Method for manufacturing polyarylene sulfide resin molded articles and composite structures

Abstract

To provide a method for manufacturing a polyarylene sulfide (PAS) resin molding which is small in environmental load, and improves reactivity of the surface by a simple method.SOLUTION: A method for manufacturing a PAS resin molding includes a step (1) of melting and molding a PAS resin composition containing a PAS resin to obtain a molding, and a step (2) of annealing the molding, wherein the molding in the step (1) contains an amorphous part of the PAS resin, and the step (2) brings the molding into contact with an aqueous solution of the PAS resin having a glass transition temperature of -30°C or higher.SELECTED DRAWING: None

Description

[Technical Field]

[0001] This invention relates to a method for manufacturing polyarylene sulfide resin molded articles and composite structures. [Background technology]

[0002] Polyarylene sulfide resins (hereinafter abbreviated as "PAS resin"), typified by polyphenylene sulfide resin (hereinafter abbreviated as "PPS resin"), have excellent chemical resistance due to the crystallinity of the surface of molded products and are widely used in electrical and electronic components, automotive parts, water heater parts, textiles, films, and other applications.

[0003] On the other hand, PAS resin has low affinity with other materials due to its excellent chemical resistance, and because it does not have reactive functional groups in its basic framework, there have been issues with bonding strength due to chemical interactions when bonded with other materials. For this reason, the surface of molded products is sometimes pre-treated to make them hydrophilic before bonding, and several methods for doing so have been disclosed.

[0004] For example, it has been disclosed that polar functional groups can be generated on the resin surface by incorporating a photocatalyst into PPS resin and irradiating it with long-wavelength ultraviolet light (Patent Document 1, etc.). However, if the photocatalyst remains on the surface of the molded product, it may accelerate the decomposition of the resin by ultraviolet light, potentially resulting in poor durability. It has also been disclosed that hydrophilic functional groups can be exposed on the surface of PPS resin by treating the surface with an electrolyzed solution with a sulfuric acid concentration of 60-90% by weight (Patent Document 2, etc.). However, this method requires specific equipment and the environmental impact of wastewater must be considered, making it impractical. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 10-168397 [Patent Document 2] Japanese Patent Publication No. 2019-81927 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] Therefore, the problem that this invention aims to solve is to provide a method for manufacturing PAS resin molded articles with improved surface reactivity in a simple manner that has a low environmental impact. Furthermore, it aims to provide a method for manufacturing composite molded articles using such molded articles. [Means for solving the problem]

[0007] As a result of various studies, the inventors of the present invention have found that the reactivity of the surface of a molded product containing an amorphous portion, which is obtained by melt-molding a PAS resin composition, can be improved by contacting it with an aqueous solution at a temperature above the glass transition temperature of the PAS resin, and have completed the present invention.

[0008] In other words, the present invention relates to a method for manufacturing a PAS resin molded article, comprising the steps of (1) melt-molding a PAS resin composition containing PAS resin to obtain a molded article, and (2) annealing the molded article, characterized in that the molded article obtained in step (1) includes an amorphous portion of PAS resin, and step (2) involves contacting the molded article with an aqueous solution of PAS resin with a glass transition temperature of -30°C or higher.

[0009] Furthermore, the present invention relates to a method for manufacturing a composite structure obtained by joining a PAS resin molded article obtained by the manufacturing method described above with a resin member made of a thermoplastic resin composition. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a method for manufacturing PAS resin molded articles with improved surface reactivity in a way that is environmentally friendly and simple. [Modes for carrying out the invention]

[0011] Hereinafter, an embodiment of the present invention will be described in detail. However, the scope of the present invention is not limited to the embodiment described here, and various modifications can be made without departing from the spirit of the present invention. Further, when a plurality of upper limit values and lower limit values are described for specific parameters, any upper limit value and lower limit value can be combined to form a suitable numerical range.

[0012] <Method for manufacturing PAS resin molded product> The method for manufacturing a PAS resin molded product of the present invention is characterized by having a step (1) of melt-molding a PAS resin composition containing a PAS resin to obtain a molded product, and a step (2) of annealing the molded product. This will be described in detail below.

