Process for preparing clustered functional polyorganosiloxanes, and methods for their use

Patent metadata

Field	Value
Publication number	US-9593209-B2
Application number	US-201013508375-A
Country	US
Kind code	B2
Filing date	Nov 3, 2010
Priority date	Oct 22, 2009
Publication date	Mar 14, 2017
Grant date	Mar 14, 2017

Abstract

A hydrosilylation process is used to prepare a polyorganosiloxane having clustered functional groups at the polyorganosiloxane chain terminals. The ingredients used in the process include a) a polyorganosiloxane having an average of at least 2 aliphatically unsaturated organic groups per molecule, b) a polyorganohydrogensiloxane having an average of 4 to 15 silicon atoms per molecule and at least 4 silicon bonded hydrogen atoms for each aliphatically unsaturated organic group in ingredient a), c) a reactive species having, per molecule at least 1 aliphatically unsaturated organic group and 1 or more curable groups; and d) a hydrosilylation catalyst. The resulting clustered functional polyorganosiloxane is useful in a curable silicone composition for electronics applications.

First claim

The invention claimed is:

1. A process comprising:
1) concurrently reacting ingredients comprising
a) a polyorganosiloxane having an average per molecule of at least 2 aliphatically unsaturated organic groups,
b) a polyorganohydrogensiloxane having an average, per molecule, of 4 to 15 silicon atoms and at least 4 silicon bonded hydrogen atoms per aliphatically unsaturated organic group in ingredient a), and
c) a reactive species having, per molecule at least one aliphatically unsaturated organic group and one or more curable groups;

in the presence of d) a hydrosilylation catalyst; and
optionally one of e) a filler, f) a non-reactive silicone resin, or a combination thereof; and
further optionally g) a chain extender, h) an endcapper, or both;

with the proviso that a ratio of
silicon bonded hydrogen atoms in ingredient b) divided by the number of aliphatically unsaturated organic groups in ingredient a) (the SiH b /Vi a ratio)
ranges from 4/1 to 20/1 and a product prepared by the process has more than one curable group at each terminus of the polyorganosiloxane of ingredient a) and where ingredient c) provides two or more different types of curable groups and the product is deemed a multiple cure clustered functional polyorganosiloxane; and
optionally 2) adding a catalyst inhibitor, and
when step 2 ) is present, further optionally 3) purifying the product of step 2 ).

2. The process of claim 1 , where ingredient a) and ingredient b) are present in amounts sufficient to provide the SiH b /Vi a ratio with a value ranging from 4/1 to 10/1.

3. The process of claim 1 where the filler is present, and the filler is added by a method comprising: mixing the filler, a filler treating agent, and all or a portion of ingredient a) before step 1 ).

4. The process of claim 1 , where ingredient a) has a formula selected from the group consisting of formula (I), formula (II), and a combination thereof, where
formula (I) is R 1 2 R 2 SiO(R 1 2 SiO) a (R 1 R 2 SiO) b SiR 1 2 R 2 ,
formula (II) is R 1 3 SiO(R 1 2 SiO) c (R 1 R 2 SiO) d SiR 1 3 ;
each R 1 is independently a monovalent organic group free of aliphatic unsaturation,
each R 2 is independently an aliphatically unsaturated organic group,
subscript a has an average value ranging from 2 to 1000,
subscript b has an average value ranging from 0 to 1000,
subscript c has an average value ranging from 0 to 1000, and
subscript d has an average value ranging from 4 to 1000;
with the provisos that 10 ≦(a +b) ≦1000 and 10≦(c +d) ≦1000.

