyst component [A] containing a transition metal of Groups IVA, VA, VIA, VIIA and VIII of the Periodic Table of the Elements, such as titanium, zirconium, hafnium and vanadium. And an organometallic compound catalyst component [B] of Groups I, II, and III of the periodic table, such as an organoaluminum compound having at least one Al-carbon bond in the molecule. use.

The catalyst component [A] can be prepared by blending an electron donor [C] (inside donor) in addition to the above components.

As the catalyst component [A], the periodic table IVA
A catalyst containing a transition metal atom belonging to Group III or VA is preferred, and among these, a catalyst component containing at least one atom selected from the group consisting of titanium, zirconium, hafnium and vanadium is particularly preferred.

Other preferred catalyst components [A] include a catalyst component containing a halogen atom and a magnesium atom in addition to the above-mentioned transition metal, and a group having a conjugated electron at a transition metal atom of Groups IVA and VA of the periodic table. And a catalyst component containing a compound coordinated with

The catalyst component [A] used in preparing the polyolefin particles in the present invention may be present in the reaction system in a solid state during the polymerization reaction or the copolymerization reaction as described above, or may be a carrier or the like. It is preferred to use a catalyst which has been prepared so that it can be present in the solid state by being supported on.

Such a catalyst component [A] is disclosed in JP-A-55-135.
No. 102, No. 55-135103, No. 56-67311 and Japanese Patent Application No.
Nos. 56-181019 and 61-21109.

The organometallic compound catalyst component [B] used together with the catalyst component [A] in producing the crystalline polyolefin polymer particles in the present invention includes, for example, an aluminoxane, an organic aluminum compound and a reaction of water. The obtained organoaluminum compound or the organoaluminum compound obtained by reacting an aluminoxane solution with water or an active hydrogen-containing compound can be used.

The organometallic compound catalyst component [B] may further contain an electron donor [C] (outside donor) in addition to the above components.

In preparing the polyolefin particles in the present invention, a prepolymerization is carried out prior to the main polymerization using the catalyst as described above.

After the preliminary polymerization, the above-mentioned polyolefin particles can be prepared by performing the main polymerization in the gas phase. The polymerization temperature during the prepolymerization is usually −40 to 80 ° C., and the polymerization temperature during the main polymerization using the above catalyst is usually −50.
The polymerization is carried out at a temperature of ~ 200 ° C and a pressure within the range of normal pressure ~ 100 kg / cm ² .

In the method for producing such polyolefin particles, the technique described in Japanese Patent Application No. 63-294066 can be used.

For example, the polyolefin particles produced as described above usually have a particle form in which crystal parts and amorphous parts are distributed in a sea-island manner. Further, the crystal part is made of a crystalline polyolefin, particularly a polypropylene-based resin,
By using polyolefin particles whose amorphous part is made of ethylene propylene random copolymer rubber, a composition excellent in impact resistance can be obtained.

For example, the melt flow rate measured at 230 ° C. according to ASTM D 1238 of the polyolefin particles prepared as described above is usually 0.1 to 100 g / 10 minutes, preferably 1 to 50 g / 10.
Within minutes.

The average particle size is usually 10 to 5000 μm, preferably
It is in the range from 100 to 4000 μm, particularly preferably from 300 to 3000 μm. Further, the geometric standard deviation indicating the particle size distribution of the polyolefin particles is usually 1.0 to 2.0, preferably
1.0 to 1.7, particularly preferably 1.0 to 1.5, more preferably
It is in the range of 1.0 to 1.3.

Also, an apparent bulk density due to gravity of the crystalline polyolefin polymer particles, usually 0.20 g / cm ³ or more, preferably 0.30~0.70g / cm ^3, particularly preferably 0.35~0.60g / cm ³
Within the range.

In the polyolefin particles produced by employing the above method, the transition metal content is usually 100 ppm or less, preferably 10 ppm or less, particularly preferably 5 ppm or less, the halogen content is usually 300 ppm or less, preferably The content is 100 ppm or less, particularly preferably 50 ppm or less.

In the production method of the present invention, the above polyolefin particles are oxidized in the gas phase and used.

This gas phase oxidation treatment is carried out by adding an organic peroxide to the above-mentioned polyolefin particles, mixing them sufficiently, and then heating the mixture to a temperature higher than the decomposition temperature of the organic peroxide in the presence of oxygen. In the present invention, such a heat treatment is performed in a gas phase.

