JPH0764963B2 - Thermoplastic resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thermoplastic resin composition comprising a fibrous material reinforced imidized copolymer. More specifically, an imide obtained by reacting a copolymer obtained by polymerizing a monomer mixture containing an aromatic vinyl monomer and an unsaturated dicarboxylic acid anhydride in the presence of a rubbery polymer with a primary amine if necessary. The present invention relates to a thermoplastic resin composition in which a thermoplastic resin containing a mixture of a modified copolymer and a rubber-modified aromatic vinyl copolymer as an essential component is reinforced with a fibrous material selected from carbon fiber and aramid fiber.

Conventionally, in the case of glass fiber reinforcement, aromatic vinyl monomer,
A composition with an unsaturated dicarboxylic acid anhydride and a copolymer composed of other vinyl monomers is known (Japanese Patent Laid-Open No. Sho 48).
-88189). The composition of the copolymer and glass fiber obtained by copolymerizing these unsaturated dicarboxylic acid anhydrides, the acid anhydride group due to the unsaturated dicarboxylic acid anhydride is present in the copolymer chain, so that Not only against water but also against heat, it easily undergoes a chemical change and is easily decomposed, which causes severe restrictions during injection or extrusion processing. Also, the processed product may be exposed to water or steam or exposed to high temperatures. In that case, there is a drawback that it causes deterioration of mechanical properties, particularly impact strength.

U.S. Pat. No. 3,632,791 discloses a composition of a glass fiber and a copolymer of 40 to 95% by weight of an aromatic vinyl monomer, 5 to 25% by weight of a maleimide and 0 to 35% by weight of another monomer. Is disclosed. However, in such a composition, since the maleimide content is low, the affinity with the copolymer on the glass fiber surface is not sufficient, and there is no substance such as a rubber-modified copolymer that increases impact strength. However, there is a drawback that the impact resistance is insufficient.

The present invention has conducted diligent research to improve the above-mentioned drawbacks when not only glass fibers but also carbon fibers and / or aramid fibers are used, and as a result, a monomer containing an aromatic vinyl monomer and an unsaturated dicarboxylic acid anhydride is obtained. An essential component is a mixture of an imidized copolymer obtained by reacting a primary amine with a copolymer obtained by polymerizing a monomer mixture if necessary in the presence of a rubbery polymer, and a rubber-modified aromatic vinyl copolymer. By mixing one or more kinds of fibers selected from carbon fiber and aramid fiber with the thermoplastic resin to have high rigidity,
In addition, it was the first time to succeed in obtaining a thermoplastic resin composition having excellent heat resistance, impact resistance, hot water resistance and dimensional stability.

That is, the present invention is as follows: Component A: rubber polymer 0-40% by weight, aromatic vinyl monomer 40-75% by weight, unsaturated dicarboxylic acid anhydride 25-
50% by weight and vinyl monomers copolymerizable with them 0 to
A polymer obtained by copolymerizing 60 to 100% by weight of a monomer mixture of 30% by weight is reacted with a primary amine to form an acid anhydride group.
10 to 90% by weight of an imidized copolymer obtained by converting 80 to 100% by mole into an imide group, and component B: 5 to 80% by weight of a rubber-like polymer, and 40 to 80% by weight of an aromatic vinyl monomer. A graft copolymer obtained by copolymerizing 20 to 95% by weight of a monomer mixture consisting of 0 to 40% by weight of a vinyl cyanide monomer and 0 to 40% by weight of a vinyl monomer copolymerizable therewith. 90% by weight, C component: 40 to 80% by weight of aromatic vinyl monomer, 0 to 40% by weight of vinyl cyanide monomer, and 0 to 40% by weight of vinyl monomer copolymerizable therewith. Polymer 0-80% by weight
60 to 95 parts by weight of a thermoplastic resin containing and 5 or more kinds of fibers selected from carbon fiber and aramid fiber 5
It is a thermoplastic resin composition obtained by mixing 40 parts by weight to 40 parts by weight.

The composition of the present invention is used for applications requiring the above-mentioned properties, for example, automobile interiors, exteriors, engine room parts, electric / electronic device parts, industrial machine parts, and kitchen appliances using hot water and the like. Suitable for

The thermoplastic resin of the present invention may be composed of only the A component and the B component, and even if it is mixed with an aromatic vinyl copolymer of the C component in the range of 80% by weight or less, the present invention Since the excellent properties of the thermoplastic resin are not deteriorated, it has an advantage that a large amount of inexpensive aromatic vinyl copolymer can be blended.

