JP3168652B2 - Thermoplastic resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoplastic resin composition having excellent antistatic properties, impact resistance and fatigue resistance.

[0002]

2. Description of the Related Art Hitherto, styrene resins such as ABS resins have been widely used in the fields of electric / electronics and automobiles because of their excellent moldability, physical properties and mechanical properties. However, this resin is an electrical insulator and is effective as an insulating material,
It has the disadvantage that the charged electricity cannot be leaked, the surface becomes dusty, and the charged electricity interferes with electronic equipment. As a method of improving these disadvantages, a method of kneading an antistatic agent is generally known. However, in this method, since the surface resistivity changes with time and increases, the antistatic effect is not maintained. have.

As a method for improving the durability of the antistatic effect, a method has been proposed in which a polyamide elastomer containing polyethylene glycol and polyamide as main components is blended with an ABS resin. Although this composition has a remarkably improved antistatic sustaining effect as compared with an ABS resin containing the above antistatic agent, it has insufficient fatigue resistance and is required in fields where fatigue is required, for example, It cannot be used as an extension tube of a vacuum cleaner, and its field of use is limited.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and is excellent in antistatic properties, impact resistance, rigidity and fatigue resistance, and can be used in a wide range of applications. An object is to provide a plastic resin composition.

[0005]

The present invention relates to (I) 5 to 50 parts by weight of a polyamide elastomer, and (II)
(A) In the presence of 5 to 60% by weight of a rubbery polymer , (b) 95 to 40% by weight of a monomer component composed of an aromatic vinyl compound or an aromatic vinyl compound and another monomer copolymerizable therewith. % [However, (a) + (b) = 100% by weight]
(Co) polymerized, having an intrinsic viscosity of 0.5-1.3 dl / g (methyl ethyl ketone,
The present invention provides a thermoplastic resin composition containing 95 to 50 parts by weight of a graft copolymer resin (30 ° C.) (provided that (I) + (II) = 100 parts by weight).

As the polyamide elastomer (I) of the present invention, an aminocarboxylic acid or lactam having 6 or more carbon atoms as a hard segment or a diamine component is used.
Assuming that the number of carbon atoms is m and the number of carbon atoms of the dicarboxylic acid component is n
A nylon mn salt (X) with m + n ≧ 12 and a polyol as a soft segment, specifically, poly (alkylene oxide) glycol (Y), and the ratio of the X component in the elastomer is 10 to 95. %, Preferably 20 to 90% by weight, more preferably 80 to 90% by weight. (I)
When the ratio of the X component in the polyamide elastomer is 10
When the amount is less than 95% by weight, the compatibility with the components (a) and (b) is inferior.

If the aminocarboxylic acid having 6 or more carbon atoms is used,
Examples of the lactam or the nylon mn salt (X) having m + n of 12 ≧ 12 include ω-aminocaproic acid, ω-aminoenanoic acid, ω-aminocaprylic acid, ω-aminobergonic acid, ω-aminocapric acid, and 11-aminoundecane. Acids, aminocarboxylic acids such as 12-aminododecanoic acid;
Lactams such as caprolactam and laurolactam; nylon 6,6, nylon 6,10, nylon 6,12,
Nylon 11,6, Nylon 11,10, Nylon 1
Nylon salts such as 2,6, nylon 11,12, nylon 12,10, nylon 12,12.

The poly (alkylene oxide) glycol (Y) includes polyethylene glycol, poly (1,2 and 1,3-propylene oxide) glycol, poly (tetramethylene oxide) glycol, poly (hexamethylene oxide) glycol And a block or random copolymer of ethylene oxide and propylene oxide, and a block or random copolymer of ethylene oxide and tetrahydrofuran. The number average molecular weight of these glycols (Y) is from 200 to
It is 6,000, preferably 250-4,000. Among these glycols (Y), polyethylene glycol is particularly preferably used because of its excellent antistatic property. In the present invention, both ends of the poly (alkylene oxide) glycol (Y) may be aminated or carboxylated. The bond between the component (X) and the component (Y) may be an ester bond or an amide bond corresponding to the terminal group of the component (Y).

