Silicone composition

Abstract

The present invention discloses an organosilicon composition having a low complex viscosity when mixed, providing high electrical conductivity upon curing and good electrical conductivity retention after thermal aging treatment, the organosilicon composition comprising (A) a conductive filler, (B) a polydiorganosiloxane polymer, (C) a polyorganohydrosiloxane, (D) a hydrosilylation catalyst, (E) a polymer additive, and optionally (F) a hydrosilylation inhibitor.

Description

Technical Field

[0001] The present invention relates to an organosilicon composition and a conductive organosilicon adhesive made from the composition. Background Technology

[0002] Silicone adhesives are used in a variety of applications, such as the automotive, electronics, construction, electrical, and aerospace industries. Due to the inherent insulating properties of silicone resins, silicone compositions require the incorporation of conductive fillers to improve the electrical properties of cured products prepared from them for conductive applications such as conductive adhesives and electromagnetic interference (EMI) shielding materials.

[0003] While increasing the amount of conductive filler can improve the electrical conductivity of silicone adhesives, the resulting highly filled silicone compositions are more expensive and difficult to achieve the desired low complex viscosity. For example, when measured over 2 hours after all components of the silicone composition have been mixed together, the complex viscosity of the formulation at room temperature (23 ± 2 °C) is 350,000 Pa·s or lower. Therefore, there is a continued need for silicone compositions that provide silicone adhesives with improved electrical properties while maintaining a low complex viscosity for ease of processing and application.

[0004] Furthermore, conductive metal fillers tend to oxidize over time and eventually become non-conductive. Silicone adhesives containing such fillers typically exhibit poor electrical stability at high temperatures (e.g., 80°C to 150°C), as indicated by a ten- to one-hundred-fold increase in volume resistivity (VR) after one month of use at 80°C to 125°C. Therefore, reducing the VR change of silicone adhesives after prolonged thermal aging is also challenging.

[0005] It is desirable to discover an organosilicon composition suitable for preparing conductive adhesives without the aforementioned problems. Summary of the Invention

[0006] This invention addresses the problem of finding silicone compositions that do not possess the aforementioned issues. The invention provides a novel silicone composition comprising a conductive filler (A), a polydiorganosiloxane polymer (B), a polyorganohydrosiloxane (C), a hydrosilylation catalyst (D), a specific polymer additive (E), and optionally a hydrosilylation inhibitor (F). This silicone composition has a complex viscosity of no more than 350,000 Pa·s at room temperature (23 ± 2 °C), as measured within 2 hours after mixing all components of the silicone composition. Upon curing, this silicone composition also provides a cured product with improved electrical conductivity, such as a silicone adhesive, as indicated by a lower volume resistivity (VR) compared to a cured product made from a similar silicone composition lacking only the polymer additive (E) (hereinafter “existing silicone compositions”). The silicone compositions of the present invention also provide good conductivity retention after thermal aging treatment; for example, compared with cured products made from existing silicone compositions, the cured products of this silicone composition show less VR change after thermal aging at 125°C for 20 days or longer. These properties were measured according to the test methods described in the Examples section below.

[0007] In a first aspect, the present invention provides an organosilicon composition, which, based on the total weight of the organosilicon composition, comprises:

[0008] (A) 66% to 89% conductive filler;

[0009] (B) 5% to 40% of polydiorganosiloxane polymers of formula (I),

[0010] (R 1 3SiO 1 / 2 )2(R 1 2SiO 2 / 2 ) n (I),

[0011] Each R 1 Independently, it is a monovalent aliphatic hydrocarbon group, n is in the range of 35 to 1,000, and the polyorganosiloxane polymer contains an average of at least two alkenyl groups per molecule;

[0012] (C) Polyorganohydrosiloxanes of Formula (II),

[0013] (R 2 3SiO 1 / 2 )2(R 2 2SiO 2 / 2 ) m (II)

[0014] Each R2 Independently, it is hydrogen or an alkyl group having 1 to 20 carbon atoms, m is in the range of 5 to 200, and the polyorganohydrosiloxane has an average of at least three silicon-bonded hydrogen atoms per molecule;

[0015] (D) Catalyst for hydrosilylation reaction;

[0016] (E) 0.1% to 1.5% of a polymer additive having a molecular weight greater than 2,000 g / mol to 20,000 g / mol, wherein the polymer additive is selected from the group consisting of: polypropylene glycol, alcohol-initiated copolymers of ethylene oxide and propylene oxide, or mixtures thereof; and

[0017] (F) 0% to 0.3% inhibitor of hydrosilylation reaction.

[0018] In a second aspect, the present invention provides a method for preparing the organosilicon composition of the first aspect. The method comprises mixing the conductive filler, the polydiorganosiloxane polymer, the polyorganohydrosiloxane, the hydrosilylation catalyst, the polymer additive, and the hydrosilylation inhibitor (if used).

[0019] In a third aspect, the present invention provides a silicone adhesive comprising a cured product of the silicone composition of the first aspect. Detailed Implementation

[0020] The silicone composition of the present invention comprises one or more conductive fillers as component (A). “Conductive filler” refers to any filler exhibiting an intrinsic resistivity of less than 1 ohm-cm (Ω·cm) at 20°C, as determined by GB / T 351-2019 (National Standard of China for Measurement of Resistivity of Metallic Materials). Conductive fillers typically comprise particles having an outer surface of at least a metal selected from the group consisting of: silver, gold, platinum, palladium, nickel, copper, or alloys thereof. Conductive fillers may include particles composed of: silver, gold, platinum, palladium, nickel, copper, or alloys thereof; preferably, silver. Alternatively, conductive fillers may include particles having only an outer surface composed of silver, gold, platinum, palladium, or alloys thereof; and a core (also referred to as “metal-coated particles”) different from the outer surface. The core of such particles can be any material, conductor, or insulator that supports the outer surface and does not adversely affect the electrical properties of the silicone adhesive (i.e., the cured product of the silicone composition) made from the silicone composition. Examples of such materials used for the core include copper, graphite, aluminum, glass such as solid or hollow glass, mica, nickel, or ceramic fibers. Preferably, the conductive filler comprises silver-coated particles. The conductive filler may include, for example, silver-coated nickel particles, silver-coated aluminum particles, silver-coated copper particles, silver-coated glass particles, or mixtures thereof. As determined by inductively coupled plasma mass spectrometry (ICP-MS), the silver-coated particles typically have a silver content of 1% or more, 2% or more, 3% or more, 4% or more, 5% or more, 6% or more, 7% or more, 8% or more, 9% or more, 10% or more, 11% or more, or even 12% or more, based on the weight of the silver-coated particles, and simultaneously 60% or less, 55% or less, 50% or less, 45% or less, or even 40% or less.

