Resin composition

Abstract

A resin composition according to one embodiment of the present disclosure comprises: a base resin containing a polyarylene sulfide resin; and at least one higher aliphatic acid compound selected from the group consisting of higher aliphatic acids, higher aliphatic acid esters, and higher aliphatic acid salts.

Description

resin composition

[0001] The present invention relates to a resin composition.

[0002] Patent Document 1 discloses a resin composition for optical communication components containing a base resin containing a polyether ether ketone (PEEK) resin as a main component and silica, wherein the content of the silica in the resin composition for optical communication components is 55 to 75 mass %. Patent Document 1 discloses that the base resin of the resin composition for optical communication components described therein may further contain a polyarylene sulfide (PAS) resin.

[0003] Japanese Patent Publication No. 2021-24971

[0004] As in the resin composition described in Patent Document 1, in order to increase the fluidity of the resulting resin composition, a PAS resin may be added to a base resin containing a resin having a higher melting point than the PAS resin, such as a PEEK resin. A resin composition containing a mixed resin of a PAS resin and a resin having a higher melting point than the PAS resin as a base resin is molded at a temperature higher than the normal molding temperature of the PAS resin. In this way, when a resin composition containing a base resin containing a PAS resin is molded at a temperature higher than the molding temperature of the PAS resin, there is a problem in that the resin composition thickens upon heating.

[0005] An object of one aspect of the present invention is to suppress thickening due to heating of a resin composition containing a base resin including a PAS resin.

[0006] As a result of intensive research to solve the above-mentioned problems, the present inventors discovered for the first time that adding higher fatty acids to a resin composition containing a base resin including a PAS resin can suppress thickening of the resin composition due to heating, and have thus completed the present invention. That is, in order to solve the above-mentioned problems, a resin composition according to one aspect of the present invention contains a base resin including a PAS resin and at least one higher fatty acid selected from the group consisting of higher fatty acids, higher fatty acid esters, and higher fatty acid salts.

[0007] According to one aspect of the present invention, it is possible to suppress thickening due to heating of a resin composition containing a base resin including a PAS resin.

[0008] Hereinafter, one embodiment of the present invention will be described in detail. In this specification, unless otherwise specified, the expression "A to B" representing a range of numerical values ​​means "A or more and B or less."

[0009] [1. Resin Composition] A resin composition according to one embodiment of the present invention contains a base resin including a polyarylene sulfide (PAS) resin and at least one higher fatty acid selected from the group consisting of higher fatty acids, higher fatty acid esters, and higher fatty acid salts.

[0010] According to a resin composition according to one embodiment of the present invention, the resin composition containing a base resin including a PAS resin contains higher fatty acids, thereby suppressing thickening of the resin composition due to heating. This effect is more pronounced when the resin composition according to one embodiment of the present invention is subjected to injection molding. Specifically, by suppressing thickening of the resin composition due to heating, it is possible to suppress the resin composition from thickening with each injection molding shot during injection molding, which would otherwise cause the injection pressure to gradually increase. It can be said that the resin composition according to one embodiment of the present invention is a resin composition with excellent processing stability during injection molding. Note that "heating" here refers to heating at a temperature higher than the normal molding temperature of PAS resin, such as 360°C or higher, or 400°C or higher.

[0011] The resin composition will be described in detail below. <Base Resin> The base resin includes a PAS resin. A PAS resin is a polymer containing 80 mol% or more of repeating units represented by the structural formula [-Ar-S-] (where Ar is an arylene group and S is sulfur). Among PAS resins, polyphenylene sulfide (PPS) resin having repeating units represented by the structural formula [-Ph-S-] (where Ph is a paraphenylene group and S is sulfur) is preferred. One type of PPS may be used alone, or two or more types may be used in combination.

[0012] The PPS resin preferably contains 80 mol % or more, and more preferably 90 mol % or more, of the repeating units, which results in higher crystallinity and melting point than when the PPS resin contains less than 80 mol % of the repeating units.

[0013] The PAS resin can be produced by a known method and is also commercially available. The PAS resin may be selected from those having suitable properties depending on the application and processing conditions of the resin composition.

[0014] The base resin may be composed of only PAS resin, or may be composed of a mixed resin of PAS resin and other resins.

[0015] The type of the other resin is not particularly limited, but from the viewpoint of improving the heat resistance of the resin composition, it is preferable that the other resin has a higher melting point than the PAS resin. Therefore, it is preferable that the base resin is a mixed resin of a PAS resin and a resin having a higher melting point than the PAS resin. In other words, it is preferable that the mixed resin contains a resin having a higher melting point than the PAS resin. Here, the "resin having a higher melting point than the PAS resin" is, for example, a resin having a melting point that is 20°C or higher, preferably 40°C or higher, and more preferably 60°C or higher than the melting point of the PAS resin contained in the mixed resin. Furthermore, the upper limit of the melting point of the "resin having a higher melting point than the PAS resin" is not particularly limited, but from the viewpoint of handleability during molding processing, it is preferable that the difference from the melting point of the PAS resin contained in the mixed resin is 100°C or less. In this specification, the melting point of the resin refers to a value measured by differential scanning calorimetry (DSC).

[0016] The resin having a melting point higher than that of the PAS resin may be a crystalline resin or an amorphous resin.

[0017] The resin having a melting point higher than that of the PAS resin is preferably at least one resin selected from the group consisting of polyetheretherketone (PEEK) resin, polyethersulfone (PES) resin, polyetherimide (PEI) resin, and liquid crystal polymer (LCP) having a melting point of 300°C or higher. These resins can be produced by known methods and are also commercially available. The other resins may be selected from those having suitable properties according to the application and processing conditions of the resin composition.

[0018] Resins with a melting point higher than that of PAS resin are injection moldable and have high crystallinity, and therefore generally have a high melting point, a low coefficient of linear expansion, and low moisture absorption. Therefore, when the base resin is a mixed resin of PAS resin and a resin with a melting point higher than that of the PAS resin, excellent dimensional accuracy can be imparted to injection-molded products. Furthermore, for example, when the resin composition according to one aspect of the present invention is a resin composition for optical communication components, when the resulting optical communication component is heated at a solder reflow temperature, thermal deformation of the optical communication component can be more sufficiently suppressed than when a resin other than a mixed resin of PAS resin and a resin with a melting point higher than that of the PAS resin is used as the base resin.

[0019] Among the examples of resins having a melting point higher than that of the PAS resin described above, PEEK resin is more preferable because it has the highest melting point. When the base resin is a mixed resin of PAS resin and a resin having a melting point higher than that of the PAS resin, the PEEK resin is preferably the main component of the mixed resin. Here, the main component refers to a component whose content in the mixed resin is 50% by mass or more.

