JP5740916B2 - Polysulfone composition - Google Patents

Description

  The present invention relates to a polysulfone composition comprising polysulfone and carbon black.

  Polysulfone is considered as a material for various products and parts, including electrical and electronic parts, because it has excellent heat resistance and chemical resistance and has high strength and rigidity. In addition, when carbon black is blended with polysulfone, weather resistance is imparted by the ultraviolet absorption ability of carbon black, and the black color of carbon black is blackened so that the color of polysulfone becomes inconspicuous. Because of its conductivity, it is possible to impart antistatic properties or electrical conductivity, a polysulfone composition containing polysulfone and carbon black has been studied as a preferred polysulfone material. For example, Patent Document 1 describes a polysulfone composition containing 60 to 95.9 parts by mass of polysulfone and 3 to 15 parts by mass of carbon black. Patent Document 2 describes a polysulfone composition containing polysulfone and 5 to 40% by mass of carbon black having a pH of 5 or less.

Japanese Patent Laid-Open No. 3-91556 JP 2002-14548 A

  The polysulfone composition described in Patent Document 1 has a problem that the light resistance is not always sufficient, and the color tone is easily changed by light irradiation. In addition, the polysulfone compositions described in Patent Documents 1 and 2 have a problem that the original good mechanical properties of polysulfone are easily impaired. Accordingly, an object of the present invention is to provide a polysulfone composition comprising polysulfone and carbon black, having excellent light resistance and having good mechanical properties.

  In order to achieve the object, the present invention includes polysulfone and carbon black having a pH of 4 or less measured according to JIS K6221-6.4.2, and the content of the carbon black is 100 mass of the polysulfone. The polysulfone composition which is 0.01-2.5 mass parts with respect to a part is provided.

  The polysulfone composition of the present invention has excellent light resistance and good mechanical properties.

Polysulfone typically has a divalent aromatic group (residue obtained by removing two hydrogen atoms bonded to the aromatic ring from an aromatic compound), a sulfonyl group (—SO ₂ —), an oxygen atom, Is a resin having a repeating unit containing From the viewpoint of heat resistance and chemical resistance, the polysulfone preferably has a repeating unit represented by the following formula (1) (hereinafter sometimes referred to as “repeat unit (1)”). 2) (hereinafter sometimes referred to as “repeating unit (2)”) and a repeating unit represented by the following formula (3) (hereinafter referred to as “repeating unit (3)”). And other repeating units may be included.

(1) -Ph ¹ -SO ₂ -Ph ² -O-

(Ph ¹ and Ph ² each independently represent a phenylene group. The hydrogen atoms in the phenylene group may each independently be substituted with an alkyl group, an aryl group, or a halogen atom.)

(2) -Ph ³ -R-Ph ⁴ -O-

(Ph ³ and Ph ⁴ each independently represent a phenylene group. The hydrogen atoms in the phenylene group may each independently be substituted with an alkyl group, an aryl group or a halogen atom. R represents an alkylidene. Represents a group, oxygen atom or sulfur atom.)

(3)-(Ph ⁵ ) _n -O-

(Ph ⁵ represents a phenylene group. Each hydrogen atom in the phenylene group may be independently substituted with an alkyl group, an aryl group or a halogen atom. N represents an integer of 1 to 3. When n is 2 or more, a plurality of Ph ⁵ may be the same or different from each other.)

The phenylene group represented by any of Ph ^{1 to} Ph ⁵ may be a p-phenylene group, an m-phenylene group, or an o-phenylene group. -A phenylene group is preferred. Examples of the alkyl group which may be substituted for the hydrogen atom in the phenylene group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, s-butyl group, t- A butyl group, n-hexyl group, 2-ethylhexyl group, n-octyl group, and n-decyl group are mentioned, The carbon number is 1-10 normally. Examples of the aryl group which may substitute a hydrogen atom in the phenylene group include a phenyl group, o-tolyl group, m-tolyl group, p-tolyl group, 1-naphthyl group and 2-naphthyl group. The carbon number is usually 6-20. When the hydrogen atom in the phenylene group is substituted with these groups, the number is usually 2 or less and preferably 1 or less for each phenylene group.

  As an example of the alkylidene group which is R, a methylene group, an ethylidene group, an isopropylidene group, and 1-butylidene group are mentioned, The carbon number is 1-5 normally.

  The polysulfone preferably has the repeating unit (1) of 50 mol% or more, more preferably 80 mol% or more, based on the total of all repeating units, and substantially only the repeating unit (1) as the repeating unit. It is further preferable to have In addition, polysulfone may have 2 or more types of repeating units (1)-(3) each independently.

