JPH0710935A - Graft copolymer and polyolefinic resin composition containing this copolymer - Google Patents

Abstract

PURPOSE:To obtain a resin composition with good processability, high impact resistance, high rigidity and excellent surface properties. CONSTITUTION:This resin composition consist of (a) a polyolefin backbone and (b) a vinyl polymer branch which is covalently bonded to (a), and (b) is a copolymer obtained from more than 20wt.% of at least one monomer selected from among aromatic vinyl compd., acrylic acid alkyl ester with a 1-22C alkyl group and unsatd. nitrile compd. and less than 80wt.% of other copolymerizable vinyl monomers.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a graft copolymer having a polyolefin as a backbone and a vinyl polymer as a branch, which improves the melting characteristics of the polyolefin by adding a small amount to the polyolefin and provides excellent processability, and Processability, impact resistance, rigidity, containing the graft copolymer,
The present invention relates to a polyolefin resin composition having excellent surface properties and the like.

[0002]

2. Description of the Related Art Polyolefin is widely used in various fields because it is inexpensive and has excellent physical properties. However, polypropylene, for example, has the following drawbacks. That is, 1) viscosity when melted,
Low tension, which results in low sheet vacuum formability (hereinafter referred to as thermoformability), calender formability, blow moldability, foam moldability, etc. 2) Other polystyrene, polyvinyl chloride, ABS resin with high rigidity Is lower than that of the above, 3) low impact resistance at low temperature, 4) surface properties, that is, low surface gloss, hardness, paintability, etc.

In order to improve the processability of the polypropylene, mechanical mixing of polyethylene and the like is widely performed, but the effect of improving the processability is insufficient, and therefore many polyethylene components are required, As a result, the rigidity is lowered. Further, by increasing the molecular weight of the polyolefin, the viscosity and the tension at the time of melting are improved, but this is not preferable because it makes extrusion molding, which is an important processing method of the polyolefin, difficult. In addition, attempts have been made to improve processability by adding an uncrosslinked acrylic polymer to polyethylene (US Pat. No. 415).
6703) has an insufficient compatibility and is an uncrosslinked polymer, the uncrosslinked acrylic polymer is separated from polyethylene during calendering, extrusion, etc. , Attached to the die surface of the extruder (hereinafter referred to as plate out). Therefore, the actual situation is that the workability is rather reduced.

Further, a mixture of a polyolefin obtained by polymerizing a methacrylate monomer in the presence of a polyolefin in a hydrocarbon solvent, a methacrylate polymer and a polyolefin grafted with a methacrylate is added to polypropylene to obtain a processability ( Attempts have been made to improve (vacuum formability) (Japanese Patent Laid-open No. 22316/1990), but the workability improving effect of polypropylene is poor, and the problem of plate-out due to the uncrosslinked methacrylate polymer in the mixture component. Problems such as deterioration of sheet surface property remain unsolved. Furthermore, since the manufacturing method is high temperature solution polymerization, it is not preferable in terms of manufacturing cost and safety. Further, it is necessary to remove the solvent when mixing the polyolefin, which is not preferable in terms of workability and safety.

Furthermore, in an aqueous suspension, vinyl monomers were polymerized in the presence of polypropylene particles at a temperature at which polypropylene was not substantially melted and modified with polystyrene or polymethylmethacrylate. , A method for obtaining modified polypropylene polymer particles is disclosed (Japanese Patent No. 1219793). Moreover, an attempt has been made to improve the physical properties and processability of polypropylene by adding the obtained polymer particles to polypropylene (Japanese Patent No. 1241800). Both of these patents disclose that by using an aqueous suspension polymerization, it is possible to introduce an amorphous polymer homogeneously into a polypropylene matrix and to impart various functions, but among these functions, However, improvement in workability (vacuum formability), that is, improvement in drawdown of the sheet is not substantially sufficient. Further, the polymer particles are characterized in that, when added to polypropylene, fine dispersion units of the vinyl polymer form a homogeneous dispersion without agglomeration in the blend (in styrene-modified polypropylene, It is described in Japanese Patent No. 1219793 that the size of dispersed polystyrene particles specified by an electron microscope is about 0.1 to 1 μm.), Only by finely dispersing a vinyl polymer in polypropylene in a uniform manner. Then, the workability improving effect of polypropylene is substantially poor.

[0006]

DISCLOSURE OF THE INVENTION The present invention provides a graft copolymer having a polyolefin as a backbone and a vinyl polymer as a branch, which improves the processability by being mixed with a polyolefin, By mixing the graft copolymer, and further by mixing the core-shell graft copolymer and / or the inorganic filler with these, it is possible to obtain a polyolefin resin composition having excellent processability, impact resistance, rigidity and surface property. It was intended.

[0007]

That is, the first aspect of the present invention
Is composed of a polyolefin trunk (a) and a vinyl polymer branch (b) covalently bonded to the trunk, wherein the polymer branch (b) is 20% by weight or more, the aromatic vinyl compound, and the number of carbon atoms of the alkyl group. 1 to 22 at least one monomer selected from the group consisting of alkyl acrylates and unsaturated nitrile compounds and less than 80% by weight of other vinylic copolymerizable monomers. A graft copolymer characterized by being composed of

The second aspect of the present invention is polyolefin (A) 1
15. The graft copolymer (B) 0.01 to 10 according to claim 1, which comprises 100 parts by weight and a polyolefin backbone (a) and a vinyl polymer branch (b) covalently bonded to the backbone.
A polyolefin resin composition comprising 0 part by weight of the vinyl polymer branch (b) in an amount of 0.001 to 20% by weight,

The third aspect of the present invention is polyolefin (A) 1
1 to 100 parts by weight of a polyolefin backbone (a) and a vinyl polymer branch (b) covalently bonded to the backbone.
0.01 to 100 parts by weight of the graft copolymer (B) described in 14 and 40 to 95 parts by weight of the crosslinked rubbery polymer (C1) are grafted with 60 to 5 parts by weight of a monomer (C2) composed of a vinyl compound. A polyolefin-based resin comprising 0.01 to 100 parts by weight of a core-shell graft copolymer (C) obtained by copolymerization and containing the vinyl-based polymer branch (b) in an amount of 0.001 to 20% by weight. The composition