[0020] The PEEK resin has a repeating unit represented by the following formula (1). In the above formula (1), R １ , R ２ , R ３ are all substituents, and p, q, and r are each integers of 0 to 4. Examples of the substituent include a halogen group, an alkyl group, an alkenyl group, and an aryl group. It is preferable that p, q, and r are each 0.

[0021] The PEEK resin has n repeating units, where n is a positive integer representing the average degree of polymerization.

[0022] The melt volume rate (MVR) of the PEEK resin is not particularly limited, but is preferably 100 cm ３ In this case, it is preferable that the MVR of the resin composition is 100 cm / 10 minutes or more. ３ In comparison with the case where the time is less than 10 minutes, molding can be carried out more easily.

[0023] The MVR of PEEK resin is 150 cm ３ / 10 minutes or more is more preferable, and 200 cm ３ It is particularly preferable that the time is 10 minutes or more.

[0024] However, the MVR of PEEK resin is 500 cm ３ In this case, it is preferable that the MVR of the PEEK resin is 500 cm ３ The melting point of the PEEK resin is higher than when the melting time exceeds 10 minutes. As a result, for example, when the resin composition according to one embodiment of the present invention is a resin composition for optical communication components, thermal deformation of the optical communication components can be more sufficiently suppressed when the obtained optical communication components are heated at a solder reflow temperature. In addition, the strength of the molded product is further improved. The MVR is a value measured based on ISO 1133 under conditions of 380°C and a load of 5 kg.

[0025] (Base Resin Content) The content of the base resin in the resin composition according to one embodiment of the present invention is not particularly limited. The inclusion of the base resin in the resin composition according to one embodiment of the present invention provides the effect of improving the fluidity of the resin composition. For example, when the resin composition according to one embodiment of the present invention further contains silica, which will be described later, it is preferable that the base resin is contained in an amount of 25 parts by mass or more and 45 parts by mass or less when the total amount of the base resin and silica is 100 parts by mass.

[0026] This increases the fluidity of the resin composition, making it easier to mold injection-molded articles, compared with a case where the base resin content is less than 25 parts by mass, and also provides molded articles with better dimensional accuracy than a case where the base resin content exceeds 45 parts by mass, assuming a total of 100 parts by mass of the base resin and silica.

[0027] From the viewpoint of molding stability, the content of the base resin in the resin composition according to one embodiment of the present invention is more preferably 27 parts by mass or more, and particularly preferably 29 parts by mass or more, when the total amount of the base resin and silica is 100 parts by mass.

[0028] Furthermore, from the viewpoint of the fluidity of the resin composition, the content of the base resin in the resin composition according to one embodiment of the present invention is more preferably 42 parts by mass or less, and particularly preferably 40 parts by mass or less, when the total amount of the base resin and silica is 100 parts by mass.

[0029] When the base resin is a mixed resin of PAS resin and other resins, the content of PAS resin in the mixed resin is preferably 35% by mass or less. For example, when the PAS resin is PPS resin, the content of PPS resin in the mixed resin is more preferably 20% by mass or less. In this case, the heat resistance of the resin composition can be further improved compared to when the content of PPS resin in the mixed resin exceeds 20% by mass, thereby suppressing thermal deformation of molded parts even during heat treatment or use in high-temperature environments. For example, when the resin composition according to one aspect of the present invention is a resin composition for optical communication components, thermal deformation of the optical communication components can be more sufficiently suppressed when heated at solder reflow temperatures compared to when a PAS resin other than PPS resin is used. Furthermore, when the content of PPS resin in the mixed resin is 20% by mass or less, thickening of the resin composition due to heating can be more sufficiently suppressed compared to when the content of PPS resin in the mixed resin exceeds 20% by mass.

[0030] The content of PPS resin in the mixed resin is more preferably 10% by mass or less. Compared to when the content of PPS resin in the mixed resin exceeds 20% by mass, the PPS resin is less likely to melt partially due to high temperatures during solder reflow, and thermal deformation of the molded product can be more sufficiently suppressed.

[0031] However, from the viewpoint of obtaining an effect of improving the fluidity of the resin composition, the content of the PAS resin in the mixed resin is preferably 2% by mass or more, more preferably 5% by mass or more, and even more preferably 10% by mass or more. In this case, the fluidity of the resin composition can be further increased, and therefore the resin composition can be easily molded.

[0032] <Higher fatty acids> The resin composition according to one embodiment of the present invention contains at least one higher fatty acid selected from the group consisting of higher fatty acids, higher fatty acid esters, and higher fatty acid salts, thereby achieving the effect of suppressing thickening due to heating of the resin composition containing a base resin including a PAS resin.

[0033] Here, in this specification, "higher fatty acids" is a general term for higher fatty acids, higher fatty acid esters, and higher fatty acid salts. The higher fatty acids may be used singly or in combination of two or more. The higher fatty acids used in the resin composition according to one aspect of the present invention are preferably higher fatty acids. The higher fatty acids used in the resin composition according to one aspect of the present invention may be higher fatty acid esters or higher fatty acid salts. Higher fatty acid esters and higher fatty acid salts can be decomposed by heating to produce higher fatty acids, and therefore, by adding them to the resin composition according to one aspect of the present invention, the same effects as higher fatty acids can be achieved.

[0034] Examples of higher fatty acids include alkyl groups and alkenyl groups having 9 to 36 carbon atoms, and fatty acids having two or more unsaturated bonds. The hydrogen atoms of the fatty acids may be substituted with hydroxyl groups, and the fatty acids may be branched. Specific examples of higher fatty acids used in the resin composition according to one embodiment of the present invention include saturated fatty acids such as capric acid, undecylic acid, lauric acid, tridecylic acid, myristic acid, pentadecylic acid, palmitic acid, margaric acid, stearic acid, 12-hydroxystearic acid, nonadecylic acid, arachidic acid, heicosylic acid, behenic acid, tricosylic acid, lignoceric acid, cerotic acid, montanic acid, melissic acid, and tetratriacontanoic acid; and straight-chain unsaturated fatty acids such as 4-decenoic acid, 4-dodecenoic acid, palmitoleic acid, α-linolenic acid, linoleic acid, γ-linolenic acid, stearidonic acid, petroselinic acid, oleic acid, elaidic acid, vaccenic acid, eicosapentaenoic acid, docosapentaenoic acid, and docosahexaenoic acid. One type of higher fatty acid may be used alone, or two or more types may be used in combination.

[0035] The higher fatty acid is preferably a fatty acid having 10 to 28 carbon atoms, more preferably a fatty acid having 16 to 28 carbon atoms. The higher fatty acid is preferably at least one higher fatty acid selected from the group consisting of palmitic acid, stearic acid, behenic acid, and montanic acid, more preferably stearic acid.

