JPH1025394A - Rubber-reinforced styrene resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a rubber-reinforced styrene resin composition for high- transfer blow molding, having excellent blow-moldability and capable of producing a molded article having excellent appearance. SOLUTION: This composition is composed of (A) 100 pts.wt. of a rubber- reinforced styrene resin and at least one kind of polymer selected from (B) 0.1-20 pts.wt. of a styrene resin having a weight-average molecular weight of >=500,000, (C) 0.01-10 pts.wt. of a polytetrafluoroethylene having a weight-average molecular weight of >=500,000 and (D) 0.1-20 pts.wt. of a polymer composed mainly of a (meth)acrylic acid ester and having a weight-average molecular weight of >=500,000. The resin composition is blow-molded by keeping the temperature of the mold surface above the Vicat softening temperature of the composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0005]

According to the present invention, there are provided the following (B) to (A) based on 100 parts by weight of a rubber-reinforced styrene resin.
A composition containing at least one member selected from the group of (D), wherein a rubber-reinforced styrene-based resin composition for high transfer blow molding in which a molding surface is blow-molded at a temperature not lower than the Vicat softening temperature of the composition. It provides things. (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 500,000 or more (D) Polymer having a (meth) acrylic ester having a weight average molecular weight of 500,000 or more as a main component ( Hereinafter, also referred to as “(meth) acrylate polymer”) 0.1 to 20 parts by weight

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION As the rubber-reinforced styrene resin (A) used in the present invention, for example, ABS resin, HIP
Examples include S resin, MBS resin, AES resin, AAS resin, and rubber reinforced acrylic resin such as rubber reinforced methyl methacrylate-styrene copolymer. These (A)
The rubber-reinforced styrene-based resin can be used alone or in combination of two or more.
(A) The rubber-reinforced styrene-based resin is preferably an ABS resin, an AES resin, or an 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 tapered type, and a radial teleblock type. 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.

Instead 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, 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 resin is made of 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.

Next, (C) polytetrafluoroethylene may be a copolymer of vinylidene fluoride, hexafluoropropylene, etc., in addition to a tetrafluoroethylene homopolymer. Preferably, it is a tetrafluoroethylene homopolymer. (C) Polytetrafluoroethylene can be obtained by a known polymerization method such as emulsion polymerization or suspension polymerization. (C) Polytetrafluoroethylene has a solubility index of 6.2, which is the lowest among polymers, and is not compatible with other polymers. By blending, the drawdown resistance can be remarkably improved.
(C) The polytetrafluoroethylene has a weight average molecular weight of 500,000 or more, preferably 1,000,000 or more, more preferably 10,000,000 or more, and particularly preferably 25,000,000 to 100,000,000. If it is less than 500,000, elasticity during blow molding of (A) rubber-reinforced styrene resin such as ABS resin,
Since the so-called ball effect is not improved, the drawdown resistance is not improved. In addition, the weight average molecular weight of (C) polytetrafluoroethylene is 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 the polytetrafluoroethylene (C) is 0.01 to 10 parts by weight, preferably 0.05 to 5 parts by weight, based on 100 parts by weight of the rubber-reinforced styrene resin (A). 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, (D) the (meth) acrylate used in the (meth) acrylate-based polymer is as follows:
For example, acrylic acid esters and methacrylic acid esters, and if necessary, other copolymerizable vinyl monomers may be used as a copolymerization component. Examples of the other vinyl monomers include the above-mentioned vinyl cyanide compounds and aromatic vinyl compounds, and acrylonitrile and styrene are preferable. (D) 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. (D) Specific examples of the (meth) acrylate-based polymer include polymethyl methacrylate and a methyl methacrylate-butyl acrylate copolymer. (D) 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.

(D) The weight average molecular weight in terms of polystyrene of the (meth) acrylate polymer is 500,000 or more, preferably 1,000,000 or more, and more preferably 100 or more.
10,000 to 10 million. When the weight average molecular weight is less than 500,000, the elasticity of the (A) rubber-reinforced styrene-based resin such as an ABS resin at the time of blow molding, that is, the so-called ballistic effect is not improved, so that the drawdown resistance is not improved.
(D) The compounding amount of the (meth) acrylate polymer is 0.1 to 20 parts by weight, preferably 0.5 to 10 parts by weight, based on 100 parts by weight of the rubber-reinforced styrene resin (A). . 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) to (D) are (C) / (B), (C) / (D), and (C) / (B).
/ (D), 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 (D) 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 component (D)]; polyurethane; urea resin. 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 high transfer blow molding. By the way, in the blow molding method, the parison (tubing-like molding material) is sandwiched between molds, and air is blown into the parison, so that the parison surface is pressed against the mold,
This is a molding method for molding hollow articles. However, since the blow pressure of the parison is as low as 5 to 10 kg / cm ² at most,
The transfer of the mirror surface or the textured surface of the mold surface is not sufficient, so that the appearance of the molded product is inferior to that of the injection molded product, and a sophisticated molded product cannot be obtained. What improves this disadvantage is a high transfer blow molding technique. This technique is a method in which the surface temperature of the mold in the step of pressing the parison surface is equal to or higher than the Vicat softening temperature of the molding material of the parison,
The transfer of the mold surface is sufficient, the appearance of the molded product is excellent, and a sophisticated 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 a temperature equal to or higher than the Vicat softening temperature of the molding material, for example, a method of providing a space behind the mold surface and injecting a heating medium 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. In particular, 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, Vicat softening temperature + 10 ° C or higher to Vicat softening temperature + 60 ° C. As described above, the rubber-reinforced styrene resin composition of the present invention is useful for high transfer blow molding.

