Piping member

Abstract

For the purpose of providing a cylindrical or tubular piping member having excellent impact resistance and high strength, a piping member 1 of the present invention is characterized by being provided with a portion 3 of which the inner surface to be in contact with liquid is formed from a resin composition containing a polyphenylene-ether-based resin and a styrene-based elastomer. The styrene-based elastomer is at least one selected from the group consisting of styrene-ethylene / propylene-styrene block copolymers, styrene-ethylene / butylene-styrene block copolymers, and styrene-butadiene-styrene copolymers. The unit amount of the styrene contained in the styrene-based elastomer is 25-65 mass% relative to the styrene-based elastomer.

Description

Piping components

[0001] The present invention relates to a piping member having a portion of its inner surface, which comes into contact with a liquid, made of a resin composition containing a polyphenylene ether resin.

[0002] Conventionally, in the manufacturing of semiconductor-related products, for example, in wet processes such as cleaning, ultrapure water purified to an extremely high degree of purity, or ultra-high purity cleaning solutions purified to an extremely high degree of purity according to the required composition, have been used.

[0003] As a resin used for piping in semiconductor cleaning solutions, fluororesins that are chemically inert and possess gas barrier properties are used. For example, Patent Document 1 discloses a double-walled fluororesin tube, which is made of two layers of fluororesin, as piping used in semiconductor manufacturing equipment. The inner layer tube is made of a fluororesin with excellent corrosion resistance and chemical resistance (for example, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), or tetrafluoroethylene-ethylene copolymer (ETFE)), and the outer layer tube is made of a fluororesin that can suppress gas permeation (for example, polyvinylidene fluoride (PVDF)). Patent Document 2 also discloses a multilayer tube for ultrapure water piping, which is made of fluororesin and comprises a first resin layer that comes into contact with ultrapure water, and a second resin layer made of a gas-impermeable resin and provided on the outer surface of the first resin layer. Furthermore, it is disclosed that a third resin layer is provided on the outer surface of the second resin layer to protect the second resin layer, and that polyethylene is used as the third resin layer.

[0004] Among the resins used as materials for semiconductor cleaning fluid piping, PVDF is used in all applications in the semiconductor field, including piping within semiconductor cleaning fluid manufacturing equipment and piping for transporting semiconductor cleaning fluid from the manufacturing equipment to the point of use, and has become the technical standard for semiconductor cleaning fluid piping.

[0005] Japanese Patent Publication No. 2006-112507 Japanese Patent Publication No. 2010-234576

[0006] The objective of the present invention is to provide a piping member that has excellent impact resistance and high strength.

[0007] The present invention is described below. 1. A piping member comprising an inner surface that comes into contact with a liquid, the portion of which is made of a resin composition, wherein the resin composition contains a polyphenylene ether resin and a styrene elastomer, the styrene elastomer is at least one selected from styrene-ethylene-propylene-styrene block copolymer, styrene-ethylene-butylene-styrene block copolymer, and styrene-butadiene-styrene copolymer, and the amount of styrene units contained in the styrene elastomer is 25 to 65% by mass relative to the styrene elastomer. 2. The piping member according to item 1, wherein the content of the styrene elastomer is 3 to 25% by mass relative to the resin composition. 3. The piping member according to item 1 or 2, wherein the melt flow rate (260°C, 10 kgf) of the resin composition is 6.0 to 25 g / 10 min. 4. The piping member according to any one of items 1 to 3, wherein the inner surface comprises a portion having a surface roughness Rz of 0.5 μm or less. 5. The piping member described in any of items 1 to 4 above is a pipe, tube, fitting, flange, or valve.

[0008] The piping member of the present invention comprises a portion made of a resin composition containing a styrene-based elastomer with a styrene unit content of 25 to 65% by mass, and therefore has excellent impact resistance and high strength. The piping member of the present invention has high tensile modulus and tensile fracture strain at both room temperature and 80°C, thus possessing resistance to external forces, and is useful, for example, in industries that utilize liquids at temperatures below 120°C through piping.

[0009] This is a schematic diagram showing an example of the cross-sectional structure of the piping member of the present invention. This is a schematic diagram showing another example of the cross-sectional structure of the piping member of the present invention.

