Silicone elastomer composition

Abstract

The present invention describes a curable silicone elastomer composition having enhanced adhesion properties to a variety of substrates. The compositions described herein are provided with a phenylmethylpolysiloxane-based additive that contains at least one, alternatively at least two, Si-H groups per molecule and at least one, alternatively at least two, epoxide functional groups per molecule. The phenylmethylpolysiloxane-based additive provides an elastomer having improved thermohumidity stability.

Description

[0001] The present disclosure relates to a curable silicone elastomer composition (hereinafter referred to as "curable silicone elastomer composition") having enhanced adhesion properties to a variety of substrates. The curable silicone elastomer composition described herein provides an organopolysiloxane having one, alternatively at least two, Si-H groups per molecule and at least one, alternatively at least two, epoxide functional groups per molecule. The organopolysiloxane-based additive provides an elastomer having thermal humidity (H&H) stability with respect to substrates of other materials, i.e., the elastomer made from the curable silicone elastomer composition provides improved adhesion after aging. Also provided are elastomers prepared by curing the foregoing composition, composites comprising the elastomer and an organic resin (including polymer-based substrates and composites, such as those formed from thermoplastic polymers and thermosetting resins), and methods of adhering the composition to an organic resin-based substrate.

[0002] The curable silicone elastomer composition cures to provide a silicone elastomer material (also referred to as silicone rubber). A suitable curing process is carried out via an addition curing mechanism, also described as a hydrosilylation method using a platinum group catalyst.

[0003] The curable silicone elastomer composition can be a curable silicone elastomer composition capable of adhering to a substrate made of a thermoplastic material, an organic resin-based material, or both a thermoplastic material and an organic resin-based material during curing, and these curable silicone elastomer compositions are placed in direct contact with the substrate before or during the curing process. In some cases, the curable silicone elastomer composition can be considered a composition having "selective adhesion" to the substrate in the industry. To avoid doubt, the term selective adhesion herein is intended to mean that, upon curing, the composition is capable of providing an adhesive bond directly to a thermoplastic or resin substrate without the need to apply, for example, a primer to the substrate surface, while being non-sticky to a metal substrate (such as a mold). In such cases, they are considered to have selective adhesion. The term "direct contact" is intended to be understood to mean that the adhesion properties of the curable silicone elastomer composition are such that no primer needs to be applied to the surface of a substrate made of a thermoplastic material, an organic resin-based material, or both a thermoplastic material and an organic resin-based material in order to achieve 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.

[0004] Silicone elastomers are used in a variety of applications, including (by way of example) in electrical and electronic, healthcare, cookware, and automotive applications, not least because of their highly reliable properties with respect to heat resistance, weather resistance, and electrical insulation. In automotive connector sealing applications, silicone elastomers can provide reliable sealing performance compared to many plastics, specifically in harsh environments. They provide reliable seals for the safe operation of automotive electronic control systems, thereby enhancing the safety and comfort experience of drivers and passengers. Silicone seals and coatings are also important for waterproofing and sealing components made of silicone elastomers in smart phones and wearable devices. However, in some applications, their use is limited because they cannot form a strong enough adhesive bond with plastics and thermoplastic substrates such as polycarbonate. 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 improving performance. Self-adhesive silicone elastomers can also be used as adhesives, sealants, 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, in-situ cured gaskets, headlamps, and appliances. Additionally, silicone elastomers that are self-adhesive to thermoplastic film substrates can also be used as release liners and release coatings.

[0005] This problem was initially overcome by applying a primer to the substrate surface. However, several problems have arisen with methods that require a primer or high-energy surface pretreatment (such as irradiation by exposure to plasma, corona, flame, UV, or a UV-ozone source to activate the surface for adhesion). The primer method is cumbersome, not least because it can lead to unreliable productivity, quality control issues, and indeed reliability issues with the components / articles being manufactured. The choice, storage, use, and processing of primers can also greatly affect the adhesion level, resulting in the need for special attention during storage prior to use. Therefore, the use of primers needs to be well controlled in order to achieve good adhesion, and such methods are generally time-consuming and can result in low productivity and seals of uneven quality. Thus, if possible, it is desirable to avoid the use of primers, which has subsequently been achieved by using self-adhesive silicone elastomer materials that have satisfactory adhesion but do not require priming of the surface.

[0006] Although high-energy treatments eliminate the need for curing wet chemical primers, they generally require special capital equipment and assembly processes to be carried out safely for pretreatment.

[0007] For example, it may be desirable to overmold, coat, print, dispense, or otherwise apply a curable silicone elastomer composition onto other components (or substrates) made of different or the same materials. In many cases, these substrates include organic polymer-based thermoplastics such as polyesters, polyamides, polyimides, acrylics, styrenics, polyphthalamides, polycarbonates. In other cases, the substrates include thermosetting resins such as epoxy-based or urethane- or urea-based polymers or composites such as FR-4 substrates (FR-4 is a composite of a woven fiberglass cloth with a flame-retardant epoxy resin binder). For example, a silicone gasket can be molded onto a thermoplastic housing made of polyamide or polyester. Also, a wearable electronic device can be obtained by overmolding a hard thermoplastic such as polycarbonate with a soft layer or component made of liquid silicone rubber. Other examples include airbag fabrics such as polyamide or polyester coated with a silicone elastomer. Organic substrates on which the silicone elastomer composition can be cured include, for example, polyesters such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyamides (PA) such as nylon 6,6 (PA66) and nylon 6,10, polycarbonates (PC) such as bisphenol A polycarbonate, while being able to demold well from a metal mold during injection molding. In other embodiments, the curable silicone composition can be applied onto inorganic substrates (e.g., metals, glasses, or ceramics), onto organic substrates (e.g., the thermoplastics and resins listed previously), and onto cellulose substrates (e.g., paper, wood, 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. In the case of bonding to a polyamide or polyester fabric, even self-adhesive silicone elastomer compositions generally require the fabric to be plasma or corona treated to exhibit good adhesion and scrub resistance.

[0008] In another alternative proposal, it has been suggested to incorporate a hydrosilylation-curable silicone elastomer crosslinker, such as an organohydrogenpolysiloxane, into a polycarbonate substrate. However, it has been found that such methods have a negative effect on the physical properties of the polycarbonate itself, thus inhibiting the resin from exhibiting its own properties. The physical bonding method leaves the possibility that the two segments can be detached by physical forces.

[0009] Using a silicone elastomer is a preferred alternative as it can confer better productivity, quality control, and reliability to the component / article, at least in part due to the elimination of the need for using a primer or surface pretreatment.

[0010] However, while these can provide good initial adhesion to various substrates, it has been found that they pose challenges to the durability of the adhesive bond upon long-term exposure to heat and humidity, even for substrates pretreated with plasma.

[0011] The durability of the adhesion between silicone elastomer materials and thermoplastic substrates, organic resin substrates, or thermoplastic and organic resin substrates is very important for the successful use of such combinations, but it remains a technical challenge to provide a composite that has good adhesion to untreated thermoplastics and has aged (heat / humidity) adhesion to various substrates.

[0012] The present disclosure relates to a curable silicone elastomer composition that is capable of achieving adhesion to plastic / thermoplastic / resin material substrates and comprises:

[0013] (A) one or more organopolysiloxanes having at least 2 alkenyl and / or alkynyl groups per molecule and having a viscosity at 25 °C in the range of 1000 mPa·s to 500,000 mPa·s;

[0014] (B) a curing agent, the curing agent comprising

[0015] (B)(i) an organic peroxide free radical initiator; or

[0016] (B)(ii) a hydrosilylation curing catalyst package, which comprises

[0017] (a) an organosilicon compound having at least 2, alternatively at least 3, Si-H groups per molecule; and

[0018] (b) a hydrosilylation catalyst;

[0019] (C) at least one reinforcing filler and optionally one or more non-reinforcing fillers; and

[0020] (D) an additive based on organopolysiloxane, which is optionally selected from an additive based on diphenylpolysiloxane or an additive based on phenylalkylpolysiloxane, alternatively an additive based on phenylalkylpolysiloxane, alternatively an additive based on phenylmethylpolysiloxane, the additive comprising at least one, alternatively at least two, Si-H groups per molecule and at least one, alternatively at least two, epoxide functional groups per molecule.

[0021] Each of the one or more organopolysiloxanes (A) has at least 2 alkenyl and / or alkynyl groups bonded to silicon atoms per molecule, and uses spindles (LV-1-LV-4) and changes the speed (shear rate) according to the polymer viscosity A rotational viscometer having a viscosity at 25 °C of from 1000 mPa·s to 500,000 mPa·s, alternatively having a viscosity at 25 °C of from 1000 mPa·s to 150,000 mPa·s, alternatively having a viscosity at 25 °C of from 1000 mPa·s to 100,000 mPa·s, alternatively having a viscosity at 25 °C of from 1000 mPa·s to 75,000 mPa·s, and all viscosity measurements are carried out at 25 °C unless otherwise specified.

[0022] Examples of alkenyl groups include vinyl, allyl, butenyl, pentenyl, cyclohexenyl and hexenyl groups. These can be side chains or terminal or in two positions, i.e. they can be present on any siloxy unit of the organopolysiloxane (A). Component (A) comprises linear and / or branched organopolysiloxanes which contain a plurality of units of the formula (1)

[0023] R′ a SiO 4-a / 2 (1)

[0024] wherein each R′ can be the same or different and represents a hydrocarbon group having 1 to 18 carbon atoms, a substituted hydrocarbon group having 1 to 18 carbon atoms or a hydrocarbyloxy group having up to 18 carbon atoms, and having an a value of from 1 to 3, preferably from 1.8 to 2.2, on average.

