Method for manufacturing a composite structure and composite structure

Abstract

To provide a composite structure consisting of a resin tubular molded product and a joint, which has excellent water pressure resistance. [Solution] A method for manufacturing a composite structure comprising a tubular molded article made of a thermoplastic resin composition and a joint, the method comprising the steps of: obtaining a tubular molded article by melt-molding the thermoplastic resin composition; and connecting the tubular molded article and the joint by press-fitting them so that the tubular molded article is on the outside of the joint, wherein the outer diameter of the joint is 3 to 40% larger than the inner diameter of the tubular molded article, and the tensile elongation at break of the thermoplastic resin composition is 70% or more.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a composite structure formed by connecting a tubular molded product made of a thermoplastic resin composition and a joint, and to the composite structure.

Background Art

[0002] In recent years, in the piping members around water supply and hot water supply facilities, members made of new materials have been demanded due to insufficient supply and price fluctuations of copper. In addition, conventional copper pipes have problems such as internal corrosion, corrosion of the outer surface of the pipe by the heat insulating material, and noise caused by water impact. Due to these factors, in piping members around water, resin materials that are easy to process and highly corrosion-resistant have been demanded.

[0003] As one of the thermoplastic materials for piping members in water-related applications, polyarylene sulfide (hereinafter referred to as PAS), typified by polyphenylene sulfide (hereinafter referred to as PPS) resin having excellent mechanical strength and chemical resistance, has been proposed. For example, Patent Document 1 discloses a piping member made of a PPS resin composition characterized by containing 20 to 300 parts by weight of an inorganic filler and 0.06 to 0.19 parts by weight of polyether ether ketone as an organic crystal nucleating agent with respect to​​​​​​​​​​​​​​​​​​​​​​​​​​Therefore, the problem that the present invention aims to solve is to provide a composite structure consisting of a resin tubular molded product and a joint that has excellent water pressure resistance. [Means for solving the problem]

[0007] The inventors completed the present invention after conducting various studies.

[0008] In other words, the present invention encompasses the following aspects. [1] A method for manufacturing a composite structure comprising connecting a tubular molded article made of a thermoplastic resin composition and a joint, A step of obtaining a tubular molded product by melt-molding the thermoplastic resin composition, The process involves connecting the tubular molded product and the fitting by press-fitting them so that the tubular molded product is on the outside of the fitting. The outer diameter of the aforementioned joint is 30-40% larger than the inner diameter of the aforementioned tubular molded product. A method for manufacturing a composite structure, wherein the thermoplastic resin composition has a tensile elongation at break of 70% or more. [2] A method for manufacturing a composite structure, further comprising the step of welding the connection portion formed by press-fitting the tubular molded product and the joint, in the manufacturing method of [1]. [3] A method for producing a composite structure according to [1] or [2], wherein the thermoplastic resin is a PAS resin. [4] Joints and, A tubular molded article made of a thermoplastic resin composition, The connection portion between the joint and the tubular molded product, A composite structure comprising, The aforementioned connection portion is a press-fit structure, and the aforementioned tubular molded product is on the outside of the joint. The outer diameter of the aforementioned joint is 30-40% larger than the inner diameter of the aforementioned tubular molded product. A composite structure wherein the thermoplastic resin composition has a tensile elongation at break of 70% or more. [5] The composite structure according to [4], wherein the connecting portion is further welded. [6] The composite structure according to [4] or [5], wherein the thermoplastic resin is a PAS resin. [7] The composite structure according to [4] to [6], wherein the thermoplastic resin composition has a tensile modulus of 1 GPa or more. [8] The composite structure according to claims [4] to [7], wherein the joint is made of resin or metal. [9] The composite structure according to [5], wherein the welding of the connecting portion is performed by at least one method selected from the group consisting of hot plate welding, vibration welding, infrared welding, infrared vibration welding, ultrasonic welding, high-frequency welding, induction heating welding, rotary welding, laser welding, hot pressing, hot embossing, and friction stir welding.

[10] A composite structure as described in [4] to [9], having a water pressure resistance of 2.5 MPa or more. (However, the water pressure resistance value was measured in accordance with JIS S-3200-1.) [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a composite structure consisting of a resin tubular molded product and a joint, which has excellent water pressure resistance. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is a cross-sectional view of the main part of a composite structure according to one embodiment of the present disclosure. [Modes for carrying out the invention]

[0011] [Composite structures, methods for manufacturing composite structures] A composite structure according to one embodiment of this disclosure will be described below with reference to the drawings. In the drawings used in the following description, the shapes and dimensional relationships of the elements shown may differ from the shapes and dimensional relationships in the actual composite structure. The scope of the present invention is not limited to the embodiment described herein, and various modifications can be made without departing from the spirit of the invention. Furthermore, if multiple upper and lower limits are given for a particular parameter, any combination of these upper and lower limits can be used to create a suitable numerical range.

[0012] Figure 1 is a cross-sectional view of the main part of the composite structure according to this embodiment. In this embodiment, the main part of the composite structure has a tubular molded product 1 made of a thermoplastic resin composition and a joint 2. And it includes a connection part 11 formed by press-fitting so that the tubular molded product is on the outside of the joint. The outer diameter 13 of the joint is 3 to 40% larger than the inner diameter 12 of the tubular molded product. Details of the thermoplastic resin composition will be described later. The manufacturing method of the composite structure will be described later.

