Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G59/00—Polycondensates containing more than one epoxy group per molecule; Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups
  • C08G59/18—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G59/00—Polycondensates containing more than one epoxy group per molecule; Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups
  • C08G59/18—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing
  • C08G59/20—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing characterised by the epoxy compounds used
  • C08G59/32—Epoxy compounds containing three or more epoxy groups
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G59/00—Polycondensates containing more than one epoxy group per molecule; Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups
  • C08G59/18—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing
  • C08G59/20—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing characterised by the epoxy compounds used
  • C08G59/32—Epoxy compounds containing three or more epoxy groups
  • C08G59/38—Epoxy compounds containing three or more epoxy groups together with di-epoxy compounds
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G59/00—Polycondensates containing more than one epoxy group per molecule; Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups
  • C08G59/18—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing
  • C08G59/40—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing characterised by the curing agents used
  • C08G59/50—Amines
  • C08G59/5033—Amines aromatic
• • 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
  • C08J5/24—Impregnating materials with prepolymers which can be polymerised in situ, e.g. manufacture of prepregs
  • C08J5/241—Impregnating materials with prepolymers which can be polymerised in situ, e.g. manufacture of prepregs using inorganic fibres
  • C08J5/243—Impregnating materials with prepolymers which can be polymerised in situ, e.g. manufacture of prepregs using inorganic fibres using carbon fibres
• • 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
  • C08J5/24—Impregnating materials with prepolymers which can be polymerised in situ, e.g. manufacture of prepregs
  • C08J5/249—Impregnating materials with prepolymers which can be polymerised in situ, e.g. manufacture of prepregs characterised by the additives used in the prepolymer mixture
• • 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
  • C08J2363/00—Characterised by the use of epoxy resins; Derivatives of epoxy resins
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/249921—Web or sheet containing structurally defined element or component
  • Y10T428/249924—Noninterengaged fiber-containing paper-free web or sheet which is not of specified porosity
  • Y10T428/24994—Fiber embedded in or on the surface of a polymeric matrix
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/31504—Composite [nonstructural laminate]
  • Y10T428/31511—Of epoxy ether

Definitions

• the present invention relates to an epoxy resin composition that is useful for production, by resin transfer molding (RTM) in particular, of high performance fiber reinforced composite material, and also relates to a molding method that uses said resin composition.
• RTM resin transfer molding
• Fiber reinforced composite materials that consist of reinforcing fiber, such as glass fiber, carbon fiber and aramid fiber, and matrix resin, such as unsaturated polyester resin, vinyl ester resin, epoxy resin, phenol resin, cyanate ester resin and bismaleimide resin, are lightweight but high in strength, rigidity, shock resistance, fatigue resistance and other mechanical properties, in addition to being high in corrosion resistance, and accordingly have been used in aircraft, spacecraft, automobiles, railroad vehicles, ships, construction material, sporting goods, and many other materials in different fields.
• fiber reinforced composite materials composed of continuous fiber are generally used to produce high performance products, with carbon fiber and thermosetting resins, epoxy resin among others, being frequently used as reinforcing fiber and matrix resin, respectively.
• VaRTM vacuum assisted resin transfer molding
• thermosetting resins have been applied to RTM, but in particular, epoxy resin and bismaleimide resin are widely used in the field of aircraft manufacturing where high performance materials are essential, with particular importance attached to epoxy resin because of its high cost performance.
• An epoxy resin composition to be used in RTM consists mainly of epoxy resin and a hardener, with other additives being added as required.
• Epoxy resin materials used as main component of an epoxy resin composition for RTM include general-purpose glycidyl ether of bisphenol A, general-purpose glycidyl ether of bisphenol F, novolac glycidyl ether as shown in U.S. Pat. No. 5,942,182A, glycidylamine-type epoxy resin as shown in Japanese Patent Laid-Open Publication (Kokai) HEI 03-050244, diglycidyl anilines as shown in Japanese Patent Laid-Open Publication (Kokai) HEI 03-050242, epoxy resin with a fluorine backbone as shown in U.S. Pat. No.
• Known hardeners generally used with epoxy resin in RTM processes include aliphatic polyamines, aromatic polyamines, acid anhydrides, and Lewis acid complexes.
• Hardeners widely used with an epoxy resin composition for producing fiber reinforced composite material in the field of aircraft manufacturing include, among others, aromatic polyamine, which is also used frequently as resin for RTM in this field.
• Aromatic polyamine materials known to be widely used as resin for RTM include diethyl toluenediamines as shown in U.S. Pat. No. 5,688,877A and WO02/02666A1, aminobenzoic acid esters as shown in Japanese Patent Laid-Open Publication (Kokai) HEI 05-320480, 4,4′-diaminodiphenyl sulfones as shown in Japanese Patent Laid-Open Publication (Kokai) HEI 09-137044, alkyl derivatives of diaminodiphenyl methane as shown in WO02/02666A1, and aromatic diamines with a fluorene backbone as shown in U.S. Pat. No.
• liquid epoxy resin compositions for filament winding that consist of glycidylamine type epoxy resin and diglycidyl aniline, plus either diaminodiphenyl sulfone or diaminodiphenyl methane, are disclosed in Japanese Patent Laid-Open Publication (Kokai) SHO 63-077926.
• Some of said diethyl toluenediamines, aminobenzoic acid esters, and alkyl derivatives of diaminodiphenyl methanes are liquid, while said diaminodiphenyl sulfones, diaminodiphenyl methanes, and aromatic diamines with a fluorene backbone are solid at room temperature.
• a one part type resin product is a composition that comprises both epoxy resin and aromatic polyamine.
• said product is injected after being heated to an appropriate temperature. Since aromatic polyamines are relatively low in reactivity, compositions that consist of epoxy resin and aromatic polyamine can be stored for a relatively long period of time.
• a two parts type resin product consists of an epoxy resin based liquid and an aromatic amine based liquid, which are stored separately and mixed to provide a resin composition for molding.
• Fiber reinforced composite materials to be used in the field of aircraft manufacturing are generally required to be high in heat resistance.
• Cured epoxy resin is amorphous and has a glass transition temperature. Above the glass transition temperature, the rigidity of cured resin decreases greatly, resulting in deterioration of mechanical properties of the fiber reinforced composite material. Accordingly, the glass transition temperature of cured resin serves as an indicator of the heat resistance of the resulting fiber reinforced composite material.
• the glass transition temperature of cured thermosetting resin correlates with the highest temperature found in the heat history of the curing process. In the aerospace industry, curing conditions are frequently set up so that the maximum temperature during the process is about 180° C. ° C.
