JPH1036619A - Blow-moldable rubber-reinforced styrenic resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a blow-moldable rubber-reinforced styrenic resin composition which has excellent blow moldability and can give moldings having excellent appearance. SOLUTION: This composition contains 100 pts.wt. rubber-reinforced styrenic resin (A), 0.1-20 pts.wt. styrenic resin (B) having a weight-average molecular weight of 500,000 or above or 0.01-10 pts.wt. polytetrafluoroethylene (C) having a weight-average molecular weight of 25,000,000 or above or contains 100 pts.wt. A and at least two members selected from among 0.1-20 pts.wt. styrenic resin (B) having a weight-average molecular weight of 500,000 or above, 0.01-10 pts.wt. polytetrafluoroethylene (D) and 0.1-20 pts.wt. (meth)acrylic ester polymer (E).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rubber-reinforced styrenic resin composition for blow molding, which is capable of producing a molded article having excellent blow moldability and excellent appearance.

[0002]

2. Description of the Related Art The blow molding method is widely used for molding hollow containers, mainly for polyolefin resins. In recent years, automotive parts such as air spoilers, bumpers, glove box doors, and instrument panels; OA equipment and office supplies such as computer housings, workstations, cabinet door panels, and desk tops; refrigerator door panels; In the field of home appliances such as equipment panels, and housing-related products such as doors, wall panels, and kitchen door panels, this blow molding method uses engineering resin for the purpose of measurement, resource saving, and cost reduction. It has begun to be used for large blow molded articles having a double wall structure.

Recently, AB which is a rubber-reinforced styrenic resin
S resin has also been used as a material for this large blow molded product. However, when molding a large part, the strength of the parison (a hollow cylindrical resin in a molten and softened state) is not sufficient, and It is easy to draw down, and even if it can be molded, it has the drawback that the width of molding conditions is narrow, such as insufficient temperature dependence of drawdown resistance, and it is necessary to improve blow moldability. In the blow molding method, the blow pressure of the parison is at most 5 to 10 kg.
/ Cm ² , the injection molding is excellent in appearance, and even an ABS resin capable of forming a sophisticated molded product is inferior in appearance and a sophisticated molded product cannot be obtained by conventional blow molding. In order to solve these problems, recently, a high transfer blow molding technique has been developed, and an ABS resin is used to obtain a fine blow-molded article having excellent appearance and elaborateness (for example, JP-A-7-108534). Gazette). As described above, by using the high transfer blow molding technique, a blow molded article of an ABS resin having excellent appearance and fineness can be obtained. Therefore, application development is expected, and the appearance and fineness are further improved. There is a demand for large blow molded products. However,
The conventional ABS resin may not be able to sufficiently satisfy this demand.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a rubber-reinforced styrene resin composition for blow molding, which is capable of producing a molded article having excellent blow moldability and excellent appearance.

[0005]

According to the present invention, there is provided a rubber-reinforced styrene resin composition for blow molding comprising (A) 100 parts by weight of a rubber-reinforced styrene resin and the following (B) or (C): (Hereinafter, also referred to as “first composition”). (B) Styrenic resin having a weight average molecular weight of 500,000 or more.
1 to 20 parts by weight (C) 0.01 to 10 parts by weight of polytetrafluoroethylene having a weight average molecular weight of 25,000,000 or more

The present invention also relates to a blown rubber comprising (A) 100 parts by weight of a rubber-reinforced styrene resin and containing at least two members selected from the following groups (B), (D) and (E). Rubber-reinforced styrenic resin composition for molding (hereinafter also referred to as "second composition", and the first and second compositions are collectively referred to simply as "rubber-reinforced styrenic resin composition of the present invention")
Is provided. (B) Styrenic resin having a weight average molecular weight of 500,000 or more.
1 to 20 parts by weight (D) 0.01 to 10 parts by weight of polytetrafluoroethylene (E) a polymer mainly composed of (meth) acrylate (hereinafter also referred to as “(meth) acrylate based polymer”) ) 0.1-20 parts by weight

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION In the first composition of the present invention, ABS is used.
The addition of a relatively high molecular weight component (B) or (C) to (A) a rubber-reinforced styrene resin such as a resin improves the blowdown resistance of the parison.
In addition, in the second composition, regardless of the molecular weight of the polymer, the combination of at least two of the components (B), (D) and (E) specified in the second composition allows (D) to (D) to
Even if the component (E) has a relatively low molecular weight, the drawdown resistance can be improved.