[0036] Examples of higher fatty acid esters include esters of the above-mentioned higher fatty acids and alcohols. The type of alcohol is not particularly limited. Specific examples of higher fatty acid esters used in the resin composition according to one embodiment of the present invention include myristyl palmitate, butyl stearate, behenyl behenate, octyldodecyl behenate, stearyl stearate, glycerin monopalmitate, glycerin monostearate, glycerin monooleate, glycerin distearate, glycerin tristearate, pentaerythritol monopalmitate, pentaerythritol monostearate, pentaerythritol distearate, pentaerythritol tristearate, and pentaerythritol tetrastearate. One type of higher fatty acid ester may be used alone, or two or more types may be used in combination.

[0037] Examples of higher fatty acid salts include alkali metal salts and alkaline earth metal salts of the above-mentioned higher fatty acids. The higher fatty acid salt used in the resin composition according to one embodiment of the present invention is preferably a metal salt of a long-chain fatty acid having 16 to 36 carbon atoms, and examples include metal stearates such as magnesium stearate, calcium stearate, zinc stearate, aluminum stearate, sodium stearate, and lithium stearate. One type of higher fatty acid salt may be used alone, or two or more types may be used in combination.

[0038] (Content of higher fatty acids) The content of higher fatty acids in the resin composition according to one embodiment of the present invention is not particularly limited. The inclusion of higher fatty acids in the resin composition according to one embodiment of the present invention provides an effect of suppressing thickening of the resin composition due to heating. For example, the content of higher fatty acids in the resin composition according to one embodiment of the present invention can be 0.001 parts by mass or more and 2.0 parts by mass or less, when the total amount of the base resin and silica is 100 parts by mass. As described below, the resin composition according to one embodiment of the present invention may or may not contain silica. For example, when describing the total amount of the base resin and silica, in an embodiment in which silica is not contained, the total amount is the amount of the base resin. The same applies hereinafter.

[0039] From the viewpoint of further improving the effect of suppressing thickening of the resin composition due to heating, the content of higher fatty acids in the resin composition according to one embodiment of the present invention is more preferably 0.005 parts by mass or more, and particularly preferably 0.01 parts by mass or more, when the total amount of the base resin and silica is 100 parts by mass.

[0040] Furthermore, from the viewpoint of the mechanical strength of the resin composition, the content of higher fatty acids in the resin composition according to one embodiment of the present invention is preferably 1.0 part by mass or less, and particularly preferably 0.5 part by mass or less, when the total amount of the base resin and silica is 100 parts by mass.

[0041] <Antioxidant and Layered Double Hydroxide> From the viewpoint of improving the effect of suppressing thickening of the resin composition due to heating, it is preferable that the resin composition according to one aspect of the present invention further contains at least one selected from the group consisting of an antioxidant and a layered double hydroxide. By containing the resin composition according to one aspect of the present invention in combination with the above-mentioned higher fatty acid and at least one selected from the group consisting of an antioxidant and a layered double hydroxide, the effect of suppressing thickening of the resin composition due to heating is further improved.

[0042] The resin composition according to one aspect of the present invention may contain a combination of higher fatty acids and a layered double hydroxide, a combination of higher fatty acids and an antioxidant, or all of higher fatty acids, an antioxidant, and a layered double hydroxide. From the viewpoint of further improving the effect of suppressing thickening of the resin composition due to heating, the resin composition according to one aspect of the present invention more preferably contains all of higher fatty acids, an antioxidant, and a layered double hydroxide.

[0043] The antioxidant and layered double hydroxide used in the resin composition according to one embodiment of the present invention will be specifically described below.

[0044] (Antioxidant) Examples of the antioxidant used in the resin composition according to one embodiment of the present invention include conventionally known antioxidants used for the purpose of preventing oxidation of resin compositions, such as phenol-based antioxidants, phosphorus-based antioxidants, thioether-based antioxidants, etc. These may be used alone or in combination of two or more.

[0045] From the viewpoint of the effect of suppressing thickening of the resin composition due to heating, the antioxidant is preferably at least one selected from the group consisting of phenolic antioxidants and phosphorus-based antioxidants, more preferably at least one selected from the group consisting of hindered phenolic antioxidants and phosphate ester-based antioxidants, and even more preferably a combination of a hindered phenolic antioxidant and a phosphate ester-based antioxidant.

[0046] The phenolic antioxidant and the phosphorus-based antioxidant used in the resin composition according to one embodiment of the present invention will be specifically described below.