In this connection, a third component such as dicarboxylic acid or diamine can be used. The dicarboxylic acid has 4 to 20 carbon atoms, such as terephthalic acid, isophthalic acid, phthalic acid, naphthalene-2,
Aromatic dicarboxylic acids such as 6-dicarboxylic acid, naphthalene-2,7-dicarboxylic acid, diphenyl-4,4-dicarboxylic acid, diphenoxyethanedicarboxylic acid, sodium 3-sulfoisophthalate, 1,4-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid,
Alicyclic dicarboxylic acids such as dicyclohexyl-4,4-dicarboxylic acid, and aliphatic dicarboxylic acids such as succinic acid, oxalic acid, adipic acid, sebacic acid, dodecanedicarboxylic acid, and the like, and mixtures thereof.
In particular, terephthalic acid, isophthalic acid, 1,4-cyclohexanedicarboxylic acid, sebacic acid, adipic acid, and dodecanedicarboxylic acid are preferably used in terms of polymerizability, color tone, and physical properties.

As the diamine, an aromatic, alicyclic or aliphatic diamine is used. Specifically, p-phenylenediamine, m-phenylenediamine, diaminodiphenyl ether, diaminodiphenylmethane and the like as aromatic diamines, and piperazine, diaminodicyclohexylmethane, cyclohexyldiamine and the like as alicyclic diamines, aliphatic diamines Examples thereof include those having 2 to 12 carbon atoms such as hexamethylenediamine, ethylenediamine, propylenediamine, and octamethylenediamine. Among these diamines, preferred is hexamethylene diamine.
(I) The method for synthesizing the polyamide elastomer is not particularly limited, and for example, the methods disclosed in JP-B-56-45419 and JP-A-55-133424 can be used.

(I) Reduced viscosity of polyamide elastomer η _sp / C (0.5 g / 100 m in formic acid solution)
1, measured at 25 ° C.) is from 0.5 to 2.0
It is. Further, since the time of the composition during manufacture and / or molding of the present invention which may cause a decrease in molecular weight due to thermal degradation, reduced viscosity of the component (I) in the final product eta _{sp /} C
Is preferably 0.3 or more. The above (I) polyamide elastomer is used alone or in combination of two or more. (I) The content of the polyamide elastomer is 5 to 50 parts by weight , preferably 5 to 25 parts by weight , more preferably 7 to 20 parts by weight in the thermoplastic resin composition of the present invention. The component (a) is less than 5 parts by weight, poor antistatic performance, whereas when it exceeds 50 parts by weight, undesirably rigidity decreases.

Next, the component (II) of the present invention comprises a graft copolymer obtained by graft polymerization of a monomer component constituting the component (b) in the presence of a rubbery polymer (a). Even if it is a coalescing resin (rubber-modified aromatic vinyl resin), the graft copolymer resin is blended with the (b) (co) polymer obtained by (co) polymerizing the component (b). The resulting blend-type graft copolymer resin may be simply a blend of (a) a rubbery polymer and (b) a (co) polymer.

The rubbery polymer (a) used in the present invention includes, for example, polybutadiene, polyisoprene, styrene-butadiene copolymer (styrene content 5 to 5).
60% by weight), styrene-isoprene copolymer, acrylonitrile-butadiene copolymer, ethylene-α-olefin-based copolymer, ethylene-α-olefin-polyene copolymer, acrylic rubber, butadiene-acrylic copolymer Coalescable, polyisoprene, styrene-butadiene block copolymer, styrene-isoprene block copolymer, hydrogenated styrene-butadiene block copolymer, hydrogenated butadiene-based polymer, and ethylene-based ionomer. In addition, the styrene-butadiene block copolymer and the styrene-isoprene block copolymer include those having an AB type, an ABA type, a tapered type, a radical teleblock type, and the like. further,
The hydrogenated butadiene-based polymer is, in addition to the hydride of the block copolymer, a styrene block and a styrene-butadiene random copolymer block, and a 1,2-vinyl bond content in polybutadiene of 20% by weight. % Or less and a 1,2-vinyl bond content of 20% by weight.
And hydrides of polymers comprising more than one polybutadiene block. These (a) rubbery polymers are:
One type is used alone, or two or more types are used.