The rubber-reinforced styrene resin (A) used in the present invention includes, for example, ABS resin, HIPS resin,
MBS resin, AES resin, AAS resin, rubber-reinforced acrylic resin such as rubber-reinforced methyl methacrylate-styrene copolymer, and the like. These (A) rubber-reinforced styrenic resins can be used alone or in combination of two or more. (A) The rubber-reinforced styrene resin is preferably an ABS resin, AES
Resin and AAS resin.

The rubber-reinforced styrenic resin (A) of the present invention comprises an aromatic vinyl compound or another vinyl monomer which can be copolymerized with an aromatic vinyl compound in the presence of a rubbery polymer. A graft polymer obtained by polymerizing a monomer component consisting of a polymer, or a mixture of the graft polymer and a (co) polymer of the monomer component. Examples of the rubbery polymer used here include polybutadiene, polyisoprene, butyl rubber, styrene-butadiene copolymer (preferably having a styrene content of 5 to 60% by weight), styrene-isoprene copolymer, and acrylonitrile-butadiene copolymer. Coalesce, ethylene-α-olefin copolymer, ethylene-
α-olefin-polyene copolymer, silicone rubber,
Acrylic rubber, butadiene- (meth) acrylate copolymer, styrene-butadiene block copolymer,
Examples include styrene-isoprene block copolymer, styrene-butadiene block copolymer, hydrogenated styrene-butadiene block copolymer, hydrogenated butadiene-based polymer, and ethylene-based ionomer.

The styrene-butadiene block copolymer and the styrene-isoprene block copolymer include those having an AB type, an ABA type, a taper type, and a radial teleblock type structure. The hydrogenated butadiene-based polymer includes, in addition to the hydride of the block copolymer, a styrene block and a hydride of a styrene-butadiene random copolymer block, and a 1,2-vinyl bond in polybutadiene. 20% by weight
It includes the following blocks and hydrides of polymers composed of polybutadiene blocks having a 1,2-vinyl bond content of more than 20% by weight. These rubbery polymers can be used alone or in combination of two or more.

The aromatic vinyl compound used in the rubber-reinforced styrene resin includes styrene, t-butylstyrene, α-methylstyrene, p-methylstyrene, divinylbenzene, 1,1-diphenylstyrene, N, N- Diethyl-p-aminoethylstyrene, N, N-diethyl-p-aminomethylstyrene, vinylpyridine, vinylxylene, monochlorostyrene, dichlorostyrene, monobromostyrene, dibromostyrene, fluorostyrene, ethylstyrene, vinylnaphthalene and the like. And styrene and α-methylstyrene are particularly preferred. These aromatic vinyl compounds are used alone or in combination of two or more. The amount of the aromatic vinyl compound used is
It is preferably 20 to 100% by weight, more preferably 30 to 90% by weight, particularly preferably 40 to 8% by weight in the monomer component.
If it is less than 20% by weight, sufficient moldability cannot be obtained.

