JPH05311011A - Polyolefin resin composition - Google Patents

Abstract

PURPOSE:To provide a polyolefin resin compsn. which is excellent in moldability and gives a molded article excellent in impact resistance, stiffness, and surface properties. CONSTITUTION:The compsn. contains 100 pts.wt. polyolefin and 0.1-100 pts.wt. epoxidized graft copolymer of core-shell type.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyolefin resin composition which is excellent in workability and has excellent impact resistance, rigidity and surface property when formed into a molded product.

[0002]

2. Description of the Related Art Polyolefin is widely used because it is inexpensive and has excellent physical properties. But,
For example, polypropylene has the following drawbacks.

1) When formed into a molded product, it has low impact resistance at low temperatures.

2) When formed into a molded body, its rigidity is lower than that of polystyrene, polyvinyl chloride, ABS resin and the like.

3) The viscosity and the tension at the time of melting are low, and therefore, the thermoformability (hereinafter abbreviated as thermoformability) when the sheet is formed into a sheet under vacuum, and the calender forming,
Poor moldability during blow molding or foam molding.

4) When formed into a molded product, the surface property is low. Here, "surface property" means the gloss of the surface of the molded product,
Hardness and coatability on the surface.

In order to improve the impact resistance of the polyolefin molded article, a method of mechanically mixing a rubber component such as ethylene-propylene rubber with the polyolefin, or a rubber component is introduced into the polyolefin by polymerization such as block copolymerization. The method is widely and generally practiced. But,
In the above method, since it is difficult to sufficiently control the particle size of the rubber component to be dispersed, the use efficiency of the rubber component becomes low. As a result, a polyolefin molded product having sufficient impact resistance cannot be obtained. further,
Since many rubber components are required, the rigidity of the obtained polyolefin molded product is low. Furthermore, since the rubber component to be dispersed has a large particle diameter, the surface gloss of the obtained polyolefin molding is inferior.

Conventionally, the core-shell type deforming agent has been widely used for improving the impact resistance of molded articles such as polyvinyl chloride resins. This core-shell type modifier can efficiently disperse a rubber component (core part) having a preset particle diameter, so that the resulting molded article is prevented from having low rigidity, and has a high impact resistance. It is possible to improve the sex. However, the use of non-polar polyolefins has been limited due to their poor compatibility with core-shell type modifiers. A method of adding a core-shell type modifier to a polyolefin in the presence of a specific compatibilizing agent has been disclosed (JP-A-3-185037, US Pat. No. 4,997,884). It is complicated, and there are problems such as an increase in cost due to the use of a compatibilizer and a complicated system.

As a method of improving the processability of the polyolefin, there is a method of increasing the molecular weight of the polyolefin to prevent the viscosity and tension of the polyolefin from being lowered during melting and improve the processing. But,
This method cannot adopt molding methods such as extrusion molding and injection molding, which are important processing methods for polyolefins.

[0010]

DISCLOSURE OF THE INVENTION The present invention is to provide a polyolefin resin composition which is excellent in processability and is excellent in impact resistance, rigidity and surface property when formed into a molded article.

[0011]

The polyolefin resin composition of the present invention contains a polyolefin and a core-shell graft copolymer having an epoxy group, and the epoxy group is added to 100 parts by weight of the polyolefin. The core-shell graft copolymer to be contained is contained in a proportion of 0.1 to 100 parts by weight, whereby the above-mentioned object is achieved.

Next, the present invention will be described in detail.

The polyolefin resin composition of the present invention is
It contains a polyolefin and a core-shell type graft copolymer having an epoxy group.

As the above-mentioned polyolefin, polypropylene, high density, low density or linear low density polyethylene,
Poly-1-butene, polyisobutylene, a copolymer of ethylene and propylene, an ethylene-propylene-diene terpolymer having a diene component of 10% by weight or less, polymethylpentene, ethylene, or a propylene-vinyl compound ( Examples thereof include random, block or graft copolymers (vinyl compound content is 50% by weight or less) with vinyl acetate, methacrylic acid alkyl ester, acrylic acid alkyl ester or aromatic vinyl). The above-mentioned polyolefin is preferably a polyolefin containing 50% by weight or more of a propylene component.

