Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/36—Layered products comprising a layer of synthetic resin comprising polyesters
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B5/00—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts
  • B32B5/22—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed
  • B32B5/24—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed one layer being a fibrous or filamentary layer
  • B32B5/28—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed one layer being a fibrous or filamentary layer impregnated with or embedded in a plastic substance
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
  • C08J5/04—Reinforcing macromolecular compounds with loose or coherent fibrous material

Definitions

• the present invention relates to a fiber reinforced plastic molding material and a fiber reinforced plastic molded body.
• Aromatic polyester resin typified by polyethylene terephthalate (PET) is a thermoplastic resin with excellent injection moldability and mechanical properties, and has been used for various purposes since ancient times.
• PET polyethylene terephthalate
• Patent Document 1 states that the aromatic polyester resin and the phenoxy resin are crosslinked (gelled) by adding a small amount of a compound selected from a carbonate compound and a monoepoxy compound to the resin composition of the aromatic polyester resin and the phenoxy resin.
• Patent Document 2 is an invention utilizing a reaction between an aromatic polyester resin and a blended epoxy compound and a hydroxy group-containing resin, and a blending of a fiber reinforcing material is also disclosed.
• the target is an injection molding material using, and there is no mention of cross-linking the resin or combining with a continuous fiber sheet.
• Patent Document 3 regarding a fiber-reinforced plastic molding material, a sheet made of a reinforcing fiber material is immersed in a suspension bath in which a thermoplastic resin powder is dispersed in a solvent, and the sheet is heated to melt the resin powder and strengthen it.
• a method for producing a prepreg having excellent uniformity by integrating a fiber material and a thermoplastic resin is disclosed, but since it is a method of impregnating a dispersion liquid of resin particles with a reinforcing fiber base material and adhering it, impregnation or drying The production efficiency is low.
• An object of the present invention is a fiber-reinforced plastic molding material using a reinforcing fiber base material made of a continuous fiber sheet and using a crosslinkable thermoplastic resin composition having excellent heat resistance and mechanical strength as a matrix resin, and a fiber-reinforced plastic molding material thereof. It is to provide a molded body.
• the present invention is a fiber-reinforced plastic molding material in which a continuous fiber sheet is impregnated with a matrix resin composition, wherein the matrix resin composition contains an aromatic polyester resin and a phenoxy resin, and thermal cross-linking is performed between the two types of resins. It is a resin composition that also exhibits curability due to It is a fiber reinforced plastic molding material characterized in that the content ratio of the aromatic polyester resin and the phenoxy resin (aromatic polyester resin: phenoxy resin) is in the range of 5: 5 to 1: 9 by weight.
• the aromatic polyester resin is preferably either polyethylene terephthalate or polybutylene terephthalate, and the continuous fiber sheet is one or two selected from carbon fiber, glass fiber, aramid fiber, and basalt fiber. It is preferable that the unidirectional reinforcing fiber base material or the cloth material made of the above reinforcing fibers is used.
• the amount of change in the melt viscosity of the resin composition to be the matrix resin depending on the temperature is in the range of the melting point (Tm) ⁇ 20 ° C. of the aromatic polyester resin blended in the resin composition. It is preferably 2200 to ⁇ 50 Pa ⁇ s / ° C.
• Tm melting point
• the rate of increase in the melt viscosity after holding for 20 minutes at 270 ° C is 100% with respect to the minimum value. The above is preferable.
• the present invention is a fiber-reinforced plastic molded body formed by laminating the fiber-reinforced plastic molding material.
• the fiber-reinforced plastic molded product of the present invention can be produced by heat-press molding a plurality of laminated fiber-reinforced plastic molding materials at a temperature equal to or higher than the melting point (Tm) of an aromatic polyester resin.
• the fiber-reinforced plastic molding material of the present invention is reinforced with a continuous fiber sheet in addition to high heat resistance, mechanical properties, and molding processability by using a resin composition of aromatic polyester and phenoxy resin as a matrix resin. It is possible to provide a fiber reinforced plastic molded product having a higher mechanical strength than short fibers. Therefore, it can be suitably used for manufacturing not only electronic / electrical equipment parts and automobile parts but also composite materials in fields such as aerospace where higher performance is required.