Other vinyl monomers include vinyl cyanide compounds such as acrylonitrile and methacrylonitrile; methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, amino acrylate, hexyl acrylate, octyl acrylate and 2-ethylhexyl. Acrylates such as acrylate, cyclohexyl acrylate, dodecyl acrylate, octadecyl acrylate, phenyl acrylate, and benzyl acrylate; methyl methacrylate, ethyl methacrylate, propyl methacrylate;
Butyl methacrylate, amino methacrylate, hexyl methacrylate, octyl methacrylate, 2-ethylhexyl methacrylate, cyclohexyl methacrylate, dodecyl methacrylate, octadecyl methacrylate, phenyl methacrylate, methacrylic acid esters such as benzyl methacrylate; maleic anhydride, itaconic anhydride, citraconic anhydride, etc. Unsaturated acid anhydrides; unsaturated acids such as acrylic acid and methacrylic acid; maleimide, N-methylmaleimide, N-butylmaleimide;
Α, such as N- (p-methylphenyl) maleimide, N-phenylmaleimide and N-cyclohexylmaleimide;
an imide compound of β-unsaturated dicarboxylic acid; an epoxy group-containing unsaturated compound such as glycidyl methacrylate or allyl glycidyl ether; an unsaturated carboxylic acid amide such as acrylamide or methacrylamide;
Amino group-containing unsaturated compounds such as aminomethyl methacrylate, aminoether methacrylate, aminopropyl methacrylate and aminostyrene; 3-hydroxy-1-propene, 4-hydroxy-1-butene, cis-4-hydroxy-2- Butene, trans-4-hydroxy-2-
Butene, 3-hydroxy-2-methyl-1-propene,
Examples thereof include a hydroxyl group-containing unsaturated compound such as 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, and hydroxystyrene; and an oxazoline group-containing unsaturated compound such as vinyl oxazoline. A vinyl cyanide compound and / or (meth) acrylic are preferable. An acid ester and / or an imide compound (including an imidation type described later). These other vinyl monomers can be used alone or in combination of two or more.

In place of the above-mentioned copolymerization of the imide compound, an unsaturated anhydride may be copolymerized and then imidized (completely or partially). The amount of these other vinyl monomers to be used is preferably 80 to 0% by weight, more preferably 70 to 10% by weight, particularly preferably 60 to 20% by weight in the monomer components.

Preferred rubber-reinforced styrenic resins are those obtained by polymerizing an aromatic vinyl compound and a vinyl cyanide compound and, if necessary, other copolymerizable vinyl monomers in the presence of a rubbery polymer. A rubber-reinforced styrene-based resin and an aromatic vinyl compound, a vinyl cyanide compound, and, if necessary, a styrene-based resin comprising another copolymerizable vinyl-based monomer.

The graft ratio of the rubber-reinforced styrene resin is 5 to 200% by weight, preferably 10 to 150% by weight. When the graft ratio is less than 5% by weight, fish eyes are frequently generated, and the appearance and impact resistance are poor.
If it exceeds 00% by weight, appearance and fluidity are poor. The graft ratio is measured by the following method. Here, the graft ratio refers to a ratio of a copolymer component directly graft-bonded to the rubber-like polymer with respect to the amount of rubber in the rubber-reinforced styrene resin. 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-reinforced styrene-based resin is put into acetone at room temperature, sufficiently stirred, and the insoluble matter (w) is obtained. On the other hand, the amount of the rubbery polymer in the insoluble matter (w) is
It can be calculated based on the polymerization recipe. With the calculated total amount of the rubbery polymer as R, the graft ratio is determined from the following equation. Graft amount (% by weight) = [(w−R) / R] × 100

Further, regarding the matrix component excluding the rubber component of the insoluble portion of the rubber-reinforced styrene resin, the weight average molecular weight in terms of polystyrene of the tetrahydrofuran-soluble portion is less than 500,000, preferably 50,000 to 300,000, and Preferably it is 70,000 to 200,000. If it is less than 50,000, the impact resistance of the obtained resin composition may be reduced, while if it exceeds 300,000, the moldability may be reduced. The weight average molecular weight of the matrix component can be easily adjusted by appropriately selecting the type and amount of the chain transfer agent and the polymerization initiator and the polymerization temperature.

Next, (B) the styrene-based resin is prepared by mixing an aromatic vinyl compound or a monomer component comprising an aromatic vinyl compound and another vinyl monomer copolymerizable with the aromatic vinyl compound. ) Styrene (co) obtained by polymerization
It is a polymer. Here, the aromatic vinyl compound includes all the aromatic vinyl compounds used in the component (A). Further, the other vinyl monomers include all other vinyl monomers used in the component (A). Of the other vinyl monomers, acrylonitrile is preferred. (B) Specific examples of the styrene-based resin include an acrylonitrile-styrene copolymer (AS resin) and an acrylonitrile-styrene-α-methylstyrene copolymer.

