Polyethylene naphthalate resin composition and molded article derived therefrom

Abstract

To provide a polyethylene naphthalate resin composition having superior extrusion capability and mechanical properties and causing reduced mold deposit during injection molding, as well as a molded article derived therefrom.SOLUTION: A polyethylene naphthalate resin composition comprises 10 to 100 pts.wt. of regenerated carbon fiber (component B) relative to 100 pts.wt. of polyethylene naphthalate resin (component A), wherein the regenerated carbon fiber has a sizing agent at least partially bonded thereto, and component B has a 5% weight reduction temperature of at least 460°C in thermogravimetric-differential thermal analysis upon heating in air from room temperature at a rate of 5°C / min.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a resin composition comprising a polyethylene naphthalate resin and recycled carbon fibers, which has excellent extrudability and mechanical properties and has less mold deposit during injection molding, and a molded article made therefrom.

Background Art

[0002] The polyethylene naphthalate resin is a polyester resin having excellent transparency, heat resistance and chemical resistance. Taking advantage of its characteristics, it is used for pharmaceutical containers, household appliances that may come into contact with organic solvents, oils, greases and detergents, housings of electric, electronic and communication equipment, resin frames used in fuel cells, and gaskets.

[0003] In recent years, with the requirements for miniaturization and weight reduction in the field of electric, electronic and communication equipment, and the requirements for higher capacity of fuel cells, improvement of the thin-wall moldability and mechanical properties of resins has been demanded, and cases of filling with carbon fibers having a low specific gravity and obtaining high strength have been increasing.

[0004] On the other hand, from the viewpoint of effective utilization of resources, recycling of carbon fibers has been studied. As a method for recovering recycled carbon fibers (r-CF), for example, Patent Document 1 discloses a method of heating and removing only the matrix resin from carbon fiber reinforced plastic (CFRP) by thermal decomposition. However, since the r-CF obtained from the thermal decomposition of CFRP contains residues derived from the matrix resin, there are many decomposition products, and there is a problem that mold adhesion stains (mold deposits) generated on the mold during injection molding are more than those in the case of using virgin carbon fibers.

[0005] Patent Document 2 discloses a method for manufacturing a resin molded body comprising a polyethylene terephthalate resin, carbon fibers composed of carbon fiber chips regenerated from aircraft end materials, a polyfunctional epoxy compound, and a reaction catalyst. Patent Document 3 discloses pellets formed from a resin composition comprising a thermoplastic resin, recycled carbon fibers, and a compound having an epoxy group. However, all of the patent documents are characterized by using an epoxy group compound in order to bridge the strength difference with virgin CF that occurs when using r-CF. On the other hand, there are epoxy compounds with low heat resistance, and there is a problem that more mold deposits occur when using epoxy compounds.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0007] An object of the present invention is to provide a polyethylene naphthalate resin composition having excellent extrudability and mechanical properties and having few mold deposits during injection molding, and a molded body comprising the same.

Means for Solving the Problems

[0008] As a result of intensive studies, the present inventors have found that by blending a polyethylene naphthalate resin with recycled carbon fibers to which a sizing agent having a specific 5% weight loss temperature adheres at least partially, Furthermore, the inventors have found that the above problems can be achieved, and thus the present invention has been completed. That is, the present invention is as follows.

[0009] 1. A polyethylene naphthalate resin composition containing 10 to 100 parts by weight of (B) recycled carbon fibers (component B) to which a sizing agent is at least partially attached, based on 100 parts by weight of the polyethylene naphthalate resin (component A), wherein the 5% weight loss temperature in thermogravimetric-differential thermal analysis measurement when the temperature of component B is raised from room temperature at a rate of 5 °C / min in air is 460 °C or higher. 2. The polyethylene naphthalate resin composition according to item 1 above, wherein the sizing agent attached to component B is a polyester-based sizing agent. 3. The polyethylene naphthalate resin composition according to item 1 or 2 above, wherein component A is a polyethylene naphthalate resin comprising at least one selected from the group consisting of naphthalene dicarboxylic acid or its ester derivative having 80 to 100 mol% of a dicarboxylic acid component and 0 to 20 mol% of terephthalic acid, isophthalic acid, and their ester derivatives, and the diol component is ethylene glycol. 4. The polyethylene naphthalate resin composition according to any one of items 1 to 3 above, containing 10 to 100 parts by weight of (C) polyetherimide resin (component C) based on 100 parts by weight of component A. 5. A molded article made of the polyethylene naphthalate resin composition according to any one of items 1 to 4 above.

Advantages of the Invention

[0010] According to the present invention, it is possible to provide a polyethylene naphthalate resin composition excellent in extrudability and mechanical properties and having less mold deposit during injection molding, and a molded article made therefrom. The molded article made of the polyethylene naphthalate resin composition of the present invention can be suitably used, for example, in electric and electronic parts, vehicle-related parts, aircraft parts, industrial machine parts, OA equipment parts, housing equipment parts, and various mechanism parts.

Modes for Carrying Out the Invention

[0011] Hereinafter, the details of the present invention will be described.

