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CN-122003456-A - Silicone elastomer composition

CN122003456ACN 122003456 ACN122003456 ACN 122003456ACN-122003456-A

Abstract

The present disclosure relates to curable silicone elastomer compositions that cure by hydrosilylation and that include an organopolysiloxane-based adhesion promoter that, when cured, provides the resulting silicone elastomer material with enhanced adhesion properties relative to thermoplastic materials, organic resin-based materials, or both thermoplastic and organic resin-based materials that are in direct contact with the thermoplastic materials, the organic resin-based materials, or both thermoplastic and organic resin-based materials prior to or during the curing process.

Inventors

  • P. Bayer
  • E. M. Santos
  • LIU NANGUO
  • ZHOU XIAOYUAN

Assignees

  • 美国陶氏有机硅公司

Dates

Publication Date
20260508
Application Date
20241022
Priority Date
20231023

Claims (15)

  1. 1. A curable silicone elastomer composition capable of achieving adhesion to a plastic/thermoplastic/resin material substrate, comprising: (A) One or more organopolysiloxanes containing at least 2 alkenyl and/or alkynyl groups per molecule and having a viscosity in the range of 1000mpa.s to 750,000mpa.s at 25 ℃; (B) A hydrosilylation curing catalyst package comprising a base and a catalyst, the hydrosilylation curing catalyst package comprises: (i) An organosilicon compound having at least 2, alternatively at least 3 Si-H groups per molecule, and (Ii) A hydrosilylation catalyst; (C) One or more reinforcing fillers, one or more non-reinforcing fillers, or mixtures thereof, and (D) An organosiloxane adhesion promoter having the structure: wherein each subscript n independently has an average value of from 2 to 18, Each R 1 is an independently selected monovalent hydrocarbon group (alternatively alkyl group), and Each R 2 is independently selected from the group consisting of hydrogen (H), an organic moiety comprising an epoxy group, and an organic moiety comprising an anhydride group; Provided that each R 2 in each molecule is H, or A mixture containing R 2 groups per molecule, said R 2 groups consisting of one or more organic moieties containing epoxy groups and one or more hydrogen (H) groups, or Each molecule contains a mixture of R 2 groups, the R 2 groups consisting of one or more organic moieties comprising anhydride groups and one or more hydrogens (H).
  2. 2. The curable silicone elastomer composition of claim 1, wherein R 2 comprises at least one organic moiety comprising an alkyl epoxy group or an alkyl glycidyl ether of the structure: and branched isomers thereof, wherein each subscript t can be the same or different and is from 2 to 30.
  3. 3. The curable silicone elastomer composition of claim 1, wherein R 2 comprises at least one organic moiety comprising an anhydride group, the organic moiety containing a group having the structure-C (=o) -O-C (=o) -, which can be cyclic.
  4. 4. The curable silicone elastomer composition of claim 3, wherein R 2 comprises at least one organic moiety comprising an anhydride group, the organic moiety comprising a maleic anhydride group of the structure: and branched isomers thereof, wherein each subscript t can be the same or different and is from 2 to 30.
  5. 5. The curable silicone elastomer composition of any claim, wherein each subscript n in component D is an average of from 2 to 6.
  6. 6. The curable silicone elastomer composition of any claim, wherein each subscript n in component D is an average value of from 2 to 4.
  7. 7. The curable silicone elastomer composition of any preceding claim, wherein component (D) is added to the composition in an amount of 0.5% to 5% by weight of the total composition of other components.
  8. 8. The curable silicone elastomer composition of any preceding claim, stored in at least two separate portions prior to use.
  9. 9. A method for preparing an article or a composite part of an article, the method comprising: a) Forming a mixture of curable silicone elastomer compositions according to any preceding claim, and B) Applying the mixture to a surface of a thermoplastic substrate, an organic resin substrate, or a thermoplastic and organic resin substrate; c) The mixture is cured at a temperature of 80 ℃ to 200 ℃.
  10. 10. The method of claim 9, wherein the substrate is an optional glass fiber reinforced polyamide or an optional glass fiber reinforced polyester.
  11. 11. An article comprising a silicone elastomer material cured from the curable silicone elastomer composition of any one of claims 1 to 8.
  12. 12. The article of claim 11, which is a composite part containing a silicone elastomer cured from the curable silicone elastomer composition of claims 1 to 8 adhered to a thermoplastic substrate, an organic resin substrate, or a thermoplastic and organic resin substrate.
  13. 13. The article of claim 11 or 12, which is a composite part containing a silicone elastomer cured from the curable silicone elastomer composition of claims 1 to 8, the silicone elastomer adhering to an optional glass fiber reinforced polyamide or an optional glass fiber reinforced polyester.
  14. 14. Use of a curable silicone elastomer composition according to claims 1to 8 in the preparation of an article comprising a cured elastomeric material made from the composition, the cured elastomeric material adhering to a thermoplastic substrate, an organic resin substrate or a thermoplastic and an organic resin substrate.
  15. 15. Use of the composition of claim 14 in the preparation of an article comprising a cured elastomeric material made from the composition adhered to an optional glass fiber reinforced polyamide or an optional glass fiber reinforced polyester.