  Polysulfone can be produced by polycondensation of a dihalogenosulfone compound and a dihydroxy compound corresponding to the repeating unit constituting the polysulfone. For example, a resin having a repeating unit (1) uses a compound represented by the following formula (4) as a dihalogenosulfone compound (hereinafter sometimes referred to as “compound (4)”), and a dihydroxy compound represented by the following formula ( It can be produced by using the compound represented by 5) (hereinafter sometimes referred to as “compound (5)”). The resin having the repeating unit (1) and the repeating unit (2) uses the compound (4) as the dihalogenosulfone compound and the compound represented by the following formula (6) as the dihydroxy compound (hereinafter referred to as “compound ( 6) ", sometimes referred to as") ". In addition, the resin having the repeating unit (1) and the repeating unit (3) uses the compound (4) as the dihalogenosulfone compound and the compound represented by the following formula (7) as the dihydroxy compound (hereinafter referred to as “compound ( 7) ", which is sometimes referred to as") ".

^{(4) X 1 -Ph 1 -SO} 2 -Ph 2 -X 2

(X ¹ and X ² each independently represent a halogen atom. Ph ¹ and Ph ² are as defined above.)

(5) HO—Ph ¹ —SO ₂ —Ph ² —OH

(Ph ¹ and Ph ² are as defined above.)

^{(6) HO-Ph 3 -R} -Ph 4 -OH

(Ph ³ , Ph ⁴ and R are as defined above.)

(7) HO— (Ph ⁵ ) _n —OH

(Ph ⁵ and n are as defined above.)

  The polycondensation is preferably performed in a solvent using an alkali metal carbonate. The alkali metal salt of carbonic acid may be an alkali carbonate that is a normal salt, an alkali bicarbonate (an alkali hydrogen carbonate) that is an acidic salt, or a mixture of both. Are preferably sodium carbonate and potassium carbonate, and sodium bicarbonate and potassium bicarbonate are preferably used as the alkali bicarbonate. Examples of the solvent include dimethyl sulfoxide, 1-methyl-2-pyrrolidone, sulfolane (1,1-dioxothyrane), 1,3-dimethyl-2-imidazolidinone, 1,3-diethyl-2-imidazolidinone, dimethyl sulfone. Organic polar solvents such as diethylsulfone, diisopropylsulfone, and diphenylsulfone are preferably used.

  Polysulfone has a reduced viscosity of usually 0.3 dL / g or more, preferably 0.4 to 0.6 dL / g, more preferably 0.45 to 0.55 dL / g. The higher the reduced viscosity, the easier it is to improve the heat resistance, strength, and rigidity. However, if the reduced viscosity is too high, the melting temperature and the melt viscosity tend to increase, and the temperature required for the molding tends to increase.

  In the polycondensation, if no side reaction occurs, the closer the molar ratio of the dihalogenosulfone compound and the dihydroxy compound is to 1: 1, the greater the amount of alkali metal carbonate used, the higher the polycondensation temperature. In addition, the longer the polycondensation time, the higher the degree of polymerization of the resulting polysulfone, and the more likely the reduced viscosity is. A side reaction such as depolymerization occurs, and this side reaction tends to lower the degree of polymerization of the resulting polysulfone and reduce the reduced viscosity. Therefore, considering the degree of this side reaction, a polysulfone having a desired reduced viscosity can be obtained. The molar ratio of the dihalogenosulfone compound to the dihydroxy compound, the amount of alkali metal carbonate used, the polycondensation temperature and the polycondensation time were adjusted so that It is preferable to.

  The polysulfone composition of the present invention contains the polysulfone as described above and carbon black having a pH of 4 or less measured according to JIS K6221-6.4.2, the content of which is 100 parts by mass of polysulfone. And 0.01 to 2 parts by mass. Thus, a polysulfone composition having excellent light resistance and good mechanical properties can be obtained by blending a predetermined amount of carbon black with polysulfone.

  The carbon black having a pH of 4 or less is usually oxidized on the surface, and has an oxygen-containing group such as a carboxyl group, a quinone group, a lactone group, or a hydroxyl group on the surface. By capturing radicals generated by light, it is considered that the degradation chain reaction of polysulfone is prevented and the light resistance of the polysulfone composition is improved. The pH of carbon black is usually 2 or more.

  The content of carbon black is preferably 0.05 to 2.5 parts by mass, more preferably 0.5 to 2.5 parts by mass with respect to 100 parts by mass of polysulfone. If the carbon black content is too low, the light resistance of the polysulfone composition will be insufficient, and if it is too high, the mechanical properties of the polysulfone composition will be insufficient.