[0012] Component A The polyethylene naphthalate resin which is Component A of the present invention preferably consists of naphthalenedicarboxylic acid or its ester derivative with a dicarboxylic acid component of 80 to 100 mol% and at least one selected from the group consisting of 0 to 20 mol% of terephthalic acid, isophthalic acid and their ester derivatives, and has ethylene glycol as the diol component. If the naphthalenedicarboxylic acid is less than 80 mol% among the dicarboxylic acid components, the heat resistance may be insufficient.

[0013] The naphthalenedicarboxylic acid component is mainly 2,6-naphthalenedicarboxylic acid and 2,7-naphthalenedicarboxylic acid, but other dicarboxylic acids can be used in combination as long as the properties are not impaired.

[0014] Examples of dicarboxylic acid components other than naphthalenedicarboxylic acid include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, 2-chloroterephthalic acid, 2,5-dichloroterephthalic acid, 2-methylterephthalic acid, 4,4-stilbenedicarboxylic acid, 4,4-biphenyldicarboxylic acid, orthophthalic acid, bisbenzoic acid, bis(p-carboxyphenyl)methane, anthracenedicarboxylic acid, 4,4-diphenyletherdicarboxylic acid, 4,4-diphenoxyethanedicarboxylic acid, 5-Na sulfoisophthalic acid, ethylene-bis-p-benzoic acid, and aliphatic dicarboxylic acids such as adipic acid, sebacic acid, azelaic acid, dodecanedioic acid, 1,3-cyclohexane Examples of the dicarboxylic acid include aliphatic dicarboxylic acids such as 1,3-cyclohexanedicarboxylic acid and 1,4-cyclohexanedicarboxylic acid. Among them, at least one selected from the group consisting of terephthalic acid, isophthalic acid and their ester derivatives is preferable, and terephthalic acid is more preferable. These dicarboxylic acids can be used alone or in combination of two or more.

[0015] As the glycol component, ethylene glycol is the main component, but other glycol components can be used in combination as long as the properties are not impaired. As other glycol components, for example, one or more of alkylene glycols such as 1,4-butanediol, 1,3-propylene glycol, 1,2-propylene glycol, neopentylene glycol, hexamethylene glycol, decamethylene glycol, cyclohexanedimethanol, diethylene glycol, triethylene glycol, poly(oxy)ethylene glycol, poly(oxy)tetramethylene glycol, poly(oxy)methylene glycol, etc. may be used and can be arbitrarily selected according to the purpose. Further, a small amount of a polyhydric alcohol component such as glycerin may be used. Also, a small amount of an epoxy compound may be used. The usage amount of other glycol components is preferably 30 mol% or less, more preferably 20 mol% or less based on the total glycol components.

[0016] The above polyethylene naphthalate resin can be produced by a conventionally known production method. That is, it is produced by a direct esterification method in which a dicarboxylic acid component and a diol component are directly reacted to distill off water for esterification and then polycondensation is carried out under reduced pressure, or a transesterification method in which a dimethyl ester of a dicarboxylic acid and a diol component are reacted to distill off methyl alcohol for transesterification and then polycondensation is carried out under reduced pressure. Further, solid-phase polymerization can be carried out to increase the limiting viscosity number.

[0017] During the above transesterification reaction, esterification reaction, and polycondensation reaction, it is preferable to use a catalyst and a stabilizer. As the transesterification catalyst, Mg compounds, Mn compounds, Ca compounds, Zn compounds, etc. are used, and examples thereof include acetates, monocarboxylates, alcoholates, and oxides of these. Also, the esterification reaction can be carried out only with dicarboxylic acid and diol without adding a catalyst, but it can also be carried out in the presence of a polycondensation catalyst described later. As the polycondensation catalyst, Ge compounds, Ti compounds, Sb compounds, etc. can be used, and examples thereof include germanium dioxide, germanium hydroxide, germanium alcoholate, titanium tetrabutoxide, titanium tetraisopropoxide, and titanium oxalate. It is preferable to use a phosphorus compound as the stabilizer. Preferred phosphorus compounds include phosphoric acid and its esters, phosphorous acid and its esters, and hypophosphorous acid and its esters. Also, during the esterification reaction, a tertiary amine such as triethylamine, a quaternary ammonium hydroxide such as tetraethylammonium hydroxide, and a basic compound such as sodium carbonate can be added to suppress the by-production of diethylene glycol. In addition, various stabilizers and modifiers can be blended into the obtained polyester resin.

[0018] The intrinsic viscosity of component A is preferably 0.5 to 1.0 dl / g, more preferably 0.55 to 0.85 dl / g, and even more preferably 0.60 to 0.68 dl / g. If the intrinsic viscosity of component A is less than 0.5 dl / g, the mechanical properties may be inferior, and if it exceeds 1.0 dl / g, the viscosity of the polyethylene naphthalate resin may be too high and it may not be possible to take it out from the polymerization kiln.