[0025] For the purposes of this application, "substituted" means that one or more hydrogen atoms in the 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 functional groups, amido functional groups and cyano functional groups; sulfur atoms; and groups containing sulfur atoms such as mercapto groups.

[0026] Unless otherwise specified, when R is generally an alkyl group, such as a methyl group, the siloxy unit can be described by shorthand (abbreviated) nomenclature, namely "M", "D", "T" and "Q" (for further teaching on silicone nomenclature, see Walter Noll, Chemistry and Technology of Silicones, dated 1962, Chapter I, pages 1-9). The M unit corresponds to a siloxy unit with a = 3, i.e. R3SiO1 / 2; the D unit corresponds to a siloxy unit with a = 2, i.e. R2SiO 2 / 2 ; the T unit corresponds to a siloxy unit with a = 1, i.e. R1SiO 3 / 2; The Q unit corresponds to a siloxy unit with a = 0, i.e., SiO 4 / 2 .

[0027] Examples of component (constituent) (A) are polydiorganosiloxanes containing alkenyl or alkynyl groups at both ends but usually containing alkenyl groups, and are represented by the general formula (I):

[0028] R′R″R″′SiO-(R″R″′SiO) m -SiOR″′R″R′ (I)

[0029] In formula (I), each R′ is an alkenyl or alkynyl group, but usually an alkenyl group, which usually contains 2 to 10 carbon atoms, such as vinyl, allyl, and 5-hexenyl.

[0030] R″ does not contain an ethylenically unsaturated group. Each R″ can be the same or different and is independently selected from a monovalent saturated hydrocarbon group (which usually contains 1 to 10 carbon atoms) and a monovalent aromatic hydrocarbon group (which usually contains 6 to 12 carbon atoms). R″ can be unsubstituted or substituted by one or more groups (such as halogen atoms) that do not interfere with the curing of the composition of the present invention. R″′ is R′ or R″, and m represents the degree of polymerization suitable for component (constituent) (A) to have a viscosity within the range described below.

[0031] Generally, all R″ and R″′ groups contained in the compound according to formula (I) are methyl groups. Alternatively, at least one R″ and / or R″′ group in the compound according to formula (I) is a methyl group, and the other groups are phenyl or 3,3,3-trifluoropropyl. This preference is based on the availability of the reactants commonly used to prepare polydiorganosiloxanes (component (constituent) (A)) and the desired properties of the cured elastomers prepared from the compositions containing such polydiorganosiloxanes.

[0032] Particularly preferred examples of the group R′ include methyl, ethyl, propyl, butyl, cyclohexyl, phenyl, tolyl groups, chlorine- or fluorine-substituted propyl groups (such as 3,3,3-trifluoropropyl), chlorophenyl, β-(perfluorobutyl)ethyl, or chlorocyclohexyl groups. Preferably, at least some and more preferably substantially all of the groups R′ are methyl groups. Some R′ groups can be phenyl groups or fluorine groups. In an alternative form, the polydiorganosiloxane is mainly a polydialkylsiloxane and / or a polydialkylalkylphenylsiloxane having at least two alkenyl groups per molecule. In another alternative form, the polydiorganosiloxane is mainly a polydimethylsiloxane having at least two alkenyl groups per molecule. They are preferably substantially linear materials capped with siloxy groups of the formula R”3SiO 1 / 2 and

[0033] Each R” is the same or different. It should be understood that the curing rate and physical properties of the curable composition are affected by the structure and functionality of component (A). For example, in some embodiments, it may be advantageous to use a branched, resinous or cyclic organopolysiloxane having a side chain alkenyl group or alkynyl group as part or all of component (A).

[0034] A rotational viscometer that uses a spindle (LV_4) and changes the speed (shear rate) according to the polymer viscosity is generally used to measure the viscosity of the organopolysiloxane (A) at 25 °C, and unless otherwise specified, all viscosity measurements are carried out at 25 °C. Rotational viscometer measures the viscosity of the organopolysiloxane (A) at 25 °C, and unless otherwise specified, all viscosity measurements are carried out at 25 °C.

[0035] Examples of the organopolysiloxane (A) that can be used include a dimethylsiloxane-vinylmethylsiloxane copolymer capped with vinyldimethylsilyloxy, a polydimethylsiloxane capped with vinyldimethylsilyloxy, a dimethylsiloxane-vinylmethylsiloxane copolymer capped with vinylmethylhydroxysilyloxy, and mixtures thereof.

[0036] The organopolysiloxane (A) can be a single polymer or a combination of two or more different polymers.

[0037] The organopolysiloxane (A) is present in the composition in an amount of 10% to 85% by weight, alternatively 20% to 80% by weight, alternatively 20% to 75% by weight, alternatively 30% to 65% by weight based on the total weight of the composition.

[0038] B) Curing agent

[0039] The compositions described herein can be cured with an organic peroxide free radical initiator (B)(i) or a mixture of different types of peroxide catalysts.

[0040] The peroxide free radical initiator (B)(i) can be any of the well-known commercial peroxides used for curing silicone and / or fluorosilicone rubber elastomer compositions. The amount of the organic peroxide used is determined by the nature of the curing process, the organic peroxide used, and the composition used. Generally, the amount of the peroxide free radical initiator (B)(i) used in the compositions described herein is 0.2% to 3% by weight, alternatively 0.2% to 2% by weight in each case based on the weight of the composition.

[0041] Suitable organic peroxides are substituted or unsubstituted dialkyl peroxides, alkyl aryl acyl peroxides, diaryl acyl peroxides, such as benzoyl peroxide and 2,4-dichlorobenzoyl peroxide, di-tert-butyl peroxide, dicumyl peroxide, lauroyl peroxide, tert-butyl cumyl peroxide, bis(tert-butyl peroxyisopropyl)benzene, cyclohexanone peroxide, cumene hydroperoxide, tert-butyl hydroperoxide, bis(tert-butylperoxy)-2,5-dimethylhex-2-yne, 2,4-dimethyl-2,5-bis(tert-butylperoxy)hexane, di-tert-butyl peroxide and 2,5-bis(tert-butylperoxy)-2,5-dimethylhexane.

[0042] Alternatively, the composition can be packaged with a hydrosilylation catalyst and cured in the following form (B)(ii)

[0043] (B)(ii)(a) an organosilicon compound having at least 2, alternatively at least 3 Si-H groups per molecule; and

[0044] (B)(ii)(b) a hydrosilylation catalyst.

[0045] Component (B)(ii)(a) is a crosslinking agent in the form of an organosilicon compound containing at least 2 or 3 silicon-bonded hydrogen atoms per molecule. Component (B)(ii)(a) usually contains 3 or more silicon-bonded hydrogen atoms, so that the hydrogen atoms can react with the unsaturated alkenyl or alkynyl groups of the polymer (A) to form a network structure therewith, and thereby cure the composition. When the polymer (A) has more than (>) 2 alkenyl or alkynyl groups per molecule, some or all of the component (B)(ii)(a) may alternatively have 2 silicon-bonded hydrogen atoms per molecule.

[0046] The structure of the organosilicon compound can be linear, branched, cyclic or resinous. The cyclosilanes and cyclosiloxanes can have 3 to 12 silicon atoms, or 3 to 10 silicon atoms, or 3 to 4 silicon atoms. In non-cyclic polysilanes and polysiloxanes, the hydrogen atoms bonded to silicon can be located at the ends, side-bonded or at both the ends and side-bonded positions.

[0047] Examples of suitable organosilanes can include diphenylsilane, 2-chloroethylsilane, bis[(p-dimethylsilyl)phenyl]ether, 1,4-dimethyldisilylethane, 1,3,5-tris(dimethylsilyl)benzene, 1,3,5-trimethyl-1,3,5-trisilane, poly(methylmethylsilylene)phenyl and poly(methylmethylsilylene)methylene. In some examples, the organohydrogensilane can have the formula HR 1 2Si-R 2 -SiR 1 2H, where R 1 is a C1 to C 10 hydrocarbon group or C1 to C10 a halogen-substituted hydrocarbyl group, and R 2 is a divalent hydrocarbyl group without aliphatic unsaturation and has a formula 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 g H 2g )Ph.

[0048] The molecular configuration of the organopolysiloxane (B)(ii)(a) containing at least 2 or 3 silicon-bonded hydrogen atoms per molecule is not particularly limited, and it can be linear, linearly branched, cyclic or silicone resin-based. Although the molecular weight of this component is not particularly limited, the viscosity is usually 0.001 Pa·s to 50 Pa·s at 25 °C, using the cup / rotor method according to ASTM D1084 Method B, with the rotor most suitable for the viscosity range obtained from the RV or LV range to obtain good miscibility with the polymer (A).

[0049] The silicon-bonded organic groups for component (B)(ii)(a) can 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, with methyl and phenyl groups being preferred.

[0050] The organosilicon compound (B)(ii)(a) containing at least 2 or 3 silicon-bonded hydrogen atoms per molecule is usually added in an amount such that the molar ratio of the total number of silicon-bonded hydrogen atoms in component (B)(ii)(a) to the total number of alkenyl and / or alkynyl groups in the polymer (A) is from 0.5:1 to 20:1. When this ratio is less than 0.5:1, a well-cured composition will not be obtained. When this ratio exceeds 20:1, there is a tendency for the hardness of the cured composition to increase when heated.

