JP4876855B2 - Extruded hollow molded article and method for producing the same - Google Patents

Description

  The present invention is an extrusion hollow molding comprising a polyphenylene sulfide resin composition layer excellent in hot water resistance, antifreeze resistance, chemical resistance, heat resistance, wear resistance, gas permeation resistance, creep and surface smoothness, and moldability. Related to goods.

  Polyphenylene sulfide resin (hereinafter abbreviated as PPS resin) is excellent in heat resistance, hot water resistance, chemical resistance, flame retardancy and electrical properties, and is in demand for applications such as electricity, electronic parts, and automotive parts. It is growing. Recently, hollow molding materials that take advantage of the characteristics of the PPS resin have been proposed in Patent Documents 1 to 3 and the like.

Since the hollow molded body is often required to be flexible, the PPS resin is modified with an elastomeric material that is excellent in flexibility. On the other hand, the fitting and fixing parts of the hollow molded body are required to have creep resistance. Therefore, there has been a demand for a product having excellent flexibility and creep resistance.
Japanese Patent Laid-Open No. 10-182970 Japanese Patent Laid-Open No. 10-180911 JP 10-138372 A

  The present invention has been achieved as a result of studying improvement of the problems of the above-described PPS resin for extrusion molding, and the object thereof is to have both creep resistance and flexibility and heat resistance. Providing extruded hollow molded articles with excellent water resistance, chemical resistance, gas permeation resistance, abrasion resistance, heat resistance, chemical resistance such as zinc chloride, calcium chloride, amine resistance, excellent moldability and appearance Is.

That is, the present invention
1. At least one layer is an extruded hollow molded article made of (a) a polyphenylene sulfide resin composition, and (a) the polyphenylene sulfide resin composition constituting the layer is (a1) epoxy group based on 100 parts by weight of the PPS resin. An extruded hollow molded article comprising 3 to 50 parts by weight of the containing α-olefin copolymer, and (a3) 5 to 80 parts by weight of a crosslinked elastomer resin composition,
2. The extruded hollow molded article according to 1, wherein the extruded hollow molded article is a tube,
3. The extruded hollow molded product according to 1 or 2, wherein the extruded hollow molded product is a multilayer tube having a layer made of (b) a polyamide resin composition,
4). Between (a) a layer made of a polyphenylene sulfide resin composition and (b) a layer made of a polyamide resin composition, (c1) 50 to 300 parts by weight of polyamide resin (c3) with respect to 100 parts by weight of polyphenylene sulfide resin, (c3 ) 3 to 200 parts by weight of a thermoplastic resin having at least one functional group selected from an epoxy group, an acid anhydride group, a carboxyl group, a salt thereof, and a carboxylic acid ester; and (c4) an epoxy group, an acid anhydride group, 3. An extruded hollow molded article according to 3, wherein there is an adhesive layer comprising a resin composition formed by blending 0 to 200 parts by weight of an elastomer that does not contain any of a carboxyl group, a salt thereof, and a carboxylic acid ester,
5. The extruded hollow molded article according to any one of 1 to 4, wherein the extruded hollow molded article is an automobile fuel tube or an automobile coolant pipe,
6). At least one layer contains (a1) 3 to 50 parts by weight of an epoxy group-containing α-olefin copolymer and (a4) 5 to 80 parts by weight of an uncrosslinked olefin elastomer to 100 parts by weight of PPS resin. (A) A method for producing an extruded hollow molded product, comprising: forming an extruded hollow molded product which is a layer comprising a polyphenylene sulfide resin composition, and then crosslinking the electron beam; (A1) 100 parts by weight of polyphenylene sulfide resin is blended with (a2) 3 to 50 parts by weight of an epoxy group-containing α-olefin copolymer, and (a4) 5 to 80 parts by weight of an uncrosslinked olefin elastomer. At least one layer is (a) a method for producing an extruded hollow molded article comprising a polyphenylene sulfide resin composition, wherein the pellet comprising the polyphenylene sulfide resin composition is subjected to electron beam crosslinking and then extrusion molding.

  The PPS hollow molded article of the present invention has excellent surface appearance, heat resistance, flexibility, low temperature impact resistance, gas barrier resistance, chemical resistance such as zinc chloride and calcium chloride, moldability, economy, etc. Especially for use in heat medium circulation pipes such as automotive fuel lines and cooling pipes, snow melting or heating heating systems that are used in high temperature conditions or for many years in direct contact with water or aqueous solution, fuel oil Can be used beneficially.

The constituent components and structure of the polyphenylene hollow molded article of the present invention will be specifically described below.

  The (a1) PPS resin used in the present invention is a polymer containing 70 mol% or more, preferably 90 mol% or more of a repeating unit represented by the following structural formula. Is unfavorable because of damage.

