Silicone composition and process useful for improving the crease resistance and abrasion resistance of airbags, intended for protecting a vehicle occupant

Patent metadata

Field	Value
Publication number	US-10676574-B2
Application number	US-201615762603-A
Country	US
Kind code	B2
Filing date	Sep 22, 2016
Priority date	Sep 25, 2015
Publication date	Jun 9, 2020
Grant date	Jun 9, 2020

Abstract

The general field of the invention is that of silicone coating compositions, in particular those of two-component or multi-component type, that can be crosslinked by polyaddition or hydrosilylation reactions to produce a support coated by a silicone elastomer as a thin layer. These silicone compositions, when they are crosslinked, are suitable, inter alia, as coatings, for example for the protection or mechanical reinforcement of various textile substrates such as for example fibrous, woven, knitted or nonwoven supports. The targeted objective is to provide a silicone elastomer coating composition that can be crosslinked by polyaddition reactions and that is useful in particular for applications in the field of inflatable safety bags for vehicles, or airbags, having, after crosslinking, optimum properties in terms of adhesion, thinness, lightness and crease and abrasion resistance, but also good mechanical properties. This silicone coating composition should also be easy to use and to apply.

First claim

The invention claimed is:

1. A silicone composition A comprising a silicone base B capable of crosslinking or curing by polyaddition and comprising an adhesion promoter system D comprising at least one organic titanium compound M and at least one additive X which is a linear organopolysiloxane comprising siloxyl units (I.1) to (I.3) having the formulae below:

Y
a

⁢

Z
b
1

⁢
Si
⁢

⁢

O

4
-

(

a
+
b

)

2

(

I
⁢
.1

)

Z
3
2

⁢
Si
⁢

⁢

O

1
2

(

I
⁢
.2

)

H
d

⁢

Z
e
3

⁢
Si
⁢

⁢

O

4
-

(

d
+
e

)

2

(

I
⁢
.3

)

and not comprising units of formula (I.4):

Z
2
2

⁢

SiO

2
2

(

I
⁢
.4

)

wherein
a=1 and b=1 or 2
d=1 and e=1 or 2
Y represents a radical comprising a hydrocarbon-based group having from 2 to 20 carbon atoms and an epoxy function, with optionally one or more heteroatoms,
Z 1 , Z 2 and Z 3 , which may be identical or different, represent a monovalent hydrocarbon-based group having from 1 to 30 carbon atoms,

with the condition according to which the additive X comprises, per molecule, at least two siloxyl units (I.1) bearing epoxyfunctional hydrocarbon-based groups and at least three siloxyl units (I.3) bearing hydrosiloxyl groups.

2. The silicone composition A as claimed in claim 1 , wherein the additive X has a total number of siloxyl units of between 7 and 30.

3. The silicone composition A as claimed in claim 1 , wherein the additive X does not contain alkoxy, vinyl, hydroxyl or methacryloxy functional groups.

4. The silicone composition A as claimed in claim 1 , wherein the additive X has a molar ratio between the siloxyl units (I.1) and the siloxyl units (I.3) of between 0.5 and 4.

5. The silicone composition A as claimed in claim 1 , wherein the adhesion promoter system D also comprises an organosilane G comprising at least one epoxy radical.

6. The silicone composition A as claimed in claim 1 , wherein the concentration of epoxy units is between 10 and 60 mmol per 100 g of composition A.

7. The silicone composition A as claimed in claim 1 , wherein the silicone base B comprises
at least one organopolysiloxane E having, per molecule, at least two C 2 -C 12 alkenyl groups each bonded to a different silicon atom,
at least one organopolysiloxane resin F comprising from 0.1% to 20% by weight of C2-C6 alkenyl groups each bonded to a different silicon atom,
optionally at least one organohydropolysiloxane H having, per molecule, at least two hydrogen atoms each bonded to a different silicon atom,
an effective amount of a polyaddition catalyst C which is a metal or metal compound of the platinum group,
at least one inhibitor I, and
optionally at least one filler J.

8. A two-component precursor system for the composition A as claimed in claim 7 which is in two distinct parts A1 and A2 intended to be mixed so as to form the composition A, wherein one of said parts contains the catalyst C while the other part contains the additive X and the organohydropolysiloxane H.

9. A silicone elastomer that can be obtained by crosslinking and/or curing the silicone composition A as defined in claim 1 .

10. A process for preparing a fibrous support coated with a silicone elastomer, comprising:
a) preparing the silicone composition A as claimed in claim 1 ,
b) applying onto one or two faces of a fibrous support at least 10 g/m 2 of the silicone composition A prepared in a), and
c) crosslinking the deposit formed in b) so as to form an elastomer by heating at a temperature that can reach 210° C., optionally through action of electromagnetic radiation or hot air.

11. The process as claimed in claim 10 , wherein the fibrous support is made of polyamide or of polyester.

Assignees

• Bluestar Silicones France
• Elkem Silicones France Sas

Inventors

• BORECKI Karine
• Seggio Anne
• Djian Damien
• Bordes Bertrand

Classifications

• C08G77/20

  containing silicon bound to unsaturated aliphatic groups · CPC title

• D06N2211/268

  Airbags · CPC title

• D06M15/65

  containing epoxy groups · CPC title

• B60R21/235 Primary

  characterised by their material · CPC title

• C08L83/00

  Compositions of macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon only; Compositions of derivatives of such polymers · CPC title