The fourth aspect of the present invention is polyolefin (A) 1
1 to 1 parts by weight consisting of 100 parts by weight of a polyolefin backbone (a) and a vinyl polymer branch (b) covalently bonded to the backbone.
4 to 0.01 to 100 parts by weight of the graft copolymer (B) and 0.1 to 1000 parts by weight of the inorganic filler (D), and the content of the vinyl polymer branch (b) is 0. 00
1 to 20% by weight of the polyolefin resin composition,

The fifth aspect of the present invention is polyolefin (A) 1
1 to 100 parts by weight of a polyolefin backbone (a) and a vinyl polymer branch (b) covalently bonded to the backbone.
0.01 to 100 parts by weight of the graft copolymer (B) described in 14, and 40 to 95 parts by weight of the crosslinked rubbery polymer (C1), 60 to 5 parts by weight of a monomer (C2) composed of a vinyl compound. A core-shell graft copolymer (C) obtained by polymerization, 0.01 to 100 parts by weight, and an inorganic filler (D), 0.1 to 1000 parts by weight, and containing the vinyl polymer branch (b). The content of each of the polyolefin resin compositions is 0.001 to 20% by weight.

In the present invention, the graft copolymer having a vinyl-based polymerization resistance as a branch (b) and a polyolefin as a trunk (a) may be produced as long as a structure capable of exerting a processability improving effect when a polyolefin is added can be obtained. There is no need to specifically limit the law. Possible production methods include, for example, in the presence of an initiator having a high hydrogen abstraction property, a method of polymerizing a vinyl monomer in a molten polyolefin to obtain a graft copolymer, and in the presence of an initiator having a high hydrogen abstraction property. A method of dissolving or swelling a polyolefin in an organic solvent and polymerizing a vinyl-based monomer in the solution to obtain a graft copolymer, a polyolefin and a vinyl-based monomer in the presence of an initiator having a high hydrogen abstraction property. Method of obtaining a graft copolymer by heating an aqueous suspension containing a vinyl monomer, introducing reactive functional groups such as epoxy group, acid anhydride group, hydroxyl group and isocyanate group into the molecule in advance. A method for grafting a vinyl-based polymer having a functional group capable of binding to the reactive functional group into the molecule onto the above-described polyolefin trunk by a polymer reaction, olefin Obtained by such copolymerization of dimer and a diene in the presence of a polyolefin obtained by introducing an unsaturated double bond in a molecule, a method such as to obtain a graft copolymer by polymerizing a vinyl monomer.

Among these methods, an aqueous suspension containing a polyolefin and a vinyl monomer is heated in the presence of an initiator having a high hydrogen abstraction property, and the vinyl monomer is polymerized to carry out graft copolymerization. The method for obtaining a coalescence is excellent in safety in that no solvent is used in the polymerization, and the reaction product obtained through the polymerization process (the graft copolymer as a component,
It contains a non-grafted polyolefin and a non-grafted vinyl polymer. ) Is easy to handle and has excellent workability. In addition, there is no need to remove the solvent when mixing polypropylene, and workability and safety are excellent. Furthermore, considering the production on a large scale compared to other methods, in terms of equipment, safety, workability,
It seems to be excellent in almost every aspect, such as cost.

A method of heating the aqueous suspension containing the polyolefin particles and the vinyl monomer in the presence of an initiator having a high hydrogen abstraction property to polymerize the vinyl monomer to obtain a graft copolymer is concretely described. As shown below. Crystalline polyolefin (a) 100 parts (parts by weight, the same applies hereinafter), vinyl monomer (a) 1 to 500 parts, radical polymerizable initiator (c)
In order to impregnate the polyolefin with an aqueous suspension containing 0.01 to 10 parts with respect to 100 parts of the vinyl-based monomer, if necessary, under the condition that the monomer is not polymerized alone. After the original heating, the aqueous suspension is further heated to a temperature higher than the temperature at which the crystalline portion of the polyolefin substantially starts melting, and the monomer is polymerized.

The crystalline polyolefin (a) is one of propylene homopolymer, ethylene homopolymer, α-olefin homopolymer, ethylene mainly consisting of propylene, α-olefin and ethylenically unsaturated monomer. It is a copolymer with the above and has crystallinity, and specifically, for example,
Isotactic polypropylene, syndiotactic polypropylene, crystalline propylene-ethylene random copolymer, crystalline propylene-ethylene block copolymer, high density, low density, and linear low density polyethylene, poly-1-butene, poly Examples include isobutylene and polymethylpentene, which may be used alone or in combination of two or more. In particular, a propylene-based polyolefin containing 75% by weight or more of propylene is preferable.

Typical examples of the vinyl-based monomer (a) include aromatic vinyl compounds, alkyl acrylates having an alkyl group having 1 to 22 carbon atoms, unsaturated nitrile compounds, etc., which may be used alone or Used in combination of two or more. Examples of the aromatic vinyl compound include styrene and α-methylstyrene, and the alkyl group has 1 carbon atom.
As the acrylic acid alkyl ester of ~ 22, ethyl acrylate, n-butyl acrylate, acrylic acid iso
-Butyl, t-butyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, and the like, as the unsaturated nitrile compound, acrylonitrile, methacrylonitrile and the like are mentioned as typical examples, and these are used alone or in combination. The above is used in combination. Further, as the copolymerizable vinyl compound, a vinyl compound having a reactive functional group such as an acid anhydride group, a carboxylic acid group, an amino group or a hydroxy group, for example, maleic anhydride, methacrylic acid, acrylic acid or methacrylic acid is used. Amide,
Acrylamide, dimethylaminoethyl methacrylate,
Examples thereof include hydroxyethyl methacrylate and hydroxyethyl acrylate, which may be used alone or in combination of two or more.