[0013] <Step (1)> The manufacturing method of the present invention has a step (1) of melt-molding a PAS resin composition containing a PAS resin to obtain a molded product. The PAS resin composition used in the present invention is formulated with a PAS resin as an essential component.

[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 moiety represented by the general formula (1) is particularly the R in the formula 1 and R 2 are preferably hydrogen atoms from the viewpoint of the mechanical strength of the PAS resin. In that case, 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) are exemplified.

[0018]

Chemical formula

[0019] Further, the PAS resin contains not only the structural moieties represented by the general formulas (1) and (2), but also the following structural formulas (5) to (8)

[0020]

Chemical formula

[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 invention is not particularly limited, but in order to achieve a good balance between fluidity and mechanical strength, the melt viscosity (V6) measured at 300°C is preferably in the range of 1 Pa·s or more, preferably in the range of 1000 Pa·s or less, more preferably in the range of 500 Pa·s or less, and even more preferably in the range of 200 Pa·s or less. However, the melt viscosity (V6) is measured using a Shimadzu flow tester, CFT-500D, at 300°C and 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] (Non-Newtonian exponents) The non-Newtonian index of the PAS resin used in this invention is not particularly limited, but it is preferably in the range of 0.90 or more and 2.00 or less. However, in this invention, 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 the ratio of orifice length (L) to orifice diameter (D), L / D = 40. The closer the non-Newtonian index (N value) is to 1, the closer the structure is to linear, and the higher the non-Newtonian index (N value), the more branched the structure is.

[0025]

number

[0026] (Amount of terminal carboxyl groups) The amount of terminal carboxyl groups in the PAS resin used in the present invention is not particularly limited, but is preferably in the range of 10 μmol / g or more, more preferably in the range of 20 μmol / g or more, and more preferably in the range of 180 μmol / g or less, and more preferably in the range of 160 μmol / g or less. This range is preferable because it exhibits excellent surface reactivity of the molded article. However, in the present invention, the amount of terminal carboxyl groups in the PAS resin is the value measured by the method described in the examples.

[0027] (Manufacturing method) There are no particular limitations on the method for producing PAS resin, 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 polymerization of 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 water-containing sulfidating agent into a mixture containing a heated polar organic 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 polar organic 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 polar organic 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, alcohols, etc., 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, aliphatic hydrocarbons, etc. (solubilable in the polymerization solvent used and at least poor solvent for the PAS resin) Methods include adding a certain solvent as a precipitating agent to precipitate solid products such as PAS resin and inorganic salts, then filtering, washing with water, and drying; (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, washing with water, filtering, adding an acid or base during the water washing as needed, 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. In either post-treatment method, by adding an acid or base during the water washing process to adjust the pH, the reactivity, crystallization rate, sodium content, zeta potential, etc., of the PAS resin can be controlled, and the pH after the hot water washing process can be controlled to be in the range of 6.5 to 11.5, more preferably in the range of 6.5 to 8.5.

[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] The PAS resin composition used in this invention may contain other components besides PAS resin as optional components as needed. If the optional component has a reactive functional group, the PAS resin molded product after annealing will contain more reactive functional groups and therefore exhibit superior bonding strength.

[0031] The PAS resin composition used in the present invention may optionally contain an elastomer as an optional component. By including the elastomer, the toughness and thermal shock resistance of the PAS resin molded product can be further enhanced. 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.

[0032] 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, and the proportion in which it is blended is not particularly limited. For example, it is preferably 0.01 parts by mass or more, more preferably 0.1 parts by mass or more, even more preferably 1 part by mass or more, preferably 30 parts by mass or less, more preferably 20 parts by mass or less, and even more preferably 15 parts by mass or less, per 100 parts by mass of PAS resin.

[0033] The PAS resin composition used in the present invention 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, it is preferably in the range of 0.01 parts by mass or more, more preferably 0.1 parts by mass or more, preferably 10 parts by mass or less, and more preferably 5 parts by mass or less, 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.

[0034] The PAS resin composition used in the present invention 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.

[0035] In addition to the above components, the PAS resin composition used in the present invention may optionally contain 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, polyarylene 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 included, 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 specified in general terms. For example, the proportion of synthetic resin to be included in 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. In other words, the proportion of PAS resin to the total of PAS resin and synthetic resin is preferably in the range of (100 / 115) or more by mass, and more preferably in the range of (100 / 105) or more.