[0047] (Phenol-based antioxidant) Examples of the phenol-based antioxidant include conventionally known compounds that have a phenol structure and exhibit antioxidant effects. Specific examples of the phenol-based antioxidant include 2,6-di-tert-butyl-4-methylphenol, 2,6-di-tert-butyl-4-ethylphenol, 2-tert-butyl-4,6-dimethylphenol, styrenated phenol, 2,2'-methylenebis(4-ethyl-6-tert-butylphenol), 2,2'-thiobis-(6-tert-butyl-4-methylphenol), 2,2'-thiodiethylenebis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl] ... nate], 2-methyl-4,6-bis(octylsulfanylmethyl)phenol, 2,2'-isobutylidenebis(4,6-dimethylphenol), isooctyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, N,N'-hexane-1,6-diylbis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionamide, 2,2'-oxamido-bis[ethyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 2 -ethylhexyl-3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate, 2,2'-ethylenebis(4,6-di-tert-butylphenol), 3,5-di-tert-butyl-4-hydroxy-benzenepropanoic acid and C13-15 alkyl ester, 2,5-di-tert-amylhydroquinone, hindered phenol polymer (manufactured by Adeka Palmarol, trade name "AO.OH.98"), 2,2'-methylenebis[6-(1-methylcyclohexyl)-p-crezo] ol], 2-tert-butyl-6-(3-tert-butyl-2-hydroxy-5-methylbenzyl)-4-methylphenyl acrylate, 2-[1-(2-hydroxy-3,5-di-tert-pentylphenyl)ethyl]-4,6-di-tert-pentylphenyl acrylate, 6-[3-(3-tert-butyl-4-hydroxy-5-methyl)propoxy]-2,4,8,10-tetra-tert-butylbenz[d,f][1,3,2]-dioxaphosphobin, hexamethylenebis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, bis[monoethyl(3,5-di-tert-butyl-4-hydroxybenzyl)phosphonate]calcium salt, reaction products of 5,7-bis(1,1-dimethylethyl)-3-hydroxy-2(3H)-benzofuranone with o-xylene, 2,6-di-tert-butyl-4-(4,6-bis(octylthio)-1,3,5-triazin-2-ylamino)phenol, DL-α-tocopherol (vitamin E), 2,6-bis(α-methylbenzyl)-4-methylphenol, bis [3,3-bis-(4'-hydroxy-3'-tert-butyl-phenyl)butanoic acid] glycol ester, 2,6-di-tert-butyl-p-cresol, 2,6-diphenyl-4-octadecyloxyphenol, stearyl (3,5-di-tert-butyl-4-hydroxyphenyl)propionate, distearyl (3,5-di-tert-butyl-4-hydroxybenzyl)phosphonate, tridecyl-3,5-tert-butyl-4-hydroxybenzylthioacetate, thiodiethylenebis[(3,5-di-tert-butyl-4-hydroxy hydroxyphenyl)propionate], 4,4'-thiobis(6-tert-butyl-m-cresol), 2-octylthio-4,6-di(3,5-di-tert-butyl-4-hydroxyphenoxy)-s-triazine, 2,2'-methylenebis(4-methyl-6-tert-butylphenol), bis[3,3-bis(4-hydroxy-3-tert-butylphenyl)butylic acid]glycol ester, 4,4'-butylidenebis(2,6-di-tert-butylphenol), 4,4'-butylidenebis(6-tert-butyl-3-methyl phenol), 2,2'-ethylidenebis(4,6-di-tert-butylphenol), 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane, bis[2-tert-butyl-4-methyl-6-(2-hydroxy-3-tert-butyl-5-methylbenzyl)phenyl]terephthalate, 1,3,5-tris(2,6-dimethyl-3-hydroxy-4-tert-butylbenzyl)isocyanurate, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanurate, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-2,4,6-trimethylbenzene (manufactured by ADEKA Corporation, trade name "ADEKA STAB AO-330"), 1,3,5-tris[(3,5-di-tert-butyl-4-hydroxyphenyl)propionyloxyethyl]isocyanurate, tetrakis[methylene-3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate]methane, 2-tert-butyl-4-methyl-6-(2-acryloyloxy-3-tert-butyl- 5-methylbenzyl)phenol, 3,9-bis[2-(3-tert-butyl-4-hydroxy-5-methylhydrocinnamoyloxy)-1,1-dimethylethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane, triethylene glycol bis[β-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate], stearyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid amide, palmityl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionamide 3-(3,5-dialkyl-4-hydroxyphenyl)propionic acid derivatives such as N,N'-bis[2-[2-(3,5-di-tert-butyl-4-hydroxyphenyl)ethylcarbonyloxy]ethyl]oxamide, N,N'-(1,3-propanediyl)bis[3,5-di-tert-butyl]propionic acid amide, myristyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid amide, lauryl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid amide, -4-hydroxybenzenepropanamide], 1,6-hexanediol bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 4-[[4,6-bis(octylthio)-1,3,5-triazin-2-yl]amino]-2,6-di-tert-butylphenol, N,N'-bis[3-(4-hydroxyphenyl)propanamide], bis[3-[3,5-di(tert-butyl)-4-hydroxyphenyl]propionic acid]thiobisethylene, N,N'-(1,6-hexanediyl)bis[3,5-di-tert-butyl-4-hydroxybenzenepropanamide], octyl 3-(4-hydroxy-3,5-diisopropylphenyl)propionate, calcium bis[3,5-di-tert-butyl-4-hydroxybenzyl(ethoxy)phosphonate], 2,4-bis(octylthiomethyl)-6-methylphenol, 2,5,7,8-tetramethyl-2-(4,8,12-trimethyltridecyl)-2H-1-benzopyran-6-ol, etc. These may be used alone or in combination of two or more.

[0048] (Phosphorus-Based Antioxidant) The phosphorus-based antioxidant can be appropriately selected from conventionally known phosphorus-based antioxidants, such as phosphate ester compounds, phosphite ester compounds, and phosphate compounds.

[0049] Specific examples of the phosphate ester compound and the phosphite ester compound include bis(decyl)pentaerythritol diphosphite, bis(diisodecyl)pentaerythritol diphosphite, bis(nonylphenyl)pentaerythritol diphosphite, bis(tridecyl)pentaerythritol diphosphite, bis(stearyl)pentaerythritol diphosphite, trilaurylthiophosphite heptakis(dipropylene glycol) triphosphite bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite, bis(2,4,6-tri-tert-butylphenyl)pentaerythritol diphosphite, bis(2,4-dicumylphenyl)pentaerythritol diphosphite poly(dipropylene glycol)phenyl phosphite, tetra(tridecyl)isopropylidenediphenol diphosphite, tetra(tridecyl)-4,4'-n-butylidenebis(2-tert-butyl-5-methylphenol)diphosphite, hexa(tridecyl) -1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane triphosphite, tetrakis(2,4-di-tert-butylphenyl)[1,1-biphenyl]-4,4'-diylbisphosphonite, tetrakis(2,4-di-tert-butyl-5-methylphenyl)-4,4'-biphenylidenephosphonite, tetra(C12-C15 alkyl)-4,4'-isopropylidenediphenyl diphosphite, alkyl(C10)bisphenol A phosphite, 4,4'-butylidene-bis(3-methyl-6-te tert-butylphenylditridecyl) phosphite, 2,2'-methylenebis-4,6-di-tert-butylphenyl-2-butyl phosphite, 2,2'-methylenebis-4,6-di-tert-butylphenyl-2-ethylhexyl phosphite, 2,2'-methylenebis-4,6-di-tert-butylphenyl-2-decyl phosphite, 2,2'-methylenebis-4,6-di-tert-butylphenyl-2-dodecyl phosphite, 2,2'-methylenebis-4,6-di-tert-butylphenyl-2-octadecyl phosphite, 2,2'-Ethylenebis(4,6-di-tert-butylphenyl)fluorophosphite, 6-ethylhexyl-2,4,8,10-tetra-tert-butyldibenzo[d.f][1,3,2]dioxaphosphepine, 6-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propoxy]-2,4,8,10-tetra-tert-butyldibenzo[d.f] f][1,3,2]dioxaphosphepine (Sumilizer-GP), triethyl phosphite, tris(2-ethylhexyl)phosphite, tri(decyl)phosphite, triisodecyl phosphite, triisooctyl phosphite, trilauryl phosphite, tris(tridecyl)phosphite, tristearyl phosphite, tris(dipropylene glycol)phosphite, trioleyl phosphite, trisnonylphenyl phosphite, dioleylhydrogen phosphite, diisooctylphenyl phosphite, di(decyl)monophenyl phosphite, diphenyl mono(2-ethylhexyl)phosphite, diphenyl monodecyl phosphite, diphenyl mono(tridecyl)phosphite, Diphenyl octyl phosphite, diphenyl isooctyl phosphite, diphenyl isodecyl phosphite, diphenyl tridecyl phosphite, diisooctyl phosphite, bis(tridecyl) phosphite, bis(2,4-di-tert-butyl-6-methylphenyl)ethyl phosphite, tris[2-[(2,4,8,10-tetra-tert-butyldibenzo[d,f][1,3,2]dioxaphosphepin-6-yl)oxy]ethyl]amine, tris(2,4-di-tert-butylphenyl)phosphite, tetraphenyl dipropyl glycol diphosphite, 2,4,6-tri-tert-butylphenyl-2-butyl-2-ethyl-1,3-propanediol phosphite, tetrakis(2,Examples of suitable esters include 4-di-tert-butylphenyl)biphenylene diphosphonite, hydrogenated bisphenol-A-pentaerythritol phosphite polymer (manufactured by Johoku Chemical Industry Co., Ltd., trade name "JPH-3800"), 2-hydroxyethyl methacrylate acid phosphate (manufactured by Johoku Chemical Industry Co., Ltd., trade name "JPA-514"), stearyl bisphenol-A phosphite polymer (manufactured by Johoku Chemical Industry Co., Ltd., trade name "HBP"), stearyl acid phosphate zinc salt (manufactured by Johoku Chemical Industry Co., Ltd., trade name "JP-518Zn"), and condensed phosphate ester (manufactured by Daihachi Chemical Industry Co., Ltd., trade name "SR-3000"). These may be used alone or in combination of two or more.