(A) The content of the rubbery polymer is (II)
5 to 60% by weight, preferably 5 to 50% by weight,
More preferably, it is 5 to 40 % by weight. If the component (a) is less than 5% by weight , impact resistance is poor, while if it exceeds 60% by weight, rigidity and fatigue resistance are poor.

The monomer component constituting the component (b) is an aromatic vinyl compound or another monomer copolymerizable with the aromatic vinyl compound. As the aromatic vinyl compound constituting the component (b), styrene, t
-Butylstyrene, α-methylstyrene, p-methylstyrene, divinylbenzene, 1,1-diphenylstyrene, N, N-diethyl-p-aminoethylstyrene,
N, N-diethyl-p-aminoethylstyrene, vinylpyridine, vinylxylene, monochlorostyrene, dichlorostyrene, monobromostyrene, fluorostyrene, ethylstyrene, vinylnaphthalene, etc., and especially styrene and α-methylstyrene preferable. These aromatic vinyl compounds may be used alone or in combination of two or more.

Other monomers constituting component (b) include vinyl cyanide compounds such as acrylonitrile and methacrylonitrile; methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, amyl acrylate, hexyl acrylate, and the like.
Acrylic acid esters such as octyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, dodecyl acrylate, octadecyl acrylate, phenyl acrylate and benzyl acrylate;
Methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, amyl methacrylate, hexyl methacrylate, octyl methacrylate, 2-ethylhexyl methacrylate, cyclohexyl methacrylate, dodecyl methacrylate, octadecyl methacrylate, phenyl methacrylate,
Methacrylates such as benzyl methacrylate;
Unsaturated acid anhydrides such as maleic anhydride, itaconic anhydride and citraconic anhydride; unsaturated acids such as acrylic acid and methacrylic acid; maleimide, N-methylmaleimide, N-butylmaleimide, N- (p-methylphenyl) Imide compounds of α- or β-unsaturated dicarboxylic acids such as maleimide, N-phenylmaleimide, N-cyclohexylmaleimide; epoxy compounds such as glycidyl methacrylate and allyl glycidyl ether; unsaturated carboxylic amides such as acrylamide and methacrylamide; acrylic Amines, amino-containing unsaturated compounds such as aminomethyl methacrylate, aminoethyl methacrylate, aminopropyl methacrylate, aminostyrene, 3-hydroxy-1-propene, 4-hydroxy-1-butene, cis-
Hydroxyl-containing unsaturated compounds such as 4-hydroxy-2-butene, trans-4-hydroxy-2-butene, 3-hydroxy-2-methyl-1-propene, 2-hydroxyethyl acrylate, and 2-hydroxyethyl methacrylate; vinyl Examples thereof include oxazoline group-containing unsaturated compounds such as oxazoline. Preferred monomers as component (b) are acrylonitrile, methacrylic acid, methyl methacrylate, maleic anhydride, N-phenylmaleimide, glycidyl methacrylate, 2-hydroxyethyl methacrylate, and the like, and particularly acrylonitrile, N-phenylmaleimide, Hydroxyethyl methacrylate and the like are preferred. These other monomers can be used alone or in combination of two or more.

The amount of component (b) used is 4% in component (II).
It is 0 to 95% by weight, preferably 50 to 95% by weight, and more preferably 60 to 95% by weight. When the use amount of the component (b) is less than 40% by weight, fatigue resistance and rigidity are poor, while when it exceeds 95% by weight, antistatic properties and impact resistance are poor.
The intrinsic viscosity of the methyl ethyl ketone-soluble component in the component (II) of the present invention (measured at 30 ° C. using methyl ethyl ketone as a solvent) is 0.5 to 1.3 dl / g, preferably 0.55 to 1.3 dl / g.
To 1.0 dl / g, more preferably 0.60 to 1.0
dl / g, particularly preferably 0.60 to 0.90 dl / g
It is. If the intrinsic viscosity is less than 0.50 dl / g, the fatigue resistance is poor, while if it exceeds 1.3 dl / g, the antistatic properties and the fatigue resistance are poor. This intrinsic viscosity can be controlled by a chain transfer agent, polymerization time, polymerization temperature, and the like.