Examples of organic peroxides used herein include dichlorobenzoyl peroxide, dicumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-bis (tert-butylperoxy) hexane, 2 , 5-Dimethyl-2,5-bis (tert-butylperoxy) hexyne-
3,1,3-bis (tert-butylperoxyisopropyl) benzene, 1,1-bis (tert-butylperoxy)
-3,3,5-trimethylcyclohexane, n-butyl-4,4
-Bis (tert-butylperoxy) bararate, dibenzoyl peroxide, tert-butylperoxybenzoate, tert-butylperoxy-2-ethylhexanoate, cyclohexanone peroxide, 2,5-dimethyl-2,5-dibenzoylperoxide Oxyhexane, tert-butyl peroxybenzoate, di-tert-butyl-diperoxyphthalate, methyl ethyl ketone peroxide and the like are included.

Such an organic peroxide is usually 0.001 to 10 parts by weight based on 100 parts by weight of the polyolefin particles to be oxidized.
It is used in a proportion by weight, preferably 0.01 to 5 parts by weight.

Such an organic peroxide can be used as it is mixed with the polyolefin particles, but can also be used by dissolving the organic peroxide in a small amount of an organic solvent. As the organic solvent used here, any organic solvent that can dissolve the organic peroxide can be used without particular limitation. Examples of such organic solvents include aromatic hydrocarbon solvents such as benzene, triene and xylene, aliphatic hydrocarbon solvents such as pentane, hexane, heptane, octane, nonane, and decane; cyclohexane, methylcyclohexane, decahydronaphthalene, and the like. Alicyclic hydrocarbon solvents, chlorobenzene, dichlorobenzene, trichlorobenzene, methylene chloride, chloroform, carbon tetrachloride, chlorinated hydrocarbons such as tetrachloroethylene, methanol, ethanol, n-propynol, is
o-propanol, n-butanol, sec-butanol,
alcohol solvents such as tert-butanol; ketone solvents such as fusetone, methyl ethyl ketone and methyl isobutyl ketone; ester solvents such as acetic acid, ethyl and dimethyl phthalate; dimethyl ether, diethyl ether and di-
Ether solvents such as n-amyl ether, tetrahydrofuran and dioxyanisole can be mentioned, and toluene, xylene and acetone are preferably used. These solvents can be used alone or as a mixture.

In the present invention, when preparing the oxidized polyolefin particles (A), it is preferable to carry out the reaction so that the polyolefin particles do not lose their particle state, and therefore, the organic solvent used for dissolving the peroxide is preferred. Is
It is used in a proportion of usually 0.1 to 30 parts by weight, preferably 1 to 20 parts by weight, based on 100 parts by weight of the polyolefin.

If organic solvents having high affinity for polyolefins such as aromatic hydrocarbons, aliphatic hydrocarbons, alicyclic hydrocarbons, and chlorinated hydrocarbons are used, these solvents penetrate into the polyolefin particles. It acts to cause some swelling of the particles and to spread the organic peroxide into the particles.

The oxidation treatment in the present invention is performed using a mixture of the polyolefin particles and the organic peroxide prepared as described above, at a temperature higher than the decomposition temperature of the organic peroxide, and preferably higher than the decomposition temperature. Heating is performed to a temperature lower than the temperature at which the particles are melted. Specifically, the heating temperature of this oxidation treatment is usually 50 to 140 ° C., preferably 6 ° C.
0-120 ° C.

In the present invention, the oxidation treatment needs to be performed in a gas phase, and is usually performed in air. Therefore, in the present invention, a dispersion medium for polyolefin particles such as an aqueous dispersion medium is not used.

Under the above temperature conditions, the time required for the vapor phase oxidation treatment is usually 0.5 to 15 hours.

Since the gas phase oxidation treatment of the polyolefin particles does not particularly need to carry out the reaction under pressure, as a reaction device, any device that can heat the mixture of the polyolefin particles and the organic peroxide to the above-described temperature may be used. In particular, the shape and the like are not particularly limited, and various heating devices can be used.
In particular, when performing a continuous gas phase oxidation treatment, a fluidized bed,
It is preferred to use a continuous heating device such as a moving bed, loop reactor, paddle dryer and the like.

