JP2877348B2 - Thermoplastic resin composition - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a thermoplastic resin composition having excellent rigidity, impact strength, heat resistance, paintability and chemical resistance, as well as good moldability. More specifically, a composition comprising a modified polyolefin of a thermoplastic resin modified with at least one functional group selected from the group consisting of an amino group, a hydroxyl group, and an ester group and a maleimide-based copolymer, The present invention relates to a thermoplastic resin composition having improved rigidity, coating properties, heat resistance and molding processability, and further improved impact strength and chemical resistance of a maleimide copolymer.

[Conventional technology]

Polyolefin is excellent in toughness and environmental stress cracking resistance, but is inferior in rigidity, heat resistance and paintability, and because of its crystallinity, molding shrinkage is large, and molded products such as sink marks and warpage It has a drawback that defects are likely to occur. Usually, polyolefins are often used by adding an inorganic filler such as calcium carbonate for the purpose of eliminating such disadvantages. However, even if a filler is added, the degree of improvement of these disadvantages may be insufficient depending on the use. Further, a composition filled with an inorganic filler has a problem that a metal such as a cylinder, a screw, and a mold of an extruder or a molding machine is worn during the production or molding of the composition.

On the other hand, aromatic vinyl-based polymers are amorphous, so that no problems occur during molding with polyolefins, but they have poor chemical resistance and are inherently brittle. And the impact strength may be insufficient.

For the purpose of improving such disadvantages of the polyolefin or the aromatic vinyl polymer, an attempt has been made to add an aromatic vinyl polymer represented by polystyrene to the polyolefin, for example, JP-A-49-76989.
No. 52-32990, No. 52-50390, No. 52-89155,
Nos. 57-174239, 58-101142, 61-157551,
The technology can be found in 61-285209 and the like. However, in these techniques, the modulus of elasticity or the glass transition temperature of the aromatic vinyl polymer is not sufficiently high, and the degree of improvement of the defect of polyolefin is insufficient.

[Problems to be solved by the invention]

As described above, thermoplastic resin compositions comprising a polyolefin and an aromatic vinyl-based polymer are known, but the resulting composition does not sufficiently improve the disadvantages of the polyolefin or the aromatic vinyl-based polymer. Did not.

The object of the present invention is a composition comprising a polyolefin and an aromatic vinyl polymer, and furthermore, rigidity, impact strength,
An object of the present invention is to provide a thermoplastic resin composition having excellent heat resistance and chemical resistance and excellent moldability.

[Means for solving the problem]

That is, the present invention relates to (A) a modified polyolefin of a thermoplastic resin having at least one functional group selected from the group consisting of amino group, hydroxyl group and ester group.
90% by weight, and (B) 30 to 69% by mole of an aromatic vinyl monomer group, 30 to 50% by mole of a maleimide monomer group and 1 to 20% by mole of an unsaturated dicarboxylic anhydride monomer group Is a thermoplastic resin composition comprising 90 to 10% by weight of a maleimide-based copolymer. The resin composition has high rigidity and heat resistance because of the high rigidity and glass transition temperature of the maleimide-based copolymer. Moreover, it is characterized by excellent impact strength, moldability, paintability and chemical resistance.

The method for producing the maleimide-based copolymer used in the present invention is not particularly limited, and for example, as one method,
It can be produced by radical copolymerization of an aromatic vinyl monomer, a maleimide-based monomer and an unsaturated dicarboxylic anhydride monomer in the presence or absence of a rubbery polymer.

Specific examples of the aromatic vinyl monomer include styrene and α-
There are methylstyrene, vinyltoluene, t-butylstyrene and the like, and specific examples of the maleimide monomer include maleimide, N-methylmaleimide, N-ethylmaleimide,
N-propylmaleimide, N-hexylmaleimide, N
-Cyclohexylmaleimide, N-phenylmaleimide, N-tolylmaleimide and the like. Specific examples of unsaturated dicarboxylic anhydride monomers include maleic anhydride, methylmaleic anhydride, 1,2-dimethylmaleic anhydride, Examples include ethyl maleic acid and phenyl maleic anhydride. The maleimide-based copolymer may contain other copolymerizable monomer groups. Specific examples of other copolymerizable monomers include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, cyclohexyl (meth) acrylate, decyl (meth) acrylate, There are acrylic monomers such as octadecyl (meth) acrylate, hydroxyethyl (meth) acrylate, methoxyethyl (meth) acrylate, and glycidyl (meth) acrylate; vinyl cyanide monomers such as acrylonitrile and methacrylonitrile; These can be used alone or in combination. Here, for example, methyl (meth) acrylate means methyl acrylate or methyl methacrylate.