The polyolefin preferably has at least one reactive functional group, and examples of the reactive functional group include a carboxyl group, an amide group, an amino group, a hydroxyl group, an acid anhydride group and an epoxy group. Particularly preferred are a carboxyl group, an amide group, an amino group and a hydroxyl group which are reactive with an epoxy group. The above-mentioned polyolefin is obtained by copolymerizing or graft-polymerizing the above-mentioned monomer component having a functional group in a proportion of 20% by weight or less. Examples of the monomer having a functional group include methacrylic acid, acrylic acid, methacrylamide, acrylamide, dimethylaminoethyl methacrylate, hydroxyethyl methacrylate, maleic anhydride, glycidyl methacrylate and glycidyl acrylate. The above polyolefins may be used alone or in 2
A mixture of two or more species can be used.

The core-shell type graft copolymer having an epoxy group is contained in order to improve the processability of the polyolefin and the impact resistance of the molded product. This graft copolymer is a core-shell type graft copolymer in which a rubber-like polymer is used as a core, a vinyl-based hard polymer is used as a shell, and a shell component is graft-copolymerized in the presence of the core. And has an epoxy group.

The above-mentioned core-shell type graft copolymer having an epoxy group is a graft copolymer obtained by graft-copolymerizing a rubber-like polymer having an epoxy group as a core and a monomer component composed of a vinyl compound as a shell. A graft copolymer obtained by graft-copolymerizing a polymer, a rubber-like polymer as a core, and a monomer component containing an unsaturated glycidyl compound and a vinyl compound as a shell can be mentioned.

Examples of the unsaturated glycidyl compound contained in the monomer component include unsaturated glycidyl esters, unsaturated glycidyl ethers and epoxy alkenes, and specifically, glycidyl acrylate and glycidyl methacrylate. , Allyl glycidyl ether, itaconic acid diglycidyl ester, styrenecarboxylic acid glycidyl ester, 3,4-epoxy-1-butene and the like. Among them, glycidyl acrylate or glycidyl methacrylate is preferable.

Further, a glycidyl compound represented by the following general formula (I) can be used. The compound represented by the following general formula (I) can be produced by the method described in JP-A-60-130580.

[0020]

[Chemical 2]

(In the formula, Ar represents an aromatic hydrocarbon group having at least one glycidyloxy group and having 2 to 23 carbon atoms, and R represents a hydrogen atom or a methyl group).

The above unsaturated glycidyl compounds can be used alone or in admixture of two or more.

The content of the unsaturated glycidyl compound is
It is preferably 0.01 to 50% by weight in the monomer component. The content of the unsaturated glycidyl compound is 0.0
When it is less than 1% by weight, the compatibility between the obtained epoxy group-containing core-shell type graft copolymer and the polyolefin becomes low, so that the viscosity and the tension of the obtained polyolefin resin composition at the time of melting become low, and as a result, In some cases, the processability of the polyolefin-based resin composition and the surface property of the molded product may be insufficient. Furthermore, the rigidity and impact resistance of the molded product of the polyolefin-based resin composition may be insufficient. On the other hand, when the content of the unsaturated glycidyl compound exceeds 50% by weight, other mechanical properties of the molded product of the polyolefin-based resin composition containing the obtained epoxy group-containing core-shell type graft copolymer are There is a risk of becoming insufficient.

Examples of the vinyl compound contained in the monomer component are aromatic vinyl compounds such as styrene and α-methylstyrene; alkyl methacrylate such as methyl methacrylate, ethyl methacrylate and n-butyl methacrylate. Alkyl acrylates such as ethyl acrylate and n-butyl acrylate; acrylonitrile,
Examples thereof include unsaturated nitrile compounds such as methacrylonitrile.

The content of the vinyl compound is preferably 50 to 99.99% by weight in the monomer component. When the content of the vinyl compound is less than 50% by weight, other mechanical properties of the resulting molded product of the polyolefin resin composition containing the core-shell type graft copolymer having an epoxy group may be insufficient. There is. On the other hand, when the content of the vinyl compound exceeds 99.99% by weight, the compatibility between the obtained epoxy group-containing core-shell type graft copolymer and the polyolefin becomes low, so that the obtained polyolefin resin composition The viscosity and tension at the time of melting become low, and as a result, the processability and surface properties of the polyolefin resin composition become insufficient. Furthermore, the rigidity and impact resistance of the molded product of the polyolefin-based resin composition may be insufficient.

