JP3005271B2 - Method for producing modified polyolefin particles - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing modified polyolefin particles. More particularly, the present invention relates to a novel method for producing particulate modified polyolefin by performing both oxidation treatment and modification of polyolefin particles in a 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, dissolving a polyolefin and an ethylenically unsaturated group-containing monomer in an organic solvent, and in this solution,
There are known a method of performing a reaction in the presence of a peroxide, a method of reacting an ethylenically unsaturated group-containing monomer with a polyolefin melted by a kneading apparatus or the like.

Modified polyolefin prepared by such a method,
Conventionally, it has been used without any problem for ordinary applications, but conventionally, the excellent properties of modified polyolefins have not always been fully utilized.

Under such a technical background, when a modified polyolefin is produced by reacting a polyolefin with a vinyl monomer, as a polyolefin, a polyolefin in a dispersion in which the polyolefin is dispersed in an aqueous solvent is formed using an organic peroxide. It has been proposed to use an oxidized polyolefin prepared by oxidation (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 a water solvent, and it is necessary to considerably increase the oxygen concentration in the water solvent 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. In addition, a so-called blocking easily occurs during the reaction, there is a problem in workability, and a modified polyolefin which is excellent in mechanical properties such as impact strength and has a good surface appearance can be efficiently produced. It is difficult to do.

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

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:
Polyolefin particles (A), organic peroxide (B),
A mixture with an ethylenically unsaturated group-containing monomer (C) is prepared, and the mixture is heated at a temperature equal to or higher than the decomposition temperature of an organic peroxide and the polyolefin particles (A) can substantially maintain the particle shape. It is characterized in that the powdery filler (D) is added before or while heating under gas phase conditions.

In the present invention, when preparing the modified polyolefin particles as described above, a mixture of the polyolefin particles (A), the organic peroxide (B), and the monomer containing an ethylenically unsaturated group (C) is prepared. The mixture is heated at a temperature not lower than the decomposition temperature of the organic peroxide and the polyolefin particles (A)
Before or while heating under inert gas phase conditions which can substantially maintain the particle shape.
Is added. As described above, by adding the powdery filler (D) under specific conditions and continuously performing the oxidation treatment and the modification of the polyolefin particles under the gas phase condition, the oxidation treatment can be performed at a very high pressure resistance such as in an autoclave. Modified polyolefin particles can be produced efficiently and with good workability without using a reactor which requires good properties.

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, the polyolefin particles (A) and the organic peroxide (B)
And a mixture of an ethylenically unsaturated group-containing monomer (C) and a powdery filler (D).

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

That is, the polyolefin particles (A) 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 can be mentioned. .

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 (A) usually contain 50 mol% or more, preferably 80 mol% or more, particularly preferably 100 mol%, of the repeating unit derived from the above-mentioned α-olefin.

Further, the polyolefin particles (A) may contain, in addition to the above-mentioned repeating unit derived from α-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.

Furthermore, in producing the above-mentioned polyolefin particles (A), a cyclic monoene can be used. Examples of such a cyclic monoene include cyclopropene, cyclobutene, cyclopentene, cyclohexene, 3-methylcyclohexene, cycloheptene, Monocycloalkenes such as cyclooctene, cyclodecene, cyclododecene, tetracyclodecene, octacyclodecene and cycloeicosene; norbornene, 5-methyl-2-norbornene, 5-
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, 8,8a-octahydro Naphthalene, 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-1,2,3,4,4
a, 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 2,3-dichloro-1,4,5,8-dimethano-1,2,
3,4,4A, 5,8,8a-tetramethyl cycloalkenes such 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 (A), styrene and substituted styrene can also be used.

The polyolefin particles (A) 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 above-mentioned polyolefin particles (A), the above-mentioned polymerization or copolymerization is carried out by employing a gas phase method, or a method in which a reaction is carried out 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-mentioned catalyst, preferably, a catalyst component containing a transition metal of Groups IVA, VA, VIA, VIIA and VIII of the Periodic Table of the Elements, for example, titanium, zirconium, hafnium, vanadium. [A] and a group I, II and III of the Periodic Table of the Elements, such as organoaluminum compounds having at least one Al-carbon bond in the molecule.
A catalyst comprising a group III organometallic compound catalyst component [B] is used.