• the fiber-reinforced plastic molding material of the present invention is a fiber-reinforced plastic molding material in which a continuous fiber sheet made of reinforcing fibers is impregnated with a resin composition as a matrix.
• the continuous fiber sheet made of reinforcing fibers is created by using continuous reinforcing fibers made of at least one kind selected from organic fibers such as carbon fibers, glass fibers, aramid fibers, and basalt fibers.
• a sheet-shaped reinforcing fiber base material more specifically, a continuous fiber sheet called a unidirectional reinforcing fiber base material (UD material) in which continuous reinforcing fibers are aligned in one direction and then cut into a sheet. It is a reinforcing fiber base material called a cloth material, which is made into a sheet as a woven fabric by plain weaving or twill weaving continuous reinforcing fibers with a weaving machine.
• the reinforced plastic molding material of the present invention is a fiber reinforced plastic molding material in which short fibers obtained by cutting continuous fibers into several mm to several tens of mm are blended in a resin composition, or a continuous fiber bundle impregnated with the resin composition in advance is cut.
• the fiber length of the reinforced fiber is long, so that the mechanical strength as a molded body is excellent.
• thermoplastic resin composition which is a matrix resin of the fiber-reinforced plastic molding material of the present invention, is a resin composition obtained by blending an aromatic polyester and a phenoxy resin, and the blending ratio of the aromatic polyester and the phenoxy resin (fragrance).
• Group polyester: phenoxy resin is a resin composition blended in a ratio of 8: 2 to 0.5: 99.5.
• the blending ratio of both is preferably 7: 3 to 1: 9, more preferably 6: 4 to 2: 8, and most preferably 6: 4 to 4: 6.
• thermoplastic resin composition which is a matrix resin of the fiber reinforced plastic molding material of the present invention, has a melt viscosity at a temperature of ⁇ 20 ° C. at the melting point of aromatic polyester mixed with the phenoxy resin (for example, polyethylene terephthalate is 250 ° C.).
• the amount of change is preferably in the range of -2200 Pa ⁇ s / ° C to ⁇ 20 Pa ⁇ s / ° C.
• the amount of change in the melt viscosity is the rate of change in the viscosity of the resin melt as the temperature fluctuates, and the larger the slope, the more the resin flows at once during melting.
• the slope of the melt viscosity is preferably ⁇ 2000 Pa ⁇ s / ° C to ⁇ 25 Pa ⁇ s ⁇ / ° C., and more preferably -1700 Pa ⁇ s / ° C. to ⁇ 30 Pa ⁇ s / ° C.
• the phenoxy resin blended with the aromatic polyester resin in the present invention is a thermoplastic resin obtained by a condensation reaction between a dihydric phenol compound and epihalohydrin or a polyaddition reaction between a divalent phenol compound and a bifunctional epoxy resin.
• a thermoplastic resin obtained by a condensation reaction between a dihydric phenol compound and epihalohydrin or a polyaddition reaction between a divalent phenol compound and a bifunctional epoxy resin.
• the average molecular weight of the phenoxy resin is usually 10,000 to 200,000, preferably 20,000 to 100,000, and more preferably 30,000 to 80,000 as the mass average molecular weight (Mw). be. If Mw is too low, the strength of the molded product is inferior, and if it is too high, workability and workability are likely to be inferior. In addition, Mw shows the value measured by gel permeation chromatography (GPC) and converted using the standard polystyrene calibration curve.
• GPC gel permeation chromatography
• the phenoxy resin preferably has a glass transition temperature (Tg) of 65 ° C. to 160 ° C., but is preferably 70 ° C. to 150 ° C. If the Tg is lower than 65 ° C., the moldability is improved, but there are problems in the handleability and the tackiness of the prepreg. On the other hand, if Tg is higher than 160 ° C., the melt viscosity is also increased accordingly, so that the moldability and the filling property between fibers are lowered, the strength of the molded product is lowered, and the molding temperature needs to be raised. ..
• the glass transition temperature of the phenoxy resin is a numerical value obtained from the peak value of the second scan, measured in the range of 20 to 280 ° C. under a temperature rise condition of 10 ° C./min using a differential scanning calorimetry device.
