Resin composition and molded article obtained by molding therefrom

Abstract

The present invention provides a resin composition that exhibits excellent conductivity, carbon black shedding prevention, and abrasion resistance, and that can maintain a high molecular weight after solidification extrusion molding, as well as a molded article formed therefrom. [Solution] A resin composition characterized by containing (A) 3 to 15 parts by weight of (B) conductive carbon black (component B) having a DBP oil absorption of 200 to 400 ml / 100 g, (C) aromatic carbodiimide compound (component C) and (D) 0.005 to 1 part by weight of phosphonic acid ester (component D) having an acid value of 0.01 to 0.30 mgKOH / g, per 100 parts by weight of polybutylene naphthalate resin (component A).

Description

[Technical Field]

[0001] The present invention relates to a resin composition that is excellent in conductivity, carbon black shedding prevention, and abrasion resistance, and that can maintain a high molecular weight after solidification extrusion molding, and to a molded article made therefrom. [Background technology]

[0002] Traditionally, thermoplastic polyester resins have been widely used in electrical and electronic components, home appliances, and automotive parts due to their excellent mechanical properties, low elution, and chemical resistance. Furthermore, their high surface hardness, excellent wear resistance, and cleanliness make them promising for use in sliding components such as rollers, guides, and rails in the semiconductor industry.

[0003] Because sliding components come in a variety of shapes and thicknesses, in addition to the economically efficient injection molding method, solidification extrusion molding is used to create round bars and thick-walled plates, which are then machined to achieve the desired product shape. Solidification extrusion molding has a longer molten residence time compared to other molding methods, which can easily lead to a decrease in the molecular weight of the resin. This decrease in molecular weight can cause cracking and chipping during molding and machining, so a resin material that can maintain a high molecular weight after solidification extrusion molding is required. In addition, resin materials used in semiconductor manufacturing processes need to be made conductive. Resin materials without special formulations are insulating, and the discharge of charged static electricity can cause device damage. Carbon black is widely used as a conductive material because it is cost-effective and can impart uniform conductivity to resin materials, but when the resin material comes into contact with wafers or other components, the carbon black on the surface may fall off, which can contribute to a decrease in the cleanliness of the semiconductor process. Furthermore, resin materials with added carbon black generally become brittle, which impairs the wear resistance of the material.

[0004] Patent documents 1 and 2 disclose polyester resin compositions consisting of polyester resin, carbon black, and glass fibers, but their molecular weight is too low for use in solidification extrusion molding, and there is no mention of carbon black shedding prevention or abrasion resistance. Patent document 3 discloses a resin composition consisting of thermoplastic polyester resin, aromatic polycarbonate, and carbon black, but there is no mention of molecular weight or abrasion resistance after solidification extrusion molding. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2-272056 [Patent Document 2] Japanese Patent Publication No. 2000-302954 [Patent Document 3] Japanese Patent Publication No. 2010-254781 [Overview of the project] [Problems that the invention aims to solve]

[0006] The object of the present invention is to provide a resin composition that is excellent in conductivity, carbon black shedding prevention and wear resistance, and that can maintain a high molecular weight after solidification extrusion molding, as well as a molded article made therefrom. [Means for solving the problem]

[0007] The inventors of the present invention conducted extensive research to solve the above-mentioned problems and, as a result, discovered that the above objectives can be achieved by blending polybutylene naphthalate resin, conductive carbon black, aromatic carbodiimide compounds, and specific phosphonic acid esters in specific proportions, leading to the present invention.

[0008] In other words, the present invention is as follows. 1. A resin composition characterized by containing, per 100 parts by weight of (A) polybutylene naphthalate resin (component A), 3 to 15 parts by weight of (B) conductive carbon black (component B) having a DBP oil absorption of 200 to 400 ml / 100 g, (C) aromatic carbodiimide compound (component C) 0.05 to 2 parts by weight, and (D) phosphonic acid ester (component D) having an acid value of 0.01 to 0.30 mg KOH / g. 2. The resin composition according to item 1 above, characterized in that component C is an aromatic carbodiimide compound having a 5% weight loss temperature of 330°C or higher. 3. The resin composition according to item 1 or 2 above, characterized in that component C is a cyclic carbodiimide compound represented by the following formula (1).

[0009] [ka]

[0010] (In formula (1), X is a tetravalent group represented by formula (2) below, Ar 1 ~Ar 4 Each of these is independently an orthophenylene group or a 1,2-naphthalene-diyl group, which may be substituted with an alkyl group or phenyl group having 1 to 6 carbon atoms.