[0050] Examples of the phosphate compound include inorganic or organic metal phosphate compounds of ammonium, sodium, calcium, zinc, potassium, aluminum, magnesium, zirconium, barium, lithium, or rare earth elements, etc. These may be used alone or in combination of two or more.

[0051] Specific examples of inorganic phosphate compounds include anhydrous monosodium phosphate, monosodium phosphate monohydrate or dihydrate, anhydrous disodium phosphate, disodium phosphate dihydrate, disodium phosphate heptahydrate, disodium phosphate octahydrate or disodium phosphate dodecahydrate, hexagonal anhydrous trisodium phosphate, cubic anhydrous trisodium phosphate, trisodium phosphate hemihydrate, trisodium phosphate hexahydrate, trisodium phosphate octahydrate, trisodium phosphate dodecahydrate, ammonium dihydrogen phosphate, etc. These may be used alone or in combination of two or more.

[0052] A specific example of the organometallic phosphate compound is sodium 2,2'-methylenebis(4,6-di-tert-butylphenyl)phosphate (manufactured by ADEKA Corporation, trade name "ADEKA STAB Na-11"). These compounds may be used alone or in combination of two or more.

[0053] (Antioxidant Content) The resin composition according to one embodiment of the present invention preferably contains 0.05 parts by mass or more and 0.35 parts by mass or less of an antioxidant when the total amount of the base resin and silica is 100 parts by mass. This improves the effect of suppressing thickening of the resin composition due to heating compared to when the antioxidant content is less than 0.05 parts by mass when the total amount of the base resin and silica is 100 parts by mass. Furthermore, when the total amount of the base resin and silica is 100 parts by mass, the mechanical strength of the resin composition can be ensured compared to when the antioxidant content is more than 0.35 parts by mass.

[0054] From the viewpoint of improving the effect of suppressing thickening of the resin composition due to heating, the content of the antioxidant in the resin composition according to one aspect of the present invention is more preferably 0.1 parts by mass or more, and particularly preferably 0.2 parts by mass or more, when the total amount of the base resin and silica is 100 parts by mass.

[0055] Furthermore, from the viewpoint of ensuring the mechanical strength of the resin composition, the content of the antioxidant in the resin composition according to one aspect of the present invention is preferably 0.3 parts by mass or less, and particularly preferably 0.25 parts by mass or less, when the total amount of the base resin and silica is 100 parts by mass.

[0056] When two or more different types of antioxidants are used in combination, the total content of the antioxidants in the resin composition according to one aspect of the present invention may be within the above-mentioned range. Furthermore, the ratio of the content of the two or more antioxidants may be appropriately adjusted and is not particularly limited. For example, when the antioxidant is a combination of a phenolic antioxidant and a phosphorus-based antioxidant, the ratio of the content of the phenolic antioxidant to the content of the phosphorus-based antioxidant (phenolic antioxidant:phosphorus-based antioxidant) is preferably in the range of 0.2:1 or more and 5:1 or less, more preferably 1:1, in terms of mass ratio, from the viewpoint of improving the effect of suppressing thickening of the resin composition due to heating.

[0057] (Layered double hydroxides) Layered double hydroxides (hereinafter abbreviated as "LDH") are inorganic compounds having a layered crystal structure of hydroxides of divalent metal ions and trivalent metal ions, and having a structure containing anions between the layers of the layered crystal structure (also called a "hydrotalcite structure"), or a calcined product thereof. The divalent metal ions constituting the layered double hydroxides are, for example, Mg ２＋ , Mn ２＋ , Fe ２＋ , Co ２＋ , Ni ２＋ , Cu ２＋ , and Zn ２＋ The trivalent metal ion is, for example, Al ３＋ , Fe ３＋ , Cr ３＋ , Co ３＋ , and In ３＋ The anion may be, for example, OH － , F － , Cl － ,Br － , NO ３ － , CO ３ -, SO ４ ２－ , Fe(CN) ６ ３－ and CH ３ COO － , molybdate ion, polymolybdate ion, vanadate ion, and polyvanadate ion. Layered double hydroxides are sometimes called "hydrotalcite-like compounds."

[0058] As the layered double hydroxide, any natural or synthetic layered double hydroxide can be used as long as it is a compound having a hydrotalcite structure, and these can also be used in combination. Furthermore, the layered double hydroxide can be used without any restrictions on its crystal structure, crystal particle size, etc.

[0059] The layered double hydroxide may have a divalent metal ion of Mg ２＋ and the trivalent metal ion is Al ３＋ Mg-Al-based layered compound in which the divalent metal ion is Mg ２＋and the trivalent metal ion is Fe ３＋ Mg—Fe-based layered compound in which the divalent metal ion is Fe ２＋ and the trivalent metal ion is Fe ３＋ Fe-Fe based layered compound in which the divalent metal ion is Zn ２＋ and the trivalent metal ion is Al ３＋ These may be used alone or in combination of two or more.

[0060] Among these, from the viewpoint of heat resistance and stabilization, the layered double hydroxide is preferably an Mg—Al-based layered compound, and more preferably hydrotalcite.

[0061] (Layered double hydroxide content) The resin composition according to one embodiment of the present invention preferably contains 0.1 to 0.5 parts by mass of layered double hydroxide, relative to 100 parts by mass of the total of the base resin and silica. This improves the effect of suppressing thickening of the resin composition due to heating, compared to when the layered double hydroxide content is less than 0.1 parts by mass, relative to 100 parts by mass of the total of the base resin and silica. Furthermore, compared to when the layered double hydroxide content is more than 0.5 parts by mass, relative to 100 parts by mass of the total of the base resin and silica, outgassing during molding can be suppressed, ensuring moldability.