• the melt viscosity of the phenoxy resin is preferably 4000 Pa ⁇ s or less in any of the temperature ranges of 200 to 280 ° C. It is more preferably 3500 Pa ⁇ s or less, and most preferably 3000 Pa ⁇ s or less. If the melt viscosity exceeds 4000 Pa ⁇ s in any of the temperature ranges of 200 to 280 ° C., the fluidity of the matrix resin during the molding process deteriorates, so that the resin does not sufficiently spread in the continuous fiber sheet as the fiber base material. Voids are generated in the molded product, and the mechanical properties of the molded product are deteriorated.
• the hydroxyl group equivalent (g / eq) of the phenoxy resin is usually 50 to 1000 g / eq, preferably 50 to 750 g / eq, and more preferably 50 to 500 g / eq. If the hydroxyl group equivalent is too low, the water absorption rate increases due to the increase in hydroxyl groups, and there is a concern that the mechanical properties may deteriorate. If the hydroxyl group equivalent is too high, the number of hydroxyl groups is small, which hinders the improvement of heat resistance by reducing the wettability with the continuous fiber sheet constituting the reinforcing fiber base material and reducing the cross-linking points.
• the hydroxyl group equivalent of the phenoxy resin referred to in the present specification means a secondary hydroxyl group equivalent.
• the phenoxy resin is not particularly limited as long as it satisfies the above desired physical properties, but is bisphenol A type phenoxy resin (for example, phenotote YP-50, YP-50S, YP-55U manufactured by Nittetsu Chemical & Materials), bisphenol F type phenoxy.
• Resin for example, Phenotote FX-316 manufactured by Nittetsu Chemical & Material
• bisphenol A and bisphenol F copolymerized phenoxy resin for example, YP-70 manufactured by Nittetsu Chemical & Material
• special phenoxy resin other than the above for example
• the matrix resin composition is made by blending a phenoxy resin with an aromatic polyester resin.
• the main chain of an aromatic polyester resin is decomposed by thermal oxidative deterioration, resulting in a decrease in molecular weight and an increase in the amount of carboxy-terminal groups.
• the mechanical properties of the molded product decrease.
• the ester bond of the main chain is cleaved by hydrolysis to generate a carboxy terminal group and a hydroxy terminal group.
• the carboxy-terminal group generated by this hydrolysis becomes a factor that further promotes the cleavage of the ester bond, and as a result of accelerating the cleavage of the main chain, the molecular weight is further lowered and the mechanical properties of the molded product are lowered.
• the matrix resin composition is a resin composition obtained by blending a phenoxy resin and an aromatic polyester, and also has crosslinkability by heating during a molding process or the like. This cross-linking reaction occurs when the carboxylic acid generated when the aromatic polyester is decomposed by the heat and moisture absorbed during the molding process reacts with the terminal hydroxyl group, the secondary hydroxyl group, and the terminal epoxy residue of the phenoxy resin. Since the aromatic polyester and the phenoxy resin have a three-dimensional crosslinked structure, the heat resistance and mechanical strength are improved as compared with the case of each resin alone.
• the aromatic polyester resin blended with the phenoxy resin as the matrix resin composition is a polyester having a melting point of 200 ° C. or higher obtained by polycondensation of a dicarboxylic acid compound and a diol.
• raw material carboxylic acid compound examples include terephthalic acid, isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, bis (p-carboxyphenyl) methane, anthracenedicarboxylic acid, 4,4.
• Aromatic dicarboxylic acids such as'-diphenyl ether dicarboxylic acid, 5-tetrabutylphosphonium isophthalic acid, 5-sodium sulfoisophthalic acid, aliphatic dicarboxylic acids such as adipic acid, sebacic acid, azelaic acid, dodecandioic acid, 1,2- Examples thereof include alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, and 1,4-cyclohexanedicarboxylic acid, but these ester-forming derivatives can also be used, and two kinds thereof can be used. The above may be used.
• Examples of the raw material diol include ethylene glycol, propylene glycol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, decamethylene glycol, cyclohexanedimethanol, cyclohexanediol and the like.
• Long-chain glycols with a molecular weight of 200 to 100,000 such as aliphatic or alicyclic glycols having 2 to 20 carbon atoms, polyethylene glycols, poly-1,3-propylene glycols, and polytetramethylene glycols, and 4,4'-dihydroxybiphenyls.