In particular, in order to obtain a graft copolymer that more effectively exhibits a processability-improving effect when a polyolefin is mixed, and considering the versatility and cost of the monomer, the vinyl-based or vinylidene monomer used is , At least 2
At least one unit amount selected from the group consisting of an aromatic vinyl compound, an alkyl acrylate having 1 to 22 carbon atoms of an alkyl group, and an unsaturated nitrile compound in an amount of 0% (% by weight, the same applies hereinafter). And less than 80% of other copolymerizable vinyl monomers, preferably at least about 20% or more of styrene and / or n-butyl acrylate and less than about 80% by weight of copolymer. More preferably, it is a mixture of other polymerizable vinyl-based monomers, and 80% or more of styrene and / or n-butyl acrylate and less than about 20% by weight of another vinyl-based monomer which is copolymerizable. More preferably it is a mixture of bodies. These vinyl-based monomers are preferably 1 to 500 parts, and more preferably 100 parts by weight of the crystalline polyolefin (a) in order to obtain a graft copolymer that more effectively exhibits a processability improving effect when the polyolefin is mixed. 5-2
00 parts, more preferably 10 to 100 parts are used.

The radical polymerizable initiator (c) preferably has a half-life of 1 hour at about 50 to about 200 ° C.,
In order to obtain a graft copolymer that more effectively exhibits a processability improving effect when a polyolefin is mixed, an oil-soluble one and a high hydrogen abstraction property are more preferable. Preferred radically polymerizable initiators are, for example, acetyl peroxide, succinic acid peroxide, t
-Butyl peroctoate, benzyl peroxide, t
-Butylperoxymaleic acid, 1-hydroxy-1-
Hydroperoxydicyclohexyl peroxide, 1,
1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, t-butylperoxycrotonate, 2,2-bis (t-butylperoxybutane),
t-butyl peroxyisopropyl carbonate, t-
Butyl peroxypivalate, lauroyl peroxide, t-butyl peroxyisobutyrate, di-t-butyl peroxide, 1,1,3,3-tetramethylbutyl peroxy-2-ethyl hexanoate, 2, 5-dimethyl-2,5-bis (2-ethylhexanoylperoxy) hexane, 2,5-dimethyl-2,5-bis (benzoylperoxy) -hexane, t-butyl peracetate, 2,5-dimethyl -Di (hydroperoxy) hexane, t-butyl hydroperoxide, t-butyl cumyl peroxide, p-menthane hydroperoxide,
Methyl ethyl ketone peroxide, di-t-butyl peroxyphthalate, t-butyl perbenzoate, dicumyl peroxide, 2,5-dimethyl-2,5 di (t-
Butyl peroxy) hexane, 2,4 pentanedione peroxide, azo-bis-isobutyronitrile, etc. are mentioned, and these are used individually or in combination of 2 or more types. These radical polymerization initiators are preferably 0.1 to 10 parts with respect to 100 parts of the vinyl-based monomer (a), in order to obtain a graft copolymer that more effectively exhibits the processability improving effect when the polyolefin is mixed. More preferably 1
Use 5 parts. Further, in order to optimize the molecular weight of the branches of the graft copolymer, a chain transfer agent such as n-dodecyl mercaptan, which is usually used, a polymerization inhibitor such as p-benzoquinone, 1-diphenyl 2 picrylhydrazyl, a polymerization inhibitor, etc. An appropriate amount of the agent can also be used.

A specific method for producing the graft copolymer by aqueous suspension polymerization is a usual aqueous suspension polymerization method except that a polyolefin is present in the system. First, crystalline polyolefin (a) (physical shape may be pellets, powders, latexes, dispersions or the like, regardless of type), vinyl monomer (a), radical polymerizable initiator (c). Is dispersed in water with a suspending agent, an emulsifying agent, and a dispersing agent as needed. Next, in order to impregnate the crystalline polyolefin (a) with the monomer in the aqueous suspension mixture, heating is carried out, if necessary, under the condition that the monomer alone is not polymerized substantially.

The conditions under which the monomer does not polymerize alone are as follows: [10 hour half-life temperature of radical-polymerizable initiator (c) -50 ° C] to [10 hour half-radical of radical-polymerizable initiator (c)]. Period temperature −10 ° C.], preferably [10-hour half-life temperature of radical-polymerizable initiator (C) −40 ° C.] to [10-hour half-life temperature of radical-polymerizable initiator (C) −10]
[° C.] temperature condition.

Further, the monomer is polymerized by heating to a temperature higher than the temperature at which the crystalline portion of the crystalline polyolefin (a) substantially starts melting. The temperature above the temperature at which the crystalline portion in the polyolefin substantially starts melting means that the crystalline polyolefin (a) has a temperature rising rate of 10 ° C./min and a nitrogen stream (40 ml / mi) measured by DSC.
In n), the temperature is raised from room temperature to complete melting, and the intermediate temperature between the melting start temperature and the melting point (the temperature corresponding to the apex of the peak in the melting curve) obtained by the measurement [(the crystalline part of the polyolefin is substantially Temperature at which melting begins) =
(Melting start temperature in DSC measurement + melting point in DSC measurement) / 2], which is preferably a melting point ± 20 ° C., more preferably a melting point ± 10 ° C. Further, under the conditions of temperature, pressure and stirring in the production process, as long as these aqueous suspension reaction mixtures are kept in a stable state to the extent that they are not excessively aggregated or fused, the amount of water used and the suspension There are no particular restrictions on the type and amount of the agent, emulsifier, and dispersant.