• Suitable catalysts for this purpose include BF 3 •amine complexes as shown in WO01/92368A1, sulfonium salts as shown in U.S. Pat. No. 4,554,342A and Japanese Patent Laid-Open Publication (Kokai) 2002-003581, alkyl esters of strong acids as shown in U.S. Pat. No. 5,688,877A, and polyphenolic compounds as shown in U.S. Pat. No. 4,593,056A.
• a two parts type epoxy resin composition is preferred when a catalyst is used. It is because, while the shelf life a one part type epoxy resin composition shortens if a catalyst is added, such a problem can be avoided if a two parts type epoxy resin composition is used. Cured products of epoxy resin compositions designed for production of fiber reinforced composite material to be used in the aerospace industry are required to have many good properties. In addition to the above-mentioned high glass transition temperatures, they should preferably be high in elastic modulus, high in toughness, poor in the glass temperature decrease caused by water absorption (or high in resistance to moist heat), and small in the coefficient of linear expansion.
• Such aromatic polyamines as 4,4′-diaminodiphenyl sulfone and 3,3′-diaminodiphenyl sulfone can serve to produce cured products with such good properties as small coefficient of linear expansion and high heat resistance, and therefore they are widely used as hardeners to cure epoxy resin compositions for prepreg production in the aerospace industry.
• diaminodiphenyl sulfones are solid with a high melting point, they are not used in two parts type epoxy resin composition products. It is not impossible in theory to design a batch comprising a solid hardener, but this is not practical because a continuous mixer cannot be applied. Thus, difficulty of using high-performance components has been a major problem with conventional two parts type epoxy resin composition products.
• Another serious problem with conventional epoxy resin composition products for RTM is trade-off between low viscosity and good properties of cured products. Injection under a relatively high pressure can be performed in the RTM process which uses a closed mold, but the VaRTM process needs a low viscosity at the time of injection because the process uses atmospheric pressure for injection, requiring a considerably low viscosity to carry out impregnation. If precure at 80° C.-140° C. is assumed, furthermore, the inlet temperature has to be set to 40° C.-90° C. An epoxy resin composition to be used should preferably have a viscosity of 500 MPa ⁇ s or less at an inlet temperature in this temperature range.
• an epoxy resin composition for RTM that has an initial viscosity of 500 MPa ⁇ s or less at an inlet temperature in the range of 40° C.-90° C., can be precured at 80° C.-140° C., and can form a cured products that are high in glass transition temperature, elastic modulus and toughness while being small in the glass temperature decrease caused by water absorption and also small in the coefficient of linear expansion.
• the purpose of the present invention is to provide a liquid epoxy resin composition for low cost production of high performance fiber reinforced composite material, that has a low viscosity at relatively low temperatures, and that after being cured, the cured product is high in glass transition temperature, elastic modulus and toughness while being small in the glass temperature decrease caused by water absorption and also small in the coefficient of linear expansion; and to provide a method to produce fiber reinforced composite material therefrom.
• epoxy resin is generally used to refer to either a category of thermosetting resins or a category of chemical substances having two or more 1,2-epoxy groups within the. molecule, but the latter definition should be applied to the following descriptions.
• epoxy resin composition refers to a composition consisting of an epoxy resin and a hardener, as well as other additives as required.
• the first epoxy resin composition of the present invention comprises the following components (1)-(3) as essential components, their mixing ratios meeting the following conditions (I)-(IV), and component (3) being dissolved homogeneously:
• Component (1) epoxy resin that is liquid at room temperature
• Component (2) aromatic polyamine that is liquid at room temperature
• Component (3) diaminodiphenylsulfone
• component (2) does not contain component (3).
• Said epoxy resin composition should preferably be produced by mixing the following two liquids.
• Liquid-(A1) a liquid that consists of component (1).
• Liquid (B1) a liquid that consists of components (2) and (3), and contains component (3) dissolved homogeneously.
• Liquid (B) should preferably be free of precipitation of component (3) after being stored for 30 days at 5° C.
• component (3) should preferably consist of 3,3′-Diaminodiphenylsulfone, and 4,4′-diaminodiphenylsulfone. This is because a solution of the two isomers is much stabler than a solution of only one isomer.
• Component (2) should preferably be diethyl toluenediamine, which is low in viscosity, because it serves to lower the viscosity of the composition.
• said epoxy resin composition should, after being cured for two hours at 180° C., preferably have a glass transition temperature of 170° C. or more and a coefficient of linear expansion of 7 ⁇ 10 ⁇ 5 K ⁇ 1 or less in the temperature range of 30° C. to 160° C.
• Fiber reinforced composite material can be high in tensile strength if its coefficient of linear expansion is in the above-mentioned range.
• said epoxy resin composition should preferably have an initial viscosity of 1-500 MPa ⁇ s at 80° C., and after being left to stand for one hour at 80° C., should preferably have a viscosity not more than four times the initial viscosity. Moreover, to enable precure at a relatively low temperature, material produced by curing for two hours at 130° C. should preferably have a glass transition temperature of 120° C. or more.
• said epoxy resin composition should preferably contain an accelerator selected from the group of strong acid ester, onium salt, Lewis acid•amine complex, and polyphenol.
• the second epoxy resin composition of the present invention is an epoxy resin composition for production of fiber reinforced composite material, that contains at least the following components (4)-(6), forms a cured product with a theoretical molecular weight between crosslinking points in the range of 250-350 g/mol, and has an initial viscosity at 80° C. of 1-500 MPa ⁇ s.
• the molecular weight between crosslinking points is defined as the weight of the entire cured epoxy resin divided by the number of crosslinking points contained in the entire cured epoxy resin.
• a cured product should have a theoretical molecular weight between crosslinking points to be in said range, in order to be high in both heat resistance and toughness.
• component (4) should preferably be at least one selected from the group of N,N,N′,N′-tetraglycidyl-4,4′-diaminodiphenyl methane, N,N,O-triglycidyl-m-aminophenol, N,N,O-triglycidyl-p-aminophenol, alkyl-substituted derivatives of the foregoing substances, and N,N,N′,N′-tetraglycidyl-m-xylene diamine.
• Suitable epoxy resins as component (5) include polyglycidyl ethers in the form of a condensation product of phenol or a substituent derivative thereof and dicyclopentadiene, dihydroxynaphthalene diglycidyl ether, diglycidyl ether of dihydroxybiphenyl or its substituent derivative, diglycidyl ether of 9,9-bis(4-hydroxyphenyl)fluorine, and polyglycidyl ether of phenol aralkyl resin.