As the vinyl compound, it is preferable to use at least one of an aromatic vinyl compound and an alkyl methacrylate, and at least one vinyl compound other than the aromatic vinyl compound and an alkyl methacrylate. As the aromatic vinyl compound, styrene or α-methylstyrene is preferable. The methacrylic acid alkyl ester is preferably a methacrylic acid ester having an alkyl group with 1 to 4 carbon atoms. Examples of the vinyl compound other than the aromatic vinyl compound and the methacrylic acid alkyl ester include the acrylic acid alkyl ester, the unsaturated nitrile compound and the like, and the reactivity of an acid anhydride group, a carboxyl group, an amide group, an amino group, a hydroxyl group and the like. Examples thereof include vinyl compounds having a functional group, and specific examples thereof include maleic anhydride, methacrylic acid, acrylic acid, methacrylamide, acrylamide, dimethylaminoethyl methacrylate, hydroxyethyl methacrylate, and hydroxyethyl acrylate.

In the above case, the content of at least one vinyl compound among the aromatic vinyl compound and the methacrylic acid alkyl ester is 50 to 99.9 in the monomer component.
The content of 9% by weight, at least one vinyl compound other than the aromatic vinyl compound and the methacrylic acid alkyl ester is preferably 0 to 40% by weight in the monomer component.

The content of the above-mentioned monomer component is preferably 5 to 60% by weight in the core-shell type graft copolymer having an epoxy group. If the content of the above-mentioned monomer component is less than 5% by weight, the obtained core-shell type graft copolymer having an epoxy group will be aggregated, which is not preferable. On the other hand, when the content of the above-mentioned monomer component exceeds 60% by weight, the viscosity and tension of the obtained polyolefin resin composition at the time of melting become low, and as a result, the processability of the polyolefin resin composition and its molding The surface of the body may be insufficient. Furthermore, the impact resistance of the molded product of the polyolefin-based resin composition may be insufficient.

The rubber-like polymer is a polymer having a glass transition temperature of 25 ° C. or lower, and examples thereof include polybutadiene rubber, styrene-butadiene rubber, acrylonitrile-butadiene rubber, and diene acrylate such as n-butyl-butadiene rubber. -Based rubber, acrylic rubber such as poly (n-butyl acrylate), 2-ethylhexyl polyacrylate,
Examples thereof include olefin rubbers such as ethylene-propylene-diene rubber and butyl rubber, and silicone rubber such as polydimethylsiloxane. Examples of the rubber polymer having an epoxy group include the above-mentioned rubber polymers having an epoxy group, and these are, for example, the unsaturated glycidyl groups described above during the synthesis of the rubber polymer. It is obtained by copolymerizing a compound. These rubber-like polymers and rubber-like polymers having an epoxy group can be used alone or in admixture of two or more.

The content of the above rubber component is preferably 40 to 95% by weight in the core-shell type graft copolymer having an epoxy group. Content of the above rubber component is 4
If it is less than 0% by weight, the viscosity and tension of the obtained polyolefin resin composition at the time of melting are low, and as a result,
The processability of the polyolefin-based resin composition and the surface property of the molded product thereof may be insufficient. Furthermore, the impact resistance of the molded product of the polyolefin-based resin composition may be insufficient. On the other hand, the content of the rubber component is 95% by weight.
If it exceeds, the resulting core-shell type graft copolymer having an epoxy group will be lumped, which is not preferable.

The graft copolymer having an epoxy group is
It can be produced by an ordinary radical polymerization, and a polymerization method such as a suspension polymerization method or an emulsion polymerization method can be adopted.
From the viewpoint that it is easy to control the particle size and particle structure of the resulting graft copolymer having an epoxy group,
It is preferable to employ an emulsion polymerization method. During the manufacturing process,
The particles may be enlarged by adding an acid, a salt, a coagulant or the like. When the particle diameter of the obtained graft copolymer having an epoxy group is 3 μm or less, the surface property of the molded article of the polyolefin resin composition containing the obtained graft copolymer having an epoxy group becomes good. Therefore, it is preferable.

In the polyolefin resin composition of the present invention,
With respect to 100 parts by weight of the polyolefin, the core-shell type graft copolymer having the epoxy group is 0.1.
To 100 parts by weight, preferably 0.5 to 70 parts by weight. When the content of the core-shell type graft copolymer having an epoxy group is less than 0.1 part by weight,
The viscosity and tension of the obtained polyolefin-based resin composition at the time of melting are lowered, and as a result, the processability of the polyolefin-based resin composition and the surface property of the molded article thereof are insufficient. Further, the impact resistance of the molded product of the polyolefin resin composition becomes insufficient. On the other hand, if the content of the core-shell type graft copolymer having an epoxy group is more than 100 parts by weight, the original properties of the obtained polyolefin resin composition molded article, that is, the heat resistance and the like are lowered.