The PPS resin is generally a polymer having a relatively low molecular weight obtained by a production method represented by Japanese Patent Publication No. 45-3368 and an essentially linear product obtained by a production method represented by Japanese Patent Publication No. 52-12240. In the polymer obtained by the method described in the above Japanese Patent Publication No. 45-3368, the polymer is heated in an oxygen atmosphere after polymerization, or a peroxide or the like. It is also possible to increase the polymerization by adding the above crosslinking agent and heating.
In the present invention, it is possible to use a PPS resin obtained by any method, but an essentially linear and relatively high molecular weight polymer is preferably used.

  Moreover, PPS resin can also comprise less than 30 mol% of the repeating units with repeating units having the following structural formula.

  The (a1) PPS resin used in the present invention is preferably one that has been subjected to deionization treatment by an acid aqueous solution washing treatment or an organic solvent washing treatment after being produced through the above steps.

  The above acid aqueous solution cleaning treatment is performed as follows.

  That is, the acid used in the acid aqueous solution cleaning treatment of the PPS resin in the present invention is not particularly limited as long as it does not have an action of decomposing the PPS resin, and acetic acid, hydrochloric acid, sulfuric acid, phosphoric acid, silicic acid, carbonic acid and propyl. Acids and the like can be mentioned, among which acetic acid and hydrochloric acid can be more preferably used, but those that decompose and deteriorate the PPS resin such as nitric acid are not preferable.

  The acid aqueous solution cleaning method includes a method of immersing a PPS resin in an acid aqueous solution, and can be appropriately stirred or heated as required. For example, when acetic acid is used, a sufficient effect can be obtained by immersing the PPS resin powder in a pH 4 aqueous solution heated to 80 to 90 ° C. and stirring for 30 minutes. The acid-treated PPS resin needs to be washed several times with water or warm water in order to physically remove the remaining acid or salt.

  The water used for washing is preferably distilled water or deionized water in the sense that it does not impair the advantageous scientific modification effect of the PPS resin by acid treatment.

  Moreover, when performing a hot water washing process, it is as follows.

  That is, in the hot water treatment of the PPS resin used in the present invention, it is important that the temperature of the hot water is 100 ° C or higher, more preferably 120 ° C or higher, further preferably 150 ° C or higher, particularly preferably 170 ° C or higher. If it is less than 100 ° C., the preferable scientific modification effect of the PPS resin is small, which is not preferable.

  It is preferable that the water used in order to develop a preferable scientific modification effect of the PPS resin by the hot water washing treatment of the present invention is distilled water or deionized water. The operation of the hot water treatment is usually performed by charging a predetermined amount of PPS resin and heating and stirring in a pressure vessel. The ratio of the PPS resin to water is preferably higher, but usually a bath ratio of 200 g or less of PPS resin is selected for 1 liter of water.

  In addition, since the decomposition of the end groups is not preferable in the hot water treatment atmosphere, it is preferable to use an inert atmosphere in order to avoid this. Furthermore, it is preferable to wash the PPS resin after this hot water treatment operation several times with warm water in order to physically remove the remaining components.

  Further, in the case of the organic solvent cleaning treatment, it is as follows.

  That is, the organic solvent used for washing the PPS resin in the present invention is not particularly limited as long as it does not have an action of decomposing the PPS resin. For example, N-methylpyrrolidone, dimethylformamide, dimethylacedamide, 1, Nitrogen-containing polar solvents such as 3-dimethylimidazolidinone, hexamethylphosphoramide, and piverazinone, sulfoxides such as dimethyl sulfoxide, dimethyl sulfone, and sulfolane, sulfone solvents, and ketone solvents such as acetone, methyl ethyl ketone, diethyl ketone, and acetophenone , Ether solvents such as dimethyl ether, dipropyl ether, dioxane, tetrahydrofuran, chloroform, methylene chloride, trichloroethylene, ethylene dichloride, perchlorethylene, monochloroethane, dichloroethane Halogen solvents such as tetrachloroethane, perchloroethane, chlorobenzene, alcohols such as methanol, ethanol, propanol, butanol, pentanol, ethylene glycol, propylene glycol, phenol, cresol, polyethylene glycol, polypropylene glycol, phenol solvents And aromatic hydrocarbon solvents such as benzene, toluene and xylene. Among these organic solvents, use of N-methylpyrrolidone acetone, dimethylformamide, chloroform and the like is particularly preferable. In addition, these organic solvents are used in one or a mixture of two or more.

  As a cleaning method using an organic solvent, there is a method of immersing a PPS resin in an organic solvent, and it is possible to appropriately stir or heat as necessary.

  There is no restriction | limiting in particular about the washing | cleaning temperature at the time of wash | cleaning PPS resin with an organic solvent, Arbitrary temperature of about normal temperature-about 300 degreeC can be selected. Here, the higher the cleaning temperature, the higher the cleaning efficiency tends to be. However, a sufficient effect is usually obtained at a cleaning temperature of room temperature to 150 ° C.

  It is also possible to wash under pressure at a temperature above the boiling point of the organic solvent in a pressure vessel. There is no particular limitation on the cleaning time. Although depending on the washing conditions, in the case of batch type washing, a sufficient effect is usually obtained by washing for 5 minutes or more. It is also possible to wash in a continuous manner.

