Silicone elastomer composition

Abstract

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

Description

[0001] This disclosure relates to curable silicone elastomer compositions comprising an organopolysiloxane adhesion promoter that, upon curing, provides the resulting silicone elastomer material with enhanced adhesion properties relative to a wide variety of substrates.

[0002] Curable silicone elastomer compositions are cured via several curing mechanisms to provide silicone elastomer materials (silicone rubber), particularly via addition (hydrogenation silanization) curing mechanisms utilizing platinum group catalysts or peroxide radical curing mechanisms.

[0003] Curable silicone elastomer compositions are capable of adhering during curing to substrates made of thermoplastic materials, organic resin-based materials, or both thermoplastic and organic resin-based materials, which are placed in direct contact with the substrate before or during the curing process. In some cases, the curable silicone elastomer compositions may be considered to have what is known in the industry as "selective adhesion" to certain substrates.

[0004] For the avoidance of ambiguity, the term "selective adhesion" herein is intended to mean that, upon curing, the curable silicone elastomer composition provides an adhesive bond directly to thermoplastic or resin substrates without prior application of, for example, a primer to the substrate surface, while being non-adhesive or adhesive to metal substrates (such as molds). "Selective adhesion" is sometimes also referred to as "self-adhesive" or "self-bonding."

[0005] The term "direct contact" is intended to mean that the adhesive properties of the curable silicone elastomer composition eliminate the need for a primer to be applied to the surface of a substrate made of thermoplastic, organic resin-based, or a combination of thermoplastic and organic resin-based materials to achieve adhesion. Adhesion exists at the interface between the silicone elastomer and the organic substrate once the silicone elastomer has already cured on the substrate surface.

[0006] Liquid silicone rubber (LSR) elastomers are used in a wide variety of applications, including, for example, consumer applications such as kitchenware; electrical and electronic, healthcare and automotive applications, especially because of their highly reliable properties in terms of heat resistance, weather resistance and electrical insulation.

[0007] Selective adhesion LSR elastomers are used in many of these applications to produce hard-soft (plastic-LSR) composites in injection molding processes.

[0008] For example, in automotive connector sealing applications, selectively adhesive (sometimes called self-adhesive) silicone elastomers offer reliable sealing performance compared to many plastics, especially in harsh environments. They provide reliable seals for the safe operation of automotive electronic control systems, thereby enhancing the safety and comfort experience for drivers and passengers. Silicone seals are also important for waterproofing and sealing components made of silicone elastomers in smartphones and wearable devices. However, their use is limited in some applications because they cannot form sufficiently strong adhesive bonds to plastic and thermoplastic substrates. Silicone elastomer compositions are also used in fabric coatings, such as those used in clothing, automotive airbag coatings, and parachutes, where adhesion to the substrate is critical for improved performance. Selectively adhesive silicone elastomers are also used as adhesives, gaskets, seals, and coatings for a variety of advanced assembly applications, such as cover seals for electronic modules, encapsulants, potting gels and coatings for consumer and automotive electronics, in-situ curing gaskets, headlights, and appliances. Additionally, silicone elastomers with selective adhesion to thermoplastic film substrates can also be used as release substrates and release coatings.

[0009] For example, it is desirable to overmold, coat, print, dispense, or otherwise apply curable silicone elastomer compositions to other parts (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, styrene-based materials, polyphthalamides, and polycarbonates. In other cases, the substrates include thermosetting resins such as polymers or composites based on epoxy groups or urethanes or ureas, such as FR-4 substrates (FR-4 is a composite of woven fiberglass cloth with a flame-retardant epoxy resin binder). For example, silicone gaskets can be molded onto thermoplastic housings made of polyamides or polyesters. Wearable electronic devices, for instance, can be obtained by overmolding rigid thermoplastics using a soft layer or component made of liquid silicone rubber. Other examples include airbag fabrics coated with silicone elastomers, such as polyamides or polyesters. Organic substrates to which selective adhesion silicone rubber compositions can be cured include, for example, acrylonitrile-butadiene-styrene, polyphenylene / styrene blends, polystyrene, polycarbonate (PC), polyurethane, styrene resin, polyethylene, polypropylene, acrylics, polyacrylates, polymethacrylates, polyacrylamide, polyesters such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT); polyphenylene ether, polyphenylene sulfide, polysulfone, polyamide (PA) such as nylon 6 (PA 6) Nylon 6,6 (PA6,6) and Nylon 6,10; blends of polyamide resins with syndiotactic polystyrene, polyimide, fluoropolymers and liquid crystal resins, resin-free polyetherimide; phenolic resins, epoxy resins, epoxy molding compounds, urea resins, melamine resins, alkyd resins, acrylonitrile-butadiene-styrene, styrene-modified poly(phenylene ether), poly(phenylene sulfide), vinyl esters or polyphthalamides, and combinations thereof, while achieving good separation from metal molds during injection molding.

[0010] In other embodiments, the curable silicone composition may be applied to inorganic substrates such as metals or glass ceramics, to cellulose substrates such as paper or wood, and to the previously mentioned organic substrates described above, or any combination thereof, as a composite presented in a single substrate, or applied in any combination between multiple substrates to form an adhesive article. However, in some cases, such as bonding with polyamide or polyester fabrics, even selectively adhesive silicone compositions often require the fabric to be plasma- or corona-treated to exhibit good adhesion and scrub resistance.

[0011] Initially, applying a primer to the substrate surface was used to overcome the poor adhesion of such elastomers to a wide range of substrates. However, the use of a primer-required method introduced several problems. Primer methods are troublesome, not only because they can lead to unreliable productivity, quality control issues, and practical reliability problems in the manufactured parts / articles, but also because the selection, storage, use, and processing of the primer can significantly affect the level of adhesion, necessitating special care during storage before use. Therefore, the use of primer needs to be carefully controlled to achieve good adhesion, and such methods are often time-consuming and can result in low productivity and inconsistent seal quality. Therefore, it is desirable to avoid the use of primer whenever possible, and this has since been achieved through the use of selectively adhesive silicone elastomer materials with satisfactory adhesion but without the need for primer application.

[0012] Similarly, high-energy surface pretreatments (such as irradiation by exposure to plasma, corona, flame, UV, or UV-ozone sources) to activate surfaces for adhesion can be problematic. While high-energy treatments eliminate the need for curing wet chemical primers, they typically require specialized capital equipment and assembly processes to safely perform the pretreatment.

[0013] In the case of addition (hydrosilanization) curing compositions, it has been suggested to incorporate a hydrosilanized curable silicone elastomer crosslinking agent, such as an organohydrosiloxane, into the plastic or thermoplastic substrate. However, such methods have been found to have a negative effect on the physical properties of the thermoplastic itself, thereby inhibiting the resin from exhibiting its own properties.

[0014] Physical bonding methods that do not require adhesion can also be used, but leaving the two segments exposed may result in them detaching from the bond due to physical forces. Using selectively adhesive silicone elastomers is a preferred alternative because it can at least in part impart better productivity, quality control, and reliability to the parts / products by eliminating the need for primer or surface pretreatment.

[0015] Several chemical approaches have been proposed for adhesion promotion in selective adhesion cases. The use of alkoxysilanes (e.g., alkoxysilanes containing glycidoxy and acryloyloxy groups) is effective but not preferred because they tend to negatively impact storage stability, for example, due to increased viscosity, loss of adhesion, and inherent reactivity to moisture and hydrolytic instability during storage. They may also have the additional disadvantage of being reactive to metal surfaces, thus posing a challenge to the injection molding processes where they are most commonly used. Adhesion promoters containing phenylene / bisphenol A structural units are well-known and tend to be designed for adhesion to plastics containing aromatic counterparts (e.g., polybutylene terephthalate (PBT)); however, lack of compatibility and shelf life are drawbacks, and they may not be suitable for sensitive medical / consumer applications.

[0016] Mixtures / reaction products of standard adhesion promoters and other components (e.g., co-crosslinking agents and condensation catalysts) were also used, but had several drawbacks, including discoloration problems, formulation complexity (i.e., difficulty in formulating storage-stable two-part systems due to the inherent reactive interactions of various adhesion components), and the fact that platinum group hydrosilanization catalysts and crosslinking agents that can be added to cure compositions generally result in good adhesion but poor shelf life and are too expensive for many applications.

[0017] The durability of selective adhesion of silicone elastomer materials to thermoplastic substrates, organic resin substrates, or both thermoplastic and organic resin substrates is crucial for the successful use of such combinations, but providing composites with good adhesion to untreated thermoplastics remains a technical challenge.

[0018] This disclosure relates to a curable silicone elastomer composition capable of adhesion to plastic / thermoplastic / resin material substrates, and comprising:

[0019] (A) One or more organopolysiloxanes containing at least two alkenyl and / or alkynyl groups per molecule and having a viscosity in the range of 1,000 mPa·s to 750,000 mPa·s at 25°C;

[0020] (B) A hydrogenated silanization curing catalyst package, the hydrogenated silanization curing catalyst package comprising:

[0021] (i) organosilicon compounds having at least two, alternatively at least three, Si-H groups per molecule; and

[0022] (ii) Hydrosilylation catalyst;

[0023] (C) One or more reinforcing fillers, one or more non-reinforcing fillers, or a mixture thereof; and

[0024] (D) Organosiloxane adhesion promoters having the following structure:

[0025]

[0026] Each subscript n independently has an average value between 2 and 18.

[0027] Each R 1 It is an independently selected monovalent hydrocarbon group, with an alternatively selected alkyl group, and...

[0028] Each R 2 The group consisting of hydrogen (H), an organic moiety containing an epoxy group, and an organic moiety containing an anhydride group is selected independently.

[0029] The prerequisite is that each R in each molecule 2 It's H, or

[0030] Each molecule contains R 2 A mixture of groups, the R 2 The group consists of one or more organic moieties containing an epoxy group and one or more hydrogen atoms (H); or

[0031] Each molecule contains R 2 A mixture of groups, the R 2 The group consists of one or more organic moieties containing an anhydride group and one or more hydrogen atoms (H).

[0032] Therefore, R per molecule 2 At least one of the groups is hydrogen, thus providing one or more Si-H groups for each molecule. Surprisingly, the addition of the component (D) containing diphenylsiloxane groups found in this paper provides adhesion of the silicone elastomer to engineering plastics such as polyester or nylon, wherein each R... 2 It is H. Furthermore, R is replaced by an organic moiety containing an epoxide group or anhydride group. 2 Some R in hydrogen 2 Hydrogen further enhances adhesion properties.