[0021] The conductive fillers used in this invention are typically in powder form and are in the shape of flakes, rods, fibers, or spheres or other irregular shapes. The conductive fillers used in this invention may include fillers prepared by treating the surface of the aforementioned particles with at least one organosilicon compound. Suitable organosilicon compounds include those commonly used to treat silica fillers such as organochlorosilanes, organosiloxanes, organodisilazanes, organoalkoxysilanes, or mixtures thereof. The conductive filler may be a single conductive filler as described above or a mixture of two or more such fillers that differ in at least one of the following properties: composition, surface area, surface treatment, particle size, and particle shape.

[0022] The conductive fillers used in this invention can have a median particle size of 0.5 micrometers (μm) or larger, 1 μm or larger, 5 μm or larger, 10 μm or larger, 15 μm or larger, 20 μm or larger, 25 μm or larger, 30 μm or larger, 35 μm or larger, or even 40 μm or larger, and simultaneously a median particle size of 100 μm or smaller, 90 μm or smaller, 80 μm or smaller, 75 μm or smaller, 70 μm or smaller, 65 μm or smaller, 60 μm or smaller, or even 50 μm or smaller. In this invention, "median particle size" refers to the D50 particle size measured according to the test methods described in the Examples section below.

[0023] Methods for preparing conductive fillers suitable for the organosilicon compositions of the present invention are well known in the art. For example, powders of silver, gold, platinum, or palladium, or alloys thereof, are typically produced by chemical precipitation, electrolytic deposition, or cementation. Sheets of the aforementioned metals are typically produced by grinding or milling metal powders. Particles having only the outer surface of at least one of the aforementioned metals are typically produced by metallizing a suitable core material using methods such as electrolytic deposition, electroless deposition, or vacuum deposition. When the conductive filler is prepared by treating the particle surface with an organosilicon compound, the particles can be treated before mixing with other components of the organosilicon composition, or the particles can be treated in situ during the preparation of the organosilicon composition.

[0024] The conductive filler in the silicone composition of the present invention can be present in an amount that imparts a desired viscosity to the silicone composition and imparts electrical conductivity to the silicone adhesive produced from the silicone composition. As determined by the test methods described in the Examples section below, when measured over 2 hours after all components of the silicone composition are mixed together, the desired complex viscosity of the silicone composition is typically 350,000 Pa·s or less at room temperature (23 ± 2 °C). The concentration of the conductive filler depends on the desired electrical properties, the surface area of ​​the filler, the density of the filler, the shape of the filler particles, the surface treatment of the filler, and the properties of other components in the silicone composition. By weight, based on the total weight of the silicone composition, the conductive filler can be present in amounts of 66% or more, 69% or more, 70% or more, 70% or more, 71% or more, or even 72% or more, and simultaneously in amounts of 89% or less, 88% or less, 87% or less, 86% or less, 85% or less, 84% or less, 83% or less, or even 82% or less.

[0025] The conductive filler used in this invention can be selected from one or a combination of more than one of the following three types of conductive fillers: (a1) silver-coated nickel particles, (a2) silver-coated aluminum particles, and (a3) ​​silver-coated glass particles. For example, based on the total weight of the organosilicon composition, the silver-coated nickel particles (a1) can be present in amounts of 0 or more, 35% or more, 40% or more, 45% or more, 50% or more, or even 55% or more, and simultaneously in amounts of 89% or less, 88% or less, 87% or less, 86% or less, 85% or less, 84% or less, or even 83% or less. By weight, based on the total weight of the silicone composition, the silver-coated aluminum particles (a2) may be present in amounts of 0 or more, 15% or more, 18% or more, 20% or more, 22% or more, 25% or more, or even 27% or more, and simultaneously in amounts of 82% or less, 80% or less, 78% or less, 73% or less, 70% or less, 68% or less, or even 66% or less. By weight, based on the total weight of the silicone composition, the silver-coated glass particles (a3) ​​may be present in amounts of 0 or more, 15% or more, 20% or more, 25% or more, 30% or more, 40% or more, 50% or more, 60% or more, 70% or more, or even 72% or more, and simultaneously in amounts of 82% or less, 80% or less, 78% or less, 76% or less, or even 73% or less.

[0026] The organosilicon composition of the present invention further comprises one or more polydiorganosiloxane polymers as component (B). The polydiorganosiloxane polymers have formula (I).

[0027] (R 1 3SiO 1 / 2 )2(R 1 2SiO 2 / 2 ) n (I)

[0028] Each R 1 Independently, it is a monovalent aliphatic hydrocarbon group, n is in the range of 35 to 1,000, and the polyorganosiloxane polymer contains an average of at least two alkenyl groups per molecule.

[0029] The value of n in equation (I) can be 35 or higher, 50 or higher, 100 or higher, 150 or higher, 200 or higher, 250 or higher, or even 300 or higher, and at the same time 1,000 or lower, 900 or lower, 800 or lower, 700 or lower, 650 or lower, or even 600 or lower.