The method for radical copolymerization of these monomers is not particularly limited, and any known radical copolymerization method can be applied.

In the present invention, a rubbery polymer can be contained in the maleimide-based copolymer for the purpose of further increasing the impact strength of the resin composition of the present invention. The rubbery polymer is a polymer of a conjugated diene monomer such as butadiene, isoprene, chloroprene or a copolymerizable monomer such as an aromatic vinyl monomer and / or an acrylic monomer with a conjugated diene monomer. It is a copolymer with a monomer.

As another method for producing the maleimide copolymer used in the present invention, an aromatic vinyl monomer, an unsaturated dicarboxylic anhydride monomer and other copolymers in the presence or absence of a rubber-like polymer can be used. Examples of the method include a method in which a copolymer obtained by copolymerizing a reactive monomer is reacted with ammonia or a primary amine to imidize an acid anhydride residue. The imidization reaction between a polymer substance having an acid anhydride residue in a polymer chain and an amine compound is known, and for example, according to the method disclosed in JP-B-61-26936 or JP-B-62-8456. By reacting a molecular substance with an amine compound, a maleimide-based copolymer having a target imide group can be produced.

Examples of the primary amine used in the imidation reaction include methylamine, ethylamine, propylamine, butylamine, hexylamine, cyclohexylamine,
Decylamine, aniline, toluidine, naphthylamine, chlorophenylamine, dichlorophenylamine,
Bromophenylamine, dibromophenylamine and the like.

The method of the imidation reaction is arbitrary, and the reaction can be carried out in a solution state, a bulk molten state, or a suspension state using an autoclave. It is also possible to carry out the reaction in a molten state using a melt kneading device such as a screw extruder.

The solvent used in the solution reaction is arbitrary, and examples thereof include ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ethers such as tetrahydrofuran and 1,4-dioxane; aromatic hydrocarbons such as toluene and xylene; and dimethylformamide. , Dimethylsulfoxide, N-methyl-2-pyrrolidone, and the like.

The imidization reaction temperature is preferably in the range of 50 to 350 ° C.,
A range of -300 ° C is particularly preferred.

The imidation reaction does not necessarily require the presence of a catalyst, but if used, trimethylamine, triethylamine, tributylamine, N, N-dimethylaniline, N, N-
Tertiary amines such as diethylaniline are preferred.

The maleimide-based copolymer used in the present invention contains 30 to 69 mol% of an aromatic vinyl monomer group and 30 of a maleimide-based monomer group.
~ 50 mol%, unsaturated dicarboxylic anhydride monomer groups 1-20
It consists of mol%, other copolymerizable monomer groups and rubbery polymer which are optionally added. More preferred ranges are 40 to 65 mol% of an aromatic vinyl monomer group, 30 to 45 mol% of a maleimide monomer group, and 3 to 15 mol% of an unsaturated dicarboxylic anhydride monomer group. Maleimide monomer group
When the amount is less than 30 mol%, the heat resistance of the obtained composition is inferior,
If it exceeds 50 mol%, moldability will be poor. If the amount of the unsaturated dicarboxylic anhydride monomer group is less than 1 mol%, the mechanical properties of the resin composition obtained by mixing with the modified polyolefin are poor, and if it exceeds 20 mol%, the thermal stability is poor.

The polyolefin used in the present invention is ethylene,
Propylene, butene-1, pentene-1, hexene-
1,3-methylbutene-1, 4-methylpentene-1,
It is a homopolymer of an α-olefin monomer such as heptene-1, octene-1, or a random or block copolymer of these monomers, and a polymer having the properties of a thermoplastic resin. Further, a mixture of these polymers may be used.

The method for producing these polyolefins is not particularly limited, and known techniques can be applied as they are.

Furthermore, the modified polyolefin of the thermoplastic resin used in the present invention has at least one functional group selected from the group consisting of an amino group, a hydroxyl group and an ester group for the purpose of improving the compatibility with the maleimide-based copolymer. Functional group-modified polyolefin. Further, a mixture of the functional group-modified polyolefin and an unmodified polyolefin may be used.