[0033] A method for preparing an article or a composite component of an article is provided, the method comprising:

[0034] a) A mixture forming a curable silicone elastomer composition according to any of the preceding claims, and

[0035] b) Apply the mixture to the surface of a thermoplastic substrate, an organic resin substrate, or a combination of thermoplastic and organic resin substrates;

[0036] c) Curing the mixture at temperatures between 80°C and 200°C.

[0037] An article is also provided comprising a silicone elastomer material cured by the curable silicone elastomer composition described herein.

[0038] Furthermore, the use of the curable silicone elastomer composition described herein in the preparation of articles comprising a cured elastomer material made from the composition, the cured elastomer material being adhered to a thermoplastic substrate, an organic resin substrate, or a thermoplastic and organic resin substrate.

[0039] The different components of the compositions described herein are discussed below.

[0040] Component (A)

[0041] Component (A) of the curable silicone elastomer composition comprises one or more organopolysiloxanes having at least two alkenyl groups, at least two alkynyl groups, or mixtures thereof per molecule and having a viscosity in the range of 1000 mPa·s to 750,000 mPa·s at 25°C. The organopolysiloxane (A) may be a single polymer or a combination of two or more different polymers.

[0042] Each organopolysiloxane polymer of component (A) contains a plurality of silanoxy units of formula (I):

[0043]

[0044] The subscript "a" can be 0, 1, 2 or 3.

[0045] When R' is a monovalent hydrocarbon group, the silanoxy unit can be described by shorthand (abbreviation) nomenclature, namely -"M", "D", "T", and "Q". The M unit corresponds to the silanoxy unit where a = 3, i.e., R'3SiO 1 / 2 The D unit corresponds to the silanoxy unit where a = 2, i.e., R'2SiO 2 / 2 The T unit corresponds to the silanoxy unit where a = 1, i.e., R'1SiO. 3 / 2 The Q unit corresponds to the silanoxy unit where a = 0, i.e., SiO. 4 / 2 The organopolysiloxane polymer of component (A) is essentially linear, but may contain a certain proportion of branches due to the presence of T units within the molecule (as previously described), thus the average value of a in structure (I) is about 2.

[0046] The unsaturated group of component (A) may be located at the end or side chain of the organopolysiloxane polymer, or at both positions. The unsaturated group of component (A) may be an alkenyl group or an alkynyl group as described above, but preferably an alkenyl group. When present, each alkenyl group may comprise, for example, 2 to 30, alternatively 2 to 24, alternatively 2 to 20, alternatively 2 to 12, alternatively 2 to 10, alternatively 2 to 6 carbon atoms. When present, the alkenyl group may be, but is not limited to, those exemplified below: vinyl, allyl, methyl allyl, propenyl, hexenyl, and cyclohexenyl groups. When present, each alkynyl group may also have 2 to 30, alternatively 2 to 24, alternatively 2 to 20, alternatively 2 to 12, alternatively 2 to 10, alternatively 2 to 6 carbon atoms. Examples of alkynyl groups may be exemplified by, but are not limited to, the following: ethynyl, propynyl, and butynyl groups. Preferred examples of unsaturated groups in component (A) include vinyl, propenyl, isopropenyl, butenyl, allyl, and 5-hexenyl.

[0047] In formula (I), in addition to the unsaturated groups described above, each R' is a monovalent hydrocarbon group, independently selected from aliphatic hydrocarbon groups, substituted aliphatic hydrocarbon groups, aromatic groups, or substituted aromatic groups. Each aliphatic hydrocarbon group may be exemplified by, but is not limited to, alkyl groups having 1 to 20 carbons / group, alternatively 1 to 15 carbons / group, alternatively 1 to 12 carbons / group, alternatively 1 to 10 carbons / group, alternatively 1 to 6 carbons / group, or cycloalkyl groups, such as cyclohexyl. Specific examples of alkyl groups having 1 to 20 carbons may include methyl, ethyl, propyl, pentyl, octyl, undecyl, and octadecyl groups, alternatively methyl and ethyl groups.

[0048] For the purposes of this application, "substituted" means that one or more hydrogen atoms in a hydrocarbon group are replaced by another substituent. Examples of such substituents include, but are not limited to, halogen atoms such as chlorine, fluorine, bromine, and iodine; groups containing halogen atoms such as chloromethyl, perfluorobutyl, trifluoroethyl, trifluoropropyl, and nonafluorohexyl; oxygen atoms; groups containing oxygen atoms such as (meth)acrylic acid and carboxyl; nitrogen atoms; groups containing nitrogen atoms such as amino, amide, and cyano functional groups; sulfur atoms; and groups containing sulfur atoms such as mercapto groups. The substituted aliphatic hydrocarbon group is preferably a non-halogenated alkyl group. Aliphatic non-halogenated organic groups are exemplified by, but are not limited to, the above-mentioned alkyl groups having substituted groups, such as suitable nitrogen-containing groups, such as amide groups, imino groups; oxygen-containing groups (such as polyoxyethylene groups, carbonyl groups, alkoxy groups, and hydroxyl groups). Additional organic groups may include sulfur-containing groups, phosphorus-containing groups, and boron-containing groups. Examples of aromatic groups or substituted aromatic groups are phenyl groups and substituted phenyl groups having substituted groups as described above.

[0049] Component (A) of the curable silicone elastomer composition may, for example, be selected from polydimethylsiloxane, alkylmethyl polysiloxane, alkylaryl polysiloxane, or copolymers thereof (wherein alkyl refers to any suitable alkyl group, alternatively having two or more carbon atoms), provided that each polymer has a viscosity of the organopolysiloxane polymer (a) that is between 1000 mPa·s and 750,000 mPa·s, including the end values, at 25°C.

[0050] Therefore, for example, component (A) could be:

[0051] Dialkylene-terminated polydimethylsiloxanes, such as dimethylvinyl-terminated polydimethylsiloxanes; dialkylene-terminated dimethylmethylphenylsiloxanes, such as dimethylvinyl-terminated dimethylmethylphenylsiloxanes; trialkyl-terminated dimethylmethylvinyl polysiloxanes; dialkylvinyl-terminated dimethylmethylvinyl polysiloxane copolymers; dialkylvinyl-terminated methylphenyl polysiloxanes, dialkylene-terminated methylvinylmethylphenylsiloxanes; dialkylene-terminated methylvinyldiphenylsiloxanes; dialkylene-terminated methylvinylmethylphenyldimethylsiloxanes; trimethyl-terminated methylvinylmethylphenylsiloxanes; trimethyl-terminated methylvinylmethylphenylsiloxanes; or trimethyl-terminated methylvinylmethylphenyldimethylsiloxanes.

[0052] The viscosity of the organopolysiloxane polymer (A) is from 1000 mPa·s to 750,000 mPa·s, including the end value, at 25°C; alternatively, from 1000 mPa·s to 650,000 mPa·s, from 1000 mPa·s to 500,000 mPa·s, from 1000 mPa·s to 300,000 mPa·s, from 1000 mPa·s to 250,000 mPa·s, from 1000 mPa·s to 150,000 mPa·s, and from 1000 mPa·s to 100,000 mPa·s at 25°C.

[0053] Unless otherwise specified, all viscosity measurements given are performed using Brookfield. ™ The RVF viscometer is provided, where the rotor is selected based on the viscosity range and operated at a preferred rpm. An alternative is the cup / rotor method using ASTM D 1084 Method B, derived from Brookfield. ™ Rotors with RV or LV ranges that are most suitable for the viscosity range.

[0054] Typically, for each organopolysiloxane polymer containing at least two silicon-bonded alkenyl groups per molecule of component (A), the alkenyl and / or alkynyl content (e.g., vinyl content) of the polymer is from 0.01 wt% to 3 wt%, alternatively, the organopolysiloxane or component (A) of each organopolysiloxane containing at least two unsaturated groups per molecule is from 0.01 wt% to 2.5 wt%, alternatively, component (A) is from 0.001 wt% to 2.0 wt%, and 0.01 wt% to 1.5 wt%, wherein the unsaturated groups are selected from alkenyl or alkynyl groups per molecule of component (A). The alkenyl / alkynyl content of component (A) is determined using quantitative infrared analysis in accordance with ASTM E168-16 (2023).

[0055] The organopolysiloxane (A) is present in the curable silicone elastomer composition in an amount of 10% to 85% by weight (wt.%) of the composition, alternatively 20% to 80% by weight, alternatively 20% to 75% by weight, alternatively 25% to 75% by weight, alternatively 30% to 75% by weight, and alternatively 30% to 60% by weight. Typically, component (A) is present in the amount of the difference between 100% by weight of the composition and the cumulative weight percentage of other components / ingredients.

[0056] Hydrogenated silane curing catalyst package (B)

[0057] The hydrogenation silanization curing catalyst package (B) for the curable silicone elastomer composition comprises:

[0058] (i) organosilicon compounds having at least two, alternatively at least three, Si-H groups per molecule; and

[0059] (ii) Hydrosilylation catalyst.

[0060] Component (B)(i)

[0061] Component (B)(i) is an organosilicon compound that acts as a crosslinking agent. Component (B)(i) is an organosilicon compound containing at least two or three silicon-bonded hydrogen atoms per molecule. Component (B)(i) typically contains three or more silicon-bonded hydrogen atoms, thus allowing the hydrogen atoms to react with the unsaturated alkenyl or alkynyl groups of polymer (A) to form a network structure and thereby cure the composition. When polymer (A) molecules have more than (>) two alkenyl or alkynyl groups, some or all of component (B)(i) may optionally have two silicon-bonded hydrogen atoms per molecule.

[0062] Organosilicon compounds can have linear, branched, cyclic, or resinous structures. Cyclosilanes and cyclosiloxanes can have 3 to 12 silicon atoms, alternatively 3 to 10 silicon atoms, or alternatively 3 to 4 silicon atoms. In acyclic polysilanes and polysiloxanes, the silicon-bonded hydrogen atoms can be located at the terminal, side, or both positions.

