JP2021116355A - Polyarylene sulfide resin composition - Google Patents

Abstract

To provide a resin composition that is excellent in low gas properties and high cycle moldability while maintaining excellent strength.SOLUTION: A resin composition comprises, based on (A) a polyarylene sulfide resin (A component) of 100 pts.wt., (B) a PAN-based carbon fiber (B component) with a sizing agent being a polyimide resin of 10-150 pts.wt.SELECTED DRAWING: None

Description

The present invention is a resin composition composed of a polyarylene sulfide resin and a PAN-based carbon fiber in which the sizing agent is a polyimide resin, and is excellent in low gas property and high cycle moldability while maintaining excellent strength. It is about.

Polyarylene sulfide resin is an engineering plastic having excellent chemical resistance, heat resistance, mechanical properties, and the like. Therefore, the polyarylene sulfide resin is widely used as a metal substitute material in applications such as electrical and electronic engineering, vehicle-related, aircraft, and housing by taking advantage of its excellent properties. In particular, recently, due to the increasing demand for weight reduction, application to members requiring high mechanical strength and rigidity is being studied. As a method for improving the mechanical strength and rigidity of a polyarylene sulfide resin, a method of filling polyarylene sulfide with carbon fibers is known. However, since the polyarylene sulfide resin has a high molding temperature, there is a problem that the amount of outgas is large and the workability is lowered. Further, recently, there has been a demand for high cycle molding of a polyarylene sulfide resin for the purpose of improving productivity, and a polyarylene sulfide resin having a higher cycle moldability than the conventional one is required.

As an attempt to improve the outgassing property of the polyarylene sulfide resin, for example, a resin composition composed of carbon fibers having a tensile elasticity of 350 to 500 GPa and a sizing agent adhering amount of 1.0 to 2.0% by weight and polyarylene sulfide. (Patent Document 1), Resin composition consisting of carbon fiber and thermoplastic resin having a weight loss of 0.5% or less at 400 ° C. in an inert atmosphere (Patent Document 2), carbon heat-treated at 250 to 330 ° C. A resin composition composed of fibers and a thermoplastic resin (Patent Document 3) has been proposed. However, it cannot be said that the outgassing property is sufficient, and no description is made about the high cycle moldability.

JP-A-2017-190426 Japanese Unexamined Patent Publication No. 5-229869 Japanese Unexamined Patent Publication No. 10-1877

An object of the present invention is to provide a resin composition having excellent low gas properties and high cycle moldability while maintaining excellent strength.

As a result of diligent studies by the present inventor, a resin composition composed of a polyarylene sulfide resin and a PAN-based carbon fiber whose sizing agent is a polyimide resin has low gas properties and high cycle moldability while maintaining excellent strength. The present invention has been made by finding that it is an excellent resin composition.

Specifically, the above-mentioned problem is to (A) 100 parts by weight of the polyarylene sulfide resin (component A) and (B) 10 to 150 parts by weight of PAN-based carbon fiber (component B) in which the sizing agent is a polyimide resin. Achieved by the resin composition contained.

Hereinafter, the details of the present invention will be described.

(Component A: Polyarylene sulfide resin)
As the polyarylene sulfide resin used as the component A of the present invention, any polyarylene sulfide resin may be used as long as it belongs to the category called polyarylene sulfide resin.

The polyarylene sulfide resin has, as its constituent units, for example, p-phenylene sulfide unit, m-phenylene sulfide unit, o-phenylene sulfide unit, phenylene sulfide sulfide unit, phenylene sulfide ketone unit, phenylene sulfide ether unit, diphenylene sulfide unit. , Substituent-containing phenylene sulfide unit, branched structure-containing phenylene sulfide unit, etc. Among them, those containing p-phenylene sulfide unit in an amount of 70 mol% or more, particularly 90 mol% or more. Preferably, poly (p-phenylene sulfide) is more preferable.

