DRYING AGENT FOR MOISTURE-CURING COMPOSITIONS

1 . A polymer composition produced by:

a) reacting an NCO-reactive polymer having at least two NCO-reactive groups per molecule with a polyisocyanate, a molar ratio of the polyisocyanate molecules to the NCO-reactive groups of the NCO-reactive polymer being at least 1.25:1;

and subsequently

b) reacting remaining NCO groups in a reaction product from step a) with an NCO-reactive silane.

2 . The polymer composition as claimed in claim 1 , wherein the molar ratio of the polyisocyanate molecules to the NCO-reactive groups of the NCO-reactive polymer in (a) is 1.25:1 to 10:1.

3 . The polymer composition as claimed in claim 1 , wherein the NCO-reactive polymer has a number-average molecular weight of 2000 to 100 000 g/mol.

4 . The polymer composition as claimed in claim 1 , wherein the NCO-reactive polymer is a polyol.

5 . The polymer composition as claimed in claim 1 , wherein the polyisocyanate comprises 1,4-diisocyanatobutane, 1,5-diisocyanatopentane, hexamethylene 1,6-diisocyanate (HDI), 2-methyl-1,5-diisocyanatopentane, 1,5-diisocyanato-2,2-dimethylpentane, 2,2,4- and/or 2,4,4-trimethyl-1,6-diisocyanatohexane, 1,10-diisocyanatodecane, 1,3- and/or 1,4-diisocyanatocyclohexane, 1,4-diisocyanato-3,3,5-trimethylcyclohexane, 1,3-diisocyanato-2-methylcyclohexane, 1,3-diisocyanato-4-methylcyclohexane, 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane, 1-isocyanato-1-methyl-4(3)-isocyanatomethylcyclohexane, 2,4′- and/or 4,4′-diisocyanatodicyclohexylmethane, 1,3- and/or 1,4-bis(isocyanatomethyl)cyclohexane, bis(isocyanatomethyl)norbornane, 4,4′-diisocyanato-3,3′-dimethyldicyclohexylmethane, 4,4′-diisocyanato-3,3′,5,5′-tetramethyldicyclohexylmethane, 4,4′-diisocyanato-1,1′-bis(cyclohexyl), 4,4′-diisocyanato-3,3′-dimethyl-1,1′-bi(cyclohexyl), 4,4′-diisocyanato-2,2′,5,5′-tetramethyl-1,1′-bi(cyclohexyl), 1,8-diisocyanato-p-menthane, 1,3-diisocyanatoadamantane, 1,3-dimethyl-5,7-diisocyanatoadamantane, 1,3- and/or 1,4-bis(isocyanatomethyl)benzene, 1,3- and/or 1,4-bis(1-isocyanato-1-methylethyl)benzene, bis(4-(1-isocyanato-1-methylethyl)phenyl) carbonate, 2,4- and/or 2,6-diisocyanatotoluene, 2,4′- and/or 4,4′-diisocyanatodiphenylmethane, 1,5-diisocyanatonaphthalene, or a mixture thereof.

6 . The polymer composition as claimed in claim 1 , wherein the NCO-reactive silane is a compound of formula (I):

R 1 3 Si(CH 2 ) n X   (I),

wherein

R 1 each radical is in each case independently selected from C 1 -C 8 -alkyl, C 6 -C 20 -aryl, C 1 -C 8 -alkoxy, or C 1 -C 8 -acyloxy and at least one of the radicals R 1 is a C 1 -C 8 -alkoxy or C 1 -C 8 -acyloxy radical,

n is an integer from 1 to 4,

X is selected from —OH, —SH, and —NHR 2 ,

R 2 is selected from H, C 1 -C 20 -alkyl, —CH 2 CH 2 CN, and —CHR 3 CH 2 COOR 4 ,

R 3 is selected from H and —COOR 4 , and

R 4 in each case is C 1 -C 20 -alkyl.

7 . A process for producing the polymer composition as claimed in claim 1 , comprising:

a) reacting an NCO-reactive polymer having at least two NCO-reactive groups per molecule with a polyisocyanate, a molar ratio of the polyisocyanate molecules to the NCO-reactive groups of the NCO-reactive polymer being at least 1.25:1; and

b) reacting a reaction product from step a) with an NCO-reactive silane.

8 . A moisture-curing composition comprising a polymer composition as claimed in claim 1 and at least one additive comprising one or more fillers, one or more crosslinking catalysts, one or more adhesion promoters, one or more plasticizers, or a combination thereof.

9 . The moisture-curing composition as claimed in claim 8 , wherein the moisture-curing composition has a water content, determined according to DIN EN ISO 15512:2017-03, method B2, of up to 0.1% by weight, based on a total weight of the moisture-curing composition.

10 . The moisture-curing composition as claimed in claim 8 , containing no further drying agents.

11 . The moisture-curing composition as claimed in claim 8 , comprising less than 1% by weight of vinyl group-containing silanes, based on a total weight of the moisture-curing composition.

12 . The moisture-curing composition as claimed in claim 8 , comprising

5% to 50% by weight of the polymer composition as claimed in claim 1 ;

10% to 70% by weight of at least one filler;

up to 5% by weight of at least one adhesion promoter;

0.001% to 5% by weight of at least one crosslinking catalyst; and

up to 50% by weight of at least one plasticizer,

based in each case on a total weight of the moisture-curing composition.

13 . A process for producing the a moisture-curing composition, comprising mixing a polymer composition as claimed in claim 1 with at least one filler, at least one adhesion promoter, at least one crosslinking catalyst, at least one plasticizer, or a combination thereof.

14 . The process as claimed in claim 13 , wherein the polymer composition as claimed in claim 1 is mixed with at least one filler having a water content of up to 1% by weight, based on a total weight of the filler.

15 . The process as claimed in claim 13 , wherein at most 1% by weight of vinyl group-containing silanes are added to the moisture-curing composition.

16 . A drying agent for moisture-curing adhesives, sealants, or coating materials, comprising the polymer composition as claimed in claim 1 .

17 . A parquet adhesive containing the polymer composition as claimed in claim 1 .