[0051] Examples of the organopolysiloxane (B)(ii)(a) containing at least 2 or 3 silicon-bonded hydrogen atoms per molecule include, but are not limited to:

[0052] (a') Trimethylsiloxy-terminated methylhydrogenpolysiloxane,

[0053] (b') Trimethylsiloxy-terminated polydimethylsiloxane-methylhydrogensiloxane,

[0054] (c') Dimethylhydroxysiloxy-terminated dimethylsiloxane-methylhydrogensiloxane copolymer,

[0055] (d’) Dimethylsiloxane-methylhydrogensiloxane cyclic copolymer,

[0056] (e’) Copolymer and / or silicone resin composed of (CH3)2HSiO 1 / 2 units, (CH3)3SiO 1 / 2 units and SiO 4 / 2 units,

[0057] (f’) Copolymer and / or silicone resin composed of (CH3)2HSiO 1 / 2 units and SiO 4 / 2 units,

[0058] (g’) Copolymer and / or silicone resin composed of ((CH3)2HSiO 1 / 2 units, SiO4 / 2 units and (C6H5)3SiO 1 / 2 units, and alternatives in which the methyl group is replaced by a phenyl group or other alkyl group.

[0059] Optionally, the crosslinking agent in component (B)(ii)(a) can be a filler, such as silica treated with one of the above substances.

[0060] Component (B)(ii)(a) can be exemplified by the following compounds: methylhydrogen polysiloxane capped with trimethylsilyloxy groups at both molecular ends; copolymer of methylhydrogen siloxane and dimethylsiloxane capped with trimethylsilyloxy groups at both molecular ends; dimethylsiloxane capped with dimethylhydroxysilyloxy groups at both molecular ends; copolymer of methylhydrogen siloxane and dimethylsiloxane capped with dimethylhydroxysilyloxy groups at both molecular ends; copolymer of methylhydrogen siloxane and methylphenylsiloxane capped with dimethylphenylsilyloxy groups at both molecular ends; cyclic methylhydrogen polysiloxane; copolymer composed of (CH3)2HSiO 1 / 2 siloxane units and SiO 4 / 2 units; copolymer composed of (CH3)2HSiO 1 / 2 siloxane units, (CH3)3SiO 1 / 2 siloxane units and SiO 4 / 2 units, and the aforementioned organopolysiloxane, in which 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.

[0061] The organopolysiloxane crosslinking agent (B)(ii)(a) is usually present in the curable organosilicon elastomer composition in an amount such that the ratio of the number of moles of silicon-bonded hydrogen atoms of component (B)(ii)(a) to the number of moles of alkenyl groups of 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).

[0062] The silicon-bonded hydrogen (Si-H) content of component (B)(ii)(a) is determined by quantitative infrared analysis in accordance with ASTM E168. In this case, when relying on the hydrosilylation 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 (such as vinyl) [V] in the composition and the total weight % of silicon-bonded hydrogen [H] in the composition, and assuming that the molecular weight of hydrogen is 1 and the molecular weight of vinyl is 27, the molar ratio of silicon-bonded hydrogen to vinyl is 27[H] / [V].

[0063] Typically depending on the number of unsaturated groups in component (A) and the number of Si-H groups in component (B)(ii)(a), component (B)(ii)(a) 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 still alternatively 1% to 5% by weight of the total composition.

[0064] Component (B)(ii)(b) 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 such metals. Due to the high activity level of these catalysts in the hydrosilylation reaction, platinum and rhodium compounds are preferred. Component (B)(ii)(b) catalyzes the reaction between the alkenyl (such as vinyl group) of component (A) and the Si-H group of component (B)(ii)(a), thereby generating a crosslinked network when the curable organosilicon elastomer composition cures into its corresponding elastomer.

[0065] The catalyst (B)(ii)(b) can 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.

[0066] Examples of the preferred hydrosilylation catalyst (B)(ii)(b) are platinum-based catalysts such as platinum black, platinum on various solid supports, chloroplatinic acid, alcoholic solutions of chloroplatinic acid, and complexes of chloroplatinic acid with ethylenically unsaturated compounds such as olefins and organosiloxanes containing silicon-bonded ethylenically unsaturated hydrocarbon groups. Soluble platinum compounds that can be used include, for example, platinum-olefin complexes of the formula (PtCl2. olefin)2 and H(PtCl3. olefin), and in this context, olefins having 2 to 8 carbon atoms such as ethylene, propylene, isomers of butene, and isomers of octene, or cycloalkanes having 5 to 7 carbon atoms such as cyclopentene, cyclohexene, and cycloheptene are preferably used. Other soluble platinum catalysts are, for example, platinum-cyclopropane complexes of the formula (PtCl2C3H6)2, reaction products of hexachloroplatinic acid with alcohols, ethers, and aldehydes or mixtures thereof, or reaction products of hexachloroplatinic acid with methylvinylcyclotetrasiloxane in the presence of an ethanol solution of sodium bicarbonate. Platinum catalysts having phosphorus, sulfur, and amine ligands can also be used, such as (Ph3P)2PtCl2; and complexes of platinum with vinylsiloxanes such as symmetric divinyltetramethyldisiloxane.

[0067] Accordingly, specific examples of suitable platinum-based catalysts include

[0068] (i) complexes of chloroplatinic acid with organosiloxanes containing ethylenically unsaturated hydrocarbon groups as described in US 3,419,593;

[0069] (ii) chloroplatinic acid in the form of the hexahydrate or the anhydrous form;

[0070] (iii) platinum-containing catalysts obtained by a method comprising the step of reacting chloroplatinic acid with an aliphatic unsaturated organosilicon compound such as divinyltetramethyldisiloxane;

[0071] (iv) olefin-platinum-silyl complexes as described in U.S. Patent 6,605,734 such as (COD)Pt(SiMeCl2)2, where "CO" is 1,5-cyclooctadiene; and / or

[0072] (v) Karstedt catalysts, platinum divinyltetramethyldisiloxane complexes that are usually about 1 wt% platinum in a solvent such as toluene. These are described in US3,715,334 and US3,814,730.

[0073] The hydrosilylation catalyst (B)(ii)(b) of the hydrosilylation-curable organosilicon elastomer composition used is present in the total composition in a catalytic amount, that is, an amount or quantity sufficient to catalyze the addition / hydrosilylation reaction and cure the composition into an elastomeric material under the desired conditions. Different amounts of the hydrosilylation catalyst (B)(ii)(b) can be used to customize the reaction rate and curing kinetics. Based on the weight of the polymer (A) and the filler (C) of the composition, the catalytic amount of the hydrosilylation catalyst (B)(ii)(b) is generally between 0.01 ppm and 10,000 parts by weight per million parts (ppm) of platinum group metals; alternatively between 0.01 ppm and 5000 ppm; alternatively between 0.01 ppm and 3,000 ppm and alternatively between 0.01 ppm and 1,000 ppm. In a specific embodiment, based on the weight of the composition, the catalytic amount of the catalyst can be in the range of 0.01 ppm to 1,000 ppm, or 0.01 ppm to 750 ppm, or 0.01 ppm to 500 ppm and or 0.01 ppm to 100 ppm of metal. This range can relate only to the metal content within the catalyst or to the whole of the catalyst as detailed (including its ligands), but typically these ranges relate only to the metal content within the catalyst. The catalyst can be added as a single substance or as a mixture of two or more different substances. Generally, depending on the form / concentration in which the catalyst package is provided, the amount of the catalyst present will be in an amount of 0.001% to 3.0% by weight of the composition.

[0074] Component (C) is a combination of one or more subdivided reinforcing fillers optionally with one or more and / or non-reinforcing fillers.

[0075] The reinforcing fillers of component (C) can be exemplified by subdivided pyrogenic silica and / or subdivided precipitated silica, colloidal silica and / or suitable organosilicon resins.

[0076] Precipitated silica, pyrogenic silica and / or colloidal silica are particularly preferred because of their relatively high surface area (usually at least 50 m2 / g (BET method according to ISO 9277:2010)). Typically, fillers with a surface area of 50 to 450 m 2 / g (BET method according to ISO 9277:2010), alternatively 50 to 300 m 2 / g (BET method according to ISO9277:2010) are used. All these types of silica are commercially available.

[0077] When the reinforcing filler (C) has natural hydrophilicity (such as untreated silica filler), it is usually treated with a treating agent to impart hydrophobicity thereto. These surface-modified reinforcing fillers (C) do not agglomerate and can be uniformly incorporated into the polydiorganosiloxane polymer (A) described below because the surface treatment makes the filler easy to be wetted by the polydiorganosiloxane polymer (A).

[0078] Generally, any low-molecular-weight organosilicon compound disclosed in the art and applicable to preventing the wrinkling of the organosiloxane composition during processing can be used to surface-treat the reinforcing filler (C). For example, organosilanes, polydiorganosiloxanes or organosilazanes, such as hexyl disilazane, short-chain siloxane diols, to impart hydrophobicity to the filler and thus make it easier to handle and obtain a homogeneous mixture with other ingredients (components). Specific examples include, but are not limited to, silanol-terminated trifluoropropylmethylsiloxane, silanol-terminated vinylmethyl (ViMe) siloxane, silanol-terminated MePh siloxane, liquid hydroxy-dimethyl-terminated polydiorganosiloxane having an average of 2 to 20 repeating units of diorganosiloxane per molecule, hydroxy-dimethyl-terminated phenylmethylsiloxane, hexaorganodisiloxanes such as hexamethyldisiloxane, divinyltetramethyldisiloxane; hexaorganodisilazanes, such as hexamethyldisilazane (HMDZ), divinyltetramethyldisilazane and tetramethyldi(trifluoropropyl)disilazane; hydroxy-dimethyl-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 a silica treating agent as a processing aid.

