| 主权项 |
1. A method for preparing a fiber-reinforced part based on cyanate ester or a cyanate ester/epoxy blend, comprising the steps of
(i) providing a liquid mixture comprising
(a) from 15 to 99.9 wt. % of at least one di- or polyfunctional cyanate ester selected from the group consisting of difunctional cyanate esters of formula wherein R1 through R4 are independently selected from the group consisting of hydrogen, linear C1-10 alkyl, halogenated linear C1-10 alkyl, branched C4-10 alkyl, halogenated branched C4-10 alkyl, C3-8 cycloalkyl, halogenated C3-8 cycloalkyl, C1-10 alkoxy, halogen, phenyl and phenoxy, difunctional cyanate esters of formula wherein R5 through R12 are independently selected from the group consisting of hydrogen, linear C1-10 alkyl, halogenated linear C1-10 alkyl, branched C4-10 alkyl, halogenated branched C4-10 alkyl, C3-8 cycloalkyl, halogenated C3-8 cycloalkyl, C1-10 alkoxy, halogen, phenyl and phenoxy;and Z1 indicates a direct bond or a divalent moiety selected from the group consisting of —O—, —S—, —S(═O)—, —S(═O)2—, —CH(CF3)—, —C(CF3)2—, —C(═O)—, —C(═CH2)—, —C(═CCl2)—, —Si(CH3)2—, linear C1-10 alkanediyl, branched C4-10 alkanediyl, C3-8 cycloalkanediyl, 1,2-phenylene, 1,3-phenylene, 1,4-phenylene, —N(R13)— wherein R13 is selected from the group consisting of hydrogen, linear C1-10 alkyl, halogenated linear C1-10 alkyl, branched C4-10 alkyl, halogenated branched C4-10 alkyl, C3-8 cycloalkyl, phenyl and phenoxy, and moieties of formulas wherein X is hydrogen or fluorine;and polyfunctional cyanate esters of formula and oligomeric mixtures thereof, wherein n is an integer from 1 to 20 and R14 and R15 are independently selected from the group consisting of hydrogen, linear C1-10 alkyl and branched C4-10 alkyl:(b) from 0 to 84.9 wt. % of at least one di- or polyfunctional epoxy resin selected from the group consisting of epoxy resins of formula wherein Q1 and Q2 are independently oxygen or —N(G)- with G=oxiranylmethyl, and R16 through R19 are independently selected from the group consisting of hydrogen, linear C1-10 alkyl, halogenated linear C1-10 alkyl, branched C4-10 alkyl, halogenated branched C4-10 alkyl, C3-8 cycloalkyl, halogenated C3-8 cycloalkyl, C1-10 alkoxy, halogen, phenyl and phenoxy;epoxy resins of formula wherein Q3 and Q4 are independently oxygen or —N(G)- with G=oxiranylmethyl, R20 through R27 are independently selected from the group consisting of hydrogen, linear C1-10 alkyl, halogenated linear C1-10 alkyl, branched C4-10 alkyl, halogenated branched C.4-10 alkyl, C3-8 cycloalkyl, halogenated C3-8 cycloalkyl, C1-10 alkoxy, halogen, phenyl and phenoxy, and Z2 indicates a direct bond or a divalent moiety selected from the group consisting of —O—, —S—, —S(═O)—, —S(═O)2—, —CH(CF3)—, —C(CF3)2—, —C(═O)—, —C(═CH2)—, —C(CCl2)—, —Si(CH3)2—, linear C1-10 alkanediyl, branched C4-10 alkanediyl, C3-8 cycloalkanediyl, 1,2-phenylene, 1,3-phenylene, 1,4-phenylene, glycidyloxyphenylmethylene, and —N(R28)- wherein R28 is selected from the group consisting of hydrogen, linear C1-10 alkyl, halogenated linear C1-10 alkyl, branched C4-10 alkyl, halogenated branched C4-10 alkyl, C3-8 cycloalkyl, phenyl and phenoxy;epoxy resins of formula and oligomeric mixtures thereof, wherein m is an integer from 1 to 20, Q5 is oxygen or —N(G)- with G=oxiranylmethyl, and R29 and R30 are independently selected from the group consisting of hydrogen, linear C1-10 alkyl and branched C4-10 alkyl; and naphthalenediol diglycidyl ethers; and(c) from 0.1 to 25 wt % of a metal-free catalyst;wherein the percentages of (a), (b) and (c) are based on the total amount of (a), (b) and (c); (ii) providing a fiber structure (iii) placing said fiber structure in a mold or on a substrate, (iv) impregnating said fiber structure with said liquid mixture, optionally by applying elevated pressure and/or evacuating the air from the mold and fiber structure, at a temperature of 20 to 80° C., and (v) curing said liquid mixture by applying a temperature of 30 to 300° C., preferably 30 to 220° C., for a time sufficient to cure said mixture. |