  Although it is sufficient to wash the PPS resin produced by the polymerization with an organic solvent, it is preferable to combine it with water washing or warm water washing in order to further exhibit the effects of the present invention. Further, when a high-boiling water-soluble organic solvent such as N-methylpyrrolidone is used, it is preferable that the remaining organic solvent can be easily removed by washing with water or warm water after washing with the organic solvent. The water used for these washings is preferably distilled water or deionized water.

  (A1) The melt viscosity of the PPS resin used in the present invention is not particularly limited, and (a2) at least one functional group selected from (a2) an epoxy group, an acid anhydride group, a carboxyl group and a salt thereof, and a carboxylic acid ester is added. Any melt viscosity can be used as long as it can be kneaded with 3 to 80 parts by weight of the thermoplastic resin (a3) crosslinked elastomer. Usually, the melt viscosity at 320 ° C. and a shear rate of 10 sec-1 is used. 100 to 10,000 poises are used.

  The (a2) epoxy group-containing α-olefin copolymer used in the present invention has an α-olefin of 50.0 to 99.5 wt% and an α, β-unsaturated glycidyl ester of 0.5 to 50.0 wt%. (A1) 3.0 to 50 parts by weight is preferable with respect to 100 parts by weight of PPS. If the amount is less than 3.0 parts by weight, the dispersion of the crosslinked elastomer is insufficient and the impact strength is inferior. If the amount exceeds 50 parts by weight, a gel is formed during melt kneading with the PPS resin, and the extrusion stability, moldability, and mechanical strength are increased. , Because it adversely affects heat resistance and the like.

  The (a2) epoxy group-containing α-olefin copolymer comprises at least one thermoplastic resin having at least one functional group selected from an acid anhydride group, a carboxyl group and a salt thereof, and a carboxylic acid ester. May be.

The (a3) crosslinked elastomer resin used in the present invention comprises 10 to 40% by weight of a non-crosslinked thermoplastic resin and 60 to 90% by weight of a crosslinked rubber, and has a sea-island structure in which the non-crosslinked thermoplastic resin is a matrix and the crosslinked rubber is a domain. Yes. More preferably, (b-1) 15 to 30% by weight of a non-crosslinked thermoplastic resin and (b-2) 70 to 85% by weight of a crosslinked rubber. (B-2) The degree of cross-linking of the cross-linked rubber is such that the amount calculated by the following formula is 50% or more from the amount of unmelted residue after freeze-pulverizing the dynamically cross-linked elastomeric resin and extraction with toluene at 80 ° C. for 8 hours, Is 70% or more.
Degree of crosslinking = (extraction residue amount−amount of thermoplastic resin not crosslinked) / dynamic amount of crosslinked elastomeric resin × 100
Examples of the thermoplastic resin that does not crosslink include polypropylene, polyester, polyamide, PPS, and the like. In particular, polypropylene is preferable in terms of processability and compatibility with rubber.

  The rubber component of the crosslinked rubber is a chemically synthesized synthetic rubber and can be used as long as it can be crosslinked. For example, styrene butadiene rubber, acrylonitrile butadiene rubber, butadiene rubber, isoprene rubber, chloroprene rubber, ethylene propylene rubber , Ethylene butene rubber, ethylene octene rubber, and acrylic rubber. These may be used alone or in combination of two or more. In particular, ethylene propylene rubber, ethylene butene rubber, and ethylene octene rubber are preferable from the viewpoint of compatibility with the epoxy group-containing α-olefin copolymer.

  The method of crosslinking these synthetic rubbers is a method in which a thermoplastic resin and a synthetic rubber that are not crosslinked by a twin screw extruder are put into an extruder hopper together with a crosslinking agent and an initiator, and are dynamically crosslinked in the extruder, or are not crosslinked. Thermoplastic resin and synthetic rubber may be melt-kneaded with an extruder and pelletized, and then irradiated with an electron beam for crosslinking.

  As a method for producing the resin composition used for the Oshida medical hollow molded article of the present invention, it can be produced by a known single screw extruder or twin screw extruder. From the viewpoint of dispersion of the crosslinked elastomer, a twin screw extruder is used. preferable. As a method of dispersing the cross-linked elastomer in the PPS, a method of blending and extruding a PPS resin, a pre-cross-linked cross-linked elastomer and a compatibilizing material, or after blending and extruding a PPS resin, an uncross-linked elastomer and a compatibilizing material, There is a method of cross-linking pellets with an electron beam. The method of blending and extruding the PPS resin, the cross-linked TPE cross-linked in advance and the compatibilizing material can be produced only with ordinary compound equipment, and is economically advantageous. On the other hand, after blending and extruding a PPS resin, uncrosslinked TPE and a compatibilizing material, the resin composition obtained by crosslinking the pellets with an electron beam can control the dispersion diameter of the crosslinked rubber to be smaller, and has excellent toughness. A composition is obtained.