The reaction product obtained by the aqueous suspension polymerization method usually contains a graft copolymer, a non-grafted polyolefin, and a non-grafted vinyl polymer as components. The primary structure of the graft copolymer in these components can be estimated by fractionating and analyzing the composition in the reaction product. For example, by heating and dissolving the reaction product in a hydrocarbon solvent such as xylene, if necessary a good solvent for vinyl polymer such as methyl ethyl ketone is added, and then by cooling the solution,
The mixture of the graft copolymer and the ungrafted polyolefin and the ungrafted vinyl polymer can be separated as a precipitate and a solution in a solution, respectively. Purify the fractionated, non-grafted vinyl polymer and weigh it, or purify the mixture of the fractionated graft copolymer and the non-grafted polyolefin and perform elemental analysis, etc. This makes it possible to estimate the graft ratio and the content of vinyl polymer branches in the graft copolymer. Furthermore, the molecular weight of the branches of the graft copolymer can be estimated by purifying the fractionated non-grafted vinyl polymer and measuring the molecular weight thereof. In the present invention, (molecular weight of branch of graft copolymer) = (molecular weight of non-grafted vinyl polymer).

Usually, the molecular weight of the branch (b) of the graft copolymer obtained by the aqueous suspension polymerization method is about 1000 to 2,000,000 as the weight average molecular weight in terms of polystyrene in GPC measurement, the catalyst species and the amount. , Polymerization temperature, monomer type, concentration, chain transfer agent, combined use of polymerization inhibitor and polymerization inhibitor, etc., can be adjusted by various conditions relating to polymerization, but in the present invention, the polyolefin processability improving effect is particularly effective. The weight average molecular weight of the branches of the graft copolymer to be expressed in the above is preferably 10,000 to 200.
It is 0000. In addition, the content of the vinyl polymer branch (b) in the graft copolymer in the reaction product obtained by the aqueous suspension polymerization method is usually about 0. It is 1 to 30%. When the reaction product obtained in the aqueous suspension polymerization method is observed with an electron microscope, the domain has an average dispersed particle size of about 0.01 to 10 μm in the polyolefin, and about 0.01 for small particles, although it varies depending on the polymerization recipe. A homopolymer finely dispersed vinyl polymer can be confirmed with ~ 0.08 μm domequin, and it is presumed that this is mainly a non-grafted vinyl monomer.

The reaction product in the aqueous suspension polymerization method is
It is characterized by the fact that it contains a polyolefin grafted with a vinyl polymer, which exhibits a processability improving effect.
The reaction product in the aqueous suspension polymerization method inevitably contains a non-grafted vinyl polymer and other non-grafted polyolefin as other components. In general, it may be used as it is. That is, even if the two components are blended without being separated, the effect of improving the processability is not particularly affected. Further, of course, a mixture obtained by removing the ungrafted vinyl polymer from the reaction product in the aqueous suspension polymerization method by fractionation, that is, a mixture of a graft copolymer and a non-grafted polyolefin is purified, The effect of improving the processability is exhibited even if is added to the polyolefin serving as the matrix.

As described above, in the aqueous suspension polymerization method, under a high temperature condition where the polymerization temperature is equal to or higher than the temperature at which the crystalline portion of the polyolefin substantially starts melting, the proportion of the amorphous portion in the polyolefin increases, Simultaneously with the polymerization of the monomers, the grafting of the monomer to the polyolefin in the amorphous portion is promoted. At a temperature condition below the temperature at which the crystalline portion of the polyolefin substantially starts melting, the polymerization of the monomers proceeds, but the progress of the grafting of the monomer to the polyolefin becomes insufficient, and the vinyl-based polyolefin is present in the polyolefin. Although it is possible to finely disperse the polymer, it is difficult to obtain a graft copolymer that exhibits a processability improving effect.

The graft copolymer (B) obtained as described above is mixed with the polyolefin (A), the core-shell graft copolymer (C) and / or the inorganic filler (D) to obtain a processability, Provided is a polyolefin resin composition having excellent impact resistance, rigidity and surface property. In the present invention, the polyolefin (A) to which the graft copolymer is added is polypropylene, high density, low density and linear low density polyethylene, poly-1-butene, polyisobutylene, propylene and ethylene, And / or a random or block copolymer in any ratio with 1-butene, an ethylene-propylene-diene terpolymer having a diene component of 10% or less in any ratio of ethylene and propylene, polymethylpentene, Random, block, and graft copolymers of ethylene or propylene with vinyl compounds such as 50% or less of vinyl acetate, methacrylic acid alkyl ester, acrylic acid alkyl ester, and aromatic vinyl are included, and these are used alone or in combination. The above is used in combination. In particular, a propylene-based polyolefin containing 50% or more of propylene, or a propylene-based polyolefin 100 containing 50% or more of propylene.
Part and a mixture of 0.1 to 100 parts of an ethylene-based polyolefin containing 50% or more of ethylene, and further AST
Melt flow index according to MD 1238 is 10
The following, more preferably 5 or less, and even more preferably 2.5 or less have high melt tension and excellent processability, and kneading and dispersibility of graft copolymer, inorganic filler, etc. It is good and suitable for manifesting the effects of the present invention. The melt flow index is ASTM D1238.
In the case of propylene-based polyolefin,
2.16 kg load, 1 for ethylene-based polyolefin
It is measured at 90 ° C. and a load of 2.16 kg.

As the core-shell graft copolymer (C) in the present invention, a crosslinked rubbery polymer having a glass transition temperature of 25 ° C. or lower is polymerized in the core layer alone to give a glass transition temperature of 25 ° C. or higher. A core-shell type graft copolymer having a hard layer made of a vinyl compound in the shell layer is preferable. The core-shell graft copolymer referred to in the present invention is a concept including a product obtained by graft-copolymerizing a shell component in the presence of a crosslinked rubber-like polymer forming a core layer.