[0013] <Thermoplastic composition> The composite structure according to this embodiment has a tubular molded product 1 made of a thermoplastic resin composition as an essential component. The thermoplastic resin applied to this embodiment is preferably a PAS resin.

[0014] The PAS resin has a resin structure having a structure in which an aromatic ring and a sulfur atom are bonded as a repeating unit. Specifically, the following general formula (1)

[0015]

Chemical formula

[0016]

Chemical formula

[0017] Here, the structural part represented by the general formula (1) is particularly R in the formula 1 and R 2From the viewpoint of the mechanical strength of the PAS resin, it is preferable that the atom is a hydrogen atom, and in that case, examples include those bonded at the para position represented by the following formula (3) and those bonded at the meta position represented by the following formula (4).

[0018] [ka] Among these, the bond of the sulfur atom to the aromatic ring in the repeating unit is particularly preferred to be a structure in which it is bonded at the para position as represented by the general formula (3) above, in terms of the heat resistance of the PAS resin.

[0019] Furthermore, the PAS resin includes not only the structural parts represented by the general formulas (1) and (2), but also the following structural formulas (5) to (8).

[0020] [ka] The structural components represented by the above general formulas (1) and (2) may be included in an amount of 30 mol% or less of the total of the structural components represented by the above general formulas (1) and (2). In particular, in this disclosure, it is preferable that the structural components represented by the above general formulas (5) to (8) be 10 mol% or less, from the viewpoint of the heat resistance and mechanical strength of PAS. When the above general formulas (5) to (8) are included in the PAS resin, the bonding mode may be either a random copolymer or a block copolymer.

[0021] Furthermore, the PAS resin may have naphthyl sulfide bonds or the like in its molecular structure, but it is preferable that the amount of naphthyl sulfide bonds is 3 mol% or less, and particularly preferable that it is 1 mol% or less, relative to the total number of moles of other structural parts.

[0022] Furthermore, the physical properties of the PAS resin are not particularly limited as long as they do not impair the effects of the present invention, but are as follows.

[0023] (Melting viscosity) The melt viscosity of the PAS resin used in this embodiment is preferably in the range of 50 to 250 Pa·s, and more preferably in the range of 70 to 150 Pa·s, when measured at 300°C, because it provides a good balance between the dispensing speed and take-up stability during molding. However, the melt viscosity (V6) of the PAS resin is measured using a Shimadzu flow tester, CFT-500D, at 300°C, with a load of 1.96 × 10⁻⁶. 6 The measured melt viscosity was obtained after holding the mixture at Pa and L / D = 10(mm) / 1(mm) for 6 minutes.

[0024] (Weight average molecular weight) The weight-average molecular weight of the PAS resin used in this embodiment is 30,000 to 100,000, and more preferably 35,000 to 50,000, from the viewpoint of molding stability during molding. The weight-average molecular weight of the PAS resin of the present invention is the weight-average molecular weight measured using gel permeation chromatography under the following measurement conditions. Six types of monodisperse polystyrene are used for calibration. Equipment: Ultra-high temperature polymer molecular weight distribution analyzer (SSC-7000, manufactured by Senshu Science Co., Ltd.) Column: UT-805L (manufactured by Showa Denko Corporation) Column temperature: 210℃ Solvent: 1-Chloronaphthalene Measurement method: UV detector (360nm)

[0025] (Non-Newtonian exponents) The non-Newtonian index of the PAS resin used in this embodiment is not particularly limited, but is preferably in the range of 0.95 to 1.50. In this range, the PAS resin composition exhibits excellent mechanical strength. However, in this disclosure, the non-Newtonian index (N value) is a value calculated using the following formula by measuring the shear rate (SR) and shear stress (SS) using a capillary graph under conditions of melting point +20°C and an orifice length (L) to orifice diameter (D) ratio of L / D = 40. A non-Newtonian index (N value) closer to 1 indicates a structure closer to linear, while a higher non-Newtonian index (N value) indicates a more branched structure.

[0026]