[0030] Suitable monovalent aliphatic hydrocarbon groups can include alkyl groups and alkenyl groups. "Alkyl" refers to a cyclic, branched, or unbranched saturated monovalent hydrocarbon group. (The last part, "R," appears to be a typographical error and is left untranslated.) 1 The alkyl group typically has 1 to 20 carbon atoms, 1 to 12 carbon atoms, 1 to 10 carbon atoms, 1 to 6 carbon atoms, 1 to 3 carbon atoms, or 1 to 2 carbon atoms. Examples of suitable alkyl groups include methyl, ethyl, propyl (e.g., isopropyl and / or n-propyl), butyl (e.g., isobutyl, n-butyl, tert-butyl, and / or sec-butyl), pentyl (e.g., isopentyl, neopentyl, and / or tert-pentyl), hexyl, heptyl, octyl, nonyl, and decyl, as well as branched alkyl groups having 6 or more carbon atoms; and cycloalkyl groups, such as cyclopentyl and cyclohexyl. A preferred alkyl group is methyl. "Alkenyl" means a branched or unbranched monovalent hydrocarbon group having one or more carbon-carbon double bonds. 1 The alkenyl group typically has 2 to 10 carbon atoms, 2 to 8 carbon atoms, or 2 to 6 carbon atoms. Examples of suitable alkenyl groups include vinyl, allyl, propenyl (e.g., isopropenyl and / or n-propenyl); and butenyl, pentenyl, hexenyl, and heptenyl (including branched and straight-chain isomers having 4 to 7 carbon atoms); and cyclohexenyl. Preferably, the alkenyl group is vinyl. The alkenyl group in the polydiorganosiloxane polymer can be located at the terminal position, the side chain position, or both the terminal and side chain positions. Preferably, at least 50 mol%, 60 mol% or more, 70 mol% or more, or even 80 mol% or more of R 1 The monovalent aliphatic hydrocarbon group represented is methyl. The molar percentage of methyl groups in this document can be determined by nuclear magnetic resonance (NMR) analysis. Polydiorganosiloxane polymers that can be used in this invention may include, for example, ViMe2SiO (Me2SiO). n SiMe₂Vi, ViMe₂SiO (Me₂SiO) 0.98n (MeViSiO) 0.02n SiMe2Vi and Me3SiO (Me2SiO) 0.95n (MeViSiO) 0.05n SiMe3, where Me and Vi represent methyl and vinyl groups, respectively, and n is as defined above.

[0031] Examples of suitable polydiorganosiloxane polymers include b1) dimethylvinylsiloxy-terminated polydimethylsiloxane, b2) dimethylvinylsiloxy-terminated poly(dimethylsiloxane / methylvinylsiloxane), b3) dimethylvinylsiloxy-terminated polymethylvinylsiloxane, b4) trimethylsiloxy-terminated poly(dimethylsiloxane / methylvinylsiloxane), b5) trimethylsiloxy-terminated polymethylvinylsiloxane, b6) dimethylvinylsiloxy-terminated poly(dimethylsiloxane / methylvinylsiloxane), b7) dimethylvinylsiloxy-terminated poly(dimethylsiloxane / methylphenylsiloxane), and b8) dimethylvinylsiloxy-terminated poly(dimethylsiloxane / diphenylsiloxane). (b9) polydimethylsiloxanes capped with phenyl, methyl, or vinyl-siloxy groups, (b10) polydimethylsiloxanes capped with dimethylhexenylsiloxy groups, (b11) poly(dimethylsiloxane / methylhexenylsiloxane) capped with dimethylhexenylsiloxy groups, (b12) poly(methylhexenylsiloxane) capped with dimethylhexenylsiloxy groups, (b13) poly(dimethylsiloxane / methylhexenylsiloxane) capped with trimethylsiloxy groups, (b14) poly(methylhexenylsiloxane) capped with trimethylsiloxy groups, (b15) poly(dimethylsiloxane / methylhexenylsiloxane) capped with dimethylhexenylsiloxy groups, (b16) poly(dimethylsiloxane / methylhexenylsiloxane) capped with dimethylvinylsiloxy groups, or combinations thereof. Preferably, the polydiorganosiloxane polymer is selected from the group consisting of: b1) dimethylvinylsiloxy-terminated polydimethylsiloxane, b2) dimethylvinylsiloxy-terminated poly(dimethylsiloxane / methylvinylsiloxane), or a combination of b1) and b2).

[0032] Polydiorganosiloxane polymers are known in the art and can be prepared by methods such as hydrolysis and condensation of corresponding organohalosilanes or equilibration of cyclic polydiorganosiloxanes.

[0033] Polydiorganosiloxane polymers can be a single polydiorganosiloxane or a mixture containing two or more polydiorganosiloxanes that differ in at least one of the following properties: structure, average molecular weight, siloxane units, and sequence.

[0034] Based on the total weight of the organosilicon composition, the polydiorganosiloxane polymers used in this invention may be present in the organosilicon composition in amounts of 5% or more, 6% or more, 7% or more, 7.5% or more, 9% or more, 10% or more, 12% or more, 15% or more, 18% or more, or even 20% or more, and simultaneously in amounts of 40% or less, 38% or less, 35% or less, 32% or less, 30% or less, 28% or less, or even 25% or less, in the organosilicon composition.

[0035] The organosilicon composition of the present invention comprises one or more polyorganohydrosiloxanes as component (C). The polyorganohydrosiloxanes have formula (II).

[0036] (R 2 3SiO 1 / 2 )2(R 2 2SiO 2 / 2 ) m (II)

[0037] Each R 2 Independently, it is a hydrogen or alkyl group, m is in the range of 5 to 200, and the polyorganohydrosiloxane has an average of at least three silicon-bonded hydrogen atoms (SiH) per molecule. (By R) 2 The alkyl group may have 1 to 20 carbon atoms, 1 to 12 carbon atoms, 1 to 10 carbon atoms, 1 to 6 carbon atoms, 1 to 3 carbon atoms, or 1 to 2 carbon atoms, including, for example, methyl, ethyl, propyl, and butyl.

[0038] The value of m in equation (II) can be 5 or higher, 7 or higher, 10 or higher, 20 or higher, 30 or higher, 40 or higher, or even 50 or higher, and at the same time 200 or lower, 150 or lower, 140 or lower, 130 or lower, 120 or lower, 110 or lower, or even 100 or lower.

[0039] Based on the weight of the polyorganohydrosiloxane, the polyorganohydrosiloxane used in this invention may comprise 0.38% or more, 0.5% or more, 0.6% or more, or even 0.75% or more, and simultaneously 2% or less, 1.9% or less, 1.8% or less, 1.75% or less, 1.7% or less, or even 1.6% or less of silicon-bonded hydrogen atoms. The content of silicon-bonded hydrogen atoms can be determined by NMR analysis.

