JP3079706B2 - Method for producing graft copolymer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a graft polymer having excellent heat resistance, rigidity and impact resistance.

[0002]

2. Description of the Related Art Various studies have been conducted on maleimide copolymers because of their high heat resistance. For example, a method of copolymerizing N-aromatic substituted maleimide with methyl methacrylate is disclosed in JP-B-43-9753, JP-A-61-14.
JP-A-17-6891, JP-A-61-171708 and JP-A-62-109811 disclose a method of copolymerizing an N-aromatic substituted maleimide with a styrene resin. It is disclosed in JP-A-61-76512 and JP-A-61-276807.

[0003] However, the resin obtained by this method is N-
As the content of the aromatic-substituted maleimide increases, the heat resistance becomes better, but there are problems such as very brittleness, poor processability, and coloring, and a small amount as a heat resistance improver for acrylonitrile / butadiene / styrene (ABS) resin. It is merely used to be added.

On the other hand, N-alkyl-substituted maleimide-olefin copolymers are interesting polymers having properties such as excellent heat resistance, high rigidity and practical mechanical strength, but further improvement in impact strength is desired. It is rare.

Further, Japanese Patent Publication No. 49-12576 discloses a resin composition of a maleimide copolymer and a rubber, which is a simple blend and has little effect of improving bending strength and impact strength. It is.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for producing a graft copolymer having excellent heat resistance, rigidity and impact resistance.

[0007]

The present inventors have made intensive studies in view of this problem, and as a result, have found that a monomer mixture containing an unsaturated dicarboxylic anhydride and an olefin is subjected to radical initiation in the presence of a rubber compound. It has been found that a graft copolymer satisfying the above object can be produced by reacting a copolymer obtained by graft polymerization with a primary alkylamine and imidizing the copolymer, thereby completing the present invention.

The unsaturated dicarboxylic anhydride used in the present invention includes maleic anhydride, citraconic anhydride, itaconic anhydride and the like, and maleic anhydride is preferred.

The olefins of the present invention include ethylene, isobutene, 2-methyl-1-butene, 2-methyl-1-pentene, 2-methyl-1-hexene, 1-methyl-1-heptene, 1-isooctene,
2-methyl-1-octene, 2-ethyl-1-pentene, 2-methyl-2-butene, 2-methyl-2-pentene, 2-methyl-2-hexene and the like, among which heat resistance and mechanical properties From the viewpoint of properties, 1,1-disubstituted olefins, particularly isobutene, are preferred. These are one or two
It can be used in combination of more than one kind.

If necessary, other vinyl monomers may be mixed with the monomer mixture containing the unsaturated dicarboxylic anhydride and the olefin as long as the object of the present invention is not impaired. Absent.

Other vinyl monomers include styrene, α-methylstyrene, vinyltoluene, 1,3-
Butadiene, isoprene and their halogen-substituted derivatives, methacrylates such as methacrylic acid, methyl methacrylate, ethyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, benzyl methacrylate, hydroxyethyl methacrylate, methyl acrylate, acrylic acid Acrylic esters such as ethyl, butyl acrylate, cyclohexyl acrylate, phenyl acrylate and benzyl acrylate; vinyl esters such as vinyl acetate and vinyl benzoate; methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether;
One or more compounds selected from monomers such as vinyl ethers such as butyl vinyl ether and vinyl chloride, vinylidene chloride and acrylonitrile are exemplified.

The rubbery compound used in the production method of the present invention means an elastic or viscous substance having a glass transition temperature of 10 ° C. or lower, preferably 0 ° C. or lower, more preferably -20 ° C. or lower.

The rubbery compounds include diene rubbers such as polybutadiene, styrene / butadiene copolymer, acrylonitrile / butadiene copolymer, methyl methacrylate / butadiene copolymer, polyisoprene, polychloroprene, and hydrogenated products thereof. , Polyethylene, ethylene / propylene / ethylidene norbornene copolymer,
Olefinic elastomers such as butyl rubber, ethylene / vinyl acetate copolymer, ethylene / methyl acrylate copolymer, and acrylic acid such as ethyl acrylate / butyl acrylate copolymer, ethyl acrylate / allyl acrylate copolymer Ethyl-based acrylic rubber, silicones, fluorine-based rubber, urethane-based rubber, ester-based rubber,
Amide rubbers and the like can be mentioned.