• aromatic polyester resin having a polycondensate of these dicarboxylic acid compounds and diols as a structural unit, polyethylene terephthalate, polyethylene naphthalate, polypropylene terephthalate, polybutylene terephthalate, polypropylene isophthalate, polybutylene isophthalate, polybutylene naphthalate, poly Examples thereof include cyclohexanedimethylene terephthalate, and examples of the copolymer include aromatic polyester resins such as polypropylene isophthalate / terephthalate, polybutylene isophthalate / terephthalate, polypropylene terephthalate / naphthalate, and polybutylene terephthalate / naphthalate.
• a polymer or copolymer having a polycondensate of an aromatic dicarboxylic acid compound and an aliphatic diol as a main structural unit is more preferable in the present invention, and terephthalic acid and naphthalenedicarboxylic acid are more preferable.
• Aromatic polyester resins such as terephthalate, polyethylene isophthalate / terephthalate, polypropylene isophthalate / terephthalate, polybutylene isophthalate / terephthalate, polybutylene terephthalate / decandicarboxylate, polybutylene terephthalate / polytetramethylene glycol are particularly preferable, and polyethylene terephthalate.
• Polybutylene terephthalate, polypropylene terephthalate or polybutylene naphthalate is most preferable.
• the terminal carboxylic acid equivalent of the aromatic polyester resin is preferably 50 eq / t or less, more preferably 40 eq / t or less.
• the terminal carboxylic acid equivalent exceeds 50 eq / t, the hydrolysis resistance and the heat decomposition resistance are lowered.
• the lower limit of the terminal carboxylic acid equivalent is not particularly specified, but may be about 10 eq / t.
• the aromatic polyester resin preferably has a weight average molecular weight (Mw) of 8,000 or more in terms of further improving mechanical properties. Further, when the weight average molecular weight (Mw) is 500,000 or less, the balance between mechanical properties and molding processability is excellent, which is preferable.
• the weight average molecular weight is more preferably 300,000 or less, still more preferably 250,000 or less.
• the melting point of the aromatic polyester is 200 ° C. or higher, preferably 200 to 300 ° C. or lower, and more preferably 220 to 260 ° C. The higher the melting point, the easier it is to improve heat resistance, strength, and rigidity. It drops.
• the melt viscosity is preferably in the range of 100 to 2000 Pa ⁇ s at a temperature equal to or higher than the melting point.
• the aromatic polyester resin used in the present invention may be obtained by a known method, and the production method thereof is not particularly limited.
• the matrix resin composition of the present invention contains a thermoplastic resin other than a phenoxy resin and an aromatic polyester resin, a thermosetting resin such as an epoxy resin, an organic solvent, and a cross-linking agent as long as the effects of the present invention are not impaired.
• a thermoplastic resin other than a phenoxy resin and an aromatic polyester resin a thermosetting resin such as an epoxy resin, an organic solvent, and a cross-linking agent as long as the effects of the present invention are not impaired.
• Inorganic filler, extender pigment, colorant, antioxidant, ultraviolet inhibitor, flame retardant, flame retardant aid and the like may also be blended.
• the total amount of the phenoxy resin and the aromatic polyester resin is 70 weight when the total blending amount of all the resin components is 100 parts by weight. It is desirable that the amount is equal to or more than 80 parts by weight, preferably 80 parts by weight or more.
• the fiber-reinforced plastic molding material of the present invention preferably has a melt viscosity of the resin composition to be the matrix resin before cross-linking of 3000 Pa ⁇ s or less in a temperature range of 250 ° C. to 300 ° C. If the melt viscosity exceeds 3000 Pa ⁇ s, the continuous fiber sheet during the molding process is likely to be sufficiently impregnated with the resin composition, and voids are formed in the obtained molded product to reduce the mechanical strength.
• the melt viscosity is preferably 250 to 3000 Pa ⁇ s, and more preferably 500 to 2500 Pa ⁇ s.
• the melt viscosity of the resin composition to be the matrix resin is measured using a leometer while raising the temperature at a constant rate, but since a phenoxy resin having no melting point is blended until the crosslinking reaction occurs.
• the melt viscosity decreases with temperature and increases once the cross-linking reaction starts. Therefore, the melt viscosity of the resin composition to be the matrix resin refers to the melt viscosity until the cross-linking reaction starts.