[0063] Examples of suitable organosilanes may include diphenylsilane, 2-chloroethylsilane, bis[(p-dimethsilyl)phenyl]ether, 1,4-dimethyldisilazane, 1,3,5-tris(dimethsilyl)benzene, 1,3,5-trimethyl-1,3,5-trisilane, poly(methylmethylene)phenylene, and poly(methylmethylene)methylene. In some examples, organohydrosilanes may have the formula HR. 5 2Si-R 6 -SiR 5 2H, where R 5 All of them are C1 to C1 unsaturated. 10 Hydrocarbon group or C1 to C 10 Halogen-substituted hydrocarbon groups, and R 6 It is a non-aliphatic unsaturated alkylene group, having a Ph(C) group selected from 1,4-disubstituted phenyl or 1,3-disubstituted phenyl, 4,4'-disubstituted -1,1'-biphenyl or 3,3'-disubstituted -1,1'-biphenyl or para-disubstituted or meta-disubstituted Ph(C) groups. g H 2g Ph's formula.

[0064] The molecular configuration of organopolysiloxanes containing at least two or three silicon-bonded hydrogen atoms per molecule (B) is not specifically limited, and they can be linear, linear with some branches, cyclic, or based on silicone resins. Given their very low viscosity, the viscosity of the crosslinking agent is determined by capillary measurement according to ASTM D-445.

[0065] The organic groups used for silicon bonding in component (B)(i) may be exemplified by the following groups: methyl, ethyl, propyl, butenyl, pentenyl, hexyl or similar alkyl groups; phenyl, tolyl, xylyl or similar aryl groups; 3-chloropropyl, 3,3,3-trifluoropropyl or similar haloalkyl groups, wherein methyl and phenyl groups are preferred.

[0066] Organopolysiloxanes containing at least two or three silicon-bonded hydrogen atoms per molecule (B)(i) are typically added in an amount such that the molar ratio of the total number of silicon-bonded hydrogen atoms in component (B)(i) to the total number of alkenyl and / or alkynyl groups in polymer (A) is between 0.5:1 and 20:1. When this ratio is less than 0.5:1, a well-cured composition is not obtained. When this ratio exceeds 20:1, there is a tendency for the cured composition to increase in hardness upon heating.

[0067] Examples of organopolysiloxanes containing at least 2 or 3 silicon-bonded hydrogen atoms per molecule (B)(i) include, but are not limited to:

[0068] (a') Trimethylsiloxy-terminated methylhydropolysiloxane,

[0069] (b') Trimethylsiloxy-terminated polydimethylsiloxane-methylhydrosiloxane,

[0070] (c') Dimethylsiloxane-methylhydrosiloxane copolymers with dimethylhydrosiloxane end-capped methylhydrosiloxanes.

[0071] (d') Dimethylsiloxane-methylhydrosiloxane cyclic copolymer,

[0072] (e') is derived from (CH3)2HSiO 1 / 2 Unit, (CH3)3SiO 1 / 2 unit and SiO 4 / 2 copolymers and / or silicone resins composed of units,

[0073] (f') is derived from (CH3)2HSiO 1 / 2 unit and SiO 4 / 2 copolymers and / or silicone resins composed of units,

[0074] (g') is derived from (CH3)2HSiO 1 / 2 Unit, SiO 4 / 2 Unit and (C6H5)3SiO1 / 2 Units, and copolymers and / or silicone resins comprising methyl groups replaced by phenyl or other alkyl groups.

[0075] Alternatively, component (B)(i) crosslinking agent may be a filler, such as silica treated with one of the aforementioned substances.

[0076] Component (B) (i) can be exemplified by the following compounds: methylhydrosiloxanes terminated at both ends of the molecule with trimethylsiloxy groups; copolymers of methylhydrosiloxanes and dimethylsiloxanes terminated at both ends of the molecule with trimethylsiloxy groups; dimethylsiloxanes terminated at both ends of the molecule with dimethylhydrosiloxy groups; copolymers of methylhydrosiloxanes and dimethylsiloxanes terminated at both ends of the molecule with dimethylhydrosiloxy groups; copolymers of methylhydrosiloxanes and methylphenylsiloxanes terminated at both ends of the molecule with dimethylphenylsiloxy groups; cyclic methylhydrosiloxanes; and compounds derived from (CH3)2HSiO 1 / 2 Siloxane units and SiO 4 / 2 A copolymer composed of units; consisting of (CH3)2HSiO 1 / 2 Siloxane unit, (CH3)3SiO 1 / 2 Siloxane units and SiO 4 / 2 The unit, the copolymer of the aforementioned organopolysiloxanes, wherein some or all of the methyl groups are replaced by ethyl, propyl or similar alkyl groups; phenyl, tolyl or similar aryl groups; 3,3,3,-trifluoropropyl or similar haloalkyl groups; or a mixture of two or more of the aforementioned organopolysiloxanes.

[0077] The organosilicon compound crosslinking agent (B)(i) is typically present in a certain amount in the curable silicone elastomer composition such that the ratio of the molar number of silicon-bonded hydrogen atoms in component (B)(i) to the molar number of unsaturated groups (e.g., alkenyl groups) in component (A) is in the range of (0.7:1.0) to (5.0:1.0), preferably (0.9:1.0) to (2.5:1.0), and most preferably (0.9:1.0) to (2.0:1.0).

[0078] The silicon-bonded hydrogen (Si-H) content of component (B)(i) is determined using quantitative infrared analysis in accordance with ASTM E168-16 (2023). In this case, when relying on a hydrogen silanization curing process, the ratio of silicon-bonded hydrogen to alkenyl (vinyl) and / or alkynyl groups is important. Generally, this is determined by calculating the total weight % of alkenyl groups (e.g., vinyl) [V] in the composition and the total weight % of silicon-bonded hydrogen [H] in the composition, and assuming a molecular weight of 1 for hydrogen and a molecular weight of 27 for vinyl, the molar ratio of silicon-bonded hydrogen to vinyl is 27[H] / [V].

[0079] Typically, depending on the number of unsaturated groups in component (A) and the number of Si-H groups in component (B)(i), component (B)(i) will be present in an amount of 0.1% to 40% by weight of the total composition, alternatively 0.5% to 20% by weight of the total composition, alternatively 0.5% to 10% by weight of the total composition, and also alternatively 1% to 5% by weight of the total composition.

[0080] Component (B)(ii)

[0081] Component (B)(ii) of the curable silicone elastomer composition is at least one hydrosilylation (addition) reaction catalyst. These hydrosilylation (addition) reaction catalysts are typically selected from catalysts of platinum group metals (platinum, ruthenium, osmium, rhodium, iridium, and palladium), or compounds of one or more of these metals. Platinum and rhodium compounds are preferred due to the high activity levels of these catalysts in the hydrosilylation reaction. Component (B)(ii) catalyzes the reaction between the alkenyl group (e.g., vinyl group) of component (A) and the Si-H group of component (B)(ii), thereby generating a crosslinked network when the curable silicone elastomer composition is cured into its corresponding elastomer.

[0082] Catalyst (B)(ii) may be a platinum group metal, a platinum group metal deposited on a support (such as activated carbon, metal oxides such as alumina or silica, silica gel or charcoal powder), or a compound or complex of a platinum group metal.

[0083] Examples of preferred hydrosilylation catalysts (B)(ii) include platinum-based catalysts such as platinum black, platinum oxide (Adams catalyst), platinum on various solid supports, chloroplatinic acid (e.g., hexachloroplatinic acid (Pt oxidation state IV) (Speier catalyst)), chloroplatinic acid in solution of alcohols (e.g., isooctanol or pentanol) (Lamoreaux catalyst), and complexes of chloroplatinic acid with olefinically unsaturated compounds (such as alkenes) and organosiloxanes containing olefinically unsaturated silicon-bonded hydrocarbon groups, such as tetravinyltetramethylcyclotetrasiloxane-platinum complex (Ashby catalyst). Soluble platinum compounds that can be used include, for example, platinum-olefin complexes of the formula (PtCl2.olefin)2 and H (PtCl3.olefin), preferably in this context olefins having 2 to 8 carbon atoms, such as isomers of ethylene, propylene, butene, and octene, or cycloalkanes having 5 to 7 carbon atoms, such as cyclopentene, cyclohexene, and cycloheptene. Other soluble platinum catalysts include, for example, platinum-cyclopropane complexes of formula (PtCl2C3H6)2, reaction products of hexachloroplatinic acid with alcohols, ethers, and aldehydes, or mixtures thereof, or reaction products of hexachloroplatinic acid and / or its conversion products with vinylsiloxanes (such as methylvinylcyclotetrasiloxane) in the presence of an ethanol solution containing sodium bicarbonate. Platinum catalysts with phosphorus and amine ligands, such as (Ph3P)2PtCl2, and platinum-vinylsiloxane complexes, such as symmetrical divinyltetramethyldisiloxane, can also be used.

[0084] Therefore, specific examples of suitable platinum-based catalysts include:

[0085] (i) A complex of chloroplatinic acid as described in US 3,419,593 with an organosiloxane containing an olefinic unsaturated hydrocarbon group;

[0086] (ii) Chloroplatinic acid in hexahydrate or anhydrous form;

[0087] (iii) A platinum-containing catalyst, which is obtained by a method comprising the steps of reacting chloroplatinic acid with an aliphatic unsaturated organosilicon compound (such as divinyltetramethyldisiloxane);

[0088] (iv) olefin-platinum-silyl complexes as described in U.S. Patent 6,605,734, such as (COD)Pt(SiMeCl2)2, wherein “COD” is 1,5-cyclooctadiene; and / or

[0089] (v) The Karstedt catalyst is a Pt2 (divinyltetramethyldisiloxane)3 complex, typically containing 30% to 50% by weight of platinum metal in the complex. It is typically introduced into silicone rubber compositions in the form of a premixed form with a vinylsiloxane polymer. This mixture consists of about 0.25% to 2.0% by weight of the catalyst complex in 99.75% to 98% by weight of a vinylsiloxane polymer, which typically has a viscosity of about 200 mPa·s to 750 mPa·s at 25°C using the test methods described for component (a).

[0090] Solvents such as toluene and similar organic solvents have historically been used as alternatives, but the use of vinylsiloxane polymers is currently the preferred choice. These are described in US3,715,334 and US3,814,730.

[0091] The hydrogen silylation catalyst (B)(ii) of the hydrogen silylation curable silicone elastomer composition is present in the total composition in a catalytic amount sufficient to catalyze the addition / hydrosilylation reaction and cure the composition into a silicone elastomer material under desired conditions. Different amounts of hydrogen silylation catalyst (B)(ii) can be used to tailor the reaction rate and curing kinetics. Based on the weight of the composition, the catalytic amount of hydrogen silylation catalyst (B)(ii) is typically between 0.01 ppm and 10,000 parts per million (ppm) of platinum group metals, alternatively between 0.01 ppm and 5,000 ppm; alternatively between 0.01 ppm and 3,000 ppm; and alternatively between 0.01 ppm and 1,000 ppm. In specific embodiments, the catalytic amount of the catalyst can be in the range of 0.01 ppm to 1,000 ppm, alternatively 0.01 ppm to 750 ppm, alternatively 0.01 ppm to 500 ppm, and alternatively 0.01 ppm to 100 ppm of metal, based on the weight of the composition.