  Carbon black preferably has a number average particle size of 30 nm or less. If the number average particle diameter of the carbon black is too large, the surface area per mass becomes small, and the amount of oxygen-containing groups on the surface per mass decreases, so the light resistance of the polysulfone composition tends to be insufficient. The number average particle diameter of carbon black is more preferably 25 nm or less, and usually 10 nm or more. The number average particle diameter of carbon black can be measured by observing carbon black with an electron microscope.

  The carbon black preferably has a volatile content of 1% by mass or more with respect to the carbon black before heating when heated at 950 ° C. for 7 hours. This volatile content is considered as an index of the amount of oxygen-containing groups on the surface per mass, and if it is too small, the light resistance of the polysulfone composition tends to be insufficient. In addition, the said volatile matter of carbon black is 10 mass% or less normally.

  The polysulfone composition of the present invention may contain one or more other components such as a filler, an additive other than carbon black, and a resin other than polysulfone.

  The filler may be a fibrous filler, a plate-like filler, or a spherical or other granular filler other than the fibrous and plate-like materials. The filler may be an inorganic filler or an organic filler. Examples of fibrous inorganic fillers include glass fibers; carbon fibers such as pan-based carbon fibers and pitch-based carbon fibers; ceramic fibers such as silica fibers, alumina fibers and silica-alumina fibers; and metal fibers such as stainless steel fibers. It is done. In addition, whiskers such as potassium titanate whisker, barium titanate whisker, wollastonite whisker, aluminum borate whisker, silicon nitride whisker, and silicon carbide whisker are also included. Examples of fibrous organic fillers include polyester fibers and aramid fibers. Examples of the plate-like inorganic filler include talc, mica, graphite, wollastonite, glass flake, barium sulfate, and calcium carbonate. Mica may be muscovite, phlogopite, fluorine phlogopite, or tetrasilicon mica. Examples of the particulate inorganic filler include silica, alumina, titanium oxide, glass beads, glass balloons, boron nitride, silicon carbide and calcium carbonate. Content of the filler in a polysulfone composition is 0-100 mass parts normally with respect to 100 mass parts of polysulfone.

  Examples of additives other than carbon black include antioxidants, heat stabilizers, ultraviolet absorbers, antistatic agents, surfactants, flame retardants, and colorants other than carbon black. Content of additives other than carbon black in a polysulfone composition is 0-5 mass parts normally with respect to 100 mass parts of polysulfone.

  Examples of resins other than polysulfone include thermoplastic resins other than polysulfone such as polypropylene, polyamide, polyester, polyphenylene sulfide, polyether ketone, polycarbonate, polyphenylene ether, and polyetherimide; and phenol resin, epoxy resin, polyimide resin, and cyanate. Examples thereof include thermosetting resins such as resins. Content of resin other than polysulfone in a polysulfone composition is 0-20 mass parts normally with respect to 100 mass parts of polysulfone.

  The polysulfone composition is preferably prepared by melt-kneading polysulfone, carbon black, and other components used as necessary using an extruder and extruding them into pellets. As the extruder, one having a cylinder, one or more screws arranged in the cylinder, and one or more supply ports provided in the cylinder is preferably used, and further one place provided in the cylinder What has the above vent part is used more preferably.

  By molding the polysulfone composition of the present invention thus obtained, a molded article having excellent light resistance and good mechanical properties can be obtained. As a molding method of the polysulfone composition, a melt molding method is preferable, and examples thereof include an injection molding method, an extrusion molding method such as a T-die method and an inflation method, a compression molding method, a blow molding method, a vacuum molding method, and a press molding method. Is mentioned. Of these, the injection molding method is preferable.

  Examples of products and parts that are molded products thus obtained include bobbins such as optical pickup bobbins and transformer bobbins; relay parts such as relay cases, relay bases, relay sprues, and relay armatures; RIMM, DDR, CPU sockets, S / O, DIMM, Board to Board connector, FPC connector, card connector, etc .; Lamp reflector, LED reflector, etc .; Lamp holder, heater holder, etc .; Diaphragm, such as speaker diaphragm; Separation claws such as separation claws for printers; camera module parts; switch parts; motor parts; sensor parts; hard disk drive parts; tableware such as ovenware; Sealing members such as a sealing member for use.

  Examples of the present invention will be described below, but the present invention is not limited thereto.

Examples 1-3, Comparative Examples 1-4

[Polysulfone]
As a polysulfone, “Sumika Excel PES4800G” (reduced viscosity 0.48) manufactured by Sumitomo Chemical Co., Ltd. was used. The reduced viscosity of polysulfone is a value measured by the following method.