[0079] The surface treatment can be carried out before introducing the composition or in situ (i.e., in the presence of at least a part of the other ingredients (components) of the present composition, by blending these ingredients together at room temperature or higher temperature until the filler is completely treated). Generally, the untreated reinforcing filler (C) is treated in situ with a treating agent in the presence of the polydiorganosiloxane polymer (A), which results in the preparation of an organosilicon elastomer matrix material that can then be mixed with other ingredients (components).

[0080] Based on the weight % of the solids content of the composition, the amount of reinforcing filler (C) is from 5.0% to 40% by weight of the solids content of the composition, alternatively from 7.5% to 35% by weight of the solids content of the composition, alternatively from 10.0% to 35% by weight. Thus, the amount of reinforcing filler (C), such as divided silica and / or silicone resin, can be, for example, from 2.0% to 20% by weight of the total composition, alternatively from 2.5% to 15% by weight of the total composition. In some cases, based on the weight of the total composition, the amount of reinforcing filler can be from 5.0% to 15% by weight.

[0081] Non-reinforcing fillers may optionally be included in component (C) herein. These non-reinforcing fillers can include, for example, ground quartz, calcium carbonate, diatomaceous earth, barium sulfate, iron oxide, titanium dioxide, and carbon black, talc, wollastonite, bauxite, (anhydrous) calcium sulfate, gypsum, calcium sulfate, magnesium carbonate, clays such as kaolin, aluminum hydroxide, magnesium hydroxide (brucite), graphite, copper carbonate such as malachite, nickel carbonate such as zarachite, barium carbonate such as witherite, and / or strontium carbonate such as strontianite.

[0082] Other non-reinforcing fillers can include alumina, silicates selected from: olivines; garnets; aluminosilicates; cyclosilicates; inosilicates; and phyllosilicates. Olivines include silicate minerals such as, but not limited to, forsterite and Mg2SiO4. Garnets include ground silicate minerals such as, but not limited to, pyrope; Mg3Al2Si3O 12 ; grossular; and Ca2Al2Si3O 12 . Aluminosilicates include ground 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[Si4AlO 18 . Inosilicates include ground silicate minerals such as, but not limited to, wollastonite and Ca[SiO3]. Phyllosilicates can alternatively or additionally be used as non-reinforcing fillers, where suitable classes include silicate minerals such as, but not limited to, mica; K2AI 14 [Si6Al2O 20 (OH)4; pyrophyllite; Al4[Si8O 20 (OH)4; talc; Mg6[Si8O 20 (OH)4; serpentine, such as asbestos; kaolinite; Al4[Si4O 10(OH)8; and vermiculite. In an alternative form, the filler will be selected from one or more of the following: fumed silica, precipitated silica, calcium carbonate, talc, mica, quartz, and alumina.

[0083] As previously indicated, component (D) as described above can be selected from additives based on diphenylpolysiloxane or additives based on phenylalkylpolysiloxane, alternatively additives based on phenylalkylpolysiloxane, alternatively additives based on phenylmethylpolysiloxane, which additives contain at least one, alternatively at least one Si-H group per molecule and at least one, alternatively at least two epoxide functional groups per molecule.

[0084] In one embodiment, the organopolysiloxane-based additive, alternatively the phenylalkylpolysiloxane-based additive, alternatively the phenylmethylpolysiloxane-based additive (D) can have the following formula:

[0085] D-O-[Y]-D

[0086] where each D group is a cyclic siloxane of the following structure

[0087] [(O-Si(-)R 3 )(OSiR 3 H) m (OSiR 3 X) a

[0088] where each R 3 group is an alkyl group containing 1 to 6 carbons, and each X is a group containing an epoxide functional group, where m is an integer of at least 1, alternatively 1 to 20, alternatively 1 to 10, alternatively 1 to 6, and a is an integer of at least 1, alternatively 1 to 20, alternatively 1 to 10, alternatively 1 to 6; and preferably m + a is 2 to 20, alternatively 2 to 10, alternatively 2 to 6; and

[0089] [Y] is a linear siloxane group of the structure [SiPhR 3 O] n or [SiPh2O] n ;

[0090] where Ph is a phenyl group and n is an integer from 2 to 20, alternatively 4 to 10, alternatively 5 to 10.

[0091] In the latter case, the Si in the [(O-Si(-)R 3 )] group in the cyclic siloxane is bonded to the linear siloxane group via oxygen. Each R 3 group can be the same or different and is an alkyl group containing 1 to 6 carbons or a substituted alkyl group, alternatively each R3 The groups can be the same or different and are alkyl groups or substituted alkyl groups selected from methyl, ethyl, propyl groups, trifluoropropyl or nonafluorohexyl, alternatively methyl or ethyl groups. Each cyclic siloxane D can have the same or different number of members in the ring, for example having 6 to 20 members in the ring, alternatively having 6 to 16 members in the ring, alternatively having 6 to 14 members in the ring, alternatively having 8 to 12 members in the ring, such as the following cases:

[0092]

[0093] or

[0094]

[0095] Wherein each p in the above formula [2] or [3] can independently be 1, 2 or 3 or greater, and in fact the component (D) can comprise a mixture of one and / or the other of the above, wherein each p in each molecule is 1, 2 or 3 or greater, alternatively 1, 2 or 3. When a mixture is present, preferably, most of the molecules are preferably those in which p is 1. When the component / additive (D) is a mixture, the mixture can additionally comprise, for example, structures similar to the above substances, but wherein the cyclic siloxane D is, for example, a ten-membered ring in which p is 2 or a twelve-membered ring in which p is 3, etc. In one embodiment, the mixture can comprise about 50% to 80% of the molecules in which p is 1, 20% to 49% of the molecules in which p is 2, and the remainder (if any) are the molecules in which p is 3 or greater.

[0096] One example is where [Y] is the epoxy functional group depicted above that is attached via an ether group to the silicon of the (OSiR 3 X) unit in the cyclic siloxane, which can be achieved by reacting an alkenyl glycidyl ether such as allyl glycidyl ether with the Si-H group intermediate to the above cyclic siloxane. For example, when m = 2 and a = 1, the additive (D) can have the following structure, where the cyclic siloxane D is, for example, an eight-membered ring in which p is 1, but it should be understood that the X group can displace any Si-H group on the ring of each cyclic siloxane D and thus does not necessarily have to be in the depicted position:

[0097]

[0098] When the component / additive (D) is a mixture comprising the above substances, the mixture can additionally comprise, for example, structures similar to the above substances, such as a ten-membered ring in which the cyclic siloxane D is, for example, where p is 2 (in formula [2]) and / or a twelve-membered ring in which p is 3 (in formula [2]), etc.

[0099] And when m = 1 and a = 2, the additive (D) can have the following structure, where the cyclic siloxane D is, for example, an eight-membered ring where p is 1, but it should be understood that the X group can replace any Si-H group on the ring of each cyclic siloxane D and thus does not necessarily have to be in the depicted position:

[0100]

[0101] When the component / additive (D) is a mixture containing the above substances, the mixture can additionally contain, for example, structures similar to the above substances, such as where the cyclic siloxane D is, for example, a ten-membered ring where p is 2 (in formula [3]) and / or a twelve-membered ring where p is 3 (in formula [3]), etc.

[0102] In both of the above, n is between 4 and 10, alternatively between 5 and 10.

[0103] The organopolysiloxane-based additive, alternatively the phenylalkylpolysiloxane-based additive, alternatively the phenylmethylpolysiloxane-based additive (which contains at least one, alternatively at least two Si-H groups per molecule and at least one, alternatively at least two epoxy functional groups per molecule) can be prepared by the method described in PCT / US19 / 064350 under the applicant's name, where the starting materials can include a single compound where each p is the same or different or a mixture of compounds where each p is the same or different. Similarly, when the component / additive (D) in this form is a mixture containing the above substances, the mixture can additionally contain, for example, structures similar to the above substances, such as a ten-membered ring where the cyclic siloxane D is and / or a twelve-membered ring where p is 3, etc.

[0104] The amount of the organopolysiloxane-based additive, alternatively the phenylalkylpolysiloxane-based additive, alternatively the phenylmethylpolysiloxane-based additive (D) is usually 0.01% to 25% by weight based on the total weight of the composition, or 0.05% to 5% by weight based on the total weight of the composition, and most commonly 0.25% to 4% by weight. In some cases where the component (D) carries more than 2 SiH groups per molecule, the component (D) can also be used to partially fulfill the role of the SiH component of the component (B). In such cases, those skilled in the art will understand that a larger percentage of the component (D) can be used.

[0105] Depending on the intended use of the curable silicone elastomer composition, optional additives may be present in the composition. Examples include one or more cure inhibitors, vinylated silicone gums, dimethylvinylpolydiorganosiloxanes having a viscosity at 25 °C of 10 mPa·s to 750 mPa·s, mold release agents, adhesion catalysts, peroxides, and / or pigments. Other additives may include conductive fillers, heat conductive fillers, pot life extenders, flame retardants, lubricants, mold release agents, UV light stabilizers, fungicides, wetting agents, heat stabilizers, chain extenders, compression set additives, and plasticizers, etc.