[0092] This range may refer only to the metal content within the catalyst or to the entire catalyst (including its ligands) as detailed, but typically these ranges refer only to the metal content within the catalyst. The catalyst may be added as a single substance or as a mixture of two or more different substances. Typically, depending on the form / concentration of the catalyst package provided, the amount of catalyst present will range from 0.001% by weight to 3.0% by weight of the composition.

[0093] Component (C)

[0094] Component (C)a of the curable silicone elastomer composition is one or more reinforcing fillers, one or more non-reinforcing fillers, or a mixture thereof.

[0095] The reinforcing filler for component (C) may be exemplified by pyrolytic silica and / or precipitated silica and / or colloidal silica. Typically, these are provided in a finely dispersed form (i.e., they do not aggregate / stick together). Precipitated silica, pyrolytic silica, and / or colloidal silica are particularly preferred due to their relatively high surface area (typically at least 50 m² / g (BET method according to ISO 9277: 2010)). Fillers with surface areas of 50 m² / g to 450 m² / g (BET method according to ISO 9277: 2010) are typically used, and alternatively 50 m² / g to 300 m² / g (BET method according to ISO 9277: 2010). All these types of silica are commercially available.

[0096] Such reinforcing fillers (e.g., untreated silica fillers) are typically naturally hydrophilic and therefore difficult to mix with substantially hydrophobic silicone polymers. Therefore, these fillers are often treated with a treatment agent to make them hydrophobic. Once hydrophobically modified, such reinforcing fillers (C) do not clump and can be uniformly incorporated into the polydiorganosiloxane polymer (A). Surface treatment makes the filler readily wettable by the polydiorganosiloxane polymer (A).

[0097] Surface treatment is typically achieved using low molecular weight organosilicon compounds known in the art. These low molecular weight organosilicon compounds may include organosilanes, polydiorganosiloxanes, and / or organosilazanes (e.g., hexaalkyldisilazanes and short-chain siloxane diols), which can coat fillers and make them hydrophobic, and are therefore easier to process and obtain homogeneous mixtures with other components (components), particularly component (A). Specific examples include, but are not limited to, silanol-terminated trifluoropropylmethylsiloxane, silanol-terminated vinylmethyl (ViMe)siloxane, silanol-terminated methylphenyl (MePh)siloxane, liquid hydroxydimethyl-terminated polyorganosiloxane containing an average of 2 to 20 repeating units of diorganosiloxane per molecule, hexaorganodisiloxanes such as hexamethyldisiloxane, divinyltetramethyldisiloxane; hexaorganodisilazanes such as hexamethyldisilazane (HMDZ), divinyltetramethyldisilazane and tetramethyldi(trifluoropropyl)disilazane; hydroxydimethyl-terminated polydimethylmethylvinylsiloxane, octamethylcyclotetrasiloxane and silanes, including but not limited to methyltrimethoxysilane, dimethyldimethoxysilane, vinyltrimethoxysilane, methyltriethoxysilane, vinyltriethoxysilane, trimethylchlorosilane, dimethyldichlorosilane, trichloromethylsilane. A small amount of water can be added together with the silica treatment agent, which is used as a processing aid.

[0098] Surface treatment can be performed before or in situ before introduction into the composition (i.e., by blending these components together at room temperature or higher until the filler is fully treated, in the presence of at least a portion of the other components of the composition herein). Typically, untreated reinforcing filler (C) is treated in situ with a treatment agent in the presence of a polydiorganosiloxane polymer (A), which results in the preparation of a silicone elastomer matrix material that can then be blended with the other components.

[0099] Based on the weight percentage of the composition, the amount of reinforcing filler (C) present is from 5.0% to 40% by weight of the composition, or alternatively from 7.5% to 35% by weight of the composition, or alternatively from 10.0% to 30% by weight of the composition.

[0100] Alternatively and / or additionally, component (C) may include non-reinforcing fillers. Non-reinforcing fillers may include, for example, pulverized quartz, precipitated calcium carbonate, heavy calcium carbonate, diatomaceous earth, barium sulfate, iron oxide, titanium dioxide and carbon black, talc, wollastonite, alumina, calcium sulfate (anhydrous gypsum), gypsum, calcium sulfate, magnesium carbonate, clays such as kaolinite, aluminum hydroxide, magnesium hydroxide (brucite), graphite, copper carbonate (e.g., malachite), nickel carbonate (e.g., zarachite), barium carbonate (e.g., pyrite), and / or strontium carbonate (e.g., strontium strontium).

[0101] Other non-reinforcing fillers may include alumina, silicates selected from the group consisting of: olivine; garnet; aluminosilicates; cyclosilicates; chain silicates; and platy silicates. Olivine includes silicate minerals such as, but not limited to, forsterite and Mg2SiO4. Garnet includes ground silicate minerals such as, but not limited to, pyrope; Mg3Al2Si3O4. 12 Grossular garnet and Ca2Al2Si3O 12 Aluminosilicates include milled silicate minerals such as, but not limited to, sillimanite; Al₂SiO₅; mullite; 3Al₂O₃·2SiO₂; kyanite; and Al₂SiO₅. Cyclosilicates can be used as non-reinforcing fillers; these include silicate minerals such as, but not limited to, cordierite and Al₃(Mg,Fe)₂[Si₄AlO₂]. 18 Chain silicates include ground silicate minerals, such as, but not limited to, wollastonite and Ca[SiO3]. Flake silicates may alternatively or additionally be used as non-reinforcing fillers, wherein suitable classes contain silicate minerals, such as, but not limited to, mica; K2Al 14 [Si6Al2O 20 (OH)4; pyrophyllite; Al4[Si8O 20 (OH)4; Talc; Mg6[Si8O 20(OH)4; serpentine, for example asbestos; kaolinite; Al4[Si4O] 10 (OH)8; and vermiculite. In an alternative, the filler will be selected from one or more of the following: pyrolytic silica, precipitated silica, calcium carbonate, talc, mica, quartz, and alumina. If desired, any non-reinforced filler may also be treated with the above-mentioned treatment agents to make them hydrophobic.

[0102] Component (D)

[0103] Component (D) of the curable silicone elastomer composition described above is an organopolysiloxane adhesion promoter having the following structure:

[0104]

[0105] Each subscript n independently has an average value of 2 to 18, or alternatively an average value of 2 to 15, or alternatively an average value of 2 to 12, or alternatively an average value of 2 to 10, or alternatively an average value of 2 to 6, or alternatively an average value of 2 to 4.

[0106] As can be seen from the above structure, each R 2 The group is attached to the silicon that forms part of the siloxane ring, rather than to the silicon in the straight chain. In R 2 When H forms a Si-H bond, this bond is sometimes called a D bond. H Si-H bonding.

[0107] Each R 1 It is an independently selected monovalent hydrocarbon group, independently selected from aliphatic hydrocarbon groups, substituted aliphatic hydrocarbon groups, aromatic groups, or substituted aromatic groups, wherein the term substituted has the same definition as previously provided. Each aliphatic hydrocarbon group may be exemplified by, but is not limited to, alkyl groups having 1 to 20 carbons / groups, alternatively 1 to 15 carbons / groups, alternatively 1 to 12 carbons / groups, alternatively 1 to 10 carbons / groups, alternatively 1 to 6 carbons / groups, or cycloalkyl groups, such as cyclohexyl. Specific examples of alkyl groups may include methyl, ethyl, propyl, pentyl, octyl, undecyl, and octadecyl groups, alternatively methyl and ethyl groups. Examples of aromatic groups or substituted aromatic groups are phenyl groups and substituted phenyl groups having substituted groups as described above.

[0108] Each R 2 The group consisting of hydrogen (H), an organic moiety containing an epoxy group, and an organic moiety containing an anhydride group is selected independently.

[0109] When R 2When it is an organic moiety containing an epoxy group, it may contain an alkyl epoxy group or an alkyl glycidyl ether with the following structure:

[0110]

[0111] And its branched isomers, wherein the subscript t can be the same or different and is 2 to 30, alternatively, the subscript t is 2 to 20, alternatively, the subscript t is 2 to 15, alternatively, the subscript t is 2 to 10.

[0112] The term anhydride functional group refers to an organic moiety containing an anhydride group that has a group having the structure -C(=O)-OC(=O)-, which may or may not be cyclic. The anhydride functional group can be introduced onto the ring of component D by a hydrosilylation reaction between the alkenyl group of a compound containing both an anhydride group and an alkenyl group (e.g., a vinyl group) and the Si-H group of a cyclic siloxane described above, such as a straight-chain or branched unsaturated anhydride, for example, anhydride-Z. 1 -Vinyl, where Z 1 The group is a straight-chain or branched alkylene chain having 1 to 20 carbons.

[0113] Unsaturated anhydrides include maleic anhydride, succinic anhydride, and alkenyl succinic anhydride, such as allyl succinic anhydride and polyisobutylene succinic anhydride (PIBSA); citrate anhydride, oxalic anhydride, and phthalic anhydride group, namely crotonic anhydride, dibenzoic anhydride, indigo anhydride, itaconic anhydride, phenylmaleic anhydride, nadic anhydride, 3-(but-3-enyl)-1,2,3,6-tetrahydrophthalic anhydride, and cis-1,2,3,6-tetrahydrophthalic anhydride and phenylsuccinic anhydride. In one embodiment, the unsaturated anhydride is selected from maleic anhydride, succinic anhydride, allyl succinic anhydride, oxalic anhydride, and phthalic anhydride.

[0114] For example, when R 2 When it is an organic moiety containing an anhydride group. The anhydride functional group can be, and preferably is, a cyclic anhydride, i.e., a five- or six-membered ring, wherein the single-bonded oxygen and carbonyl carbon are part of the ring of bonded atoms, such as maleic anhydride groups having, for example, the following structure:

[0115]

[0116] And its branched isomers, where the subscript t is as described above.