[0019] <Component B> The resin composition of the present invention contains recycled carbon fibers to which a sizing agent is at least partially attached as component B. Recycled carbon fibers are, for example, carbon fibers recovered from the end materials of intermediate products such as prepregs generated from the manufacturing process of CFRP and used CFRP. Recycled carbon The method for recovering the elemental fibers can be manufactured by any method, but it is preferably a method of heating and removing only the matrix resin from CFRP by thermal decomposition. The fiber diameter of the recycled carbon fiber is not particularly limited, but is preferably 2 to 15 μm, more preferably 3 to 10 μm. Carbon fibers having an average fiber diameter within such a range may be able to exhibit good mechanical properties without impairing the appearance of the molded body.

[0020] It is necessary that at least a part of the sizing agent adheres to the B component of the present invention. When the sizing agent is not attached, the recycled carbon fiber is defibrated and the extrudability is significantly reduced. Examples of the sizing agent include polyester-based sizing agents, polyamide-based sizing agents, and epoxy-based sizing agents, but a polyester-based sizing agent is preferred.

[0021] The adhesion amount of the sizing agent is preferably 0.5 to 5.0% by weight, more preferably 1.0 to 3.0% by weight. If the adhesion amount of the sizing agent is less than 0.5% by weight, the productivity or the moldability may decrease, and if it exceeds 5.0% by weight, a large amount of mold deposits may occur.

[0022] The 5% weight loss temperature in the thermogravimetric-differential thermal analysis measurement when the temperature of the B component is raised from room temperature at a rate of 5 ° C. / min in air needs to be 460 ° C. or higher, preferably 470 ° C. or higher, and more preferably 475 ° C. or higher. If the 5% weight loss temperature is less than 460 ° C., a large amount of mold deposits will occur during injection molding. The upper limit of the 5% weight loss temperature is not particularly limited, but is preferably 500 ° C. or lower.

[0023] The content of the B component is 10 to 100 parts by weight, preferably 15 to 90 parts by weight, and more preferably 20 to 70 parts by weight with respect to 100 parts by weight of the A component. When the content is less than 10 parts by weight, the mechanical properties deteriorate, and when it exceeds 100 parts by weight, the extrudability deteriorates.

[0024] <Regarding the C component> The polyetherimide resin as Component C of the present invention is a resin containing a cyclic imide structure and is not particularly limited as long as it can be used for the purpose of the present invention. However, a polyetherimide resin containing an aliphatic or aromatic ether unit and a cyclic imide group as repeating units is preferred. Further, as long as the effects of the present invention are not inhibited, structural units other than cyclic imide and ether units, such as aromatic, aliphatic, aliphatic ester units, oxycarbonyl units, etc., may be contained in the main chain of the polyimide.

[0025] Specific examples of the polyetherimide resin that can be preferably used in the present invention include the polyetherimide resin represented by the following formula (1).

[0026]

Chemical formula

[0027] (In formula (1), R 1 is a divalent aromatic group containing 6 to 30 carbon atoms or an aliphatic group containing 4 or more carbon atoms, and R 2 is a divalent aromatic residue having 6 to 30 carbon atoms, an alkylene group having 2 to 20 carbon atoms, a cycloalkylene group having 2 to 20 carbon atoms, and a polydiorganosiloxane group chain-terminated with an alkylene group having 2 to 8 carbon atoms. It is a divalent organic group selected from the group consisting of, and n represents an integer of 2 or more. .) Examples of the above R 1 , R 2 include aromatic residues and alkylene groups represented by the following formulas (2) to (8).

[0028]

Chemical formula

[0029] (In formula (8), n represents an integer of 2 or more.) In the present invention, from the viewpoint of compatibility with polyethylene naphthalate resin, a polyetherimide resin represented by the following formula (9) is more preferable.

[0030]

Chemical formula

[0031] (In formula (9), n represents an integer of 2 or more.) Examples of this polyetherimide resin include "ULTEM 1010" manufactured by SHPP Japan Co., Ltd.

[0032] The content of component C is preferably 10 to 100 parts by weight, more preferably 20 to 90 parts by weight, and still more preferably 30 to 85 parts by weight with respect to 100 parts by weight of component A. When the content of component C is less than 10 parts by weight, the heat resistance may not be improved. On the other hand, when the content exceeds 100 parts by weight, the mechanical properties may decrease.

[0033] (Other components) In addition, the resin composition of the present invention can contain various additives such as an antioxidant and a release agent within a range not contrary to the gist of the present invention.

[0034] <Antioxidant> The resin composition of the present invention can contain at least one antioxidant selected from the group consisting of a hindered phenol-based compound, a phosphite-based compound, a phosphonite-based compound, and a thioether-based compound as an antioxidant. By blending an antioxidant, not only the hue and fluidity during molding processing are stabilized, but also the hydrolysis resistance is improved.