number

[0027] (Manufacturing method) The method for producing the PAS resin is not particularly limited, but examples include: (Method 1) polymerizing a dihalogeno-aromatic compound in the presence of sulfur and sodium carbonate, with the addition of a polyhalogeno-aromatic compound or other copolymerizing component if necessary; (Method 2) polymerizing a dihalogeno-aromatic compound in a polar solvent in the presence of a sulfidating agent, with the addition of a polyhalogeno-aromatic compound or other copolymerizing component if necessary; (Method 3) self-condensing p-chlorthiophenol, with the addition of other copolymerizing components if necessary; (Method 4) melt-polymerizing a diiodo-aromatic compound and elemental sulfur under reduced pressure in the presence of a polymerization inhibitor which may have functional groups such as carboxyl groups or amino groups. Among these methods, Method 2 is the most versatile and preferred. During the reaction, alkali metal salts of carboxylic acids or sulfonic acids, or alkali hydroxides may be added to adjust the degree of polymerization. Among the above (manufacturing method 2) methods, there is a method for producing PAS resin by introducing a hydrated sulfidating agent into a mixture containing a heated organic polar solvent and a dihalogeno-aromatic compound at a rate at which water can be removed from the reaction mixture, and reacting the dihalogeno-aromatic compound and the sulfidating agent in the organic polar solvent with a polyhalogeno-aromatic compound as needed, and controlling the amount of water in the reaction system to be in the range of 0.02 to 0.5 moles per mole of the organic polar solvent (see Japanese Patent Publication No. 07-228699), and solid A Particularly preferred is a product obtained by adding a dihalogeno-aromatic compound and, if necessary, a polyhalogeno-aromatic compound or other copolymerizing component in the presence of a rucali metal sulfide and an aprotic polar organic solvent, and reacting the alkali metal hydrosulfide and the alkali metal salt of an organic acid while controlling the amount of alkali metal salt of the organic acid in the range of 0.01 to 0.9 moles per mole of sulfur source and the amount of water in the reaction system to be 0.02 moles or less per mole of aprotic polar organic solvent (see WO2010 / 058713 pamphlet).Specific examples of dihalogenoaromatic compounds include p-dihalobenzene, m-dihalobenzene, o-dihalobenzene, 2,5-dihalotoluene, 1,4-dihalonaphthalene, 1-methoxy-2,5-dihalobenzene, 4,4'-dihalobiphenyl, 3,5-dihalobenzoic acid, 2,4-dihalobenzoic acid, 2,5-dihalonitrobenzene, 2,4-dihalonitrobenzene, 2,4-dihaloanisole, p,p'-dihalodiphenyl ether, 4,4'-dihalobenzophenone, 4,4'-di Examples include halodiphenylsulfones, 4,4'-dihalodiphenyl sulfoxides, 4,4'-dihalodiphenyl sulfides, and compounds having an alkyl group with 1 to 18 carbon atoms in the aromatic ring of each of the above compounds. Examples of polyhalogenoaromatic compounds include 1,2,3-trihalobenzene, 1,2,4-trihalobenzene, 1,3,5-trihalobenzene, 1,2,3,5-tetrahalobenzene, 1,2,4,5-tetrahalobenzene, and 1,4,6-trihalonaphthalene. Furthermore, it is desirable that the halogen atoms contained in each of the above compounds be chlorine atoms and bromine atoms.

[0028] The post-treatment method for the reaction mixture containing the PAS resin obtained by the polymerization step is not particularly limited, but for example, (post-treatment 1) after the polymerization reaction is completed, first the reaction mixture is treated as is, or an acid or base is added, and the solvent is removed under reduced pressure or atmospheric pressure, and then the solid after solvent removal is washed once or twice or more with a solvent such as water, the reaction solvent (or an organic solvent having equivalent solubility to the low molecular weight polymer), acetone, methyl ethyl ketone, or alcohols, and then neutralized, washed with water, filtered and dried, or (post-treatment 2) after the polymerization reaction is completed, the reaction mixture is treated with a solvent such as water, acetone, methyl ethyl ketone, alcohols, ethers, halogenated hydrocarbons, aromatic hydrocarbons, or aliphatic hydrocarbons (solubilable in the polymerization solvent used and poorly soluble in at least PAS). Methods include adding a solvent (as a medium) as a precipitating agent to precipitate solid products such as PAS and inorganic salts, then filtering, washing, and drying them; (post-treatment 3) after the polymerization reaction is complete, adding a reaction solvent (or an organic solvent having equivalent solubility to the low molecular weight polymer) to the reaction mixture and stirring, then filtering to remove the low molecular weight polymer, washing once or twice or more with a solvent such as water, acetone, methyl ethyl ketone, or alcohols, then neutralizing, washing with water, filtering, and drying; (post-treatment 4) after the polymerization reaction is complete, adding water to the reaction mixture and washing with water, filtering, adding acid during water washing as needed for acid treatment, and then drying; (post-treatment 5) after the polymerization reaction is complete, filtering the reaction mixture, washing once or twice or more with the reaction solvent as needed, and then further washing with water, filtering, and drying. Among these methods, method (post-treatment 4) is preferred because it yields a PAS resin having carboxyl groups at the molecular ends of the PAS resin.

[0029] In addition, in the post-treatment methods exemplified above (post-treatment 1) to (post-treatment 5), the drying of the PAS resin may be carried out in a vacuum, in air, or in an inert gas atmosphere such as nitrogen.

[0030] In the PAS resin composition used in this embodiment, the amount of PAS resin blended is preferably 30 to 80 parts by mass, more preferably 40 to 70 parts by mass, per 100 parts by mass of the resin composition. This range is preferable because the resin composition exhibits excellent heat resistance and mechanical strength.