[0117] Each component (D) molecule contains a certain number of R molecules. 2 Groups. The actual number depends on the size of the siloxane ring, but typically there are four or more R groups per molecule on average. 2Group. As previously noted, conditions exist regarding the structure of the adhesion promoter (D). The prerequisite is:

[0118] Each R per molecule 2 Is it H or

[0119] Each molecule contains R 2 A mixture of groups, the R 2 The group consists of one or more organic moieties containing an epoxy group and one or more H groups; or

[0120] Each molecule contains R 2 A mixture of groups, the R 2 The group consists of one or more organic moieties containing an anhydride group and one or more H atoms.

[0121] Therefore, for example, when each molecule of component (D) contains R consisting of one or more organic moieties containing epoxy groups and one or more H groups. 2 A mixture of groups (forming Si-H bonds with silicon) makes R in the molecule 2 The total number of groups is Z, where:

[0122]

[0123] Therefore, if Z=4, that is, component (D) contains four Rs. 2 A group, then it can contain any combination of two types of groups, that is,

[0124] An organic moiety comprising an epoxy group and three H groups, and therefore containing three Si-H bonds.

[0125] Two organic moieties, which contain an epoxy group and two H groups, or

[0126] It has three organic parts, which contain an epoxy group and an H group.

[0127] Similarly, if, for example, each molecule of component (D) contains R consisting of one or more organic moieties comprising anhydride groups and one or more H groups... 2 A mixture of groups, when there are a total of five R groups in the molecule. 2 A group, or component (D) molecule, contains five R groups. 2 When a group is used, it can contain any combination of two types of groups, that is,

[0128] An organic moiety comprising an anhydride group and four H groups.

[0129] Two organic moieties, which contain an anhydride group and three H groups, or

[0130] Three organic moieties, which contain an anhydride group and two H groups, or

[0131] It has four organic parts, each containing an anhydride group and an H group.

[0132] In each of the above alternatives, it should be understood that, depending on the conditions, when each molecule of component (D) contains R consisting of one or more organic moieties comprising an epoxy group and one or more H groups (forming Si-H bonds). 2 When the groups are mixed, only the organic moiety containing an epoxy group and one or more H groups is considered as R. 2 The radical is present, and each molecule of component (D) contains R consisting of one or more organic moieties comprising an anhydride group and one or more H groups. 2 When the groups are mixed, only the organic moiety containing an anhydride group and one or more H groups is considered as R. 2 exist.

[0133] In each of the above cases, in the preferred embodiment, at least two H groups (forming Si-H bonds) act as R. 2 The group is present. In another alternative, up to four organic moieties containing epoxy groups or up to four organic moieties containing anhydride groups are present at R per molecule component (D). 2 The proportion of functional groups exists. Alternatively, up to three organic structural moieties containing epoxy groups or up to three organic structural moieties containing anhydride groups are used as R per molecule of component (D). 2 The proportion of functional groups exists.

[0134] Alternatively, up to two organic moieties containing epoxy groups or up to two organic moieties containing anhydride groups, at R per molecule of component (D) 2 The proportion of functional groups exists.

[0135] In a preferred embodiment, each siloxane ring in component (D) has

[0136] One or two organic moieties containing epoxy groups, or

[0137] One or two organic moieties containing anhydride groups, which are expressed as R per molecule of component (D). 2 The proportion of groups present, alternatively, each molecule of component (D) contains one organic moiety containing an epoxy group or at most one organic moiety containing an anhydride group. In each of the above, the remaining R 2 The radical is hydrogen (H).

[0138] The following describes three examples of adhesion promoters (D), where n is 2 and Z is 6 for each.

[0139]

[0140] In the above text, all R 2 The group is an H group, which leads to the presence of -Si-H bonds.

[0141]

[0142] In the above text, there exists an organic moiety containing an epoxy group per siloxane ring, and the remaining R 2 The radical is H.

[0143]

[0144] In the above text, there exists an organic moiety containing an anhydride group in each siloxane ring, and the remaining R2 group is H.

[0145] Component (D), namely the adhesion promoter, is typically present in the composition in an amount of about 0.1% to 6% by weight; alternatively, it is present in the composition in an amount of 0.1% to 4% by weight.

[0146] Additional optional ingredients

[0147] Depending on their intended end use, additional optional components may be present in the curable silicone elastomer compositions described above. Examples of such optional components include curing inhibitors, pot life extenders, flame retardants, lubricants, MQ resins such as vinylated or non-vinylated MQ resins; pigments and / or colorants, bactericides, wetting agents, heat stabilizers, and compression set additives, as well as mixtures thereof.

[0148] Curing inhibitor

[0149] When the curable silicone elastomer composition described above is cured via an addition / hydrosilanization reaction, curing inhibitors can be used to suppress the curing of the composition. These curing inhibitors are used to prevent premature curing during storage and / or to achieve a longer working time or pot life of the hydrosilanized cured composition by delaying or inhibiting the activity of the catalyst. Curing inhibitors for the hydrosilanization catalyst (B)(ii) (e.g., platinum-based catalysts) are well known in the art and may include hydrazine, triazole, phosphine, thiols, organonitrogen compounds, alkynols, silylated alkynols, maleic esters such as dibutyl maleate; fumarates, alkenyl or aromatic unsaturated amides, alkenyl unsaturated isocyanates, olefinic siloxanes such as tetramethyltetravinylcyclotetrasiloxane; unsaturated hydrocarbon monoesters and diesters, conjugated alkenylenes, hydroperoxides, nitriles, and diazinonidium. Alkenyl-substituted siloxanes as described in US 3,989,667 may be used, with cyclic methylvinylsiloxanes being preferred.

[0150] Known curing inhibitors for hydrosilylation catalysts, such as platinum catalysts (B)(ii), include alkynyl compounds disclosed in US 3,445,420. Alynyl alcohols, such as 2-methyl-3-butyn-2-ol, constitute a preferred class of curing inhibitors, which inhibit the activity of platinum-containing catalysts at 25°C. Compositions containing these curing inhibitors typically require heating to 70°C or higher to achieve a practical curing rate.

[0151] Examples of alkynols and their derivatives include 1-ethynyl-1-cyclohexanol (ETCH), 2-methyl-3-butyn-2-ol, 3-butyn-1-ol, 3-methylbutynol, 3-butyn-2-ol, propargyl alcohol, 2-phenyl-2-propyn-1-ol, 3,5-dimethyl-1-hexyn-3-ol, 1-ethynylcyclopentanol, 1-phenyl-2-propynol, 3-methyl-1-penten-4-yn-3-ol, and mixtures thereof. In an alternative, the curing inhibitor is selected from one or more of 1-ethynyl-1-cyclohexanol (ETCH), tetramethyltetravinylcyclotetrasiloxane, 3-methylbutynol, and / or dibutyl maleate.

[0152] When present, a curing inhibitor concentration of as low as 1 mole of inhibitor / mole of catalyst (B)(ii) in the metal will, in some cases, impart satisfactory storage stability and curing rate. In other cases, a curing inhibitor concentration of up to 500 moles of curing inhibitor / mole of catalyst (B)(ii) in the metal is required.

[0153] The mixture described above may also be used. Depending on the concentration and form of the selected curing inhibitor provided / commercially available, when present in the composition, the curing inhibitor is typically present in amounts of 0.0001% to 10% by weight of the composition, alternatively 0.001% to 5% by weight of the curing inhibitor, alternatively 0.0125% to 5% by weight of the composition, and in higher amounts is a curing inhibitor masterbatch comprising the curing inhibitor and, for example, an organopolysiloxane or saturated equivalent containing at least two alkenyl groups as defined in component (A) above.

[0154] Pot life extenders, such as triazoles, may be used, but are not considered essential within the scope of this invention. Therefore, curable silicone elastomer compositions may be free of pot life extenders unless deemed necessary for a particular application.

[0155] Examples of flame retardants include chlorinated paraffins, hexabromocyclododecane, triphenyl phosphate, dimethyl methylphosphonate, tris(2,3-dibromopropyl) phosphate (tribromophosphate), and mixtures or derivatives thereof. When present in the composition, such flame retardants may be present in an amount from 5% to 50% by weight of the composition, if desired.

[0156] Examples of lubricants include tetrafluoroethylene, resin powder, graphite, fluorinated graphite, talc, boron nitride, fluorinated oil, silicone oil, molybdenum disulfide, and mixtures or derivatives thereof.

[0157] MQ resin

[0158] The composition may also include one or more MQ silicone resins, which can be synthesized by hydrolysis and condensation of alkoxysilanes and chlorosilanes. Alternatively, the MQ resin can be synthesized by polymerization of an aqueous alkali metal silicate in the presence of an acid, followed by reaction with a triorganoalkoxysilane, a triorganochlorosilane, a hexaorganodisiloxane, or a mixture thereof.

[0159] Typically, MQ resin (when present) contains SiO2. 4 / 2 (Q) Siloxane unit and R 4 3SiO 1 / 2 (M) siloxane units, wherein each R 4 They can be the same or different and represent monovalent groups selected from hydrocarbon groups, having 1 to 20 carbon atoms and alternatively 1 to 12 carbon atoms. A suitable R... 4 Examples of groups include alkyl groups, such as methyl, ethyl, propyl, pentyl, octyl, undecyl, and octadecyl groups; alicyclic groups, such as cyclohexyl; alkenyl groups having 2 to 12 carbons, such as vinyl, propenyl, butenyl, pentenyl, and hexenyl; alkynyl groups selected from ethynyl, propynyl, butynyl, pentynyl, or hexynyl; aryl groups, such as phenyl, tolyl, xylyl, benzyl, α-methylstyryl, and 2-phenylethyl; and alternatively, R 4 The group is a vinyl, methyl, ethyl, or phenyl group, such as the preferred R group. 2 3SiO 1 / 2 Examples of (M) siloxane units include Me3SiO 1 / 2 PhMe2SiO 1 / 2 ViMe2SiO 1 / 2 and Ph2MeSiO 1 / 2 In this context, Me represents methyl, Vi represents vinyl, and Ph represents phenyl. Silicone resins can be a single silicone resin or a mixture containing two or more different silicone resins (each described above). Typically, these silicone resins are ViMe₂SiO₂. 1 / 2 Unit and Me3SiO 1 / 2 and / or PhMe2SiO 1 / 2 MQ resin with a combination of functional groups.

[0160] In addition, MQ resin may contain residual OZ. 5 Z 5It can represent hydrogen or alkyl groups. After the synthesis of silicone MQ resin, OZ... 5 The group retained on component Q indicates incomplete condensation during the reaction that produces MQ resin, provided that the oz. 5 The content meets the above requirements for each mole of Si hydroxyl groups. Residual OZ 5 This is inherent to the methods and reactions used to prepare MQ resins. MQ resins can also undergo subsequent methylsilanization to further minimize residual OZ. 5 .