[0040] Methods for preparing polyorganohydrosiloxanes (such as the hydrolysis and condensation of organohydrohalosilanes) are well known in the art. Examples of suitable polyorganohydrosiloxanes include c1) trimethylsiloxy-terminated poly(dimethyl / methylhydro)siloxanes, c2) trimethylsiloxy-terminated polymethylhydrosiloxanes, c3) dimethylhydrosiloxy-terminated polydimethylsiloxanes, c4) dimethylhydrosiloxy-terminated poly(dimethylsiloxane / methylhydrosiloxane), c5) dimethylhydrosiloxy-terminated polymethylhydrosiloxanes, and c6) poly(dimethylsiloxane / methylhydrosiloxane) essentially composed of H(CH3)2SiO 1 / 2 unit and SiO 4 / 2 Resins composed of units, or combinations thereof.

[0041] The polyorganohydrosiloxane is present in an amount sufficient to provide 0.5 to 10, for example, 0.7 to 8, 0.8 to 7, 0.9 to 6, 1 to 5, or 1.05 to 2, of silicon-bonded hydrogen atoms in the polyorganohydrosiloxane to alkenyl groups in all components of the silicone composition (including alkenyl groups in the polydiorganosiloxane polymer (B) and other components containing alkenyl groups, such as the polyorganosilicate resin (G) described below, if used), which is referred to as the SiH / Vi ratio. Based on the total weight of the silicone composition, the silicone composition typically contains 0.2% or more, 0.3% or more, 0.4% or more, 0.5% or more, and simultaneously 2% or less, 1.8% or less, 1.6% or less, 1.5% or less, or even 1.2% or less of polyorganohydrosiloxane.

[0042] The organosilicon compositions of the present invention include one or more polymeric additives as component (D). The polymeric additives are selected from the group consisting of polypropylene glycol (PPG), alcohol-initiated ethylene oxide and propylene oxide copolymers (hereinafter “alcohol-initiated EO / PO copolymers”), or mixtures thereof.

[0043] The polymer additives used in this invention may have 2 or more, 2.1 or more, 2.5 or more, or even 3 or more per molecule, and simultaneously have an average number of 12 or fewer, 10 or fewer, 8 or fewer, or even 6 or fewer hydroxyl groups per molecule.

[0044] Preferably, the polymer additives that can be used in this invention include one or more alcohol-initiated EO / PO copolymers. The alcohol-initiated EO / PO copolymers can be linear or branched random copolymers.

[0045] The alcohol-initiated EO / PO copolymers that can be used in this invention can have the structure of formula (III):

[0046] (A) z B(III)

[0047] Where A represents HO-(CHR) p -CHR q -O) x -(CH2-CH2-O) y - where x ranges from 8 to 40, y ranges from 1 to 20, and R p and R q Different and selected from hydrogen and -CH3, z is 1 to 12, and B is hydrogen or a monovalent hydrocarbon group, divalent hydrocarbon group or polyvalent hydrocarbon group having 3 to 18 carbon atoms.

[0048] The sequences of the ethylene oxide unit (-CH2CH2-O)-) and the propylene oxide unit (-(CH2CHCH3-O)-) in segment A of formula (III) can be random or can be any type of block configuration orientation such as a monoblock of ethylene oxide unit and a monoblock of propylene oxide unit.

[0049] In equation (III), x and y are the average numbers of propylene oxide units and ethylene oxide units, respectively. The value of x can be 8 to 40, 10 to 35, 15 to 30, or 20 to 28. The value of y can be 1 to 20, 1 to 18, or 1 to 16.

[0050] In equation (III), z can be 1 to 12, 2 to 10, 3 to 8, or 4 to 6.

[0051] In formula (III), the value of (x+y+z) is sufficient to give the alcohol-initiated EO / PO copolymer the molecular weight as described below.

[0052] In formula (III), B may have 3 to 18 carbon atoms, 3 or 12 carbon atoms, 3 to 10 carbon atoms, 3 to 8 carbon atoms, or 4 to 6 carbon atoms.

[0053] When B is a monovalent or divalent hydrocarbon group, formula (III) represents a straight-chain structure. When B is a polyvalent (e.g., trivalent or higher valence) hydrocarbon group, formula (III) represents a branched-chain structure. B can be a group derived from sorbitol, as follows.

[0054]

[0055] Alternatively, B can be a group derived from glycerol,

[0056]

[0057] The alcohol-initiated EO / PO copolymers used in this invention can be prepared from alcohol initiators having 3 or more carbon atoms, 4 or more carbon atoms, 5 or more carbon atoms, or even 6 or more carbon atoms, and typically 18 or fewer carbon atoms, 12 or fewer carbon atoms, 10 or fewer carbon atoms, 8 or fewer carbon atoms, or even 6 or fewer carbon atoms. The alcohol initiator can be a straight-chain or branched alcohol, and preferably a branched alcohol. The alcohol initiator can be a monool, diol, triol, tetraol, pentanol, or hexanol. Preferably, the alcohol initiator is hexanol. Preferably, the alcohol initiator used to prepare the EO / PO copolymer is sorbitol, glycerol, or a mixture thereof. Methods and conditions for preparing the alcohol-initiated EO / PO copolymer are known to those skilled in the art, for example, at temperatures ranging from 20°C to 180°C or from 100°C to 160°C. The preparation of alcohol-initiated EO / PO copolymers can be found, for example, in J. Herzberger et al., “Polymerization of ethylene oxide, propylene oxide, and other alkylene oxides: synthesis, novel polymer architectures, and bioconjugation”, Chemical Reviews, Vol. 116, No. 4, pp. 2170-2243 (2016).

[0058] Based on the weight of the alcohol-initiated EO / PO copolymer, the alcohol-initiated EO / PO copolymer that can be used in this invention may include 50% or more, 52% or more, 55% or more, 58% or more, 60% or more, 62% or more, or even 65% or more, while 99% or less, 98% or less, 97% or less, 96% or less, or even 95% or less of propylene oxide units (also as propylene oxide chains).