The molecular weight of these rubber compounds is not particularly limited, but the molecular weight is more than 1000, especially 1000
It is preferably 0 or more, and these rubbery compounds may be cross-linked, or the properties of the obtained copolymer can be improved by forming a structure such as a core-shell.

Further, it is preferable that these rubber compounds have a double bond, a halogen group, a thiol group, and the like from the viewpoint of producing a graft copolymer.

By selecting the rubber-like compound, the obtained graft copolymer can be imparted with properties such as low-temperature impact resistance, oil resistance, moldability, and weather resistance. Of these, when a diene-based elastomer is used, low-temperature impact properties can be obtained. Copolymer with excellent properties
When an olefin-based elastomer and an acrylic-based elastomer are used, a copolymer having particularly excellent weather resistance and impact resistance can be obtained.

For the polymerization of these copolymers, any of known polymerization methods such as bulk polymerization, bulk-suspension polymerization, solution polymerization, suspension polymerization and emulsion polymerization can be employed.

The polymerization initiators used in these polymerizations include benzoyl peroxide, lauryl peroxide, octanoyl peroxide, acetyl peroxide, di-tert-butyl peroxide, t-butyl cumyl peroxide, dicumyl peroxide, t-butyl peroxide. Organic peroxides such as -oxyacetate and t-butylperoxybenzoate, or 2,2'-azobis (2,4-dimethylvaleronitrile), 2,2'-azobis (2-butyronitrile), , 2'-azobisisobutyronitrile, dimethyl-2,2'-azobisisobutyrate, 1,1'-azobis (cyclohexane-1-
Azo initiators such as carbonitrile).

The polymerization temperature can be appropriately set according to the decomposition temperature of the initiator, but is generally preferably in the range of 40 to 300 ° C.

Solvents usable in the solution polymerization method include benzene, toluene, xylene, ethylbenzene,
Cyclohexane, dioxane, tetrahydrofuran, acetone, methyl ethyl ketone, dimethylformamide,
Isopropyl alcohol, butyl alcohol and the like can be mentioned.

Among these polymerization methods, emulsion polymerization can be carried out, for example, by introducing an unsaturated dicarboxylic anhydride, an olefin, an initiator and the like in the presence of a rubbery latex.

The content of the rubbery compound in the graft copolymer obtained by the above-mentioned polymerization is 3 to 60% by weight,
Preferably 5 to 50% by weight, particularly preferably 10 to 4% by weight.
0% by weight. When the content of the rubbery compound exceeds 60% by weight, the mechanical properties and moldability of the formed copolymer may be deteriorated. When the content is less than 3% by weight, the impact resistance of the obtained copolymer is improved. May be less effective.

The copolymerization ratio of unsaturated dicarboxylic anhydride / olefin in the above graft copolymer is 30 to 70/70 to 30 mol%, and is 45 to 70 in ordinary polymerization regardless of the charged composition. 55/55 to 45 mol%.

According to the present invention, the graft copolymer is reacted with a primary alkylamine to imidize it. This imidization reaction can be performed in a solution state, a suspension state, or a melt state. When imidizing, a catalyst may be present. Examples of the catalyst include tertiary amines. It is preferable that these imidization reactions be performed in nitrogen.

The primary alkylamine used in the imidization reaction includes N-methylamine, N-ethylamine, N-
n-propylamine, Ni-propylamine, Nn
-Butylamine, Ni-butylamine, Ns-butylamine, Nt-butylamine, Nn-pentylamine, Nn-hexylamine, Nn-heptylamine, Nn-octylamine, N -Laurylamine, N
-Stearylamine, N-cyclopropylamine, N-
N such as cyclobutylamine and N-cyclohexylamine
-Alkylamines, and those having an alkyl group having 1 to 4 carbon atoms and a cycloalkyl group having 3 to 6 carbon atoms are preferable from the viewpoint of heat resistance. In particular, N-methylamine, N-ethylamine, N-isopropylamine and N-cyclohexylamine are preferred. These can be used alone or in combination of two or more.
Further, N-aromatic amine, ammonia and the like can be partially used.