(Measurement of reduced viscosity of polysulfone)
About 1 g of polysulfone was dissolved in N, N-dimethylformamide to make its volume 1 dL, and the viscosity (η) of this solution was measured at 25 ° C. using an Ostwald type viscosity tube. Further, the viscosity (η ₀ ) of N, N-dimethylformamide as a solvent was measured at 25 ° C. using an Ostwald type viscosity tube. From the viscosity (η) of the solution and the viscosity (η ₀ ) of the solvent, the specific viscosity ((η−η ₀ ) / η ₀ ) is obtained, and this specific viscosity is calculated as the concentration of the solution (about 1 g / dL). ) To determine the reduced viscosity (dL / g) of polysulfone.

〔Carbon black〕
The following were used as carbon black.
Carbon black (1): “MA-100” (pH 3.5, number average particle size 24 nm, volatile matter 1.5 mass%) manufactured by Mitsubishi Chemical Corporation.
Carbon black (2): “CB # 20” (pH 7.0, number average particle size 50 nm, volatile matter 0.6 mass%) manufactured by Mitsubishi Chemical Corporation.
Carbon black (3): “CB # 32” (pH 8.0, number average particle size 30 nm, volatile content 6.0 mass%) of Mitsubishi Chemical Corporation

  Here, the pH of the carbon black is determined by boiling a mixed solution of 10 g of carbon black and 100 ml of distilled water for 15 minutes in accordance with JIS K6221-6.4.2, and then centrifuging to remove the supernatant. It is the value measured with the pH glass electrode pH meter of the mud. The number average particle size of carbon black is a value measured by observing with an electron microscope. Moreover, the volatile matter of carbon black is obtained by heating carbon black at 950 ° C. for 7 minutes and dividing its mass reduction value ([mass before heating] − [mass after heating]) by [mass before heating]. This is the calculated value.

(Preparation of polysulfone composition)
The types and amounts of carbon black shown in Table 1 were blended with 100 parts by mass of polysulfone, and dry blended with a Henschel mixer. This mixture was granulated at a cylinder temperature of 340 ° C. using a twin screw extruder (“PCM-30 type” manufactured by Ikekai Tekko Co., Ltd.) to obtain a pelleted polysulfone composition.

[Evaluation of light resistance]
The polysulfone composition was molded into a 64 mm × 64 mm × 3 mm test piece at a cylinder temperature of 370 ° C. and a mold temperature of 150 ° C. using an injection molding machine (“PS-20E5ASE” manufactured by Nissei Plastic Industry Co., Ltd.). . Using a weatherometer ("WBL 75XS": xenon type from Suga Test Instruments Co., Ltd.) for this test piece, surface irradiation illuminance of 160 W / m ² , measurement wavelength of 300 to 400 nm, black panel temperature of 60 ° C, relative humidity Light irradiation was performed for 24 hours under the condition of 50%. For the test pieces before and after the light irradiation, using a color difference meter (“CM-3600d” manufactured by Minolta Co., Ltd.), the light receiving optical system D65, the C light source, the observation visual field 10 °, and the measurement diameter 25.4 mm, Without cutting, the chromaticity (L *, a *, b *) by the L * a * b * color system was measured, and the color difference ΔE * ab by the SCE method was calculated. The results are shown in Table 1.

[Evaluation of impact resistance]
A test of 127 mm × 12.7 mm × 6.4 mm with a polysulfone composition using an injection molding machine (“PS-20E5ASE” manufactured by Nissei Plastic Industry Co., Ltd.) at a cylinder temperature of 370 ° C. and a mold temperature of 150 ° C. Molded into pieces. This test piece was divided into two equal parts, and Izod impact strength was measured according to ASTM D-256. The results are shown in Table 1.

Claims (5)

Polysulfone and carbon black having a pH measured according to JIS K6221-6.4.2 of 4 or less, and the content of the carbon black is 0.01 to 2 with respect to 100 parts by mass of the polysulfone . A polysulfone composition which is 0 parts by mass. The polysulfone composition according to claim 1, wherein the polysulfone is a polysulfone having a repeating unit represented by the following formula (1).
(1) -Ph ¹ -SO ₂ -Ph ² -O-
(Ph ¹ and Ph ^2- each independently represents a phenylene group. The hydrogen atoms in the phenylene group may each independently be substituted with an alkyl group, an aryl group or a halogen atom.)   The polysulfone composition according to claim 2, wherein the polysulfone is a polysulfone having 50 mol% or more of the repeating unit represented by the formula (1) with respect to the total amount of all repeating units constituting the polysulfone.   The polysulfone composition according to any one of claims 1 to 3, wherein the carbon black has a number average particle diameter of 30 nm or less.   The polysulfone composition according to any one of claims 1 to 4, wherein a volatile content when the carbon black is heated at 950 ° C for 7 hours is 1% by mass or more with respect to the carbon black.