5. The process of claim 1 , where ingredient b) is selected from:
i) a cyclic polyorganohydrogensiloxane;
ii) a branched polyorganohydrogensiloxane;
iii) a linear polyorganohydrogensiloxane having an average of at least 4 silicon bonded hydrogen atoms per molecule;
iv) a polyorganohydrogensiloxane having formula (III), where formula (III) is (R 3 2 SiO 2/2 ) e (HR 3 SiO 2/2 ) f , where
each R 3 is independently a monovalent organic group free of aliphatic unsaturation,
subscript e has an average value ranging from 0 to 10,
subscript f has an average value ranging from 3 to 12, and
a sum (e +f) has a value ranging from 3 to 12;

v) a polyorganohydrogensiloxane having formula (IV), where formula (IV) is Si—(OSiR 4 2 ) g (OSiHR 4 ) g ,(OSiR 4 3 H) h (OSiR 4 2 H) (4-h) , where
each R 4 is independently a monovalent organic group free of aliphatic unsaturation,
subscript g has a value ranging from 0 to 10,
subscript g′ has a value ranging from 0 to 10, and
subscript h has a value ranging from 0 to 1;
with the proviso that when subscript g′ is 0 , then subscript h is also 0;

vi) a polyorganohydrogensiloxane having formula (V), where formula (V) is SiR
R 5 2 HSiO(R 5 2 SiO) i (R 5 HSiO) j SiR 5 2 H, where
each R 5 is independently a monovalent organic group free of aliphatic unsaturation,
subscript i has an average value ranging from 1 to 12,
subscript j has an average value ranging from 2 to 12, and
a sum (i +j) has a value ranging from 4 to 13;

vii) a polyorganohydrogensiloxane having formula (VI), where formula (VI) is R 5 3 SiO(R 5 2 SiO) k (R 5 HSiO) m SiR 5 3 , where each R 5 is as defined above and
subscript k has an average value ranging from 0 to 12,
subscript m has an average value ranging from 4 to 12, and
a sum (k +m) has a value ranging from 4 to 13; and

viii) a combination of polyorganohydrogensiloxanes having formula (V) and formula (VI).

6. The process of claim 1 , where the curable groups on ingredient c) are selected from acrylate, alkoxy, epoxy, methacrylate, and combinations thereof.

7. The process of claim 1 , where ingredient c) comprises two or more reactive species, and the two or more reactive species have two or more different curable groups.

8. The process of claim 1 , where ingredient c) comprises compounds selected from:
(i) two or more silanes of formula (VII), where formula (VII) is R 6 n SiR 7 ( 4-n ); where
each subscript n independently has a value ranging from 1 to 3,
each R 6 is independently an alkenyl group or an alkynyl group, and
each R 7 is independently selected from an acrylate group, an alkoxy group, an epoxy group,
and a methacrylate group;

with the proviso that at least one R 7 group on one silane differs from at least one other R 7 group on another silane;
(ii) a silane of formula (VIII), where formula (VIII) is R 8 o SiR 9 (4-o) ; where
subscript o is has a value ranging from 1 to 3,
each R 8 is independently an alkenyl group or an alkynyl group, and
each R 9 is independently selected from an acrylate group, an alkoxy group, an epoxy group,
and a methacrylate group; and

(iii) an organic compound having an average, per molecule, of
1 to 2 alkenyl or alkynyl groups, and one or more reactive groups selected from an acrylate group, an alkoxy group, an epoxy group, and a methacrylate group.

9. The process of claim 3 , wherein the mixing the filler, a filler treating agent, and all or a portion of ingredient a) before step 1 ) forms a masterbatch that is a combination of a treated filler in the polyorganosiloxane of ingredient a).

10. The process of claim 1 , where the curable groups on ingredient c) are selected from isocyanate and urethane.

Assignees

• Dent Stanton
• Su Kai
• Tonge Lauren
• Tonge James
• Dow Corning

Inventors

• Dent Stanton
• Su Kai
• Tonge Lauren
• Tonge James

Classifications

• C08L83/14

  in which at least two but not all the silicon atoms are connected by linkages other than oxygen atoms (C08L83/10 takes precedence) · CPC title

• C08G77/50 Primary

  by carbon linkages · CPC title