• Said epoxy resin compositions should, after being cured for two hours at 180° C., preferably have a flexural modulus of 3.3-4.5 GPa at 25° C. and a glass transition temperature of 170° C. or more.
• the third epoxy resin composition of the present invention is an epoxy resin composition for production of fiber reinforced composite material, that consists of a polyglycidyl ether of phenol aralkyl resin, and a polyamine.
• the fourth epoxy resin composition of this invention is an epoxy resin composition for production of fiber reinforced composite material, that consists of an epoxy resin and an aromatic polyamine, has an initial viscosity is in the range of 1-500 MPa ⁇ s at 80° C., and after being cured for two hours at 180° C., forms a cured product having a glass transition temperature of 130° C. or more after being immersed in boiling water for 48 hours.
• Said epoxy resin composition should, after being cured for two hours at 180° C., preferably have a flexural modulus of 2.3 GPa or more at 82° C.
• the resulting fiber reinforced composite material comprising a cured product of said epoxy resin composition as matrix can have a high compressive strength in wet heat.
• the fifth epoxy resin composition of the present invention is characterized in that it is produced by mixing the following two liquids.
• Liquid (A3) the following component (9) and component (10).
• Liquid (B3) a liquid that consists of aromatic polyamine.
• Component (9) at least one epoxy resin selected from the group of N,N,N′,N′-tetraglycidyl-4,4′-diaminodiphenyl methane and alkyl-substituted derivatives thereof.
• Component (10) at least one epoxy resin selected from the group of N,N-diglycidyl aniline and alkyl-substituted derivatives thereof.
• components (9) and (10) should preferably account for 30-90 wt % and 10-30 wt %, respectively, of the entire epoxy resin.
• Said epoxy resin composition is characterized in that, after being cured, the cured product suffers little glass transition temperature decrease due to water absorption.
• the production method for fiber reinforced composite material according to the present invention is characterized in that reinforcing fiber is impregnated with one of said epoxy resin compositions and then cured by heating.
• the production method for fiber reinforced composite material according to the present invention should preferably consist of impregnating reinforcing fiber with one of said epoxy resin compositions at a temperature in the range of 40-90° C., followed by precure at a temperature in the range of 80° C.-140° C. and aftercure at a temperature in the range of 170-190° C.
• the fiber reinforced composite material of the present invention consists of a cured product of said epoxy resin composition, and reinforcing fiber.
• said reinforcing fiber should preferably account for 50-85% by volume.
• the epoxy resin composition for production of fiber reinforced composite material according to the present invention is a liquid epoxy resin composition that consists of epoxy resin and aromatic amine.
• the epoxy resin composition according to the present invention should preferably be produced by mixing the following two liquids.
• the epoxy resin composition for production of fiber reinforced composite material according to the present invention should preferably have an initial viscosity in the range of 1-500 mPa ⁇ s at 80° C. Since this requires a long pot life, said composition after being left to stand for one hour at 80° C. should preferably have a viscosity not more than four times the initial viscosity, more preferably a viscosity in the range of 1-1000 MPa ⁇ s after being left to stand for one hour at 80° C.
• Aromatic polyamine to be used in the epoxy resin composition according to the present invention may be a single component material that is liquid at room temperature, or may be a mixture. Said mixture may contain, as a component, an aromatic amine that is solid at room temperature, but the mixture should be liquid at room temperature.
• room temperature is defined as 25° C.
• liquid and solid used hereinafter refer to properties at 25° C. unless otherwise specified.
• Liquid aromatic polyamines suitable for production of epoxy resin according to the present invention include: diethyl toluenediamine (a mixture consisting mainly of 2,4-diethyl-6-methyl-m-phenylenediamine and 4,6-diethyl-2-methyl-m-phenylenediamine),
• diethyl toluenediamine is preferred most because it is low in viscosity and can form a cured product with preferred properties including glass transition temperature.
• the epoxy resin composition according to the invention should preferably contain diaminodiphenylsulfone as a solid aromatic polyamine component.
• Diaminodiphenylsulfone particularly the major isomers of 4,4′-diaminodiphenylsulfone, and
• [0071] has preferred features such as ability to form a cured product with a high heat resistance and a small coefficient of linear expansion.
• Diaminodiphenylsulfone is easily precipitates into crystal as it is left to stand for a long time at a low temperature, even after being mixed with a liquid aromatic polyamine at a high temperature.
• 3,3′-diaminodiphenylsulfone is slower in crystallization.
• a liquid mixture consisting of the two isomers and a liquid aromatic polyamine is preferred because it is much slower in crystallization than a mixture consisting of one isomer and a liquid aromatic polyamine.
• the epoxy resin composition according to the invention may contain, as an optional component, a solid aromatic polyamine other than diaminodiphenylsulfones.
• Preferred solid aromatic polyamines include: 4,4′-diaminodiphenyl methane,
• Bis(4-(3-aminophenoxy)phenyl)sulfone is particularly preferred because it is slow in crystallization when used ion combination with 4,4′-diaminodiphenylsulfone and 3,3′-diaminodiphenylsulfone.
• the epoxy resin composition according to the invention may contain an aliphatic polyamine as an optional component.
• liquid aromatic polyamine and diaminodiphenylsulfone combined should preferably account for 70-100 wt % of the entire polyamine.
• diaminodiphenylsulfone should preferably account for 25-60 wt % of the entire polyamine. Good features such as high coefficient of linear expansion are not developed if the proportion of diaminodiphenylsulfone is less than 25 wt %, while crystallization can take place easily if it exceeds 60 wt %.
• the epoxy resin composition according to the invention should, after being cured for two hours at 180° C., preferably have a coefficient of linear expansion of 7 ⁇ 10 ⁇ 5 K ⁇ 1 or less in the range of 30° C. to 160° C.
• An epoxy resin to be used for production of the epoxy resin composition according to the invention may be a single component material that is liquid at room temperature, but also may be a mixture. Said mixture may contain an epoxy resin that is solid at room temperature, but the mixture itself should be liquid at room temperature.
• the epoxy resin composition according to the invention should preferably contain at least one aromatic epoxy resin.
• the epoxy resin composition according to the invention should preferably be used in combination with an aromatic epoxy resin with tri- or higher functionality and another aromatic epoxy resin with di- or higher and lower than tri-functionality.
• Preferred epoxy resins with tri- or higher functionality include:
• Preferred di-functional epoxy resins include:
• epoxy resin having an oxazolidone ring which is produced by reaction of two molecules of a diglycidyl ether of bisphenol A with one molecule of tolylene diisocyanate (solid at room temperature),
• Epoxy resins having di- or higher and lower than tri-functionality include condensation products of formaldehyde and phenol or its substituent derivative, that is, novolac polyglycidyl ether (normally solid at room temperature).