As described above, the gas phase oxidation treatment of polyolefin particles not only has an advantage that the oxidation treatment of polyolefin particles can be continuously performed without using a complicated device, but also has a very It can be performed uniformly. That is, by performing the oxidation treatment in the gas phase, the difference in the degree of treatment between the surface and the deep part of the polyolefin particles is reduced.

It is considered that a polar group is formed more selectively in the amorphous part than in the crystalline part by subjecting the polyolefin particles having the crystalline part and the amorphous part to the gas phase oxidation treatment as described above.

By performing the gas phase oxidation treatment as described above, ASTM D 1238 of the oxidized polyolefin particles (A) is obtained.
Melt flow rate measured at 230 ° C according to
It is in the range of 0.1 to 500 g / 10 minutes, preferably 1 to 100 g / 10 minutes.

Further, the average particle diameter, geometric standard deviation, apparent bulk density, and the like of the polyolefin particles do not substantially fluctuate by the gas phase oxidation treatment.

In the production method of the present invention, the oxidized polyolefin particles (A) prepared as described above are added to the oxidized polyolefin particles (A) under the condition that the particle state of the oxidized polyolefin particles (A) is substantially maintained. The modified polyolefin particles are obtained by reacting the ethylenically unsaturated group-containing monomer (B).

The ethylenically unsaturated group-containing monomer (B) used herein is a monomer having an ethylenically unsaturated group, that is, a monomer having an unsaturated group copolymerizable with an α-olefin such as ethylene. Typical examples include styrene monomers, unsaturated carboxylic acids or derivatives thereof, acrylonitrile, vinyl acetate and vinyl chloride.

The styrene monomer used in the present invention can be represented by the following formula [I].

In the above formula [I], R ¹ and R ² each independently represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and specifically, a methyl group, an ethyl group, a propyl group, and an isopropyl group Can be mentioned. R ³ is
Each independently represents a hydrocarbon group having 1 to 3 carbon atoms or a halogen atom, specifically, a methyl group, an ethyl group, a propyl group and an isopropyl group, and a chlorine atom,
Bromine atoms and iodine atoms can be mentioned.

 N represents an integer of 1 to 5.

The styrene monomers can be used alone or in combination.

Specific examples of such a styrene monomer include styrene, α-methylstyrene, o-methylstyrene, p-methylstyrene, m-methylstyrene, o-chlorostyrene, p-chlorostyrene, and m-chlorostyrene. And p-chloromethylstyrene. In the present invention, among the styrene monomers represented by the above formula [I], styrene and α-methylstyrene are particularly preferable.

Examples of unsaturated carboxylic acids include acrylic acid, methacrylic acid, maleic acid, fumaric acid, tetrahydrophthalic acid, itaconic acid, citraconic acid, crotonic acid, isocrotonic acid and nadic acid (endosis-bicyclo [2,
2,1] hept-5-ene-2,3-dicarboxylic acid). Further, examples of the derivative of the unsaturated carboxylic acid include unsaturated carboxylic anhydrides, unsaturated carboxylic acid halides, unsaturated carboxylic acid amides, unsaturated carboxylic acid imides and ester compounds of unsaturated carboxylic acids. . Specific examples of such derivatives include maleenyl chloride, maleimide, maleic anhydride, citraconic anhydride, monomethyl maleate, dimethyl maleate and glycidyl maleate, and methyl methacrylate.

These unsaturated carboxylic acids and derivatives thereof can be used alone or in combination.

Among the unsaturated carboxylic acids and derivatives thereof as described above, unsaturated dicarboxylic acids or acid anhydrides or unsaturated carboxylic acid esters thereof are preferable, and further, maleic acid, nadic acid or acid anhydrides thereof, and methyl methacrylate are preferred. Particularly preferred.

As such an ethylenically unsaturated group-containing monomer,
Two or more types having different classifications can be used in combination.

The ethylenically unsaturated group-containing monomer is used usually in a proportion of 1 to 100 parts by weight, preferably 5 to 80 parts by weight, based on 100 parts by weight of the oxidized polyolefin particles.