The method for producing the functional group-modified polyolefin is not particularly limited,
For example, it is produced by copolymerization of a monomer having a functional group and an α-olefin monomer. The monomer having a functional group used herein is, for example, a monomer having an ester group such as an acrylic monomer used for producing a maleimide copolymer, vinyl formate, vinyl acetate, vinyl propionate and the like. There are aliphatic vinyl ester monomers and the like,
Examples of monomers having an amino group include allylamine, aminoethyl (meth) acrylate, and aminopropyl (meth)
There are acrylates, aminostyrenes and the like, and monomers having a hydroxyl group include allyl alcohol, hydroxyethyl (meth) acrylate, hydroxystyrene,
And hydroxyphenylmaleimide. However, these copolymers have properties of a thermoplastic resin.

As another method for producing a functional group-modified polyolefin, the monomer having a functional group and a radical initiator are mixed with an unmodified polyolefin of a thermoplastic resin in a molten state, and the monomer is added to a polyolefin chain. A method of adding can be presented. This method is known as a reactive processing method, and the reaction can be carried out using a known melt kneading apparatus such as a screw extruder or a co-kneader. Examples of the radical initiator used here include benzoyl peroxide, lauroyl peroxide, dicumyl peroxide, peroxides such as di-t-butyl peroxide, azo compounds such as azobisisobutyronitrile, and 2,3. -Diphenyl-2,3-dimethylbutane, 3,4-diphenyl-3,4-dimethylhexane and the like can be used.

The resin composition of the present invention comprises 10 to 90% by weight of a modified polyolefin of a thermoplastic resin and 90 to 10% by weight of a maleimide copolymer. If the modified polyolefin content of the thermoplastic resin is less than 10% by weight, the resulting resin composition will have poor impact strength and chemical resistance. When the amount of the maleimide-based copolymer is less than 10% by weight, the obtained resin composition is inferior in heat resistance, rigidity, paintability and dimensional stability.

In order to produce the resin composition of the present invention, a modified polyolefin of a thermoplastic resin and a maleimide-based copolymer are melt-kneaded to form a composition, but the melt-kneading method is not particularly limited, and a screw extruder may be used. Known melt kneading apparatuses such as a Banbury mixer, a co-kneader, and a mixing roll can be arbitrarily applied.

In the present invention, in addition to the modified polyolefin of the thermoplastic resin and the maleimide-based copolymer, other polymers can be mixed to form a composition.As such a polymer, polypropylene, polyethylene, or the like can be used. Polyolefin, polystyrene, acrylonitrile-styrene resin,
There are styrene-based resins such as ABS resin and MBS resin, methacrylic resin, polyamide, polycarbonate resin, vinyl chloride resin, polyethylene terephthalate, polybutylene terephthalate, and the like. In particular, polyolefin, styrene-based resin, and polyamide are preferably used.

Further, the resin composition of the present invention may contain an inorganic filler as required. Specific examples of the inorganic filler used include glass fiber, alumina fiber, reinforcing fiber such as carbon fiber, talc, clay, silica, mica, calcium carbonate, barium sulfate, titanium oxide, zinc oxide, wollastonite, and glass. Fillers such as flakes are included.

〔Example〕

Hereinafter, the present invention will be described in more detail with reference to Examples, but all parts and percentages used in Examples and Comparative Examples are by weight.

〔sample〕

(1) Functional group-modified polyolefin (A) Polypropylene J-340P10 manufactured by Mitsui Petrochemical Industries, Ltd.
After mixing 0 parts, 1 part of allylamine and 0.2 parts of 3,4-diphenyl-3,4-dimethylhexane with a Hensiel mixer, the mixture was supplied to a PCM-30 type twin screw extruder manufactured by Ikegai Iron Works Co., Ltd. The pellets were obtained by melt-kneading at ℃. Let the obtained pellet be (A-1).

(A-2), (A-3) and (A-4) were obtained in the same manner as (A-1) except that allylamine was changed to the following other monomers.

(A-2): 4-hydroxyphenylmaleimide (A-3): methyl acrylate In addition, polypropylene JHC (A-5) manufactured by Mitsui Toatsu Co., Ltd. was used as an unmodified polyolefin.

(2) Maleimide copolymer (B) 100 parts of styrene was charged into an autoclave equipped with a stirrer, the inside of the system was replaced with nitrogen gas, and then heated to a temperature of 80 ° C. A solution prepared by dissolving 67 parts of maleic anhydride and 0.2 part of benzoyl peroxide in 300 parts of methyl ethyl ketone was added thereto over 8 hours. After the addition, the mixture was further stirred at a temperature of 80 ° C. for 4 hours to obtain a styrene-maleic anhydride copolymer. Add 1.2 parts of triethylamine and 52 parts of aniline, and add
For 7 hours. The reaction solution was cooled to room temperature, poured into 300 parts of vigorously stirred methanol, and the precipitated polymer was separated by filtration and dried, and a maleimide copolymer (B-1) was obtained.
I got

The reaction was carried out in the same manner as in (B-1) except that the amount of aniline added was changed to 64 parts, to obtain (B-2).