The component (II) of the present invention comprises (a) a rubbery polymer comprising a polybutadiene rubber, a styrene-butadiene rubber,
In the case of acrylonitrile-butadiene rubber, emulsion polymerization, solution polymerization, bulk polymerization, etc.
In the case of propylene rubber, ethylene-propylene-non-conjugated diene rubber, block copolymer of styrene-butadiene, hydrogenated diene rubber-like polymer, etc., solution polymerization and bulk polymerization are used, and component (b) is used. Is preferably a rubber-modified aromatic vinyl resin obtained by grafting a monomer component constituting the above.

Further, in order to obtain the (b) (co) polymer composed only of the monomer components, an ordinary well-known polymerization method may be used. That is, emulsion polymerization, suspension polymerization, solution polymerization, and bulk polymerization are used. The polymer after polymerization [(I
The rubber-modified aromatic vinyl resin composed of the component (I) or the (co) polymer composed only of the component (b)] is dried through a recovery process such as coagulation, washing, and desolubilization, and then dried into powder or granules. I do.

When the component (II) is a rubber-modified aromatic vinyl resin, the content of the methyl ethyl ketone-soluble component is preferably 45 to 85% by weight or more, more preferably 50 to 85% by weight. When the component (II) is a rubber-modified aromatic vinyl resin, the graft ratio is usually 30 to 200% by weight, preferably 30 to 150% by weight. The graft ratio is less than 30% by weight, or 2
If it exceeds 00% by weight, the impact resistance tends to decrease, which is not preferable. Here, the graft ratio refers to a ratio of a copolymer component directly graft-bonded to the rubbery polymer with respect to a rubber amount of the graft copolymer. This graft ratio can be controlled by the amount of the polymerization initiator, the polymerization temperature, and the like.

As a specific method of obtaining the graft ratio, first, 2 g of the rubber-modified aromatic vinyl resin is charged into methyl ethyl ketone at room temperature, and the mixture is sufficiently stirred to obtain an insoluble matter (w). On the other hand, the amount of the rubbery polymer in the insoluble matter (w) can be calculated based on the polymerization recipe. With the calculated amount of the rubbery polymer as R, the graft ratio is determined from the following equation. Graft ratio (% by weight) = [(w−R) / R] × 100

The present invention comprises the above-mentioned components (I) and (II) as main components. In addition, for the purpose of improving the performance, a compatibilizer for increasing the compatibility between the components (I) and (II). Can be blended. As a preferred compatibilizer, a styrene-based copolymer obtained by copolymerizing an unsaturated compound having a functional group such as a hydroxyl group, an epoxy group, a carboxyl group, an acid anhydride group, an amino group, or an oxazoline group contained in the component (b) is used. A resin or a copolymer of an α-olefin and the functional group-containing unsaturated compound is preferred. in this case,
The copolymerization amount of the functional group-containing unsaturated compound is 0.5 to 20% by weight, and the amount used is 1 to 3 with respect to the composition of the present invention.
The range is 0% by weight. Examples of the compatibilizer include ethylene-glycidyl methacrylate (GMA) copolymer, preferably ethylene-GMA copolymer with styrene,
Those obtained by graft polymerization of acrylonitrile are exemplified. Specific examples of the compatibilizer include ethylene-GM
Styrene A copolymer, acrylonitrile and those obtained by grafting polymerization, and the like MODIPER® manufactured by NOF Corporation.