When the imidization reaction is carried out in a solution state or a suspension state, it is preferable to use a reactor such as an autoclave. When the imidation reaction is carried out in a molten state, an extruder equipped with a deaerator is used. Is also good. Further, these reactors can be used in combination.

The temperature of the imidation reaction is usually about 30 to 35.
It is carried out at 0 ° C, particularly preferably at 80 to 320 ° C. When the reaction temperature exceeds 350 ° C., the physical properties of the copolymer may be reduced by thermal decomposition. These reaction temperatures can be increased continuously or stepwise.

The imidation ratio can be determined by measurement such as ¹³ C-NMR, IR, and elemental analysis. The imidation ratio in the production method of the present invention is preferably 50% or more, more preferably 80% or more, and particularly preferably 95% or more.

The graft ratio of the copolymer can be determined by solvent extraction or the like. According to the production method of the present invention, (the charged rubber amount−the unreacted rubber amount) / the charged rubber amount × 10
The graft ratio indicated by 0 is 5% or more, preferably 50%.
%, Particularly preferably 80% or more, and an unreacted rubber component may be present in the graft copolymer.

The graft copolymer obtained by the present invention has a melt viscosity of 10 to 10 at a shear rate of 10 ³ sec ^-1 at a temperature of the heat distortion temperature + (100 to 200 ° C.).
About 0000 poise, especially 100 to 10,000
Those having 0 poise are preferred.

The copolymer obtained according to the present invention is:
N-alkyl maleimide / olefin copolymer,
Alternatively, a polymer obtained by imidizing an unsaturated dicarboxylic anhydride / olefin copolymer with a primary amine can be used.

If necessary, polyethylene, polypropylene, polyvinyl chloride, polystyrene, styrene /
Acrylonitrile copolymer, styrene-maleic anhydride copolymer, acrylic resin, imidized acrylic resin, polyamide, polyester, polycarbonate, polyaceta
Homopolymers such as toluene, polyphenylene oxide, polyphenylene sulfide, polysulfone, polyethersulfone, polyamide imide, polyimide, silicone resin, fluorine resin, phenol resin, epoxy resin, diene rubber, olefin rubber, acrylic rubber, etc. , Random, block, graft copolymers, and mixtures or modified products thereof may be used in combination.

Further, various dyes, glass fibers, carbon fibers,
Potassium titanate, asbestos, silicon carbide, ceramic fiber, metal fiber, silicon nitride, barium sulfate, calcium sulfate, kaolin, clay, pyroferrite, zeolite, mica, mica, talc, ferrite, calcium silicate, calcium carbonate, magnesium carbonate Heat stabilizers such as inorganic and organic fillers such as antimony trioxide, zinc oxide, titanium oxide, iron oxide, glass balloon, and aramid fiber, hindered phenol, and organic phosphoric acid ester; benzotriazole; A UV stabilizer such as a hindered amine-based compound, a flame retardant, a flame retardant auxiliary, a foaming agent, an antistatic agent, various lubricants and the like may be added. These additives can be used in various combinations.

The resin obtained in the present invention can be formed into various molded articles, sheets, films, fibers, and the like by known injection molding, extrusion molding, blow molding, foam molding, vacuum molding, and the like. it can. Further, the obtained molded body can be subjected to a treatment such as plating, painting, printing and the like.

[0035]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to the examples.

The confirmation of the produced polymer was carried out by IR measurement, ¹³ C
-Performed by NMR measurement and elemental analysis. The molecular weight of the obtained polymer was determined by gel permeation chromatography.
(HLC-802A, manufactured by Tosoh Corporation) and calculated in terms of polystyrene.

The obtained sample was subjected to 240-320 using a twin-screw extruder (Laboplast Mill, manufactured by Toyo Seiki Co., Ltd.).
C. into pellets, and the obtained pellets are injection-molded using an injection molding machine (Panajection (Matsushita Electric Industrial Co., Ltd.)) at a cylinder temperature of 240 to 350.degree. C. and a mold temperature of 60 to 120.degree. A sample was used.

The heat distortion temperature of the obtained sample was determined by ASTM.
D648 (18.5 kg / cm ² load), flexural strength and flexural modulus were measured according to ASTM D790, and notched impact strength was measured according to ASTM D256.