[0036] Furthermore, the PAS resin composition used in the present invention may also contain, as necessary, other known and conventional additives such as colorants, antistatic agents, antioxidants, heat stabilizers, UV stabilizers, UV absorbers, foaming agents, flame retardants, flame retardant aids, rust inhibitors, and mold release agents (metal salts or esters of fatty acids with 18 to 30 carbon atoms, including stearic acid and montanic acid, polyolefin waxes such as polyethylene, etc.). These additives are not essential components, and for example, the amount is preferably 0.01 parts by mass or more per 100 parts by mass of PAS resin, preferably 1000 parts by mass or less, more preferably 100 parts by mass or less, and even more preferably 10 parts by mass or less, and can be adjusted as appropriate according to the purpose and application so as not to impair the effects of the present invention.

[0037] The method for producing the PAS resin composition used in the present invention is not particularly limited, but examples include a method of melt-kneading PAS 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.

[0038] Melt mixing can be carried out by heating to a temperature range in which the resin temperature is above the melting point of the PAS 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 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.

[0039] 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.

[0040] After melt-kneading, the resin composition is preferably 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.

[0041] The melt molding of the PAS resin composition in this project is not particularly limited as long as it is a known method. For example, it can be used for various moldings such as injection molding, compression molding, composite, sheet, pipe extrusion molding, drawing molding, blow molding, transfer molding, etc. When molding by injection molding, various molding conditions are not particularly limited, and it can be molded by a generally common method. For example, in an injection molding machine, after passing through the step of melting the PAS resin composition in a temperature range where the resin temperature is above the melting point of the PAS resin, preferably in a temperature range of the melting point + 10°C or more, more preferably in a temperature range of the melting point + 10°C to the melting point + 100°C, and even more preferably in a temperature range of the melting point + 20°C to the melting point + 50°C, it can be injected into the mold from the resin discharge port and molded. At that time, the mold temperature can also be set within a known temperature range, for example, room temperature (about 23°C) to 300°C, preferably 150°C or less. The lower the mold temperature, the faster the resin is quenched, so the proportion of the amorphous part in the molded product increases. However, if it is too low, the change in resin fluidity during molding is large, and the solidification rate increases, making it easy to cause molding defects. Therefore, it is advisable to adjust it to an appropriate range according to the shape of the molded product.

[0042] The molded product obtained by melt molding the PAS resin composition in this step contains an amorphous part of the PAS resin. The molded product containing an amorphous part in the present invention refers to a molded product containing PAS resin showing amorphous properties on the surface and / or inside. Here, the amorphous part refers to the part where the PAS resin is solidified in an amorphous state. The proportion of the contained amorphous part is not particularly limited, but is preferably 70% by mass or more, more preferably 80% by mass or more, and even more preferably 90% by mass or more. The confirmation of the proportion of the amorphous part can be carried out by differential scanning calorimetry or FT-IR measurement. For example, when using FT-IR measurement, it can be evaluated using the peak intensity at a wavelength of 1074 cm -1 derived from the amorphous part and the peak intensity at a wavelength of 1093 cm -1 derived from the crystalline part. The larger the value of (peak intensity at 1074 cm -1 ) / (peak intensity at 1093 cm -1 ), the larger the proportion of the amorphous part.

[0043] <Step (2)> Step (2) is a process of annealing the molded product obtained in step (1), which involves contacting the molded product with an aqueous solution of PAS resin at or above the glass transition temperature of -30°C. Here, "at or above the glass transition temperature of -30°C" means a temperature higher than 30°C below the glass transition temperature. That is, for example, if the glass transition temperature of the resin is 90°C, it is sufficient to contact the product with the aqueous solution at a temperature of 60°C or higher.

[0044] The aqueous solution to be brought into contact with the molded article in this invention is not particularly limited as long as it contains water, and any known solution can be used, including water alone. As the solvent to be mixed with water, for example, alcohol-based solvents and ketone-based solvents are preferred. The proportion of water in the aqueous solution is preferably 80 parts by mass or more, and more preferably 90 parts by mass or more.