[0035] Examples of hindered phenolic compounds include α-tocopherol, butylhydroxytoluene, sinapyl alcohol, vitamin E, n-octadecyl-β-(4'-hydroxy-3',5'-di-tert-butylphenyl) propionate, 2-tert-butyl-6-(3'-tert-butyl-5'-methyl-2'-hydroxybenzyl)-4-methylphenyl acrylate, 2,6-di-tert-butyl-4-(N,N-dimethylaminomethyl)phenol, 3,5-di-tert-butyl-4-hydroxybenzyl phosphonate diethyl ester, 2,2'-methylenebis(4-methyl-6-tert-butylphenol), 2,2'-methylenebis(4-ethyl-6-tert-butylphenol), 4,4'-methylenebis(2,6-di-tert-butylphenol), 2,2'-methylenebis(4-methyl-6-cyclohexylphenol), 2,2'-dimethylene-bis(6-α-methyl-benzyl-p-cresol) 2,2'-ethylidene-bis(4,6-di-tert-butylphenol), 2,2'-butylidene-bis(4-methyl-6-tert-butylphenol), 4,4'-butylidenebis(3-methyl-6-tert-butylphenol), triethylene glycol-N-bis-3-(3-tert-butyl-4-hydroxy-5-methylphenyl) propionate, 1,6-hexanediol bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate], bis[2-tert-butyl-4-methyl 6-(3-tert-butyl-5-methyl-2-hydroxybenzyl) phenyl] terephthalate, 3,9-bis{2-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy]-1,1,-dimethylethyl}-2,4,8,10-tetraoxaspiro[5,5]undecane, 4,4'-thiobis(6-tert-butyl-m-cresol), 4,4'-thiobis(3-methyl-6-tert-butylphenol), 2,2'-thiobis(4-methyl-6-tert-butylphenol), bis(3,5-di-tert-butyl-4-hydroxybenzyl) sulfide, 4,4'-di-thiobis(2,6-di-tert-butylphenol), 4,4'-tri-thiobis(2,6-di-tert-butylphenol), 2,2-thiodiethylenebis-[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 2,4-bis(n-octylthio)-6-(4-hydroxy-3’,5’-di-tert-butylanilino)-1,3,5-triazine, N,N’-hexamethylenebis-(3,5-di-tert-butyl-4-hydroxyhydrocinnamide), N,N’-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hydrazine, 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, tris(3,5-di-tert-butyl-4-hydroxyphenyl)isocyanurate, tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanurate, 1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)isocyanurate, 1,3,5-tris2[3(3,5-di-tert-butyl-4-hydroxyphenyl)propionyloxy]ethylisocyanurate, and tetrakis[methylene-3-(3’,5’-di-tert-butyl-4-hydroxyphenyl)propionate]methane, etc. are exemplified. Among the above compounds, tetrakis[methylene-3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate]methane, octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, and 3,9-bis[2-{3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy}-1,1-dimethylethyl]-2,4,8,10-tetraoxaspiro[5,5]undecane are preferably used. Particularly, octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate is preferable. All of these are easily available. The above hindered phenol compounds can be used alone or in combination of two or more.,

[0036] Examples of phosphite compounds include triphenyl phosphite, tris(nonylphenyl) phosphite, tridecyl phosphite, trioctyl phosphite, trioctadecyl phosphite, didecyl monophenyl phosphite, dioctyl monophenyl phosphite, diisopropyl monophenyl phosphite, monobutyl diphenyl phosphite, monodecyl diphenyl phosphite, monooctyl diphenyl phosphite, tris(diethylphenyl) phosphite, tris(di-iso-propylphenyl) phosphite, tris(di-n-butylphenyl) phosphite, tris(2,4-di-tert-butylphenyl) phosphite, tris(2,6-di-tert-butylphenyl) phosphite, distearyl pentaerythritol diphosphite, bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite, bis(2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite, bis(2,6-di-tert-butyl-4-ethylphenyl) pentaerythritol diphosphite, bis{2,4-bis(1-methyl-1-phenylethyl)phenyl} pentaerythritol diphosphite, phenyl bisphenol A pentaerythritol diphosphite, bis(nonylphenyl) pentaerythritol diphosphite, and dicyclohexyl pentaerythritol diphosphite. Further examples of other phosphite compounds include those that react with divalent phenols and have a cyclic structure. For example, 2,2'-methylenebis(4,6-di-tert-butylphenyl)(2,4-di-tert-butylphenyl) phosphite, 2,2'-methylenebis(4,6-di-tert-butylphenyl)(2-tert-butyl-4-methylphenyl) phosphite, and 2,2-methylenebis(4,6-di-tert-butylphenyl) octyl phosphite.Suitable phosphite compounds are distearyl pentaerythritol diphosphite, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite, and bis{2,4-bis(1-methyl-1-phenylethyl)phenyl}pentaerythritol diphosphite.

