Moisture curable polymer systems based on a mixture of polysilylated polyethers

Patent metadata

Field	Value
Publication number	US-10239998-B2
Application number	US-201515533364-A
Country	US
Kind code	B2
Filing date	Dec 5, 2015
Priority date	Dec 22, 2014
Publication date	Mar 26, 2019
Grant date	Mar 26, 2019

Abstract

Low viscosity mixtures of polysilylated polyethers are described. The mixtures include a) 50 to 95 weight percent of one or more first polysilylated polyethers which are free of urea groups, have an average of two or more terminal hydrolysable silyl groups per molecule and have a molecular weight of 4,000 to 20,000 and 50 to 5 weight percent of one or more second polysilylated polyethers which are free of urea groups, have an average of 1.8 to 4 terminal hydrolysable silyl groups per molecule and have a molecular weight of 1000 to less than 400. The mixtures have surprisingly low viscosities, and are useful as curable components of adhesive, sealant, caulking and/or coating compositions.

First claim

What is claimed is:

1. A moisture-curable polysilylated polyether composition comprising a mixture of polysilylated polyethers, wherein the mixture comprises
a) 50 to 95 weight percent, based on the combined weights of a) and b), of one or more first polysilylated polyethers which are free of urea groups, have an average of two or more terminal hydrolysable silyl groups per molecule and have a molecular weight of 4,000 to 20,000, the first polysilylated polyether(s) being a reaction product of a i) linear polyether having a terminal isocyanate group, a terminal hydrolysable silyl group and a number average molecular weight of 250 to 2000 and (ii) a polyether polyol nominally having 2 to 6 hydroxyl groups per molecule and a hydroxyl equivalent weight of 500 to 2500; and
b) 50 to 5 weight percent, based on the combined weights of a) and b), of one or more second polysilylated polyethers which are free of urea groups, have an average of 1.8 to 4 terminal hydrolysable silyl groups per molecule and have a molecular weight of 1000 to less than 4,000, the second polysilylated polyether(s) being a reaction product of i) a linear monosilylated polyether monol having a terminal hydroxyl group, a terminal hydrolysable silyl group and a molecular weight of 250 to 1500 and ii) a coupling agent having at least two groups reactive with hydroxyl groups and a molecular weight of up to 500.

2. The moisture-curable polysilylated polyether composition of claim 1 which comprises 60 to 90 weight percent of component a) and correspondingly 40 to 10 weight percent of component b) based on the combined weights of components a) and b).

3. The moisture-curable polysilylated polyether composition of claim 2 which has a viscosity of 5 to 50 Pa·s at 25° C.

4. The moisture-curable polysilylated polyether composition of claim 3 wherein component a) is one or more compounds represented by the structure (I):

where A is either H or has the structure (II):

k is a number from 0 to 4, m and n are independently numbers from 0 to 3, the values of x and y are numbers such that the compound has a molecular weight of 4000 to 20,000, R 1 , R 2 , R 10 and R 11 are independently straight chain or branched alkyl groups having 1 to 4 carbon atoms, R 3 , R 4 , R 5 , R 6 , R 8 and R 9 are independently hydrogen or straight chain or branched alkyl groups having 1 to 4 carbon atoms, and R7 is aliphatic, cycloaliphatic, bis-benzylic and/or aromatic and has 2 to 20 carbon atoms.

5. The moisture-curable polysilylated polyether composition of claim 4 wherein component b) is one or more compounds represented by the structure

wherein R 8 , R 9 , R 11 are independently straight chain or branched alkyl groups having 1 to 4 carbon atoms, R 10 is a straight chain or branched alkylene group having 1 to 4 carbon atoms, y is a number such that the molecular weight of the second silylated polyether is 1000 to less than 4000, R 12 is the residue, after removal of isocyanate groups, of a polyisocyanate having z isocyanate groups and a molecular weight of up to 500, and z has an average value of 1.8 to 4.

6. The moisture-curable polysilylated polyether composition of claim 5 wherein component a) has a molecular weight of 6000 to 13,000 and an average of 3 to 4 hydrolysable silyl groups per molecule.

