Compositions useful for preparing composites and composites produced therewith
View Patent ↗A composite prepared using a thermosettable epoxy resin composition having, as components: (1) an epoxy resin; (2) an epoxidized cycloaliphatic dicyclopentadiene phenolic resin; (3) an optional epoxidized bisphenol-A novolac resin; (4) an optional oligomeric butadiene; (5) an optional organic solvent; and (6) an alkylphenol novolac resin, the alkylphenol novolac resin serving as a curing agent. The composite so prepared may have good physical properties and superior a electrical properties as compared to conventional composites, such as laminates. The prepregs used to make the laminates may have a better surface appearance as well.
1. An epoxy resin composition comprising:
an epoxy resin component;
an epoxidized cycloaliphatic dicyclopentadiene phenolic resin;
an alkylphenol novolac resin; and
an oligomeric butadiene homopolymer of butadiene having a weight average molecular weight (Mw) from about 1,000 Daltons to about 20,000 Daltons.
2. The epoxy resin composition of claim 1 further comprising an epoxidized bisphenol-A novolac resin.
3. The epoxy resin composition of claim 1 wherein the epoxy resin component is present, as a weight percentage of the composition, from about 30 wt % to about 80 wt %.
4. The epoxy resin composition of claim 1 wherein epoxidized cycloaliphatic dicyclopentadiene phenolic resin utilized in the composition is produced from an epihalohydrin and a dicyclopentadiene polyphenolic compound having the general formula:
wherein “n” represents a whole number from 0 to 7; Ph is a phenylol radical derived from mononuclear phenol, and D is a tricyclodecylene radical having a general formula:
5. The epoxy resin composition of claim 1 wherein the epoxidized cycloaliphatic dicyclopentadiene phenolic resin is present, as a weight percentage of the composition, from about 5 wt % to about 70 wt %.
6. The epoxy resin composition of claim 2 wherein the epoxidized bisphenol-A novolac resin component is present, as a weight percentage of the composition, from about 10 wt % to about 40 wt %.
7. The epoxy resin composition of claim 1 wherein the oligomeric butadiene component is present, as a weight percentage of the composition, from about 0.05 wt % to about 4 wt %.
8. The epoxy resin composition of claim 1 further comprising a solvent component, and the solvent component is present, as a weight percentage of the composition, from about 15 wt % to about 50 wt %.
9. The epoxy resin composition of claim 1 wherein the alkylphenol novolac resin serving as the curing agent has the general formula:
where:
Ar represents an aryl or alkyl-aryl group;
each Ar group contains x number of non-aromatic carbon atoms,
OH represents a hydroxyl group bonded to each Ar group,
each R 1 represents substituent group(s) bonded to each Ar group,
each R 2 represents a group connecting adjacent Ar groups,
n is a number between 2 and 20,
x is an integer from 4 to 8,
y is an integer from 1 to x−2, and
z is an integer from 1 to x−3.
10. The epoxy resin composition of claim 1 wherein the alkylphenol novolac resin serving as the curing agent has the general formula:
wherein:
R 1 represents a single alkyl substituent in the para position having from 4 to 9 carbon atoms and is sometimes a butyl or octyl group and R 2 is a methyl group.
11. The epoxy resin composition of claim 1 wherein a ratio of the total epoxy groups to the phenolic hydroxyl equivalents is between about 0.5 to about 1.5.
12. The epoxy resin composition of claim 1 wherein the oligomeric butadiene homopolymer comprises a 1,2 vinyl group content from about 25 to about 99 percent.
13. The epoxy resin composition of claim 1 wherein the composition, when cured, has a T g of about 150° C. or greater and a T d of 300° C. or greater.
14. A process for forming a composition, comprising:
providing an epoxy resin and an epoxidized cycloaliphatic dicyclopentadiene phenolic resin to a reactor to form a mixture; and
providing an oligomeric butadiene homopolymer and an alkylphenol novolac resin to the mixture.
15. The process of claim 14 , wherein:
the epoxy resin is present, as a weight percentage, from about 30 wt % to about 80 wt %;
the epoxidized cycloaliphatic dicyclopentadiene phenolic resin is present, as a weight percentage of the composition, from about 5 wt % to about 70 wt %;
the epoxidized bisphenol-A novolac resin component is present, as a weight percentage of the composition, from about 10 wt % to about 40 wt %; and
the oligomeric butadiene component is present, as a weight percentage of the composition, from about 0.05 wt % to about 4 wt %; and wherein the total amount of components is 100 wt. %.
16. The process of claim 14 , wherein the process further comprises adding a solvent component with the providing the epoxy resin and the epoxidized cycloaliphatic dicyclopentadiene phenolic resin, adding a solvent component with the providing the oligomeric butadiene homopolymer and the alkylphenol novolac resin, or both.
17. The process of claim 16 , wherein the solvent component is present, as a weight percentage of the composition, from about 15 wt % to about 50 wt %.
18. The process of claim 14 , further comprising impregnating a substrate with the composition.