[0062] From the viewpoint of improving the effect of suppressing thickening of the resin composition due to heating, the content of the layered double hydroxide in the resin composition according to one embodiment of the present invention is more preferably 0.15 parts by mass or more, and particularly preferably 0.2 parts by mass or more, when the total amount of the base resin and silica is 100 parts by mass.

[0063] Furthermore, from the viewpoint of suppressing outgassing during molding, the content of the layered double hydroxide in the resin composition according to one embodiment of the present invention is preferably 0.4 parts by mass or less, and particularly preferably 0.3 parts by mass or less, when the total amount of the base resin and silica is 100 parts by mass.

[0064] <Inorganic Filler> The resin composition according to one embodiment of the present invention may not contain an inorganic filler, but preferably further contains an inorganic filler, which micro-reinforces the material and can impart functions such as electrical conductivity, surface slipperiness, and smoothness to the resin composition according to one embodiment of the present invention.

[0065] Examples of inorganic fillers include conventionally known general-purpose inorganic filling materials that are added to resin compositions, such as: - fibrous fillers such as glass fiber, carbon fiber, whiskers, ceramic fiber, and metal fiber; - granular and powdery fillers such as talc, carbon black, graphite, titanium dioxide, silica, mica, calcium carbonate, calcium sulfate, barium carbonate, magnesium carbonate, magnesium sulfate, barium sulfate, oxysulfate, tin oxide, alumina, kaolin, silicon carbide, metal powder, glass powder, glass flakes, and glass beads.

[0066] Examples of whiskers include boron, alumina, silica, and silicon carbide. Examples of ceramic fibers include gypsum, potassium titanate, magnesium sulfate, and magnesium oxide. Examples of metal fibers include copper, aluminum, and steel. One type of inorganic filler may be used alone, or two or more types may be used in combination.

[0067] The inorganic filler is preferably silica. By further adding silica to the resin composition according to one aspect of the present invention, a molded article can be easily formed, and the obtained molded article can be imparted with excellent dimensional accuracy. Furthermore, for example, when the resin composition according to one aspect of the present invention is a resin composition for optical communication components, thermal deformation of the obtained optical communication components can be sufficiently suppressed even when the optical communication components are heated at a solder reflow temperature.

[0068] Examples of silica used in one embodiment of the present invention include amorphous silica (fused silica) and crystalline silica (quartz, cristobalite, etc.).

[0069] The silica may be either amorphous silica or crystalline silica, but amorphous silica is preferred as the silica used in one embodiment of the present invention. In this case, amorphous silica has lower hardness than crystalline silica, and therefore can more sufficiently prevent damage to equipment used in molding and processing the resin composition.

[0070] The silica may be spherical or pulverized amorphous, but spherical is preferred, as this improves the fluidity of the material when blended with the base resin and the dimensional accuracy of the molded product compared to when pulverized amorphous silica is used instead of spherical silica.

[0071] When the silica has a spherical shape, it is particularly preferred that the silica is produced by a fusion process.

[0072] The sphericity of silica is generally expressed by circularity, and the circularity is preferably 0.80 or more. In this case, optical communication components with a lower anisotropy of the linear expansion coefficient can be molded. The circularity is more preferably 0.85 or more, and particularly preferably 0.90 or more. Here, the circularity of silica is defined by taking a projection image of each silica particle and using the perimeter of the projection image and the perimeter of the equivalent circle according to the following formula (2): (Circularity) = (Perimeter of Equivalent Circle) / (Perimeter of Particle Projected Image) (2) Specifically, the circularity is measured using a flow particle image analyzer FPIA-1000 manufactured by Sysmex Corporation, and the average value of the measured values ​​is calculated as the circularity. Typically, the number of particles sampled is about 200.

[0073] In the above formula (2), the "equivalent circle" refers to a virtual circle having the same area as the projected image of the silica particle to be measured; if the particle is perfectly spherical, the projected image will also be perfectly circular, and the circularity will be 1. If the perimeter of one projected particle image is L and the area is S, the circularity can be calculated using the following formula: Circularity = 4πS / L ２

[0074] The average particle size of the silica is not particularly limited, but is preferably 1 μm or more. In this case, the resin composition has higher fluidity and is more excellent in moldability than when the average particle size of the silica is less than 1 μm, and therefore the dimensional accuracy of the molded product obtained by molding the resin composition is further improved.

[0075] However, the average particle size of the silica is preferably 30 μm or less, which can improve the mechanical strength and dimensional accuracy of the resin composition compared to when the average particle size of the silica exceeds 30 μm.

[0076] The average particle size is a value measured by a laser diffraction scattering particle size distribution measuring device.

[0077] In one embodiment of the present invention, a portion of the silica may be replaced with an inorganic filler having a thermal expansion coefficient lower than that of silica. As such an inorganic filler having a low thermal expansion coefficient, a known inorganic filler can be used, such as a negative thermal expansion (NTE) inorganic filler.

[0078] (Inorganic Filler Content) The resin composition according to one embodiment of the present invention contains 30 parts by mass or more and 75 parts by mass or less of inorganic filler, when the total amount of the base resin and the inorganic filler is 100 parts by mass. This allows for better dimensional accuracy to be imparted to molded articles compared to when the inorganic filler content is less than 30 parts by mass, when the total amount of the base resin and the inorganic filler is 100 parts by mass. Furthermore, when the total amount of the base resin and the inorganic filler is 100 parts by mass, the resin composition has higher fluidity and can more easily mold molded articles, when compared to when the inorganic filler content is more than 75 parts by mass.

[0079] From the viewpoint of dimensional stability, the content of the inorganic filler in the resin composition according to one embodiment of the present invention is more preferably 58 parts by mass or more, and particularly preferably 60 parts by mass or more, when the total amount of the base resin and the inorganic filler is 100 parts by mass.

[0080] Furthermore, from the viewpoint of the fluidity of the resin composition, the content of the inorganic filler in the resin composition according to one embodiment of the present invention is preferably 73 parts by mass or less, and particularly preferably 71 parts by mass or less, when the total amount of the base resin and the inorganic filler is 100 parts by mass.

[0081] The total content of the base resin and inorganic filler in the resin composition according to one embodiment of the present invention is 98% by mass or more, preferably 99% by mass or more, based on the total amount (100% by mass) of the resin composition. The upper limit of the total content of the base resin and inorganic filler is, for example, 100% by mass or less, preferably less than 100% by mass, more preferably 99.9% by mass or less, and even more preferably 99.8% by mass or less.