[0010] The piping member of the present invention is, for example, a pipe, tube, fitting, flange, or valve, which is a cylindrical or tubular article having a portion (hereinafter referred to as the "first pipe portion") made of a resin composition comprising a polyphenylene ether resin and a styrene elastomer of a specific type and having a specific amount of styrene units, on the inner surface that comes into contact with the liquid.

[0011] The piping member of the present invention may consist only of a first pipe section, or it may include a first pipe section and an exterior section, a reinforcing section, etc., formed on at least a part of its outer surface.

[0012] Figures 1 and 2 are schematic diagrams illustrating the cross-sectional structure of the piping member of the present invention. The piping member 1 in Figure 1 is a multi-layered piping member comprising a first pipe section 3 and an outer covering section 5 formed on at least a part of its outer surface. The piping member 1 in Figure 2 is a piping member consisting only of the first pipe section 3. Thus, the piping member of the present invention has a structure in which the liquid flowing through it comes into contact with the inner surface of the first pipe section 3, that is, the surface where the resin composition is exposed.

[0013] The resin composition according to the present invention contains a polyphenylene ether resin and a styrene elastomer having a styrene unit content of 25 to 65% by mass, and may further contain other components (described later).

[0014] The polyphenylene ether resin according to the present invention is a resin component that can be used to manufacture resin molded articles, and preferably comprises a polyphenylene ether resin and another resin. When the polyphenylene ether resin comprises a polyphenylene ether resin and another resin, it may be a simple mixture in which the two can be easily separated, or it may be a composite in which the two are intertwined and do not easily separate. The content of the polyphenylene ether resin in the resin composition is preferably 60% or more, and more preferably 70% or more.

[0015] Polyphenylene ether resin is a resin containing at least one structural unit represented by the following general formula (1). (In the formula, R １ , R ２ , R ３ and R ４may be the same as or different from each other, and is selected from a hydrogen atom, a halogen atom, an unsubstituted or substituted hydrocarbon group, an alkoxy group, a cyano group, a phenoxy group, and a nitro group. )

[0016] In the above general formula (1), R １ , R ２ , R ３ or R ４ When it is an unsubstituted hydrocarbon group, it can be an alkyl group, a phenyl group, etc. In the above general formula (1), R １ , R ２ , R ３ or R ４ When it is a halogen atom, it may be any of Cl, Br, and I. In the above general formula (1), R １ , R ２ , R ３ or R ４ When it is an unsubstituted or substituted hydrocarbon group, the number of carbon atoms contained in the hydrocarbon group is preferably 1 to 8, more preferably 1 to 4. The unsubstituted hydrocarbon group may be either a saturated hydrocarbon group or an unsaturated hydrocarbon group. Examples of the substituted hydrocarbon group include a halogenated hydrocarbon group, a hydrocarbon group having an amino group, a hydrocarbon group having an alkoxy group, a hydrocarbon group having a cyano group, a hydrocarbon group having a phenoxy group, a hydrocarbon group having a nitro group, and the like. In the above general formula (1), R １ , R ２ , R ３ or R ４ When it is an alkoxy group, the number of carbon atoms contained in the hydrocarbon group constituting the alkoxy is preferably 1 to 8, more preferably 1 to 4.

[0017] The polyphenylene ether resin consists of only one type of structural unit represented by the general formula (1) above: poly(2,6-dimethyl-1,4-phenylene) ether, poly(2-methyl-6-ethyl-1,4-phenylene) ether, poly(2,6-diethyl-1,4-phenylene) ether, poly(2-ethyl-6-n-propyl-1,4-phenylene) ether, and poly(2,6-di-n-propyl-1,4-phenylene) ether. , poly(2-methyl-6-n-butyl-1,4-phenylene) ether, poly(2-ethyl-6-isopropyl-1,4-phenylene) ether, poly(2-methyl-6-chloroethyl-1,4-phenylene) ether, poly(2-methyl-6-hydroxyethyl-1,4-phenylene) ether, poly(2-methyl-6-chloroethyl-1,4-phenylene) ether, poly(2,6-dimethoxy-1,4-phenylene) ether Examples include homopolymers such as poly(2,6-dichloromethyl-1,4-phenylene) ether, poly(2,6-dibromomethyl-1,4-phenylene) ether, poly(2,6-diphenyl-1,4-phenylene) ether, poly(2,6-ditril-1,4-phenylene) ether, poly(26-dichloro-1,4-phenylene) ether, poly(2,6-dibenzyl-1,4-phenylene) ether, and poly(2,5-dimethyl-1,4-phenylene) ether; and copolymers such as 2,6-dimethylphenol / 2,3,6-trimethylphenol copolymer, 2,6-dimethylphenol / 2,3,6-trimethylphenol copolymer, 2,6-diethylphenol / 2,3,6-trimethylphenol copolymer, and 2,6-dipropylphenol / 2,3,6-trimethylphenol copolymer, which consist of multiple types of structural units represented by the above general formula (1).