[0031] Furthermore, the PAS resin used in this embodiment can be newly polymerized PAS resin using the method described above, or recycled PAS resin can be used. For example, PAS resin recovered from PAS resin compositions or PAS resin molded products can be used. Specifically, this includes PAS resin obtained by heating PAS resin compositions or PAS resin molded products in an organic polar solvent to dissolve the contained PAS, and then performing the above-described post-treatment on the resulting solution. In addition, mechanically pulverized PAS resin compositions or PAS resin molded products can also be used as PAS resin. Specifically, this includes sprues or runners generated during the manufacture of molded products, recovered as off-spec molded products, or pulverized molded products that have been used as products. In this case, pulverized PAS resin compositions or PAS resin molded products containing components other than PAS resin may be used, but from the viewpoint of mechanical strength, the PAS resin content is preferably 90 parts by mass or more, more preferably 95 parts by mass or more, and even more preferably 98 parts by mass or more.

[0032] The PAS resin composition applicable to this embodiment may optionally contain an elastomer as an optional component. Including the elastomer can further improve the molding stability during molding of tubular molded products and the connectability (processability) when press-fitting the joint and the tubular molded product. From a similar viewpoint, it is preferable to use a thermoplastic elastomer as the elastomer. The thermoplastic elastomer is not particularly limited as long as it does not impair the effects of the present invention, but examples of thermoplastic elastomers include polyolefin-based elastomers, fluorine-based elastomers, and silicone-based elastomers.

[0033] When the elastomer is incorporated, examples include functional groups that can react with at least one group selected from the group consisting of hydroxyl groups, amino groups, carboxyl groups, and carboxyl groups. Examples of such functional groups include epoxy groups, amino groups, hydroxyl groups, carboxyl groups, mercapto groups, isocyanate groups, oxazoline groups, and groups represented by the formula: R(CO)O(CO)- or R(CO)O- (wherein R represents an alkyl group having 1 to 8 carbon atoms). A thermoplastic elastomer having such a functional group can be obtained, for example, by copolymerization of an α-olefin and a vinyl polymerizable compound having the functional group. Examples of α-olefins include 2 to 8 carbon atoms such as ethylene, propylene, and butene-1. Examples of vinyl polymerizable compounds having the aforementioned functional group include α,β-unsaturated carboxylic acids and their alkyl esters such as (meth)acrylic acid and (meth)acrylic acid esters, maleic acid, fumaric acid, itaconic acid and other α,β-unsaturated dicarboxylic acids having 4 to 10 carbon atoms and their derivatives (mono or diesters, and their acid anhydrides, etc.), and glycidyl (meth)acrylate. Among these, ethylene-propylene copolymers and ethylene-butene copolymers having at least one functional group selected from the group consisting of an epoxy group, a carboxyl group, and a group represented by the formula: R(CO)O(CO)- or R(CO)O- (wherein R represents an alkyl group having 1 to 8 carbon atoms) are preferred from the viewpoint of improving toughness and impact resistance. In the present invention, the elastomer is an optional component, but the proportion when blending is not particularly limited. For example, 5 to 50 parts by mass is preferred, 8 to 30 parts by mass is more preferred, and 10 to 25 parts by mass is even more preferred, per 100 parts by mass of PAS resin.

[0034] The PAS resin composition applicable to this embodiment may optionally contain a silane coupling agent as an optional component. The silane coupling agent is not particularly limited as long as it does not impair the effects of the present invention, but silane coupling agents having a functional group that reacts with a carboxyl group, such as an epoxy group, isocyanate group, amino group, or hydroxyl group, are preferred. Examples of such silane coupling agents include epoxy group-containing alkoxysilane compounds such as γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, and β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane; isocyanato group-containing alkoxysilane compounds such as γ-isocyanatopropyltrimethoxysilane, γ-isocyanatopropyltriethoxysilane, γ-isocyanatopropylmethyldimethoxysilane, γ-isocyanatopropylmethyldiethoxysilane, γ-isocyanatopropylethyldimethoxysilane, γ-isocyanatopropylethyldiethoxysilane, and γ-isocyanatopropyltrichlorosilane; amino group-containing alkoxysilane compounds such as γ-(2-aminoethyl)aminopropylmethyldimethoxysilane, γ-(2-aminoethyl)aminopropyltrimethoxysilane, and γ-aminopropyltrimethoxysilane; and hydroxyl group-containing alkoxysilane compounds such as γ-hydroxypropyltrimethoxysilane and γ-hydroxypropyltriethoxysilane. In the present invention, a silane coupling agent is not an essential component, but if it is included, the amount added is not particularly limited as long as it does not impair the effects of the present invention. However, 0.01 to 10 parts by mass, and more preferably 0.1 to 5 parts by mass, is preferred per 100 parts by mass of PAS resin. This range is preferable because the resin composition has good moldability, especially release properties, and the mechanical strength of the molded product is improved.

