US 7,491,774 B2
Producing granular epoxy resin by refining and pulverizing solid epoxy resin
Yasuyuki Murata, Yokkaichi (Japan); Atsuhito Hayakawa, Yokkaichi (Japan); and Akihiro Itou, Yokkaichi (Japan)
Assigned to Japan Epoxy Resins Co., Ltd., Tokyo (Japan)
Filed on Feb. 12, 2007, as Appl. No. 11/704,938.
Application 11/704938 is a division of application No. 10/792859, filed on Mar. 05, 2004, granted, now 7,285,602.
Claims priority of application No. 2003-104493 (JP), filed on Apr. 08, 2003.
Prior Publication US 2007/0135616 A1, Jun. 14, 2007
Int. Cl. B32B 3/04 (2006.01); B32B 3/10 (2006.01); C08L 63/02 (2006.01); C08L 63/04 (2006.01)
U.S. Cl. 525—481  [428/130; 428/137; 428/138; 525/480; 525/523; 525/524; 525/525] 2 Claims
 
1. A production method of granular epoxy resin comprising:
an epoxy resin preparing step of preparing an epoxy resin which is solid at ordinary temperature by reaction between a phenol compound and epihalohydrin;
a purifying processing step of refining the prepared epoxy resin which is solid at ordinary temperature so that the total content of compounds having a molecular weight of 200 or less is 0.28% by mass or less of the entire epoxy resin; and
a pulverizing step of pulverizing the refined epoxy resin obtained by the purifying processing step under conditions so as not to make the total content of compounds having a molecular weight of 200 or less exceeding 0.3% by mass,
wherein the epoxy resin which is solid at ordinary temperature prepared by said epoxy resin preparing step is mainly composed of at least one selected from oligomers represented by the following general formula (1) and oligomers represented by the following general formula (2), and
at least 50% by mass of the entire epoxy resin consists of at least one oligomer of n1=0 in the following general formula (1) and having a molecular weight of 500 or less and/or at least one oligomer of n2=0 in the following general formula (2) and having a molecular weight of 500 or less;

OG Complex Work Unit Drawing
wherein in the above formula (1), G is a glycidyl group;
R1 is a hydrocarbon group having from 1 to 10 carbon atoms and each R1 can be the same or different;
X is a divalent hydrocarbon group having from 1 to 18 carbon atoms, —O—, —S—, or a group represented by the following general formula (3) and each X can be the same or different;

OG Complex Work Unit Drawing
wherein the above formula (3), G is a glycidyl group, R3 is a hydrogen atom or a hydrocarbon group having from 1 to 5 carbon atoms;
p1 is an integer between 0 and 4 and each p1 can be the same or different;
n1 is an integer between 0 and 10;

OG Complex Work Unit Drawing
wherein the above formula (2), R2 is a hydrocarbon group having from 1 to 10 carbon atoms and each R2 can be the same or different;
Y is a divalent hydrocarbon group having from 1 to 18 carbon atoms, —O—, —S—, —CO—, —SO2—, or a direct bond and each Y can be the same or different;
p2 is an integer between 0 and 4 and each p2 can be the same or different;
n2 is an integer between 0 and 10.