• R 1 and R 2 denote a hydrogen atom, an alkyl group having 1-8 carbon atoms, or a halogen atom
• n denotes a real number of 0 or more and less than 1
• polyglycidyl ethers in the form of a condensation product of dicycolpentadiene and phenol or its substituent derivative (normally solid at room temperature)
• R 1 and R 2 denote a hydrogen atom, an alkyl group having 1-8 carbon atoms, or a halogen atom
• n denotes a real number of 0 or more and less than 1
• R 1 , R 2 , R 3 and R 4 denote a hydrogen atom, an alkyl group having 1-8 carbon atoms, or a halogen atom
• m and n denote an integer of 1-4 and a real number of 0 or more and less than 1, respectively.
• the epoxy resin composition according to the invention can contain, as an optional component, an aliphatic epoxy resin, in addition to said aromatic epoxy resins.
• Preferred aliphatic epoxy resins include 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, bis(2,3-epoxycyclopentyl)ethers, diglycidyl hexahydrophthalate, and neopentylene glycol diglycidyl esters.
• the reactivity will be low, however, if the mixing ratio of 3,4-epoxycyclohexylmethyl-3,4-epoxy-cyclohexanecarboxylate, which contains an epoxycyclohexane ring, or a bis(2,3-epoxycyclopentyl)ether is large.
• One of the purposes of the present invention is to allow the resulting cured product to have a sufficiently high glass transition temperature in addition to sufficiently high elongation and toughness.
• the epoxy resin according to the invention should preferably have a glass transition temperature of 170° C. or more, more preferably 180° C. or more.
• Cured products of the epoxy resin composition obtained by curing for two hours at 180° C. should preferably have an elongation of 4% or more, more preferably 5% or more.
• said cured products of the epoxy resin composition according to the invention should preferably have a theoretical molecular weight between crosslinking points, á, in the range of 250-350 g/mol.
• the theoretical molecular weight between crosslinking points, á is defined as the weight of the cured epoxy resin, W, divided by the theoretical number of crosslinking points in the cured epoxy resin, and it is known to be inversely proportional to the crosslink density of the cured product and negatively correlated with the glass transition temperature and elastic modulus.
• the resulting cured epoxy resin will be so high in crosslink density, possibly making said cured epoxy resin low in elongation and toughness, though high in heat resistance, which in turn will result in fiber reinforced composite material low in tensile strength, compression strength after impact, and fatigue resistance. If the theoretical molecular weight between crosslinking points is larger than 350 g/mol, on the other hand, the crosslink density will be too small, possibly making the resulting cured epoxy resin low in glass transition temperature, which in turn will result in fiber reinforced composite material with poor mechanical heat resistance.
• the j'th polyamine component in the epoxy resin composition has an active hydrogen equivalent weight of H j (g/eq) and that y j denotes the number of active hydrogen atoms contained in one molecule of the j'th polyamine component, the total amount of crosslinking points, C (moles), contained in the cured epoxy resin is calculated by expression (2) if all epoxy groups have reacted with all active hydrogen atoms in the polyamine.
• E i ⁇ x i and H j ⁇ y j represent the average molecular weight of i'th epoxy resin component and the average molecular weight of the j'th polyamine component, respectively. Further, (x i ⁇ 2) and (y j ⁇ 2) represent the number of crosslinking points produced from one molecule of the i'th epoxy resin component, and the number of crosslinking points produced from one molecule of the j'th polyamine component, respectively.
• the active hydrogen equivalent weight of polyamine products and the epoxy equivalent weight of epoxy resin products are available from their manufacturers. Even if the equivalent weight of a product is unknown, it can be calculated based on the structural formula if the product is pure material, or it can be determined from titration if the product is a mixture.
• the mixing ratio index, â is determined by expression (3) for the epoxy resin and the polyamine.
• the stoichiometric ratio, â, of the entire polyamine to the entire epoxy resin should preferably be in the range of 0.7-1.3. If the ratio is outside the range, the heat resistance and the elastic modulus of the cured product will be unfavorably low.
• an effective way is to use an epoxy resin that consists of a rigid backbone and a small number of, preferably two or more and less than three, functional groups.
• Preferred epoxy resins for this purpose include polyglycidyl ethers in the form of a condensation product of dicycolpentadiene and phenol or its substituent derivatives diglycidyl ether of dihydroxynaphthalene, diglycidyl ether of dihydroxybiphenyl or its substituent derivatives, diglycidyl ether of 9,9-bis(4-hydroxyphenyl)fluorine, and polyglycidyl ethers of phenol aralkyl resin.
• polyglycidyl ethers of phenol aralkyl resin are highly preferred because they have a large epoxy equivalent weight and can form a cured product with high heat resistance.
• Polyglycidyl ethers of phenol aralkyl resin are useful not only as a component of an epoxy resin composition that uses liquid aromatic polyamine as hardener, but also as a component of an epoxy resin composition for fiber reinforced composite material that uses polyamine as hardener.
• resin compositions for prepreg production consist of a polyglycidyl ether of phenol aralkyl resin, other epoxy resin components such as diglycidyl ether of bisphenol A and N,N,N′,N′-tetra-glycidyl-4,4′-diaminodiphenylmethane, a solid aromatic polyamine such as diaminodiphenylsulfone, and a thermoplastic resin, as an optional component, such as polyethersulfone; and liquid resin compositions for RTM, filament winding and hand lay-up that consist of a polyglycidyl ether of phenol aralkyl resin, other epoxy resin components such as diglycidyl ether of bisphenol A, and liquid aliphatic polyamine, such as isophoron diamine and 4,4′-methylenebis (2-methylcyclohexane amine), as hardener.
• resin compositions for prepreg production consist of a polyglycidyl ether of phenol a
• Epoxy resin compositions for fiber reinforced composite material to be used in the aerospace industry are required to be small in the decrease in glass transition temperature caused by water absorption, as well as able to form a cured product with a high glass transition temperature. Accordingly, the epoxy resin composition according to the invention should, after being cured for two hours at 180° C. and immersed in boiling water for 48 hours, preferably have a glass transition temperature of 130° C. or more.
• a more effective way may be to prevent the glass transition temperature from being decreased by water absorption.
