US 12,247,121 B2
Curable epoxy composition and its use in prepregs and core filling
Hubert Simon, Buhl (FR); Markus Rudin, Frenkendorf (CH); and Nicolas Mullot, Uffheim (FR)
Assigned to Von Roll Schweiz AG, (DE)
Appl. No. 17/437,479
Filed by Von Roll Schweiz AG, Breitenbach (CH)
PCT Filed Mar. 10, 2020, PCT No. PCT/EP2020/056285
§ 371(c)(1), (2) Date Sep. 9, 2021,
PCT Pub. No. WO2020/182781, PCT Pub. Date Sep. 17, 2020.
Claims priority of application No. 19161799 (EP), filed on Mar. 11, 2019.
Prior Publication US 2022/0153988 A1, May 19, 2022
Int. Cl. C08G 59/32 (2006.01); C08G 59/14 (2006.01); C08G 59/40 (2006.01); C08J 5/24 (2006.01); C08K 3/22 (2006.01); C08K 3/36 (2006.01); C08K 3/38 (2006.01); C08K 5/19 (2006.01); C08K 5/521 (2006.01); C08K 5/5373 (2006.01); C08L 63/04 (2006.01)
CPC C08L 63/04 (2013.01) [C08G 59/14 (2013.01); C08G 59/3218 (2013.01); C08G 59/4021 (2013.01); C08J 5/244 (2021.05); C08J 5/249 (2021.05); C08K 3/22 (2013.01); C08K 3/36 (2013.01); C08K 3/38 (2013.01); C08K 5/19 (2013.01); C08K 5/521 (2013.01); C08K 5/5373 (2013.01); C08J 2363/04 (2013.01); C08K 2003/2217 (2013.01); C08K 2003/2227 (2013.01); C08K 2201/019 (2013.01); C08L 2201/02 (2013.01)] 16 Claims
 
1. A curable composition comprising:
i) a glycidyl ether of a novolac, comprising moieties having the formula (I):

OG Complex Work Unit Chemistry
wherein
Ra is either always hydrogen or always methyl;
B is either always *—CH2—** or always

OG Complex Work Unit Chemistry
a fraction of 0.8 to 0.99 of the Y moieties are essentially —O-glycidyl, this fraction being designated as x, and the remainder of the Y moieties, this fraction being designated as (1-x), are divalent bridging spacers of the structure *—O—CH2—CH(OH)—CH2—O—** connecting two moieties according to above formula (I); and
n is a number in the range of 0.1 to 3.0;
and wherein said novolac glycidyl ether has an epoxy equivalent weight EEW in the range of 160 to 270 g/eq. and the average number of epoxy groups per molecule of novolac glycidyl ether (I), designated as f, is in the range of 2.1 to 5.0;
ii) dicyandiamide;
iii) an urea derivative of the formula (II):

OG Complex Work Unit Chemistry
wherein
R1a and R1b may be equal or different and are individually selected from the group of hydrogen, C1-C6-alkyl and C3-C6-cycloalkyl; or R1a and R1b taken together with the nitrogen atom to which they are attached form a heterocyclic substituent selected from the group consisting of aziridinyl, azetidinyl, pyrrolidinyl and piperidinyl;
R2a and R2b are equal or different and are individually selected from the groups consisting of hydrogen and C1-C6-alkyl;
R3a, R3b, and R4 are equal or different and are individually selected from the group consisting of hydrogen, halogen, C1-C6-alkyl, C1-C6-alkoxy, —C(O)R5, —N(H)—C(O)—NR1aR1b, —CN, NO2, trifluoromethyl, —SOR6 and SO2R6; wherein R5 is selected from the group consisting of hydrogen, C1-C6-alkyl, C1-C6-alkoxy, C3-C6-cycloalkyl and NR1aR1b, and R6 is selected from the group consisting of C1-C6-alkyl, C1-C6-alkoxy, and C3-C6-cycloalkyl;
(iv) a powdered SiO2-based frit comprising 50-70% by weight of SiO2, Na2O and K2O, in combined amounts of 10 to 30% by weight; and Al2O3, B2O3, CaO, ZnO and fluorine in amounts of 0 to 5% by weight, 0 to 40% by weight, 0 to 10% by weight, 0 to 10% by weight, and 0 to 5% by weight, respectively; wherein all amounts are based on the frit, with the proviso that the amounts of the indicated components add to at least 95% by weight, of the frit; and the amount of the powdered SiO2-based frit is 10 to 30% by weight, based on the composition;
and
v) optionally, a reactive diluent being selected from the group consisting of glycidyl ethers of monohydric phenols, glycidyl ethers of cresols and glycidyl ethers of aliphatic or cycloaliphatic C4-8-alcohols.