[0059] The polymer additives that can be used in this invention have a concentration greater than 2,000 g / mol, for example, 2,100 g / mol or more, 2,200 g / mol or more, 2,300 g / mol or more, 2,500 g / mol or more, 2,600 g / mol or more, 2,700 g / mol or more, 2,800 g / mol or more, 2,900 g / mol or more, 3,000 g / mol or more, 3,200 g / mol or more, 3,500 g / mol or more, 3,800 g / mol or more, 4,000 g / mol or more, 4,500 g / mol or more, 5,000 g / mol or more, 5,500 g / mol or more, 6 ... Molecules of 00 g / mol or more, 6,500 g / mol or more, 7,000 g / mol or more, 7,500 g / mol or more, 8,000 g / mol or more, or even 9,000 g / mol or more, while 20,000 g / mol or less, 19,000 g / mol or less, 18,000 g / mol or less, 17,000 g / mol or less, 16,000 g / mol or less, 15,000 g / mol or less, 14,000 g / mol or less, 13,000 g / mol or less, 12,000 g / mol or less, 11,000 g / mol or less, or even 10,000 g / mol or less. The molecular weights mentioned in this article are exponentially average molecular weights (M). n It is calculated by (56100*f) / OHV, where f represents the average number of hydroxyl groups per molecule of polymer additive (also known as "OH functionality"), and OHV represents the hydroxyl value of polymer additive in mg KOH / g, as determined by ASTM D4274-2011.

[0060] Based on the total weight of the organosilicon composition, the organosilicon composition of the present invention may contain 0.1% or more, 0.12% or more, 0.15% or more, 0.18% or more, 0.2% or more, 0.22% or more, 0.25% or more, 0.28% or more, or even 0.3% or more, and simultaneously 1.5% or less, 1.4% or less, 1.3% or less, 1.2% or less, 1.1% or less, 1% or less, 0.9% or less, 0.8% or less, or even 0.7% or less, in amounts of polymer additives.

[0061] The organosilicon composition of the present invention comprises one or more hydrosilylation catalysts as component (E). The hydrosilylation catalyst can promote the addition reaction between component (B) and component (C). The hydrosilylation catalyst may include a platinum group metal catalyst. Such hydrosilylation catalysts may include (e1) metals selected from platinum, rhodium, ruthenium, palladium, osmium, and iridium, preferably platinum; (e2) compounds of such metals, including, for example, triphenylphosphine-rhodium(I) (Wilkinson's Catalyst), diphosphine-rhodium chelates such as [1,2-bis(diphenylphosphine)ethane]dichlororhodium or [1,2-bis(diethylphosphine)ethane]dichlororhodium, chloroplatinic acid (Speier's Catalyst), chloroplatinic acid hexahydrate, or platinum dichloride; (e3) complexes of platinum group metal compounds with low molecular weight organopolysiloxanes; (e4) platinum group metal compounds or combinations thereof microencapsulated in a matrix or core-shell structure; and (e5) complexes or combinations thereof microencapsulated in a resin matrix. Complexes of platinum with low molecular weight organopolysiloxanes include complexes of 1,3-divinyl-1,1,3,3-tetramethyldisiloxane with platinum (Karstedt catalysts). Exemplary hydrosilylation catalysts are described in U.S. Patents 3,159,601 and 3,220,972.

[0062] The concentration of the hydrosilylation catalyst is sufficient to catalyze the hydrosilylation reaction between silicon-bonded hydrogen atoms and alkenyl groups. Typically, based on the total weight of the organosilicon composition, the concentration of the hydrosilylation catalyst is sufficient to simultaneously provide 1 part per million (ppm) or more, 5 ppm or more, 10 ppm or more, 20 ppm or more, or even 30 ppm or more, while simultaneously providing 6,000 ppm or less, 5,000 ppm or less, 4,000 ppm or less, 3,000 ppm or less, 2,000 ppm or less, 1,000 ppm or less, 500 ppm or less, 100 ppm or less, or even 50 ppm or less of platinum group metals.

[0063] The organosilicon compositions of the present invention may contain one or more hydrosilylation reaction inhibitors (inhibitors) as component (F), which may optionally be used to alter the reaction rate of silicon-bonded hydrogen atoms with alkenyl groups in the organosilicon composition, such as compared with the reaction rate of the same starting material but without the inhibitor. Examples of suitable inhibitors include alkynols, such as methylbutynol, etynylcyclohexanol, dimethylhexynol, and 3,5-dimethyl-1-hexyn-3-ol, 1-butyn-3-ol, 1-propyn-3-ol, 2-methyl-3-butyn-2-ol, 3-methyl-1-butyn-3-ol, 3-methyl-1-pentyn-3-ol, 3-phenyl-1-butyn-3-ol, 4-ethyl-1-octyyn-3-ol, 3,5-dimethyl-1-hexyn-3-ol, and 1-etynyl-1-cyclohexanol and combinations thereof; cycloalkenylsiloxanes, such as methylvinylcyclosiloxanes, examples of which include 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane, 1,3,5,7-tetramethyl-1,3,5,7 -Tetrahexenylcyclotetrasiloxanes and combinations thereof; alkenylene compounds, such as 3-methyl-3-penten-1-yne, 3,5-dimethyl-3-hexen-1-yne and combinations thereof; triazoles, such as benzotriazoles; phosphines; thiols; hydrazides; amines, such as tetramethylethylenediamine, 3-dimethylamino-1-propyne, n-methylpropynylamine, propynylamine and 1-ethynylcyclohexylamine; dialkyl esters of fumarate such as diethyl fumarate, dienyl fumarate such as diallyl fumarate, dialkoxyalkyl fumarate, maleic esters such as diallyl maleate and diethyl maleate; nitriles; ethers; carbon monoxide; alkenes, such as cyclooctadiene, divinyltetramethyldisiloxane; alcohols, such as benzyl alcohol; or combinations thereof.

[0064] For example, by weight, based on the total weight of the organosilicon composition, the hydrosilylation inhibitors that can be used in the present invention may be present in the organosilicon composition in amounts of 0 or more, 0.01% or more, 0.02% or more, 0.03% or more, 0.05% or more, or even 0.1% or more, and simultaneously in amounts of 0.3% or less, 0.25% or less, 0.2% or less, or even 0.15% or less.