The dispersity (Mw / Mn) represented by the weight average molecular weight (Mw) and the number average molecular weight (Mn) of the polyarylene sulfide resin used as the component A of the present invention is preferably 2.7 or more, more preferably 2 It is 8.8 or more, more preferably 2.9 or more. If the degree of dispersion is less than 2.7, burrs may be generated during molding. The upper limit of the degree of dispersion (Mw / Mn) is not particularly specified, but is preferably 10 or less. Here, the weight average molecular weight (Mw) and the number average molecular weight (Mn) are values calculated in terms of polystyrene by gel permeation chromatography (GPC). 1-Chloronaphthalene was used as a solvent, and the column temperature was 210 ° C.

The method for producing the polyarylene sulfide resin is not particularly limited, and the polyarylene sulfide resin is polymerized by a known method. For example, the production methods described in US Registered Patents No. 4,746,758, No. 4,786,713, Japanese Patent Application Laid-Open No. 2013-522385, Japanese Patent Application Laid-Open No. 2012-233210, Patent No. 5167276, and the like can be mentioned. These production methods are methods in which a diiodoaryl compound and solid sulfur are directly heated and polymerized without a polar solvent.

The production method includes an iodide step and a polymerization step. In the iodination step, the aryl compound is reacted with iodine to obtain a diiodoaryl compound. In the subsequent polymerization step, a polyarylene sulfide resin is produced by polymerizing a diiodoaryl compound with solid sulfur using a polymerization terminator. Iodine is generated in the form of gas in this step, and it is recovered and used again in the iodination step. Iodine is essentially a catalyst.

As a typical solid sulfur used in the above-mentioned production method, a cyclooctasulfur form (S8 _{) in which eight} atoms are linked at room temperature can be mentioned. However, the sulfur compound used in the polymerization reaction is not limited, and any form can be used as long as it is solid or liquid at room temperature.

Typical diiodoaryl compounds used in the above-mentioned production method include at least one selected from the group consisting of diiodobenzene, diiodonaphthalene, diiodobiphenyl, diiodobisphenol and diiodobenzophenone, and alkyl. Derivatives of iodoaryl compounds to which groups or sulfon groups are bonded or oxygen or nitrogen is introduced are also used. Iodoaryl compounds are classified into different isomers depending on the bond position of the iodine atom, and preferred examples of these isomers are p-diiodobenzene, 2,6-diiodonaphthalene, and p, p'-diiode. A compound such as biphenyl in which iodo is symmetrically located at both ends of the aryl compound molecule. The content of the iodoaryl compound is preferably 500 to 10,000 parts by weight with respect to 100 parts by weight of the solid sulfur. This amount is determined in consideration of the formation of disulfide bonds.

Typical polymerization inhibitors used in the above production method include monoiodoaryl compounds, benzothiazoles, benzothiazolesulfenamides, thiurams, dithiocarbamates, aromatic sulfide compounds and the like. Preferred examples of the monoiodoaryl compound include at least one selected from the group consisting of iodobiphenyl, iodophenol, iodoaniline, and iodobenzophenone. Preferred examples of the benzothiazoles include at least one selected from the group consisting of 2-mercaptobenzothiazole and 2,2'-dithiobisbenzothiazole. Preferred examples of the benzothiazole sulfenamides are N-cyclohexylbenzothiazole2-sulfenamide, N, N-dicyclohexyl-2-benzothiazolesulfenamide, 2-morpholinothiobenzothiazole, benzothiazolesulfenamide. , Dibenzothiazole disulfide, N-dicyclohexylbenzothiazole 2-sulfenamide, at least one selected from the group. Preferred examples of thiurams include at least one selected from the group consisting of tetramethylthiuram monosulfide and tetramethylthiuram disulfide. Preferred examples of the dithiocarbamates include at least one selected from the group consisting of zinc dimethyldithiocarbamate and zinc diethyldithiocarbamate. Preferred examples of the aromatic sulfide compound include at least one selected from the group consisting of diphenyl sulfide, diphenyl disulfide, diphenyl ether, biphenyl and benzophenone. Further, in any of the polymerization inhibitors, one or more functional groups may be substituted on the conjugated aromatic ring skeleton. Examples of the functional group include a hydroxy group, a carboxy group, a mercapto group, an amino group, a cyano group, a sulfo group, a nitro group and the like, and preferred examples include a carboxy group and an amino group, with more preferred examples thereof. in the FT-IR spectrum, a carboxy group indicating the peak of 1600～1800Cm ^-1 or 3300～3500Cm ^-1, and amino groups. The content of the polymerization inhibitor is preferably 1 to 30 parts by weight with respect to 100 parts by weight of the solid sulfur. This amount is determined in consideration of the formation of disulfide bonds.