First, the A-component polymer and its production method will be described. The monomer mixture used comprises 40 to 75% by weight of aromatic vinyl monomers, 25 to 50% by weight of unsaturated dicarboxylic acid anhydrides and 0 to 30% by weight of vinyl monomers copolymerizable therewith. If desired, the rubbery polymer can be used up to 40% by weight, based on the monomer mixture. If the content of the aromatic vinyl monomer in the monomer mixture is less than 40% by weight, the moldability and dimensional stability characteristic of the aromatic vinyl compound are impaired. Further, if the unsaturated dicarboxylic acid anhydride is less than 25% by weight, the affinity with the carbon fiber and the aramid fiber is not sufficient, so that the interface between the resin and the fiber easily peels off,
Since fracture occurs from there, mechanical strength such as tensile strength and impact strength of the composition decreases. If the unsaturated dicarboxylic acid anhydride content is less than 25% by weight, the heat resistance will also decrease.
In the present invention, the unsaturated dicarboxylic acid anhydride content is 25% by weight or more, whereby the adhesive strength at the interface between the resin and the fiber is increased, the mechanical strength is improved, and the heat resistance is also improved. On the other hand, when the amount of unsaturated dicarboxylic acid anhydride exceeds 50% by weight, the copolymer composition becomes brittle and the moldability remarkably deteriorates.

The aromatic vinyl monomer constituting the component A is a styrene monomer such as styrene, α-methylstyrene, vinyltoluene, t-butylstyrene, chlorostyrene, or a substituted monomer thereof. Is particularly preferable.

Examples of unsaturated dicarboxylic acid anhydrides include anhydrides such as maleic acid, itaconic acid, citraconic acid, and aconitic acid.
Maleic anhydride is especially preferred.

Further, as vinyl monomers copolymerizable with these, acrylonitrile, methacrylonitrile, vinyl cyanide monomers such as α-chloroacrylonitrile, acrylic acid ester monomers such as methyl acrylate ester, ethyl acrylate ester, Methacrylic acid ester monomers such as methyl methacrylic acid ester, ethyl methacrylic acid ester,
There are vinylcarboxylic acid monomers such as acrylic acid and methacrylic acid, and acrylic acid amides and methacrylic acid amides. Among these, acrylonitrile, methacrylic acid ester, acrylic acid and methacrylic acid are preferred.

As the rubber-like polymer, a butadiene polymer, a copolymer of a vinyl monomer copolymerizable with butadiene, an ethylene-propylene copolymer, an ethylene-propylene-diene copolymer, a block of butadiene and aromatic vinyl A copolymer, an acrylic acid ester polymer, a copolymer of an acrylic acid ester and a vinyl monomer copolymerizable therewith, and the like are used. If the rubber component in the component A polymer exceeds 40% by weight, it is not preferable in terms of heat resistance and moldability.

The primary amine used in the imidization reaction may be in either anhydrous or aqueous state, and examples of the primary amine include alkylamines such as methylamine, ethylamine, butylamine and cyclohexylamine, and chloro or Examples thereof include aromatic amines such as bromine-substituted alkylamine, aniline, tolylamine and naphthylamine, and halogen-substituted aromatic amines such as chloro- or bromine-substituted aniline.

When the imidization reaction is carried out in a solution state or a suspension state, it is preferable to use an ordinary reaction vessel, for example, an autoclave, and when it is carried out in a bulk molten state, an extruder equipped with a devolatilization device may be used. A catalyst may be present during imidization, and for example, a tertiary amine or the like is preferably used.

The temperature of the imidization reaction is about 80-350 ° C, preferably 1
It is from 00 to 300 ° C. If the temperature is lower than 80 ° C, the reaction rate is slow and the reaction takes a long time, which is not practical. On the other hand, when the temperature exceeds 350 ° C, the physical properties are deteriorated due to thermal decomposition of the polymer.

The amount of primary amine used is preferably 0.8 to 1.05 molar equivalent with respect to the unsaturated dicarboxylic acid anhydride. If it is less than 0.8 molar equivalent, the imidized copolymer will have a large amount of acid anhydride groups, and the thermal stability and the hot water resistance will decrease, which is not preferable.

Next, the component B and its manufacturing method will be described. The rubber-like polymer used as the component B is butadiene homopolymer or a polymer composed of a vinyl monomer copolymerizable therewith, ethylene-propylene copolymer, ethylene-propylene-diene copolymer or acrylic acid ester homopolymer or homopolymer. There is a polymer composed of a vinyl monomer copolymerizable with.