[0037] Also, for example, 2,4,8,10-tetra-t-butyl-6-[3-(3-methyl-4-hydroxy-5-t-butylphenyl)propoxy]dibenzod[f][1,3,2]dioxaphosphepine [commercially available as "Sumilizer GP" (manufactured by Sumitomo Chemical Co., Ltd.)], 2,10-dimethyl-4,8-di-t-butyl-6-[3-(3,5-di-t-butyl-4-hydroxyphenyl)propoxy]-12H-dibenzod[g][1,3,2]dioxaphosphocin, 2,4,8,10-tetra-t-butyl-6-[3-(3,5-di-t-butyl-4-hydroxyphenyl)propoxy]dibenzod[f][1,3,2]dioxaphosphepine, 2,4,8,10-tetra-t-pentyl-6-[3-(3,5-di-t-butyl-4-hydroxyphenyl)propoxy]-12-methyl-12H-dibenzod[g][1,3,2]dioxaphosphocin, 2,10-dimethyl-4,8-di-t-butyl-6-[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionyloxy]-12H-dibenzod[g][1,3,2]dioxaphosphocin, 2,4,8,10-tetra-t-pentyl-6-[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionyloxy]-12-methyl-12H-dibenzod[g][1,3,2]dioxaphosphocin, 2,4,8,10-tetra-t-butyl-6-[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionyloxy]-dibenzod[f][1,3,2]dioxaphosphepine, 2,10-dimethyl-4,8-di-t-butyl-6-(3,5-di-t-butyl-4-hydroxybenzoyloxy)-12H-dibenzod[g][1,3,2]dioxaphosphocin, 2,4,8,10-tetra-t-butyl-6-(3,5-di-t-butyl-4-hydroxybenzoyloxy)-12-methyl-12H-dibenzod[g][1,3,2]dioxaphosphocin, 2,10-dimethyl-4,8-di-t-butyl-6-[3-(3-methyl-4-hydroxy-5-t-butylphenyl)propoxy]-12H-dibenzod[g][1,3,2]dioxaphosphocin, 2,4,8,10-tetra-t-butyl-6-[3-(3,5-di-t-butyl-4-hydroxyphenyl)propoxy]-12H-dibenzodg][1,3,2]dioxaphosphosin, 2,10 - diethyl - 4,8 - di - t - butyl - 6 - [3 - (3,5 - di - t - butyl - 4 - hydroxyphenyl)propoxy] - 12H - dibenzo[d,g][1,3,2]dioxaphosphosin, 2,4,8,10 - tetra - t - butyl - 6 - [2,2 - dimethyl - 3 - (3 - t - butyl - 4 - hydroxy - 5 - methylphenyl)propoxy] - dibenzo[d,f][1,3,2]dioxaphosphepine, etc. can be mentioned. All of these are easily available. The above phosphite - based compounds can be used alone or in combination of two or more kinds.,

[0038] Examples of phosphonite compounds include tetrakis(2,4-di-tert-butylphenyl)-4,4'-biphenylenediphosphonite, tetrakis(2,4-di-tert-butylphenyl)-4,3'-biphenylenediphosphonite, tetrakis(2,4-di-tert-butylphenyl)-3,3'-biphenylenediphosphonite, tetrakis(2,6-di-tert-butylphenyl)-4,4'-biphenylenediphosphonite, tetrakis(2,6-di-tert-butylphenyl)-4,3'-biphenylenediphosphonite, tetrakis(2,6-di-tert-butylphenyl)-3,3'-biphenylenediphosphonite, bis(2,4-di-tert-butylphenyl)-4-phenyl-phenylphosphonite, bis(2,4-di-tert-butylphenyl)-3-phenyl-phenylphosphonite, bis(2,6-di-n-butylphenyl)-3-phenyl-phenylphosphonite, bis(2,6-di-tert-butylphenyl)-4-phenyl-phenylphosphonite, bis(2,6-di-tert-butylphenyl)-3-phenyl-phenylphosphonite, and the like. Tetrakis(di-tert-butylphenyl)-biphenylenediphosphonite and bis(di-tert-butylphenyl)-phenyl-phenylphosphonite are preferred, and tetrakis(2,4-di-tert-butylphenyl)-biphenylenediphosphonite and bis(2,4-di-tert-butylphenyl)-phenyl-phenylphosphonite are more preferred. Such phosphonite compounds can be preferably used in combination with phosphite compounds having an aryl group substituted with two or more of the above alkyl groups. Tetrakis(2,4-di-tert-butylphenyl)-biphenylenediphosphonite is preferred as the phosphonite compound, and stabilizers mainly composed of the phosphonite are commercially available as Sandostab P-EPQ (trademark, manufactured by Clariant) and Irgafos P-EPQ (trademark, manufactured by CIBA SPECIALTY CHEMICALS), and either can be used. The above phosphonite compounds can be used alone or in combination of two or more.

[0039] Specific examples of the thioether compounds include dilauryl thiodipropionate, ditridecyl thiodipropionate, dimyristyl thiodipropionate, distearyl thiodipropionate, pentaerythritol - tetrakis(3 - laurylthiopropionate), pentaerythritol - tetrakis(3 - dodecylthiopropionate), pentaerythritol - tetrakis(3 - octadecylthiopropionate), pentaerythritol tetrakis(3 - myristylthiopropionate), pentaerythritol - tetrakis(3 - stearylthiopropionate), etc. The above - mentioned thioether compounds can be used alone or in combination of two or more.