In the present invention, a polyolefin particle (A) and the above-mentioned ethylenically unsaturated group-containing monomer (B) are combined with the above-mentioned ethylenically unsaturated group-containing monomer (B) in a gas phase condition under which the above-mentioned polyolefin particle (B) subjected to the gas phase oxidation treatment can substantially maintain the particle shape. Below, it can be obtained by grafting to the oxidized polyolefin particles (B).

Here, "gas phase conditions under which the polyolefin particles can substantially maintain the particle shape" means that the heating temperature is set to a temperature lower than the melting point of the polyolefin particles and that the reaction occurs under the gas phase conditions, and This means that the reaction is performed under a gas phase condition in which the polyolefin particles are not dissolved in a solvent or the like.

In this graft polymerization reaction, for example, a predetermined amount of each of the polyolefin particles (A), the ethylenically unsaturated group-containing monomer (B), and, if necessary, a radical initiator are charged into a reaction vessel, and the melting point of the polyolefin particles is determined. Even lower temperature, preferably 50-140 ° C, more preferably 60
It is performed by mixing while heating to a temperature of ~ 120 ° C. Under the above temperature conditions, the time of the graft reaction is usually set in the range of 0.5 to 15 hours, preferably 1 to 10 hours.

Such a graft polymerization reaction is usually performed in an inert gas atmosphere such as nitrogen gas.

In the above reaction, when a radical initiator is used, examples of the radical initiator include an organic peroxide, an organic perester, and an azo compound when the above-mentioned polyolefin particles are oxidized.

Such a radical initiator may be used as the crystalline polymer particles.
It is generally used in a proportion of 0.001 to 10 parts by weight with respect to 100 parts by weight.

And the graft amount of the graft group derived from the ethylenically unsaturated group-containing monomer in the modified polyolefin particles thus prepared is usually 0.5 to 50.
% By weight, preferably in the range of 5 to 40% by weight.

When the polyolefin particle is composed of a crystal part and an amorphous part, such a graft group tends to be preferentially introduced into the amorphous part rather than the crystal part of the polyolefin particle.
In the modified polyolefin particles into which the graft group has been introduced, mechanical strength such as impact strength is improved.

The average particle size and geometric standard deviation of the polyolefin particles, apparent bulk density, and the like do not substantially change by the gas phase oxidation treatment, but the melt flow rate tends to change by the introduction of the graft group as described above. There is
The melt flow rate measured at 230 ° C. according to ASTM D 1238 is usually in the range of 0.1 to 100 g / 10 min, preferably 0.5 to 80 g / 10 min.

The modified polyolefin particles prepared as described above can be used alone or together with other resins. As other resins that can be used here, thermoplastic resins are used.Examples of such thermoplastic resins include polyethylene terephthalate, polybutylene terephthalate, polyamide, polycarbonate, polystyrene, high-impact polystyrene, ABS, AES, MBS, PMMA, styrene-maleic anhydride copolymer, polyphenylene ether, vinyl chloride and the like can be mentioned. When used with such a thermoplastic resin, a polymer alloy having extremely excellent properties can be obtained.

The modified polyolefin particles obtained by the method of the present invention may further include an inorganic filler, an organic filler, a heat stabilizer, a weather resistance stabilizer, an antistatic agent, an anti-slip agent, an anti-blocking agent, an anti-fogging agent, and a lubricant. And additives such as pigments, dyes, natural oils, synthetic oils and waxes.

For example, as the inorganic filler, a powdery filler such as talc or titanium oxide is preferably used.

The modified polyolefin particles obtained by the method of the present invention are particularly excellent in mechanical properties such as impact resistance and rigidity, have a good appearance of the molded article, and obtain a molded article having an excellent balance of various properties. be able to.

Therefore, the modified polyolefin particles, in addition to the usual use of polyolefins, for example, by blending other resins and fillers, filler-reinforced PP, ABS resin, modified polyphenylene oxide, etc. Can be preferably used for applications requiring, for example, engineering plastics, vehicle parts, home appliance housings, OA equipment housings, and the like.

Effects of the Invention In the present invention, when preparing modified polyolefin particles as described above, polyolefin particles (A) oxidized in the gas phase are used. By oxidizing the polyolefin particles in the gas phase in this way, the oxidizing treatment can be performed without using a reaction device such as an autoclave which requires extremely high pressure resistance. Moreover, in the present invention, since both the oxidation treatment step and the modification step following the oxidation treatment step are performed in the gas phase, both steps can be performed continuously.