[0045] Furthermore, the aqueous solution is preferable if it contains an acid, as this can promote the protonation of the reactive functional groups of the PAS resin and resin composition, resulting in excellent reactivity. Examples of acids used here include hydrochloric acid, sulfuric acid, carbonic acid, acetic acid, oxalic acid, and citric acid, with acetic acid and oxalic acid being preferred among these. The amount of acid added in this step is not particularly limited, but for example, the amount can be adjusted so that the pH of the aqueous solution is preferably 5.0 or lower, more preferably 3.0 or lower.

[0046] The temperature at which the molded product is brought into contact with the aqueous solution is not particularly limited as long as it is above the glass transition temperature of the PAS resin -30°C, but it is preferably above -20°C and more preferably above the glass transition temperature. Furthermore, from the viewpoint of workability and power cost, it is more preferably 150°C or lower and even more preferably 135°C or lower. Within this range, an excellent balance is achieved between the power cost and processing time involved in the crystallization of the PAS resin molded product.

[0047] The time for which the molded product is in contact with the aqueous solution is not particularly limited, but it is preferably 1 hour or more, more preferably 5 hours or less, and more preferably 10 hours or less, and even more preferably 5 hours or less. Within this range, an excellent balance is achieved between the power cost and processing time related to the crystallization of the PAS resin molded product.

[0048] After annealing by contact with an aqueous solution, it is preferable to remove the aqueous solution from the molded product before use. In this invention, the method for removing the aqueous solution from the molded product is not particularly limited, and known methods and equipment can be used. For example, methods such as air drying, heating dryers, hot air dryers, vacuum dryers, and microwave dryers can be used. The temperature at which this occurs is not particularly limited, but from the viewpoint of reducing power costs and maintaining surface reactivity, a temperature range below the glass transition temperature of the PAS resin is preferred, and more preferably below the glass transition temperature of -30°C. Furthermore, this process may be carried out in air or in an inert gas such as nitrogen gas.

[0049] In this process, annealing refers to a process that sufficiently crystallizes the PAS resin contained in the molded product. Sufficient crystallization can be confirmed, for example, by observing no peaks originating from crystallization during the process of heating the molded product from room temperature to the melting point of the PAS resin using the method described in the examples, as measured by DSC. The degree of crystallinity of the PAS resin when no peaks are observed depends on the structure of the resin and is not particularly limited, but is generally between 40% and 60% by mass. Within this range, the molded product can exhibit good mechanical properties and chemical resistance.

[0050] The PAS resin molded product that has undergone steps (1) and (2) described above exhibits excellent surface reactivity because reactive functional groups are exposed and present on the surface. Reactive functional groups include reactive functional groups present at the ends of the PAS resin that are incorporated as essential components in the resin molded product (for example, functional groups containing oxygen or nitrogen atoms), and reactive functional groups contained in materials incorporated as optional components. Specifically, these include hydroxyl groups, carboxyl groups, amino groups, thiol groups, etc. The exposure of these functional groups on the surface can be evaluated, for example, by X-ray photoelectron spectroscopy (XPS) measurement. Specifically, this can be evaluated by measuring the concentration of functional groups on the surface of the molded product according to the method described in the examples. In this invention, the surface refers to the area where chemical interactions occur at the interface of the members during bonding.

[0051] Furthermore, the PAS resin molded product obtained through steps (1) and (2) described above has a zeta potential in the range of -70 to -50 mV, preferably in the range of -60 to -50 mV, measured by the flow potential method under pH 7.8 to 8.2 conditions. In this range, the amount of reactive functional groups present at the molecular ends of the PAS resin constituting the molded product tends to be high, and therefore the molded product exhibits excellent responsiveness. The zeta potential of the molded product can be measured by the method described in the examples.