(B) The styrene resin has a weight-average molecular weight in terms of polystyrene of 50 parts which is soluble in tetrahydrofuran.
10,000 or more, preferably 750,000 or more, more preferably 10
0 to 8 million. The drawdown resistance in the blow molding method is largely dependent on the molecular weight of a styrenic resin such as an AS resin, and when the weight average molecular weight is 500,000 or more,
Good drawdown resistance. If the weight average molecular weight of the (B) styrene resin is less than 500,000, the effect of improving drawdown resistance is not sufficient. The temperature dependency of the drawdown resistance becomes better when the weight average molecular weight of a styrene resin such as an AS resin is increased, but the melt viscosity of the entire system may become too high and the moldability may be reduced. 8,000,000 or less is preferable. In particular, when a small amount of a styrene resin such as an ultrahigh molecular weight AS resin having a weight average molecular weight of 1,000,000 or more is added, the temperature dependency is reduced and the melt viscosity of the entire system is not greatly affected, so that molding is possible.

(B) The blending amount of the styrene resin is (A)
0.1 to 100 parts by weight of rubber-reinforced styrene resin
20 parts by weight, preferably 1 to 10 parts by weight. 0.1
If the amount is less than part by weight, the drawdown resistance is not improved, and the temperature dependency is not particularly improved. On the other hand, if it exceeds 20 parts by weight, the melt viscosity becomes too high, and the moldability and the appearance of the molded product are reduced. The (B) styrene-based resin is usually compounded and mixed with (A) the rubber-reinforced styrene-based resin, but (A) the styrene-based resin may be produced and mixed at the time of polymerization of the rubber-reinforced styrene-based resin.

Next, the polytetrafluoroethylene of the components (C) to (D) may be a copolymer of tetrafluoroethylene homopolymer, vinylidene fluoride, hexafluoropropylene, or the like. Preferably, it is a tetrafluoroethylene homopolymer. (C) ~
The polytetrafluoroethylene as the component (D) can be obtained by a known polymerization method such as emulsion polymerization, suspension polymerization and the like. (C) ~
The polytetrafluoroethylene as the component (D) has a solubility index of 6.2, which is the lowest among polymers, and is not compatible with other polymers. By blending in the system resin, the drawdown resistance can be remarkably improved.
Here, the weight average molecular weight of (C) polytetrafluoroethylene is 25,000,000 or more, preferably 25,000,000 to 100,000,000. On the other hand, the weight average molecular weight of the component (D) is
It is preferably at least 500,000, more preferably at least 1,000,000, particularly preferably at least 10,000,000, more preferably from 25,000,000 to 100,000,000. By adding the component (C) and the component (D), the elasticity at the time of blow molding of the rubber-reinforced styrene resin (A) such as an ABS resin, the so-called ballistic effect is improved, and the drawdown resistance is improved.

However, when the component (C) is used alone with respect to the component (A) as in the first composition, the weight average molecular weight of the component (C) must be 25,000,000 or more. If the amount is less than 25,000,000, the elasticity at the time of blow molding of the rubber-reinforced styrene resin (A) such as an ABS resin, that is, the so-called ballistic effect is not improved, so that the drawdown resistance is not improved. Also, as in the second composition,
When at least two of the components (B), (D) and (E) are used in combination, the effects of the present invention can be obtained without any particular limitation on the weight average molecular weight of the component (D). (C)
The weight average molecular weight of the polytetrafluoroethylene of the components (D) to (D) is a value calculated by the following equation in accordance with ASTM D4491. logMw = 27.5345-12.405D (wherein, Mw represents a weight average molecular weight, and D represents a standard specific gravity.)

The compounding amount of polytetrafluoroethylene as the components (C) to (D) is 0.01 to 10 parts by weight, preferably 0.05 to 10 parts by weight, per 100 parts by weight of the rubber-reinforced styrene resin (A). 5 parts by weight. If the amount is less than 0.01 part by weight, the drawdown resistance is not improved. On the other hand, if it exceeds 10 parts by weight, the elasticity at the time of processing becomes too large, the occurrence of melt fracture is large, and the appearance of the molded product is deteriorated.