[0106] When needed, cure inhibitors are used to prevent or delay the addition reaction curing process, especially during storage. Optional addition reaction inhibitors for platinum-based catalysts are well known in the art and include hydrazine, triazoles, phosphines, thiols, organic nitrogen compounds, alkynols, methanesilylated alkynols, maleates, fumarates, ethylenically or aromatically unsaturated amides, ethylenically unsaturated isocyanates, vinyl siloxanes, unsaturated hydrocarbon monoesters and diesters, conjugated enyne, hydroperoxides, nitriles, and diaziridines. Vinyl-substituted siloxanes as described in US3989667 can be used, with cyclic methylvinylsiloxanes being preferred.

[0107] A class of known hydrosilylation inhibitors includes the acetylenic compounds disclosed in US3445420. Alkynols such as 2-methyl-3-butyn-2-ol constitute a preferred class of inhibitors, which will inhibit the activity of platinum-containing catalysts at 25 °C. Compositions containing these inhibitors generally need to be heated at a temperature of 70 °C or above in order to cure at an achievable rate.

[0108] Examples of alkynols and their derivatives include 1-ethynyl-1-cyclohexanol (ETCH), 2-methyl-3-butyn-2-ol, 3-butyn-1-ol, 3-butyn-2-ol, propargyl alcohol, 1-phenyl-2-propyn-1-ol, 3,5-dimethyl-1-hexyn-3-ol, 1-ethynylcyclopentanol, 3-methyl-1-pentene-4-yn-3-ol, and mixtures thereof. Alkynol derivatives may include those compounds having at least one silicon atom.

[0109] When present, an inhibitor concentration as low as 1 mole of inhibitor / mole of catalyst metal will, in some cases, impart satisfactory storage stability and cure rate. In other cases, an inhibitor concentration of up to 500 moles of inhibitor / mole of catalyst metal is required. The optimal concentration of a given inhibitor in a given composition can be readily determined by routine experimentation. Depending on the concentration and form in which the selected inhibitor is provided / commercially available, when present in the composition, the inhibitor is generally present in an amount of 0.0125% to 10% by weight of the composition.

[0110] If deemed necessary, the composition may additionally contain a vinylated silicone gum. Such gums generally have a structure similar to that of component A, and dimethylvinyl end groups may be present in the polydimethylsiloxane polymer chain, but there may be a combination of vinyl and methyl groups along the length of the polymer chain. For these polymers, the main differences are the chain length and the subsequent viscosity relative to component (A). Generally, gums of this type have a viscosity of 1,000,000 mPa·s at 25 °C, usually significantly greater. However, since it is difficult to measure viscosities above these values, gums tend to be described in terms of their Williams plasticity value according to ASTM D-926-08 rather than by viscosity. According to ASTM D-926-08, gums of the type described herein typically have a Williams plasticity of 30 mm / 100, alternatively at least 50 mm / 100, alternatively at least 100 mm / 100, alternatively in the range of 100 mm / 100 to 350 mm / 100.

[0111] Dimethylvinylpolydiorganosiloxanes having a viscosity of 10 mPa·s to 750 mPa·s at 25 °C. Such dimethylvinylpolydiorganosiloxanes generally have a structure similar to that of component (A), and dimethylvinyl end groups may be present in the polydimethylsiloxane polymer chain, but there may be a combination of vinyl and methyl groups along the length of the polymer chain. For these polymers, the main differences are the chain length and the subsequent viscosity relative to component (A). Polymers of this type have a zero-shear viscosity of 10 mPa·s to 750 mPa·s at 25 °C. The zero-shear viscosity is obtained by extrapolating the value obtained at a low shear rate to zero, where the viscosity-shear rate curve is independent of the rate, which is a value independent of the test method. The zero-shear viscosity of a substance at 25 °C is typically obtained using a rheometer or viscometer such as a rotational viscometer that utilizes spindles (LV-1 to LV-4) and adjusts the speed (shear rate) according to the polymer viscosity. to obtain.

[0112] Examples of conductive fillers include metal particles, metal oxide particles, metal-coated metal particles (such as silver-plated nickel), metal-coated non-metallic core particles (such as silver-plated talc or mica or quartz), and combinations thereof. The metal particles may be in the form of powders, flakes, or filaments, as well as mixtures or derivatives thereof.

[0113] Examples of heat-conductive fillers include boron nitride, alumina, metal oxides (such as zinc oxide, magnesium oxide, and alumina), graphite, diamond, and mixtures or derivatives thereof.

[0114] Examples of chain extenders include linear organopolysiloxanes having 2 hydrogen groups bonded to silicon at the terminal positions. Such chain extenders are different from the crosslinking agents in component (B)(ii)(a) - organopolysiloxanes having at least 2 or 3 silicon-bonded hydrogen atoms per molecule. Examples of chain extenders include, but are not limited to, disiloxanes or low molecular weight polyorganosiloxanes having two silicon-bonded hydrogen atoms at the terminal positions. Chain extenders typically react with the alkenyl groups of polymer (A) to link together two or more molecules of polymer (A) and increase its effective molecular weight as well as the distance between potential crosslinking sites.

[0115] Disiloxanes are typically represented by the general formula (HR a 2Si)2O. When the chain extender is a polyorganosiloxane, it has terminal units of the general formula HR a 2SiO1 / 2 and non-terminal units of the formula Rb2SiO. In these formulas, Ra and Rb each represent an unsubstituted or substituted monovalent hydrocarbon group that does not contain ethylenic unsaturation and has a fluorine content, including but not limited to alkyl groups having 1 to 10 carbon atoms, substituted alkyl groups having 1 to 10 carbon atoms (such as chloromethyl), cycloalkyl groups having 3 to 10 carbon atoms, aryl groups having 6 to 10 carbon atoms, alkaryl groups having 7 to 10 carbon atoms (such as tolyl and xylyl), and aralkyl groups having 7 to 10 carbon atoms (such as benzyl).

[0116] Other examples of chain extenders include tetramethyldihydrodisiloxane or dimethyl hydrogen-terminated polydimethylsiloxane.

[0117] The chain extender can be added in an amount based on 1 part by weight to 10 parts by weight, typically 1 part / 100 parts to 10 parts / 100 parts of the polymer (A) in combination with the polymer (A).

[0118] Optionally, an adhesion promoter can be present in the composition. Any suitable one or more adhesion promoters can be utilized. These adhesion promoters can comprise one or more alkoxysilanes containing methacrylic groups or acrylic groups and / or one or more alkoxysilanes containing epoxy groups and optionally one or more condensation catalysts or consist of them, and the condensation catalyst, when present, is used to activate and / or accelerate the reaction of the adhesion promoter.

[0119] Examples of alkoxysilanes containing a methacrylic group or an acrylic group are such as methacryloxymethyl-trimethoxysilane, 3-methacryloxypropyl-trimethoxysilane, 3-methacryloxypropyl-methyldimethoxysilane, 3-methacryloxypropyl-dimethylmethoxysilane, 3-methacryloxypropyl-triethoxysilane, 3-methacryloxypropyl-methyldiethoxysilane, 3-methacryloxyisobutyl-trimethoxysilane, or similar methacryloxy-substituted alkoxysilanes; 3-acryloxypropyl-trimethoxysilane, 3-acryloxypropyl-methyldimethoxysilane, 3-acryloxypropyl-dimethyl-methoxysilane, 3-acryloxypropyl-triethoxysilane, or similar acryloxy-substituted alkyl-containing alkoxysilanes.

[0120] Examples of epoxy group-containing alkoxysilanes that can be used as adhesion promoters can include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 4-glycidoxybutyltrimethoxysilane, 5,6-epoxyhexyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, or 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane.

[0121] Adhesion catalysts, i.e., the above-mentioned condensation catalysts for activating and / or accelerating the reaction of adhesion promoters, can also be utilized. Such condensation catalysts can be selected from organometallic catalysts, including titanates, such as tetrapropoxytitanate; zirconates, organoaluminum chelates, titanium chelates, and / or zirconium chelates.

[0122] For example, catalysts based on titanates and zirconates can include compounds according to the general formula Ti[OR 5 4 or Zr[OR 5 4, where each R5 can be the same or different and represents a monovalent primary aliphatic hydrocarbon group, secondary aliphatic hydrocarbon group, or tertiary aliphatic hydrocarbon group, which can be straight-chain or branched-chain, containing 1 to 20 carbon atoms, alternatively 1 to 10 carbon atoms. Optionally, the titanate or zirconate can contain partially unsaturated groups. Preferred examples of R5 include, but are not limited to, methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, and branched secondary alkyl groups such as 2,4-dimethyl-3-pentyl. Preferably, when each R 5 is the same, R 5is an isopropyl, branched secondary alkyl group or a tertiary alkyl group, especially tert-butyl. Specific examples include, but are not limited to, zirconium tetrapropoxide and zirconium tetrabutyrate, tetraisopropyl zirconate, zirconium(IV) acetylacetonate (sometimes called zirconium AcAc), zirconium(IV) hexafluoroacetylacetonate, zirconium(IV) trifluoroacetylacetonate, zirconium tetra(ethyltrifluoroacetylacetonate), zirconium tetra(2,2,6,6-tetramethyl-heptanethiosulfate), dibutoxy bis(ethylpyruvate) zirconium(IV), tributoxy acetoacetic acid zirconium, butoxy acetoacetylpyruvic acid bis(ethylacetoacetate) zirconium, butoxy acetylpyruvic acid bis(ethylacetoacetate) zirconium, diisopropoxy bis(2,2,6,6-tetramethylheptanethiosulfate) zirconium or similar zirconium complexes having a β-diketone (including its alkyl-substituted and fluorine-substituted forms) as a ligand. Also included are the titanate equivalents of the above zirconates.