  Examples of the method for producing the polyphenylene sulfide hollow molded body of the present invention include an extrusion molding method and a blow molding method, and any known molding method can be used. The tube forming method is particularly preferable, and will be specifically described below.

  The tube forming machine includes an extruder for melting and kneading pellets, a tube die for extruding molten resin into a cylindrical shape, a sizing die for determining a tube diameter, a vacuum / cooling tank, and a take-up machine.

  Supply the resin composition for the above polyphenylene sulfide hollow molded body to an extruder, pressure supply the molten resin into the die to form an annular flow, and then extrude it out of the die and dimension it with a sizing die and vacuum chamber Is cooled and solidified in a cooling tank, and a tubular product is obtained by a take-up machine.

  Further, as a method other than the above, (a1) 3 to 50 parts by weight of an epoxy group-containing α-olefin copolymer and (a4) 5 to 80 parts by weight of an uncrosslinked olefin elastomer with respect to 100 parts by weight of the PPS resin. The rubber component may be crosslinked by supplying a thermoplastic resin composition comprising the above to a tube molding machine and subjecting the obtained tube molded product to electron beam crosslinking. The method of electron beam crosslinking of a tube made of uncrosslinked rubber can also be used to crosslink only a necessary part of the product, and is useful for enhancing the product function.

  The size of the extruder for molding the polyphenylene sulfide resin of the present invention is not particularly limited, but preferably the diameter is 30 mm to 50 mm and the L / D is 20 to 36. If the diameter is less than 30 mm, the discharge amount is small and the residence time in the extruder becomes long, and the resin is deteriorated, which is not preferable. On the other hand, when the extruder is 50 mm or more, the discharge amount is too large, the tube forming speed is too high, and the tube strength decreases, which is not preferable. When L / D is 20 or less, the discharge amount is not stable, and when L / D is 36 or more, the residence time in the extruder becomes long and the resin deteriorates, which is not preferable.

The screw used in the present extruder preferably has a full flight type compression ratio of 2.5 to 3.5, and the ratio of the number of flights of each part to the number of flights of the entire screw is the metering part: compression part: conveying part = 0. 3-0.4: 0.1-0.3: 0.3-0.6 are preferable. If the compression ratio is less than 2.5, unmelted pellets may be discharged, and if the compression ratio is 3.5 or more, the screw load increases, which is not preferable. If the ratio of the number of flights in the measuring section is less than 0.3, the discharge amount is not stable and the thickness of the tube fluctuates. If the ratio of the number of flights in the transport section is less than 0.3, the plasticizing of the pellet is insufficient and the screw load is reduced. There is a risk that the screw will stop and become undesired.

The molding temperature of the polyphenylene sulfide resin of the present invention is preferably 290 ° C. to 330 ° C., and is preferably molded with a discharge amount so that the residence time in the molding machine is within 10 minutes. If the molding temperature is less than 290 ° C, the plasticization of PPS becomes insufficient, and if it is 330 ° C or more, the elastomer is thermally deteriorated.
Further, if the residence time in the extruder is 10 minutes or longer, the elastomer deteriorates and projections are formed on the surface of the molded product, resulting in an unfavorable appearance.

  The extruded hollow molded article of the present invention may be a single layer made of a polyphenylene sulfide resin composition, but may have a multilayer structure with other thermoplastic resins. Molding is a common co-extrusion method, for example, in the case of a two-layer tube, the PPS resin composition and other thermoplastic resin are separately supplied to two extruders, and these two types of molten resins are extruded separately. After each flow is supplied into a common die to form an annular flow, they are merged in the die, one is formed in the inner layer, the other is formed in the outer layer, and then co-extruded outside the die. A two-layer tube is obtained by a known tube forming method.

  In the case of a three-layer tubular body, three layers can be formed by the above method using three extruders, or two types and three layers of tubes can be obtained using two extruders. Furthermore, it is also possible to obtain a multilayer tube having three or more layers by using a plurality of extruders.

  The above-described method for producing a multilayer molded article is merely an example and is not limited thereto.

  The thermoplastic resin composition other than the PPS resin composition for forming a multilayer structure in the extruded hollow molded article according to the present invention may be any one as long as it can be melt-molded. For example, polyethylene, polypropylene, polystyrene, acrylonitrile / styrene (SAN) , ABS, methyl methacrylate (MMA) vinyl chloride, polyamide, polyacetal, polybutylene terephthalate, polyethylene terephthalate, polycarbonate, modified polyphenylene ether, LCP, and the like, especially from the viewpoint of moldability and chemical resistance Resin compositions are useful.

  The polyamide resin (b) preferably used in the present invention is polycaproamide (nylon 6), polyhexamethylene adipamide (nylon 66), polytetramethylene adipamide (nylon 46), polyhexamethylene sebacamide ( Nylon 610), polyhexamylene dodecamide (nylon 612), polydodecanamide (nylon 12), polyundecanamide (nylon 11), polyhexamethylene terephthalamide (nylon 6T), polyxylylene adipamide (nylon XD6) ) And mixtures or copolymers thereof. The degree of polymerization of the polyamide resin is not particularly limited, and the relative viscosity measured at 25 ° C. in a 98% concentrated sulfuric acid solution is in the range of 1.5 to 7.0, particularly in the range of 2.0 to 6.5. Those are preferred. Among these, nylon 6, nylon 66, nylon 11, nylon 12 and copolymers thereof are preferable in terms of heat resistance, moldability, and economy.

