Filter media saturating resole resin
An improved resole resin for producing filter media, e.g., paper, especially useful for automotive applications comprising a bisphenol-modified phenol-formaldehyde resin prepared using an amine catalyst.
1 . A resole resin composition comprising the reaction product of formaldehyde (F), phenol (P) and a bisphenol in an F:P mol ratio in the range of 1:1 to 2.2:1, said formaldehyde, phenol and bisphenol being reacted in the presence of an amine catalyst.
2 . A filter medium impregnated with a B-staged resole resin composition wherein the resole resin composition comprises the reaction product of formaldehyde (F), phenol (P) and a bisphenol in an F:P mol ratio in the range of 1:1 to 2.2:1, said formaldehyde, phenol and bisphenol being reacted in the presence of an amine catalyst.
3 . A filter comprising a filter medium impregnated with a cured resole resin composition wherein the resole resin composition comprises the reaction product of formaldehyde (F), phenol (P) and a bisphenol in an F:P mol ratio in the range of 1:1 to 2.2:1, said formaldehyde, phenol and bisphenol being reacted in the presence of an amine catalyst.
4 . In a process for producing a resole resin-impregnated filter medium in which a filter medium is saturated with a resole resin prepared from phenol, a bisphenol and formaldehyde, the resole resin is B-staged, and then the B-staged resin is cured, the improvement comprising using a resole resin prepared in the presence of an amine catalyst.
5 . A composition for impregnating a filter medium comprising a mixture in an organic solvent of (A) a resole resin comprising the reaction product of formaldehyde (F), phenol (P) and a bisphenol in an F:P mol ratio in the range of 1:1 to 2.2:1, said formaldehyde, phenol and bisphenol being reacted in the presence of an amine catalyst and (B) a novolac resin.
6 . A filter medium impregnated with the composition of claim 5 wherein the resole resin has been B-staged.
7 . A filter comprising a filter medium impregnated with the composition of claim 5 wherein the resole resin has been cured.
8 . The invention of claim 1 , 2 , 3 or 4 wherein the bisphenol is bisphenol-A.
9 . The invention of claim 8 wherein the amine catalyst is triethylamine.
10 . The invention of claim 5 , 6 or 7 wherein the bisphenol is bisphenol-A.
11 . The invention of claim 10 wherein the catalyst is triethylamine.
12 . The invention of claim 11 wherein the resole resin (A) and the novolac resin (B) are used in a solids weight ratio (A:B) in the range of 50:50 to 80:20.
13 . The invention of claim 9 wherein the bisphenol is included in an amount of 1 to 18 parts by weight per 100 parts by weight of phenol.
14 . The invention of claim 12 wherein the bisphenol is included in an amount of 1 to 18 parts by weight per 100 parts by weight of phenol.