[0123] Suitable aluminum-based condensation catalysts may include one or more of Al(OC3H7)3, Al(OC3H7)2(CH3COCH2COC 12 H 25 ), Al(OC3H7)2(OCOCH3), aluminum acetylacetonate and Al(OC3H7)2(OCOC 12 H 25 ).

[0124] If deemed necessary and / or advantageous, the adhesion promoter may also include other components, such as other silane coupling agents, organic compounds containing two or more acrylate groups and / or reactive siloxanes.

[0125] Examples of adhesion promoters include silane coupling agents such as methyltrimethoxysilane, vinyltrimethoxysilane, allyltrimethoxysilane, 1,6-bis(trimethylsilyl)hexane, 3-methacryloxypropyltrimethoxysilane and / or glycidoxypropyltrimethoxysilane.

[0126] Examples of organic compounds containing two or more acrylate groups include, for example, diacrylates such as diacrylate C 4-20 alkanediol esters such as hexanediol diacrylate, heptanediol diacrylate, octanediol diacrylate, nonanediol diacrylate and / or undecanediol diacrylate and / or pentaerythritol tetraacrylate.

[0127] Examples of reactive siloxanes include siloxanes such as hydroxy-terminated dimethyl-methylvinylsiloxane, trimethylsilyloxy-terminated methylhydrogensiloxane, which optionally contain one or more perfluoroalkyl chains such as trifluoropropyl or perfluorobutylethyl side chains in various cases. Generally, such siloxanes have a viscosity of 0.001 Pa·s to 0.1 Pa·s at 25 °C, alternatively a viscosity of 0.001 Pa·s to 0.05 Pa·s at 25 °C.

[0128] When present, the adhesion promoter is generally present in the composition in a total amount of about 0.1 wt% to 6 wt% of the composition; alternatively 0.1 wt% to 4 wt% of the composition.

[0129] Examples of flame retardants include aluminum trihydroxide, magnesium hydroxide, magnesium silicate, chlorinated paraffin, chlorinated paraffin, hexabromocyclododecane, triphenyl phosphate, dimethyl methylphosphonate, tris(2,3-dibromopropyl) phosphate (tribromoneopentyl phosphate), and mixtures or derivatives thereof.

[0130] Examples of pigments include iron oxide, carbon black, and mixtures or derivatives thereof.

[0131] Examples of lubricants include tetrafluoroethylene, resin powder, graphite, fluorinated graphite, talc, boron nitride, fluorinated oil, silicone oil, molybdenum disulfide, and mixtures or derivatives thereof.

[0132] Other additives include silicone fluids such as trimethylsilyl or OH-terminated siloxanes. Such trimethylsilyloxy or OH-terminated polydimethylsiloxanes generally have a viscosity of less than (<) 150 mPa·s at 25 °C. When present, such silicone fluids may be present in the curable silicone elastomer composition in an amount in the range of 0.1 wt% to 5 wt% based on the total weight of the composition.

[0133] The curable silicone elastomer composition may comprise:

[0134] A curable silicone elastomer composition, which can achieve significant adhesion to a thermoplastic substrate, to an organic resin substrate or to the surface of a thermoplastic and an organic resin substrate and comprises:

[0135] Component A

[0136] 10 wt% to 85 wt% based on the total weight of the composition, alternatively 20 wt% to 80 wt% based on the total weight of the composition, alternatively 20 wt% to 75 wt% based on the total weight of the composition, alternatively 30 wt% to 65 wt% based on the total weight of the composition.

[0137] When component (B) is (B)(i), the amount of the organic peroxide present can be 0.2% to 3% by weight, alternatively 0.2% to 2% by weight, in each case based on the weight of the composition.

[0138] Alternatively, when component (B) is (B)(ii), component (B)(ii)(a): an organopolysiloxane having at least 2 or 3 silicon-bonded hydrogen atoms per molecule, and the amount of this component is 0.1% - 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 still alternatively 1% to 5% by weight of the total composition;

[0139] Component (B)(ii)(b): at least one hydrosilylation catalyst, and the amount of this component is 0.01% - 10% by weight of the total composition, alternatively 0.01% to 5% by weight of the total composition, and still alternatively 0.05% to 2% by weight of the total composition;

[0140] Component (C): at least one reinforcing filler and optionally one or more non-reinforcing fillers, and the amount of this component is 1% to 80% by weight based on the total weight of the composition, alternatively 1% to 50% by weight based on the total weight of the composition, alternatively 5% to 50% by weight based on the total weight of the composition, and still alternatively 8% to 30% by weight based on the total weight of the composition;

[0141] The present disclosure is intended to include any combination among the above combinations, provided that the total composition percentages of components (A) to (C) and any optional additives constitute 100% by weight based on the weight of the composition. The above composition excluding component (D) is 100% by weight. Component (D) is added in an amount calculated based on the remaining part of the composition being 100%.

[0142] When curing via hydrosilylation, it is important to store the catalyst (B)(ii)(b) separately from the crosslinking agent (B)(ii)(a) to prevent premature curing during storage. Typically, the catalyst (B)(ii)(b) is included in the part A composition, and the crosslinking agent (B)(ii)(a) and any optional inhibitor are stored in the part B composition. Similarly, when the hydrosilylatable component D should be stored separately from the catalyst (B)(ii)(b), the given component (D) contains multiple Si-H groups. Thus, in the case of a hydrosilylatable composition, generally, the crosslinking agent (B)(ii)(a), component D, and any inhibitor used are all included in the part B composition.

[0143] Optional additives (excluding inhibitors) can be in either part (A) or part (B) or in both parts. They can also be added to the final mixture after parts (A) and (B) have been combined.

[0144] In one embodiment, a method for preparing an article or a composite component of an article is provided, the method comprising:

[0145] a) forming a mixture of the curable silicone elastomer composition described herein, and

[0146] b) optionally applying the mixture to the surface of a substrate after the substrate has been surface-treated, for example, by plasma, corona, and / or UV-C;

[0147] c) curing the mixture at a temperature of 80 °C to 250 °C.

[0148] In step (a), when the composition is stored in multiple parts before use, the different parts are combined and uniformly mixed, followed by an optional subsequent step of adding any additional additives as may be required for the end use of the composition.

[0149] The substrate can be any suitable thermoplastic or organic resin substrate. Examples of substrates include acrylonitrile-butadiene-styrene, polyphenylene / styrene blend, polystyrene, polycarbonate (PC), polyurethane, styrene resin, polyethylene, polypropylene, acrylic, polymethacrylic, polyacrylamide, polyester, polyethylene terephthalate, polybutylene terephthalate (PBT), polyphenylene ether, polyphenylene sulfide, polysulfone, nylon, polyamide (PA), blend of polyamide resin and syndiotactic polystyrene, polyimide, fluoropolymer, and liquid crystal resin, polyetherimide without resin. Phenolic resin, epoxy resin, urea resin, melamine resin, alkyd resin, acrylonitrile-butadiene-styrene, styrene-modified poly(phenylene ether), poly(phenylene sulfide), vinyl ester, or polyphthalamide, and combinations thereof. Other substrates can include, for example, cellulose and fabric / textiles, such as on cotton or other natural and synthetic fiber clothes. If desired, any of the above can be activated, for example, by plasma, corona, or UV-C. Generally, when the composition is not of the self-adhesive type, the compositions herein can adhere to metal substrates, such as silicon, aluminum, stainless steel alloy, titanium, copper, nickel, silver, gold, and combinations thereof.

[0150] The uniform mixing of the components of the curable silicone elastomer composition of the present invention can be achieved by using suitable mixing devices such as a kneading mixer, a Z-blade mixer, a two-roll mill (mill), a three-roll mill, It is carried out using a Rheomix OS Lab mixer, a single-screw extruder, a twin-screw extruder, etc. Optionally, a high-speed mixer such as those sold by Hauschild and designated as DC 150.1FV, DAC 400FVZ or DAC 600FVZ can be used.

[0151] The curable organosilicon elastomer composition can be processed (or cured) by injection molding, compression molding, extrusion molding, transfer molding, pressure vulcanization, calendering.

[0152] Curing can be carried out, for example, in a mold to form a molded organosilicon article adhered to, for example, a polycarbonate substrate. The curable organosilicon elastomer composition can be injection molded, for example, to form an article adhered to a polycarbonate 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 curing in the presence of a heat-sensitive substrate, the curable organosilicon elastomer composition as described below is cured under such conditions that mechanical adhesion to the heat-sensitive substrate, etc. can be formed, and more specifically, at a temperature and curing time at which the heat-sensitive substrate does not deform, melt or denature.

[0153] The curable organosilicon elastomer composition can be cured into an organosilicon elastomer article that adheres to a thermoplastic substrate, an organic resin substrate, or a thermoplastic and organic resin substrate, such as a tube, a strip, a solid cord, or a custom profile according to the manufacturer's dimensional specifications.

[0154] The curable organosilicon elastomer composition as described above can be applied to the surface of the substrate by any suitable method such as roll coating, spreading, 3D printing, etc. and cured as described above. After the curable organosilicon elastomer composition is applied to the substrate, the composition is cured at a curing temperature ranging between 80 °C and 250 °C. Such temperature is generally determined by the materials involved. In the case of 3D printing, the 3D printer can be selected from a fused filament fabrication printer, a selective laser sintering printer, a selective laser melting printer, a stereolithography printer, a powder bed (binder jet) printer, a material jet printer, a direct metal laser sintering printer, an electron beam melting printer, a laminated object manufacturing deposition printer, a directed energy deposition printer, a laser powder forming printer, a polymer jet printer, an inkjet printer, a material jet printer, and a syringe extrusion printer.