A polymerization reaction catalyst may be used in the above-mentioned production method, and a nitrobenzene-based catalyst can be mentioned as a typical polymerization reaction catalyst. Preferred examples of nitrobenzene-based catalysts are 1,3-diiodo-4-nitrobenzene, 1-iodo-4-nitrobenzene, 2,6-diiodo-4-nitrophenol, iodonitrobenzene, and 2,6-diiodo-4-. At least one selected from the group consisting of nitroamines can be mentioned. The content of the polymerization reaction catalyst is preferably 0.01 to 20 parts by weight with respect to 100 parts by weight of the solid sulfur. This amount is determined in consideration of the formation of disulfide bonds.

By using this polymerization method, it is not necessary to substantially reduce the chlorine content and the sodium content, and a polyphenylene sulfide resin having excellent cost performance can be obtained.

Further, the polyphenylene sulfide resin of the present invention may contain a polyphenylene sulfide resin obtained by another polymerization method.

(B component: PAN-based carbon fiber)
The carbon fiber used in the present invention is a PAN-based carbon fiber whose sizing agent is a polyimide resin. When the sizing agent is not a polyimide resin, it is inferior in low gas property, crystallization rate and high cycle moldability.

The fiber diameter of the carbon fiber is not particularly limited, but is preferably 3 to 15 μm, and more preferably 4 to 13 μm. A carbon fiber having an average fiber diameter in such a range may be able to exhibit good mechanical properties without impairing the appearance of the molded product.

The amount of the sizing agent for the component B is preferably 0.5 to 4.0% by weight, more preferably 1.0 to 3.0% by weight. If the amount of the sizing agent adhered to the component B is less than 0.5% by weight, the productivity or molding processability may decrease, and if it exceeds 4.0% by weight, the amount of outgas may increase.

The sizing treatment may be any method, for example, a method in which a sizing agent is passed through a sizing solution in the state of a strand to apply a sizing agent, or a method in which a strand is cut and then kneaded with a sizing agent in a mixer for sizing. Examples thereof include a method in which the agent is applied.

The content of the B component is 10 to 150 parts by weight, preferably 15 to 130 parts by weight, and more preferably 20 to 100 parts by weight with respect to 100 parts by weight of the A component. If the content of the B component is less than 10 parts by weight, sufficient mechanical strength and crystallization rate cannot be obtained, and the high cycle moldability is inferior. On the other hand, if it exceeds 150 parts by weight, the productivity or moldability is lowered.

(Other ingredients)
In the resin composition of the present invention, an inorganic filler other than carbon fiber can be used in combination as long as the effect of the present invention is not impaired. Examples of the inorganic filler include fibrous fillers other than carbon fibers, powder-like fillers, and plate-like fillers. As fibrous fillers, glass fibers, aramid fibers, potassium titanate whisker, zinc oxide whisker, alumina fibers, silicon carbide fibers, ceramic fibers, asbestos fibers, stone shaving fibers, metal fibers, and inorganic fibers coated with a conductive substance. And so on. Specific examples of the conductive substance in the inorganic fiber coated with the conductive substance include aluminum, nickel, silver, carbon, SnO ₂ (antimony doping), and In ₂ O ₃ (antimony doping). Examples of the inorganic fiber to be coated include glass fiber, potassium titanate whiskers, zinc oxide whiskers, titanic acid whiskers, silicon carbide whiskers and the like. Examples of the coating method include a vacuum vapor deposition method, a sputtering method, an electroless plating method, and a baking method. Further, these may be surface-treated with a surface treatment agent such as a titanate-based, aluminum-based, or silane-based coupling agent. Further, it is more excellent mechanical strength to use these fibrous fillers by pretreating them with a coupling agent such as an isocyanate compound, an organic silane compound, an organic titanate compound, an organic borane compound and an epoxy compound. It is preferable in the sense of obtaining. Examples of the powder-like filler include carbon black, calcium carbonate, silica, titanium oxide, graphite, carbon nanotubes and the like, and examples of the plate-like filler include talc and mica.