• the resin composition to be the matrix resin forms a three-dimensional crosslinked structure by causing a crosslinking reaction between the phenoxy resin and the aromatic polyester when it receives a certain thermal history. This is confirmed by measuring the melt viscosity of the resin composition while keeping the temperature constant with a rheometer, and the melt viscosity once lowered increases with the start of the crosslinking reaction.
• the melt viscosity of the resin composition is measured while being held at 270 ° C., the melt viscosity once melts to show the minimum value, then gently rises to the same temperature (270). It is preferable that the melt viscosity increases from the minimum value to 100% or more by holding at (° C.) for, for example, 15 minutes or more.
• the melt viscosities after holding for 5 minutes and holding for 20 minutes at 270 ° C. were measured, and the cross-linking reaction was confirmed by increasing the melt viscosity from the minimum value.
• the rate of the cross-linking reaction is slow at the initial stage, and a slight change in viscosity due to cross-linking is observed at about 5 min at 270 ° C.
• the melt viscosity was set to the minimum value.
• the fiber-reinforced plastic molding material of the present invention uses a continuous fiber sheet made of reinforcing fibers as a base material, and the surface thereof is impregnated with a resin composition to be a matrix resin composition after molding. At this time, as long as the matrix resin composition is evenly present on the entire surface of the continuous fiber sheet regardless of whether it is impregnated or semi-impregnated, it may be in a state of completely covering the continuous fiber sheet or in a state of maintaining a certain degree of air permeability. However, the latter state is preferable because the air between the layers and the generated gas are easily released during the molding process.
• the continuous fiber sheet is preferably one in which fibers called filaments constituting the continuous fiber sheet are opened, and the basis weight is preferably in the range of 20 to 600 g / m 2. If the basis weight is less than 20 g / m 2 , the desired mechanical properties cannot be obtained because the number of reinforcing fibers in the molded product is small. If it exceeds 600 g / m 2 , it becomes difficult to sufficiently impregnate the inside of the reinforcing fiber base material with the resin, which is not preferable.
• the basis weight is more preferably 25 to 500 g / m 2 , and most preferably 40 to 250 g / m 2 .
• the content of the sizing agent and the coupling agent, which are surface treatment agents, is preferably 0.1 to 10 parts by weight, more preferably 0.5 to 6 parts by weight, based on 100 parts by weight of the continuous fiber sheet.
• the content of the sizing agent and the coupling agent is 0.1 to 10 parts by weight, the wettability with the matrix resin composition and the handleability are more excellent.
• the method of impregnating the continuous fiber sheet with the resin composition can be performed by using a conventionally known method, but a method of laminating a film of the resin composition to be a matrix resin on the continuous fiber sheet, or processing into particles or threads. A method of adhering the resin to the continuous sheet base material is preferable.
• the method of attaching the film of the resin composition to the continuous fiber sheet is to heat and pressurize the film of the resin composition produced by a conventionally known method such as the T-die method or the inflation method together with the continuous fiber sheet with a press machine.
• a fiber reinforced plastic molding material is obtained.
• a UD material is used for the continuous fiber sheet, it is possible to manufacture rolls, toes and rolls using a roll press or a belt press machine, which is a preferable method.
• the thickness of the resin composition film to be the matrix resin is appropriately adjusted according to the desired fiber volume content, but may be in the range of approximately 20 to 200 ⁇ m.
• an electrostatic coating method, a fluidized bed method, and a suspension method can be mentioned as the main construction methods.
• the electrostatic coating method and the fluidized bed method are methods suitable for thermoplastic resins such as aromatic polyester resins and phenoxy resins used in the matrix resin composition of the present invention, and the steps are simple and productive. Is preferable because it is good.
• the average particle size of the fine powder of the raw material resin composition used in the powder coating method is preferably in the range of, for example, 20 to 150 ⁇ m. If the average particle size of the fine powder exceeds 150 ⁇ m, the adhesion rate to the continuous fiber sheet decreases. On the other hand, if the average particle size of the fine powder is less than 10 ⁇ m, the particles are likely to scatter too easily and the adhesion efficiency is lowered, and the fine powder of the raw material resin suspended in the atmosphere may cause deterioration of the working environment. There is.
• the pulverization of the raw material resin is preferably performed by a pulverizer / mixer such as a low temperature drying pulverizer (Sentri Dry Mill), but is not limited thereto. Further, when crushing the raw material resin, a plurality of components as raw materials may be crushed and then mixed, or a plurality of components may be mixed in advance and then crushed.