[0155] The key advantages of the curable organosilicon elastomer composition as described above are:

[0156] ■ Thermal and humidity stability of adhesion (not only initial adhesion)

[0157] ■ Wide range of applications (applicable to PBT, polycarbonate, polyamide)

[0158] ■ Does not affect curing and physical properties

[0159] In one embodiment, provided herein is an article comprising a silicone elastomer cured from a curable silicone elastomer composition as described above, or a silicone elastomer cured from a curable silicone elastomer composition on a rigid or flexible substrate such as a substrate of the type described above.

[0160] In another embodiment, provided is a composite component comprising a silicone elastomer cured from a curable silicone elastomer composition as described above on a rigid or flexible substrate. It should be understood that such composite components include those configurations in which either the substrate or the silicone elastomer serves as an integral component in an article. Examples of substrates as described above.

[0161] In one embodiment, provided is an article or composite component comprising an elastomeric material produced from a curable silicone elastomer composition that adheres to a thermoplastic substrate, an organic resin substrate, or a thermoplastic and organic resin substrate such as those described above.

[0162] 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. A typical method of forming a three-dimensional (3D) article can include multiple steps. For example, the method can include (i) providing a thermoplastic substrate, an organic resin substrate, or a thermoplastic and organic resin substrate. The method can also include (ii) heating the substrate. Additionally, the method can include (iii) printing the curable silicone elastomer composition as described above with a 3D printer to form subsequent layers. Optionally, if one or more additional layers need to be applied, the latter step can be repeated.

[0163] In all of the above cases, examples of such articles or composite components can be found in various industries, including but not limited to automotive applications, medical applications, consumer and industrial applications, and electronic applications. In automotive applications, this can include housings with silicone seals or gaskets, plugs and connectors, components of various sensors, membranes, diaphragms, climate exhaust components, etc. Electronic applications can include mobile phone cover seals, mobile phone accessories, precision electronic devices, electronic switches and switch covers, watches and wristbands, wearable devices (such as face masks), wearable electronic devices, etc.

[0164] The composite part may also be selected from mobile phones, mobile communication devices, game consoles, clocks, image receivers, DVD devices, mobile devices, media devices and MiniDisc (MD) devices, CD devices, and other precision electronic devices, microwave ovens, refrigerators, rice cookers, TVs, thin displays of liquid crystal TVs and plasma TVs, various household appliances, copiers, printers, fax machines, and other office automation (OA) devices, connector seals, spark plug caps, parts of various sensors, and other automotive parts. Examples

[0165] In the following examples, all viscosities were measured using a rotational viscometer that utilizes a spindle (LV-4) and changes the speed (shear rate) according to the polymer viscosity. Unless otherwise specified, all viscosity measurements were obtained at 25 °C. All viscosity measurements were obtained at 25 °C unless otherwise specified.

[0166] Table 1: Compositions for Examples with different additives as shown below

[0167]

[0168] Masterbatch 1 contains 68.7% of dimethylvinyl-terminated dimethylsiloxane (viscosity of about 57,000 MPa·s) and 31.3% of treated silica.

[0169] Four alternative additives were tested.

[0170] Additive 1 (Additive 1) is a mixture of components (D) structures prepared according to the disclosure herein and following the method described in PCT / US19 / 064350, which contains mostly molecules having the following structure (about 51% to 55% for example), where [Y] is a polymethylphenylsiloxane chain, e is 1, d is 0, m is 2, a is 1, and the value of n is the average between 6 and 7, and each cyclic siloxane is an 8-membered ring, and it should be understood that the epoxy group can replace any Si-H group initially located in the ring of each cyclic siloxane, so the main component of the mixture may be but not necessarily the following structure:

[0171]

[0172] The remainder is a mixture of similar molecules, where the cyclic siloxane in the structure is a 10-membered ring (about 40% to 45%) and the remainder (about >0% to 5%). The total adds up to 100%.

[0173] Additive 2 (Additive 2) is also a mixture of components of structure (D) prepared following the method described in PCT / US19 / 064350, which contains mostly molecules (about 51% to 55% for example) with the same structure as Additive 1 but with one difference. m is 1, a is 2, and thus it contains 4 epoxy groups instead of 2 epoxy groups in Additive 1. Therefore, the main component of the mixture can be but is not necessarily the following structure:

[0174]

[0175] The remainder of Additive 4 is a mixture of similar molecules, where the cyclic siloxane in the structure is a 10 - membered ring (about 40% to 45%) and the remainder (about >0% to 5%). The total adds up to 100%.

[0176] The following Comparative Additive 1 (Comparative Additive 1) is a mixture of components of structure (D) prepared according to the method described in US7429636, which contains mostly molecules (about 57.5% to 62% for example) with the following structure: where [Y] is a polydimethylsiloxane chain, d is 1, e is 0, m is 2, a is 1, the number of silicon atoms in the straight chain (n + 2 in the following structure) averages about 7 and each cyclic siloxane is an eight - membered ring. And it should be understood that the X group can replace any Si - H group initially located in the ring of each cyclic siloxane. Therefore, the main component of the mixture can be but is not necessarily the following structure:

[0177]

[0178] The remainder is a mixture of similar molecules, where the cyclic siloxane in the structure is a 10 - membered ring (about 35% to 40%) and the remainder (about >0% to 5%). The total adds up to 100%.

[0179] Another Comparative Additive, Comparative Additive 2, was tested. This is also a mixture of structures, which contains mostly molecules (about 51% to 55% for example) with the following structure, in which [Y] is a polymethylphenylsiloxane chain and the value of n averages between 6 and 7, but it does not have epoxy functionality. Each cyclic siloxane of the main component is an eight - membered ring. Therefore, the main component of the mixture has the following structure, but it does not have epoxy functionality:

[0180]

[0181] The remainder is a mixture of similar molecules, where the cyclic siloxane in the structure is a 10 - membered ring (about 40% to 45%) and the remainder (about >0% to 5%). The total adds up to 100%.

[0182] The corresponding parts A and B of the composition depicted in Table 1 above were mixed in a 1:1 weight ratio using a high-speed mixer, and plates of each sample were prepared and then cured at 150 °C for 5 minutes. The physical properties were then determined as depicted in Table 2 below. The elongation and modulus results were obtained using a DIN S2 die-cured test piece (ASTM D412-98A), and the Shore A hardness was determined in accordance with (ASTM D2240-97).

[0183] Table 2: Physical properties of compositions containing corresponding additives

[0184] Additive 1 Additive 2 Comparison Additive 1 Comparison Additive 2 Elongation(%) 892 1238 742 774 Modulus at 100% elongation (MPa) 0.63 0.36 0.94 0.91 Modulus at 150% elongation (MPa) 0.84 0.48 1.28 1.24 Young's modulus (MPa) 0.5 0.31 0.86 0.82 Tensile strength(MPa) 4.2 3.5 4.8 4.7 Shore Hardness A 33 22 40 39

[0185] Adhesion test

[0186] A nylon 66 laminate having 46x46 thread count and 420 denier was prepared using the composition described above in Table 1 containing the above additives, with the aim of assessing the peak bond strength at tear by peeling the laminate at 180 degrees. Along with the peak bond strength, an estimate of the percentage of cohesive failure was also reported, which was determined by examining the newly exposed surface at the end of the test and estimating the percentage of cohesive failure. The method used was based on ASTM D 413-98, which uses the following different machine speeds, sample widths, and sample thicknesses.

[0187] The fabric was cut along the weft direction (approx. 12 inches) and then along the warp direction (approx. 16 inches) to provide a base sheet (size 12 inches (30.48 cm) × 16 inches (40.64 cm)). All the base sheets used were pre-dried in an oven at 150 °C for one minute. The fabric was then removed and placed on a workbench. The encapsulation mold was aligned such that it was positioned directly across the fabric in the weft direction (the encapsulation used in this study had a depth of 1.16 mm [producing an adhesive line of approximately 1 mm thickness]; all internal dimensions were 10 mm × 10 inches). Parts A and B of the composition were mixed in a 1:1 weight ratio in a speed mixer.

[0188] The encapsulation was filled with the adhesive using a plastic spatula. The encapsulation was removed, and a second corresponding base sheet was placed on top of the sample beads. The beads were then gently wetted using a polystyrene foam roller. The sample was then cured in an oven at 150 °C for 5 minutes.

[0189] As will be seen below, some substrate samples are plasma treated before use. The plasma treatment is carried out after the substrate sheet has been oven treated. For the plasma treated samples, a mark is made on the fabric at the center of the plasma treatment line; although no mark is made at the position where the adhesive will be applied. The bottom sheet of the fabric is plasma treated using a Plasmatreat FG3001 plasma generator; the speed is set to 125 mm / s. The robot coordinates are set to x = 82.24 mm, y = 13.76 mm, z = 117 mm; these coordinates result in a 7 mm gap from the plasma treatment head to the fabric). After treatment, the samples are applied following the above method. The second substrate sheet is plasma treated and the plasma treated surface is applied to the sealant beads. Then the samples are cured as described above.

[0190] The samples are allowed to stand at room temperature for about 20 hours until analysis. Four samples are cut from each specimen, which consist of 10-inch seams. Discard the outer 1-inch (2.54 cm) specimens and cut four 2-inch (5.08 cm) specimens. Then the length of the fabric of each sample is cut to approximately 6 inches (15.24 cm). Then the thickness of each sample is measured. This is done by subtracting the width of two pieces of fabric from the width of the entire sample construction.

