Two-step method for dipping synthetic fiber
A two-step method for dipping a synthetic fiber includes the fiber being first dipped with an aqueous pre-dip composition followed by a dip with resorcinol-formaldehyde latex (RFL) composition, wherein the pre-dip composition includes a blocked isocyanate having at least tri-functional isocyanate groups and a latex wherein the ratio by weight of blocked isocyanate and latex is in the range of 9 to 0.7, preferably in the range of 4 to 1. A pre-dip composition for dipping a synthetic fiber includes a blocked at least tri-functional isocyanate compound and a latex, further including water, an emulsifier, and 2-vinyl pyridine copolymer and to a fiber, cord, and composite article of rubber and fiber or cord, wherein the fiber or cord has distributed over at least a surface portion thereof (1) blocked tri-functional isocyanate compound, preferably HDI-trimer; (2) an RFL adhesive; and (3) an in situ vulcanized rubber compound.
1 . A two-step method for dipping a synthetic fiber, comprising dipping the fiber in an aqueous pre-dip composition followed by dipping in a resorcinol-formaldehyde latex (RFL) composition, wherein the aqueous pre-dip composition comprises a blocked isocyanate having at least tri-functional isocyanate groups and a latex and wherein a ratio by weight of blocked isocyanate to latex is in the range of from about 9 to about 0.7.
2 . The method according to claim 1 wherein the pre-dip composition is substantially free from epoxide-containing derivatives.
3 . The method according to claim 1 wherein the latex part of the pre-dip composition and of the RFL composition comprises block copolymers of a conjugated olefinic block and an aromatic block.
4 . The method according to claim 3 wherein the latex part is a vinyl-pyridine block copolymer.
5 . The method according to claim 1 wherein the synthetic fiber is a fiber containing at least one of aramid, polyester, and polyester terephthalate.
6 . The method according to claim 5 wherein the synthetic fiber is a fiber containing at least aramid.
7 . The method according to claim 1 wherein as the synthetic fiber is an as spun fiber.
8 . The method according to claim 1 wherein the blocked isocyanate is a blocked HDI-trimer.
9 . A pre-dip composition for dipping a synthetic fiber, comprising a blocked at least tri-functional isocyanate compound and a latex, further comprising water, an emulsifier, and 2-vinyl pyridine copolymer.
10 . A fiber or cord, wherein the fiber or cord has distributed over at least a surface portion thereof (1) a blocked at least tri-functional isocyanate compound, (2) an RFL adhesives and (3) an in situ vulcanized rubber compound.
11 . A composite article comprising rubber and the fiber or cord according to claim 10 .
12 . The method according to claim 1 wherein the ratio by weight of blocked isocyanate to latex is in the range of from about 4 to about 1.
13 . The method according to claim 1 wherein the synthetic fiber is a fiber containing at least PPTA or PPODPTA.
14 . The method according to claim 2 wherein the latex part of the pre-dip composition and of the RFL composition comprises block copolymers of a conjugated olefinic block and an aromatic block.
15 . The method according to claim 14 wherein the latex part is a vinyl-pyridine block copolymer.
16 . The fiber or cord according to claim 10 wherein the blocked at least tri-functional isocyanate compound is a HDI-trimer.