• a way to prevent the glass transition temperature from being decreased by water absorption is to use, as said epoxy resin component with tri- or higher functionality, at least one epoxy resin selected from the group of N,N,N′,N′-tetra-glycidyl-4,4′-diaminodiphenylmethane and its alkyl-substituted derivatives, in combination with at least one epoxy resin selected from the group of N,N-diglycidyl aniline and its alkyl-substituted derivatives as said epoxy resin component with di- or higher and lower than tri-functionality.
• said epoxy resin selected from the group of N,N,N′,N′-tetraglycidyl-4,4′-diaminodiphenylmethane and its alkyl-substituted derivatives should preferably account for 30-90 wt % of the entire epoxy resin, while said epoxy resin selected from the group of N,N-diglycidyl aniline and its alkyl-substituted derivatives should preferably account for 10-30 wt % of the entire epoxy resin.
• the epoxy resin composition according to the invention should preferably be able to be precured at a relatively low temperature in the rage of 80° C.-140° C.
• Resin that consists of said preferred aromatic epoxy resin and said preferred aromatic polyamine can be subjected to precure of, for instance, about four hours at 130° C.
• Some accelerator is required, however, if precure is to be completed in a shorter period of time or at a lower temperature.
• an accelerator is also required to have a sufficiently long pot life at the inlet temperature without rapid suffering viscosity increase or rapid gelation.
• the epoxy resin composition according to the invention contains an accelerator
• said composition should, after being left to stand for one hour at 80° C., preferably have a viscosity not more than four times the initial viscosity, and the cured product produced by curing for two hours at 130° C. should preferably have a glass transition temperature of 120° C. or more.
• Acid type accelerators suitable for this purpose include strong acid esters, onium salts, Lewis acid•amine complexes, and polyphenols.
• Preferred strong acid esters include methyl p-toluenesulfonate and propyl p-toluenesulfonate.
• Preferred onium salts include p-acetoxyphenyl dimethylsufonium hexafluorophosphate, p-acetoxyphenyl benzylmethylsufonium hexafluorophosphate, and p-acetoxyphenyl dibenzylsufonium hexafluorophosphate.
• Preferred Lewis acid•amine complexes include BF 3 •piperidine complex.
• Preferred polyphenols include substituent derivatives of catechol such as 4-tert-butylcatechol and propyl gallate.
• the method for fiber reinforced composite material according to the present invention consists of impregnation of reinforcing fiber with said epoxy resin composition, followed by heating for curing.
• the method for fiber reinforced composite material according to the present invention should preferably be carried out by injecting said liquid epoxy resin composition into a reinforcing fiber substrate placed in a mold, followed by curing to provide fiber reinforced composite material, such a process being called resin transfer molding (RTM).
• Preferred reinforcing fibers include carbon fiber, glass fiber, aramid fiber, and metal fiber, which may be used solely or in combination. Carbon fiber is particularly preferred as material for aircraft and spacecraft. Said reinforcing fiber substrate may be fabric, braid, or mat of reinforcing fiber, or a preform produced by lamination and arrangement thereof followed by fixing their configuration with a tackifier or by stitching.
• Said mold may be a closed mold made of rigid material, or an open mold made of rigid material which is used in combination with flexible film (bag). In the latter case, reinforcing fiber is placed between said open mold made of rigid material and said flexible film.
• Preferred rigid materials for molds include metal (steel, aluminum, INVAR, etc.), FRP, wood, gypsum, and other known materials.
• Preferred materials for said flexible film include nylon, fluorocarbon resin, and silicone resin.
• the mold is usually closed under pressure and then an epoxy resin composition is injected under pressure.
• an outlet may be provided in addition to the inlet to allow suction to be performed by appropriate means such as vacuum pump.
• epoxy resin may be injected only under atmospheric pressure without using special pressurization means.
• an outlet is usually provided and suction is performed by such means as vacuum pump to allow injection to be achieved under atmospheric pressure, such a method being called VaRTM.
• VaRTM a method being called VaRTM.
• the inlet pressure may be adjusted to a value that is lower than atmospheric pressure.
• the use of a resin distribution medium as shown in U.S. Pat. No. 4,902,215 is effective to achieve good impregnation by injection under a pressure not higher than atmospheric pressure.
• a form core, honeycomb core, metal component, etc. may be placed in combination with reinforcing fiber in a mold to produce integrated composite material.
• a sandwich structure produced by placing reinforcing fiber on both sides of a form core or a honeycomb core, followed by molding, is useful because it is lightweight and has a high flexural rigidity.
• the surface of said rigid mold may be provided with a gel coat prior to placing reinforcing fiber in the mold.
• Epoxy resin composition may be in the from of a single liquid containing all components, which is injected from a single container; in the form of two liquids, A and B, which are stored in separate containers and injected after being combined in a mixer; or in the form of two liquids, A and B, which are fed into a container via a mixer and then injected from the container into a mold under atmospheric pressure.
• both the container and the mold used for production of the epoxy resin composition should preferably be maintained at appropriate constant temperatures during the resin injection process.
• the temperature of the container for epoxy resin composition or liquids A and B should preferably be in the range of 25° C. to 90° C., while the temperature of the mold in the injection process, that is, the inlet temperature, should preferably in the range of 40° C. to 90° C.
• Heat curing is carried out in the mold after completion of the resin injection.
• the temperature may be maintained for a certain period of time at the temperature of the mold at the time of injection; increased up to a point between the temperature of the mold at the time of injection and the highest curing temperature and, after being maintained there for a certain period of time, increased again up to the highest curing temperature, followed by being maintained there for a certain period of time to ensure curing; or increased up to the highest curing temperature and maintained there for a certain period of time to ensure curing.
• the time period for which the highest curing temperature is maintained for curing in the mold should preferably be in the range of 0.5 to 12 hours, more preferably 1 to 4 hours.
• the material After being removed out of the mold, the material may be aftercured at temperature higher than the highest curing temperature in the mold. In this case, the curing in the mold serves as precure. Aftercure should preferably be performed for 0.5 to 12 hours, more preferably for 1 to 4 hours.
• final curing may be carried out at a temperature of 170° C. to 190° C.
• the highest curing temperature is 170° C. to 190° C. in a process without an aftercure step, while if an aftercure step is included, it is performed at an aftercure temperature of 170° C. to 190° C.
• the precure temperature that is, the maximum temperature in the precure step, should preferably be in the range of 80° C. to 140° C.
• Production of the fiber reinforced composite material according to the invention may be carried out not only by the RTM method but also by any method that is designed for producing fiber reinforced composite material from a liquid epoxy resin composition, such as filament winding, pultrusion, and hand lay-up.
• the fiber reinforced composite material according to the invention comprises said reinforcing fiber in combination with a cured product of said epoxy resin according to the present invention used as a matrix.