[0011] [ka]

[0012] 4. The resin composition according to any one of items 1 to 3 above, characterized in that component A is a polybutylene naphthalate resin having an intrinsic viscosity of 0.95 to 1.50 dl / g. 5. A resin composition according to any one of items 1 to 4 above, used for solidification extrusion molding. 6. A molded article obtained by molding any of the resin compositions described in item 1 to 5 above. [Effects of the Invention]

[0013] According to the present invention, there can be provided a resin composition excellent in conductivity, prevention of carbon black dropout, and abrasion resistance, capable of retaining a high molecular weight after solidification extrusion molding, and a molded article formed by molding the same. The molded article obtained from the resin composition of the present invention can be suitably used, for example, for mechanical element parts, sliding members, gears, bearings, rollers, rails, guides, retainers, housings, covers, cams, links, ball screw members, racks, motor parts, transfer pallets, housings, and wafer cases used in the fields of electric and electronic, semiconductor, automobile, industrial machinery, food, OA equipment, and architecture.

Embodiments for Carrying out the Invention

[0014] Hereinafter, the details of the present invention will be further described.

[0015] <Regarding Component A> The polybutylene naphthalate resin which is Component A of the present invention can be produced using a dicarboxylic acid component mainly composed of naphthalenedicarboxylic acid and / or an ester-forming derivative of naphthalenedicarboxylic acid, and a glycol component mainly composed of 1,4-butanediol. When a resin other than the polybutylene naphthalate resin is used as Component A, the abrasion resistance and the prevention of carbon black dropout decrease.

[0016] The naphthalenedicarboxylic acid components are mainly 2,6-naphthalenedicarboxylic acid and 2,7-naphthalenedicarboxylic acid, but other dicarboxylic acids can be used in combination as long as they do not impair the properties. Examples of other dicarboxylic acids include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, 4,4′-diphenyldicarboxylic acid, diphenoxyethane-4,4′-dicarboxylic acid, diphenylsulfone-4,4′-dicarboxylic acid, and diphenyl ether-4,4′-dicarboxylic acid, as well as aliphatic dicarboxylic acids such as adipic acid, sebacic acid, succinic acid, and oxalic acid, and alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid. One or more of these may be used, and can be arbitrarily selected depending on the purpose. The amount of other dicarboxylic acids used is preferably 30 mol% or less, more preferably 20 mol% or less, relative to the total acid component. The main components of the ester-forming derivatives of naphthalenedicarboxylic acid are dimethyl 2,6-naphthalenedicarboxylic acid and dimethyl 2,7-naphthalenedicarboxylic acid, but other ester-forming derivatives of dicarboxylic acids can be used in combination as long as the properties are not impaired. Examples of other ester-forming derivatives of dicarboxylic acids include lower dialkyl esters of aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, 4,4′-diphenyldicarboxylic acid, diphenoxyethane-4,4′-dicarboxylic acid, diphenylsulfone-4,4′-dicarboxylic acid, and diphenyl ether-4,4′-dicarboxylic acid, lower dialkyl esters of alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid, and lower dialkyl esters of aliphatic dicarboxylic acids such as adipic acid, sebacic acid, succinic acid, and oxalic acid. One or more of these may be used, and can be arbitrarily selected depending on the purpose. The amount of other ester-forming derivatives of dicarboxylic acids used is preferably 30 mol% or less, more preferably 20 mol% or less, relative to the total ester-forming derivative component of dicarboxylic acid.

[0017] Furthermore, small amounts of trifunctional or higher dicarboxylic acid components such as trimellitic acid may be used, as may small amounts of acid anhydrides such as trimellitic anhydride. In addition, small amounts of hydroxycarboxylic acids such as lactic acid and glycolic acid, or their alkyl esters, may be used, and these can be arbitrarily selected depending on the purpose.

[0018] The glycol component is primarily 1,4-butanediol, but other glycol components can be used in combination as long as they do not impair the properties. Other glycol components may include, for example, one or more alkylene glycols such as ethylene glycol, 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, and poly(oxy)methylene glycol, which can be arbitrarily selected depending on the purpose. Furthermore, a small amount of polyhydric alcohol component such as glycerin may be used. A small amount of epoxy compound may also be used. The amount of other glycol components used is preferably 30 mol% or less, more preferably 20 mol% or less, relative to the total glycol components.

[0019] The amount of glycol component used is preferably 1.1 to 1.4 molar times the amount of the dicarboxylic acid or the esterifying derivative of the dicarboxylic acid. If the amount of glycol component used is less than 1.1 molar times, the esterification or transesterification reaction may not proceed sufficiently, which is undesirable. Also, if it exceeds 1.4 molar times, although the reason is unclear, the reaction rate may slow down, and the amount of by-products such as tetrahydrofuran from the excess glycol component may increase, which is also undesirable.

