Adhesion-promoting system for rubber goods
The invention relates a mixture of a urethane-aldehyde resin UA prepared by condensation of an aldehyde A1 and an alkyl urethane U, and of a novolak PA, to a process for the preparation of the said mixture, and a method of use thereof as adhesion promoter in rubber goods.
1. A mixture of a urethane-aldehyde resin UA prepared by condensation of an aldehyde A1 and an alkyl urethane U, and of a novolak PA prepared by reaction of an aldehyde A2 with a phenolic compound P wherein
the aldehydes A1 and A2 are independently selected from the group consisiting of formaldehyde, acetaldehyde, propionic aldehyde, butyric aldehyde, and isobutyric aldehyde,
the alkyl urethane U is selected from the group consisting of ethyl urethane, butyl urethane, 2-ethylhexyl urethane, and decyl urethane,
the phenolic compound P is selected from the group consisting of phenol, o-, m-, and p-cresol, o-, m-, and p-monoalkylphenols with alkyl radicals up to 18 carbon atoms, and
the mass ratio of the urethane aldehyde resin UA and the novolak PA is from 90 g:10 g to 10 g:90 g.
2. The mixture of claim 1 , wherein the alkyl urethane U is butyl urethane.
3. The mixture of claim 1 , wherein the aldehyde A1 used for the preparation of the urethane aldehyde resins UA is formaldehyde.
4. The mixture of claim 1 , wherein the phenolic compound P is phenol.
5. The mixture of claim 1 , wherein the aldehyde A2 is formaldehyde.
6. The mixture of claim 1 , wherein the mass ratio of the urethane aldehyde resin UA and the novolak PA is from 10 g:90 g to 35 g:65 g.
7. A process for the preparation of the mixture of claim 1 , wherein the novolak PA is prepared by reaction of an aldehyde A2 selected from the group consisting of formaldehyde, acetaldehyde, propionic aldehyde, butyric aldehyde, and isobutyric aldehyde with a phenolic compound P, selected from the group consisting of phenol, o-, m-, and p-cresol, o-, m-, and p-monoalkylphenols with alkyl radicals up to 18 carbon atoms, in the presence of a urethanealdehyde resin UA prepared by condensation of an aldehyde A1 and an alkyl urethane U, wherein the aldehyde A1 is selected from the group consisting of formaldehyde, acetaldehyde, propionic aldehyde, butyric aldehyde, and isobutyric aldehyde, and the alkyl urethane U is selected from the group consisting of ethyl urethane, butyl urethane, 2-ethylhexyl urethane, and decyl urethane.
8. A vulcanisable rubber blend containing at least one rubber, reinforcing agents which are reinforcing fibres or filaments or wires, vulcanising agents, curing agents, fillers and additives and the mixture of a urethane aldehyde resin UA and a novolak PA as claimed in claim 1 .
9. The vulcanisable rubber blend of claim 8 , wherein the mass fraction of the said mixture of a urethane aldehyde resin UA and a novolak PA in the vulcanisable rubber blend is up to 20%, based on the mass of the vulcanisable rubber blend.
10. A vulcanisable rubber blend containing at least one rubber, reinforcing agents which are reinforcing fibres or filaments or wires, vulcanising agents, curing agents, fillers and additives and a mixture of a urethane aldehyde resin UA and a novolak PA, wherein the novolak PA is prepared by the process of claim 7 .
11. The vulcanisable rubber blend of claim 10 , wherein the mass fraction of the said mixture of a urethane aldehyde resin UA and a novolak PA in the vulcanisable rubber blend is up to 20%, based on the mass of the vulcanisable rubber blend.