The compositions of (B-1) and (B-2) were quantified by ¹³ C-NMR. Here, St represents a styrene group, PM1 represents an N-phenylmaleimide group, and MAH represents a maleic anhydride group.

(B-1) St: 59.5 mol% PM1: 33.0 mol% MAH: 7.5 mol% (B-2) St: 59.5 mol% PM1: 40.5 mol% (3) Other polymer (C) (C-1) Olefin-based elastomer: Tuffmer P-0680 manufactured by Mitsui Petrochemical Co., Ltd. (4) Inorganic filler (D) (D-1) Calcium carbonate: Whiten SB manufactured by Shiraishi Calcium Co., Ltd. Examples 1-6 and Comparative Examples 1-3 (A ), Component (B), component (C) and component (D) are mixed in a Henschel mixer at the ratios shown in Table 1, and then supplied to a PCM-30 type twin screw extruder to be melt-kneaded at 280 ° C. did. A molded article was manufactured by injection molding using the obtained pellet, and was subjected to physical property evaluation.

 The physical property evaluation method is as follows.

(1) Heat resistance According to ASTM D-648, a 1/4 inch thick injection molded product was used to measure the heat deformation temperature under a load of 18.6 kg / cm ² . However, there is no annealing.

(2) Impact strength In accordance with ASTM D-256, a notched Izod impact strength of a 1/4 inch thick injection molded article was measured. The ambient temperature is 23 ° C.

(3) Rigidity The flexural modulus was measured according to ASTM D-790. The ambient temperature is 23 ° C.

(4) Dimensional stability ASTM-1 dumbbells were molded, and the molding shrinkage in the longitudinal direction was measured. However, the molding temperature was 260 ° C. and the mold temperature was 60 ° C.

(5) Paintability A square plate of 120 x 120 x 2 mm is formed, at a temperature of 23 ° C and a relative humidity of 5
After leaving it in a 5% atmosphere for 24 hours, it was painted using a spray gun. Paint is Lecrac # 72 manufactured by Fujikura Kasei Co., Ltd.
M and thinner used # 702. After the coating, the coating was left for 24 hours, a grid was drawn at 1 mm intervals, and a grid test was performed.
The results were evaluated in percentage of peeled eyes.

(6) Chemical resistance ASTM-1 dumbbell was molded, and the dumbbell was fixed in a bow shape to a two-point support jig so that the maximum deflection was 50 mm and the maximum strain was 1.5%. Yamaha genuine brake oil was applied to the dumbbell test piece, and the time until the test piece fractured was measured under the condition of an ambient temperature of 23 ° C.

(7) Appearance A molded article having a rib and a boss on the back surface and having an opening was molded with a 5-ounce injection molding machine, and the appearance of the molded article was visually measured.な い indicates that there is no practical problem, △ indicates that improvement is required, and x indicates that delamination occurs.

 Table 1 shows the test results.

[Effects of the Invention] As shown in Table 1, the resin composition according to the example of the present invention is obtained by mixing a functional group-modified polyolefin and a specific maleimide-based copolymer having an unsaturated dicarboxylic anhydride monomer group. The strength, rigidity and stiffness of the compositions of Comparative Examples 1 and 2 were
It can be seen that the dimensional stability, paintability, chemical resistance and appearance were greatly improved. In addition, it can be seen that the resin composition of the present invention is superior in heat resistance, strength, rigidity, dimensional stability, and paintability as compared with the resin composition of Comparative Example 3 not using the maleimide-based copolymer. Further, as shown in Example 7, it can be seen that even if an inorganic filler such as calcium carbonate is added to the resin composition of the present invention, its properties are not impaired.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) C08L 23/00-23/26 C08L 35/06 C08L 51/06 C08L 63/00-63/10

Claims (1)

(57) [Claims] 1. A thermoplastic resin having one or more functional groups selected from the group consisting of amino groups, hydroxyl groups and ester groups, (A) a modified polyolefin of 10 to 90% by weight, and (B) an aromatic vinyl monomer. 90 to 90% by weight of a maleimide-based copolymer containing 30 to 69% by mole of a monomer group, 30 to 50% by mole of a maleimide-based monomer group, and 1 to 20% by mole of an unsaturated dicarboxylic anhydride monomer group % Of a thermoplastic resin composition.