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

Examples of the catalyst component [A] include Periodic Table IVA
Group, a catalyst containing a transition metal atom of group VA,
Among these, a catalyst component containing at least one atom selected from the group consisting of titanium, zirconium, hafnium and vanadium is particularly preferred.

Further, as another preferred catalyst component [A], a catalyst component containing a halogen atom and a magnesium atom in addition to the above-mentioned transition metal atom, a conjugated electron to a transition metal atom belonging to Group IVA or VA of Periodic Table IV. And a catalyst component containing a compound having a group coordinated thereto.

The catalyst component [A] used in the production of the polyolefin particles (A) may be present in the reaction system in a solid state during the above-mentioned polymerization reaction or copolymerization reaction,
Alternatively, it is preferable to use a catalyst prepared so that it can exist in a solid state by being supported on a carrier or the like.

Such a catalyst component [A] is disclosed in JP-A-55-13.
Nos. 5102, 55-135103, 56-67311 and Japanese Patent Application Nos. 56-18119 and 61-21109.

Examples of the organometallic compound catalyst component [B] used together with the catalyst component [A] in producing the polyolefin particles (A) include, for example, aluminoxane, an organoaluminum obtained by reacting an organoaluminum compound with water. A compound or an organoaluminum compound obtained by reacting a solution of aluminoxane 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 (A),
Pre-polymerization is carried out prior to the main polymerization using the catalyst as described above.

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

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

For example, the polyolefin particles (A) produced as described above usually have a particle form in which crystal parts and amorphous parts are distributed in a sea-island manner. Furthermore, the crystal part is made of a crystalline polyolefin, particularly a polypropylene-based resin, and the amorphous part is suitable for forming a molded article excellent in impact resistance by using polyolefin particles made of an ethylene propylene random copolymer rubber. Thus, modified polyolefin particles can be obtained.

For example, the melt flow rate of the polyolefin particles (A) prepared as described above measured at 230 ° C. in accordance with ASTM D 1238 is usually 0.1 to 100 g / min, preferably 1 to 50 g / min.
g / 10 minutes.

Further, the average particle diameter 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 (A) is usually in the range of 1.0 to 2.0, preferably 1.0 to 1.5, particularly preferably 1.0 to 1.3.

The apparent bulk density of the polyolefin particles (A) by natural fall is usually 0.20 g / cm ³ or more, preferably 0.30 g / cm ³ or more.
It is in the range of 0 to 0.70 g / cm ³ , particularly preferably 0.35 to 0.60 g / cm ³ .

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

Examples of the organic peroxide (B) in the above mixture used in the present invention 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 (t
ert-butylperoxy) -3,3,5-trimethylcyclohexane, n-butyl-4,4-bis (tert-butylperoxy) bararate, dibenzoyl peroxide, tert-butyl
Butylperoxybenzoate, tert-butylperoxy-2-ethylhexanoate, cyclohexanone peroxide, 2,5-dimethyl-2,5-dibenzoylperoxyhexane, tert-butylperoxybenzoate, di-tert-butyl- Examples thereof include diperoxyphthalate and methyl ethyl ketone peroxide.

Such an organic peroxide (B) is usually added to 100 parts by weight of the polyolefin particles (A) in the above mixture.
It is used in a proportion of 0.001 to 10 parts by weight, preferably 0.01 to 5 parts by weight.

Such an organic peroxide (B) can be used as it is by mixing it with the polyolefin particles (A), the ethylenically unsaturated group-containing monomer (C) and the powdery filler (D). The peroxide (B) may be used by dissolving it in a small amount of an organic solvent. As the organic solvent used here, any organic solvent that can dissolve the organic peroxide (B) can be used without particular limitation. Examples of such an organic solvent include aromatic hydrocarbon solvents such as benzene, toluene and xylene, aliphatic hydrocarbon solvents such as pentane, hexane, heptane, octane, nonane, and decane; cyclohexane, methylcyclohexane, and decahydronaphthalene. Alicyclic hydrocarbon solvents such as chlorobenzene, dichlorobenzene, trichlorobenzene, methylene chloride, chloroform, carbon tetrachloride, chlorinated hydrocarbons such as tetrachloroethylene, methanol, ethanol, n-propynol, iso-propanol , N-butanol, sec-butanol, alcohol solvents such as tert-butanol, ketone solvents such as fusetone, methyl ethyl ketone, methyl isobutyl ketone,
Acetic acid, ethyl, ester solvents such as dimethyl phthalate, dimethyl ether, diethyl ether, di-n-amyl ether, tetrahydrofuran, ether solvents such as dioxyanisole, and toluene,
Xylene and acetone are preferably used. These solvents can be used alone or as a mixture.