[0161] MQ resins are typically delivered in hydrocarbon or silicone solvents without solvent. Silicone resins are typically solid, but it is preferred herein that MQ resins are delivered in silicone solvents such as nonfunctionalized polydimethylsiloxanes or polydimethylsiloxanes containing two or more alkenyl groups per molecule (such as component (a) of this document, for example).

[0162] For example, the molar ratio of M siloxane units to Q siloxane units has values ​​of 0.5:1 to 1.2:1, alternatively 0.6:1 to 1.1:1, alternatively 0.8:1 to 1.1:1, and alternatively 0.9:1 to 1.1:1. In one embodiment, the MQ resin includes a resin portion wherein the M units are bonded to SiO2. 4 / 2 The siloxane unit (i.e., the Q unit), and each Q unit in the Q unit is bonded to at least one other SiO2. 4 / 2 (Q) Siloxane unit. The molar ratio of M unit to Q unit is 0.3:1 to 1.2:1, alternatively 0.4:1 to 1.1:1, alternatively 0.5:1 to 1:1, or alternatively 0.6:1 to 0.9:1. Such MQ resins suitable as components may have a number average molecular weight (Mn) of 2000 g / mol to 50,000 g / mol, or alternatively 3,000 g / mol to 30,000 g / mol.

[0163] In one embodiment, the silicone resin can be described, based on its mole fraction, as an MQ silicone resin having the following formula:

[0164]

[0165] Each R 4 They can be the same or different, and are hydrocarbon groups, preferably C1 to C2. 10 Alkyl groups, C2 to C3 groups selected from alkenyl or ynyl groups 10 Unsaturated groups, or mixtures thereof. Typically, the structure is (R... 4 3SiO 1 / 2 ) u (SiO 4 / 2 ) v The MQ resin will have at least some M groups, wherein at least one R4 The group is an unsaturated group, and another R is selected. 4 The group is an alkenyl group containing 2 to 6 carbons, optionally an vinyl group. In an alternative, each M group has at least one R 4 It is an alkenyl group, usually a vinyl group; in this case, the M group can be called M. Vi Group. Furthermore, u and v are mole fractions, where the value of u+v is 1.0. In one embodiment, when present, u is 0.3 to 0.6, alternatively 0.37 to 0.52, v is 0.4 to 0.7, alternatively 0.48 to 0.63, and the value of u+v is 1.0.

[0166] Examples of pigments and other colorants that can be used in curable silicone elastomer compositions include pigments, vat dyes, reactive dyes, acid dyes, chromium dyes, disperse dyes, cationic dyes, and mixtures thereof. The curable silicone elastomer compositions described herein may also contain one or more pigments and / or colorants, which may be added if desired. Pigments and / or colorants can be colored, white, black, metallic, and luminescent, such as fluorescent and phosphorescent. Pigments are used to color the composition as needed. Any suitable pigments that are compatible with the compositions described herein may be utilized.

[0167] Suitable white pigments and / or colorants include titanium dioxide, zinc oxide, lead oxide, zinc sulfide, zinc barium white, zirconium oxide, and antimony oxide.

[0168] Suitable non-white inorganic pigments and / or colorants include, but are not limited to, iron oxide pigments such as goethite, lepidocrocite, hematite, maghemite, and maghemite black, yellow, brown, and red iron oxides; blue iron pigments; chromium oxide pigments; cadmium pigments such as cadmium yellow, cadmium red, and cadmium cinnabar; bismuth pigments such as bismuth vanadate and bismuth vanadate; mixed metal oxide pigments such as cobalt titanate green; chromate and molybdate pigments such as chrome yellow, molybdenum red, and molybdenum orange; ultramarine pigments; cobalt oxide pigments; nickel antimony titanate; lead chromium; carbon black; lampblack; and metallic effect pigments such as aluminum, copper, copper oxide, bronze, stainless steel, nickel, zinc, and brass.

[0169] Suitable organic non-white pigments and / or colorants include phthalocyanine pigments, such as phthalocyanine blue and phthalocyanine green; monoaryl yellow, diaryl yellow, benzimidazolone yellow, heterocyclic yellow, DAN orange, quinacridone pigments, such as quinacridone fuchsin and quinacridone violet; organic reds, including metallized azo red and non-metallized azo red, as well as other azo pigments, monoazo pigments, diazo pigments, azo pigment lakes, β-naphthol pigments, naphthol AS pigments, benzimidazolone pigments, diazo condensation pigments, isoindolineone and isoindoline pigments, polycyclic pigments, perylene and violet ketone pigments, thioindigo pigments, anthraquinone pigments, yellow anthrone pigments, anthraquinone pigments, dioxazine pigments, triarylcarbamonite pigments, quinacridone pigments, and diketopyrrolopyrrole pigments.

[0170] Typically, pigments and / or colorants, when in particulate form, have an average particle size in the range of 10 nm to 50 µm, preferably in the range of 40 nm to 2 µm. Pigments and dyes can be used in the form of pigment masterbatches composed of which they are dispersed in component (a) at a ratio of 25:75 to 70:30.

[0171] The curable silicone elastomer composition can be heat-stable. Examples of heat stabilizers may include metal compounds such as iron oxide red, iron oxide yellow, iron hydroxide, cerium oxide, cerium hydroxide, lanthanum oxide, copper phthalocyanine, pyrolytic titanium dioxide, iron naphthenate, cerium naphthenate, dimethylpolysiloxane cerium, and acetylacetone salts of metals selected from copper, zinc, aluminum, iron, cerium, zirconium, titanium, etc. Other examples of heat stabilizers may include suitable antioxidants or metal scavengers such as 1,2-bis(3,5-di-tert-butyl-4-hydroxycinnamoyl)hydrazine, 2-hydroxy-N-1H-1,2,4-triazol-3-ylbenzamide, and N'1,N'12-bis(2-hydroxybenzoyl)dodecanedihydrazine. When present in the curable silicone elastomer composition, the amount of heat stabilizer may range from 0.01% by weight to 1.0% by weight of the curable silicone elastomer composition.

[0172] Unless the composition is used immediately after preparation, it is stored in two parts, usually referred to as part A and part B, to keep component (B) (i) (an organosilicon compound having at least two or three Si-H groups per molecule, which is used as a crosslinking agent) and component (B) (ii) (a hydrosilane curing catalyst) separate to avoid premature curing.

[0173] Typically, part A of the composition will contain the following components:

[0174] (A) Polymer,

[0175] (C) One or more optional fillers as defined above, and

[0176] (B)(ii) Hydrogenated silanization curing catalyst, and

[0177] Part B will include:

[0178] (A) Polymer,

[0179] (C) One or more optional fillers as defined above,

[0180] (B)(ii) Organosilicon compounds having at least two or at least three Si-H groups per molecule, which are used as crosslinking agents, and

[0181] Curing inhibitor (if present).

[0182] Component (D) adhesion promoters are typically stored in part of the B composition due to their Si-H content.

[0183] When present, other optional additives may be included in portion A or portion B, provided that they do not adversely affect the properties of any other present components (e.g., through catalyst deactivation). Portions A and B of the hydrogenable silanizable curable silicone elastomer composition described herein are mixed together shortly before use to initiate the curing of the entire composition into a silicone elastomer material. Portions A and B can be designed to be mixed in any suitable ratio (e.g., by weight). For example, portions A and B can be mixed at a weight ratio of 100:1 to 1:100, alternatively 10:1 to 1:10, alternatively 5:1 to 1:5, but most preferably 1:1.

[0184] The components of each of Part A and / or Part B are mixed individually or in a pre-prepared combination into their respective part compositions to facilitate, for example, mixing of the final composition. For instance, components (A) and (C) are typically mixed together before the introduction of other components to form a liquid silicone rubber (LSR) base. These can then be mixed with other components of the directly prepared part or used to prepare a pre-formulated concentrate commonly referred to in the industry as a masterbatch. For example, if desired, component (D) may also be pre-mixed with some components (A) of component (A) in the Part B composition to form a “masterbatch” before being mixed with other Part B components.

[0185] In this case, to facilitate mixing of the components, one or more masterbatches can be used to successfully mix the components to form a composition of part A and / or part B.

[0186] Parts A and B of the hydrogenated silanized curable silicone rubber elastomer composition can be prepared by combining all their respective components at ambient temperature. Any mixing techniques and equipment described in the prior art can be used for this purpose. The specific equipment to be used will depend on the components and the viscosity of the final composition. Suitable mixers may include, but are not limited to, kneading mixers, Z-blade mixers, two-roll mills (open mills), three-roll mills, and Haake mills. ® Rheomix OS Lab mixers, screw extruders, or twin-screw extruders, etc., may also be used. Alternatively, high-speed mixers, such as those sold by Hauschild as DC 150.1 FV, DAC400 FVZ, or DAC 600 FVZ, may be used. Cooling during mixing may be desirable to prevent premature curing of the composition.

[0187] This document provides a method for preparing articles using the curable silicone elastomer composition described herein, the method comprising the following steps:

[0188] 1) A curable silicone elastomer composition is disposed on a substrate; and

[0189] 2) Curable silicone elastomer composition on a cured substrate.

[0190] As previously mentioned, when the curable silicone elastomer composition is a hydrogenated silanized curable silicone elastomer composition, unless the composition is to be used immediately, the composition is stored in two parts (part A and part B) and mixed together in the desired weight ratio prior to step (1) above (unless otherwise specified).

[0191] Curable silicone elastomer compositions can be processed (or cured) by injection molding, compression molding, extrusion, transfer molding, pressure vulcanization, and calendering.

[0192] Curing can occur, for example, in a mold to form a molded silicone article that adheres to, for example, a thermoplastic substrate. The curable silicone elastomer composition can be, for example, injection molded to form an article that adheres to a thermoplastic material, or the composition can be overmolded by injection molding around or on a thermoplastic substrate, an organic resin substrate, or a thermoplastic and organic resin substrate or article. When cured in the presence of a heat-sensitive substrate, the curable silicone elastomer composition described below is cured under conditions that enable mechanical adhesion to the heat-sensitive substrate, etc., and more specifically, by using a temperature and curing time that prevents the heat-sensitive substrate from deforming, melting, or degenerating.