• the amount of the raw material resin fine powder adhered to the continuous fiber sheet is preferably in the range of, for example, 20 to 50%, preferably 25 to 45%. The range is more preferable, and the range of 25 to 40% is further preferable. If the RC exceeds 50%, the mechanical properties such as the tensile and bending elastic modulus of the fiber reinforced plastic molded body (FRP) will decrease, and if it exceeds 20%, the amount of the raw material resin adhered will be extremely small. There is a concern that the impregnation of the raw material resin into the inside will be insufficient, and both the thermal and mechanical properties will be low.
• FRP fiber reinforced plastic molded body
• heat treatment is performed to adhere (fix) the powder of the resin composition to be the matrix resin to the continuous fiber sheet.
• the heat treatment conditions for adhesion are not particularly limited as long as the resin composition does not start cross-linking, but heat treatment is performed at a temperature of 200 to 280 ° C. for about 10 seconds to 3 minutes using a heating furnace or the like. good.
• the treatment temperature is preferably 220 to 270 ° C, more preferably 230 to 270 ° C. If the heat treatment temperature exceeds the upper limit, the curing reaction may proceed, and if it falls below the lower limit, heat fusion becomes insufficient, and the matrix resin fine powder may fall off or fall off during the handling work of the FRP molding material.
• this step is a heat treatment performed to fix the resin composition to be the matrix resin to the continuous fiber sheet, it is not limited to the powder coating method. Further, at the same time as this step, the surface of the fiber-reinforced plastic molding material may be smoothed by a calendering process using a roll or the like. If this heat treatment is not performed, the matrix resin will fall off during molding. Therefore, by performing the heat treatment in a shorter time than in the press molding, the phenoxy resin or the aromatic polyester resin can be heat-sealed and fixed to the continuous fiber sheet without reacting the cross-linking agent with the resin.
• the fiber-reinforced plastic molding material of the present invention is not only actually used as a prepreg of a UD material or a cloth material in which a continuous fiber sheet is impregnated with a resin composition, but also, for example, two prepregs of a UD material are laminated to form one sheet.
• Post-processing may be performed like a molding material called a bias sheet.
• a thermoplastic resin film may be arranged between the layers, and when two prepregs are used as one sheet, in addition to fusion by heat treatment to the extent that cross-linking does not occur, stitch yarn is used. May be physically integrated using.
• the fiber-reinforced plastic molding material of the present invention is heat-pressed using a heat press or the like to melt the resin composition and impregnate the continuous fiber sheet to obtain a fiber-reinforced plastic molded body. Further, if a mold is used during the heat and pressure processing, the molding process into a predetermined shape can be performed at the same time.
• the pressure heat treatment is performed by setting a fiber reinforced plastic molding material in a heat press machine in which a hot plate is heated to a predetermined temperature in advance, and the material heated to a predetermined temperature in advance is quickly pressure-molded at a low temperature. It can also be set on a machine for processing.
• the heat-pressurization treatment is performed at a temperature in the range of about 200 ° C. to 350 ° C., which is equal to or higher than the melting point of the aromatic polyester, in order to completely melt the fine powder of the raw material resin composition and impregnate the entire continuous fiber sheet. It is preferable, and within this temperature range, the temperature of the melting point (Tm) of the aromatic polyester resin actually blended as the resin composition + 10 to 60 ° C. is more preferable. If the upper limit temperature is exceeded, excessive heat may be applied and the resin may be decomposed, and if the temperature is lower than the lower limit temperature, the continuous fiber sheet may be insufficiently impregnated due to the high melt viscosity. Not only that, the cross-linking reaction between the aromatic polyester resin and the phenoxy resin does not occur, so that a cured product (fiber reinforced plastic molded product) having desired strength and heat resistance cannot be obtained.
• Tm melting point
• the pressure of the heat and pressurization treatment is preferably, for example, 3 MPa or more, and more preferably in the range of 3 to 5 MPa. If it exceeds the upper limit, excessive pressure is applied, which may cause deformation or damage, and if it is lower than the lower limit, the impregnation property of the continuous fiber sheet deteriorates.