[0040] The content of the antioxidant is preferably 0.01 to 2 parts by weight, more preferably 0.03 to 1 part by weight, and still more preferably 0.05 to 0.5 part by weight with respect to 100 parts by weight of Component A. When the content of the antioxidant is less than 0.01 part by weight, the antioxidant effect is insufficient, and not only the hue and fluidity during molding processing become unstable, but also the hydrolysis resistance may deteriorate. Also, when such content is more than 2 parts by weight, reaction components derived from the antioxidant may conversely deteriorate the hydrolysis resistance.

[0041] Moreover, it is preferable to use a combination of any two or more of the hindered phenol - type compound, phosphite - type compound, phosphonite - type compound, and thioether - type compound. By using a combination of any two or more of the hindered phenol - type compound, phosphite - type compound, phosphonite - type compound, and thioether - type compound, a synergistic effect as a stabilizer is exerted, which is effective in stabilizing the hue and fluidity during molding processing and improving the hydrolysis resistance.

[0042] <Release agent> The resin composition of the present invention can contain a release agent. Specific examples of the release agent include fatty acids, fatty acid metal salts, oxyfatty acids, paraffins, low molecular weight polyolefins, fatty acid amides, alkylene bisfatty acid amides, aliphatic ketones, partially saponified fatty acid esters, lower alcohol fatty acid esters, polyhydric alcohol fatty acid esters, polyglycol fatty acid esters, and modified silicones. By blending these, a molded article excellent in mechanical properties, moldability, and heat resistance can be obtained.

[0043] As the fatty acid, those having 6 to 40 carbon atoms are preferable, and specifically, oleic acid, stearic acid, lauric acid, hydroxystearic acid, behenic acid, arachidonic acid, linoleic acid, linolenic acid, ricinoleic acid, palmitic acid, montanic acid, and mixtures thereof can be mentioned. As the fatty acid metal salt, alkali (earth) metal salts of fatty acids having 6 to 40 carbon atoms are preferable, and specifically, calcium stearate, sodium montanate, calcium montanate, etc. can be mentioned.

[0044] Examples of the oxyfatty acid include 1,2-oxystearic acid. As the paraffin, those having 18 or more carbon atoms are preferable, and examples include liquid paraffin, natural paraffin, microcrystalline wax, and petrolactam.

[0045] As the low molecular weight polyolefin, those having a molecular weight of 5000 or less are preferable, and specifically, polyethylene wax, maleic acid-modified polyethylene wax, oxidized type polyethylene wax, chlorinated polyethylene wax, polypropylene wax, etc. can be mentioned.

[0046] As the fatty acid amide, those having 6 or more carbon atoms are preferable, and specifically, oleic acid amide, erucic acid amide, behenic acid amide, etc. can be mentioned.

[0047] As the alkylene bis fatty acid amide, those having 6 or more carbon atoms are preferred, and specifically, methylene bis stearic acid amide, ethylene bis stearic acid amide, N,N-bis(2-hydroxyethyl) stearic acid amide and the like can be mentioned.

[0048] As the aliphatic ketone, those having 6 or more carbon atoms are preferred, and higher aliphatic ketones and the like can be mentioned.

[0049] Examples of the partially saponified ester of fatty acid include partially saponified ester of montanic acid and the like. Examples of the lower alcohol ester of fatty acid include stearic acid ester, oleic acid ester, linoleic acid ester, linolenic acid ester, adipic acid ester, behenic acid ester, arachidonic acid ester, montanic acid ester, isostearic acid ester and the like.

[0050] Examples of the polyhydric alcohol ester of fatty acid include glycerol tristearate, glycerol distearate, glycerol monostearate, pentaerythritol tetrastearate, pentaerythritol tristearate, pentaerythritol dimyristate, pentaerythritol monostearate, pentaerythritol adipate stearate, sorbitan monobehenate and the like. Examples of the polyglycol ester of fatty acid include polyethylene glycol fatty acid ester, polytrimethylene glycol fatty acid ester, polypropylene glycol fatty acid ester and the like.

[0051] Examples of the modified silicone include polyether modified silicone, higher fatty acid alkoxy modified silicone, higher fatty acid-containing silicone, higher fatty acid ester modified silicone, methacryl modified silicone, fluorine modified silicone and the like.

[0052] Among them, fatty acids, fatty acid metal salts, oxy fatty acids, fatty acid esters, partially saponified fatty acid esters, paraffin, low molecular weight polyolefins, fatty acid amides, and alkylene bis fatty acid amides are preferred, and partially saponified fatty acid esters and alkylene bis fatty acid amides are more preferred. Among these, montanic acid esters, partially saponified montanic acid esters, polyethylene wax, acid value polyethylene wax, sorbitan fatty acid esters, erucic acid amide, and ethylene bis stearic acid amide are preferred, and particularly, partially saponified montanic acid esters and ethylene bis stearic acid amide are preferred.

[0053] The release agent may be used alone or in combination of two or more. The content of the release agent is preferably 0.01 to 3 parts by weight, more preferably 0.03 to 2 parts by weight, based on 100 parts by weight of Component A.