[0020] In the production of polybutylene naphthalate resin, a titanium compound is used as a polymerization catalyst. Tetraalkyl titanates are preferred as the titanium compounds used as polymerization catalysts. Specifically, examples include tetra-n-propyl titanate, tetraisopropyl titanate, tetra-n-butyl titanate, tetra-sec-butyl titanate, tetra-t-butyl titanate, tetra-n-hexyl titanate, tetracyclohexyl titanate, tetraphenyl titanate, and tetrabenzyl titanate. These may also be used as a mixture of titanates. Of these titanium compounds, tetra-n-propyl titanate, tetraisopropyl titanate, and tetra-n-butyl titanate are particularly preferred, with tetra-n-butyl titanate being the most preferred. The amount of titanium compound added is preferably 10 ppm to 60 ppm, and more preferably 15 ppm to 30 ppm, as the titanium atom content in the resulting polybutylene naphthalate resin. If the titanium atom content in the generated polybutylene naphthalate resin exceeds 60 ppm, it is undesirable because the color tone and thermal stability of the resin composition of the present invention may decrease. On the other hand, if the titanium atom content is less than 10 ppm, good polymerization activity cannot be obtained, and it may not be possible to obtain a polybutylene naphthalate resin with sufficiently high intrinsic viscosity, which is also undesirable.

[0021] The polybutylene naphthalate resin of the present invention is preferably produced via an esterification or transesterification reaction step of a dicarboxylic acid component mainly composed of naphthalenedicarboxylic acid and / or its ester-forming derivative and a glycol component mainly composed of 1,4-butanediol in the presence of a titanium compound, followed by a polycondensation reaction step. The temperature at the end of the esterification or transesterification reaction is preferably in the range of 180°C or higher and 220°C or lower, more preferably 180°C or higher and 210°C or lower. When the temperature at the end of the esterification reaction or transesterification reaction exceeds 220°C, the reaction rate increases, but the amount of by-products such as tetrahydrofuran may increase, which is not preferable. Also, when it is less than 180°C, the reaction may not proceed. The reaction product (bis glycol ether and / or its low polymer) obtained by the esterification or transesterification reaction is preferably polycondensed under a reduced pressure of 0.4 kPa (3 Torr) or less at a temperature not lower than the melting point of the polybutylene naphthalate resin and not higher than 270°C. When the polycondensation reaction temperature exceeds 270°C, rather, the reaction rate decreases and coloring may increase, which is not preferable.

[0022] The intrinsic viscosity of the polybutylene naphthalate resin measured at 35°C in orthochlorophenol is preferably 0.95 to 1.50 dl / g, more preferably 0.98 to 1.40 dl / g, and even more preferably 1.00 to 1.30 dl / g. When the intrinsic viscosity is less than 0.95 dl / g, the abrasion resistance may deteriorate and the molecular weight after solidification extrusion molding may decrease. When it exceeds 1.50 dl / g, the dispersion of conductive carbon black may become difficult and the strand take-up property may deteriorate.

[0023] <Regarding Component B> The conductive carbon black, which is component B of the present invention, is used to impart conductivity to the resin composition, and any known conductive carbon black can be used. The conductive carbon black is not limited by its raw materials or manufacturing method, and any carbon black such as Ketjen black, acetylene black, furnace black, or thermal black can be used, but among these, furnace black is preferred because it is cost-effective and relatively easy to disperse in polybutylene naphthalate resin.

[0024] The DBP oil absorption of conductive carbon black is 200 to 400 ml / 100g, preferably 250 to 380 ml / 100g, and more preferably 300 to 350 ml / 100g. By using conductive carbon black with a DBP oil absorption within this range, good conductivity and wear resistance can be achieved simultaneously. Here, DBP oil absorption is a value measured by a dibutyl phthalate absorbmeter, representing the volume of dibutyl phthalate contained in 100g of conductive carbon black in milliliters. It indicates the degree of structure of the conductive carbon black and is said to affect the conductivity when blended into a resin composition. If the DBP oil absorption is less than 200 ml / 100g, conductivity deteriorates. Furthermore, if the DBP oil absorption exceeds 400 ml / 100g, the carbon black does not disperse when the polybutylene naphthalate resin and conductive carbon black are melt-kneaded, leading to frequent strand drawdown and making continuous extrusion difficult.

[0025] The BET specific surface area of ​​conductive carbon black is 1000 m². 2 Materials with a BET specific surface area of ​​1000 m² or more are preferably used. 2 Conductivity may decrease below / g. While there are no specific upper limits on the BET specific surface area, 1500m is recommended as it may significantly impair workability. 2 It is preferable that the value be less than or equal to / g. Here, the BET specific surface area is a value obtained by the liquid nitrogen adsorption method and represents the surface area per unit weight of conductive carbon black.