In the present invention, the above-mentioned polyolefin particles (A)
Reacts so as not to impair the particle state. Therefore, the organic solvent used for dissolving the organic peroxide (B) is usually used in a proportion of 0.1 to 30 parts by weight, preferably 1 to 20 parts by weight, based on 100 parts by weight of the polyolefin particles (A). You. Even if such a small amount of the organic solvent is used, the above-mentioned polyolefin particles (A) do not dissolve and impair the particle state. Rather, such an amount of the organic solvent is contained in the polyolefin particles (A). It penetrates and somewhat swells the particles and acts to spread the organic peroxide (B) into the particles.

The ethylenically unsaturated group-containing monomer (C) in the above mixture used in the present invention has an ethylenically unsaturated group, that is, an unsaturated group copolymerizable with an α-olefin such as ethylene. And specific examples thereof include styrene monomers, unsaturated carboxylic acids or derivatives thereof, acrylonitrile, vinyl acetate, vinyl chloride and the like.

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

In the 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 represents a hydrocarbon group having 1 to ³ carbon atoms or a halogen atom. Specific examples include a methyl group, an ethyl group, a propyl group and an isopropyl group, and a chlorine atom, a bromine atom and an iodine atom. Can be. N is 1 to 5
Represents an integer.

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 (Endocis-bicyclo [2,2,1] hept-5-ene-
2,3-dicarboxylic acid). further,
Examples of the unsaturated carboxylic acid derivatives include unsaturated carboxylic anhydrides, unsaturated carboxylic acid halides, unsaturated carboxylic acid amides, unsaturated carboxylic acid imides, and unsaturated carboxylic acid ester compounds. Specific examples of such derivatives include methyl methacrylate, methyl acrylate, maleenyl chloride, maleimide, maleic anhydride, citraconic anhydride, monomethyl maleate, dimethyl maleate and glycidyl maleate.

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

Among the above unsaturated carboxylic acids and derivatives thereof, unsaturated dicarboxylic acids or acid anhydrides or unsaturated carboxylic anhydrides thereof are preferable, and furthermore, maleic acid, Or these acid anhydrides and methyl methacrylate are particularly preferred.

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

In the mixture used in the present invention, the ethylenically unsaturated group-containing monomer (C) is usually used in an amount of 1 to 100 parts by weight, preferably 5 to 100 parts by weight, based on 100 parts by weight of the polyolefin particles (A). It is contained in a proportion of up to 80 parts by weight.

In the present invention, the powdery filler (D) contained in the above mixture has an average particle diameter of usually 0.1 to 10 μm.
m, preferably 0.5 to 5 μm, in powder form.

In particular, in the present invention, those having an average particle diameter of 1/50 or less, preferably 1/100 or less of the average particle diameter of the obtained modified polyolefin particles are used.

Specific examples of such a powdery filler (D) include:
Silica, diatomaceous earth, titanium oxide, magnesium oxide, pumice powder, pumice balloon, aluminum hydroxide, magnesium hydroxide, basic magnesium carbonate, dolomite, calcium sulfate, potassium titanate, barium sulfate, calcium sulfite, talc, clay, Inorganic fillers such as mica, asbestos, glass flakes, glass beads, calcium silicate, montmorillonite, bentonite, graphite, aluminum powder and molybdenum sulfate, and α-cellulose, silk, cotton, hemp, polyamide resin, wood powder,
Organic fillers such as poly-4-fluoroethylene are exemplified.

Among such powdery fillers, inorganic fillers are preferable, and talc, mica, and potassium whisker titanate are particularly preferable.

In the above mixture used in the present invention, the powdery filler (D) is usually used in a proportion of 1 to 50 parts by weight, preferably 5 to 30 parts by weight, based on 100 parts by weight of the polyolefin particles. Contained.