[0193] Specific examples of suitable substrates include acrylonitrile-butadiene-styrene, polyphenylene / styrene blends, polystyrene, polyoxymethylene (POM); polyurethanes, styrene resins, polyolefins such as polyethylene, polypropylene and polybutene, polyacrylic acids such as polyacrylates, polymethacrylates such as polymethyl methacrylate (PMMA); polyacrylamide, polyesters such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polypropylene terephthalate (PTT), polyethylene naphthalate (PEN); copolyesters, polyphenylene ether, polyphenylene sulfide, polysulfone; polyamides (PA), such as nylon 6 (PA 6), nylon 6,6 (PA 6). 6,6) and nylon 6,10; blends of polyamide resins with syndiotactic polystyrene, polyimide, and polyvinyl chloride (PVC); polyphenylene sulfide (PPS); polyphenylene ether (PPE); polyimide (PI); polyamide-imide (PAI); polyetherimide (PEI); polysulfone (PSU); polyethersulfone; polyketone (PK); polyetherketone; polyvinyl alcohol (PVA); polyetheretherketone (PEEK); polyetherketoneketone (PEKK); polyarylate (PAR); polyether nitrile (PEN); phenolic resins; phenoxy resins; fluoropolymers and liquid crystal resins, resin-free polyetherimides; phenolic resins, epoxy resins, epoxy molding compounds, urea resins, melamine resins, alkyd resins, acrylonitrile-butadiene-styrene, styrene-modified poly(phenylene ether), poly(phenylene sulfide), vinyl esters, or polyphthalamides. If appropriate, any of the above may be reinforced with, for example, glass fiber.

[0194] In one embodiment, the substrate may be a glass fiber reinforced polyester, such as glass fiber reinforced polybutylene terephthalate (PBT), or a glass fiber reinforced polyamide, such as nylon 6 (PA 6), nylon 6,6 (PA 6,6) and nylon 6,10, in each case of glass fiber reinforcement.

[0195] Curing can be carried out by any convenient means. For example, a curable silicone elastomer composition can be cured by heating at elevated temperatures (e.g., 50°C to 200°C, alternatively 50°C to 180°C, alternatively 50°C to 160°C, alternatively 50°C to 150°C, alternatively 75°C to 150°C, alternatively 90°C to 150°C) to obtain a composite article comprising a cured silicone elastomer material (prepared by curing the curable silicone elastomer composition) adhered to a substrate. The curing temperature used needs to be below the melting point and / or softening point of the substrate to maintain the desired composite structure. Therefore, those skilled in the art will be able to select an appropriate temperature based on various factors, including the selection of optional starting materials and the substrate material used in the curable silicone elastomer composition.

[0196] The curable silicone elastomer composition can be cured at an elevated temperature for a period of time. This period of time is generally sufficient to achieve curing, i.e., crosslinking, of the curable silicone elastomer composition. This period of time can be greater than 0 hours to 8 hours, alternatively greater than 0 hours to 2 hours, alternatively greater than 0 hours to 1 hour, alternatively greater than 0 minutes to 30 minutes, alternatively greater than 0 minutes to 15 minutes, alternatively greater than 0 minutes to 10 minutes, alternatively greater than 0 minutes to 5 minutes, or alternatively greater than 0 minutes to 2 minutes. This period of time depends on various factors, including the elevated temperature used, the selected temperature, the desired thickness of the cured silicone, and the presence or absence of any solvent in the curable silicone elastomer composition.

[0197] Curable silicone elastomer compositions are designed to achieve significant adhesion upon curing to thermoplastic substrates, organic resin substrates, or surfaces of both thermoplastic and organic resin substrates, and preferably not to metal surfaces, thereby forming articles and / or composite parts with the substrates listed above. Such articles can be used in a variety of industries, including but not limited to automotive, medical, consumer and industrial, and electronic applications.

[0198] And depending on the manufacturer's size specifications, it may include, for example, tubes, belts, solid ropes or custom profiles.

[0199] In automotive applications, this can include housings with silicone seals or gaskets for plugs (e.g., spark plugs and other connector seals), assemblies for various sensors, diaphragms, airbags and climate exhaust components, spark plug caps, assemblies for various sensors and other automotive components, etc.

[0200] Electronic applications may include mobile phone cover seals, mobile phone accessories, precision electronic devices, electronic switches and switch covers, toothbrushes, watches and wristbands, wearable devices (e.g., face masks) and wearable electronic devices, etc.

[0201] Composite components may also be selected from components of: mobile telecommunications equipment (e.g., mobile phones); game consoles, clocks, and image receivers; media playback devices, such as DVD and CD equipment; and in televisions, such as thin displays in LCD and plasma TVs, as well as other sophisticated electronic equipment. They may also be used in consumer products such as microwave ovens, refrigerators, rice cookers, vacuum cleaners, hand dryers, and office automation (OA) equipment (such as copiers, printers, and fax machines).

[0202] In one embodiment, the silicone elastomer composition as described above can be used as a coating for coating airbags, etc. In such an embodiment, the silicone elastomer composition as described above can be applied to a fabric substrate, typically a one-piece woven or flat fabric airbag substrate, by any suitable known technique. These methods include spraying, gravure coating, bar coating, doctor blade coating, such as by roller doctor blade coating, by air doctor blade coating; padding, impregnation, and screen printing.

[0203] Hydrogenable silanization curable silicone elastomer compositions can be applied as a coating to one or both sides of a textile or fabric substrate (e.g., an airbag fabric to be cut into pieces and sewn together to assemble an airbag), or can be applied to an integral woven airbag.

[0204] The curing composition of this airbag coating, which is applied once to the woven fabric, is typically cured by heating the composition at a temperature of 150°C to 200°C for 45 seconds to 2 minutes, which can be done using a suitable oven or by drying through the drying tunnel of a circulating hot air oven.

[0205] Although not preferred, the composition can be applied via an iterative method, i.e., by applying multiple layers of the coating composition together having a predetermined average dry coating weight that can be measured according to ISO 3801. If deemed necessary, additional compatible coatings may also be applied to the coating composition, for example, a compatible coating of a material providing, for example, low friction.

[0206] Any suitable desired coating weight can be applied to textiles or fabric materials (such as airbags), for example, 15 g / m² as determined according to ISO 3801. 2 Up to 150g / m 2 , 15g / m 2 Up to 100g / m 2 , 20g / m 2 Up to 75g / m 2 The thickness of the coating layer ranges from 20 μm to 80 μm, depending on the coating weight.

[0207] In another embodiment, the curable silicone elastomer composition as described above can be applied to the surface of a substrate processed using a 3D printing method. The 3D printer can be selected from fused filament manufacturing printers, selective laser sintering printers, selective laser melting printers, stereolithography printers, powder bed (binder jet) printers, material jet printers, direct metal laser sintering printers, electron beam melting printers, laminated article manufacturing deposition printers, directional energy deposition printers, laser powder forming printers, polymer jet printers, inkjet printers, material jet printers, and syringe extrusion printers.

[0208] Typical methods for forming three-dimensional (3D) articles may include multiple steps. For example, the method may include (i) providing a thermoplastic substrate, an organic resin substrate, or a combination of both. The method may also include (ii) heating the substrate. Additionally, the method may include (iii) using a 3D printer to print a curable silicone elastomer composition as described above to form subsequent layers. Optionally, if one or more additional layers need to be applied, the latter step may be repeated. Example

[0209] A series of embodiments were carried out to evaluate the functionality of the proposed novel adhesion promoter.

[0210] Viscosities of all components (A) were measured using a Brookfield RVF viscometer that can be used with a rotor selected based on viscosity range and operated at the preferred rpm indicated below.

[0211] The viscosity of component (B) (i) was measured by capillary measurement according to ASTM D-445.

[0212] In the first series of embodiments, the compositions described in Table 1a were used in reference embodiments Ref. 1, Ex. 1, 2 and 3 and comparative example C. 1.

[0213] Table 1a: Compositions of Ref. 1, Ex. 1 to 3, C. 1 (wt%)

[0214]

[0215] In Table 1a:

[0216] MB 1 is a polydimethylsiloxane containing 70.8 parts by weight of dimethylvinylsiloxy-terminated polydimethylsiloxane with a viscosity of approximately 53,000 mPa·s at 25°C and 22.4 parts by weight of polydimethylsiloxane with a viscosity of approximately 300 mPa·s. 2 Masterbatch 1 for pyrolytic silica filler with a surface area of ​​ / g. The silica is hydrophobic and does not contain vinyl functionalization.

[0217] MB 2 is a polydimethylsiloxane containing 66.6 parts by weight of dimethylvinylsiloxy-terminated polydimethylsiloxane with a viscosity of approximately 55 Pa·s at 25°C and 25.8 parts by weight of a polydimethylsiloxane with a viscosity of approximately 300 m³ / s. 2 2. Masterbatch of pyrolytic silica filler with a surface area of ​​ / g. The silica is hydrophobic and has approximately 0.178 mmol / g vinyl functional groups;

[0218] Polymer 1 is a vinyl dimethyl-terminated polydimethylsiloxane with a viscosity of 53,000 mPa·s at 25°C. This viscosity is obtained using a Brookfield rotor 5.™ The RVF viscometer was used to measure the viscosity at 4 rpm.

[0219] Polymer 2 is a vinyl-terminated poly(dimethylsiloxane-co-methylvinylsiloxane) with a viscosity of 370 mPa·s at 25°C. This viscosity is obtained using Brookfield rotor 2 with RVF. ™ The RVF viscometer was used to measure the viscosity at 20 rpm.

[0220] X-linker 1 is a trimethyl-terminated polymethylhydrodimethylsiloxane (viscosity = 30 mPa·s at 25 °C).

[0221] The Pt catalyst is a Karstedt catalyst, which is a Pt2(divinyltetramethyldisiloxane)3 complex;

[0222] The inhibitor is 1-ethynyl-1-cyclohexanol (commonly known as ETCH);

[0223] The adhesion promoters used in the above compositions are as follows:

[0224] AP 1 has the following structure:

[0225]

[0226] AP 2 has the following structure:

[0227]

[0228] AP 3 has the following structure:

[0229]

[0230] AP 4 (comparative example) has the following structure:

[0231]

[0232] It should be noted that AP 4 does not contain any cyclic siloxanes.

[0233] As previously noted, liquid silicone rubber compositions are typically prepared in two parts to prevent premature curing during storage. For the accompanying laboratory examples, the compositions are fresh and intended for immediate use, and therefore, for practical purposes, it is not necessary to prepare the composition in two parts and then immediately mix them together. The expected results are the same as if the two-part composition had been prepared, mixed together, and used immediately, as no premature curing occurs.