[0026] The content of Component B is 3 to 15 parts by weight, preferably 5 to 13 parts by weight, more preferably 6 to 12 parts by weight with respect to 100 parts by weight of Component A. When the content is less than 3 parts by weight, the conductivity deteriorates. When it exceeds 15 parts by weight, carbon black does not disperse during the melt kneading of polybutylene naphthalate resin and conductive carbon black, and strand draw-down frequently occurs, making continuous extrusion difficult.

[0027] <Regarding Component C> The resin composition of the present invention contains an aromatic carbodiimide compound as Component C. When Component C is a carbodiimide compound other than aromatic, the abrasion resistance and the prevention of carbon black dropout deteriorate, and the molecular weight after solidification extrusion molding decreases.

[0028] The aromatic carbodiimide compound refers to a compound having at least one carbodiimide group (-N = C = N-) and at least one aromatic ring in the molecule, and those known per se can be used. At least one aromatic carbodiimide compound selected from the group consisting of compounds having two or more carbodiimide groups is preferable, and at least one aromatic carbodiimide compound selected from the group consisting of compounds having two carbodiimide groups is more preferable. When there are two carbodiimide groups, the molecular weight of the resin composition may be improved by connecting polyester molecular chains to both ends of the carbodiimide group.

[0029] The 5% weight loss temperature of the aromatic carbodiimide compound is preferably 330°C or higher, more preferably 350°C or higher, and even more preferably 370°C or higher. If the 5% weight loss temperature is below 330°C, the molecular weight after solidification extrusion molding may decrease. The reason for this is not clear, but it is presumed that the decomposition of the polybutylene naphthalate resin is accelerated by decomposition products or radicals generated by the decomposition of the carbodiimide compound that remains at high temperatures. The 5% weight loss temperature referred to here is the temperature at which the weight has decreased by 5% from the weight at the start of measurement when the temperature is raised from room temperature at a rate of 20°C / min under nitrogen purge using a differential thermobalance (TGA). There is no particular upper limit to the 5% weight loss temperature, but it is preferably 500°C. Specific examples of aromatic carbodiimide compounds with a 5% weight loss temperature of 330°C or higher include cyclic carbodiimide compounds. Their cyclic nature can improve heat resistance, and the generation of isocyanate gases can be suppressed, resulting in a better working environment.

[0030] Cyclic carbodiimide compounds have a cyclic structure. The cyclic structure has at least one carbodiimide group (-N=C=N-), with the first and second nitrogen atoms linked by a bonding group. Each cyclic structure contains only one carbodiimide group. The molecular weight of cyclic carbodiimide compounds is preferably 100 to 1,000. If the molecular weight is less than 100, structural stability and volatility of the cyclic carbodiimide compound may become problematic. If the molecular weight is greater than 1,000, the production of cyclic carbodiimide may require synthesis in a dilution system or result in a decrease in yield, which can be problematic from a cost perspective. From this viewpoint, the molecular weight is more preferably 100 to 750, and even more preferably 250 to 750. Among such cyclic carbodiimide compounds, the compound represented by the following formula (1) can be preferably used from the viewpoint of reactivity.

[0031] [ka]

[0032] (In formula (1), X is a tetravalent group represented by formula (2) below, Ar 1 ~Ar 4 Each of these is independently an orthophenylene group or a 1,2-naphthalene-diyl group, which may be substituted with an alkyl group or phenyl group having 1 to 6 carbon atoms.

[0033] [ka]

[0034] Examples of alkyl groups having 1 to 6 carbon atoms include methyl, ethyl, propyl, butyl, pentyl, and hexyl groups. The following compounds are specific examples of cyclic carbodiimide compounds.

[0035] [ka]

[0036] [ka]

[0037] [ka]

[0038] These cyclic carbodiimide compounds can be produced by methods well known from various documents and patent publications (for example, the method described in International Publication WO10 / 071213).

[0039] The content of Component C is 0.05 to 2 parts by weight, preferably 0.05 to 1 part by weight, more preferably 0.08 to 0.6 parts by weight, based on 100 parts by weight of Component A. When the content is less than 0.05 parts by weight, the abrasion resistance and the prevention of carbon black dropout deteriorate, and the molecular weight after solidification extrusion molding decreases. When it exceeds 2 parts by weight, coarse gel-like substances are generated during kneading, the strands crack, and continuous extrusion becomes difficult.

[0040] <Regarding Component D> For the phosphonate ester which is Component D of the present invention, those known per se can be used. By containing the phosphonate ester in the resin composition, the abrasion resistance is improved, and a high molecular weight can be maintained after solidification extrusion molding.