The resin composition in the present invention may contain an elastomer component as long as the effects of the present invention are not impaired. Suitable elastomer components include core-shells such as acrylonitrile-butadiene-styrene copolymer (ABS resin), methyl methacrylate, butadiene-styrene copolymer (MBS resin) and silicone-acrylic composite rubber-based graft copolymer. Examples thereof include graft copolymer resins, and thermoplastic elastomers such as silicone-based thermoplastic elastomers, olefin-based thermoplastic elastomers, polyamide-based thermoplastic elastomers, polyester-based thermoplastic elastomers, and polyurethane-based thermoplastic elastomers.

The resin composition in the present invention may contain other thermoplastic resins as long as the effects of the present invention are not impaired. Examples of other thermoplastic resins include general-purpose plastics typified by polyethylene resin, polypropylene resin, polyalkyl methacrylate resin, polyphenylene ether resin, polyacetal resin, aromatic polyester resin, liquid crystal polyester resin, polyamide resin, and cyclic resin. Engineering plastics typified by polyolefin resins, polyarylate resins (acrystalline polyarylate, liquid crystal polyarylate), etc., polytetrafluoroethylene, polyether ether ketone, polyetherimide, polysulfone, polyether sulfone, etc. The so-called super engineering plastics can be mentioned.

The resin composition in the present invention is an antioxidant, a heat-resistant stabilizer (hindered phenol-based, hydroquinone-based, phosphite-based, and substitutes thereof, etc.) and a weather-resistant agent (resorcinol-based, etc.) as long as the effects of the present invention are not impaired. Salicylate type, benzotriazole type, benzophenone type, hindered amine type, etc.), antistatic agent and lubricant (montanoic acid and its metal salt, its ester, its half ester, stearyl alcohol, stearamide, various bisamides, bisurea and polyethylene wax, etc.) , Pigments (cadmium sulfide, phthalocyanine, carbon black, etc.), dyes (niglosin, etc.), crystal nucleating agents (talc, silica, kaolin, clay, etc.), plastic agents (octyl p-oxybenzoate, N-butylbenzenesulfonamide, etc.) ), Antistatic agents (alkylsulfate-type anionic antistatic agents, quaternary ammonium salt-type cationic antistatic agents, nonionic antistatic agents such as polyoxyethylene sorbitan monostearate, betaine-based amphoteric antistatic agents, etc. ), Flame retardant (red phosphorus, phosphate ester, melamine cyanurate, magnesium hydroxide, hydroxides such as aluminum hydroxide, ammonium polyphosphate, brominated polystyrene, brominated polyphenylene ether, brominated polycarbonate, brominated epoxy resin Alternatively, a combination of these bromine-based flame retardants and antimony trioxide, etc.) and other polymers can be added.

(Manufacturing of resin composition)
The resin composition of the present invention can be produced by mixing the above components simultaneously or in any order with a mixer such as a tumbler, a V-type blender, a Nauter mixer, a Banbury mixer, a kneading roll, or an extruder. Melt-kneading with a twin-screw extruder is preferable, and if necessary, any component is preferably supplied from the second supply port into the other components melt-mixed by using a side feeder or the like.

The resin extruded as described above is directly cut and pelletized, or the strands are cut with a pelletizer after forming the strands and pelletized. When it is necessary to reduce the influence of external dust and the like during pelletization, it is preferable to clean the atmosphere around the extruder. The shape of the obtained pellet can take a general shape such as a cylinder, a prism, and a sphere, but more preferably a cylinder. The diameter of such a cylinder is preferably 1 to 5 mm, more preferably 1.5 to 4 mm, still more preferably 2 to 3.5 mm. On the other hand, the length of the cylinder is preferably 1 to 30 mm, more preferably 2 to 5 mm, still more preferably 2.5 to 4 mm.