In addition, since the reaction is performed in the gas phase, the introduction of a water-soluble monomer is relatively easy.

Furthermore, by blending the modified polyolefin particles thus obtained with another resin, a molded article having excellent mechanical properties such as impact resistance can be prepared.

Next, the present invention will be described with reference to examples. However, the present invention should not be construed as being limited by these examples.

[Evaluation Method] In the present invention, the characteristics of the polyolefin particles were measured as follows.

Initial flexural modulus (FM) According to JIS-K7203, using a 3.2 mm thick test piece at 23 ° C
Was measured.

Flexural yield stress (FS) Measured under the same conditions as FM according to JIS-K7203.

IZ impact strength Measured using a 3.2 mm thick test piece according to JIS-K7110.

Heat distortion temperature (HDT) Measured using a 6.4 mm thick test piece according to JIS-K-7207.

Rockwell hardness Measured using a 3.2 mm thick test piece according to JIS-K7202.

Appearance of Molded Product The surface appearance of an injection molded body of 12 cm × 12 cm × 0.32 cm was evaluated by visual observation in the following two stages.

：: No flow mark ×: With flow mark Example 1 Crystalline propylene homopolymer particles (MFR = 0.3 g / 10 min)
Benzoyl peroxide 0.05 parts by weight to 100 parts by weight
After a solution dissolved in parts by weight of toluene was added and mixed well, the mixture was heated for 3 hours in a gear oven set at a temperature of 90 ° C. to perform an oxidation treatment.

 The MFR after the oxidation treatment was 36 g / 10 minutes.

Next, 100 parts by weight of the above-mentioned oxidized propylene homopolymer was charged into a stainless steel autoclave provided with a spiral double ribbon blade, and the air in the system was completely replaced with nitrogen gas.

Then, while stirring the oxidized propylene homopolymer at room temperature, 53 parts by weight of styrene, maleic anhydride 13
A mixed solution consisting of parts by weight was gradually dropped. After the dropwise addition, the mixture was stirred at room temperature for 1 hour, and then the temperature in the system was raised to 100 ° C. over 1 hour. The mixture was further stirred at this temperature for 6 hours to complete the reaction, thereby completing the co-graft polymer. Particle A was obtained. As described above, the maximum temperature of the reaction system is 100 ° C., and since this temperature is lower than the melting point of the propylene homopolymer, the co-grafting reaction could be performed without impairing the morphology of the propylene homopolymer particles. .

The co-grafted polymer particles A had a styrene graft amount of 9.8% by weight and a maleic anhydride graft amount of 1.5% by weight.

In the present invention, the graft amount is obtained by dissolving the co-grafted polymer particles in xylene at 130 ° C. and throwing this solution into a large amount of methyl ethyl ketone to precipitate a polymer.
The precipitated polymer was filtered, to obtain a purified polymer by washing, then, the pressed film was prepared by using the purified polymer obtained, 1790 cm ^-1 and 1600 cm ^-1 from the measurement results of IR spectrum of the film Was measured and determined from the absorbance measured as described above based on a previously prepared calibration curve.

The co-grafted polymer particles A obtained as described above are supplied to an injection molding machine (IS-50EP manufactured by Toshiba Corp.), and are injection-molded under the conditions of a cylinder temperature of 210 ° C. and a metal temperature of 60 ° C. I got

 Table 1 shows the physical properties of the test piece.

Example 2 As raw material polyolefin, MFR = 10 g / 10 min, 23 ° C.
Reaction was carried out in the same manner as in Example 1 except that a propylene / ethylene block copolymer having an n-decane-soluble component amount of 25% by weight was used, to obtain co-grafted polymer particles B. Styrene graft amount is 10.2% by weight, maleic anhydride graft amount is
2.0% by weight.

The co-grafted particles B obtained by the above method were molded in the same manner as in Example 1, and the physical properties were measured.

 Table 1 shows the results.

Example 3 A graft polymer particle C was obtained in the same manner as in Example 1 except that the graft monomer was changed to 50 parts by weight of styrene. The styrene graft amount of the graft polymer particles C was 10% by weight.

Next, this graft copolymer C was molded under the same conditions as in Example 1, and the physical properties were measured.

 Table 1 shows the results.