[0082] <Other Components> The resin composition according to one embodiment of the present invention may further contain other components as needed in addition to the components described above, as long as the object of the present invention is not impaired. Examples of other components include optional additives such as weathering agents, lubricants, plasticizers, antistatic agents, and colorants.

[0083] The content of each additive in the resin composition may be adjusted as appropriate from the viewpoint of the performance expression of each additive. Furthermore, from the viewpoint of reducing the influence on the physical properties of the resulting molded article, the total content of the additives in the resin composition is preferably 1% by mass or less, and more preferably 0.5% by mass or less, based on the total amount (100% by mass) of the resin composition.

[0084] <Uses of Resin Composition> A resin composition according to one embodiment of the present invention can suppress thickening due to heating of a resin composition containing a base resin including a PAS resin. The use of the resin composition according to one embodiment of the present invention is not particularly limited, but by taking advantage of the above-described characteristics, it can be suitably used as a resin composition for injection molding. By subjecting the resin composition according to one embodiment of the present invention to injection molding, it is possible to suppress thickening of the resin composition with each shot during injection molding, and thus suppress a gradual increase in injection pressure. Therefore, the resin composition according to one embodiment of the present invention can be used as a resin composition for injection molding.

[0085] Furthermore, since the resin composition according to one aspect of the present invention is a resin composition that has excellent processing stability in injection molding as described above, it can be suitably used as a composition for, for example, optical communication parts, sliding parts such as gears that require dimensional accuracy, electronic parts, etc. Therefore, the resin composition according to one aspect of the present invention can be a resin composition for optical communication parts, a resin composition for sliding parts, a resin composition for electronic parts, etc.

[0086] <Properties and Form of Resin Composition> The level of the thickening suppression effect of the resin composition according to one embodiment of the present invention is not particularly limited, but for example, the longer the thickening time obtained by the long-term retention evaluation test described in the Examples below, the better. For example, based on the thickening time of a resin composition having the same composition except that it does not contain higher fatty acids, layered double hydroxides, or antioxidants, the longer the thickening time of the resin composition according to one embodiment of the present invention is preferably, and the thickening time is preferably 1.3 times or more of the standard, more preferably 1.5 times or more, and even more preferably 2 times or more. Specific examples of such thickening times are, for example, 30 minutes or more, more preferably 40 minutes or more, more preferably 50 minutes or more, and even more preferably 60 minutes or more.

[0087] The resin composition having a thickening time of 30 minutes or more has a sufficiently high effect of suppressing thickening due to heating, and therefore has good molding stability in, for example, injection molding, and is therefore suitable for use as a resin composition for producing molded articles by injection molding.

[0088] The form of the resin composition according to one aspect of the present invention is not particularly limited, and may be any form, such as powder, granules, pellets, etc. The resin composition according to one aspect of the present invention is preferably in the form of pellets, since it is easy to subject to injection molding.

[0089] <Method for Producing Resin Composition> The resin composition according to one embodiment of the present invention can be obtained by powder-mixing the base resin, the higher fatty acids, etc., followed by melt-kneading. Kneading can be performed using a kneader such as a single-screw extruder or a twin-screw kneading extruder.

[0090] [2. Molded Article] A molded article obtained by molding the resin composition according to one embodiment of the present invention is also included in the scope of the present invention. Next, the molded article according to one embodiment of the present invention will be described.

[0091] The molded article according to one aspect of the present invention includes the resin composition according to one aspect of the present invention described above. The resin composition according to one aspect of the present invention in the molded article according to one aspect of the present invention has already been described, so description thereof will not be repeated here.

[0092] The resin composition described above can easily mold a molded article and can impart excellent dimensional accuracy to the molded article. Furthermore, for example, when the molded article is an optical communication component, the optical communication component can be sufficiently prevented from thermal deformation even when heated at a solder reflow temperature. Therefore, the optical communication component according to one aspect of the present invention has excellent appearance and dimensional accuracy, and can be sufficiently prevented from thermal deformation even when heated at a solder reflow temperature.

[0093] Examples of molded products include optical communication parts; sliding parts such as gears that require dimensional accuracy; and electronic parts. Examples of optical communication parts include ferrules for optical connectors and sleeves for housing ferrules. Among these, the present invention is particularly effective for ferrules for optical connectors that require extremely high dimensional accuracy and are sometimes mounted on circuit boards and subjected to solder reflow.

[0094] The optical connector of the ferrule for optical connector may be a single-core optical connector or a multi-core optical connector. Examples of the ferrule include an MT ferrule, an SC ferrule, and an LC ferrule.

[0095] In addition to gears, examples of sliding parts that require dimensional accuracy include rotary bearings, linear guides, etc. Examples of electronic parts include motor insulators, etc.

[0096] <Method for Producing Molded Article> A molded article according to one aspect of the present invention can be produced by molding the above-described resin composition by, for example, injection molding or transfer molding.

[0097] [Summary] The resin composition according to aspect 1 of the present invention contains a base resin containing a polyarylene sulfide resin and at least one higher fatty acid selected from the group consisting of higher fatty acids, higher fatty acid esters, and higher fatty acid salts.

[0098] In the resin composition according to Aspect 2 of the present invention, in Aspect 1, the higher fatty acids are preferably higher fatty acids.

[0099] In the resin composition according to Aspect 3 of the present invention, in Aspect 1 or Aspect 2, the higher fatty acid is preferably stearic acid.

[0100] The resin composition according to Aspect 4 of the present invention is preferably the resin composition according to any one of Aspects 1 to 3, further comprising a layered double hydroxide.

[0101] In the resin composition according to Aspect 5 of the present invention, in Aspect 4, the layered double hydroxide is preferably hydrotalcite.

[0102] The resin composition according to Aspect 6 of the present invention is preferably any one of Aspects 1 to 5, further comprising an antioxidant.

[0103] In the resin composition according to Aspect 7 of the present invention, in the above-mentioned Aspect 6, it is preferable that the antioxidant is at least one selected from the group consisting of hindered phenol-based antioxidants and phosphate ester-based antioxidants.

[0104] The resin composition according to aspect 8 of the present invention is any one of aspects 1 to 7, wherein the base resin is a mixed resin of a polyarylene sulfide resin and a resin having a melting point higher than that of the polyarylene sulfide resin, and the content of the polyarylene sulfide resin in the mixed resin may be 35 mass% or less.

[0105] In the resin composition according to Aspect 9 of the present invention, in Aspect 8, the resin having a melting point higher than that of the polyarylene sulfide resin may further include at least one resin selected from the group consisting of polyether ether ketone resins, polyether sulfone resins, polyether imide resins, and liquid crystalline resins having a melting point of 300°C or higher.

[0106] The resin composition according to Aspect 10 of the present invention is any one of Aspects 1 to 8, wherein the polyarylene sulfide resin is a polyphenylene sulfide resin.