Next, the (E) (meth) acrylate polymer used in the second composition is used as the (meth) acrylate polymer.
The acrylic acid ester is, for example, an acrylic acid ester and a methacrylic acid ester. If necessary, other vinyl monomers copolymerizable as a copolymerization component may be used. Examples of the other vinyl monomers include the above-mentioned vinyl cyanide compounds and aromatic vinyl compounds, and acrylonitrile and styrene are preferable. (E) The amount of the (meth) acrylate in the (meth) acrylate based polymer is preferably 10 to 100% by weight, more preferably 20 to 100% by weight, and particularly preferably 30 to 99% by weight. It is. (E) Specific examples of the (meth) acrylate polymer include polymethyl methacrylate and methyl methacrylate-butyl acrylate copolymer. (E) The (meth) acrylate polymer can be obtained by known polymerization methods such as emulsion polymerization, suspension polymerization, bulk polymerization, and solution polymerization. Particularly preferred polymerization methods are emulsion polymerization and solution polymerization. It is.

(E) The weight average molecular weight in terms of polystyrene of the (meth) acrylate polymer is preferably 500,000 or more, more preferably 1,000,000 or more, and particularly preferably 1,000,000 to 10,000,000. When the weight average molecular weight is less than 500,000, the elasticity during blow molding of the rubber-reinforced styrene-based resin (A) such as ABS resin, that is, the so-called ballistic effect is not improved, so that the drawdown resistance is hardly improved. On the other hand, when the weight average molecular weight exceeds 10,000,000, the ballast effect becomes too large, melt fracture is likely to occur, and the appearance of the molded product is deteriorated.

The amount of the (E) (meth) acrylate polymer is 0.1 to 20 parts by weight, preferably 0.5 to 20 parts by weight, per 100 parts by weight of the rubber-reinforced styrene resin (A).
10 parts by weight. If the amount is less than 0.1 part by weight, the drawdown resistance is not improved, while if it exceeds 20 parts by weight, the melt viscosity increases, the moldability decreases, and the rigidity of the obtained molded article decreases. Preferred combinations of the components (B), (D) and (E) are (D) / (B), (D) /
(E), (D) / (B) / (E), and when used in this combination, more excellent effects of the present invention can be obtained.

The rubber-reinforced styrene resin composition of the present invention is obtained by kneading the above components (A) to (E) and, if necessary, various thermoplastic resins, various fillers, and various additives. Manufactured. As the kneading method, an extruder,
There is a method using a roll, a Banbury mixer, a kneader, or the like. A preferable method is a method using an extruder, and examples of the extruder include a single-screw extruder and a twin-screw extruder. When kneading various components using the above-described kneading method, all components may be kneaded at once, some components may be kneaded first, and the remaining components may be added at once or divided. It may be kneaded.

Here, various thermoplastic resins include polyolefin resins such as polyethylene, polypropylene, polybutene-1, ethylene-vinyl acetate copolymer (EVA) and ethylene-vinyl alcohol copolymer (EVOH); polyamides Resin; thermoplastic polyester resin;
Polycarbonate resin; wholly aromatic polyester; PP
S; LCP; vinyl chloride resin (PVC); polysulfone; polyether ether ketone; (modified) polyphenylene ether resin; polyoxymethylene (POM); acrylic resin such as polymethyl methacrylate (PMMA) and rubber reinforced polymethyl methacrylate [However,
(Excluding the component (E)]; polyurethane; urea resin and the like. These thermoplastic resins are the composition 1 of the present invention.
The amount is preferably 100 parts by weight or less, more preferably 50 parts by weight or less based on 00 parts by weight.

The above various fillers include glass fiber, carbon fiber, metal fiber, glass beads, wollastonite, milled fiber of glass, rock filler, glass flake, calcium carbonate, talc, mica, kaolin, and sulfuric acid. One or a combination of fillers such as barium, graphite, molybdenum disulfide, magnesium oxide, zinc oxide whiskers, potassium titanate whiskers, glass balloons, ceramic balloons and the like can be used. Among these state materials, the shape of glass fiber and carbon fiber is 6 to
Those having a fiber diameter of 60 μm and a fiber length of 30 μm or more are preferred. These fillers comprise the composition 100 of the present invention.
It is usually used in a range of 1 to 200 parts by weight based on parts by weight. Examples of the additives include known colorants, pigments, weathering agents, antistatic agents, antioxidants, flame retardants, heat aging inhibitors, plasticizers, antibacterial and antifungal agents, and the like.