Example 4 A graft copolymer particle D was obtained by performing the same reaction as in Example 2 except that the graft monomer in Example 2 was changed to 50 parts by weight of styrene. The styrene graft amount of the graft polymer particles D was 12% by weight.

Next, the graft copolymer particles D were molded under the same conditions as in Example 2, and the physical properties were measured.

 Table 1 shows the results.

Example 5 40 parts by weight of the co-graft polymer particles A obtained in Example 1 and polybutylene terephthalate (PBT, manufactured by Toray Industries, Inc.)
1401-X04) and 60 parts by weight were fed to a 44 mmφ twin screw extruder (L / D = 30) set at a temperature of 240 ° C. and kneaded to obtain a polyolefin resin composition.

Next, the obtained polyolefin resin composition was supplied to an injection molding machine (IS-50EP manufactured by Toshiba Corporation) and injection molded under the conditions of a cylinder temperature of 270 ° C. and a mold temperature of 60 ° C. to obtain a test piece.

 Table 1 shows the physical properties of the test piece.

Example 6 40 parts by weight of the co-graft polymer particles B obtained in Example 2 were mixed with polybutylene terephthalate (PBT, manufactured by Toray Industries, Inc.).
1401-X04) and 60 parts by weight were fed to a 44 mmφ twin screw extruder (L / D = 30) set at a temperature of 240 ° C. and kneaded to obtain a polyolefin resin composition.

Next, the obtained polyolefin resin composition was supplied to an injection molding machine (IS-50EP manufactured by Toshiba Corporation) and injection molded under the conditions of a cylinder temperature of 270 ° C. and a mold temperature of 60 ° C. to obtain a test piece.

 Table 1 shows the physical properties of the test piece.

Comparative Example 1 A propylene homopolymer particle (MFR 0.38 / 10) was placed in a stainless steel autoclave equipped with a spiral double ribbon blade.
Min) 100 parts by weight were charged, and the air in the system was completely replaced with nitrogen gas.

Then, while stirring the propylene homopolymer particles at room temperature, a mixed solution composed of 0.05 parts by weight of benzoyl peroxide, 53 parts by weight of styrene, and 13 parts by weight of maleic anhydride was gradually added dropwise. After the dropwise addition, the mixture was stirred at room temperature for 1 hour, and then the temperature inside the system was raised to 100 ° C. over 1 hour. The mixture was further stirred at this temperature for 6 hours to complete the reaction. Particle E was obtained.

The co-grafted polymer particles E had a styrene graft amount of 2.8% by weight and a maleic anhydride graft amount of 0.02% by weight.
Met.

The co-grafted polymer particles E obtained as described above were molded in the same manner as in Example 1, and the physical properties were measured.

 Table 1 shows the results.

Comparative Example 2 As raw material polyolefin, MFR = 10 g / 10 min, ethylene content 25 mol%, 23 ° C., n-decane soluble component amount 25 wt%
Comparative Example 1 except that the propylene / ethylene copolymer was used
Was carried out in the same manner as above to obtain co-grafted polymer particles F.

This co-grafted polymer particle F has a styrene graft amount.
3.0% by weight and the grafted amount of maleic anhydride were 0.03% by weight.

The co-graft polymer particles F obtained as described above were molded in the same manner as in Example 1, and the physical properties were measured.

 Table 1 shows the results.

Comparative Example 3 Kneading and molding were carried out in the same manner as in Example 5 except that co-graft polymer particles E were used instead of co-graft polymer particles A in Example 5.

 Table 1 shows the results.

Comparative Example 4 Kneading and molding were carried out in the same manner as in Example 5 except that co-graft polymer particles F were used instead of co-graft polymer particles A in Example 5.

 Table 1 shows the results.

Claims (2)

(57) [Claims] 1. A mixture of polyolefin particles (A) subjected to a gas phase oxidation treatment and an ethylenically unsaturated group-containing monomer (B) is mixed with an olefin particle (A) to maintain a substantially particulate state. A method for producing modified polyolefin particles, characterized by heating under activated gas phase conditions. 2. Polyolefin particles (A) that have been subjected to a gas phase oxidation treatment are added to polyolefin particles.
The method for producing modified polyolefin particles according to claim 1, wherein the particles are prepared by reacting 0.001 to 10 parts by weight of an organic peroxide with respect to 100 parts by weight in the gas phase.