[0041] Specific examples of the above phosphonate ester include dimethyl methylphosphonate, diethyl methylphosphonate, dimethyl ethylphosphonate, diethyl ethylphosphonate, dimethyl phenylphosphonate, diethyl phenylphosphonate, diphenyl phenylphosphonate, dimethyl benzylphosphonate, diethyl benzylphosphonate, diphenyl benzylphosphonate, lithium (ethyl 3,5 - di - tert - butyl - 4 - hydroxybenzylphosphonate), sodium (ethyl 3,5 - di - tert - butyl - 4 - hydroxybenzylphosphonate), magnesium bis(ethyl 3,5 - di - tert - butyl - 4 - hydroxybenzylphosphonate), calcium bis(ethyl 3,5 - di - tert - butyl - 4 - hydroxybenzylphosphonate), diethyl phosphonoacetic acid, methyl diethyl phosphonoacetate, ethyl diethyl phosphonoacetate, etc. Among them, ethyl diethyl phosphonoacetate is preferred.

[0042] The acid value of the phosphonate ester is 0.01 to 0.30 mgKOH / g, preferably 0.01 to 0.20 mgKOH / g, more preferably 0.05 to 0.15 mgKOH / g. Those with an acid value less than 0.01 mgKOH / g are not practical in production, and when the acid value is greater than 0.30 mgKOH / g, the molecular weight after solidification extrusion molding decreases.

[0043] The content of component D is 0.005 to 1 part by weight, preferably 0.01 to 0.6 parts by weight, and more preferably 0.02 to 0.3 parts by weight, per 100 parts by weight of component A. If the content is less than 0.005 parts by weight, the abrasion resistance deteriorates and the molecular weight after extrusion decreases, and if it exceeds 1 part by weight, the abrasion resistance deteriorates.

[0044] <Other ingredients> The resin composition of the present invention may, to the extent that it does not contradict the spirit of the present invention, contain thermoplastic resins other than component A, and may optionally contain various additives such as antioxidants, impact modifiers, plasticizers, organic and inorganic fillers, flame retardants, colorants, light stabilizers, heat stabilizers other than component D, antistatic agents, antiblocking agents, lubricants, dispersants, flow modifiers, crystal nucleating agents, and conductive materials other than component B.

[0045] <Method for producing resin compositions> Any method can be used to produce the resin composition of the present invention. For example, one method involves pre-mixing each component, and optionally other components, then melt-kneading and pelletizing them. Means of pre-mixing include a Nauter mixer, a V-type blender, a Henschel mixer, a mechanochemical device, and an extruder mixer. Granulation may also be performed during pre-mixing using an extruder granulator or a briquetting machine. After pre-mixing, the mixture is melt-kneaded in a melt-kneader, such as a vented twin-screw extruder, and then pelletized using equipment such as a pelletizer. Other melt-kneaders include a Banbury mixer, kneading rolls, and a constant-temperature stirring vessel, but a vented twin-screw extruder is preferred. Alternatively, each component, and optionally other components, can be supplied independently to a melt-kneader, such as a twin-screw extruder, without pre-mixing.

[0046] <About molded products> The molded product made of the resin composition of the present invention can be obtained by molding the pellets produced as described above, and is preferably a molded product obtained by injection molding or solidification extrusion molding, and more preferably a molded product obtained by solidification extrusion molding. As injection molding, not only ordinary molding methods but also injection compression molding, injection press molding, gas-assisted 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. As solidification extrusion molding, methods such as obtaining a molded product by solidification extrusion molding a round bar and then cutting it into a disk shape, and obtaining a molded product by solidification extrusion molding a thick sheet and then punching it into a predetermined shape can be mentioned.

Examples

[0047] Hereinafter, the embodiments of the present invention will be described by way of examples, but the present invention is not limited thereto. Also, the evaluation of various physical properties was carried out by the following methods.

[0048] [Evaluation of Resin Composition] (1) Conductivity Evaluation (Surface Resistivity) After drying the pellets obtained by the following method at 120 °C for 6 hours, they were supplied to a single-screw extruder with a diameter of 20 mm, and a round bar with a diameter of 60 mm was continuously extruded under the conditions of a discharge rate of 200 - 300 mm / hr and an extrusion temperature of 270 °C, and then cut every 5 mm to obtain disk-shaped test pieces. Using these test pieces, measurement was carried out using a resistivity meter suitable for each resistance value. That is, when it is 10 9 Ω / sq or more, Hirester UP MCP-HT450 manufactured by Mitsubishi Chemical Corporation (applied voltage 10V, URSS probe), 10 8For values ​​less than Ω / sq, a Mitsubishi Chemical Corporation Loresta GP MCP-T600 (maximum voltage 90V, ESP probe (compliant with JIS K7194)) was used. Specifically, the surface resistivity of the central part of the surface of the molded product was measured using the resistivity meter described above under conditions of 23°C and 50% RH. The average value obtained from three test pieces was used as the conductivity of the composition. 9 It must be less than or equal to Ω / sq.