[0065] The organosilicon compositions of the present invention may contain one or more polyorganosilicon resins as component (G). The polyorganosilicon resins include those of formula R. M 3SiO 1 / 2 The monofunctionalized unit (“M” unit) and the formula SiO 4 / 2 The tetrafunctionalized silicate unit (“Q” unit), wherein each R M It is independently alkyl or alkenyl. Derived from R MThe alkyl group typically has 1 to 6 carbon atoms or 1 to 3 carbon atoms. Examples of alkyl groups include methyl, ethyl, propyl, pentyl, hexyl, and cyclohexyl. (The last part, "by R," appears to be a typo and should be removed.) M The alkenyl group typically has 2 to 6 carbon atoms. Examples of alkenyl groups include vinyl, allyl, butenyl, and hexenyl. Preferably, the alkyl group is methyl, and the alkenyl group is vinyl.

[0066] The polyorganosilicate resins that can be used in this invention are generally made of R M 3SiO 1 / 2 unit and SiO 4 / 2 Unit composition. "Basically composed of..." means that, by weight, based on the total weight of the polyorganosilicate resin, the combined amount of M units and Q units in the polyorganosilicate resin is 98% or more. The polyorganosilicate resin also contains HOSiO 3 / 2 The unit (TOH unit) explains the content of silicon-bound hydroxyl groups in the polyorganosilicate resin. Based on the total weight of the polyorganosilicate resin, the content of silicon-bound hydroxyl groups in the polyorganosilicate resin, as determined by NMR analysis, is typically less than 2% by weight or less than 1% by weight. Polyorganosilicate resins may contain hydroxyl groups having the formula (R... M The novel pentameric organopolysiloxane (SiO)4Si is a byproduct of the preparation of resins according to the method of Daudt et al. as described in U.S. Patent No. 2,676,182, which is hereby incorporated by reference to teach how to prepare polyorganosilicate resins.

[0067] As determined by NMR analysis, the molar ratio of M units to Q units in polyorganosilicate resins is typically in the range of 0.5 to 1.5, 0.65 to 1.3, or 0.8 to 1.2. The M / Q ratio represents the total number of M units to the total number of Q units in the polyorganosilicate resin, and includes contributions from any new pentamers (if present).

[0068] The polyorganosilicate resins used in this invention may contain an average of 3 mol% or more, 4 mol% or even 5 mol%, and simultaneously 20 mol% or less, 17 mol% or less, or even 15 mol% or less of alkenyl groups. The molar percentage of alkenyl groups in the resin is defined herein as the ratio of the number of moles of alkenyl-containing siloxane units in the resin to the total number of moles of siloxane units in the resin multiplied by 100%. The total number of moles of siloxane units in the resin includes the aforementioned M units, Q units, and TOH units, which can be determined by NMR analysis.

[0069] The preferred polyorganosilicate resin is essentially composed of CH=CH(CH3)2SiO 1 / 2 Unit, (CH3)3SiO 1 / 2unit and SiO 4 / 2 The resin is composed of units, wherein the M unit (including CH=CH(CH3)2SiO) 1 / 2 Unit and (CH3)3SiO 1 / 2 (unit) and Q unit (i.e., SiO) 4 / 2 The molar ratio of the units is 0.8, and the resin contains 5 mol% and 1.8 wt% vinyl groups. The weight percentage of vinyl groups in the resin, as determined by NMR analysis, is defined here as the total molar amount of vinyl groups in the resin multiplied by 100% of the molecular weight of the resin.

[0070] The organosilicon compositions of the present invention may contain one or more adhesion promoters as component (H). Adhesion promoters may include alkoxysilanes (including unsaturated or epoxy-functionalized alkoxysilanes), combinations of alkoxysilanes and hydroxyl-functionalized polyorganosiloxanes (i.e., physical blends and / or reaction products), or mixtures thereof. Examples of suitable epoxy-functionalized alkoxysilanes include 3-epoxypropoxypropyltrimethoxysilane, 3-epoxypropoxypropyltriethoxysilane, (epoxycyclohexyl)ethyldimethoxysilane, (epoxycyclohexyl)ethyldiethoxysilane, or mixtures thereof. Examples of suitable unsaturated alkoxysilanes include vinyltrimethoxysilane, allyltrimethoxysilane, allyltriethoxysilane, hexenyltrimethoxysilane, undecenyltrimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3-methacryloyloxypropyltriethoxysilane, 3-acryloyloxypropyltrimethoxysilane, 3-acryloyloxypropyltriethoxysilane, or mixtures thereof.

[0071] Preferably, the adhesion promoter is a reaction product and / or blend of an epoxy-functionalized alkoxysilane with a hydroxyl-terminated polyorganosiloxane, such as a hydroxyl-terminated vinyl polyorganosiloxane. The adhesion promoter may include a combination of 3-epoxypropoxypropyltrimethoxysilane and a hydroxyl-terminated vinyl polydimethylsiloxane (i.e., a physical blend and / or reaction product), preferably a blend and / or reaction product of 3-epoxypropoxypropyltrimethoxysilane and a hydroxyl-terminated methyl vinyl / dimethylsiloxane copolymer. Suitable commercially available adhesion promoters may include, for example, SYL-OFF. TM 297. SYL-OFF TM 397 and SYL-OFF TM SL 9250, all of them are available from Dow Silicones Corporation of Midland, Michigan, USA (SYL-OFF is a trademark of Dow Silicones Corporation).

[0072] Based on the total weight of the silicone composition, the adhesion promoters used in this invention may be present in the silicone composition in amounts of 0 or more, 0.01% or more, 0.05% or more, 0.1% or more, or even 0.5% or more, and simultaneously in amounts of 5% or less, 4.5% or less, 4% or less, 3.5% or less, 3% or less, 2.5% or less, 2% or less, 1.5% or less, or even 1% or less, by weight.

[0073] In addition to the components described above, the organosilicon composition of the present invention may also contain one or more of the following additives: fillers other than conductive fillers, pigments, and antioxidants. These additives may be present in the organosilicon composition in a total amount of 0 to 0.5%, 0.01% to 0.2%, or 0.05% to 0.15% by weight, based on the total weight of the organosilicon composition.