In a preferred embodiment of the extruded hollow molded article of the present invention, the structure of (a) the layer composed of the PPS resin composition and (b) the layer composed of the polyamide resin composition can be freely selected because various required properties differ depending on the application. For example, in the case of two layers, one may be either the inner layer or the outer layer of the molded product. In the case of three layers, (c) an adhesive property is exhibited in order to bond these layers between (a) a layer made of a PPS resin composition and (b) a layer made of a polyamide resin composition as an intermediate layer. It is preferable to have a layer made of a thermoplastic resin composition.
(C) The thermoplastic resin composition constituting the adhesive layer is (c1) 100 parts by weight of polyphenylene sulfide resin, (c2) 50 to 300 parts by weight of polyamide resin, (c3) epoxy group, acid anhydride group, carboxyl group and 3 to 200 parts by weight of a thermoplastic resin having at least one functional group selected from salts and carboxylic acid esters thereof, (c4) an epoxy group, an acid anhydride group, a carboxyl group and salts thereof, and an elastomer containing no carboxylic acid ester A thermoplastic resin composition obtained by blending 0 to 200 parts by weight is preferable.
Here, it is preferable from the viewpoint of adhesion that the (c2) polyamide resin is of the same kind or compatibility with the polyamide resin constituting the (b) polyamide resin layer.
(C3) As the thermoplastic resin having at least one functional group selected from an epoxy group, an acid anhydride group, a carboxyl group and a salt thereof, and a carboxylic acid ester, an olefin copolymer having such a functional group, a fluorine-based copolymer A copolymer etc. can be illustrated.
The epoxy group-containing compound is an olefin copolymer having an epoxy group in the side chain or main chain, and does not contain a normal epoxy group. As an epoxy group-containing olefin copolymer, the double bond of an olefin copolymer having a glycidyl group such as glycidyl ester, glycidyl ether or glycidyl amine in the side chain or a double bond-containing olefin copolymer is epoxy-oxidized. Things. In the present invention, among these epoxy group-containing olefin copolymers, a copolymer comprising an α-olefin and an α, β-unsaturated glycidyl ester is preferably used. Examples of the α-olefin herein include ethylene, propylene, and butene-1. Further, the glycidyl ester of α, β-unsaturated acid is a compound represented by the following general formula, and specifically includes glycidyl acrylate, glycidyl methacrylate and glycidyl ethacrylate, among which glycidyl methacrylate is particularly preferred. Is preferably used.

(However, R in the formula represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.)
The (c2) epoxy group-containing compound may be any of random, block, and graft copolymers of the above α-olefin and α, β-unsaturated acid glycidyl.
The epoxy group content in the (c2) epoxy group-containing compound of the present invention is preferably 3 to 200% by weight, more preferably 10 to 150% by weight. If it is less than 3% by weight, the intended effect is insufficient, and if it exceeds 200% by weight, a gel is formed during melt-kneading with the PPS resin, which adversely affects extrusion stability, moldability, mechanical strength, etc., which is not preferable. .

  (C2) Epoxy group-containing compounds may be copolymerized with other olefinic monomers such as methyl acrylate, methyl methacrylate, acrylonitrile, styrene, vinyl acetate and vinyl ether as long as the effects of the present invention are not impaired. good.

  Examples of the polyolefin polymer having a carboxyl group and a salt thereof, a carboxylic acid ester group, and an acid anhydride group preferably used in the present invention include polyethylene, polypropylene, polystyrene, ethylene-propylene copolymer, and ethylene-butene copolymer. Polymers, polybutenes, ethylene-propylene-diene copolymers, styrene-butadiene copolymers, polybutadienes, butadiene-acrylonitrile copolymers, polyisoprenes, butene-isoprene copolymers, and styrene-ethylene-butadiene-styrene copolymers Polyolefin resins such as maleic anhydride, succinic anhydride, fumaric anhydride, acrylic acid, methacrylic acid, vinyl acetate and its salts such as Na, Zn, K, Ca, Mg, methyl acrylate, methacrylic acid Methyl, acrylic acid ethyl , Ethyl methacrylate, propyl acrylate, propyl methacrylate, butyl acrylate, butyl methacrylate, and the like copolymerized olefin copolymer. The copolymerization mode of such an olefin polymer is not particularly limited, and any copolymer mode such as a random copolymer, a graft copolymer, or a block copolymer may be used.