[0049] (2) Evaluation of carbon black's ability to prevent shedding The pellets obtained by the method described below were dried at 120°C for 6 hours, and then injection molded using an injection molding machine (EC130SXII-4Y, manufactured by Toshiba Machine Co., Ltd.) under conditions of cylinder temperature 280°C and mold temperature 120°C to obtain pin-shaped test specimens with a diameter of 5 mm at the end. Using a reciprocating friction tester (Tribogear TYPE-40, manufactured by Shinto Kagaku Co., Ltd.), the test specimens were subjected to reciprocating friction by pressing the pins against a base sheet under conditions of load 100 g, speed 10 mm / s, and 10 reciprocations. The density of the carbon residue adhering to the base sheet was visually evaluated on a 5-point scale as described below, and the average value obtained from the three test specimens was used as the carbon black fall-off prevention property of the composition. The density of the carbon residue must be 3 or less. 1: The carbon transfer cannot be visually confirmed. 2: The carbon transfer is fainter than the mark left when using a pencil hardness tester (No. 553-M, manufactured by Yasuda Seiki Seisakusho Co., Ltd.) to press a 9H pencil onto a base at a 45° angle and slide it once at a load of 50g and a speed of 30mm / min. 3: The carbon transfer is of the same darkness as the mark left when a 6-8H pencil is used and slid across the surface once under the same conditions as described above. 4. The carbon transfer is of the same darkness as the mark left when a 3-5H pencil is used and slid across the surface once under the same conditions as described above. 5: The carbon transfer is darker than the mark left when using a 2H pencil and sliding it once under the same conditions as above.

[0050] (3) Abrasion resistance evaluation (depth of wear) The pellets obtained by the method described below were dried at 120°C for 6 hours and then supplied to a 20 mm diameter single-screw extruder. A 60 mm diameter round bar was continuously extruded at a discharge rate of 200-300 mm / hr and an extrusion temperature of 270°C. The extruded bar was then cut into 5 mm lengths to obtain disc-shaped test pieces. Using these test pieces, a sliding test was performed using a reciprocating friction tester (Tribogear TYPE-40, manufactured by Shinto Kagaku Co., Ltd.) at a surface pressure of 140 MPa, a speed of 100 mm / s, and 7,000 reciprocations, with a 3 mm diameter SUJ2 metal ball as the indenter. After the test, the cross-sectional curve of the sliding surface was measured in a direction perpendicular to the sliding direction using a surface roughness shape measuring instrument (SURFCOM NEX001 SD2-12, manufactured by Tokyo Seimitsu Co., Ltd.) to determine the depth of wear caused by the sliding test. The test was performed three times, and the average value was taken as the wear resistance of the composition. A wear depth of 7 μm or less is required.

[0051] (4) Evaluation of molecular weight retention after solidification extrusion molding (intrinsic viscosity after solidification extrusion molding) The pellets obtained by the method described below were dried at 120°C for 6 hours and then supplied to a 20 mm diameter single-screw extruder. A 60 mm diameter round bar was continuously extruded at a discharge rate of 200-300 mm / hr and an extrusion temperature of 270°C. The bar was then cut into 5 mm lengths to obtain disc-shaped test pieces. These test pieces were finely chopped, dissolved in o-chlorophenol solvent, and centrifuged at 23,000 rpm for 1.5 hours. A calibration curve was created from the solution viscosity of the supernatant liquid of the solvent measured at a temperature of 30°C using an Ubbelohde viscosity tube, and the intrinsic viscosity was calculated. An intrinsic viscosity of 0.72 dl / g or higher is required.

[0052] [Examples 1-9, Comparative Examples 1-10] Components A to D were supplied separately to the twin-screw extruder from the first supply port according to the amounts shown in Table 1. Here, the first supply port refers to the supply port at the base. Extrusion was performed using a 30 mm diameter vented twin-screw extruder (manufactured by Japan Steel Works Ltd.: TEX30α-31.5BW-2V), with a discharge rate of 20 kg / h, an extrusion temperature of 280 °C, and a vent vacuum of 3 kPa, by melt-mixing to obtain pellets.