[0052] The reason for these effects is not entirely clear, but it is presumed to be due to the following mechanism. Specifically, when a PAS resin molded product containing amorphous regions is brought into contact with an aqueous solution of PAS resin at or above its glass transition temperature of -30°C, the PAS resin becomes fluid, and molecular chain rearrangement occurs in the amorphous regions. At this time, hydrophilic functional groups contained in the molded product, such as carboxyl groups present at the ends of the PAS resin, become more easily exposed at the interface between the molded product and the aqueous solution. Since these hydrophilic functional groups are more reactive than the main chain of the PAS resin, they are thought to contribute to the bonding strength with other materials as reactive functional groups. Furthermore, because the molecular arrangement state of the outermost surface of the molded product differs from that of the bulk material, it is thought to remain fluid even at the glass transition temperature of -30°C. It should be noted that the above mechanism is merely a hypothesis, and any other reasons for the effects of the present invention are also included within the technical scope of the present invention.

[0053] <Method for manufacturing composite structures> Furthermore, one of the other embodiments of the present invention relates to a method for manufacturing a composite structure obtained by joining a PAS resin molded product obtained by the manufacturing method described above with other members. Other members that can be used in the present invention include resin members made of thermoplastic resin compositions, resin members made of thermosetting resin compositions, metal members, and the like. Hereinafter, the metal members and resin members that are joined with the molded product of this disclosure, as well as the metals and resins that form them, may be collectively referred to as "counterparts."

[0054] The thermoplastic resin used in the resin component made from the thermoplastic resin composition used in the present invention is not particularly limited as long as it does not impair the effects of the present invention, and known thermoplastic resins can be used. Examples include polyester resin, polyamide resin, polyimide resin, polyetherimide resin, polycarbonate resin, polyphenylene ether resin, polysulfone resin, polyethersulfone resin, polyetheretherketone resin, polyarylene sulfide resin, polyetherketone resin, polyarylate resin, polyethylene resin, polypropylene resin, polytetrafluoroethylene resin, polydifluoroethylene resin, polystyrene resin, ABS resin, phenolic resin, urethane resin, liquid crystal polymer, etc., and these may be used individually or in combination. In addition, the above-mentioned thermoplastic elastomers, silane coupling agents, fillers, additives, etc. can be blended as optional components.

[0055] The thermosetting resin used in the resin member made from the thermosetting resin composition applicable to this embodiment is not particularly limited as long as it does not impair the effects of the present invention, and known thermosetting resins can be used. Examples include epoxy resins such as bisphenol-type epoxy resins, novolac-type epoxy resins, epoxy resins having a polyarylene ether structure, and epoxy resins having an alicyclic structure and an aromatic structure in the repeating unit; silicone resins such as condensation-type silicone resins and addition-type silicone resins; and phenolic resins such as novolac-type phenolic resins and bisphenol-type phenolic resins. These can be used individually or in combination. In addition, as optional components, the above-mentioned fillers, curing agents (e.g., amine-type curing agents, phenolic resin-type curing agents, acid anhydride-type curing agents, latent curing agents, etc.), curing accelerators (e.g., phosphorus compounds, tertiary amines, imidazoles, organic acid metal salts, Lewis acids, amine complex salts, etc.), and various additives can be incorporated.

[0056] The thermosetting resin composition can be bonded to the PAS resin molded product by curing it after contact, or by using a pre-cured composition. In this invention, the curing agent for curing the thermosetting resin is not particularly limited as long as it is commonly used as a curing agent for thermosetting resins, but examples include amine-type curing agents, phenol resin-type curing agents, acid anhydride-type curing agents, latent curing agents, etc. These curing agents can be used alone or in combination of two or more. Furthermore, a curing accelerator can be used in combination as appropriate, as long as it does not impair the effects of the present invention.