[0018] The molecular weight of the polyphenylene ether resin is not particularly limited. The number-average molecular weight determined by gel permeation chromatography (GPC) is preferably 30,000 to 100,000, more preferably 40,000 to 60,000.

[0019] Other resins constituting the polyphenylene ether resin according to the present invention include resins containing structural units derived from aromatic vinyl compounds (hereinafter referred to as "styrene resin"), polyamides, polyolefins, polyphenylene sulfide, polyphthalamides, and resins containing structural units derived from unsaturated acid anhydrides. The other resins included may be one or two or more. The content ratio of the polyphenylene ether resin and the other resins is preferably 30 to 70% by mass and 70 to 30% by mass, respectively, when the total of both is 100% by mass, and more preferably 40 to 60% by mass and 60 to 40% by mass. In the present invention, it is preferable that the polyphenylene ether resin and the other resins constitute an alloy resin.

[0020] In the present invention, the other resin is preferably a styrene resin. The styrene resin can be at least one selected from homopolymers, copolymers, and graft polymers obtained using aromatic vinyl compounds such as styrene, α-methylstyrene, o-methylstyrene, p-methylstyrene, p-tert-butylstyrene, and 1,3-dimethylstyrene. For example, polystyrene, rubber-modified polystyrene, ABS resin, styrene-acrylonitrile copolymer, styrene-acrylonitrile-methyl methacrylate copolymer, styrene-butadiene block copolymer, and hydrogenated styrene-butadiene block copolymer can be used.

[0021] When the polyphenylene ether-based resin according to the present invention consists of a polyphenylene ether resin and a styrene resin, it is preferable that the styrene resin is a graft polymer and forms a composite (alloy resin) that intertwines with the polyphenylene ether resin.

[0022] The styrene-based elastomer according to the present invention is at least one selected from styrene-ethylene-propylene-styrene block copolymer, styrene-ethylene-butylene-styrene block copolymer, and styrene-butadiene-styrene copolymer, having a styrene unit content of 25 to 65% by mass, preferably 35 to 65% by mass, and more preferably 40 to 65% by mass. Because the resin composition according to the present invention contains such a styrene-based elastomer, the piping member including the first pipe section exhibits excellent impact resistance and high strength.

[0023] In the resin composition according to the present invention, the content ratio of polyphenylene ether resin and styrene elastomer is not particularly limited, but in order to obtain the effects of the present invention to be fully obtained, when the total amount of both is 100% by mass, the content ratio is preferably 50 to 99% by mass and 1 to 50% by mass, respectively, and more preferably 70 to 98% by mass and 2 to 30% by mass.

[0024] The resin composition according to the present invention may consist of a polyphenylene ether resin and a styrene elastomer, or, as described above, may consist of a polyphenylene ether resin, a styrene elastomer, and other components.

[0025] Other components include polymer elastomers other than the styrene-based elastomers mentioned above, antioxidants, ultraviolet absorbers, light stabilizers, flame retardants, lubricants, antistatic agents, antibacterial agents, fillers, colorants, and the like. The resin composition according to the present invention may, for example, contain fibrous fillers in a proportion of 1 to 25% by mass depending on the application. However, if the filler is contained in a proportion of 10% or more, the impact resistance of the first tube portion may be poor. Therefore, the filler may be omitted, or contained in a proportion of less than 2% by mass, preferably less than 1% by mass, and more preferably less than 0.1% by mass.

[0026] The Charpy impact strength (with notch) of the resin composition according to the present invention is preferably 10 kJ / m at 23°C ± 1°C. ２ More preferably, 20 to 50 kJ / m ２ More preferably 25 to 45 kJ / m ２Furthermore, at 80°C ± 1°C, preferably 20 kJ / m³ ２ More preferably, 25 to 70 kJ / m ２ More preferably 30 to 60 kJ / m ２ This Charpy impact strength can be measured by a method conforming to JIS K 7111.

