SMA resin formulation
Resin compositions including at least two different inert fillers that are useful for preparing prepregs and laminates that are used in manufacturing printed circuit boards.
1. A resin composition comprising:
styrene maleic anhydride co-polymer;
at least one epoxy resin;
at least one cross-linking agent;
talc present in the resin in an amount ranging from bout 2.5 to about 15 wt % on a dry basis; and
silica present in the resin in an amount ranging from about 2.5 to about 25 wt % on a dry basis;
wherein the weight ratio of silica to talc is in the range from about 1:2.5 to about 5:1.
2. The resin of claim 1 wherein the silica is fused silica.
3. The resin of claim 1 wherein the silica is a silated silica.
4. The resin of claim 1 wherein the talc is a silated talc.
5. The resin of claim 1 including from about 5 to about 12.5 wt % talc and from about 5 to about 25 wt % of silated fused silica each on a dry weight basis.
6. The resin of claim 1 wherein the styrene maleic anhydride co-polymer is present in the resin in an amount ranging from about 5 to about 40 wt % on a dry solvent free resin basis.
7. The resin of claim 1 wherein the at least one epoxy resin is present in the resin in an amount ranging from about 10 to about 50 wt % on a dry solvent free resin basis.
8. The resin of claim 1 wherein the at least one epoxy resin is selected from a brominated bisphenol A, a brominated bisphenol F, a non-brominated bisphenol A, a non-brominated bisphenol F and combinations thereof.
9. The resin of claim 1 wherein the at least one cross-linking agent is present in the resin in an amount ranging from greater than 0 to about 20 wt % on a dry solvent free resin basis.
10. The resin of claim 1 wherein the at least one cross-linking agent is selected from tetrabromobisphenol A, tetra-DOPO-bisphenol A or a mixture thereof.
11. The resin of claim 1 including from about 0.01 to about 3.0 wt5 on a dry solvent free resin basis of at least one azo-type catalyst.
12. The resin of claim 1 including a catalyst selected from azobisisobutyronitrile, 2-propyl imidiazole, tetrabutylphophonium acid acetate, 2-methylimidazole and combinations thereof.
13. A resin composition comprising:
from about 15 to about 35 wt % on a dry solvent free resin basis of a styrene maleic anhydride co-polymer;
from about 5 to about 45 wt % on a dry solvent free resin basis of at least one epoxy resin selected from a brominated bisphenol A epoxy resin, a brominated bisphenol F epoxy resin, a non-brominated bisphenol A epoxy resin, a non-brominated bisphenol F epoxy resin or a combinations thereof;
from about greater than 0.5 to about 10 wt % on a dry solvent free resin basis of at least one cross-linking agent selected from tetrabromobisphenol A, tetra-DOPO-bisphenol A and mixtures thereof;
from about 2.5 to about 12.5 wt % on a dry resin basis of talc; and
from about 2.5 to about 12.5 wt % on a dry resin basis of fumed silica.
14. The resin composition of claim 13 wherein the weight ratio of fumed silica to talc ranges from 1:2.5 to 5:1.
15. The resin composition of claim 13 wherein the weight ratio of fumed silica to talc ranges from 1:1 to 2.5:1.
16. The resin composition of claim 15 wherein the fumed silica is an amorphous silated fumed silica.
17. The resin composition of claim 13 wherein the talc is silated talc.