• said reinforcing fiber should preferably account for 50-85% by volume in order to achieve a high specific strength and low rigidity.
• Fiber reinforced composite materials produced according to the present invention are not limited to particular applications, and can serve as material for parts of aircraft, including main wing, tail, rotor blade, fairing, cowl, and door; parts of spacecraft, including motor case and main wing; and parts of space satellite body structure. They can also be used preferably as material for automobile chassis and railroad vehicle body structure.
• An epoxy resin composition was injected into the mold, heated in a hot air dryer from 30° C. at a heating rate of 1.5° C./min, maintained at 130° C. for two hours or at 180° C. for two hours to ensure heat curing, and then cooled down to 30° C. at a rate of 2.5° C./min to provide a cured resin plate of 2 mm in thickness.
• expansion type viscoelasticity measuring equipment ARES, supplied by Rheometric Scientific Inc. was used under the conditions of a heating rate of 5° C./min and a frequency of 1 Hz.
• an epoxy resin composition was cured by heating at 180° C. for two hours to produce a cured resin plate of 6 mm in thickness.
• Specimens of 6 mm in width and 10 mm in length were cut out of the cured resin plate produced above, and heated from 30° C. to 180° C. at a rate of 3° C./min in a TMA 2940 thermomechanical analyzer supplied by TA Instruments to determine their coefficient of linear expansion in the temperature range from 30° C. to 160° C.
• an epoxy resin composition was cured by heating at 180° C. for two hours to produce a cured resin plate of 2 mm in thickness.
• Specimens of 10 mm in width and 60 mm in length were cut out of the cured resin plate produced above, and a three-point bending test was carried out under the conditions of a testing speed 2.5 mm and a support span length of 32 mm to determine their flexural modulus according to JIS K7203.
• the mold was heated up to 80° C., and an epoxy resin composition heated separately elsewhere at 80° C. was injected with a resin injector into the mold under an inlet pressure of 0.2 MPa.
• the mold was heated up to 130° C. at a rate of 1.5° C./min, and heat curing was performed for two hours at 130° C., followed by cooing down to 30° C. and release of the product.
• the temperature was raised from 30° C. to 180° C. at a rate of 1.5° C./min, followed by curing for two hours at 180° C. and cooling down to 30° C. to provide fiber reinforced composite material.
• a piece of 229 mm in length and 12.7 mm in width was cut out of the fiber reinforced composite material with its length direction aligned in the 0° direction to produce a specimen for 0° tensile strength testing, and the 0° tensile strength of the fiber reinforced composite material was determined according to ASTM-D3039 using a universal materials testing machine (Model 4208 supplied by Instron Japan Co., Ltd.). The cross head speed during measurement was 1.27 mm/min and the measuring temperature was 23° C.
• a piece of 79.4 mm in length and 12.7 mm in width was cut out of fiber reinforced composite material produced by the same procedure as in (6) to produce a specimen for 0° compressive strength testing, and the 0° compressive strength of the fiber reinforced composite material was determined according to ASTM D695 using a universal materials testing machine (Model 4208 supplied by Instron Japan Co., Ltd.). The cross head speed during measurement was 1.27 mm/min and the measuring temperature was 23° C.
• a specimen for 0° compressive strength testing produced by the same procedure as in (8) was immersed in warm water of 72° C. for 14 days, and its 0° compressive strength was measured at 82° C.
• Pieces of 395 mm ⁇ 395 mm were cut out of unidirectional carbon fiber fabric (plain weave; warp: T800S-24K-10C carbon fiber supplied by Toray Industries Inc., fiber areal weight 295 g/m2, warp density 7.2/25 mm; weft: ECE225 1/0 1Z glass fiber supplied by Nitto Boseki Co., Ltd., weft density 7.5/25 mm), 12 of which were then placed one on top of another, in a metal mold having a plate-shape cavity of 400 mm ⁇ 400 mm ⁇ 1.2 mm, in the direction of 45°, 0°, ⁇ 45° and 90° respectively (repeated three times) relative to the direction of carbon fiber, which was defined as the 0° direction, followed by another 12 pieces being placed one on top of another in the direction of 90°, ⁇ 45°, 0° and 45° respectively (repeated three times), and the mold was clamped.
• unidirectional carbon fiber fabric plain weave; warp: T800S-24
• the mold was heated to 70° C., and an epoxy resin composition heated separately elsewhere at 70° C. was injected with a resin injector into the mold under an inlet pressure of 0.2 MPa to achieve impregnation of the reinforcing fiber substrate.
• the mold was heated up to 130° C. at a rate of 1.5° C./min, and maintained for two hours at 130° C., followed by cooing down to 30° C and release of the product.
• the temperature was raised from 30° C. to 180° C. at a rate of 1.5° C./min, followed by curing for two hours at 180° C. and cooling down to 30° C. to provide fiber reinforced composite material.
• a piece of 101.6 mm in width and 152.4 mm in length was cut out of the fiber reinforced composite material produced above, to produce a specimen with its length direction aligned in the 0° direction, and CAI was determined according to the Boeing testing method BMS7260.
• the equipment used was a Model 1128 tensilon supplied by Instron Corporation.
• the drop impact was 6.7 J/mm
• the cross head speed during measurement 1.27 mm/min
• Component (1) Epoxy Resin that is Liquid at Room Temperature
• Epikote 630 (N,N,O-triglycidyl-p-aminophenol, supplied by Japan Epoxy Resins Co., Ltd., epoxy equivalent weight 97.5).
• Epikote 807 diglycidyl ether of bisphenol F, supplied by Japan Epoxy Resins Co., Ltd., epoxy equivalent weight 170.
• AER 4152 epoxy resin having a oxazolidone ring produced by reacting two molecules of diglycidyl ether of bisphenol A and one molecule of tolylene diisocyanate, supplied by Asahi Kasei Epoxy Co., Ltd., epoxy equivalent weight 340
• Component (2) Aromatic Polyamine that is Liquid at Room Temperature
• PTSP propyl-p-toluenesulfonate, supplied by Wako Pure Chemical Industries, Ltd.
• TBC (4-tert-butylcatechol, supplied by Ube Industries Co., Ltd.)
• Liquid (A1) One hundred (100) parts of “Epikote” 630, selected as component (1), is used as Liquid (A1). Seventy (70) parts of “Epicure” W, selected as component (2), and 30 parts of 3,3′-DAS, selected as component (3), are mixed and stirred for one hour at 100° C. until 3,3′-DAS is dissolved homogeneously to provide liquid (B1). No precipitation took place in Liquid (B1) when stored at 5° C. for 30 days.
