Aqueous adhesive composition for the bonding of wood
View Patent ↗An aqueous adhesive composition comprises a phenol/aldehyde resin and less than 16% by weight of unsaturated diene elastomer latex. The phenol/aldehyde resin is based on an aromatic polyaldehyde bearing at least two aldehyde functional groups and comprising at least one aromatic nucleus, and on a polyphenol comprising one or more aromatic nuclei. If just one aromatic nucleus is present, the latter bears two or three hydroxyl functional groups in the meta position with respect to one another and the remainder of the aromatic nucleus is unsubstituted. If several aromatic nuclei are present, at least two of them each bear two or three hydroxyl functional groups in the meta position with respect to one another, it being understood that the two positions ortho to at least one of these hydroxyl functional groups are unsubstituted.
1. An aqueous adhesive composition comprising:
a phenol/aldehyde resin based on:
at least one aromatic polyaldehyde bearing at least two aldehyde functional groups and comprising at least one aromatic nucleus, and
at least one polyphenol comprising one or more aromatic nuclei,
wherein if only one aromatic nucleus is present, the only one aromatic nucleus bears two or three hydroxyl functional groups in the meta position with respect to one another and a remainder of the aromatic nucleus is unsubstituted, and
wherein if more than one aromatic nuclei are present, at least two of the more than one aromatic nuclei each bear two or three hydroxyl functional groups in the meta position with respect to one another and the two positions ortho to at least one of the hydroxyl functional groups are unsubstituted; and
less than 16% by weight of unsaturated diene elastomer latex.
2. The composition according to claim 1 , wherein the composition contains at most 10% by weight of unsaturated diene elastomer latex.
3. The composition according to claim 2 , wherein the composition contains at most 5% by weight of unsaturated diene elastomer latex.
4. The composition according to claim 3 , wherein the composition contains at most 1% by weight of unsaturated diene elastomer latex.
5. The composition according to claim 1 , wherein the aromatic nucleus of the at least one aromatic polyaldehyde bears two aldehyde functional groups.
6. The composition according to claim 1 , wherein the aromatic nucleus of the at least one aromatic polyaldehyde is a benzene nucleus.
7. The composition according to claim 1 , wherein the at least one aromatic polyaldehyde is selected from the group consisting of 1,2-benzenedicarboxaldehyde, 1,3-benzenedicarboxaldehyde, 1,4-benzenedicarboxaldehyde, 2-hydroxybenzene-1,3,5-tricarbaldehyde and mixtures thereof.
8. The composition according to claim 7 , wherein the at least one aromatic polyaldehyde is selected from the group consisting of 1,3-benzenedicarboxaldehyde, 1,4-benzenedicarboxaldehyde and mixtures thereof.
9. The composition according to claim 8 , wherein the at least one aromatic polyaldehyde is 1,4-benzenedicarboxaldehyde.
10. The composition according to claim 1 , wherein, if only one aromatic nucleus is present in the at least one polyphenol, the only one aromatic nucleus is a benzene nucleus.
11. The composition according to claim 1 , wherein, if more than one aromatic nuclei are present in the at least one polyphenol, each nucleus bearing two or three hydroxyl functional groups in the meta position with respect to one another is a benzene nucleus.
12. The composition according to claim 1 , wherein the at least one polyphenol is selected from the group consisting of phloroglucinol, 2,2′,4,4′-tetrahydroxydiphenyl sulphide and mixtures thereof.
13. A process for the manufacture of an aqueous adhesive composition according to claim 1 comprising the step of mixing the at least one polyphenol and the at least one aromatic polyaldehyde in an aqueous solution.
14. The process according to claim 13 , wherein the aqueous solution has a pH ranging from 9 to 13.
15. The process according to claim 14 , wherein the aqueous solution has a pH ranging from 10 to 12.
16. A process for the adhesive bonding of two wood elements comprising the steps of:
applying a layer of the aqueous adhesive composition according to claim 1 to at least one of the two wood elements; and
joining the two wood elements to one another via the layer of the aqueous adhesive composition.
17. An adhesively-bonded assemblage of two wood elements comprising a layer of the aqueous adhesive composition according to claim 1 joining the two wood elements to each other.