[0027] The tensile modulus of the resin composition according to the present invention is preferably 1,000 to 3,000 MPa, more preferably 1,800 to 2,900 MPa, and even more preferably 2,000 to 2,800 MPa at 23°C ± 1°C. At 80°C ± 1°C, it is preferably 1,000 to 2,500 MPa, more preferably 1,250 to 2,200 MPa, and even more preferably 1,300 to 2,000 MPa. The tensile fracture strain is preferably 20 to 150%, more preferably 40 to 140%, at 23°C ± 1°C. At 80°C ± 1°C, it is preferably 80 to 180%, and even more preferably 100 to 170%. These tensile modulus and tensile fracture strain can be measured by a method in accordance with JIS K 7161.

[0028] The first pipe section is typically a molded article obtained by subjecting a molten resin composition to injection molding, extrusion molding, press molding, multilayer molding, etc. The resin composition according to the present invention contains a styrene-based elastomer with a styrene unit content of 25 to 65% by mass, and therefore exhibits excellent moldability. The MFR measured under conditions of a temperature of 260°C and a load of 10 kgf is preferably 6 to 25 g / 10 min, more preferably 9.5 to 24 g / 10 min.

[0029] The piping member of the present invention is applicable to all piping commercial materials, and can be particularly a pipe, a tube, a joint, a flange or a valve. The line connecting one end side to the other end side of the piping member may be either linear or curved (including wavy and spiral shapes). Further, in the piping member 1 shown in FIGS. 1 and 2, the cross-sectional shape (the shape depicted by the general outline line of the inner surface of the first pipe portion) inside the piping member through which the liquid flows is a perfect circle, but is not limited thereto, and may be an ellipse, a polygon, or the like. Further, the inner surface of the first pipe portion may have a groove in the longitudinal direction of the piping member. The average value of the inner diameter (caliber) in the cross-sectional shape inside the piping member through which the liquid flows is preferably 10 to 500 mm.

[0030] In the present invention, when the first pipe portion is a single layer of only the first pipe portion, the wall thickness is preferably 2 mm or more, more preferably 2 to 25 mm, and still more preferably 2.5 to 20 mm. In the case of two or more layers, from the viewpoint of elution property, it is preferably 1 mm or more, more preferably 1 to 20 mm, and still more preferably 1.5 to 15 mm. Incidentally, the wall thickness may be either uniform or non-uniform from one end side to the other end side of the piping member.

[0031] In the piping member of the present invention, the inner surface of the first pipe portion preferably has a portion where the surface roughness Rz is 0.5 μm or less. From the viewpoint of the fluidity of the liquid inside the piping member, it is particularly preferable that the surface roughness Rz of all the inner surfaces is 0.5 μm or less. This surface roughness Rz is more preferably 0.3 μm or less.

[0032] As described above, the piping member of the present invention can be provided with an exterior portion, a reinforcing portion, etc. on at least a part of the outer surface of the first pipe portion. The constituent material of this exterior portion 5 is selected according to the purpose, and may be any of resin, metal, etc. Further, the exterior portion and the reinforcing portion may be composed of a plurality of layers.

[0033] The piping member of the present invention gives a high yield when performing product manufacturing (including treatments such as cleaning, pickling, alkali cleaning, sterilization, disinfection, etc.) while passing various liquids through it. For example, it is suitable when supplying high-purity water such as ultrapure water or a liquid containing a predetermined component with a controlled concentration using the piping member of the present invention and performing semiconductor cleaning, etc.

[0034] Hereinafter, the present invention will be specifically described by way of examples.

[0035] 1. Raw materials for the resin composition for pipe members The raw materials for the resin composition for pipe members used in the production of pipes as pipe members are shown below.

[0036] 1-1. Polyphenylene ether-based resin (1) "Noryl 731S-780F" (trade name) manufactured by SHPP Japan Co., Ltd. It is an alloy resin containing polystyrene. (2) "Zylon W5002" (trade name) manufactured by Asahi Kasei Corporation. It is an alloy resin containing less than 40% by mass of polyphenylene ether and more than 40% by mass of polystyrene.