[0107] The resin composition according to Aspect 11 of the present invention is any one of Aspects 1 to 9, and may further contain silica.

[0108] A resin composition according to a twelfth aspect of the present invention is a resin composition for injection molding in any one of the first to tenth aspects.

[0109] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in the embodiments are also included in the technical scope of the present invention.

[0110] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples.

[0111] [Raw Materials for Resin Composition] The raw materials for the resin compositions used in the Examples and Comparative Examples are as follows.

[0112] <Base Resin> The base resin used was either the following PPS resin alone or a mixed resin obtained by mixing the following PPS resin with the following PEEK resin in a specific ratio: (PPS Resin) Tosoh Corporation, trade name "#140". Melting point: 283°C. (PEEK Resin) Daicel-Evonik Ltd., trade name "1000P". p, q, and r in the formula (1) are 0; MVR measured at 380°C under a load of 5 kg according to ISO 1133: 150 cm ３ / 10 min. Melting point 345°C.

[0113] <Higher fatty acids> Stearic acid (product name "Sakura Stearic Acid", manufactured by NOF Corporation)

[0114] <Antioxidants> (Phenol-based antioxidants) Hindered phenol-based antioxidant (manufactured by ADEKA Corporation, trade name "ADEKA STAB AO-330", 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-2,4,6-trimethylbenzene) (Phosphorus-based antioxidants) Phosphate ester-based antioxidant (manufactured by Daihachi Chemical Industry Co., Ltd., trade name "SR-3000", condensed phosphate ester)

[0115] <Layered double hydroxide> Hydrotalcite (product name "DHT-4C", manufactured by Kyowa Chemical Industry Co., Ltd.)

[0116] <Silica> Surface-treated spherical amorphous silica (trade name "TSS-6 vinylsilane treated", manufactured by Tatsumori Co., Ltd., circularity: 0.93, average particle size: 5 μm) was used.

[0117] [Examples 1 to 4, Comparative Examples 1 to 5] The components were uniformly dry-blended using a Henschel mixer in the compounding ratios shown in Table 1, and then melt-kneaded at a resin temperature of 380 to 410°C using a twin-screw kneading extruder (product name "TEM37SS", manufactured by Toshiba Machine Co., Ltd.) to obtain pellets of the resin composition. In Table 1, the unit of compounding amount is parts by mass, and the values ​​shown are values ​​when the total amount of the base resin and silica is 100 parts by mass.

[0118] [Long-term retention evaluation] Pellets of the resin composition of Example 1 were charged into a small batch kneader (product name "Labo Plastomill (registered trademark)", manufactured by Toyo Seiki Seisakusho, Ltd.), and the molten resin was kneaded for a long time at a barrel temperature of 360°C to 400°C and 30 rpm, and the rotational torque of the screw was measured. The rotational torque of the screw at the start of kneading was defined as the initial torque, and the time required for the rotational torque of the screw to become twice the initial torque was defined as the thickening time. The thickening time was also measured in the same manner for each of the resin compositions of Examples 2 to 4 and Comparative Examples 1 to 5.

[0119] Based on the measurement results of the thickening time, the thickening suppression ability of the resin composition due to heating was evaluated on a three-point scale of A to C according to the following criteria: A: The thickening time was 1.5 times or more longer than that of Comparative Example 1. B: The thickening time was longer than that of Comparative Example 1. C: The thickening time was shorter than that of Comparative Example 1. C indicates poor thickening suppression ability, B indicates good thickening suppression ability, and A indicates even better thickening suppression ability.

[0120] [Results] The results are shown in Table 1.

[0121]

[0122] As can be seen from a comparison between Example 1 and Comparative Example 1, by adding hydrotalcite and stearic acid to PPS containing silica, it was possible to suppress thickening of the resin composition due to heating.

[0123] Furthermore, by further adding other antioxidants to these, it was possible to further suppress thickening of the resin composition due to heating. As shown in Examples 2 and 3, the effect of suppressing thickening of the resin composition due to heating was in the order of phenol-based >> phosphorus-based.

[0124] Furthermore, the results of Comparative Examples 3, 4, and 5 revealed that the effect of suppressing thickening of the resin composition due to heating was such that the following order was observed: phenolic antioxidant only (Comparative Example 3) >> hydrotalcite only (Comparative Example 4) = phosphorus-based antioxidant only (Comparative Example 5).

[0125] Furthermore, by adding a combination of hydrotalcite, stearic acid, and multiple antioxidants, thickening of the resin composition due to heating could be suppressed (Example 4). However, when stearic acid was not added, the thickening suppression effect was poor (Comparative Example 2).

[0126] The above results demonstrate that the addition of stearic acid to a resin composition containing a base resin including a polyarylene sulfide resin can suppress thickening of the resin composition due to heating.

[0127] The resin composition according to one aspect of the present invention has the effect of suppressing thickening of the resin composition due to heating, and therefore can be suitably used, for example, as a resin composition for injection molding. Furthermore, the resin composition according to one aspect of the present invention has excellent molding stability during injection molding, and therefore can be suitably used, for example, as a resin composition for optical communication parts.

Claims

1. A resin composition comprising a base resin containing a polyarylene sulfide resin and at least one higher fatty acid selected from the group consisting of higher fatty acids, higher fatty acid esters, and higher fatty acid salts.

2. The resin composition according to claim 1, wherein the higher fatty acids are higher fatty acids.

3. The resin composition according to claim 1 or 2, wherein the higher fatty acid is stearic acid.

4. The resin composition according to any one of claims 1 to 3, further comprising a layered double hydroxide.

5. The resin composition according to claim 4, wherein the layered double hydroxide is hydrotalcite.

6. The resin composition according to any one of claims 1 to 5, further comprising an antioxidant.

7. The resin composition according to claim 6, wherein the antioxidant is at least one selected from the group consisting of hindered phenol-based antioxidants and phosphate ester-based antioxidants.

8. A resin composition according to any one of claims 1 to 7, wherein the base resin is a mixed resin of a polyarylene sulfide resin and a resin having a melting point higher than that of the polyarylene sulfide resin, and the content of the polyarylene sulfide resin in the mixed resin is 35 mass% or less.

9. The resin composition according to claim 8, wherein the resin having a melting point higher than that of the polyarylene sulfide resin is at least one resin selected from the group consisting of polyether ether ketone resins, polyether sulfone resins, polyether imide resins, and liquid crystalline resins having a melting point of 300°C or higher.

10. The resin composition according to any one of claims 1 to 9, wherein the polyarylene sulfide resin is a polyphenylene sulfide resin.

11. The resin composition according to any one of claims 1 to 10, further comprising an inorganic filler.

12. The resin composition according to any one of claims 1 to 11, which is a resin composition for injection molding.

Images