[0057] The metal components used in the present invention are not particularly limited as long as they do not impair the effects of the present invention, and known metal components can be used. Examples include aluminum, copper, stainless steel, magnesium, iron, titanium, or alloys containing these materials. More specifically, examples include iron alloys (hereinafter referred to as "iron alloys"), which are mainly composed of iron, i.e., 20% by mass or more, more preferably 50% by mass or more, and even more preferably 80% by mass, and also contain carbon, silicon, manganese, chromium, tungsten, molybdenum, phosphor, titanium, vanadium, nickel, zirconium, boron, etc., as well as aluminum alloys (hereinafter referred to as "aluminum alloys"), which are mainly composed of aluminum and also contain copper, manganese, silicon, magnesium, zinc, nickel, etc., as well as magnesium alloys (hereinafter referred to as "magnesium alloys"), which are mainly composed of magnesium and also contain zinc, aluminum, zirconium, etc., as well as copper alloys (hereinafter referred to as "copper alloys"), which are mainly composed of copper and also contain zinc, tin, phosphorus, nickel, magnesium, silicon, chromium, etc., as well as titanium alloys (hereinafter referred to as "titanium alloys"). Of these, iron, iron alloys, aluminum alloys, magnesium alloys, copper alloys, and titanium alloys are more preferably selected, and iron alloys, aluminum alloys, and magnesium alloys are even more preferably selected. The shape of the metal member is not particularly limited, and examples include those processed into flat plates, curved plates, rods, cylinders, blocks, etc., by plastic deformation by pressing, punching, cutting, polishing, electrical discharge machining, or other material removal processes. In addition, it may be a film-like material such as metal foil.

[0058] Furthermore, the metal member may have a roughened surface. Known methods can be used for surface roughening, including, for example, (1) immersion in an erosive aqueous solution or suspension, (2) anodizing, and (3) mechanical cutting by blasting or laser processing. Of these, (1) immersion in an erosive aqueous solution or suspension, or (2) anodizing is particularly preferred as a method for roughening the surface of the metal member. When surface treating the metal member, it is preferable to process the metal member into a predetermined shape by cutting, plastic deformation by pressing, punching, cutting, grinding, electrical discharge machining, etc., before forming the fine uneven surface described above.

[0059] A primer layer may be formed on the surface of a metal component that has undergone surface treatment. The material constituting the primer layer is not particularly limited, but it usually consists of a primer resin material containing a resin component. The primer resin material is not particularly limited, and known materials can be used. Specifically, known polyolefin primers, epoxy primers, urethane primers, etc., can be mentioned. The method for forming the primer layer is not particularly limited, but for example, it can be formed by coating a solution of the above-mentioned primer resin material or an emulsion of the above-mentioned primer resin material onto the metal component that has undergone the surface treatment. Solvents that can be used to make a solution include toluene, methyl ethyl ketone (MEK), and dimethylphosphoamide (DMF). Alimhatic hydrocarbon media and water can be used as media for the emulsion.

[0060] The method for joining the resin molded article of this disclosure to a mating material is not particularly limited as long as it does not impair the effects of the present invention, and known methods and apparatus can be used. For example, this could include a method of melt-joining the mating material and the molded article of this disclosure at a temperature at which a portion of the resin composition of this disclosure flows, or a method of joining by melt-molding the mating material to the molded article of this disclosure.

[0061] One method for joining a mating material by melt-molding the resin composition of the present disclosure is to perform a so-called insert molding method, which involves inserting the resin molded product of the present disclosure into the mold of an injection molding machine, and then performing injection molding using the thermoplastic resin composition. There are no particular restrictions on the apparatus and manufacturing method in the insert molding method; commercially available equipment can be used, or it can be carried out according to conventional methods.

[0062] A method for joining a molded resin product of this disclosure to a mating material at a temperature at which a portion of the resin molded product of this disclosure melts includes joining the mating material and the molded product of this disclosure by heating them in contact, or joining them after heating and then bringing them into contact, and then cooling them. 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 for these joining methods can be commercially available equipment or carried out according to conventional methods.

[0063] Furthermore, the joining member of this disclosure also includes a manner in which a metal member is joined to the molded article of this disclosure by plating. For example, a metal plating layer can be formed on the surface of the molded article of this disclosure by electroplating, electroless plating, or a combination thereof.

[0064] The electroless plating method described above is a method of forming an electroless plating layer (film) consisting of a metal film by depositing a metal such as copper contained in the electroless plating solution by contacting the surface of a molded product according to the disclosure. The electroplating method described above is a method of forming an electroplating layer (metal film) by applying an electric current while an electroplating solution is in contact with the surface of the electroless plating layer (film) formed by the electroless plating treatment described above, thereby depositing a metal such as copper contained in the electroplating solution onto the surface of the electroless plating layer (film) formed by the electroless treatment, which is placed on a cathode.