The core-shell graft copolymer (C) is
It is obtained by graft-copolymerizing a monomer component (C2) composed of a copolymerizable vinyl compound with the crosslinked rubber-like polymer (C1). The crosslinked rubber-like polymer (C1) is a polymer having a glass transition temperature of 25 ° C. or lower, and is a diene compound composed of 60 to 100% of a diene compound and 40 to 0% of another vinyl compound copolymerizable therewith. Rubber, acrylic rubber having 60 to 100% of acrylic acid alkyl ester having 2 to 22 carbon atoms in the alkyl group, and 40 to 0% of other vinyl compound copolymerizable therewith, and other olefin rubber, silicone Typical examples are crosslinked rubbery polymers such as rubber, which may be used alone or in combination of two or more kinds. As the diene compound used in the diene rubber, butadiene, isoprene, chloroprene and the like are used, and as the vinyl compound copolymerizable therewith, an aromatic vinyl compound and an alkyl group having 1 carbon atom are used.
Representative examples thereof include methacrylic acid alkyl ester having .about.22, acrylic acid alkyl ester having an alkyl group having 1 to 22 carbon atoms, and unsaturated nitrile compound, and these are used alone or in combination of two or more kinds.

As the aromatic vinyl compound, styrene,
α-methylstyrene and the like have an alkyl group having 1 to 2 carbon atoms.
Examples of the methacrylic acid alkyl ester of 2 include methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, iso-butyl methacrylate, and t-methacrylic acid.
Butyl, 2-ethylhexyl methacrylate, stearyl methacrylate, and the like, examples of the alkyl acrylate having an alkyl group having 1 to 22 carbon atoms include ethyl acrylate, n-butyl acrylate, iso-butyl acrylate, and t-acrylate. -Butyl, 2-ethylhexyl acrylate, stearyl acrylate, etc., and acrylonitrile, methacrylonitrile, etc. are mentioned as typical examples of unsaturated nitrile compounds, and these are used alone or in combination of two or more. As the copolymerizable vinyl compound, an acid anhydride group, a carboxylic acid group, an amino group, a vinyl compound having a reactive functional group such as a hydroxy group, for example, maleic anhydride, methacrylic acid, acrylic acid, methacrylamide, Examples thereof include acrylamide, dimethylaminoethyl methacrylate, hydroxyethyl methacrylate, and hydroxyethyl acrylate, which may be used alone or in combination of two or more.

Examples of the alkyl acrylate having an alkyl group having 2 to 22 carbon atoms, which is used for the acrylic rubber, include ethyl acrylate, n-butyl acrylate,
Iso-butyl acrylate, t-butyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, and the like, and other vinyl compounds copolymerizable therewith include aromatic vinyl compounds and alkyl groups having 1 to 10 carbon atoms. Representative examples thereof include alkyl methacrylates of No. 22 and unsaturated nitrile compounds, which are used alone or in combination of two or more kinds. Examples of the aromatic vinyl compound include styrene and α-methylstyrene, and examples of the alkyl methacrylate having an alkyl group having 1 to 22 carbon atoms include methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, and isomethacrylate. -Butyl, t-butyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, and the like, examples of the unsaturated nitrile compound include acrylonitrile, methacrylonitrile, and the like, and these are alone or in combination of two or more. Used in combination.

As the copolymerizable vinyl compound, a vinyl compound having a reactive functional group such as an acid anhydride group, a carboxylic acid group, an amino group or a hydroxy group, for example, maleic anhydride, methacrylic acid, acrylic acid, Methacrylamide, acrylamide, dimethylaminoethyl methacrylate, hydroxyethyl methacrylate, hydroxyethyl acrylate and the like can be mentioned, and these can be used alone or in combination of two or more.

Representative examples of the olefin rubber include ethylene-propylene-diene rubber and butyl rubber, and examples of the silicone rubber include crosslinked rubber-like polymers such as polydimethylsiloxane.
Used in combination of two or more species. Particularly, a diene rubber or an acrylic rubber having a content of 50% or more is preferable from the viewpoint of compatibility with polyolefin. In addition,
An acrylic rubber content of 50% or more is preferable from the viewpoint of thermal stability.

As the cross-linking method, a method usually used in this field can be used. For example, self-crosslinking with butadiene, crosslinking with the use of polyfunctional crosslinking agents such as divinylbenzene and 1,3-butadiol dimethacrylate, crosslinking with the use of grafting agents such as allyl methacrylate, allyl acrylate and diallyl phthalate, peroxidation. These can be used in combination of two or more kinds such as physical crosslinking. The crosslinked rubbery polymer is prepared so that the crosslinked gel content is preferably 50% or more, more preferably 60% or more. When it is less than 50%, for example, in calendering, the resin plate-outs on the roll surface, and the workability improving effect is not sufficient, which is not preferable.
The crosslinked gel component is measured as an insoluble component separated by an ultracentrifuge after being immersed in a good solvent for the rubber component, such as toluene and methyl ethyl ketone, for 48 hours.

The copolymerizable vinyl compound (C2) used in the graft polymerization is an aromatic vinyl compound, a methacrylic acid alkyl ester having an alkyl group having 1 to 22 carbon atoms, or an alkyl group having 1 to 22 carbon atoms. Representative examples thereof include acrylic acid alkyl esters, unsaturated nitrile compounds, and the like, and these may be used alone or in combination of two or more kinds. Specific examples thereof include those described for the crosslinked rubbery polymer (C1).

The core-shell graft copolymer (C) is
Crosslinked rubber-like polymer having a glass transition temperature of 25 ° C or lower (C
1) It is obtained by graft-copolymerizing 40 to 95 parts with 60 to 5 parts of a monomer component (C2) consisting of a copolymerizable vinyl compound having a glass transition temperature of 25 ° C. or higher when polymerized by itself. .

Further, preferably, a crosslinked rubbery polymer (C
1) 40 to 95 parts of a monomer component (C2) consisting of 100 to 50% of aromatic vinyl and / or alkyl methacrylate and 0 to 50% of another copolymerizable vinyl compound is graft-copolymerized. can get. Crosslinked rubbery polymer (C
If 1) is less than 40 parts, the effect of improving the workability and impact resistance is lowered, and if it exceeds 95 parts, the graft copolymer is agglomerated, which is not preferable. As aromatic vinyl, styrene and α-methylstyrene are preferable, and as methacrylic acid alkyl ester, methacrylic acid alkyl ester having 1 to 4 carbon atoms is preferable, and these are used alone or in combination of two or more kinds. If the glass transition temperature of the cross-linked polymer is less than 25 ° C, the workability and impact resistance improving effect are lowered, which is not preferable. Further, if the glass transition temperature of the product obtained by polymerizing only the monomer component to be graft-copolymerized is less than 25 ° C., the graft copolymer is agglomerated, which is not preferable.