[0074] The organosilicon compositions of the present invention can be prepared by mixing components (A) to (E) and (F) (if used) and any optional components described above, typically at room temperature. The organosilicon compositions can be single-component or multi-component compositions. The mixing of the components in the organosilicon composition can be achieved by any technique known in the art, such as grinding, blending, and stirring, in a batch or continuous process. The organosilicon compositions can be prepared without the aid of solvents, while still achieving the desired low complex viscosity. Therefore, the organosilicon compositions of the present invention can be solvent-free (i.e., solvent-free or may contain trace amounts of residual solvent from the delivery of components in the organosilicon composition). The term "low complex viscosity" as used herein refers to a complex viscosity of 350,000 Pa·s or less at room temperature when measured within 2 hours of mixing all components of the silicone composition together. For example, a complex viscosity of 1,000 Pa·s or higher, 1,500 Pa·s or higher, 2,000 Pa·s or higher, and simultaneously 350,000 Pa·s or less, 200,000 Pa·s or less, 100,000 Pa·s or less, 20,000 Pa·s or less, 15,000 Pa·s or less, or even 10,000 Pa·s or less, as measured according to the test methods described in the Examples section below. The silicone compositions of the present invention are typically stored in sealed containers to prevent exposure to air and moisture. The silicone compositions of the present invention can be stored at room temperature for several weeks or at temperatures below 0°C, preferably -30°C to -20°C, without any change in the properties of the cured product (e.g., silicone adhesive) made from the silicone composition. The silicone compositions of the present invention are more stable than similar silicone compositions that lack only the polymer additive (E) (i.e., existing silicone compositions). For example, after being stored at room temperature for 3 months or longer, the silicone compositions of the present invention do not exhibit any oily liquid seepage (i.e., a matte surface) on their surfaces as observed by the naked eye.

[0075] The silicone compositions of the present invention can be used in a range of applications, such as curing silicone compositions to form conductive adhesives, conductive coatings, electromagnetic interference (EMI) shielding materials, anti-stick coatings, molding compounds; and as protective coatings for electronic circuit systems, planar surfaces, fibers or small particles or padding materials. The silicone compositions are curable compositions. Upon curing, the silicone compositions form a cured product with high electrical conductivity. "High electrical conductivity" herein is indicated by a volume resistivity of 0.01 ohm·cm or less, preferably 0.001 ohm·cm or less, more preferably 0.0001 ohm·cm or less, as measured according to GB / T 1552-1995 (Chinese National Standard Test Method for Measuring Resistivity of Monocrystalline Silicon and Germanium by Collinear Four-Probe Array). The silicone compositions of the present invention are particularly useful for preparing conductive silicone adhesives.

[0076] This invention also relates to a silicone adhesive comprising a cured product of a silicone composition, i.e., a silicone adhesive formed by curing the silicone composition through a hydrosilylation reaction. The silicone adhesive can be used to form an adhesive article on a substrate by applying the silicone composition to the substrate. The silicone composition can be applied to the substrate by various methods, including, for example, dispensing, spin coating, spraying, spraying, dipping, casting, screen printing, extrusion, or by using a brush, roller, or coating bar. The substrate can be any material capable of withstanding the curing conditions described below for curing the silicone composition to form a silicone adhesive on the substrate. Suitable substrates may include, for example, epoxy resins, polycarbonates, poly(butylene terephthalate) resins, polyamide resins, and blends thereof, such as blends of polyamide resins with isotriastic polystyrene, acrylonitrile-butadiene-styrene, styrene-modified poly(phenylene ether), poly(phenylene sulfide), vinyl esters, polyphthalamide, polyimide, silicon, aluminum, stainless steel alloys, titanium, copper, nickel, silver, gold, or combinations thereof, preferably substrates suitable for electronic applications. For example, the present invention can provide electronic devices comprising a substrate and a silicone composition or silicone adhesive disposed on the substrate. Curing of the silicone composition may be carried out at room temperature or at a high temperature of up to 200°C, for example, 70°C to 200°C, 125°C to 175°C, for a time sufficient to cure the silicone composition (e.g., 1 to 3 hours). Compared to existing silicone compositions, curing the silicone compositions of the present invention produces silicone adhesives with improved electrical conductivity, as indicated by low volume resistivity. For example, silicone adhesives made from the silicone compositions of the present invention can exhibit a reduction in volume resistivity (VR) of at least 50% compared to silicone adhesives made from conventional silicone compositions; for example, a reduction in VR of at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, or even at least 99%. As described above, the silicone adhesives of the present invention can exhibit high electrical conductivity. The silicone adhesives of the present invention can also exhibit better retention of these electrical properties after thermal cycling at 125°C for at least 20 days, 30 days, or even 60 days or more. For example, the VR change of the silicone adhesives of the present invention can show a reduction in VR change of at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, or even at least 99% compared to silicone adhesives made from conventional silicone compositions.

[0077] The present invention also provides a method for bonding a first substrate to a second substrate. The method includes (i) applying a silicone composition to the surface of at least one of the substrates, (ii) bringing both substrates into contact with the silicone composition therebetween, and (iii) curing the silicone composition. The two substrates are those described above and may be the same or different. The curing of the silicone composition may be performed as described above.

[0078] Example

[0079] Some embodiments of the invention will now be described in the following examples, wherein all parts and percentages are by weight unless otherwise stated. The following materials are used in the examples:

[0080] Conductive fillers available from Potters Industries include:

[0081] CONDUCT-O-FIL TM SN08P40 silver-coated nickel microparticles (particle size: 8μm, 40wt% silver content);

[0082] CONDUCT-O-FIL SN40P18 silver-coated nickel microparticles (18wt% silver content) with a particle size of 40μm;

[0083] CONDUCT-O-FIL S3000S3N silver-coated glass spherical particles (particle size: 34μm, 12wt% silver content); and

[0084] CONDUCT-O-FIL SA300S20 Silver-coated aluminum microparticles (particle size: 40μm, 20wt% silver content) (CONDUCT-O-FIL is a trademark of Porter Industries).

[0085] 1-Ethynyl-1-cyclohexanol (ETCH), which is available from TCI, can be used as an inhibitor.

