Method for laying parquet flooring with improved dimensional stability

1. A moisture-crosslinkable adhesive composition comprising:

from 25% to 50% of a composition (a):

of 5% to 37% weight/weight of a crosslinkable epoxy resin (a1) of bisphenol A type, and

of 63% to 95% weight/weight of a polymer (a2) comprising a main chain of (i) a polyoxyalkylene or (ii) a polyurethane, which is connected to two hydrolyzable terminal alkoxysilyl groups, said groups being bonded, in the case of a main chain (i), to a methylene radical which is itself bonded to the ends of the chain (i) by a divalent group A having one of the following formulae:

—O—CO—NH—  (Ia);

—NR 1 —CO—NH—  (Ib),

in which R 1 represents a hydrogen atom or a C 1 -C 3 alkyl radical; and

—S—CO—NH—  (Ic);

from 0.5% to 6% of a ketimine (b) as precursor of a crosslinking agent for the epoxy resin (a1); and

from 40% to 65% of an inert inorganic or organic filler (c);

the contents of ingredients (a), (b) and (c) being expressed as weight/weight percentages with respect to the total weight of said adhesive composition, wherein the hydrolysable terminal alkoxysilyl groups have the formula:

—Si(R 2 ) p (OR 3 ) 3−p   (II)

in which:

each R 2 and R 3 independently represents a linear or branched alkyl radical of 1 to 4 carbon atoms; and

P=1.

2. The adhesive composition as claimed in claim 1 , wherein crosslinkable epoxy resin (a1), is bisphenol A diglycidyl ether of formula:

3. The adhesive composition as claimed in claim 1 , wherein the polymer (a2) has a polypropylene glycol main chain (i) and the divalent group A is of formula (Ia).

4. The adhesive composition as claimed in claim 1 , wherein the polymer (a2) has a polyurethane (ii) for main chain.

5. The adhesive composition as claimed in claim 1 , wherein the content of crosslinkable epoxy resin (a1) included in the composition (a) is 10% to 33% and the content of polymer (a2) in this same composition is 67% to 90%.

6. The adhesive composition as claimed in claim 1 , wherein the ketimine (b) has the formula:

(R 6 R 7 C═N) q R 5   (IV)

in which:

R 5 is an organic radical having from 1 to 3 free valences;

R 6 and R 7 , which are identical or different, represent a hydrogen atom, a phenyl group or an alkyl group having 1 to 6 carbon atoms, which is optionally substituted;

q is an integer equal to 1, 2 or 3.

7. The adhesive composition as claimed in claim 6 , wherein the ketimine (b) has formula (IV) in which q is equal to 2, R 5 is a divalent radical derived from isophorone, R 6 is methyl and R 7 is isobutyl.

8. The adhesive composition as claimed in claim 6 , wherein R 5 is optionally substituted C 1-12 -alkyl or C 6-24 -aryl.

9. The adhesive composition as claimed in claim 1 , wherein the inorganic filler (c) is calcium carbonate or a fumed silica.

10. The adhesive composition as claimed in claim 1 , comprising:

a content of the composition (a) of 30% to 40%;

a content of ketimine (b) of 1% to 5%; and

a content of the inorganic filler (c) of 50% to 60%.

11. The adhesive composition as claimed in claim 1 , wherein the polymer (a2) has a polyoxyalkylene (i) for main chain and divalent group A is of formula (Ia).

12. The adhesive composition as claimed in claim 1 , wherein polymer (a2) has the formula (R 3 O) 2 (R 2 )Si—CH 2 —NH—C(O)—O-polyoxyalkylene-C(O)NH—CH 2 —Si(R 2 )(OR 3 ) 2 wherein each R 2 and R 3 independently represents a linear or branched alkyl radical comprising 1 to 4 carbon atoms; and

wherein the polyoxyalkylene corresponds to a repeat unit of —R 4 —O—, in which R 4 represents a linear or branched alkylene comprising from 1 to 5 carbon atoms.

13. A method for laying a wood-based covering on a flat rigid support, comprising distributing, over the surface of said support, an effective amount of the adhesive composition as defined in claim 1 .

14. The laying method as claimed in claim 13 , wherein the wood-based covering is a parquet flooring.

15. The laying method as claimed in claim 13 , wherein the adhesive composition is distributed over the support in the form of a substantially homogeneous layer.

16. An assemblage comprising a flat rigid support covered with a wood-based covering via a substantially homogeneous layer of the adhesive composition, as defined in claim 1 , which is crosslinked and forms an adhesive joint.

17. The assemblage as claimed in claim 16 , wherein the covering is a parquet flooring that can be used as a floor.