Further, the composition of the present invention comprises glass fiber,
Carbon fiber, metal fiber, glass beads, wollastonite,
Rock filler, calcium carbonate, talc, mica, glass flake, kaolin, barium sulfate, graphite, molybdenum disulfide, magnesium oxide, zinc oxide whisker,
Fillers such as potassium titanate whiskers can be used alone or in combination. Among these fillers, the shape of glass fiber or carbon fiber is 6 to 60 μm.
Those having a fiber diameter of m and a fiber length of 30 μm or more are preferred. These fillers are generally used in a range of 5 to 150 parts by weight based on 100 parts by weight of the composition of the present invention.

Further, the composition of the present invention may contain known additives such as a flame retardant, an antioxidant, a plasticizer, a coloring agent, a lubricant, and an antistatic agent. Further, the composition of the present invention, depending on the required performance, other polymers, such as polyethylene, polypropylene, polyamide, polyester, polycarbonate, polysulfone, polyether sulfone, polyphenylene sulfide, liquid crystal polymer, polyvinylidene fluoride, An ethylene-vinyl acetate copolymer or the like can be appropriately blended.

The thermoplastic resin composition of the present invention can be obtained by kneading the components using various extruders, Banbury mixers, kneaders, rolls and the like. A preferred production method is a method using an extruder. When kneading the components, the components may be kneaded at once, or may be kneaded by a multi-stage addition method. The thermoplastic resin composition of the present invention thus obtained is
It can be formed into various molded products by injection molding, sheet extrusion, vacuum molding, heterogeneous molding, foam molding and the like.
The various molded products obtained by the above molding method can be used for various housings of home electric appliances, various parts in the electric / electronic field, the automobile field, housings, miscellaneous goods, etc. by utilizing their excellent properties.

[0026]

The present invention will now be described more specifically with reference to examples. In the examples, parts and% are by weight unless otherwise specified. Various evaluations in the examples are values measured as follows. An antistatic property A disk having a diameter of 100 mm and a thickness of 2 mm is formed, and the temperature is 23 ° C ×
After conditioning for 7 days at a relative humidity of 50%, the surface resistivity was measured using a 4329A super insulation resistance meter manufactured by Yokogawa Hewlett-Packard Company. Impact resistance Measured at 23 ° C. with a 1/8 ″ thickness and notch according to ASTM D256. Flexural modulus was measured according to stiffness ASTM D790. Fatigue resistance Using a train-type vibration vibration fatigue tester under a constant stress. The tensile force was applied repeatedly, and the number of repetitions up to breaking was measured, and the test piece was notched at a constant angle for stress concentration.

Examples 1 to 13 and Comparative Examples 1 to 4 Preparation of Polymers (I) -1 to (I) -4 A polymer block of nylon 6 was obtained by ring-opening polycondensation of ε-caprolactam. After converting both ends to carboxylic acid with adipic acid, polyethylene glycol is added and polymerized,
Polymer (I) -1 which was a polyamide elastomer was obtained. The ratio of the polyamide component to the polyethylene glycol component of the polymer (I) -1 was about 50/50%, and the reduced viscosity measured using formic acid at 25 ° C. and a concentration of 0.5 g / 100 ml was 1.50. there were. Further, the melting point of the polyamide measured by DSC (differential thermal analysis) was 205 ° C.

The following polymer was obtained in the same manner as in Polymer (I) -1. That is, the polymer (I) -2 is an elastomer obtained by shortening the polymerization time of the polymer (I) -1 to have a reduced viscosity of 1.00. The polymer (I) -3 is obtained by converting the polymer (I) -1 to polyamide / polyethylene glycol =
It is an elastomer changed to 40/60%. The polymer (I) -4 is an elastomer obtained by replacing 25% of the polyethylene glycol used in the polymer (I) -1 with polytetramethylene glycol and polymerizing.

Preparation of Polymers (a) -1 to (a) -4 As the component (a) of the present invention, the following rubbery polymers were used.