(About molded products)
A molded product using the resin composition of the present invention can be obtained by molding pellets produced as described above. Preferably, it is obtained by injection molding or extrusion molding. In 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, and heat insulating metal. Examples thereof include mold molding, rapid heating and cooling mold molding, two-color molding, multicolor molding, sandwich molding, and ultra-high-speed injection molding. Further, either a cold runner method or a hot runner method can be selected for molding. Further, in extrusion molding, various deformed extrusion molded products, sheets, films and the like can be obtained. Inflation method, calendar method, casting method, etc. can also be used for forming sheets and films. Further, it can be molded as a heat-shrinkable tube by applying a specific stretching operation. Further, the resin composition of the present invention can be made into a molded product by rotary molding, blow molding or the like.

Since the resin composition of the present invention is excellent in low gas property and high cycle moldability while maintaining excellent strength, it is used for personal computers (notebooks, ultrabooks), tablets, housings for mobile phones, hybrid vehicles and electric vehicles. Inverter housing, display, OA equipment, mobile phone, mobile information terminal, facsimile, compact disk, portable MD, portable radio cassette, PDA (personal digital assistant, etc.), video camera, digital still camera, optical equipment, Audio, air conditioners, lighting equipment, entertainment products, toy products, other electrical and electronic equipment housings and internal parts such as trays and chassis, and their cases, mechanical parts, panels and other building materials, motor parts, alternators. Terminals, alternator connectors, IC regulators, radiator bases, suspension parts, exhaust gas valves and other valves, fuel-related, exhaust or intake system pipes, air intake nozzle snorkels, intake manifolds, various arms, various frames, Various hinges, various bearings, fuel pumps, gasoline tanks, CNG tanks, engine cooling water joints, carburetor main bodies, carburetor spacers, exhaust gas sensors, cooling water sensors, oil temperature sensors, brake pad wear sensors, throttle position sensors, crank shafts Position sensor, air flow meter, brake butt wear sensor, thermostat base for air conditioner, heating hot air flow control valve, brush holder for radiator motor, water pump impeller, turbine vane, wiper motor related parts, distributor, starter switch, Starter relay, wire harness for transmission, window washer nozzle, air conditioner panel switch board, fuel related electromagnetic valve coil, fuse connector, battery tray, AT bracket, head lamp support, pedal housing, handle, door beam, protector, chassis, frame , Armrest, horn terminal, step motor rotor, lamp socket, lamp reflector, lamp housing, brake piston, noise shield, radiator support, spare tire cover, seat shell, solenoid bobbin, engine oil filter, ignition Equipment cases, undercovers, scuff plates, pillar trims, propeller shafts, wheels, fenders, facers, bumpers, bumper beams, bonnets, aero parts, platforms, cowl louvers, roofs, instrument panels, spoilers and various modules for automobiles and motorcycles. It is widely useful in related parts, parts and skins, landing gear pods, winglets, spoilers, edges, rudder, elevators, failing, ribs and other aircraft related parts, parts and skins, windmill blades and the like.

The embodiment of the present invention, which the present inventor considers to be the best at present, is a collection of preferable ranges of the above-mentioned requirements. For example, a representative example thereof will be described in the following examples. Of course, the present invention is not limited to these forms.

[Evaluation of resin composition]
(1) Tensile breaking strength Measured according to ISO527 (measurement condition 23 ° C.). The test piece was molded by the following method. The larger this value is, the more excellent the mechanical strength of the resin composition is.
(2) Amount of outgas The pellets were pre-dried at 130 ° C. for 6 hours. 10 g of the dried pellets were heated in a muffle furnace (VTDS-2R manufactured by Isuzu Seisakusho Co., Ltd.) at 320 ° C. for 1 hour and left at room temperature for 12 hours. Then, the weight of the pellet was measured, and the weight loss rate (% by weight) was calculated as the outgas amount from the weight before heating and the weight after heating. The smaller this value is, the more excellent the low gas property of the resin composition is.
(3) Crystallization rate Using the thermal analysis system DSC-2910 manufactured by TA Instruments Japan Co., Ltd., the temperature was raised from room temperature at a rate of 20 ° C./min, and when the temperature reached 340 ° C., the temperature was maintained for 5 minutes. Then, it was cooled to room temperature, and the temperature was raised again at a rate of 20 ° C./min. When the temperature reached 340 ° C., the temperature was maintained for 5 minutes, the temperature was lowered at a rate of 20 ° C./min, and the crystallization peak temperature observed during the temperature lowering was measured. In general, the higher the temperature-decreasing crystallization peak temperature, the faster the crystallization proceeds.
(4) High Cycle Moldability A molded product having a size of 150 × 150 × 2 mm was molded under the following conditions, and the molding cycle time was measured without any problem in releasing the molded product.