The aromatic vinyl monomer used as the component B is a styrene monomer such as styrene, α-methylstyrene, vinyltoluene, t-butylstyrene, chlorostyrene, or a substituted monomer thereof. And α-
Monomers such as methylstyrene are particularly preferred.

Examples of the vinyl cyanide monomer include acrylonitrile, methacrylonitrile, α-chloroacrylonitrile, etc., and acrylonitrile is particularly preferable.

As vinyl monomers copolymerizable with these, acrylic acid esters such as methyl acrylic acid ester, ethyl acrylic acid ester and butyl acrylic acid ester, and methacrylic acid ester monomers such as methyl methacrylic acid ester and ethyl methacrylic acid ester. , Vinyl carboxylic acid monomers such as acrylic acid and methacrylic acid, acrylic acid amides, and methacrylic acid amides. Of these, methyl methacrylic acid ester, acrylic acid and methacrylic acid are particularly preferable.

The method for producing the graft copolymer of the component B is a rubber-like polymer 5-80.
A monomer mixture comprising 40 to 80% by weight of an aromatic vinyl monomer, 0 to 40% by weight of a vinyl cyanide monomer, and 0 to 40% by weight of a vinyl monomer copolymerizable with these in the presence of 1% by weight. 20
Obtained by graft-copolymerizing about 95% by weight. For the polymerization, any known polymerization technique can be adopted, and examples thereof include aqueous heterogeneous polymerization such as suspension polymerization and emulsion polymerization, bulk polymerization, solution polymerization, and precipitation polymerization of the produced polymer in a non-solvent.

Next, the C component and its manufacturing method will be described. Aromatic vinyl monomers used as the C component include styrene and α-
It is a styrene monomer such as methylstyrene, vinyltoluene, t-butylstyrene, chlorostyrene and the like, and a substituted monomer thereof, and among these, styrene and α-methylstyrene are particularly preferable.

Examples of the vinyl cyanide monomer include acrylonitrile, methacrylonitrile, α-chloroacrylonitrile, etc., and acrylonitrile is particularly preferable.

Vinyl monomers copolymerizable with them include acrylic acid ester monomers such as methyl acrylic acid ester, ethyl acrylic acid ester and butyl acrylic acid ester, and methacrylic acid ester monomers such as methyl methacrylic acid ester and ethyl methacrylic acid ester. Examples thereof include monomers, vinylcarboxylic acid monomers such as acrylic acid and methacrylic acid, acrylic acid amides, methacrylic acid amides, acenaphthylene, N-vinylcarbazole, N-alkyl-substituted maleimides, and N-aromatic-substituted maleimides.

The content of at least one fiber selected from carbon fiber and aramid fiber in the resin composition of the present invention is 5 to 40% by weight. When the content of these fibers is less than 5% by weight, the rigidity and dimensional stability of the obtained molded product are not sufficiently improved, and when it exceeds 40% by weight, molding, particularly injection molding becomes extremely difficult.

Aramid fibers are polyamide fibers in which an aromatic chain is introduced into the molecular chain, and examples of this polymer include poly-m-xylylene adipamide, poly-p-benzamide, poly-p-phenylene terephthalamide and poly-m-. Examples include phenylene isophthalamide.

The physical properties of the fiber composition vary greatly depending on the shape of the fiber and the surface treatment state, similarly to various known fiber-reinforced compositions. Even in the fiber-reinforced composition of the present invention, the fiber length is 0.
The thickness is preferably 3 mm or more, and silane coupling agents such as aminosilane and epoxysilane, titanium coupling agents and the like can be used.

The composition of the present invention is a mixture of a thermoplastic resin containing a mixture of an imidized copolymer and a rubber-modified aromatic vinyl copolymer as an essential component, and at least one fiber selected from carbon fiber and aramid fiber. However, the mixing method is not particularly limited, and known means can be used. Examples of the means include a Banbury mixer, a tumbler mixer, a Henschel mixer, a mixing roll, a single-screw or twin-screw extruder, and the like. As a mixing form, there are methods of obtaining a composition by ordinary melt mixing, multi-stage melt kneading using master pellets and the like, solution blending and the like.

In addition, the composition of the present invention further stabilizer, flame retardant, plasticizer,
It is also possible to add lubricants, ultraviolet absorbers, colorants and fillers such as talc, silica, clay, mica and calcium carbonate.

Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded. All parts and% in the examples are expressed on a weight basis.

Experimental Example (1) Production of Component A 60 parts of styrene and 50 parts of methyl ethyl ketone were charged into an autoclave equipped with a stirrer, the system was replaced with nitrogen gas, and the temperature was raised to 85 ° C. to give 40 parts of maleic anhydride. A solution of 0.15 parts of benzoyl peroxide dissolved in 250 parts of methyl ethyl ketone was continuously added over 8 hours. The temperature was maintained at 85 ° C for a further 3 hours after the addition. As a result of sampling a part of the viscous reaction liquid and quantifying the unreacted monomer by gas chromatography, the polymerization rate was 98% styrene,
It was 98% maleic anhydride. The copolymer solution obtained here was added with 0.95 equivalents of aniline 36.1 to maleic anhydride.
Parts and 0.3 parts of triethylamine were added and reacted at 140 ° C. for 7 hours. Add 200 parts of methyl ethyl ketone to the reaction solution,
The mixture was cooled to room temperature, poured into 1500 parts of vigorously stirred methanol, precipitated, filtered and dried to obtain an imidized polymer. C-13
According to NMR analysis, aniline was almost 100% reacted in the reaction of the acid anhydride group to the imide group. This was designated as Polymer A.

Experimental Example (2) Production of Component A Styrene 60 was added to the same autoclave as in Experimental Example (1).
Parts, 100 parts of methyl ethyl ketone, and 10 parts of polybutadiene cut into small pieces were charged and stirred at room temperature for one day to dissolve the rubber, then the system was replaced with nitrogen gas and the temperature was raised to 85 ° C. A solution prepared by dissolving 40 parts of maleic anhydride and 0.15 part of azobisisobutyronitrile in 200 parts of methyl ethyl ketone was continuously added over 8 hours. After that, the same operation as in Experimental Example (1) was performed. The polymerization rate was 98% styrene and 99% maleic anhydride. The reaction rate of aniline in the reaction of the acid anhydride group to the imide group was about 100% as in Experimental Example (1). This was designated as Polymer B.

Experimental Example (3) Production of Component A Styrene 60 was added to the same autoclave as in Experimental Example (1).
Parts, acrylonitrile 10 parts, methyl ethyl ketone 50 parts, a solution of maleic anhydride 30 parts and azobisisobutyronitrile 0.15 parts dissolved in methyl ethyl ketone 250 parts was continuously added in 9 hours, and 27.0 parts of aniline was used. Except for this, the same operation as in Experimental Example (1) was performed. The polymerization rate was 99% styrene, 92% acrylonitrile, and 96% maleic anhydride. As with the experimental example (1), aniline is almost
It was 100% reactive. This was designated as Polymer C.

Experimental Example (4) Production of component B Polybutadiene latex 143 parts (solid content 35%, polymerization average particle size 0.35μ, gel content 90%), potassium stearate 1 part, sodium formaldehyde sulfoxylate 0.1
Parts, tetrasodium ethylenediaminetetraacetic acid 0.03 parts, ferrous sulfate 0.003 parts and water 150 parts 50 parts
After heating to ℃, 50 parts of a monomer mixture consisting of 70% styrene and 30% acrylonitrile, 0.2 part of t-dodecyl mercaptan, 0.15 part of kyumen hydroperoxide are continuously added over 6 hours, and after addition, 65 ° C. The temperature was raised to 0 and polymerization was carried out for 2 hours. The polymerization rate is from gas chromatographic analysis.
Reached 97%. After adding an antioxidant to the obtained latex, coagulation with calcium chloride, washing with water and drying were performed to obtain a graft copolymer as a white powder. This was designated as Polymer D.

Experimental Example (5) Production of component C 60 parts of α-methylstyrene, 10 parts of styrene, 30 parts of acrylonitrile, 2.5 parts of potassium stearate, 0.5 part of t-dodecyl mercaptan and 250 parts of water were heated to 70 ° C. Polymerization was initiated by adding 0.05 part of potassium sulfate. After 7 hours from the start of the polymerization, 0.03 part of potassium persulfate was further added, and the temperature was raised to 75 ° C. and kept for 3 hours to complete the polymerization. The polymerization rate reached 97%. The obtained latex was coagulated with calcium chloride, washed with water and dried to obtain a white powder copolymer. This was designated as Polymer E.