[0037] 1-2. Styrene-based elastomer (1) "D1155" (trade name) manufactured by KRATON. It is a styrene-butadiene-styrene block copolymer with a styrene unit content of 40% by mass. (2) "Tufprene A" (trade name) manufactured by Asahi Kasei Corporation. It is a styrene-butadiene-styrene block copolymer with a styrene unit content of 40% by mass. (3) "Septon 2104" (trade name) manufactured by Kuraray Co., Ltd. It is a styrene-ethylene / propylene-styrene block copolymer with a styrene unit content of 65% by mass. (4) "Tuftec H1051" (trade name) manufactured by Asahi Kasei Corporation. It is a styrene-ethylene / butylene-styrene block copolymer with a styrene unit content of 42% by mass. (5) "Septon 2004F" (trade name) manufactured by Kuraray Co., Ltd. It is a styrene-ethylene / propylene-styrene block copolymer with a styrene unit content of 18% by mass. (6) "G1657" (trade name) manufactured by KRATON. It is a styrene-ethylene / butylene-styrene block copolymer with a styrene unit content of 13% by mass.

[0038] 2. Manufacturing of resin compositions and pipes for piping components and their evaluation Examples 1 to 13 and Comparative Examples 1 to 7 The above raw materials were kneaded in a twin-screw extruder in the proportions shown in Tables 1, 2, and 3 to form pellets (when using polyphenylene ether resin alone, the pelletized resin was used as is without kneading) to obtain resin compositions for piping components. Subsequently, measurements were taken for MFR (temperature: 260°C or 230°C, load: 10 kgf), Charpy impact strength (with notch) at 23°C ± 1°C and 80°C ± 1°C according to JIS K 7111, and tensile modulus and tensile fracture strain at 23°C ± 1°C and 80°C ± 1°C according to JIS K 7161. These results are shown in the respective tables. Furthermore, a pipe (thickness: 3.1 mm, outer diameter: 32 mm, length: 1000 mm) was manufactured using the method described below, and then the inner surface roughness Rz (average value of 10 measurements) was measured using a roughness analyzer equipped with a diamond stylus (tip radius 2 mm).

[0039] <Pipe Manufacturing Method> Using a single-screw extruder at a cylinder temperature of 250°C, pipes made from a polyphenylene ether resin composition with a wall thickness of 3.1 mm and an outer diameter of 32 mm were formed from pellets of polyphenylene ether resin, or pellets made by kneading polyphenylene ether resin and styrene elastomer as described in the examples.

[0040] For reference, commercially available polyvinylidene fluoride pipes were subjected to the same analysis or evaluation as described above, and the results are shown in Table 1.

[0041]

[0042]

[0043]

[0044] The following is clear from Tables 1 to 3. Examples 1 to 13 are examples using resin compositions containing a styrene-based elastomer with a styrene unit content of 25 to 65% by mass, exhibiting excellent impact resistance and high strength against external forces. As a result, it is expected that liquids at temperatures of, for example, 120°C or lower can be supplied without problems through pipes, tubes, fittings, flanges, or valves obtained by molding the resin compositions of Examples 1 to 13.

[0045] The piping member of the present invention can ensure a stable supply when various liquids at temperatures below 120°C are passed through it during product manufacturing or other processes. Taking advantage of this property, it is suitable as a piping member in equipment for manufacturing semiconductor-related products, electronic material-related products, liquid crystal-related products, pharmaceutical-related products, etc., or as a piping member for liquids supplied to such equipment.

[0046] 1: Piping component 3: First pipe section 5: Outer casing

Claims

1. A piping member comprising an inner surface that comes into contact with a liquid, the portion of which is made of a resin composition, wherein the resin composition contains a polyphenylene ether resin and a styrene elastomer, the styrene elastomer is at least one selected from styrene-ethylene-propylene-styrene block copolymer, styrene-ethylene-butylene-styrene block copolymer, and styrene-butadiene-styrene copolymer, and the amount of styrene units contained in the styrene elastomer is 25 to 65% by mass relative to the styrene elastomer.

2. The piping member according to claim 1, wherein the content of the styrene-based elastomer is 3 to 25% by mass relative to the resin composition.

3. The piping member according to claim 1, wherein the melt flow rate (260°C, 10 kgf) of the resin composition is 6.0 to 25 g / 10 min.

4. The piping member according to claim 1, wherein the inner surface has a portion having a surface roughness Rz of 0.5 μm or less.

5. The piping member according to claim 1, wherein the piping member is a pipe, tube, fitting, flange, or valve.

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