[0053] The above evaluation was carried out using the pellets. The results are shown in Table 1. (Component A) A-1: Polybutylene naphthalate resin obtained in Production Example I <Manufacturing example I> 315.0 parts of dimethyl 2,6-naphthalenedicarboxylic acid, 200.0 parts of 1,4-butanediol, and 0.062 parts of tetra-n-butyl titanate were placed in a transesterification reaction vessel, and the transesterification reaction was carried out for 150 minutes while raising the temperature of the transesterification reaction vessel to 210°C. The resulting reaction product was then transferred to a polycondensation reaction vessel and the polycondensation reaction was started. The polycondensation reaction was carried out by gradually reducing the pressure inside the polycondensation reaction vessel from atmospheric pressure to below 0.13 kPa (1 torr) over 40 minutes, while simultaneously raising the temperature to a predetermined reaction temperature of 260°C. Thereafter, the polycondensation reaction was carried out for 140 minutes while maintaining the reaction temperature at 260°C and the pressure at 0.13 kPa (1 torr). After 140 minutes, the polycondensation reaction was terminated, and the polybutylene naphthalate resin was extracted in strand form and cut into chips using a cutter while being cooled with water. Next, the obtained polybutylene naphthalate resin was subjected to solid-phase polymerization at a temperature of 213°C and a pressure of 0.13 kPa (1 Torr) or less for 8 hours to obtain a polybutylene naphthalate resin with an intrinsic viscosity of 1.05 dl / g. A-2: Polybutylene naphthalate resin obtained in Production Example II <Manufacturing example II> Except for setting the solid-phase polymerization temperature to 205°C, the polymerization reaction was carried out in the same manner as in Production Example I to obtain a polybutylene naphthalate resin with an intrinsic viscosity of 0.94 dl / g. (B component) B-1: Conductive carbon black manufactured by furnace process (DBP oil absorption 330 ml / 100 g, primary particle size 15-20 nm) B-2: Conductive carbon black manufactured by furnace process (DBP oil absorption capacity 360 ml / 100 g, primary particle size 30-40 nm) B-3 (Comparative Example): Conductive carbon black (manufactured by Lion Specialty Chemicals Co., Ltd., Ketjenblack EC600JD (product name), DBP oil absorption capacity 495 ml / 100 g, primary particle size 34 nm) B-4 (Comparative Example): Conductive carbon black manufactured by furnace process (DBP oil absorption 175 ml / 100 g, primary particle size 30-40 nm) (C component) C-1: Cyclic carbodiimide compound obtained in Production Example III The values ​​in the manufacturing examples were determined using the following method. (1) Identification of cyclic carbodiimide structures by NMR Identification by NMR was performed using a JNREX270 manufactured by JEOL Ltd. 1 H-NMR and 13 This was confirmed by 1C-NMR. Deuterated chloroform was used as the solvent. (2) Identification of the carbodiimide skeleton by IR The carbodiimide skeleton was identified using a Magna-750 from Nicolet Co., Ltd., and FT-IR was used to determine the characteristic 2100-2200 cm⁻¹ of carbodiimide. -1 This was done by confirming the absorption peak. (3) Measurement of the 5% weight loss temperature of carbodiimide compounds Using a Rigaku TG8121, 10 mg of a carbodiimide compound was heated from room temperature at a rate of 20°C / min under nitrogen purging, and the temperature at which the weight decreased by 5% relative to the weight at the start of the measurement was determined.

[0054] <Production example III> o-nitrophenol (0.11 mol), pentaerythrityltetrabromide (0.025 mol), potassium carbonate (0.33 mol), and 200 ml of N,N-dimethylformamide were charged into a reaction vessel equipped with a stirrer and heater under an N-2 atmosphere. After reacting at 130°C for 12 hours, DMF was removed by reduced pressure, and the resulting solid was dissolved in 200 ml of dichloromethane and diluted three times with 100 ml of water. The organic layer was dehydrated with 5 g of sodium sulfate, and dichloromethane was removed by reduced pressure to obtain intermediate product F (nitro compound). Next, intermediate product F (0.1 mol), 5% palladium carbon (Pd / C) (2 g), and 400 ml of ethanol / dichloromethane (70 / 30) were charged into a reaction vessel equipped with a stirrer, hydrogen purging was performed five times, and the reaction was carried out at 25°C with a constant supply of hydrogen. The reaction was terminated when the hydrogen level stopped decreasing. After recovering Pd / C and removing the mixed solvent, intermediate product G (amine) was obtained. Next, in a reaction apparatus equipped with a stirrer, heater, and dropping funnel, triphenylphosphine dibromide (0.11 mol) and 150 ml of 1,2-dichloroethane were charged under an N2 atmosphere and stirred. A solution of intermediate product G (0.025 mol) and triethylamine (0.25 mol) dissolved in 50 ml of 1,2-dichloroethane was gradually added dropwise at 25°C. After the addition was complete, the reaction was carried out at 70°C for 5 hours. The reaction solution was then filtered, and the filtrate was divided into 5 liquid-liquid steps with 100 ml of water each. The organic layer was dehydrated with 5 g of sodium sulfate, and 1,2-dichloroethane was removed under reduced pressure to obtain intermediate product H (triphenylphosphine). Next, in a reaction apparatus equipped with a stirrer and a dropping funnel, 0.11 mol of di-tert-butyl dicarbonate, 0.055 mol of N,N-dimethyl-4-aminopyridine, and 150 ml of dichloromethane were charged under an N2 atmosphere and stirred. 100 ml of dichloromethane in which the intermediate product H (0.025 mol) was dissolved at 25°C was slowly added dropwise. The reaction was allowed to proceed for 12 hours after addition. After removing the dichloromethane, the resulting solid was purified to obtain component C-1, represented by the following formula. The structure of component C-1 was confirmed by NMR and IR. The 5% weight loss temperature of component C-1 was 415°C.