Regarding the glass transition temperature and its measurement here, for example, Polymer Handbook Second Edition (197).
5). Further, in the present invention, the glass transition temperature of the copolymer is a value calculated by the following formula. 1 / Tg = Wa / Tga + Wb / Tgb Tg: glass transition temperature of copolymer composed of components a and b Tga: glass transition temperature of component a alone Tgb: glass transition temperature of component b alone Wa: weight fraction of component a Wb: Weight fraction of component b

The core-shell graft copolymer (C) is
Polymerization can be carried out by ordinary radical polymerization, and a polymerization method such as suspension polymerization or emulsion polymerization is used. From the viewpoint of controlling the particle system, particle structure, etc., emulsion polymerization is preferred. Also, acid, salt,
The particles can be enlarged by adding a coagulant or the like.
The particle size is preferably 3 μm or less from the viewpoint of surface property.

Typical examples of the inorganic filler (D) used in the present invention include heavy calcium carbonate, light calcium carbonate, talc, glass fiber and the like, and these are used alone or in combination of two or more kinds. . Particularly, heavy calcium carbonate, light calcium carbonate, talc and the like are preferable.

The graft copolymer (B) is 0.01 to 100 parts with respect to 100 parts of the polyolefin (A), and the vinyl polymer branch (b) of the graft copolymer is 0.001 to 2 parts.
It is mixed so as to contain 0%. If the amount is less than 0.01 part, the effect of the present invention is not sufficiently exhibited, and 10
If it exceeds 0 parts, the inherent properties such as heat resistance and rigidity of polyolefin are impaired. Further, the vinyl-based polymer branch (b) has a density of 0.
If it is less than 001%, the workability improving effect is not sufficient, and
If it exceeds 20%, versatility such as low cost is impaired.

The core-shell graft copolymer (C) was used in an amount of 0.0 to 100 parts of the polyolefin (A).
1 to 100 parts are mixed. If it is less than 0.01 part, the surface property is
The workability and impact resistance improvement effects are not sufficient, and 10
If it exceeds 0 parts, the inherent properties such as heat resistance and rigidity of polyolefin are impaired.

The inorganic filler (D) is mixed in an amount of 0.1 to 1000 parts with respect to 100 parts of the polyolefin (A). If it is less than 0.1 part, the effect of improving the rigidity is not sufficient, and if it exceeds 1000 parts, the surface property is deteriorated.

If desired, stabilizers, lubricants and the like may be added to the polyolefin resin composition of the present invention. As the stabilizer, pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], triethylene glycol-bis [3- (3-t-butyl-5-methyl) -4-
Hydroxyphenyl) propionate] and other phenolic stabilizers, tris (monononylphenyl) phosphite, tris (2,4-di-t-butylphenyl) phosphite and other phosphorus stabilizers, dilaurylthiodipropionate, etc. Examples of the sulfur-based stabilizers and lubricants include lauric acid, palmitic acid, oleic acid, stearic acid, sodium salts, calcium salts, magnesium salts, etc., each as a representative example, and these may be used alone or in combination of two or more. Used in combination. Further, if necessary, a core-shell type processability improver having an uncrosslinked hard core layer, which has been conventionally used for polyvinyl chloride resins, can be used.

The method of mixing the graft copolymer (B), the core-shell graft copolymer (C), the inorganic filler (D) and the polyolefin (A) may be extrusion kneading, roll kneading, etc.
Conventional methods well known can be used. The polyolefin-based resin composition obtained by the present invention has greatly improved processability, and impact resistance, rigidity, surface property, etc., including a processing method that cannot be processed by conventional polyolefin-based resin compounds. A molded product can be produced by various processing methods, and a useful molded product can be obtained. Typical examples of the processing method of the polyolefin resin compound improved in the present invention include calendar processing, extrusion processing, thermoforming processing, blow molding processing, injection molding processing, and foam molding processing.
Further, useful molded articles obtained in the present invention include sheet-shaped molded articles, film-shaped molded articles, thermoformed articles, hollow molded articles,
Representative examples include injection molded products and foamed molded products.

[0045]

The present invention will be described in more detail based on the following examples, but the invention is not intended to be limited thereto. In the following description, “%” and “part” represent “% by weight” and “part by weight” respectively, unless otherwise specified.

Example 1 [Production of Polymer Mixture A Containing Styrene-Grafted Polypropylene] Random polypropylene particles (ethylene content 3
%, DSC melting start temperature 80 ° C., melting point 146.7 ° C.) 7
00 parts, styrene 300 parts, calcium phosphate 100 parts,
6 parts of an emulsifier and 3.6 parts of di-t-butyl peroxide were mixed and mixed with stirring, and the aqueous suspension was heated and stirred at 100 ° C. for 1 hour, and then further heated and stirred at 140 ° C. for 5 hours to carry out polymerization. It was completed. The obtained particles were washed with water to remove residual monomer, catalyst, calcium phosphate and emulsifier, and then dried to obtain a polymer mixture A containing styrene-grafted polypropylene. The polymer mixture A was white and granular, and its conversion rate was 90%. A small amount of the obtained polymer mixture A was weighed, dissolved in hot xylene, further added with methyl ethyl ketone and cooled, and the precipitate was filtered and dried under reduced pressure to obtain a mixture of styrene-grafted polypropylene and ungrafted polypropylene. Obtained. The mixture was weighed, and the styrene branch% was determined from the mass balance to be about 5%.

Example 2 [Production of Polymer Mixture B Containing n-Butyl Acrylate Grafted Polypropylene] Produced in the same manner as in Example 1 except that n-butyl acrylate was used as a monomer instead of styrene, and an acrylic resin was prepared. A polymer mixture B containing n-butyl grafted acid polypropylene was obtained.
The polymer mixture B was white and had a conversion rate of 95.
%Met. Further, the n-butyl acrylate branch% calculated was about 5%.