In the present invention, the polyolefin particles (A), the organic peroxide (B), the ethylenically unsaturated group-containing monomer (C), and the powder filler (D) can be mixed in any order. However, it is preferable to mix the powdery filler (D) before or while the polyolefin particles (A) are heated. That is, in the method of the present invention, when the polyolefin particles (A) are heated, the surface of the polyolefin particles (A) may exhibit viscosity,
For this reason, particles tend to be blocked in the modification step. Therefore, in the present invention, blocking of the polyolefin particles can be effectively prevented by blending the powder filler (D) before the surface of the particles develops the viscous property. Can be prepared.

In the production method of the present invention, the above polyolefin particles (A), the organic peroxide (B), the ethylenically unsaturated group-containing monomer (C), and the powder filler (D)
Is heated under an inert gas phase condition under which the polyolefin particles (A) can substantially maintain the particle shape, whereby the polyolefin particles (A) activated with the organic peroxide and the organic peroxide are heated. It is considered that the above-mentioned monomer (C) containing an ethylenically unsaturated group is grafted onto the oxide (B) to obtain modified polyolefin particles.

Here, "the inert gas phase conditions under which the polyolefin particles can substantially maintain their particle shape" means that the heating temperature is set to a temperature lower than the melting point of the polyolefin particles and the polyolefin particles react under the gas phase conditions. And that the reaction is performed under a gas phase condition in which the polyolefin particles are not dissolved in a solvent or the like. Therefore, in the present invention, a dispersion medium for polyolefin particles such as an aqueous dispersion medium is not used.

Specifically, in the method of the present invention, predetermined amounts of the polyolefin particles (A), the organic peroxide (B), the ethylenically unsaturated group-containing monomer (C), and the powdery filler (D) are reacted. After being charged into a container and sufficiently mixed, the mixture is heated to a temperature not lower than the decomposition temperature of the organic peroxide (B) and not higher than the melting temperature of the polyolefin particles (A) under an inert gas phase condition. I do.

The heating temperature is usually 50 to 140 ° C., preferably 60 to 1
20 ° C.

The heating time is usually set in the range of 0.5 to 15 hours, preferably 1 to 10 hours.

In the present invention, since the gas phase oxidation treatment of the polyolefin particles (A) is performed as described above, it is not particularly necessary to perform the reaction under pressure. Therefore, as the reaction apparatus, the above mixture containing the polyolefin particles (A), the organic peroxide (B), the monomer containing an ethylenically unsaturated group (C), and the powdery filler (D) is heated at the above-mentioned temperature. There is no particular limitation on the shape and the like of the apparatus as long as it can be heated to various temperatures, and various heating apparatuses can be used. Particularly in the case of continuous operation, it is preferable to use a continuous heating device such as a fluidized bed, a moving bed, a loop reactor, and a paddle dryer.

As described above, the method of the present invention not only has an advantage that the treatment of the polyolefin particles (A) can be continuously performed without using a complicated apparatus, but also has the advantages of oxidation and modification. Can be performed very uniformly. That is, by performing the oxidation treatment in the gas phase, the difference between the degree of the treatment on the surface of the polyolefin particles (A) and the degree of the treatment in the deep part is reduced.

By treating the polyolefin particles (A) having a crystal part and an amorphous part as described above,
It is considered that a polar group is selectively formed in an amorphous part rather than a crystalline part.

The heating is usually performed in an inert gas atmosphere such as nitrogen gas.

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

Such a graft group can be used for polyolefin particles (A).
Is composed of a crystalline part and an amorphous part, the polyolefin particles (A) tend to be preferentially introduced into the amorphous part rather than the crystalline part. In the modified polyolefin particles into which the graft group has been introduced, mechanical strength such as impact strength is improved.

The content of the powdery filler (D) in the modified polyolefin particles thus prepared is usually 0.1%.
-40% by weight, preferably 5-30% by weight,
At least a part of the powdery filler is in a state of being attached around the modified polyolefin particles.

In the present invention, since the modified polyolefin particles are produced using the above mixture containing such a powdery filler (D), it is possible to prevent the particles from being blocked during the reaction, and to improve the workability. Is improved.