Examples 1 to 4 Polymers A to E obtained in Experimental Examples (1) to (5), 6 mm long PAN-based carbon fiber and 6 mm long aramid fiber (du P
Ont Co., Kevlar K-49) was mixed in a ratio shown in Table 1 by a Henschel mixer, and then extruded by an extruder with a vent to be pelletized. The pellets were molded by an injection molding machine and a physical property test was conducted. The results are shown in Table 1. To the above composition, 2 parts of tristearyl phosphite and 0.5 part of octadecyl 3- (3,5-di-shartybutyl-4-hydroxyphenyl) -propionate were added to 100 parts of the polymer.

Comparative Example 1 The polymer A obtained in the experimental example (1) and the polymer D obtained in the experimental example (4) were mixed in the proportions shown in Table 1 in the same manner as in Examples 1 to 4, In addition, it was molded and the physical properties were measured, and the results are shown in Table 1.

Comparative Examples 2 and 3 Styrene 90 was added in the same autoclave as in Experimental Example (1).
, 150 parts of methyl ethyl ketone, 10 parts of maleic anhydride and 0.15 parts of azobisisobutyronitrile dissolved in 100 parts of methyl ethyl ketone were continuously added over 10 hours, and aniline was used except 9.49 parts. The exact same operation as in Example (1) was performed. Polymerization rate is styrene 95
% And maleic anhydride 99%. Also, as in Experimental Example (1), aniline was almost 100% reacted. This was used as a polymer P, and 6 mm long carbon fibers were mixed in the same manner as in Examples 1 to 4 at the ratio shown in Table 1 and molded to measure the physical properties. Shown in the table.

From Table 1, the composition of the present invention has high rigidity, and significant improvements in impact resistance, heat resistance, hot water resistance and dimensional stability are recognized.

The physical properties were measured by the following methods.

(1) Tensile strength: measured according to ASTM-D651.

(2) Impact strength: Notched Izod strength.

Measured according to ASTM-D256.

(3) Vicat softening point: load 5 kg.

Measured according to ASTM-D1525.

(4) Hot water resistance Test piece (ASTM No. 1 dumbbell) obtained by injection molding at 100 ℃
After being immersed in hot water for 24 hours, it was cooled to room temperature and the tensile strength was measured.

The measured values are shown in Table 1 as [(tensile strength after hot water treatment) / (tensile strength before hot water treatment)] × 100 (%).

(5) Moldability The minimum filling injection pressure (gauge pressure) required for injection molding ASTM No. 1 dumbbell was measured. The molding machine used was IS-50EP manufactured by Toshiba Kikai at a molding temperature of 280 ° C.

(6) Dimensional stability A test piece (ASTM No. 1 dumbbell) obtained by injection molding is at 100 ° C.
After leaving it in a gear oven in an atmosphere for 24 hours, it was cooled to room temperature and the dimension in the vertical direction was measured.

The measured values are shown in Table 1 as [(dimension before heat treatment−dimension after heat treatment) / (dimension before heat treatment)] × 10 ³ .

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location C08L 77/00 (56) References JP-A-58-101141 (JP, A) JP-A-59- 93746 (JP, A) JP 59-187046 (JP, A) JP 59-196355 (JP, A) JP 58-129043 (JP, A) JP 59-191749 (JP, A)

Claims (1)

[Claims] 1. A component: 40 to 75% by weight of an aromatic vinyl monomer, 25 to 50% by weight of an unsaturated dicarboxylic acid anhydride, and copolymerizable with these, based on 0 to 40% by weight of a rubbery polymer. Monomer mixture 60 to 100 consisting of 0 to 30% by weight of vinyl monomer
10% to 90% by weight of an imidized copolymer in which 80% to 100% by mole of an acid anhydride group is converted into an imide group by reacting a primary amine with a polymer obtained by copolymerizing% by weight, and a component B: Aromatic vinyl monomer 40 to 80% by weight, vinyl cyanide monomer 0 to 40% by weight, and vinyl monomer 0 to 40% by weight copolymerizable with them, relative to rubbery polymer 5 to 80% by weight. % Of the graft copolymer obtained by copolymerizing 20 to 95% by weight of a monomer mixture consisting of 10% by weight, C component: 40 to 80% by weight of an aromatic vinyl monomer, and 0% of a vinyl cyanide monomer. -40% by weight and 0 to 40% by weight of a copolymerizable vinyl monomer 0 to 40% by weight
60 to 95 parts by weight of a thermoplastic resin containing and 5 or more kinds of fibers selected from carbon fiber and aramid fiber 5
A thermoplastic resin composition obtained by mixing 40 to 40 parts by weight.