Example 3 [Production of Polymer Mixture C Containing n-Butyl Acrylate and Methyl Methacrylate Grafted Polypropylene] Instead of styrene as a monomer, n-butyl acrylate / methyl methacrylate = 3/7 (weight ratio) Manufactured in the same manner as in Example 1 except that the monomer mixture of
A polymer mixture C containing n-butyl acrylate and methyl methacrylate graft polypropylene was obtained. The polymer mixture C was white granular, and the conversion rate was 94%. The ratio of n-butyl acrylate: methyl methacrylate branch was about 3%.

Example 4 [Production of Polymer Mixture D Containing Styrene and Methyl Methacrylate Grafted Polypropylene] Styrene / methyl methacrylate = 3 instead of styrene as a monomer
A polymer mixture D containing styrene and methyl methacrylate graft polypropylene was obtained by the same method as in Example 1 except that a monomer mixture of / 7 (weight ratio) was used. The polymer mixture D was white granular, and the conversion rate was 94%. Further, the styrene content and the methyl methacrylate branch content were determined to be about 3%.

Example 5 [Production of Polymer Mixture E Containing n-Butyl Acrylate and Styrene Grafted Polypropylene] Instead of styrene, a monomer mixture of n-butyl acrylate / styrene = 7/3 (weight ratio) was used as a monomer. A polymer mixture E containing n-butyl acrylate and styrene-grafted polypropylene was produced by the same method as in Example 1 except that the polymer mixture was used. The polymer mixture E was white granular, and its conversion rate was 96%. In addition, acrylic acid n
The butyl and styrene branch percentages were determined to be about 5%.

Example 6 [Preparation of polymer mixture A'without styrene polymer not grafted from polymer mixture A] The polymer mixture A obtained in Example 1 was dissolved in hot xylene, and methyl ethyl ketone was further added. After cooling, the precipitated precipitate was filtered and dried under reduced pressure to obtain a mixture of styrene-grafted polypropylene and ungrafted polypropylene from which the ungrafted styrene polymer was removed.

Example 7 A mixture of 1 part by weight of the polymer mixture A, 100 parts by weight of a powder of Homopoly polypropylene manufactured by Mitsui Petrochemical and Hypol-B-200 was mixed in a twin screw extruder having a screw diameter of 44 mm and an L / D of 30 at 200 ° C. Extrusion kneading at 100 rpm,
Pelletized. The mixing ratio is shown in Table 1. Various test pieces were obtained by roll kneading and press molding the obtained pellets at 200 ° C. The appearance of roll sheets during roll kneading was visually compared. ASTM-D 256, AST
According to MD-790, Izod impact resistance test,
A bending elasticity test was conducted. Also, in the same manner, 100 mm
A sheet is formed into a corner and a thickness of 1.5 mm, and the opening is 76 mm.
Fix with a corner clamp and measure the drawdown of the sheet in a 190 ° C oven for 30 minutes. Also, the obtained pellets were subjected to Toyo Seiki Capillograph at 200 ° C., die diameter 1 mm × length 1 mm, extrusion speed 5 mm /
Min, the melt tension at a take-up speed of 1 m / min was measured. The obtained results are shown in Table 2.

Examples 8 to 16 and Comparative Examples 1 to 3 Tests were conducted in the same manner as in Example 7 except that the mixing ratio was changed as shown in Table 1. The results are shown in Table 2.

[0054]

[Table 1]

[0055]

[Table 2]

From the results shown in Table 2, it can be seen that the resin composition obtained by mixing the polymer mixtures A to E with polypropylene has remarkably improved the drawdown which is an index of thermoforming and blow molding. Further, the drawdown of the resin composition obtained by mixing the polymer mixture A ′ with polypropylene is equivalent to that of the polymer composition A mixed with polypropylene, so that the graft copolymer in the polymer mixture is effective in improving the drawdown. You can see that there is.

Reference Example 1 [Production of Core-Shell Graft Copolymer F] Polymerization was carried out by ordinary emulsion polymerization to obtain a crosslinked polybutadiene rubber. No cross-linking agent was used. The particle size was 2500 Å, and the crosslinked gel content was 85%. In the presence of 70 parts (solid content) of the obtained polybutadiene rubber latex,
30 parts of a monomer component consisting of 15 parts of methyl methacrylate and 15 parts of styrene was graft-copolymerized by ordinary emulsion polymerization. The final conversion was 98% and the particle size was 2600 angstroms. The obtained polymer latex was salted out by a usual method, dehydrated and dried to obtain a core-shell graft copolymer F.

Examples 17 to 20, Comparative Examples 4 and 5 Polypropylene, Polymer mixture A containing styrene-grafted polypropylene obtained in Example 1, n-butyl acrylate obtained in Example 5, styrene grafted Polymer mixture E containing polypropylene, the core-shell graft copolymer obtained in Reference Example 1 above is shown in Table 3.
A test was conducted in the same manner as in Example 7 except that the ingredients were compounded as shown in FIG. The results are shown in Table 4.

[0059]

[Table 3] Abbreviation) PP: Mitsui Petrochemical, polypropylene, high pole-
B-2000, the melt flow rate at 230 degreeC is 0.
5

[0060]

[Table 4]

From the results shown in Table 4, the resin composition obtained by mixing the polymer mixture A or E and the core-shell graft copolymer F with polypropylene was remarkably improved in drawdown which is an index of thermoforming, blow molding and the like. At the same time, it can be seen that the surface property of the roll sheet is improved and the impact resistance is also improved.

Examples 21-24, Comparative Examples 6-9 Polypropylene, polyethylene, obtained in Example 1,
Polymer blend A containing styrene-grafted polypropylene, core-shell graft copolymer F obtained in Reference Example 1, light calcium carbonate surface-treated with fatty acid and having a particle size of 0.15 μm were added as shown in Table 5. Was tested in the same manner as in Example 7. The results are shown in Table 6.