[0054] <Method for producing resin composition> To produce the resin composition of the present invention, any method can be adopted. For example, a method of preliminarily mixing each component and optionally other components, then melt-kneading and pelletizing can be mentioned. As means for preliminary mixing, a Nauta mixer, V-type blender, Henschel mixer, mechanochemical device, extrusion mixer, etc. can be mentioned. In preliminary mixing, granulation can also be performed by an extrusion granulator, briquetting machine, etc. in some cases. After preliminary mixing, melt-kneading is performed with a melt-kneading machine typified by a vented twin-screw extruder, and pelletizing is performed with a device such as a pelletizer. Other melt-kneading machines include a Banbury mixer, kneading rolls, a constant-temperature stirring vessel, etc., but a vented twin-screw extruder is preferred. Alternatively, a method of independently supplying each component and optionally other components to a melt-kneading machine typified by a twin-screw extruder without preliminary mixing can also be adopted.

[0055] <Regarding the molded body> The molded article made of the resin composition of the present invention can be obtained by molding the pellets produced as described above. Preferably, it can be obtained by injection molding or extrusion molding. In injection molding, not only ordinary molding methods but also injection compression molding, injection press molding, gas assist injection molding, foam molding (including the method of injecting supercritical fluid), insert molding, in-mold coating molding, adiabatic mold molding, rapid heating and cooling mold molding, two-color molding, multi-color molding, sandwich molding, and ultra-high speed injection molding can be mentioned. Also, either a cold runner system or a hot runner system can be selected for molding. In extrusion molding, it can also be used in the form of various profiled extruded articles, sheets, films, etc. Also, for the molding of sheets and films, methods such as inflation method, calender method, casting method, etc. can also be used. Furthermore, it is also possible to use the sheet-shaped molded article as a molded article having a specific shape by vacuum molding or press molding.

Examples

[0056] The present invention will be further described below with reference to examples. Unless otherwise specified, parts in the examples are parts by weight and % is % by weight. The evaluation was carried out by the following method.

[0057] [Evaluation of Resin Composition] (1) Extrudability The extrudability when creating pellets by the following method was evaluated according to the following criteria. 〇: The recycled carbon fiber can be supplied to the extruder without problems and can be continuously pelletized. △: The supply of the recycled carbon fiber is slightly unstable, but pelletization is possible. ×: The recycled carbon fiber cannot be stably supplied to the extruder and pelletization is impossible.

[0058] (2) Tensile fracture strength The pellets obtained by the following method were dried at 130 °C for 7 hours, and then test pieces were produced using an injection molding machine (EC130SXII-4Y manufactured by Toshiba Machine Co., Ltd.) at a cylinder temperature of 310 °C and a mold temperature of 80 °C. A tensile test was carried out according to ISO527-1 and 527-2 under the conditions of a temperature of 23 °C and a speed of 5 mm / min, and the tensile fracture strength was measured. The tensile fracture strength needs to be 120 MPa or more.

[0059] (3) Mold deposit The pellets obtained by the following method were dried at 130 °C for 7 hours, and then a molded body was continuously molded using an injection molding machine (PS40E5ASE manufactured by Nissei Plastic Industrial Co., Ltd.). After 200 shots, the degree of contamination of the mold gas vent part was visually evaluated according to the following criteria. The molding temperature was 310 °C and the mold temperature was 80 °C. 〇: The contaminated area is less than 25%. △: The contaminated area is 25% or more and less than 50%. ×: The contaminated area is 50% or more.

[0060] [Examples 1 to 15, Comparative Examples 1 to 4] According to the addition amounts shown in Table 1, the components excluding component B were supplied to the twin-screw extruder from the first supply port. Here, the first supply port refers to the supply port at the root of the twin-screw extruder. Component B was supplied from the second supply port using a side feeder. For the purpose of assisting the supply of component B to the twin-screw extruder, a part of component A was supplied from the second supply port using a side feeder. Extrusion was carried out using a vented twin-screw extruder with a diameter of 30 mmΦ (manufactured by Japan Steel Works, Ltd.: TEX30α-31.5BW-2V), and melt kneading was performed at a screw rotation speed of 200 rpm, a discharge rate of 16 kg / h, and a vent vacuum degree of 3 kPa to obtain pellets. The extrusion temperature was 310 °C.

[0061] In addition, the following materials were used in the examples and comparative examples of the present invention. <Component A> The A-1 to A-4 components were prepared by the method shown in the following production example. The intrinsic viscosity of the A-1 to A-4 components was determined by the following method.

[0062] (1) Method for measuring intrinsic viscosity For components A-1 to A-4, 0.6 g each was heated and melted in 50 ml of a mixed solvent of phenol / tetrachloroethane = 3 / 2 (weight ratio), then cooled to room temperature. The viscosity of the resulting solution was measured at a temperature of 35 °C using an Ostwald viscometer, and the intrinsic viscosity of the resin was determined from the viscosity data of the resulting solution.