The rubber-reinforced styrenic resin composition of the present invention can be used to form various molded articles by blow molding. By the way, the blow molding method is a molding method in which a parison (tubing-like molding material) is sandwiched between molds, and air is blown into the parison, whereby the parison surface is pressed against the mold to form a hollow product. However, since the blow pressure of the parison is as low as 5 to 10 kg / cm ² at the maximum, the transfer of the mirror surface or the grain surface of the mold surface is not sufficient, and the appearance of the molded product is inferior to the injection molded product, and the elaborateness is high. There is a disadvantage that a molded article cannot be obtained. What improves this disadvantage is a high transfer blow molding technique. This technique is a method in which the mold surface temperature in the above-mentioned parison surface pressing step is equal to or higher than the Vicat softening temperature of the molding material of the parison, and the transfer of the mold surface is sufficient, the appearance of the molded article is excellent, and the elaborateness is high. A molded product can be obtained. In the high transfer blow molding technique, it is not necessary to maintain the entire process at or above the Vicat softening temperature, and the mold temperature has reached or exceeded the Vicat softening temperature of the molding material at the stage when the parison surface was pressed against the mold surface. Just do it.

Here, as a method of heating the mold surface temperature to be equal to or higher than the Vicat softening temperature of the molding material, for example, a method in which a space is provided on the back side of the mold surface and a heating medium is injected into the space, Radiant heating the back side of the mold, heating the back side of the mold surface by approaching or contacting a heater, radiant heating the mold surface before parison insertion, mold surface before parison insertion, A method of heating by approaching or contacting a heater, and the like. Especially,
In the above-mentioned heating method, the rubber-reinforced styrene-based resin composition of the present invention can obtain much higher high transferability. The above-mentioned mold surface temperature is set to be equal to or higher than the Vicat softening temperature in order to obtain a good molding appearance, and more preferably, the Vicat softening temperature + 10 ° C. or higher to the Vicat softening temperature + 60.
° C is good. As described above, the rubber-reinforced styrene resin composition of the present invention is useful for blow molding, particularly for the above-mentioned high transfer blow molding.

[0031]

The present invention will now be described more specifically with reference to examples. In the examples, parts and% are based on weight unless otherwise specified. Further, in the examples, granulation of pellets, measurement of physical properties, blow molding method, drawdown resistance, appearance of the molded product is carried out by the following method, and the resin material used is as follows. Prepared.

[0032] In granulating extruder and extrusion conditions below pellets were granulated pellets of each sample. Extruder: Nakatani Machinery Co., Ltd., NVC Screw diameter: 55 mm, L / D = 32 Temperature; Setting 230-270 ° C

Blow Molding Method Using a blow molding machine with an accumulator, square bottles having an average thickness of about 2 mm, a length of 25 cm, a width of 10 cm and a width of 2 cm were formed. Blow molding machine; IPB-E, manufactured by Ishikawajima-Harima Heavy Industries, Ltd.
P-55 Molding temperature: 220 ° C for cylinder, accumulator, and die Mold set temperature; 60 ° C Cooling time; 60 seconds Exhaust time; 20 seconds Blow air pressure; 6 kg / cm ²

High draw-down type flow tester (cylinder diameter = 11 mm,
(Orifice outer diameter = 10 mm, orifice inner diameter = 1 mm)
Temperature, 230 ° C or 250 ° C, load 50kg
After extruding 0.5 cc of the resin, the diameter of the hanging resin is measured with a laser, and the time until the maximum diameter becomes 80% is determined as the drawdown time. The drawdown resistance is determined to be better as the drawdown time is longer. Appearance of blow-molded article The surface condition (large dent) of the blow- bin molded article was visually observed and judged. ；: Good (in a state where there is almost no dent at first glance) ×; inferior (in a state where there are many dents at first glance) Melt fracture parison of parison was visually observed, and the presence or absence of melt fracture was observed.