[0063]

[Table 5] Abbreviation) PP: Mitsui Petrochemical, polypropylene, high pole-
B-2000, the melt flow rate at 230 degreeC is 0.
5 LDPE: Melt flow rate at 190 ° C is 0.25
RODENSITY POLYETHYLENE CALCIUM CARBONATE: FABRIC ACID-FACED PARTICLE SYSTEM 0.15
μm light calcium carbonate

[0064]

[Table 6]

From the results shown in Table 6, the resin composition obtained by mixing the polymer mixture A, the core-shell graft copolymer F, and / or the inorganic filler D with polypropylene was used as an index for thermoforming, blow molding and the like. It can be seen that the roll sheet surface property is improved at the same time that the down is remarkably improved, and that the balance between impact resistance and rigidity is excellent.

[0066]

INDUSTRIAL APPLICABILITY As described above, the graft copolymer of the present invention is mixed with the core-shell graft copolymer and / or the inorganic filler, if necessary, in the polyolefin to improve the processability and impact resistance. A polyolefin resin composition having good rigidity and surface property is provided.

Continued Front Page (72) Inventor Taizo Aoyama 4-13-10 Nishihata, Takasago City, Hyogo Prefecture

Claims (18)

[Claims] 1. An aromatic vinyl compound or an alkyl group comprising a polyolefin backbone (a) and a vinyl polymer branch (b) covalently bonded to the backbone, wherein the polymer branch (b) is 20% by weight or more. From at least one monomer selected from the group consisting of C1-C22 alkyl acrylates and unsaturated nitrile compounds, and less than 80% by weight of other copolymerizable vinyl-based monomers. A graft copolymer comprising the above polymer. 2. Styrene and / or n-butyl acrylate containing 20% by weight or more of vinyl polymer branch (b),
The graft copolymer according to claim 1, which comprises a polymer obtained from less than 0% by weight of another copolymerizable vinyl monomer. 3. The graft copolymer according to claim 1, wherein the vinyl polymer branch (b) is a polymer obtained from 20% by weight or more of styrene and less than 80% by weight of methyl methacrylate. 4. The graft copolymer according to claim 1, wherein the vinyl-based polymer branch (b) comprises a polymer obtained from 20% by weight or more of n-butyl acrylate and less than 80% by weight of methyl methacrylate. Coalescing. 5. A styrene and / or n-butyl acrylate containing 80% by weight or more of a vinyl polymer branch (b),
The graft copolymer according to claim 1, which is composed of a polymer obtained from a copolymerizable vinyl monomer of less than wt%. 6. The graft copolymer according to claim 1, wherein the vinyl polymer branch (b) is a polymer obtained from 80% by weight or more of styrene and less than 20% by weight of methyl methacrylate. 7. The graft copolymer according to claim 1, wherein the vinyl polymer branch (b) is a styrene homopolymer. 8. The vinyl-based polymer branch (b) is acrylic acid n.
-The graft copolymer according to claim 1, which comprises a butyl homopolymer. 9. The graft copolymer according to claim 1, wherein the polyolefin backbone (a) is a propylene-based polyolefin obtained by polymerizing a monomer containing 75% by weight or more of propylene. 10. The polyolefin trunk (a) has a weight average molecular weight of about 30,000 to 2,000,000.
9. The graft copolymer according to 9. 11. A polyolefin trunk (a) having a weight average molecular weight of about 100,000 to 500,000.
10. The graft copolymer according to 10. 12. The vinyl polymer branch (b) has a weight average molecular weight of about 1,000 to 2,000,000.
1. The graft copolymer according to 1. 13. The vinyl-based polymer branch (b) has a weight average molecular weight of about 10,000 to 2,000,000.
12. The graft copolymer according to item 12. 14. The weight average molecular weight of the vinyl polymer branch (b) is about 200,000 to 2,000,000.
~ 13 graft copolymer. 15. A polyolefin (A) 100 parts by weight,
And 0.01 to 100 parts by weight of the graft copolymer (B) according to claims 1 to 14, which is composed of a polyolefin trunk (a) and a vinyl polymer branch (b) covalently bonded to the trunk. Content of vinyl polymer branch (b) is 0.00
The polyolefin resin composition is 1 to 20% by weight. 16. 100 parts by weight of polyolefin (A),
15. The graft copolymer (B) 0.01 to 100 parts by weight, which is composed of a polyolefin trunk (a) and a vinyl polymer branch (b) covalently bonded to the trunk, and a crosslinked rubber-like material. Core-shell graft copolymer (C) obtained by graft-copolymerizing 40 to 95 parts by weight of the polymer (C1) with 60 to 5 parts by weight of a monomer (C2) composed of a vinyl compound.
A polyolefin resin composition, which comprises 0.01 to 100 parts by weight, and the content of the vinyl polymer branch (b) is 0.001 to 20% by weight. 17. A polyolefin (A) 100 parts by weight,
0.01 to 100 parts by weight of the graft copolymer (B) according to claims 1 to 14, which comprises a polyolefin backbone (a) and a vinyl polymer branch (b) covalently bonded to the backbone, and an inorganic filler ( D) A polyolefin resin composition comprising 0.1 to 1000 parts by weight, and the content of the vinyl polymer branch (b) is 0.001 to 20% by weight. 18. A polyolefin (A) 100 parts by weight,
The graft copolymer (B) according to claim 1, which comprises a polyolefin backbone (a) and a vinyl polymer branch (b) covalently bonded to the backbone, in an amount of 0.01 to 100 parts by weight, and a crosslinked rubber-like polymer. Core-shell graft copolymer (C) obtained by graft-copolymerizing 60 to 5 parts by weight of a monomer (C2) composed of a vinyl compound with 40 to 95 parts by weight of the polymer (C1).
01 to 100 parts by weight, and inorganic filler (D) 0.1 to 1
A polyolefin resin composition consisting of 000 parts by weight and having a vinyl polymer branch (b) content of 0.001 to 20% by weight.