[0063] [Production Example 1] 100 parts by weight of dimethyl naphthalenedicarboxylate and 60 parts by weight of ethylene glycol were subjected to a transesterification reaction in the presence of 0.010 parts by weight (10 mmol%) of cobalt acetate tetrahydrate and 0.030 parts by weight (30 mmol%) of manganese acetate tetrahydrate by a conventional method. After 20 minutes of methanol distillation, 0.012 parts by weight (10 mmol%) of antimony trioxide was added, and 0.020 parts by weight (50 mmol%) of orthophosphoric acid was added before the end of the transesterification reaction. Then, a polycondensation reaction was carried out at 295 °C under high vacuum to obtain a polyethylene naphthalate resin (A-1) with an intrinsic viscosity of 0.51 dl / g.

[0064] [Production Example 2] The polyethylene naphthalate resin (A-1) obtained in Production Example 1 was subjected to solid-phase polymerization at a temperature of 227 °C and a vacuum degree of 0.5 Torr for 8 hours to obtain a polyethylene naphthalate resin (A-2) with an intrinsic viscosity of 0.68 dl / g.

[0065] [Production Example 3] The polyethylene naphthalate resin (A-1) obtained in Production Example 1 was subjected to solid-phase polymerization at a temperature of 227 °C and a vacuum degree of 0.5 Torr for 24 hours to obtain a polyethylene naphthalate resin (A-3) with an intrinsic viscosity of 0.83 dl / g.

[0066] [Production Example 4] 92 parts by weight of dimethyl naphthalenedicarboxylate and 8 parts by weight of dimethyl terephthalate were subjected to a transesterification reaction with 60 parts by weight of ethylene glycol in the presence of 0.010 parts by weight (10 mmol%) of cobalt acetate tetrahydrate and 0.030 parts by weight (30 mmol%) of manganese acetate tetrahydrate according to a conventional method. After 20 minutes of methanol distillation, 0.012 parts by weight (10 mmol%) of antimony trioxide was added, and 0.020 parts by weight (50 mmol%) of orthophosphoric acid was added before the completion of the transesterification reaction. Then, a polycondensation reaction was carried out at 295 °C under high vacuum, and then solid-phase polymerization was carried out at 227 °C and a vacuum degree of 0.5 Torr for 8 hours to obtain a polyethylene naphthalate resin (A-4) with an intrinsic viscosity of 0.76 dl / g.

[0067] <Component B> B-1: Recycled carbon fiber (manufactured by Carbon Fiber Recycling Co., Ltd.: T8S103CD0R (product name), polyester-based sizing agent (adhesion amount: 2% by weight), 5% weight loss temperature 483 °C) B-2 (comparative example): Recycled carbon fiber (manufactured by Carbon Fiber Recycling Co., Ltd.: T8S103CD0E (product name), epoxy-based sizing agent (adhesion amount: 2% by weight), 5% weight loss temperature 457 °C) B-3 (comparative example): Recycled carbon fiber without a sizing agent produced by pyrolyzing CFRP (5% weight loss temperature 487 °C)

[0068] <Component C> C-1: Polyetherimide (ULTEM1010 (trade name) manufactured by SHPP Japan Co., Ltd.)

[0069] (Other components) Release agent - 1: Unister H476S (manufactured by NOF Corporation)

[0070] [Table 1]

[0071] [Table 2]

[0072] <Examples 1 to 15> Since it is a composition within the scope of the claims, a molded article excellent in extrudability and mechanical properties and having less mold deposit could be obtained. <Comparative Example 1> Since the content of Component B was less than the lower limit, the mechanical properties were poor. <Comparative Example 2> Since the content of Component B exceeded the upper limit, the extrudability was poor. <Comparative Example 3> Since Component B was recycled carbon fiber with a 5% weight loss temperature of less than 460°C, there was a lot of mold deposit. <Comparative Example 4> Since Component B was recycled carbon fiber not containing a sizing agent, the extrudability was poor.

Claims

1. A polyethylene naphthalate resin composition containing (A) 100 parts by weight of a polyethylene naphthalate resin (component A) and (B) 10 to 100 parts by weight of recycled carbon fibers (component B) to which a sizing agent is at least partially attached, wherein the 5% weight loss temperature in thermogravimetric-differential thermal analysis measurement when the temperature of component B is raised from room temperature at a rate of 5 °C / min in air is 460 °C or higher. The polyethylene naphthalate resin composition is characterized by this.

2. The polyethylene naphthalate resin composition according to claim 1, wherein the sizing agent attached to component B is a polyester-based sizing agent.

3. Component A is a polyethylene naphthalate resin comprising at least one selected from the group consisting of naphthalenedicarboxylic acid or its ester derivative having a dicarboxylic acid component of 80 to 100 mol% and 0 to 20 mol% of terephthalic acid, isophthalic acid and their ester derivatives, and the diol component is ethylene glycol. The polyethylene naphthalate resin composition according to claim 1 or 2 is characterized by this.

4. The polyethylene naphthalate resin composition according to claim 1 or 2, characterized by containing (C) 10 to 100 parts by weight of a polyetherimide resin (component C) with respect to 100 parts by weight of component A.

5. A molded article made of the polyethylene naphthalate resin composition according to claim 1 or 2.

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