[0055] [ka]

[0056] C-2 (Comparative Example): Aliphatic polycarbodiimide compound (manufactured by Nisshinbo Inc., Carbodilite HMV-8CA (product name), 5% weight loss temperature 320°C) (D component) D-1: Phosphonic acid ester (manufactured by Johoku Chemical Industry Co., Ltd., product name JC-224, diethylphosphonoethyl acetate, acid value 0.08 mg KOH / g) D-2 (Comparative Example): Phosphonic acid ester (Solvay, diethylphosphonoethyl acetate, acid value 0.39 mg KOH / g)

[0057] [Table 1]

[0058] <Examples 1-9> Because the resin composition falls within the scope of this claim, it exhibits excellent conductivity, carbon black shedding prevention, and abrasion resistance, and the solidified extruded product maintains a high molecular weight. <Comparative Example 1> Because the content of component B exceeded the upper limit, the carbon black did not disperse properly when the polybutylene naphthalate resin and conductive carbon black were melt-kneaded together, resulting in frequent strand drawdown and making it impossible to obtain pellets. <Comparative Example 2> Because the content of component B was below the lower limit, the conductivity deteriorated. <Comparative Example 3> Because the DBP oil absorption amount of component B exceeded the upper limit, the carbon black did not disperse during the melt-kneading of the polybutylene naphthalate resin and conductive carbon black, resulting in frequent strand drawdown and making it impossible to obtain pellets. <Comparative Example 4> Since the amount of DBP oil absorbed by component B was below the lower limit, the conductivity deteriorated. <Comparative Example 5> Because the C content exceeded the upper limit, a coarse gel-like substance was generated during kneading, causing the strands to rupture and preventing the acquisition of pellets. <Comparative Example 6> Because the C component content was below the lower limit, wear resistance and carbon black shedding prevention deteriorated, and the molecular weight after solidification extrusion molding decreased. <Comparative Example 7> Because component C is not an aromatic carbodiimide compound, wear resistance and carbon black shedding prevention deteriorated, and the molecular weight decreased after solidification and extrusion molding. <Comparative Example 8> Because the content of component D exceeded the upper limit, the wear resistance deteriorated. <Comparative Example 9> Because the content of component D was below the lower limit, wear resistance deteriorated, and the molecular weight after solidification extrusion molding decreased. <Comparative Example 10> Because the acid value of component D exceeded the upper limit, the molecular weight decreased after solidification and extrusion molding.

Claims

1. A resin composition characterized by containing, per 100 parts by weight of (A) polybutylene naphthalate resin (component A), 3 to 15 parts by weight of (B) conductive carbon black (component B) having a DBP oil absorption of 200 to 400 ml / 100 g, (C) aromatic carbodiimide compound (component C) 0.05 to 2 parts by weight, and (D) phosphonic acid ester (component D) having an acid value of 0.01 to 0.30 mg KOH / g.

2. The resin composition according to claim 1, characterized in that component C is an aromatic carbodiimide compound having a 5% weight loss temperature of 330°C or higher.

3. The resin composition according to claim 1 or 2, characterized in that component C is a cyclic carbodiimide compound represented by the following formula (1). 【Chemistry 1】 (In formula (1), X is a tetravalent group represented by the following formula (2), Ar １ ~Ar ４ Each of these is independently an orthophenylene group or a 1,2-naphthalene-diyl group, which may be substituted with an alkyl group or phenyl group having 1 to 6 carbon atoms. 【Chemistry 2】

4. The resin composition according to claim 1 or 2, characterized in that component A is a polybutylene naphthalate resin having an intrinsic viscosity of 0.95 to 1.50 dl / g.

5. A resin composition according to claim 1 or 2, used in solidification extrusion molding.

6. A molded article obtained by molding the resin composition according to claim 1 or 2.

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