[0234] In the first series of examples evaluating the adhesiveness of the silicone compositions in Table 1a, the aforementioned silicone compositions were first prepared, and then their adhesiveness was evaluated for the following:

[0235] (1) By BASF SE under the trade name Ultradur ™ B 4300 G4 is sold using a commercially available polybutylene terephthalate (PBT) substrate reinforced with 20% glass fiber; and

[0236] (2) By BASF SE under the trade name Ultramid ™ A3EG6 UNCOLORED sells glass fiber reinforced (30% by weight) polyamide 6,6 (PA 6,6) substrate.

[0237] In each case, a 25mm × 100mm substrate with a thickness of 3mm was cleaned with isopropanol and dried at 120°C for 18 hours. Before overmolding with one of the silicone compositions described in Table 1a above, the thermoplastic substrate was preheated at 150°C for 5 minutes. The thermoplastic substrate was overmolded with a 3mm thick layer of the corresponding silicone composition and compressed at 150°C and 30MPa (300 bar) for 5 minutes using a TP400 hot press, commercially available from Fontijne Presses BV in Delft, Netherlands.

[0238] To assess the adhesion level between silicone and the corresponding thermoplastic substrate, adhesion was tested using a floating roller apparatus with a 90° peel test, according to DIN EN ISO 22631 (“Adhesives – Test methods for adhesives for floor and wall coverings”). The tensile strength was measured at a tensile speed of 100 mm / min using an H10TMC tensile testing machine, commercially available from Richard Hess MBV GmbH, Sonsbeck, Germany. Peel strength was calculated as the average peel force divided by the sample width (25 mm) and reported in N / mm. The results are provided in Table 1b below.

[0239] Table 1b: Peel strength results on PBT and PA 6,6 substrates using the compositions described in Table 1a.

[0240]

[0241] It should be noted that in the reference examples where the silicone compositions do not contain adhesion promoters, adhesion completely fails. Surprisingly, AP 1 through AP 3 yielded acceptable / good adhesion levels, and perhaps even more surprisingly, AP 4 did not. The main difference between the structures of AP1 and AP 4 is that AP1 is cyclic, while AP 4 contains non-cyclic branched groups, and it appears that cyclic groups are required to provide adhesion promotion.

[0242] In another series of embodiments, adhesion levels were evaluated using a variety of crosslinking agents to determine whether the crosslinking agent used for hydrogen silanization curing was significant. The compositions used were compared with the compositions described in Ex.1 and Ex.2 of Table 1a.

[0243] Table 2a: Compositions (wt%) containing different crosslinking agents, Ex.1, 2, and 4 to 8, at the same SH content.

[0244]

[0245] In the table above, MB1, MB2, polymer 1, polymer 2, X-linker 1, Pt catalyst, inhibitor, AP1, and AP2 are all the same as defined above.

[0246] X-linker 2 is a trimethylsilyl-terminated poly(dimethyl-co-methylhydro)siloxane having 0.70% by weight H as Si-H and a thickness of approximately 48 mm at 25 °C. 2 Viscosity in cSt / s. H content in Si-H form is determined using quantitative infrared analysis according to ASTM E168-16 (2023).

[0247] X-linker 3 is HMe2SiO 0.5 The end-capped MHQ resin has 0.97% by weight H as Si-H, and a viscosity of 22 mmHg as determined by quantitative infrared spectroscopy using ASTM E168-16 (2023) for the H content in Si-H form. 2 / s(cSt).

[0248] X-linker 4 is a phenyltris(dimethylsilyloxy)silane having the following structure:

[0249]

[0250] X-linker 5 is HMe2SiO 0.5 End-capped (45% to 50% n-ethylhydrosiloxane) phenylmethylsiloxane copolymer, which has a 75mm diameter 2 / s to 110mm 2 Viscosity / s (cSt)

[0251] The amount of each crosslinking agent varies slightly, such that when the Si-H content of the corresponding crosslinking agent is combined with the Si-H content of the adhesion promoter present in the relevant formulation, each composition has the same Si-H content.

[0252] Each composition prepared underwent the same curing process and the same adhesion test as described above, and the results are provided in Table 2b below.

[0253] Table 2b: Peel strength results for PBT and PA 6,6 substrates using the compositions described in Table 2a.

[0254]

[0255] It should be understood that excellent results were obtained in every case, regardless of the crosslinking agent used in the composition.

[0256] In the third series of tests, the preparation, curing, and physical properties of the compositions described above (Ref. 1, Ex. 1, and C. 1), the second reference composition without an adhesion promoter, and the third comparative composition containing the standard adhesion promoter glycidoxypropyltrimethoxysilane (identified as AP 5 in Table 3a) were compared. The prepared compositions are depicted in Table 3a.

[0257] Table 3a: Compositions of Ref. 1, Ex. 1, C. 1, Ref. 2 and C. 2 (wt%)

[0258]

[0259] For physical property testing, the silicone composition was pressurized and cured at 120°C for 10 minutes using the TP400 hot press described above. No post-curing was performed.

[0260] The Shore A hardness tester is evaluated according to ASTM D 2240.

[0261] Tensile strength was evaluated using S2 type specimens according to DIN 53504.

[0262] The tear strength results were obtained according to ASTM D 624 B.

[0263] Compression set results were obtained according to ISO 815-1:2019 Method B (6 mm). Compression set buttons (6 mm thick) were obtained by pressure curing the LSR composition in a suitable mold at 175°C for 10 minutes. No post-curing was performed. Compression set was evaluated after 22 hours at 125°C.

[0264] Curing kinetics were evaluated according to ISO 3417 using a piston rheometer (MDR, Premier MDR from Alpha Technologies). Measurements were taken at 120°C over a 10-minute pressurization process. Tc2 and Tc60 represent the time to reach 2% and 60% of the maximum torque, respectively.

[0265] The results are depicted in Table 3b below:

[0266] Table 3b: Physical properties of the compositions described in Table 3a.

[0267]

[0268] Compared to the alternatives shown, the composition containing the adhesion promoter of the present invention in Ex.1 produces a unique combination of rapid curing, good physical properties and low compression set upon curing.

[0269] C.1 has rapid curing, good physical properties, low compression set, but no adhesiveness;

[0270] Ref. 2 exhibits poor adhesion, low tensile strength, and very high compressive settling.

[0271] C.2 has poor adhesion and very slow curing.

Claims

1. A curable silicone elastomer composition, said curable silicone elastomer composition being capable of adhesion to plastic / thermoplastic / resin material substrates, and comprising: (A) One or more organopolysiloxanes containing at least two alkenyl and / or alkynyl groups per molecule and having a viscosity in the range of 1,000 mPa·s to 750,000 mPa·s at 25°C; (B) A hydrogenated silane curing catalyst package, wherein the hydrogenated silane curing catalyst package comprises: (i) organosilicon compounds having at least two, alternatively at least three, Si-H groups per molecule; and (ii) Hydrosilylation catalyst; (C) One or more reinforcing fillers, one or more non-reinforcing fillers, or a mixture thereof; and (D) Organosiloxane adhesion promoters having the following structure: Each subscript n independently has an average value between 2 and 18. Each R 1 It is an independently chosen monovalent hydrocarbon group (or alternatively an alkyl group), and Each R 2 The group consisting of hydrogen (H), an organic moiety containing an epoxy group, and an organic moiety containing an anhydride group is selected independently. The prerequisite is that each R in each molecule 2 It's H, or Each molecule contains R 2 A mixture of groups, wherein R 2 The group consists of one or more organic moieties containing an epoxy group and one or more hydrogen (H) groups; or Each molecule contains R 2 A mixture of groups, wherein R 2 The group consists of one or more organic moieties containing an anhydride group and one or more hydrogen atoms (H).

2. The curable silicone elastomer composition according to claim 1, wherein R 2 An organic moiety comprising at least one alkyl glycidyl ether containing an alkyl epoxy group or having the following structure: And its branched isomers, wherein each subscript t can be the same or different, and is 2 to 30.

3. The curable silicone elastomer composition according to claim 1, wherein R 2 It comprises at least one organic moiety containing an anhydride group, said organic moiety containing a group having the structure -C(=O)-OC(=O)-, which can be cyclic.

4. The curable silicone elastomer composition according to claim 3, wherein R 2 It comprises at least one organic moiety containing an anhydride group, said organic moiety comprising a maleic anhydride group with the following structure: And its branched isomers, wherein each subscript t can be the same or different, and is 2 to 30.

5. The curable silicone elastomer composition according to any claim, wherein each subscript n in component D is an average of 2 to 6.

6. The curable silicone elastomer composition according to any claim, wherein each subscript n in component D is an average of 2 to 4.

7. The curable silicone elastomer composition according to any of the preceding claims, wherein component (D) is added to the composition in an amount of 0.5% to 5% by weight of the total composition of the other components.

8. The curable silicone elastomer composition according to any one of the preceding claims, wherein the curable silicone elastomer composition is stored in at least two separate portions prior to use.

9. A method for preparing an article or a composite component of an article, the method comprising: a) A mixture forming a curable silicone elastomer composition according to any of the preceding claims, and b) Apply the mixture to the 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°C to 200°C.

10. The method of claim 9, wherein the substrate is optionally a glass fiber reinforced polyamide or optionally a glass fiber reinforced polyester.

11. An article comprising a silicone elastomer material cured from a curable silicone elastomer composition according to any one of claims 1 to 8.

12. The article of claim 11, wherein the article is a composite component containing a silicone elastomer cured from a curable silicone elastomer composition according to claims 1 to 8, the silicone elastomer being adhered to a thermoplastic substrate, an organic resin substrate, or a thermoplastic and organic resin substrate.

13. The article of claim 11 or 12, wherein the article is a composite component containing a silicone elastomer cured from a curable silicone elastomer composition according to claims 1 to 8, the silicone elastomer being adhered to optionally glass fiber reinforced polyamide or optionally glass fiber reinforced polyester.

14. Use of the curable silicone elastomer composition according to claims 1 to 8 in the preparation of an article, the article comprising a cured elastomer material made from the composition, the cured elastomer material being adhered to a thermoplastic substrate, an organic resin substrate, or a thermoplastic and organic resin substrate.

15. Use of the composition of claim 14 in the preparation of an article, the article comprising a cured elastomer material made from the composition, the cured elastomer material being adhered to optionally glass fiber reinforced polyamide or optionally glass fiber reinforced polyester.

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