[0035] The PAS resin composition applicable to this embodiment may optionally contain fillers as components. These fillers may be publicly known and commonly used materials, provided they do not impair the effects of the present invention. Examples include inorganic fillers of various shapes, such as fibrous materials, granular materials, or non-fibrous materials such as plates. Specifically, fibrous fillers such as glass fibers, carbon fibers, silane glass fibers, ceramic fibers, aramid fibers, metal fibers, potassium titanate, silicon carbide, calcium silicate, wollastonite, and natural fibers can be used. Non-fibrous fillers such as glass beads, glass flakes, barium sulfate, clay, pyrophyllite, bentonite, sericite, mica, talc, attapulgite, ferrite, calcium silicate, calcium carbonate, glass beads, zeolite, milled fiber, and calcium sulfate can also be used. Specific examples of surface treatment agents for surface-treating inorganic fillers include epoxy compounds, isocyanate compounds, silane compounds, titanate compounds, borane treatment, and ceramic coatings. Among these, epoxy compounds or silane compounds are preferred. The amount of filler to be blended is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and even more preferably 20 parts by mass or more, per 100 parts by mass of PAS resin. On the other hand, from the viewpoint of obtaining better fluidity and processability of the resin composition and smoothness of the molded product surface, it is more preferably 350 parts by mass or less, even more preferably 300 parts by mass or less, and particularly preferably 250 parts by mass or less, per 100 parts by mass of PAS resin.

[0036] The PAS resin composition applicable to this embodiment may, in addition to the above components, further optionally incorporate synthetic resins (hereinafter simply referred to as "synthetic resins") such as polyester resin, polyamide resin, polyimide resin, polyetherimide resin, polycarbonate resin, polyphenylene ether resin, polysulfone resin, polyethersulfone resin, polyetheretherketone resin, polyetherketone resin, polyarylate resin, polyethylene resin, polypropylene resin, polytetrafluoroethylene resin, polydifluoroethylene resin, polystyrene resin, ABS resin, phenolic resin, urethane resin, and liquid crystal polymer, depending on the application. Although the above synthetic resins are not essential components in the present invention, when they are incorporated, the proportion of the synthetic resin is not particularly limited as long as it does not impair the effects of the present invention, and it will vary depending on the purpose and cannot be defined in general terms. For example, the proportion of synthetic resin to be incorporated into the resin composition according to the present invention may be in the range of 5 parts by mass or more and 15 parts by mass or less per 100 parts by mass of PAS resin.

[0037] Furthermore, the PAS resin composition applicable to this embodiment may also contain, as necessary, other known and conventional additives such as colorants, antistatic agents, antioxidants, heat stabilizers, ultraviolet stabilizers, ultraviolet absorbers, foaming agents, flame retardants, flame retardant aids, rust inhibitors, and mold release agents (such as metal salts or esters of fatty acids having 18 to 30 carbon atoms, including stearic acid and montanic acid, and polyolefin waxes such as polyethylene), as optional components, as long as they do not impair the effects of the present invention. For example, 0.01 to 500 parts by mass is preferred, 0.1 to 250 parts by mass is more preferred, and 0.5 to 100 parts by mass is even more preferred, per 100 parts by mass of PAS resin.

[0038] The physical properties of the resin composition applicable to this embodiment are not particularly limited as long as they do not impair the effects of the present invention, but are as follows.

[0039] (Tensile elongation at fracture) The tensile elongation at break of the resin composition applicable to this embodiment is preferably 70% or more, and more preferably 90% or more. Within this range, the tubular molded product exhibits excellent water pressure resistance and joint connectivity (processability) of the resin pipe. The tensile elongation at break in this disclosure is the value measured by the method described in the examples.

[0040] (Tensile modulus of elasticity) The tensile modulus of the resin composition applicable to this embodiment is preferably 1.0 GPa or higher, and more preferably 1.5 GPa or higher. Within this range, the tubular molded product exhibits excellent water pressure resistance. The tensile modulus in this disclosure is the value measured by the method described in the examples.

[0041] <Method for producing thermoplastic resin compositions> The method for producing the thermoplastic resin composition applicable to this embodiment is not particularly limited, but examples include a method of melt-kneading a thermoplastic resin with optional components as needed, or more specifically, a method of uniformly dry-mixing the mixture using a tumbler or Henschel mixer as needed, and then melt-kneading it in a twin-screw extruder.

[0042] Melt mixing can be carried out by heating to a temperature range in which the resin temperature is above the melting point of the thermoplastic resin, preferably a temperature range of 10°C or higher above the melting point, more preferably 10°C or higher above the melting point, even more preferably from 20°C or higher above the melting point, preferably 100°C or lower above the melting point, and more preferably 50°C or lower above the melting point.

[0043] As the melting and mixing machine, a twin-screw extruder is preferred from the viewpoint of dispersibility and productivity. For example, it is preferable to melt and mix while appropriately adjusting the discharge rate of the resin component in the range of 5 to 500 kg / hr and the screw rotation speed in the range of 50 to 500 rpm, and it is even more preferable to melt and mix under conditions where the ratio of these (discharge rate / screw rotation speed) is in the range of 0.02 to 5 kg / hr / rpm. In addition, the addition and mixing of each component to the melting and mixing machine may be done simultaneously or in stages. For example, when other fibrous fillers are added as needed, it is preferable from the viewpoint of dispersibility to introduce them into the extruder from the side feeder of the twin-screw extruder. The position of such a side feeder is preferably such that the ratio of the distance from the resin input section (top feeder) to the total length of the screw of the twin-screw extruder to the side feeder is 0.1 or more, and more preferably 0.3 or more. Furthermore, this ratio is preferably 0.9 or less, and more preferably 0.7 or less.