[0065] Furthermore, the method for manufacturing the joining member of this disclosure may include a step of roughening the molded article and the mating material of this disclosure. For example, a method for roughening a resin member may include a chemical etching method using a strong acid solution, or a physical etching method such as sandblasting or liquid honing, and a method for roughening a metal member may include the roughening treatment described above.

[0066] <Application> Products using molded articles and composite structures obtained by the manufacturing method or processing method of the present invention are not particularly limited and can be used for a wide range of applications, such as: electrical and electronic components such as connectors, printed circuit boards, and encapsulated molded products; automotive parts such as lamp reflectors and various electrical components; interior materials for various buildings, aircraft, and automobiles; injection-molded and compression-molded products such as OA equipment parts, camera parts, and watch parts; extrusion-molded and pultruded products such as fibers, films, sheets, and pipes; and 3D-printed products. [Examples]

[0067] The present invention will be described below using examples and comparative examples, but it is not limited to these examples. Unless otherwise specified, "%" and "parts" refer to mass.

[0068] <Rating>

[0069] (1) DSC evaluation The molded products used in the Reference Examples, Examples, and Comparative Examples, both before and after annealing, were used as test specimens. Using a differential scanning calorimeter (Perkin Elmer 'DSC8500'), the presence or absence of exothermic peaks associated with crystallization was evaluated when the temperature was increased from 40°C to 350°C at a heating rate of 20°C / min. The results are shown in Table 1. In this evaluation, if the test specimen does not contain amorphous regions, the glass transition temperature (Tg) and the exothermic peak associated with crystallization (Tc) are not observed.

[0070] (2) Determination of the amount of terminal carboxyl groups in PAS resin The powders of each PPS resin used were pressed at 350°C and then rapidly cooled to produce amorphous films, which were then measured using a Fourier transform infrared spectrometer (hereinafter abbreviated as "FT-IR spectrometer"). Of the infrared absorption spectra, the 630.6 cm⁻¹ value was measured. -1 1705cm² relative to absorbance -1 The relative intensity of the absorbance was determined, and the carboxyl group content in the measurement sample (hereinafter abbreviated as "total carboxyl group content") was determined using a calibration curve prepared separately by the method described later. The carboxyl group content is expressed in moles per 1 g of the resin mixture, and its unit is expressed as [μmol / g]. The calibration curve was prepared by the following method. First, a predetermined amount of 4-chlorophenylacetic acid was added to a PAS resin prepared so that the carboxylate salt was contained at the molecular ends without acid treatment, and after thorough mixing, a film similar to the above was prepared and measured using an FT-IR instrument. A calibration curve was created by plotting the relative intensity ratio of the absorbance at the two wavelengths mentioned above against the carboxyl group content calculated from the amount of 4-chlorophenylacetic acid added. The results are shown in Table 1.

[0071] (3) Evaluation of carboxyl group content on molded product surface by X-ray photoelectron spectroscopy (XPS) Each molded product obtained in the Reference Examples, Examples, and Comparative Examples was used as a test specimen and evaluated using an X-ray photoelectron spectrometer (AXIS-ULTRA, Shimadzu Corporation). Measurements were performed using monochromatic AlKα rays under conditions of 15kV voltage, 10mA current, and a spot diameter of 600×700μm, and the evaluation was based on the size of the COO peak (288.6eV). The results are shown in Table 1. Due to the detection capability of the instrument, values ​​of 1.0% or less are indicated as "<1.0" in the table.

[0072] (4) Zeta potential measurement The molded products obtained in the Reference Examples, Examples, and Comparative Examples were used as test specimens. After degreasing the surface of each test specimen with acetone, the zeta potential values ​​of the surface of each test specimen were measured using the flow potential method under the following measurement conditions with a solid-only zeta potential meter, SurPASS3 (Anton Paar). The results are shown in Table 1. "Measurement conditions" • Electrolyte: 1 mmol / L aqueous KCl solution ·Measurement temperature: 22~26℃ pH: 8.0

[0073] <Example 1> PPS resin powder (linear type, carboxyl group content: 152 μmol / g) was heated to 310°C using a compression molding machine (NF-37HH model, manufactured by Shinto Metal Industries Co., Ltd.), pressurized at 5 MPa for 1 minute, and then rapidly cooled in a mold at 20°C to obtain a molded product (100 mm × 100 mm × 7 mm). The obtained molded product was immersed in 100°C water for 1 hour. After that, it was removed from the water and air-dried at room temperature.