  Here, (c4) as an elastomer not containing an epoxy group, an acid anhydride group, a carboxyl group and a salt thereof, or a carboxylic ester, for example, an ethylene-propylene copolymer, an ethylene-butene copolymer, a polybutene, an ethylene-propylene-diene Copolymers, polyolefin elastomers such as ethylene-vinyl acetate copolymer, styrene-butadiene copolymers, polybutadiene, butadiene-acrylonitrile copolymers, diene elastomers such as polyisoprene butene-isoprene copolymers and hydrogenation thereof , Acrylics such as ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-isopropyl acrylate copolymer, ethylene-methyl methacrylate copolymer, ethylene-ethyl methacrylate copolymer Such as elastomer, and the like. Of these, ethylene-propylene copolymer, ethylene-butene copolymer, and ethylene-propylene-diene copolymer are particularly preferable. Such (c2) epoxy group, acid anhydride group, carboxyl group and salt thereof, and an elastomer containing no carboxylic acid ester may be used in combination of two or more. In the present invention, in order to obtain strong adhesion strength between the layers of the PPS resin composition and the polyamide resin, it is preferable to set the molding temperatures of both resins as close as possible to the same temperature. If the temperature of the thermoplastic resin other than PPS is extremely low with respect to the melting temperature of the PPS resin composition, the surface of the PPS resin composition tends to solidify during coextrusion, and the adhesion strength decreases. A preferable molding temperature is PPS resin composition 290 to 330 ° C., a polyamide resin has a melting point +10 to 80 ° C., more preferably a PPS resin composition 290 to 310 ° C., and a polyamide resin has a melting point +20 to 60 ° C.

In the present invention, the fibrous and / or non-fibrous filler is not an essential component, but can be blended within a range not exceeding 100 parts by weight with respect to 100 parts by weight of the polyphenylene sulfide resin as necessary. . In general, by blending in the range of 10 to 90 parts by weight, it is possible to improve strength, rigidity, heat resistance and dimensional stability.
Such fibrous and / or non-fibrous fillers include glass fibers, alumina fibers, silicon carbide fibers, ceramic fibers, asbestos fibers, stone fiber, metal fibers and carbon fibers, wollastonite, zeolite , Silicates such as sericanite, kaolin, mica, clay, pyroferrite, bentonite, asbestos, talc, alumina silicate, metal compounds such as alumina, silicon oxide, magnesium oxide, zirconium oxide, titanium oxide, calcium carbonate, magnesium carbonate, dolomite Carbonates such as calcium sulfate, sulfate such as barium sulfate, glass. Non-fibrous fillers such as beads, boron nitride, silicon carbide and silica may be mentioned, and these may be hollow. Two or more kinds of these fillers can be used in combination, and can be used after pretreatment with a coupling agent such as silane or titanium if necessary.
In addition, the (a) PPS resin used in the present invention includes a crystal nucleating agent, a mold release agent, an antioxidant, a heat stabilizer, a lubricant, an ultraviolet light inhibitor, a colorant, and a difficult material within a range not impairing the effects of the present invention. Conventional additives such as flame retardants and small amounts of other polymers can be added.

  The polyphenylene sulfide extruded hollow molded article of the present invention thus obtained is particularly excellent in flexibility and creep resistance, and further has hot water resistance, antifreeze resistance, chemical resistance, gasoline resistance, alcohol resistance, heat resistance, molding. Because of its excellent properties, appearance and interlayer adhesion, it can be used as blow molded products such as bottles, tanks and ducts, and as extrusion molded products such as sheets, tubes, pipes and films. It is particularly effective for automobile fuel tubes and cooling pipes.

  Hereinafter, the present invention will be described in detail with reference to examples.

  The creep properties, flexibility, gasoline resistance, and interlayer adhesion strength of the polyphenylene sulfide hollow molded bodies described in the following Examples and Comparative Examples were measured by the following methods.

  (A) PPS resin composition, (b) Polyamide resin is melt-kneaded inside the extruder and supplied to the co-extrusion die by the tube forming method described above, and melt-bonded in multiple layers at the joint in the co-extrusion die Then, it is coextruded as a tubular body or a parison from the die face at the tip. This was cooled and solidified by a sizing device to form a tube having an outer diameter of 8 mm and an inner diameter of 6 mm. Evaluation of the obtained tube followed the following method.

1. Creep characteristics A metal rod (FIG. 1) having an outer diameter of 8 mm and an inner diameter of 6 mm obtained by the above method is inserted into a tube and the pulling force after heat treatment at 120 ° C. × 200 hr is calculated by the following formula and the retention rate is 80%. The above was rated as “excellent”, 50 to less than 80 as “good” and less than 50 as “good”.

Retention rate (%) = initial pulling force (MPa) / pulling force after heat treatment (MPa) × 100
2. Flexibility A tube having an outer diameter of ¢ 8 mm and an inner diameter of 6 mm obtained by the above method was wound around a cylinder, and the radius (mm) of the cylinder at which the tube diameter was 50% of the initial value was defined as flexibility.