Description

Silicone elastomer composition The present disclosure relates to curable silicone elastomer compositions comprising organopolysiloxane-based adhesion promoters that, when cured, provide the resulting silicone elastomer material with enhanced adhesion properties relative to a wide variety of substrates. The curable silicone elastomer composition cures via several curing mechanisms to provide a silicone elastomer material (silicone rubber), in particular by an addition (hydrosilylation) curing mechanism or a peroxide radical curing mechanism using a platinum group catalyst. The curable silicone elastomer composition may be capable of adhering to a substrate made of thermoplastic material, organic resin-based material, or both thermoplastic material and organic resin-based material during curing, which is placed in direct contact with the substrate prior to or during the curing process. In some cases, the curable silicone elastomer composition may be considered to have what is referred to in the industry as "selective adhesion" to certain substrates. For the avoidance of doubt, the term "selectively adhered" herein is intended to mean that the curable silicone elastomer composition, when cured, is capable of providing an adhesive bond directly to a thermoplastic or resin substrate without the need for prior application of, for example, a primer or the like to the substrate surface while being non-tacky or tacky to a metal substrate such as a mold. "selectively adhering" is sometimes also referred to as "self-adhering" or "self-bonding". The term "direct contact" is intended to mean that the adhesion properties of the curable silicone elastomer composition are such that there is no need to apply a primer to the surface of a substrate made of thermoplastic material, organic resin-based material or both thermoplastic material and organic resin-based material in order to create adhesion. When the silicone elastomer has cured on the substrate surface, there is adhesion between the interface of the silicone elastomer and the organic substrate. Liquid Silicone Rubber (LSR) elastomers are used in a wide variety of applications, including for example in consumer applications such as kitchen supplies, electrical and electronic, healthcare and automotive applications, especially because of their highly reliable properties with respect to heat resistance, weather resistance and electrical insulation. Selectively adhering LSR elastomers are used in many of these applications to produce hard-soft (plastic-LSR) composites in an injection molding process. For example, in automotive connector sealing applications, selectively adhering (sometimes also referred to as self-adhering) silicone elastomers can provide reliable sealing performance, particularly in harsh environments, as compared to many plastics. They provide a reliable seal for safe operation of automotive electronic control systems, thereby enhancing the safety and comfort experience for the driver and passengers. Silicone seals are also important for the waterproofing and sealing of components made of silicone elastomers in smart phones and wearable devices. However, in some applications, their use is limited because they do not form a sufficiently strong adhesive bond with plastic and thermoplastic substrates. Silicone elastomer compositions are also used in textile coatings, such as those used in apparel, automotive airbag coatings, and parachutes, where adhesion to the substrate is critical to improve performance. The selectively adhered silicone elastomers are also useful as adhesives, gaskets, seals, and coatings for a variety of advanced assembly applications, such as lid seals for electronic modules, encapsulants, potting gels and coatings for consumer and automotive electronics, cured in place gaskets, headlamps, and appliances. In addition, silicone elastomers having selective adhesion to thermoplastic film substrates can also be used as release substrates and release coatings. For example, it may be desirable to over-mold, coat, print, dispense, or otherwise apply the curable silicone elastomer composition to other components (or substrates) made of different or the same materials. In many cases, these substrates include thermoplastics based on organic polymers, such as polyesters, polyamides, polyimides, acrylics, styrenes, polyphthalamides, and polycarbonates. In other cases, the substrate comprises a thermosetting resin such as an epoxy or urethane or urea based polymer or composite such as an FR-4 substrate (FR-4 is a composite of woven fiberglass cloth with a flame retardant epoxy binder). For example, silicone gaskets can be molded onto thermoplastic shells made of polyamide or polyester. As another example, the wearable electronic device can be obtained by over-molding a hard thermoplastic with a soft layer or component made of liquid silicone rubber. Other examples include airbag fabrics such as polyamides or polyesters coated with silicone elasto