[0044] It is preferable that, after melt-kneading the resin composition, it is processed by a known method, for example, by extruding the molten resin composition into strands, then into the form of pellets, chips, granules, powder, etc., and then pre-drying as necessary.

[0045] <Tubular molded products> The composite structure according to this embodiment has a tubular molded article 1 as an essential component. The tubular molded article of this disclosure is made of the thermoplastic resin composition described above. The method for manufacturing the tubular molded article by melt molding of the thermoplastic resin composition is not particularly limited as long as it is a known method. For example, it can be subjected to various molding methods such as injection molding, compression molding, extrusion molding, pultrusion molding, blow molding, and transfer molding, but extrusion molding is preferred. Various molding conditions are not particularly limited and can be molded using generally accepted methods. For example, the thermoplastic resin composition may be melted in a molding machine at a temperature range of melting point or higher, preferably melting point + 10°C or higher, more preferably melting point + 10°C to melting point + 100°C, and even more preferably melting point + 20°C to melting point + 50°C, after which it may be molded.

[0046] The size and shape of the tubular molded article applicable to this embodiment are not particularly limited as long as they do not impair the effects of the present invention. For example, the length is preferably 100 to 2000 mm, more preferably 300 to 1500 mm, and even more preferably 500 to 1000 mm. The outer diameter is preferably 3 to 30 mm, more preferably 5 to 20 mm, and even more preferably 10 to 15 mm. The inner diameter is preferably 2 to 28 mm, more preferably 4 to 18 mm, and even more preferably 9 to 14 mm. The wall thickness is preferably 0.1 to 3 mm, more preferably 0.3 to 2 mm, and even more preferably 0.6 to 1.5 mm.

[0047] The difference between the longitudinal diameter and the transverse diameter of the tubular molded product applicable to this embodiment is preferably 0.10 mm or less, more preferably 0.05 mm or less, and even more preferably 0.01 mm or less. Within this range, the tubular molded product exhibits excellent water pressure resistance.

[0048] The tubular molded product applicable to this embodiment may have a section with a different diameter. That is, when the tubular molded product is sliced, it may have a section where at least one of the inner diameter or outer diameter is different. Examples include corrugated tubes, flanged tubes, and joint ring structures. Parts for connecting to joints or pipes can be attached to the section with a different diameter. For example, nuts, screws, flange pins, etc., can be used.

[0049] <Fittings> The composite structure according to this embodiment includes a joint (pipe joint) 2 as an essential component.

[0050] The material of the joint applicable to this embodiment is not particularly limited, and known materials such as resin, metal, and ceramic can be used. In particular, when a resin joint is used, the composite structure has excellent moldability and flexibility, and when a metal joint is used, the composite structure has excellent mechanical strength. In the case of a resin joint, the resin is preferably a thermoplastic resin, more preferably an engineering plastic, and even more preferably a super engineering plastic. In addition, when a resin joint is used, it may consist of a resin composition containing optional components other than resin.

[0051] The shape of the fittings applicable to this embodiment is not particularly limited, and known fittings can be used. For example, fittings in the shape of sockets, nipples, elbows, caps, plugs, flanges, crosses, reducers, bushings, T-joints, and Y-joints can be used.

[0052] The outer diameter 13 of the joint applicable to this embodiment is 3 to 40% larger than the inner diameter 12 of the tubular molded product. More preferably, it is 5 to 30% larger, and even more preferably, 8 to 20% larger. This size does not need to be the same for the entire joint, but refers to the outer diameter of the portion that can connect to the tubular molded product (the portion that can form a connection). For example, it is within 10 cm from the connecting end. Having such an outer diameter allows for excellent adhesion of the connection portion 11 when the tubular molded product 1 is press-fitted so that it is on the outside of the joint, as the two deform together and stress is generated.

[0053] The connection portion 11 between the tubular molded product 1 and the joint 2 is preferably 1.0 to 10.0 cm, more preferably 1.5 to 7.0 cm, and even more preferably 2.0 to 5.0 cm, from the viewpoint of adhesion and workability between the tubular molded product and the joint.

[0054] From the viewpoint of durability, the composite structure of this disclosure is preferably such that its water pressure resistance is 2.5 MPa or higher. From the same viewpoint, it is more preferably 3.0 MPa or higher, and even more preferably 5.0 MPa or higher.

[0055] The method for manufacturing a composite structure according to this embodiment is a method for manufacturing a composite structure comprising connecting a tubular molded article made of a thermoplastic resin composition and a joint, A step of obtaining a tubular molded product by melt-molding the thermoplastic resin composition, The process involves connecting the tubular molded product and the fitting by press-fitting them so that the tubular molded product is on the outside of the fitting. The outer diameter of the aforementioned joint is 30-40% larger than the inner diameter of the aforementioned tubular molded product. The tensile elongation at break of the aforementioned thermoplastic resin composition is 70% or more. Further details are provided below.

[0056] The method of connecting the tubular molded product 1 and the joint 2 by press-fitting them so that the tubular molded product is on the outside of the joint (the method of forming the connection portion 11) is not particularly limited, and publicly known and publicly used devices and methods can be used.