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

The modified polyolefin particles prepared as described above can be used alone or together with other resins. Here, as the other resin, a thermoplastic resin is used, and as examples of such a thermoplastic resin, polyethylene terephthalate, polyester such as 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 very excellent properties can be obtained.

The modified polyolefin particles obtained by the method of the present invention may further include a heat stabilizer, a weather resistance stabilizer, an antistatic agent, an anti-slip agent, an anti-blocking agent, an anti-fogging agent, a lubricant, a pigment, a dye, Additives such as oils, synthetic oils and waxes may be included.

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

Therefore, the modified polyolefin particles obtained by the method of the present invention require, in addition to ordinary uses of polyolefin, particularly mechanical strength such as filler-reinforced PP, ABS resin, and modified polyphenylene oxide. It can be preferably used for applications, and specifically, can be suitably used as engineering plastics, vehicle parts, home appliance housings, OA equipment housings, and the like.

Effect of the Invention In the present invention, when preparing the modified polyolefin particles as described above, the polyolefin particles (A), the organic peroxide (B), and the ethylenically unsaturated group-containing monomer (C)
And heating the mixture at a temperature equal to or higher than the decomposition temperature of the organic peroxide and under an inert gas phase condition under which the polyolefin particles (A) can substantially maintain the particle shape, Alternatively, the powdery filler (D) is added while heating. As described above, the powdery filler (D) is added under specific conditions, and the oxidizing treatment and the modification of the polyolefin particles are continuously performed under the gas phase condition. It is possible to perform the reaction efficiently without using a reaction device requiring the property, and the workability is improved.

In the modified polyolefin particles thus obtained, it is considered that the groups derived from the ethylenically unsaturated group-containing monomer and the powdery filler are uniformly distributed. By blending with the above 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 properties of the modified polyolefin particles were measured as follows.

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

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 article of 12 cm × 12 cm × 0.32 cm was evaluated by visual observation in the following two stages.

 ：: No flow mark ×: With flow mark Stirring state Judged visually.

 ：: Good stirring state, almost no agglomerates.

 X: Poor stirring state, agglomerates and wall adhesion are observed.

PP A: Crystalline propylene homopolymer with MFR = 0.3 g / 10 min B: MFR = 10 g / 10 min, ethylene content 25 md%, 23 ° C., n-decane soluble component amount 25 wt% propylene / ethylene block copolymer Polymer Example 1 Crystalline propylene homopolymer particles A (MFR = 0.3 g / 10
Min) 100 parts by weight were charged into a stainless steel autoclave equipped with a helical double ribbon blade, and the air in the system was completely replaced with nitrogen gas. Thereafter, 43 parts by weight of styrene monomer and 1.0 part by weight of benzoyl peroxide were added, and the temperature in the system was reduced to 6 parts.
The temperature was raised to 0 ° C., and stirring was performed at this temperature for 1 hour. Next, 20 parts by weight of talc were added, and the temperature in the system was set to 100 ° C.,
The reaction was completed by stirring at this temperature for 6 hours to obtain graft polymer particles. The thus obtained graft polymer particles are supplied to an injection molding machine (manufactured by Toshiba Corporation, IS-50EP), and are injection-molded at a cylinder temperature of 200 ° C. and a mold temperature of 50 ° C. to obtain a test piece. Obtained. This test piece was obtained. Table 1 shows the physical properties of the test piece.

Examples 2 to 4 and Comparative Examples 1 to 2 Reactions and molding were carried out in the same manner as in Example 1 using the raw materials in the proportions shown in the table.

 The evaluation results are shown in the table.

Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) C08F 2/44 C08F 255/00-255/08

Claims (2)

(57) [Claims] 1. A mixture of a polyolefin particle (A), an organic peroxide (B) and an ethylenically unsaturated group-containing monomer (C) is prepared, and the mixture is heated to a temperature not lower than the decomposition temperature of the organic peroxide. Adding the powdered filler (D) before or while heating at a temperature and under an inert gas phase condition under which the polyolefin particles (A) can substantially maintain the particle shape. For producing modified polyolefin particles. 2. The modified polyolefin particles according to claim 1, wherein the proportion of the organic peroxide (B) is in the range of 0.001 to 10 parts by weight per 100 parts by weight of the polyolefin particles (A). Production method. .