• this epoxy resin composition was used to produce fiber reinforced composite material, followed by measurement of its 0° tensile strength, which was found to be 2650 MPa, showing that its strength was sufficiently high.
• Liquid (A1) was prepared by the same procedure as in example 2. Seventy (70) parts of “Epicure” W, selected as component (2), 15 parts of 3,3′-DAS, selected as component (3), and 15 parts of “Sumicure” S were mixed and stirred for one hour at 100° C. until 3,3′-DAS and “Sumicure” S were dissolved homogeneously to provide liquid (B1). No precipitation took place in Liquid (B1) when stored at 5° C. for 30 days.
• Liquid (A1) was prepared by the same procedure as in example 1. Further, 2 parts of PTSP, used as accelerator, was added to liquid (B1) prepared in example 2 to provide a new liquid (B1)
• Liquid (A1) and liquid (B1) were prepared by the same procedure as in example 3 except that two parts of TBC was added as accelerator instead of PTSP which was used in example 3.
• Liquid (A1) was prepared by the same procedure as in example 1. Seventy (60) parts of “Epicure” W, selected as component (2), and 40 parts of 3,3′-DAS, selected as component (3), were mixed and stirred for one hour at 100° C. until 3,3′-DAS is dissolved homogeneously to provide liquid (B1). No precipitation took place in Liquid (B1) when stored at 5° C. for 30 days.
• this epoxy resin composition was used to produce fiber reinforced composite material, followed by measurement of its 0° tensile strength, which was found to be 2840 MPa, showing that its strength was sufficiently high.
• this epoxy resin composition was used to produce fiber reinforced composite material, followed by measurement of its 0° tensile strength, which was found to be 2860 MPa, showing that its strength was sufficiently high.
• this epoxy resin composition was used to produce fiber reinforced composite material, followed by measurement of its 0° tensile strength, which was found to be 2380 MPa, showing that its strength was lower than in example 1.
• Liquid (A1) was prepared by the same procedure as in example 1. Then, 77 parts of “Epicure” W, selected as component (2), and 23 parts of “Sumicure” S, selected as component (3), were mixed and stirred for one hour at 100° C. to achieve homogeneous dissolution, and after cooling down to 70° C., 17 parts of BF 3 •piperidine complex was added, followed by further stirring for 30 minutes at 70° C. for homogeneous dissolution to provide liquid (B1). Said liquid (B1) contained a smaller amount of component (2) than required for the present invention, and accordingly precipitation of crystals was seen when the liquid was stored for 30 days at 5° C.
• this epoxy resin composition was used to produce fiber reinforced composite material, but the resulting fiber reinforced composite material was so high in the viscosity at 80° C. that it contained unpregnated portions.
• Liquid (A1) was prepared by the same procedure as in example 1. The, 91 parts of Epicure W, selected as component (2), 4.5 parts of 3,3′-DAS, 4.5 parts of “Sumicure” S, both selected as component (3), and 3 parts of Cuazorl 2E4MZ, selected as accelerator, were mixed and stirred for one hour at 100° C. for homogeneous dissolution of 3,3′-DAS and “Sumicure” S to provide liquid (B1). No precipitation took place in liquid (B1) when stored at 5° C. for 30 days.
• Epikote 630 (N,N,O-triglycidyl-p-aminophenol, supplied by Japan Epoxy Resins Co., Ltd., epoxy equivalent weight 97.5).
• Epikote 825 diglycidyl ether of bisphenol A, supplied by Japan Epoxy Resins Co., Ltd., epoxy equivalent weight 175).
• AK-601 diglycidyl hexahydrophthalate, supplied by Nippon Kayaku Ltd., epoxy equivalent weight 154)
• PTSP n-propyl ester of p-toluenesulfonic acid, supplied by Wako Pure Chemical Industries, Ltd.
• TBC tert-butyl catechol, supplied by Ube Industries Ltd.
• this epoxy resin composition was used to produce fiber reinforced composite material, followed by measurement of its 0° tensile strength, which was found to be 2730 MPa, showing that its strength was sufficiently high.
• this epoxy resin composition was used to produce fiber reinforced composite material, followed by measurement of its 0° tensile strength, which was found to be 2670 MPa, showing that its strength was sufficiently high.
• Liquid (B2) used in example 8 was used as component (6).
• this epoxy resin composition was used to produce fiber reinforced composite material, followed by measurement of its 0° tensile strength, which was found to be 2670 MPa, showing that its strength was sufficiently high.
• this epoxy resin composition was used to produce fiber reinforced composite material, followed by measurement of its 0° tensile strength, which was found to be 2760 MPa, showing that its strength was sufficiently high.
• this epoxy resin composition was used, to produce fiber reinforced composite material, followed by measurement of its 0° tensile strength, which was found to be 2740 MPa, showing that its strength was sufficiently high.
• this epoxy resin composition was used to produce fiber reinforced composite material, followed by measurement of its 0° tensile strength, which was found to be 2370 MPa, showing that its strength was lower than required for good reinforced composite material.
• NC-3000 phenol-aralkyl type epoxy resin, supplied by Nippon Kayaku Co., Ltd., epoxy equivalent weight 275
• Epikote 825 diglycidyl ether of bisphenol A, liquid, at room temperature, supplied by Japan Epoxy Resins Co., Ltd., epoxy equivalent weight 175).
• AK-601 diglycidyl hexahydrophthalate, supplied by Nippon Kayaku Co., Ltd., epoxy equivalent weight 154)
• Epikote 834 bisphenol A type epoxy resin, solid at room temperature, supplied by Japan Epoxy Resins Co., Ltd., epoxy equivalent weight 250
• TBC (4-tert-butylcatechol, supplied by Ube Industries Ltd.)
• this epoxy resin composition was used to produce fiber reinforced composite material, followed by measurement of its 0° tensile strength, 0 compressive strength, and CAI, which were found to be 2870 MPa, 1390 MPa and 234 MPa, respectively, showing that it had sufficiently good mechanical properties.
• this epoxy resin composition was used to produce fiber reinforced composite material, followed by measurement of its 0° tensile strength, 0° compressive strength, and CAI, which were found to be 2860 MPa, 1420 MPa and 241 MPa, respectively, showing that it had sufficiently good mechanical properties.
• this epoxy resin composition was used to produce fiber reinforced composite material, followed by measurement of its 0° tensile strength, 0° compressive strength, and CAI, which were found to be 2500 MPa, 1380 MPa and 200 MPa, respectively, showing that though it had high 0° tensile strength, it was poor in 0° compressive strength and CAI.