[0057] When combining the tubular molded product 1 and the joint 2, the press-fit portion (connection portion 11) created above can be further welded to improve water pressure resistance. When welding the tubular molded product and the joint, the method is not particularly limited as long as it does not impair the effects of the present invention, and known methods, conditions, and equipment can be used as long as it is a method of melting and welding the tubular molded product. Specifically, examples of methods include hot plate welding, vibration welding, infrared welding, infrared vibration welding, ultrasonic welding, high-frequency welding, induction heating welding, rotary welding, laser welding, hot pressing, hot embossing, and friction stir welding. The equipment and manufacturing methods used in these joining methods can be commercially available or carried out according to conventional methods. In particular, hot plate welding and hot pressing welding are preferred from the viewpoint of improving connection strength as the area of ​​the welded surface increases and from the viewpoint of welding operability.

[0058] <Composition / Applications, etc.> The composite structure according to this embodiment is characterized by its excellent properties such as water pressure resistance, hot water resistance, chemical resistance, and processability, making it suitable for residential equipment such as hot water piping and fuel piping, as well as for automotive, industrial, and commercial machinery applications. Specifically, it can be suitably used for piping components such as hot water storage tanks in water heaters. Furthermore, the composite structure according to this embodiment can be used not only for piping components but also as a composite structure for pipes and fittings in various applications, such as electrical and electronic components, household and office electrical product components, machine-related components such as cleaning jigs, and automotive and vehicle-related components such as various pipes for fuel, exhaust, and intake systems, and can be applied to various other applications as well. [Examples]

[0059] The present invention will be specifically described below with reference to examples. These examples are illustrative and not limiting. Unless otherwise specified, "%" and "parts" refer to mass.

[0060] (Manufacturing Example 1: Synthesis of PPS resin) In a 150-liter autoclave equipped with a pressure gauge, thermometer, condenser, decanter, and a stirring blade, as well as a bottom valve, 22.050 kg (150 mol) of p-dichlorobenzene (p-DCB), 2.974 kg (30 mol) of N-methyl-2-pyrrolidone (NMP), 12.362 kg (150 mol) of 68% NaSH, and 12.500 kg (150 mol) of 48% NaOH were supplied, and the mixture was heated to 173°C under a nitrogen atmosphere while stirring. After distilling off 12.353 kg of water, the autoclave was sealed. During this process, the p-DCB distilled off by azeotrope was separated in the decanter and returned to the autoclave as needed. After dehydration, the autoclave temperature was cooled to 160°C, 29.486 kg (297 mol) of NMP was added, the temperature was raised to 220°C and stirred for 2 hours, then raised to 250°C and stirred for 1 hour. The final pressure was 0.28 MPa. After the reaction was complete, the bottom valve of the autoclave was opened and the mixture was flushed into a 150 L vacuum stirring dryer with stirring blades to remove the NMP. Subsequently, the mixture was stirred under reduced pressure at 150°C for 4 hours to completely remove the NMP, obtaining a mixture of powdered PPS resin and salts. 30 kg of the obtained crude PPS mixture was mixed with 90 kg of ion-exchanged water at 70°C and stirred for 30 minutes, then filtered. 90 kg of ion-exchanged water at 70°C was added to the filtered cake to wash the cake. The mixture was then dried at 120°C for 4 hours to obtain a white powdered PPS resin. The weight-average molecular weight of the obtained PPS resin A-1 was 40,000, and the melt viscosity was 115 Pa·s.

[0061] (Manufacturing Example 2: Preparation of PPS resin composition) Each material was blended according to the composition and proportions listed in Table 1. These blended materials were then fed into a vented twin-screw extruder and melt-kneaded at a resin component discharge rate of 30 kg / hr, a screw rotation speed of 200 rpm, and a set resin temperature of 310°C to obtain resin composition pellets. Glass fibers were fed through a side feeder (S / T ratio 0.5), while the other materials were pre-mixed uniformly in a tumbler and fed through a top feeder.

[0062] (Examples 1-4, Comparative Examples 1-5) The pellets of each resin composition obtained were dried in a 140°C gear oven for 2 hours and supplied to an extrusion machine connected to a pipe molding die, a water-cooled tank capable of vacuum evacuation, a take-up device, and a cutting machine. Molding was performed under the following conditions: single-screw extruder temperature setting of 300°C, sizing diameter of 12.5 mm, take-up speed of 5.0 m / min, and cutting interval of 1 m, yielding tubular molded products with an outer diameter of 12.0 mm, an inner diameter of 10.0 mm, a thickness of 1.0 mm, and a length of 1500 mm.