[Examples 1 to 4, Comparative Examples 1 to 5]
Pellets were obtained by melt-kneading the polyarylene sulfide resin and carbon fibers at the respective blending amounts shown in Table 1 using a bent twin-screw extruder. The vent type twin-screw extruder used was TEX30α-38 (completely engaged, rotating in the same direction) manufactured by The Japan Steel Works, Ltd. The extrusion conditions were a discharge rate of 20 kg / h, a screw rotation speed of 200 rpm, a degree of vacuum of the vent of 3 kPa, and an extrusion temperature of 320 ° C. from the first supply port to the die portion. The carbon fibers were supplied from the second supply port using the side feeder of the extruder, and the polyarylene sulfide resin was supplied to the extruder from the first supply port. The first supply port referred to here is the supply port farthest from the die, and the second supply port is a supply port located between the die of the extruder and the first supply port. The obtained pellets are dried at 130 ° C. for 6 hours in a hot air circulation type dryer, and then evaluated by an injection molding machine (EC160NII-4Y manufactured by Toshiba Machine Co., Ltd.) at a cylinder temperature of 320 ° C. and a mold temperature of 140 ° C. The test piece of was molded.

Each component of the symbol notation in Table 1 is as follows.
<Component A>
A-1: Polyphenylene sulfide resin obtained by the following production method [Production method]
To 300.00 g of paradiiodobenzene and 27.00 g of sulfur, 0.60 g of diphenyl disulfide (content of 0.65% by weight based on the weight of finally polymerized PPS) was added as a polymerization inhibitor to 180 ° C. After heating to completely melt and mix them, the temperature was raised to 220 ° C. and the pressure was lowered to 200 Torr. The obtained mixture was polymerized for 8 hours while gradually changing the temperature and pressure so that the final temperature and pressure were 320 ° C. and 1 Torr, respectively, to produce a polyphenylene sulfide resin.
<B component>
B-1: HT P722 (manufactured by Teijin Limited, fiber diameter: 7 μm, cut length: 3 mm, polyimide resin-based sizing agent, sizing agent adhesion amount: 1.0% by weight)
B-2: PCS171100 (manufactured by Teijin Limited, fiber diameter: 5 μm, cut length: 3 mm, polyimide resin-based sizing agent, sizing agent adhesion amount: 2.7% by weight)
B-3: HT C432 (manufactured by Teijin Limited, fiber diameter: 7 μm, cut length: 6 mm, urethane-based sizing agent, sizing agent adhesion amount: 2.3% by weight)
B-4: HT C702 (manufactured by Teijin Limited, fiber diameter: 7 μm, cut length: 6 mm, urethane-based sizing agent, sizing agent adhesion amount: 1.8% by weight)

Claims (5)

A resin composition containing 10 to 150 parts by weight of PAN-based carbon fiber (component B) in which the sizing agent is a polyimide resin with respect to 100 parts by weight of the polyarylene sulfide resin (component A). The resin composition according to claim 1, wherein the amount of the sizing agent adhered to the component B is 0.5 to 4.0% by weight based on the component B. The component A is a polyarylene sulfide resin obtained by directly heating and polymerizing a diiodoaryl compound, solid sulfur, and a polymerization terminator and / or a polymerization reaction catalyst without using a polar solvent. The resin composition according to claim 1 or 2. (A) A method for producing a resin composition containing 10 to 150 parts by weight of PAN-based carbon fiber (B component) in which the sizing agent is a polyimide resin with respect to 100 parts by weight of the polyarylene sulfide resin (A component). The component A is a polyarylene sulfide resin obtained by directly heating and polymerizing a diiodoaryl compound, solid sulfur, and a polymerization terminator and / or a polymerization reaction catalyst without using a polar solvent. The method for producing a resin composition according to claim 4.