• Epoxy resin used here was the same as in example 13 except that NC-3000 used in example 13 was replaced with “Epikote” 834 in about the same amount in terms of epoxy equivalent weight. The same hardener as in example 13 was used here.
• this epoxy resin composition was used to produce fiber reinforced composite material, followed by measurement of its 0° tensile strength, 0° compressive strength, and CAI, which were found to be 2870 MPa, 1410 MPa and 236 MPa, respectively, showing that it had sufficiently good mechanical properties.
• Epikote 825 diglycidyl ether of bisphenol A, liquid at room temperature, supplied by Japan Epoxy Resins Co., Ltd., epoxy equivalent weight 175)
• GAN N,N-diglycidyl aniline, supplied by Nippon Kayaku Ltd., epoxy equivalent weight 154)
• Epikote 1750 diglycidyl ether of bisphenol F, liquid at room temperature, supplied by Japan Epoxy Resins Co., Ltd., epoxy equivalent weight 160.
• TBC (4-tert-butylcatechol, supplied by Ube Industries Ltd.)
• this epoxy resin composition was used to produce fiber reinforced composite material, followed by measurement of its 0° tensile strength, 0° compressive strength, H/W 0° compressive strength, and CAI, which were found to be 2730 MPa, 1420 MPa, 1247 MPa, and 220 MPa, respectively, showing that it had sufficiently good mechanical properties.
• this epoxy resin composition was used to produce fiber reinforced composite material, followed by measurement of its 0° tensile strength, 0° compressive strength, H/W 0° compressive strength, and CAI, which were found to be 2730 MPa, 1470 MPa, 1260 MPa, and 221 MPa, respectively, showing that it had sufficiently good mechanical properties.
• cured resin plates produced by the method described above were examined to determine their glass transition temperature after immersion in boiling water for 48 hours and their flexural modulus at 82° C., which were 130° C. and 2.2 GPa, respectively, showing that they had sufficiently high heat resistance and elastic modulus.
• this epoxy resin composition was used to produce fiber reinforced composite material, followed by measurement of its 0° tensile strength, 0° compressive strength, H/W 0° compressive strength, and CAI, which were found to be 2730 MPa, 1410 MPa, 1140 MPa, and 234 MPa, respectively, showing that it had sufficiently good mechanical properties.
• this epoxy resin composition was used to produce fiber reinforced composite material, followed by measurement of its 0° tensile strength, 0° compressive strength, H/W 0° compressive strength, and CAI, which were found to be 2830 MPa, 1420 MPa, 1190 MPa, and 227 MPa, respectively, showing that it had sufficiently good mechanical properties.
• this epoxy resin composition was used to produce fiber reinforced composite material, followed by measurement of its 0° tensile strength, 0° compressive strength, H/W 0° compressive strength, and CAI, which were found to be 2470 MPa, 1300 MPa, 980 MPa, and 236 MPa, respectively, showing that though it had high 0° compressive strength, it was poor in H/W 0 compressive strength.
• this epoxy resin composition was used to produce fiber reinforced composite material, followed by measurement of its 0° tensile strength, 0° compressive strength, H/W 0° compressive strength, and CAI, which were found to be 2430 MPa, 1480 MPa, 1260 MPa, and 193 MPa, respectively, showing that though it had high compressive strength and high H/W 0° compressive strength, it was poor in tensile strength and CAI.
• Component (9) At Least One Epoxy Resin Selected from the Group of N,N,N′,N′-tetraglycidyl-4,4′-diaminodiphenylmethane and its Alkyl-Substituted Derivatives
• Component (10) At Least One Epoxy Resin Selected from the Group of N,N-diglycidyl Aniline and its Alkyl-Substituted Derivatives
• GAN diglycidyl aniline, supplied by Nippon Kayaku Ltd., epoxy equivalent weight 154)
• NC-3000 polyglycidyl ether of phenol aralkyl resin, supplied by Nippon Kayaku Ltd., epoxy equivalent weight 275
• TBC (4-tert-butylcatechol, supplied by Ube Industries Ltd.)
• this epoxy resin composition was used to produce fiber reinforced composite material, followed by measurement of its 0° tensile strength, 0° compressive strength, H/W 0° compressive strength, and CAI, which were found to be 2630 MPa, 1370 MPa, 1140 MPa, and 222 MPa, respectively, showing that it had sufficiently good mechanical properties.
• this epoxy resin composition was used to produce fiber reinforced composite material, followed by measurement of its 0° tensile strength, 0° compressive strength, H/W 0° compressive strength, and CAI, which were found to be 2760 MPa, 1450 MPa, 1190 MPa, and 200 MPa, respectively, showing that it had sufficiently good mechanical properties.
• this epoxy resin composition was used to produce fiber reinforced composite material, followed by measurement of its 0° tensile strength, 0° compressive strength, H/W 0° compressive strength, and CAI, which were found to be 2700 MPa, 1410 MPa, 1200 MPa, 220 MPa, respectively, showing that it had sufficiently good mechanical properties.
• this epoxy resin composition was used to produce fiber reinforced composite material, followed by measurement of its 0° tensile strength, 0° compressive strength, H/W 0° compressive strength, and CAI, which were found to be 2920 MPa, 1480 MPa, 1190 MPa, and 234 MPa, respectively, showing that it had sufficiently good mechanical properties.
• this epoxy resin composition was used to produce fiber reinforced composite material, followed by measurement of its 0° tensile strength, 0° compressive strength, H/W 0° compressive strength, and CAI, which were found to be 2780 MPa, 1470 MPa, 1070 MPa, and 193 MPa, respectively, showing that it had sufficiently good mechanical properties.
• this epoxy resin composition was used to produce fiber reinforced composite material, but the resulting fiber reinforced composite material was so high in the viscosity at 80° C. that it contained many unpregnated portions.
• this epoxy resin composition was used to produce fiber reinforced composite material, but the resulting fiber reinforced composite material was so high in the viscosity at 80° C. that it contained many unpregnated portions.
• this epoxy resin composition was used to produce fiber reinforced composite material, followed by measurement of its 0° tensile strength, 0° compressive strength, H/W 0° compressive strength, and CAI, which were found to be 2890 MPa, 1300 MPa, 940 MPa, and 240 MPa, respectively, showing that though it was high in 0° tensile strength, 0° compressive strength, and CAI, but it was poor in H/W 0° compressive strength.

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• 2002
  • 2002-11-06 WO PCT/JP2002/011556 patent/WO2003040206A1/ja active IP Right Grant
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