• the heat and pressure treatment time is preferably at least 5 minutes or more, and more preferably within the range of 5 to 30 minutes.
• a heat-pressurization treatment for 15 minutes or more, but heat-addition is performed by performing an arbitrary heat treatment such as post-cure.
• the pressure processing time can also be shortened.
• post-cure it is preferable to carry out post-cure at the same temperature as during heating and pressurization (for example, 280 ° C.) over a period of about 10 to 30 minutes.
• the fiber reinforced plastic plate material is first processed by heat molding for a short time (10 min or less), and then the fiber reinforced plastic plate material is subjected to a temperature equal to or higher than the melting point (Tm) of the aromatic polyester resin. It can also be shaped into a desired shape by a heating press at a temperature of 270 ° C. or higher, preferably for a time of 15 minutes or longer.
• the fiber-reinforced plastic molded product of the present invention preferably has a fiber volume content (Vf) of the continuous fiber sheet in the range of 40 to 65%.
• Vf is adjusted depending on the use of the fiber reinforced plastic molded product, but is more preferably 45 to 65%, still more preferably 45 to 60%. If Vf exceeds 65%, the amount of matrix resin tends to be insufficient, and the strength of the fiber-reinforced plastic molded product is rather lowered. Further, when Vf is 40% or less, the reinforcing effect of the continuous fiber sheet is reduced.
• the FRP molded product obtained from the fiber-reinforced plastic molding material of the present invention has both good moldability of the phenoxy resin and heat resistance of the aromatic polyester resin by blending the phenoxy resin and the aromatic polyester resin, and further by thermal cross-linking. It is also possible to express a three-dimensional network structure. In particular, the crosslinked cured product hardly deforms even when it receives heat higher than the melting point of the aromatic polyester resin used, and the rigidity at high temperature is greatly improved. It can be widely and suitably used not only as parts and parts but also as molded parts for automobiles and industrial equipment that require higher heat resistance such as engine covers.
• test and measurement methods for various physical properties are as follows.
• melt viscosity of resin composition [Melting viscosity of resin composition] Using a rheometer (MCR302 manufactured by Antonio Par), a sample processed into a film of 150 mm square and 0.4 mm thick at 265 ° C. for 60 seconds was sandwiched between parallel plates and up to 270 ° C. at 50 ° C./ After raising the temperature in min, while maintaining the temperature at 270 ° C as it is, the minimum melt viscosity and 270 ° C under the conditions of frequency: 1 Hz, swing angle: 0.5%, normal force (normal force): 0.1 N. The melt viscosity was measured. In Tables 1 and 2, the melt viscosities are numerical values of melt viscosities of 5 min and 20 min after reaching 270 ° C.
• melt viscosity As the melt viscosity, the minimum melt viscosity when held for 5 minutes after reaching 270 ° C. was set as the minimum value.
• the amount of change in melt viscosity is the amount of change in melt viscosity at a temperature of ⁇ 20 ° C. at the melting point of the aromatic polyester resin (for example, polyethylene terephthalate is 250 ° C.).
• Amount of change in melt viscosity [(melt viscosity at 270 ° C)-(melt viscosity at 230 ° C)] / (270 ° C-230 ° C)
• the springback of the molded product was determined by the amount of change in the thickness of the molded product at 25 ° C. and the molded product after receiving a heat history of 200 ° C. for 30 minutes in an atmospheric oven. For the thickness measurement, the average value obtained at three points using a micrometer was used, and the springback amount was calculated by the following formula.
• Springback Mold size thickness after heat history / Mold thickness at 25 ° C
• Example 1 20 parts by weight of phenoxy resin YP-50S and 80 parts by weight of polyethylene terephthalate (PET) resin NEH-2070 were prepared, and powders having an average particle size D50 of 80 ⁇ m were crushed and classified, respectively, into a dry powder mixer (Aichi Electric Co., Ltd.).
• the matrix resin composition powder was prepared by dry blending with a locking mixer manufactured by the same company.
• the prepared matrix resin composition powder was used as a reinforcing fiber base material using a plain-woven continuous fiber sheet made of opened carbon fibers (manufactured by Sakai Obex, SA32021) as a reinforcing fiber base material, with an electric charge of 60 kV and a sprayed air amount in an electrostatic field. Under the condition of 60 L / min, powder coating was performed on both sides of the sheet so that the Vf after molding was 60%. Then, the resin composition was heat-fused to carbon fibers by heating and melting at 270 ° C. for 20 seconds in an oven to prepare a CFRP prepreg (fiber reinforced plastic molding material) having a thickness of 0.9 mm.