3. Gasoline resistance (a) The PPS resin composition was put into the hopper of an L / D = 20 30 mm extruder for the inner layer whose temperature was adjusted to 310 ° C., (c) For the intermediate layer whose adhesive resin was temperature-controlled to 310 ° C. L / D = 20 30 mm extruder hopper, (b) Polyamide resin is supplied to the hopper of L / D = 25 40 mm extruder whose temperature is adjusted to the melting point + 20-60 ° C. The molten parison was cooled and solidified with an extrusion sizing device to obtain a three-layer tube having an outer diameter of 8 mm and an inner diameter of 6 mm. The thickness of each layer was 0.6 mm for the outer layer, 0.2 mm for the intermediate layer, and 0.2 mm for the inner layer.
The obtained tube was cut into a length of 30 cm, Fuel C + E10 (toluene / isooctane / ethanol = 45/45/10 vol%) was sealed, and both ends of the tube were sealed with metal stoppers. The tube was placed in an explosion-proof oven at 60 ° C. and the weight loss was measured and plotted. The weight reduction per unit time (W) when the weight reduction rate showed linearity was divided by the inner surface area (S) of the tube to obtain gasoline resistance.

Gasoline resistance (g / m ² · day) = W (g / hr) / S (m ² ) × 24 (hr)
4). Interlaminar adhesive strength A multilayer tube having an outer diameter of φ8 mm and an inner diameter of φ6 mm obtained by the above method was cut into a length of 150 mm and further divided into two in the longitudinal direction to obtain strip-shaped test pieces. The interlayer is peeled off from one end of the obtained test piece and forcedly peeled up to a position of 50 mm from the end. The peeled layer was pulled up and down at a speed of 10 mm / min with a tensile tester, and the value obtained by dividing the average load (MPa) between the movement amount of the crosshead between 20 mm and the width (cm) of the test piece was the interlayer adhesive strength. (MPa / cm).

Reference example 1 (polymerization of PPS)
Sodium sulfide 3.20 kg (25 mol, containing 40% crystal water), sodium hydroxide 4 g, sodium acetate trihydrate 1.36 kg (about 10 mol) and N-methyl-2-pyrrolidone (hereinafter abbreviated as NMP) in an autoclave 7.9 kg was charged, the temperature was gradually raised to 205 ° C. with stirring, and about 1.5 liters of distilled water containing 1.36 kg of water was removed.
To the residual mixture, 3.75 kg (25.5 mol) of 1,4-dichlorobenzene and 2 kg of NMP were added, sealed under an inert gas such as nitrogen gas, and heated at 265 ° C. for 3 hours. The reaction product was washed 5 times with warm water at 70 ° C. and dried under reduced pressure at 80 ° C. for 24 hours to obtain a powdery PPS resin (P-1) having a melt viscosity of about 1500 poise (320 ° C., shear rate 10 sec-1). 2 kg was obtained. About 2 kg of the obtained PPS resin powder was put into 20 liters of NMP heated to 100 ° C., stirred for about 30 minutes, filtered, and then washed with ion-exchanged water at about 90 ° C. This was dried under reduced pressure at 120 ° C. for 24 hours to obtain a PPS resin (a1). Similar operations were repeated and used in the examples described below.

Reference Example 2 ((a) Production of polyphenylene resin composition)
The blended materials shown in Table 1 were dry blended at the ratio shown in Table 1, premixed for 2 minutes with a tumbler, melt-kneaded with a twin screw extruder set at a cylinder temperature of 300 ° C., pelletized with a strand cutter, 120 PPS1-5 was obtained by drying overnight at ° C. The MFR retention rate of the obtained pellet was as shown in Table 1.
For PPS-6, PPS-4 pellets were spread on a 20 cm x 30 cm x 5 cm tray using an 800 kV electron beam irradiation device manufactured by NHV Corporation, and the pellets were cross-linked with 60 kGy irradiation twice in air. Got.

Reference Example 3 ((c) Production of adhesive resin)
After dry blending (a1) PPS resin, (c1) functional group-containing thermoplastic resin, uncrosslinked elastomer and antioxidant of the blending materials shown in Table 2 in the proportions shown in Table 2, and premixing them for 2 minutes with a tumbler The mixture was melt kneaded with a twin screw extruder set at a cylinder temperature of 300 ° C., pelletized with a strand cutter, and dried at 120 ° C. overnight. Polyamide resin and (c2) functional group-containing thermoplastic resin were dry blended in the ratio shown in Table 2 to the obtained pellets, premixed for 2 minutes with a tumbler, and then in a twin screw extruder set at a cylinder temperature of 300 ° C. It melt-kneaded, pelletized with the strand cutter, and dried at 120 degreeC overnight, and AD1,2 was obtained.

Example 1
L / D = 20 30 mm extruder for inner layer with PPS-1 temperature adjusted to 310 ° C., L / D = 20 30 mm extruder for intermediate layer with AD-1 temperature adjusted to 310 ° C. The AESNOTL was supplied to the hopper of a 40 mm extruder with L / D = 25 whose temperature was adjusted to 260 ° C., three layers of molten parison were extruded through a multilayer die, cooled and solidified with a sizing device, and an outer diameter of 8 mm and an inner diameter of 6 mm A three-layer tube was obtained. The thickness of each layer of the obtained tube was 0.6 mm for the outer layer, 0.2 mm for the intermediate layer, and 0.2 mm for the inner layer.