[0027]

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.

[0028] In granulating extruder and extrusion conditions below pellets were granulated pellets of each sample. Extruder: manufactured by Nakatani Machinery Co., Ltd., NVC screw diameter: 55 mm, L / D = 32 temperature; setting 230-270 ° C Physical property measurement After preparing a test piece with the following injection molding machine and molding conditions, it conforms to each standard. And measured. Injection molding machine; Toshiba Machine Co., Ltd., IS80A temperature; Cylinder set temperature = 220 to 260 ° C Mold temperature; 50 ° C Vicat softening temperature; ASTM D1525

High transfer blow molding method mold; a mold for bottle molding as shown in FIG. 1, having a space behind the molding surface and injecting steam to the space in the mold surface heating step. In the mold surface cooling step, molds each having a mechanism for injecting cooling water were used. In FIG. 1, reference numerals 1a and 1b denote metal bodies having a molding surface, 2a and 2b denote heat insulators, 3 denotes a mold, 3a and 3b.
Is a mold body, 4a and 4b are spaces, 5a and 5b are steam or cooling water supply pipes, and 6a and 6b are steam or cooling water discharge pipes.

IPB-EP-5, manufactured by Ishikawajima-Harima Heavy Industries Co., Ltd., using the above molding die and as a blow molding machine.
Using 0, blow molding was performed under the following molding conditions. Molding conditions: Extruder temperature; 220 ° C. Mold clamping pressure; 15 ton parison blowing pressure; 6 kg / cm ² parison temperature; 230 ° C. Mold clamping holding time; 5 seconds Final temperature of mold surface by heating steam jet heating;
Vicat softening temperature + 32 ° C Pressure of cooling water to be injected; 6 kg / cm ² Final temperature of mold surface cooling; 70 ° C Cooling retention time: 60 seconds

High draw-down resistant flow tester machine (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 (state without dents) △; slightly poor (states at first glance where dents are visible) ×; poor (states with many dents at first glance) Melon fracture of parison visually, 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 PTFE resin-1 consisting of 0% and acrylonitrile content of 30%; polytetrafluoroethylene resin PTFE resin-2 having a weight average molecular weight of 40,000,000; polytetrafluoroethylene resin PTFE resin-3 having a weight average molecular weight of 1,000,000. Polytetrafluoroethylene resin having a weight-average molecular weight of 50,000 PMMA-based resin-1; PMMA-based resin composed of 80% of methyl methacrylate and 20% of butyl acrylate having a weight-average molecular weight of 1,450,000 PMMA-based resin-2; PMMA resin composed of 80% methyl methacrylate and 20% butyl acrylate PMMA resin-3; PMMA resin composed of 80% methyl methacrylate and 20% butyl acrylate having a weight average molecular weight of 80,000

Examples 1 to 13 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 13) clearly has excellent drawdown resistance, and the appearance of blow-molded articles is also excellent.

COMPARATIVE EXAMPLE 1 With only the ABS resin-1, a pellet was formed according to the above-described method, and the drawdown resistance and the appearance of the blow-molded product 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 Example 2 A blow-molded product was obtained in the same manner as in Example 1 except that the final temperature of the molding surface of the mold in Example 1 (Vicat softening temperature (100 ° C) + 32 ° C = 132 ° C) was 70 ° C. . Table 3 shows the results. Despite the excellent drawdown resistance, the appearance of the blow molded product was insufficient. Comparative Examples 3 to 6 Comparative Examples 3 to 5 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 6
The amount of the AS resin is out of the range of the present invention. Table 3 shows the results
Show. Although the drawdown resistance was extremely good, it was not shown in Table 3, but because the melt fracture was severe, the appearance of the molded product was insufficient even in high transfer blow molding.

[0036]

[Table 1]

[0037]

[Table 2]

[0038]

[Table 3]

[0039]

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

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view of a mold used for high transfer blow molding of the present invention.

[Explanation of symbols]

 1a, 1b Metal body having a molding surface 2a, 2b Heat insulator 3 Mold 3a, 3b Mold body 4a, 4b Space 5a, 5b Supply pipe for steam or cooling water 6a, 6b Discharge pipe for steam or cooling water

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

Claims (1)

[Claims] 1. A composition comprising (A) at least one selected from the following groups (B) to (D) with respect to 100 parts by weight of a rubber-reinforced styrene resin, Is a rubber-reinforced styrene-based resin composition for high transfer blow molding, which is blow-molded at a temperature not lower than the Vicat softening temperature of the 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 500,000 or more (D) Polymer having a (meth) acrylic ester having a weight average molecular weight of 500,000 or more as a main component .1 to 20 parts by weight