• CFRP prepreg fiber reinforced plastic molding material
• Example 2 A CFRP prepreg was prepared in the same manner as in Example 1 except that the phenoxy resin YP-50S was 50 parts by weight and the PET resin was 50 parts by weight. The results are shown in Table 1.
• Example 3 A CFRP prepreg was prepared in the same manner as in Example 1 except that the phenoxy resin YP-50S was 70 parts by weight and the PET resin was 30 parts by weight. The results are shown in Table 1.
• Example 4 A CFRP prepreg was prepared in the same manner as in Example 1 except that the phenoxy resin YP-50S was 80 parts by weight and the PET resin was 20 parts by weight. The results are shown in Table 1.
• Example 5 The CFRP molded product prepared in Example 2 was sandwiched between two 1.6 mm thick SUS plates, and post-cured in an oven at 270 ° C. for 30 minutes. The CFRP molded product was allowed to cool while being sandwiched between SUS plates until it returned to room temperature, and after allowing it to cool, measurements were taken at various points. The results are shown in Table 1.
• Example 6 A phenoxy resin, 50 parts by mass, and 50 parts by mass of an aromatic polyester resin were blended and melt-kneaded with a biaxially rotating twin-screw extruder (set temperature: 280 ° C.) having a screw diameter of 26 mm to pelletize. The pellets are then crushed and classified into powders having an average particle size D50 of 80 ⁇ m, and then a plain-woven continuous fiber sheet made of opened carbon fibers (manufactured by Sakai Obex, SA32021) is used as a reinforcing fiber base material.
• a biaxially rotating twin-screw extruder set temperature: 280 ° C.
• Example 7 A CFRP prepreg was prepared in the same manner as in Example 6 except that 80 parts by mass of a phenoxy resin and 20 parts by mass of an aromatic polyester resin were blended. A plurality of CFRP prepregs obtained were laminated and then pressed at 2 MPa for 15 minutes with a press machine heated to 270 ° C. to prepare a CFRP molded body, and after cooling, the mechanical strength was measured. The results are shown in Table 2.
• Comparative Example 1 After crushing and classifying the phenoxy resin into a powder having an average particle diameter D50 of 80 ⁇ m, the continuous carbon fiber sheet is powder-coated in the same manner as in Example 6, and then heat-sealed (temperature is 200 ° C.) to CFRP. A prepreg was prepared. A plurality of CFRP prepregs obtained were laminated and then pressed at 5 MPa for 15 minutes with a press machine heated to 240 ° C. to prepare a CFRP molded body, and after cooling, the mechanical strength was measured. The results are shown in Table 2.
• Comparative Example 2 After crushing and classifying the aromatic polyester resin to obtain a powder having an average particle diameter D50 of 80 ⁇ m, the continuous carbon fiber sheet is powder-coated in the same manner as in Example 6, and then heat-sealed (temperature is 270 ° C.). , CFRP prepreg was prepared. A plurality of CFRP prepregs were laminated and then heated to 270 ° C. to prepare a CFRP molded body by pressing at 2 MPa for 15 minutes. After cooling, the mechanical strength (breaking point stress and elastic modulus) was obtained. ) was measured. The results are shown in Table 2.
• the CFRP (fiber reinforced plastic molding material) of the example has a deflection temperature under load almost equal to or higher than that of Comparative Example 1 on the excess side of the phenoxy resin regardless of the production method (dry blend, melt mixing) of the resin composition.
• the rapid change in the melt viscosity before and after the melting point of the aromatic polyester is suppressed, so that the processing is good.
• Example 5 when the phenoxy resin and PET are blended in substantially equal amounts, the deflection temperature under load can be further improved by the effect of the cross-linking reaction by post-cure.
• the fiber reinforced plastic molding material of the present invention is useful not only for electronic / electrical equipment parts and automobile parts, but also for composite materials in fields such as aerospace where higher performance is required.

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• 2021
  • 2021-03-29 WO PCT/JP2021/013214 patent/WO2021200793A1/ja active Application Filing
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