The polyolefin resin compound of the present invention is
If necessary, an inorganic filler such as calcium carbonate or talc; a stabilizer; a lubricant or the like may be contained. further,
If necessary, it is possible to contain a core-shell type impact resistance improver or processability improver conventionally used in polyvinyl chloride resins.

As the mixing method of the core-shell type graft copolymer having an epoxy group and the polyolefin, conventionally well-known methods such as extrusion kneading and roll kneading can be adopted. Furthermore, multi-stage mixing may be adopted, such as mixing a core-shell type graft copolymer having an epoxy group and a part of the polyolefin, and then further mixing the remaining polyolefin.

In the present invention, the processability of the polyolefin-based resin composition is the thermoformability of the resin when the polyolefin-based resin composition is molded into a sheet under vacuum or pressure-molded under vacuum. , Abbreviated as thermoformability) and calender molding, blow molding, foam molding or extrusion molding.

In the present invention, impact resistance means injection molding,
The present invention relates to impact resistance of a molded product formed by all molding methods relating to a polyolefin-based resin composition such as extrusion molding, thermoforming, calender molding, blow molding, and foam molding.

In the present invention, the rigidity and surface property are the rigidity of a molded product formed by all molding methods relating to a polyolefin resin composition such as injection molding, extrusion molding, thermoforming, calender molding, blow molding and foam molding. And regarding surface properties.

[0038]

The core-shell type graft copolymer has an epoxy group. Therefore, the compatibility between the polar core-shell type graft copolymer and the nonpolar polyolefin is improved. Therefore, by including the core-shell type graft copolymer in the polyolefin, the viscosity and the tension of the obtained polyolefin resin composition at the time of melting are significantly increased, and as a result, the processability and the processability of the polyolefin resin composition are improved. The surface property of the molded body is improved. At the same time, the impact resistance and rigidity of the molded product of the polyolefin-based resin composition become excellent.

Further, by using a polyolefin having at least one reactive functional group and a core-shell type graft copolymer having an epoxy group, the phase of the polyolefin and the core-shell type graft copolymer having an epoxy group is improved. Since the solubility is further improved, the processability of the polyolefin-based resin composition and the surface properties, impact resistance and rigidity of the molded product thereof are further improved.

[0040]

EXAMPLES Next, the present invention will be described with reference to Examples and Comparative Examples.

Example 1 70 parts by weight (solid content) of polybutadiene rubber latex having a particle diameter of 2500 Å, 30 parts by weight of a monomer component consisting of 1 part by weight of glycidyl methacrylate, 15 parts by weight of methyl methacrylate and 14 parts by weight of styrene. Was subjected to graft copolymerization by ordinary emulsion polymerization. The latex of the obtained copolymer is salted out by a usual method, dehydrated,
Dried. The final conversion was 98%, and the particle size of the obtained copolymer was 2600 angstroms.

20 parts by weight of the obtained core-shell type graft copolymer powder having an epoxy group was mixed with 100 parts by weight of polypropylene (Hypol-B-200, manufactured by Mitsui Petrochemical Co., Ltd.), and this mixture was roll-kneaded at 200.degree. A test piece was obtained by press molding. For each test piece, an Izod impact resistance test was performed according to ASTM-D256, and a bending elasticity test was performed according to ASTM-D790. Further, the surface gloss of the test piece was visually evaluated in the following three grades. The results are shown in Table 2.

◯: Very glossy Δ: Glossy ×: Almost no gloss

Separately, 20 parts by weight of the above core-shell type graft copolymer powder having an epoxy group was mixed in the same manner as above, and this mixture was used in an extruder of Brabender Plasticorder made by Brabender. Then, the mixture was extrusion-kneaded under the conditions of 200 ° C. and 40 rpm and pelletized. About the obtained pellets, using a Capillograph (manufactured by Toyo Seiki), 200 ° C, die diameter 2 m
The melt tension was measured under the conditions of m × length 10 mm, extrusion speed 20 mm / min, and take-up speed 1 m / min. The results are shown in Table 2.

Comparative Example 1 Polypropylene (Hypol-B-200, manufactured by Mitsui Petrochemical Co., Ltd.) was used as a composition, and test pieces and pellets were obtained in the same manner as in Example 1. These were subjected to the same test as in Example 1. The results are shown in Table 2.

Comparative Example 2 A test piece and a pellet were obtained in the same manner as in Example 1 except that polypropylene (Hypol-J-440, manufactured by Mitsui Petrochemical Co., Ltd.) alone was used as a composition. The results are shown in Table 2.