Resin material ABS resin-1; ABS resin consisting of 58% styrene, 24% acrylonitrile and 18% polybutadiene rubber (graft rate = 55%, weight average molecular weight of matrix component = 130,000) ABS resin-2 An ABS resin having a styrene content of 47%, an acrylonitrile content of 20%, an N-phenylmaleimide content of 15%, and a polybutadiene rubber content of 18% (graft rate = 55%, weight average molecular weight of matrix component =
150,000) ABS resin-3; styrene content 42%, acrylonitrile content 22%, N-phenylmaleimide content 10%, α
-Methylstyrene content 8%, polybutadiene rubber content 1
ABS resin composed of 8% (graft ratio = 50%, weight average molecular weight of matrix component = 140,000) ABS resin-4; styrene content 22%, acrylonitrile content 20%, α-methylstyrene content 40%, polybutadiene rubber content 18 % ABS resin (graft ratio = 50%, weight average molecular weight of matrix component = 17)
Ten thousand)

AS resin-1; weight average molecular weight 5,000,000, styrene content 70%, acrylonitrile content 30%
AS resin-2 consisting of: AS resin-2; AS resin having a weight average molecular weight of 750,000, styrene content of 70% and acrylonitrile content of 30% AS resin-3; weight average molecular weight of 80,000 and styrene content of 7
AS resin consisting of 0% and acrylonitrile content of 30%

PTFE resin-1; weight average molecular weight 4,0
100,000 polytetrafluoroethylene resin PTFE resin-2; polytetrafluoroethylene resin with weight average molecular weight of 1,000,000 PTFE resin-3; polytetrafluoroethylene resin with weight average molecular weight of 50,000 PMMA resin-1; weight average molecular weight 145 PMMA resin composed of 80% methyl methacrylate and 20% butyl acrylate PMMA resin-2; PMMA resin composed of 80% methyl methacrylate and 20% butyl acrylate having a weight average molecular weight of 750,000 PMMA resin-3; PMMA resin with a weight average molecular weight of 80,000 and 80% methyl methacrylate and 20% butyl acrylate

Examples 1 to 11 The above resin materials were selected, combined and pelletized by the above method, and the drawdown resistance and the appearance of blow-molded products were evaluated. The results are shown in Tables 1 and 2. Each of the compositions of the present invention (Examples 1 to 11) has clearly excellent drawdown resistance, and also has an excellent appearance of a blow molded product.

COMPARATIVE EXAMPLE 1 Pellets were formed according to the above-mentioned method using only the ABS resin-1, and the drawdown resistance and the appearance of blow-molded articles were evaluated. Table 3 shows the results. Obviously, the drawdown resistance is poor, and the appearance of the blow molded product is also poor. Comparative Examples 2 to 5 Comparative Examples 2 to 4 are an AS resin and a PTFE resin, respectively.
The weight average molecular weight of the PMMA resin is out of the range of the present invention. Table 3 shows the results. Obviously, the drawdown resistance is poor, and the appearance of the blow molded product is also poor. Comparative Example 5
The amount of the AS resin is out of the range of the present invention. Table 3 shows the results
Shown in Although the drawdown resistance was extremely good, it is not shown in Table 3, but the surface appearance of the molded product was insufficient due to severe melt fracture.

[0040]

[Table 1]

[0041]

[Table 2]

[0042]

[Table 3]

[0043]

According to the present invention, blow moldability is excellent,
A rubber-reinforced styrene-based resin composition for blow molding, which can produce a molded article having excellent appearance, is obtained.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location C08L 33:10)

Claims (2)

[Claims] 1. A rubber-reinforced styrene resin composition for blow molding comprising (A) 100 parts by weight of a rubber-reinforced styrene resin and the following (B) or (C). (B) Styrenic resin having a weight average molecular weight of 500,000 or more.
1 to 20 parts by weight (C) 0.01 to 10 parts by weight of polytetrafluoroethylene having a weight average molecular weight of 25,000,000 or more 2. A rubber reinforced for blow molding comprising (A) at least two kinds selected from the following groups (B), (D) and (E) based on 100 parts by weight of a rubber-reinforced styrene resin. Styrene resin composition. (B) Styrenic resin having a weight average molecular weight of 500,000 or more.
1 to 20 parts by weight (D) 0.01 to 10 parts by weight of polytetrafluoroethylene (E) 0.1 to 20 parts by weight of a polymer mainly composed of (meth) acrylate ester