[0063] (Combination of tubular molded product and fitting) A joint connector (manufactured by MCC Corporation) was used to press-fit the tubular molded product and the fitting. The fitting had an outer diameter of 12 mm (inner diameter of the tubular molded product + 20%) and a thickness of 1.5 mm. The joint was 3.0 cm long, and the fitting was press-fitted so that the tubular molded product was on the outside. If welding was required to connect the tubular molded product and the fitting, the entire connection (3.0 cm) was further contacted with a hot plate heated to 300°C for 10 seconds to perform the welding. <Rating>

[0064] (1) Tensile test Pellets of the resin compositions used in each example and comparative example were supplied to a Sumitomo Heavy Industries injection molding machine (SE-75D-HP) set to a cylinder temperature of 310°C. Injection molding was performed using an ISO Type 1A dumbbell mold with a mold temperature controlled to 140°C to obtain ISO Type-A dumbbell pieces. The tensile modulus and tensile fracture strain of the obtained dumbbell pieces were measured using measurement methods compliant with ISO 527-1 and 527-2. The measurement results are shown in Table 1.

[0065] (2) Evaluation of connectivity In each example and comparative example, when pressing a tubular molded product into a joint to manufacture a composite, tubular molded products that cracked, whitened, or were distorted by more than 20° were evaluated as ×, tubular molded products that were inserted without cracking but distorted by less than 20° were evaluated as △, and tubular molded products that were inserted without whitening or distortion were evaluated as ○. The results are shown in Table 1.

[0066] (3) Water pressure resistance test of tubular molded products (measurement of water pressure fracture strength) One end of each tubular molded product obtained in the examples and comparative examples was sealed, and water was filled to remove air from the tubular molded product. In accordance with the JIS S-3200-1 standard, the other end of the tubular molded product was connected to a hydraulic test pump (TP-50 manufactured by Terada Pump Mfg. Co., Ltd.), and the pressure was increased to 5 MPa / min, and the pressure at the time of rupture was measured. The results are shown in Table 1.

[0067] (4) Water pressure leakage test of composite structures One end of the tubular molded product / joint composite structure obtained in each example and comparative example was sealed, and water was filled to remove air from the composite structure. The other end of the composite structure was connected to a water pressure test pump (TP-50 manufactured by Terada Pump Manufacturing Co., Ltd.), the pressure was increased to 2.5 MPa, and after standing for 2 minutes, it was checked whether water leakage occurred. In each example and comparative example, when the composite structure was pressurized to 2.5 MPa and stood for 2 minutes, composite structures where the joint came off or cracked were evaluated as ×, composite structures where neither the joint came off nor cracked but water leakage occurred from the joint connection part were evaluated as △, and composite structures where no water leakage occurred were evaluated as ○. The results are shown in Table 1.

[0068] [Table 1]

[0069] The ingredients used for each component in Table 1 are as follows: PPS resin: Linear polyphenylene sulfide resin, melt viscosity (V6) 100 Pa·s Thermoplastic elastomer: Ethylene-glycidyl methacrylate-based thermoplastic elastomer, "Bondfast 7M" manufactured by Sumitomo Chemical Co., Ltd. Glass filler: Chopped strand, manufactured by Nippon Electric Glass Co., Ltd., "ECS03T-725H" [Explanation of symbols]

[0070] 1 Tubular molded product 2 joints 11 Connection part 12. Inner diameter of tubular molded product 13 Outer diameter of the fitting

Claims

1. A method for manufacturing a composite structure comprising connecting a tubular molded article made of a thermoplastic resin composition and a joint, A step of obtaining a tubular molded product by melt-molding the thermoplastic resin composition, The process involves connecting the tubular molded product and the fitting by press-fitting them so that the tubular molded product is on the outside of the fitting. The outer diameter of the joint is 3 to 40% larger than the inner diameter of the tubular molded product. A method for manufacturing a composite structure, wherein the thermoplastic resin composition has a tensile elongation at break of 70% or more.

2. A method for manufacturing a composite structure, further comprising the step of welding the connection portion formed by press-fitting the tubular molded product and the joint, in the manufacturing method of claim 1 above.

3. A method for producing a composite structure according to claim 1 or 2, wherein the thermoplastic resin is a polyarylene sulfide resin.

4. Joints and, A tubular molded article made of a thermoplastic resin composition, The connection portion between the joint and the tubular molded product, A composite structure comprising, The aforementioned connection portion is a press-fit structure, and the aforementioned tubular molded product is on the outside of the joint. The outer diameter of the joint is 3 to 40% larger than the inner diameter of the tubular molded product. A composite structure wherein the thermoplastic resin composition has a tensile elongation at break of 70% or more.

5. The composite structure according to claim 4, wherein the connecting portion is further welded.

6. The composite structure according to claim 4 or 5, wherein the thermoplastic resin is a polyarylene sulfide resin.

7. The composite structure according to claim 4 or 5, wherein the tensile modulus of the thermoplastic resin composition is 1 GPa or more.

8. The composite structure according to claim 4 or 5, wherein the joint is made of resin or metal.

9. The composite structure according to claim 5, wherein the welding of the connecting portion is performed by at least one method selected from the group consisting of hot plate welding, vibration welding, infrared welding, infrared vibration welding, ultrasonic welding, high-frequency welding, induction heating welding, rotary welding, laser welding, hot pressing, hot embossing, and friction stir welding.

10. The composite structure according to claim 4 or 5, wherein the water pressure resistance is 2.5 MPa or more. (However, the water pressure resistance is a value measured in accordance with JIS S-3200-1.)

Images