Comparative Example 3 Test pieces and pellets were obtained in the same manner as in Example 1 except that 100 parts by weight of polypropylene (Hypol-B-200, manufactured by Mitsui Petrochemical Co., Ltd.) and 20 parts by weight of ethylene-propylene rubber crumb were used as compositions. The results of the same tests as in Example 1 are shown in Table 2.

Examples 2-9 and Comparative Examples 4-5 Test pieces and pellets were obtained in the same manner as in Example 1 except that the composition of the core-shell type graft copolymer was changed to the composition shown in Table 1. Table 2 shows the results of the same tests as those in Example 1.

[0049]

[Table 1]

[0050]

[Table 2]

From Table 2, the polyolefin-based resin compositions of Examples 1 to 9 have higher tension in melting than the polyolefin-based resin compositions of Comparative Examples 1 to 5 and the polyolefin-based resins of Examples 1 to 9 Molded articles of the composition are Comparative Examples 1-5
It can be seen that the molded product of the polyolefin resin composition of No. 1 has high impact resistance and flexural modulus, and has good surface gloss.

[0052]

As is apparent from the above description, the core-shell type graft copolymer having an epoxy group used in the present invention has a high compatibility with polyolefin, and therefore the viscosity of the polyolefin resin composition at the time of melting is high. And the tension becomes high, and as a result, the processability of the polyolefin-based resin composition and the surface property of the molded article thereof are excellent. At the same time, the impact resistance and rigidity of the molded product of the polyolefin-based resin composition also become excellent.

Claims (11)

[Claims] 1. A polyolefin-based resin composition comprising a polyolefin and a core-shell type graft copolymer having an epoxy group, wherein the core-shell having the epoxy group is 100 parts by weight of the polyolefin. A polyolefin resin composition, wherein the type graft copolymer is contained in a proportion of 0.1 to 100 parts by weight. 2. The core-shell type graft copolymer having an epoxy group contains 40 to 95% by weight of a rubbery polymer having an epoxy group and 5 to 60% by weight of a monomer component containing a vinyl compound. The polyolefin resin composition according to claim 1, wherein the polyolefin resin composition is a graft copolymer containing 10% by weight. 3. The core-shell type graft copolymer having an epoxy group comprises 40 to 95% by weight of a rubber-like polymer.
And 5 to 60% by weight of a monomer component containing 0.01 to 50% by weight of an unsaturated glycidyl compound and 50 to 99.99% by weight of a vinyl compound, which is a graft copolymer. The polyolefin resin composition described. 4. The monomer component comprises 0.01 to 50% by weight of an unsaturated glycidyl compound, 50 to 99.% of at least one selected from the group consisting of aromatic vinyl compounds and methacrylic acid alkyl esters. 99% by weight,
At least one vinyl compound other than the aromatic vinyl compound and the methacrylic acid alkyl ester is 0 to 40.
The polyolefin resin composition according to claim 3, wherein the polyolefin resin composition contains wt%. 5. The polyolefin resin composition according to claim 3, wherein the unsaturated glycidyl compound is at least one selected from the group of compounds consisting of glycidyl acrylate and glycidyl methacrylate. 6. The unsaturated glycidyl compound is a glycidyl compound represented by the following general formula (I).
Alternatively, the polyolefin resin composition as described in 4 above. [Chemical 1] (In the formula, Ar represents an aromatic hydrocarbon group having at least one glycidyloxy group and having 6 to 23 carbon atoms, and R represents a hydrogen atom or a methyl group.) 7. The aromatic vinyl compound is at least one selected from the group of compounds consisting of styrene and α-methylstyrene, and the methacrylic acid alkyl ester has an alkyl group having 1 to 4 carbon atoms. The polyolefin resin composition according to claim 4, which is at least one kind of the methacrylic acid alkyl ester. 8. The polyolefin resin composition according to claim 1, wherein the polyolefin contains at least 50% by weight of propylene. 9. The polyolefin has at least one functional group capable of reacting with an epoxy group.
The polyolefin-based resin composition described in 1. 10. A functional group capable of reacting with the epoxy group,
The polyolefin resin composition according to claim 9, which is a group selected from the group consisting of a carboxyl group, an amide group, an amino group and a hydroxy group. 11. The polyolefin resin composition according to claim 1, wherein the core-shell type graft copolymer having an epoxy group has an average particle size of 3 μm or less.