[0030]

[Table 1]

Preparation of Polymer (a) -5 The following ABC block copolymer was obtained by solution polymerization.
This was hydrogenated to obtain a polymer (a) -5. Block copolymer before hydrogenation; [A block] 5% Styrene content 100% [B block] 85% Styrene content 23.5% Butadiene content 76.5% Vinyl bond content 41% [C block] 10% Styrene content 50% Butadiene content 50% [Block copolymer] Styrene / butadiene 30/70% Here, the C block is a taper block in which styrene gradually increases. After polymerization of the ABC block copolymer, the double bond of the butadiene moiety was
%, And the solvent was removed by steam stripping, followed by drying to obtain a polymer (a) -5.

(Co) polymers (II) -1 to (II) -1
Preparation of 2 A polymer obtained by polymerizing a monomer component constituting the component (b) of the present invention in the presence of the polymer (a) -1 to (a) -5,
And a polymer obtained by polymerizing the monomer component constituting the component (b) without the presence of the polymer (a). Table 2 shows the polymer composition. In Table 2, ST indicates styrene and AN indicates acrylonitrile. (II) component of the solid
Yes viscosity dissolved in it methylethylketone containing no component (a) was measured at 30 ° C.. Also,
With respect to those containing the component (a), the polymer was dissolved in methyl ethyl ketone, the insoluble portion was separated by centrifugation, and the intrinsic viscosity of the dissolved portion was measured under the above conditions.

Preparation of Thermoplastic Resin Composition Each of the above polymers was dried to a water content of 0.1% or less, mixed according to the formulation shown in Table 3, and melt-kneaded using a twin-screw extruder equipped with a vent. Pelletized. The obtained pellet is
The sample was dried to a moisture content of 0.1% or less by a dehumidifying dryer, and a test piece for measuring antistatic property, impact resistance, rigidity and fatigue resistance was molded by injection molding, and evaluated by the above-described evaluation method. Table 3 shows the results.

[0034]

[Table 2]

[0035]

[Table 3]

As apparent from Table 3, the thermoplastic resin compositions of the present invention (Examples 1 to 13) are all excellent in antistatic properties, impact resistance, rigidity and fatigue resistance. Incidentally, the pellets of the compositions of the present invention, the injection molded article, formic acid with methyl ethyl ketone (II) where the intrinsic viscosity of the methyl ethyl ketone-soluble fraction of the components were measured, almost the same value as the intrinsic viscosity shown in Table 2 And no decrease in molecular weight due to the application of heat was observed.

On the other hand, in Comparative Example 1, the intrinsic viscosity of the methyl ethyl ketone-soluble component (II) is out of the range of the present invention, and the impact resistance and fatigue resistance are inferior. Comparative Example 2 shows that the methyl ethyl ketone soluble component (II)
It has a high intrinsic viscosity outside the range of the present invention, and has poor antistatic properties and poor fatigue resistance. Comparative Example 3 is a case where the use amount of the component (I) is small outside the range of the present invention, and the antistatic property is poor. Comparative Example 4 is an example in which the component (a) of the present invention was not used, and the impact resistance was poor.

[0038]

Industrial Applicability The thermoplastic resin composition of the present invention has excellent antistatic properties, impact resistance, rigidity and fatigue resistance, and can be used in a wide range of applications, for example, in the fields of electric / electronics, home electric appliances and office automation equipment. Useful for parts, housings, etc.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tateki Furuyama 2--11-24 Tsukiji, Chuo-ku, Tokyo Japan Synthetic Rubber Co., Ltd. (58) Field surveyed (Int. Cl. ⁷ , DB name) C08L 51 / 04-51/06 C08L 55/02 C08L 77/00

Claims (1)

(57) [Claims] (I) polyamide elastomers 5 to 50
Parts by weight of (b) an aromatic vinyl compound or (b) an aromatic vinyl compound and another monomer copolymerizable therewith in the presence of (a) 5 to 60% by weight of a rubbery polymer. 95 to 40% by weight [provided that (a) + (b)
= 100 wt%] be in (co) polymerization, the intrinsic viscosity of the methyl ethyl ketone soluble matter 0.5~1.3dl / g (methyl ethyl ketone, 30 ° C.) graft copolymer tree is
95 to 50 parts by weight of fat (provided that (I) + (II) = 100)
Parts by weight].