  The obtained multilayer tube was excellent in creep characteristics, fuel barrier properties, and adhesiveness.

Examples 2-4, Comparative Examples 1-2
Example 1 was repeated except that the PPS resin composition was as shown in Table 3.

  The tube using the crosslinked TPE was excellent in creep characteristics as compared with Comparative Examples 1 and 2.

Example 5
L / D = 20 30 mm extruder for inner layer with PPS-1 temperature adjusted to 310 ° C., L / D = 20 30 mm extruder for intermediate layer with AD-1 temperature adjusted to 310 ° C. The molten parison of two layers was extruded through a multilayer die and cooled and solidified with a sizing device to obtain a two-layer tube having an outer diameter of φ8 mm and an inner diameter of φ6 mm. The obtained multilayer tube was excellent in creep properties, flexibility, fuel barrier properties, and adhesiveness, regardless of the nylon layer.

Comparative Example 3
Example 4 was the same as Example 4 except that PPS shown in Table 3 was used. This tube was inferior in creep property as compared with Example 4.

Example 6
L / D = 20 30 mm extruder for inner layer with PPS-4 temperature adjusted to 310 ° C., L / D = 20 30 mm extruder for intermediate layer with AD-1 temperature adjusted to 310 ° C. The AESNOTL was supplied to the hopper of a 40 mm extruder with L / D = 25 whose temperature was adjusted to 260 ° C., three layers of molten parison were extruded through a multilayer die, cooled and solidified with a sizing device, and an outer diameter of 8 mm and an inner diameter of 6 mm A three-layer tube was obtained. The thickness of each layer of the obtained tube was 0.6 mm for the outer layer, 0.2 mm for the intermediate layer, and 0.2 mm for the inner layer. The obtained tube was irradiated twice with 60 kGy in an oxygen atmosphere using an 800 kV electron beam irradiation apparatus manufactured by NHV Corporation to obtain a crosslinked tube.
The obtained tube was excellent in creep characteristics as compared with Comparative Example 1.

Example 7
Example 1 was repeated except that PPS-6 used for the inner layer was changed to PPS-6. Like the obtained pellet and Example 1, the creep characteristics were better than those of Comparative Example 1.

It is a figure which shows the outline | summary of the creep characteristic test in an Example.

Claims (7)

  At least one layer is an extruded hollow molded article made of (a) a polyphenylene sulfide resin composition, and (a) the polyphenylene sulfide resin composition constituting the layer is (a1) epoxy group based on 100 parts by weight of the PPS resin. An extruded hollow molded article comprising 3 to 50 parts by weight of the containing α-olefin copolymer and 5 to 80 parts by weight of (a3) a crosslinked elastomer resin composition. The extruded hollow molded article according to claim 1, wherein the extruded hollow molded article is a tube. The extruded hollow molded article according to claim 1 or 2, wherein the extruded hollow molded article is a multilayer tube having a layer made of (b) a polyamide resin composition. Between (a) a layer made of a polyphenylene sulfide resin composition and (b) a layer made of a polyamide resin composition, (c1) 50 to 300 parts by weight of polyamide resin (c3) with respect to 100 parts by weight of polyphenylene sulfide resin, (c3 ) 3 to 200 parts by weight of a thermoplastic resin having at least one functional group selected from an epoxy group, an acid anhydride group, a carboxyl group, a salt thereof, and a carboxylic acid ester; and (c4) an epoxy group, an acid anhydride group, The extruded hollow molded article according to claim 3, wherein an adhesive layer comprising a resin composition comprising 0 to 200 parts by weight of an elastomer not containing any of a carboxyl group, a salt thereof, and a carboxylic acid ester is present. The extruded hollow molded article according to any one of claims 1 to 4, wherein the extruded hollow molded article is an automobile fuel tube or an automobile coolant pipe.
At least one layer contains (a1) 3 to 50 parts by weight of an epoxy group-containing α-olefin copolymer and (a4) 5 to 80 parts by weight of an uncrosslinked olefin elastomer to 100 parts by weight of PPS resin. (A) A method for producing an extruded hollow molded product comprising forming an extruded hollow molded product which is a layer made of a polyphenylene sulfide resin composition, followed by electron beam crosslinking. (A1) 100 parts by weight of polyphenylene sulfide resin is blended with (a2) 3 to 50 parts by weight of an epoxy group-containing α-olefin copolymer, and (a4) 5 to 80 parts by weight of an uncrosslinked olefin elastomer. A method for producing an extruded hollow molded article comprising at least one layer (a) comprising a polyphenylene sulfide resin composition, wherein the pellet comprising the polyphenylene sulfide resin composition is subjected to electron beam crosslinking and then extrusion molding.

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