EXAMPLE 1 208 g of polybutadiene (BR01; manufactured by Nippon Synthetic Rubber Co., Ltd.) and 18 l of dioxane were charged into a 30 l autoclave equipped with a stirrer, nitrogen introduction tube, isobutene introduction tube, thermometer and degassing tube. After dissolving the polybutadiene, 1180 g of maleic anhydride and 24 g of benzyl peroxide (BPO) were charged and purged several times with nitrogen.
1.8 l of liquefied isobutene was charged and polymerized at 70 ° C. for 10 hours.

The reaction content was poured into excess methanol to precipitate a polymer, and the polymer was separated by centrifugation.
It dried at 60 degreeC under reduced pressure for 24 hours. The yield was 2130 g.

1000 g of the obtained polymer was dissolved in dimethylformamide (DMF), and 1.1 mol equivalent of N-methylamine with respect to maleic anhydride group was added thereto, followed by stirring at 60 ° C. for 2 hours. , And 6 at 180 ° C
A time reaction was performed.

A part of the obtained polymer was taken out and ¹³ C-
As a result of NMR measurement, the conversion from maleic anhydride to imide groups was almost 100%. When Soxhlet extraction was performed using toluene as a solvent, the extraction residue was 96%. Characteristic absorption derived from polybutadiene and characteristic absorption derived from imide groups were confirmed by IR analysis of the extraction residue, and the graft copolymer was found Confirmed that it was generated.

The obtained sample was pelletized using a twin screw extruder, and a test piece was prepared by injection molding. Table 1 shows the characteristic evaluation results.

REFERENCE EXAMPLE 1 Maleic anhydride 1180 was added to the reactor described in Example 1.
g, 24 g of BPO and 18 l of dioxane were charged and purged several times with nitrogen, then 1.8 l of liquefied isobutene was charged and polymerization was carried out at 70 ° C. for 10 hours.

The reaction content was poured into excess methanol to precipitate a polymer, and the polymer was separated by centrifugation.
It dried at 60 degreeC under reduced pressure for 24 hours. The yield was 1815 g.

As a result of elemental analysis of the obtained sample, maleic anhydride units in the copolymer were found to be 50 mol%. The obtained sample was dissolved in DMF, and 1.1 mole equivalent of N-methylamine with respect to the maleic anhydride group was added thereto. The mixture was stirred at 60 ° C for 2 hours, and further reacted at 180 ° C for 6 hours. went.

The imidation ratio of the produced polymer was 99% by elemental analysis and ¹³ C-NMR measurement. Several batch polymerizations were performed under the same conditions to prepare samples.

Example 2 Using the same reactor as in Example 1, polybutadiene 46
3 g and 1180 g of maleic anhydride were added to 18 l of toluene.
, 24 g of BPO were charged and purged several times with nitrogen, and then 1.8 l of liquefied isobutene was charged.
The reaction was performed for 2 hours.

The reaction contents were poured into an excess of methanol to precipitate a polymer. After centrifugation, 24 hours at 60 ° C under reduced pressure.
Dried for hours. The yield was 2220 g.

The obtained copolymer is dispersed in toluene,
Imidation was performed using N-methylamine. The imidation ratio was almost 100%. Table 1 shows the results of the characteristic evaluation.

Comparative Example 1 850 g of the sample prepared in Reference Example 1 was uniformly dispersed in a toluene solution of 150 g of polybutadiene, and the polymer was precipitated with an excess of methanol.
After separation and drying, pelletization and injection molding were performed in the same manner, and the characteristics were evaluated. Table 1 shows the obtained results.

Comparative Example 2 Similarly to Comparative Example 1, the sample 800 obtained in Reference Example 1 was obtained.
g and a sample composed of 200 g of polybutadiene were prepared and evaluated for characteristics. Table 1 shows the obtained results.

[0053]

[Table 1]

[0054]

As is clear from the examples, the samples obtained by the production method of the present invention have excellent properties such as excellent heat resistance, impact resistance and rigidity. It is extremely useful in a wide range of applications such as electrical and electronic, precision machinery, housing, food, and medical fields.

Claims (1)

(57) [Claims] A primary alkylamine is added to a copolymer obtained by graft-polymerizing a monomer mixture containing an unsaturated dicarboxylic anhydride and an olefin with a radical initiator in the presence of a rubber compound. A method for producing a graft copolymer, comprising reacting and imidizing.