[0191] The peak adhesion strength at tear is evaluated by peeling the laminate at 180 degrees. As with the peak adhesion strength, an estimate of the percentage of cohesive failure is also reported, which is determined by examining the newly exposed surface at the end of the test and estimating the percentage of cohesive failure. These are carried out shortly after curing as described above and after 17 days of heat and humidity (H&H) aging at 70 °C and 95% relative humidity.

[0192] In the case of peak load / width, the samples are tested using an MTS Alliance RF / 100 tensile testing machine. The bonded samples are placed in the sample holder, the crosshead speed is set to 8 in / min (200 mm / min), and the peak load / width is determined. The results provided in the following table are the average of four data points.

[0193] In the case of cohesive failure measurement, this is achieved by analyzing the percentage of cohesive failure of the peak load / width of the sample pull. A template containing a 2×10 grid (4 mm×4 mm squares) is placed at the center of the pulled seam, ignoring approximately 5 mm on each side and 2 mm at the top and bottom of the seam. Each square represents 5% of the area. The percentage of cohesive failure of each sample is determined and then the average is taken for each of the four replicates.

[0194] The results for the nylon 66 substrate are depicted in Tables 3a to 3d.

[0195] Table 3a The preparations defined in Table 1 were used in the absence of any additives as described above on a nylon 66 base Reference adhesion test on substrate 。

[0196] Adhesion Promoters deal with H&H Aging Peak load / width (kN / m) Cohesive failure (%) none none no 0.3 0

[0197] Table 3b Adhesion test on nylon 66 substrate using the formulations defined in Table 1 containing Additive 1 。

[0198] Adhesion Promoters deal with H&H Aging Peak load / width (kN / m) Cohesive failure (%) Additive 1 none no 4.2 99 Additive 1 none yes 3.5 100

[0199] It can be seen that adhesion was achieved using Additive 1 without plasma treatment, although the adhesion remained substantially the same after aging.

[0200] Table 3c shows the adhesion test of the formulation containing Additive 2 as defined in Table 1 on a nylon 66 substrate.

[0201] Adhesion Promoters deal with H&H Aging Peak load / width (kN / m) Cohesive failure (%) Additive 2 plasma no 5.2 99 Additive 2 plasma yes 4.9 100

[0202] Example of the present invention: When using SiH and an epoxy-functionalized component / additive (D), adhesion is maintained on the substrate.

[0203] Table 4d Adhesion test on nylon 66 substrate using the formulations defined in Table 1 containing comparative additive 1 。

[0204] Adhesion Promoters deal with H&H Aging Peak load / width (kN / m) Cohesive failure (%) Comparison Additive 1 none no 5.2 99 Comparison Additive 1 none yes 0.2 0 Comparison Additive 1 plasma no 2.5 0

[0205] Comparative example: When using an epoxy-functionalized dimethylsiloxane adhesion promoter, adhesion is not retained on the substrate. Comparative example: When plasma treatment is not used, the adhesion is better.

[0206] Table 4e Adhesion test on nylon 66 substrate using the formulations defined in Table 1 containing comparative additive 2 。

[0207] Adhesion Promoters deal with H&H Aging Peak load / width (kN / m) Cohesive failure (%) Comparison Additive 2 none no 0.9 0 Comparison Additive 2 none yes 0.1 0

[0208] It can be seen that adhesion was not achieved in the absence of epoxy functional groups. Comparative example: When using SiH and an epoxy-functionalized dimethylsiloxane adhesion promoter, adhesion is not retained on the substrate.

[0209] Bonding methods and analysis

[0210] In the following examples shown in Tables 5a and 5b, before applying the curable silicone elastomer composition, the corresponding substrates used were wiped with isopropyl alcohol (IPA) and then air-dried. The curable silicone elastomer composition was applied at a thickness of 25 mils (0.635 mm). Subsequently, the curable silicone elastomer composition was cured in a forced-air oven at 150 °C for 1 hour. Using a razor blade, two vertical lines separated by the approximate width of a spatula blade were etched down through the depth of the cured material across the width of the substrate to the substrate surface. Force was manually applied to the cured elastomeric material between the incisions by a spatula pressed at an angle of approximately 30° relative to the substrate surface. Then the adhesion (or lack thereof) was subjectively evaluated, and the results are provided in Tables 5a and 5b using the following descriptors:

[0211] (-) Poor adhesion = Adhesion failure (separation from the substrate)

[0212] (+) Moderate to good adhesion = Mixed-mode failure [cohesive failure (tearing of the elastomer) and adhesive failure]

[0213] Table 5a. Use of the formulations defined in Table 1 in the absence of any additives and without surface treatment Reference Adhesion Tests Conducted

[0214]

[0215] Cu-Clad FR-4 is a flame-retardant composite of woven fiberglass cloth with an epoxy resin binder.

[0216] Table 5b. Adhesion tests performed using the formulations defined in Table 1 containing Additive 1 or Additive 2

[0217]

[0218] Table 5c. Heat and humidity aging at 85°C and 85% relative humidity (977 hours for 1000 hour test) using Adhesion test of the formulations defined in Table 1 with Additive 1 or Additive 2

[0219]

Claims

1. A curable organosilicon elastomer composition capable of achieving adhesion to a plastic / resin material substrate, and comprising: (A) one or more organopolysiloxanes having at least 2 alkenyl and / or alkynyl groups per molecule and having a viscosity at 25 °C in the range of 1000 mPa·s to 500,000 mPa·s; (B) a curing agent, the curing agent comprising (B)(i) an organic peroxide free radical initiator; or (B)(ii) a hydrosilylation curing catalyst package, the hydrosilylation curing catalyst package comprising a. A silicone compound having at least 2 Si-H groups per molecule; and b. a hydrosilylation catalyst; (C) at least one reinforcing filler and optionally one or more non-reinforcing fillers; and (D) an organopolysiloxane-based additive, the additive comprising at least one Si-H group per molecule and at least one epoxide functional group per molecule, wherein the organopolysiloxane-based additive (D) has the following formula: D-O-[Y]-D where each D group is a cyclic siloxane of the following structure [(O-Si(-)R 3 )(OSiR 3 H) m (OSiR 3 X) a ​ where each R 3 group is an alkyl group having 1 to 6 carbons, and each X is a group containing an epoxide, where m is an integer of at least 1 and a is an integer of at least 1; and [Y] is a linear siloxane group of structure [SiPhR 3 O] n or [SiPh2O] n ; where Ph is a phenyl group and n is an integer from 2 to 20.

2. The curable organosilicon elastomer composition according to claim 1, wherein the organopolysiloxane-based additive (D) has the following formula: D-O-[Y]-D where each D group is a cyclic siloxane of the following structure [(O-Si(-)R 3 )(OSiR 3 H) m (OSiR 3 X) a ​ where each R 3 group is an alkyl group having 1 to 6 carbons and each X is a group containing an epoxide, [Y] is a linear siloxane group of the structure [SiPhR 3 O] n or [SiPh2O] n ; Among them, Ph is a phenyl group and m is 2, a is 1 and the value of n is the average between 4 and 10, or where m is 1, a is 2 and the value of n is the average between 4 and 10.

3. The curable organosilicon elastomer composition according to claim 1 or 2, wherein the organopolysiloxane-based additive (D) is added to the composition in an amount of 0.5% to 5% by weight based on the total composition of the other components.

4. The curable organosilicon elastomer composition according to claim 1 or 2, wherein the composition comprises a curing inhibitor.

5. The curable organosilicon elastomer composition according to claim 1 or 2, the curable organosilicon elastomer composition being stored in at least 2 separate parts before use.

6. A method for preparing an article or a composite part of an article, the method comprising: a) forming a mixture of the curable organosilicon elastomer composition according to claim 1 or 2, and b) applying the mixture to the surface of a substrate; c) curing the mixture at a temperature of 80 °C to 250 °C.

7. The method according to claim 6, wherein the substrate is polycarbonate.

8. An article cured from the curable organosilicon elastomer composition according to claim 1.

9. The article according to claim 8, the article containing an organosilicon elastomer cured from the curable organosilicon elastomer composition according to claim 1 or 2, the curable organosilicon elastomer composition being adhered to a plastic substrate.

10. The article according to claim 8, wherein the article contains a silicone elastomer cured from a curable silicone elastomer composition according to claim 1 or 2, and the curable silicone elastomer composition adheres to a thermoplastic substrate, an organic resin substrate, or a thermoplastic and organic resin substrate.

11. The article according to any one of claims 9 or 10, wherein the article is selected from housings with silicone seals or gaskets, plugs and connectors, components of various sensors, membranes, personal electronic devices, precision electronic devices, electrical switches and switch covers, and wearable electronic devices.

12. A composite component, comprising a silicone elastomer cured from a curable silicone elastomer composition according to any one of claims 1 or 2 on a plastic / resin material substrate.

13. The composite component according to claim 12, wherein the composite component is selected from housings with silicone seals or gaskets, plugs and connectors, membranes, personal electronic devices, precision electronic devices, electrical switches and switch covers, wearable devices, mobile telecommunications devices, gaming machines, clocks, image receivers, DVD devices, MD devices, CD devices, various household appliances, copiers, printers, fax machines, connector seals, spark plug caps, components of various sensors.

14. Use of the composition according to claim 1 or 2 for manufacturing an article, the article comprising a cured elastomeric material made from the composition adhered to a thermoplastic substrate, an organic resin substrate, or a thermoplastic and organic resin substrate; and a method for adhering the composition with improved thermo-humid stability to the thermoplastic or organic resin-based substrate.

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