[0074] <Example 2> A molded article was obtained using powdered PPS resin (linear type, carboxyl group content: 94 μmol / g) in the same manner as in Example 1. The obtained molded article was immersed in water at 100°C for 1 hour. After that, it was removed from the water and air-dried at room temperature.

[0075] <Example 3> A molded article was obtained using PPS resin powder (linear type, carboxyl group content: 47 μmol / g) in the same manner as in Example 1. The obtained molded article was immersed in water at 100°C for 1 hour. After that, it was removed from the water and air-dried at room temperature.

[0076] <Example 4> The molded product, prepared in the same manner as in Example 3, was immersed for 1 hour in a mixed solution of water and acetic acid at 100°C (water:acetic acid = 95 parts by mass: 5 parts by mass). After that, it was removed from the water and air-dried at room temperature.

[0077] <Comparative Example 1> The molded product, prepared in the same manner as in Example 3, was immersed in methanol at 100°C under reflux for 1 hour. Afterward, it was removed from the methanol and air-dried at room temperature.

[0078] <Comparative Example 2> The molded product, prepared in the same manner as in Example 3, was immersed in 40°C water for 1 hour. After that, it was removed from the water and air-dried at room temperature.

[0079] <Comparative Example 3> The molded product was annealed by heating it at 120°C for 3 hours to remove amorphous areas, and then immersed in 100°C water for 1 hour. After that, it was removed from the water and air-dried at room temperature.

[0080] <Reference example 1> Molded products prepared in the same manner as in Example 3 were evaluated without any annealing treatment.

[0081] [Table 1]

[0082] Table 1 shows that the molded articles produced by the method of the examples had a higher proportion of carboxyl groups on their surface and a lower zeta potential compared to the molded articles of the comparative examples, suggesting the presence of more functional groups that contribute to reactivity.

Claims

1. A process (1) to obtain a molded product by melt-molding a polyarylene sulfide resin composition containing polyarylene sulfide resin, and A method for manufacturing a polyarylene sulfide resin molded article, comprising the step (2) of annealing the molded article, The molded product in step (1) above includes an amorphous portion of polyarylene sulfide resin. The above step (2) involves contacting the molded product containing the amorphous portion obtained in step (1) with an aqueous solution of polyarylene sulfide resin with a glass transition temperature of -30°C or higher. A method for producing a polyarylene sulfide resin molded article, characterized in that the amount of terminal carboxyl groups contained in the polyarylene sulfide resin is in the range of 10 to 180 μmol / g.

2. The method for producing a polyarylene sulfide resin molded article according to claim 1, wherein the aqueous solution brought into contact in step (2) contains an acid.

3. The polyarylene sulfide resin composition comprises a substance having a reactive functional group, A method for producing a polyarylene sulfide resin molded article according to claim 1 or 2, wherein the reactive functional group is at least one selected from the group consisting of a hydroxyl group, a carboxyl group, an amino group, and a thiol group.

4. A method for producing a polyarylene sulfide resin molded article according to claim 1 or 2, wherein the zeta potential of the resulting molded article, measured by the flow potential method under conditions of pH 7.8 to 8.2, is in the range of -70 to -50 mV.

5. A method for manufacturing a composite structure, comprising the step of joining a polyarylene sulfide resin molded article obtained by the manufacturing method described in claim 1 or 2 with a resin member made of a thermoplastic resin composition.

6. A method for manufacturing a composite structure, comprising the step of joining a polyarylene sulfide resin molded article obtained by the manufacturing method described in claim 1 or 2 with a resin member made of a thermosetting resin composition, A method for producing a composite structure, wherein the thermosetting resin comprises at least one resin from the group consisting of epoxy resins, silicone resins, and phenolic resins.

7. A method for manufacturing a composite structure, comprising the step of joining a polyarylene sulfide resin molded product obtained by the manufacturing method described in claim 1 or 2 with a metal member.

8. A method for using a polyarylene sulfide resin molded product obtained by the manufacturing method described in claim 1 or 2 as a joining member.

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