7. The moisture-curable polysilylated polyether composition of claim 6 wherein component b) has a molecular weight of 1200 to 3000 and an average of 1.8 to 2.5 hydrolysable silyl groups per molecule.

8. A method for making a moisture-curable polysilylated polyether composition of claim 1 , comprising the steps of
A) forming a mixture of:
starting material 1): one or more first polysilylated polyethers free of urea groups, having an average of two or more terminal hydrolysable silyl groups per molecule and having a molecular weight of 4,000 to 20,000, the first polysilylated polyether(s) being a reaction product of a i) linear monosilylated polyether isocyanate having a terminal isocyanate group, a terminal hydrolysable silyl group and a molecular weight of 500 to 2000 and (ii) at least one polyether polyol nominally having 2 to 6 hydroxyl groups per molecule and a hydroxyl equivalent weight of 500 to 2500;
starting material 2): at least one linear monosilylated polyether monol having a terminal hydroxyl group, a terminal hydrolysable silyl group and a molecular weight of 250 to 1500; and
starting material 3): at least one coupling agent having at least two groups reactive with hydroxyl groups and a molecular weight of up to 500; and
B) reacting starting material 2 and 3) in the presence of starting material 1) to produce a mixture of starting material 1) and at least one second polysilylated polyether having a molecular weight of 1000 to less than 4000 and an average of 1.8 to 4 terminal hydrolysable silyl groups per molecule and corresponding to a reaction product of starting material 2) with starting material 3).

9. A formulated adhesive, sealant, caulking or coating composition comprising the moisture-curable polysilylated polyether composition of claim 1 and at least 5 weight percent, based on the weight of the moisture-curable polysilylated polyether composition, of at least one mineral filler.

10. The formulated adhesive, sealant, caulking or coating composition of claim 9 which contains 10 to 50 weight percent, based on the weight of the moisture-curable polysilylated polyether composition, of the at least one mineral filler.

11. The formulated adhesive, sealant, caulking or coating composition of claim 10 , which has a viscosity of 5 to 1000 Pa·s at 25° C.

12. A method for making a moisture-curable polysilylated polyether composition, comprising the steps of
(I) Forming a first reaction mixture containing at least one starting linear monosilylated polyether monol having a terminal hydroxyl group, a terminal hydrolysable silyl group and a molecular weight of 250 to 1500 and at least one diisocyanate and a molecular weight of up to 500, the linear monosilylated polyether monol and polyisocyanate being provided in amounts such that greater than one equivalent of isocyanate groups is provided per equivalent of hydroxyl groups on the linear monosilylated polyether monol;
II) reacting the first reaction mixture from step I to form a reaction product containing i) at least one linear monosilylated polyether isocyanate having a terminal isocyanate group, a terminal hydrolysable silyl group and a molecular weight of 500 to 2000 and ii) a polysilylated polyether having at least two terminal hydrolysable silyl groups and a molecular weight of 1000 to less than 4000, which polysilylated polyether lacks isocyanate groups and corresponds to a reaction product of the polyisocyanate with one molecule of the starting linear polyether per isocyanate group of the stating polyisocyanate;
(III) combining the reaction product formed in step II) with at least one polyether polyol nominally having 2 to 6 hydroxyl groups per molecule and a hydroxyl equivalent weight of 500 to 2500 to form a second reaction mixture, and
(IV) reacting the polyether polyol(s) and the linear monosilylated polyether isocyanate in the second reaction mixture in the presence of the polysilylated polyether formed in step II to produce a mixture of polysilylated polyethers.

Assignees

• Dow Global Technologies Llc

Inventors

• Willumstad Thomas
• Jagtap Subodh P

Classifications

• C08G18/289

  containing silicon · CPC title

• C08G65/336 Primary

  containing silicon · CPC title

• C08L101/10

  containing hydrolysable silane groups · CPC title

• C08G65/33348 Primary

  containing isocyanate group · CPC title

• C08G65/3348

  containing nitrogen in addition to sulfur · CPC title