[0086] The inhibitor A that can be obtained from TCI is 3,5-dimethyl-1-hexyn-3-ol.

[0087] The Pt (platinum) catalyst available from Gelest is SIP6831.2 platinum-divinyltetramethyldisiloxane complex, with 2% Pt in xylene (based on the weight of the Pt catalyst).

[0088] The following materials are all available from Dow Silicones:

[0089] Hydrogenated polydimethylsiloxane (PDMS) possesses the properties of (CH3)3SiO-[(CH3)2SiO].3.34 -[HCH3SiO] 5.32 The structure of -Si(CH3)3.

[0090] Vinyl-terminated PDMS has the following structure: CH2=CH-(CH3)2SiO-[(CH3)2SiO] m The structure is -Si(CH3)2-CH=CH2, where m is 162, 324, 41, and 554 for vinyl-terminated PDMS-A, vinyl-terminated PDMS-B, vinyl-terminated PDMS-C, and vinyl-terminated PDMS-D, respectively.

[0091] Vinyl-terminated MQ resins have an average chemical structure: M Vi 0.05 M 0.4 Q 0.55 The Vi content is 5 mol% and 1.8 wt% (the molar and weight content of Vi groups are as defined in the polyorganosilicate resin section above), where M Vi This represents CH2=CH(CH3)2SiO 1 / 2 And Vi represents CH2=CH-.

[0092] DOWSIL TM 193C fluid (“DC-193C SPE”) is a silicone-modified polyether (M n 3,096 g / mol (as determined by the following GPC assay; DOWSIL is a trademark of Dow Silicones).

[0093] The adhesion promoter is a combination of glycidyloxypropyltrimethoxysilane and hydroxyl-terminated methyl vinyl / dimethylsiloxane copolymer.

[0094] All the polyols listed in the table below are available from The Dow Chemical Company:

[0095]

[0096]

[0097] 1 OHV indicates the hydroxyl value of an alcohol alkoxylate as determined by ASTM D4274-2011; N / A - Not available; 2 Mn was calculated using 56100 (mg / mol) * f / OHV (mgKOH / g); 3 The wt% of PO refers to the weight content of propylene oxide units relative to the total weight of alcohol alkoxylates.

[0098] CARBOWAX, TERGITOL, and DOWFAX are trademarks of Dow Chemical Company.

[0099] The following standard analytical equipment and methods were used in the embodiments and to determine the properties and characteristics described herein:

[0100] NMR

[0101] The description in reference embodiment 2 of U.S. Patent 9,593,209, in column 32 29 Si and 13 Nuclear magnetic resonance (NMR) technology is used to measure the molar percentage of methyl groups, the weight content of silicon-bonded hydrogen atoms, the content of silicon-bonded hydroxyl groups, and M(R) values. M 3SiO 1 / 2 ) and Q(SiO 4 / 2 The molar ratio of the alkenyl (e.g., vinyl) units, and the molar percentage and weight percentage of the alkenyl (e.g., vinyl) groups mentioned above.

[0102] GPC

[0103] The number-average molecular weight (Mn) of the organosilicon-modified polyether was determined using GPC analysis. n The chromatographic apparatus consisted of a Waters 2695 separation module equipped with a vacuum degasser and a Waters 2414 refractive index detector. Three Styragel... TM HR column (300 mm × 7.8 mm) (molecular weight separation range 100 to 4,000,000), followed by Styragel. TM Separation was performed using a guard column (30 mm × 4.6 mm), Styragel, a trademark of Waters Technologies Corporation. Analysis was performed using certified-grade tetrahydrofuran (THF) flowing at 1.0 mL / min as the eluent, with both the column and detector heated to 35°C. A 1.0% wt. / v sample was prepared by weighing 0.050 g into an 8 mL glass vial and diluting with 5 mL of THF. After filtration through a 0.45 μm polytetrafluoroethylene (PTFE) filter, the sample solution was transferred to a glass autosampler vial. A 100 μL injection volume was used, and data were collected over 37 minutes. Data collection and analysis were performed using Waters Empower GPC software. The molecular weight average was determined relative to a calibration curve (3rd order) created using polystyrene standards covering a molecular weight range of 474–1,270,000.

[0104] Volume resistivity (VR) )

[0105] The silicone composition was cast into a mold (20mm*6mm*0.4mm (thickness)) on a glass slide and cured at 150°C for 2 hours to form a cured sample. The cured sample was placed at room temperature for 12 hours prior to VR testing. The volume resistivity of the cured sample was measured using a 4-probe volume resistivity meter (ST2253) from Suzhou Jingge Electronic Co., Ltd. (China) according to GB / T 1552-1995.

[0106] The cured sample prepared on the glass slide is placed under a 4-probe VR tester, and the initial VR of the sample is measured, denoted as VR. 初始 The samples were then placed in an oven and subjected to thermal aging at 125°C for a specific period (20 to 60 days), followed by cooling to room temperature for more than 12 hours. The VR of the samples after thermal aging was measured and denoted as VR. 老化处理 The change in VR before and after thermal aging treatment is calculated based on the following equation, and expressed as VR. 变化 :

[0107] VR 变化 =(VR) 老化处理 -VR 初始 ) / VR 初始 *100%

[0108] Median particle size of conductive fillers

[0109] By measuring 10 8 The volume-weighted particle size distribution of each particle was determined using a laser diffractometer (model LS 13 320) from Beckman Coulter, which measures the particle size of the filler, i.e., the D50 median particle size.

[0110] Complex viscosity

[0111] All components of the silicone composition were mixed together. The complex viscosity of the resulting silicone composition was measured over two hours using an TA DHR-III rheometer (TA Instruments) at room temperature, at 1% strain and an angular frequency of 0.1 radians / second (rad / s), across 25 parallel cross-hatched plates, employing oscillation frequency scanning and Cox-Merz transformation. Based on the measured complex viscosity, the silicone compositions were classified as follows:

[0112] "Powder" indicates a viscosity >550,000 Pa·s, "gel" indicates a viscosity in the range of >350,000 Pa·s to 550,000 Pa·s, "paste" indicates a viscosity in the range of >10,000 Pa·s to 350,000 Pa·s, and "viscous" indicates a viscosity in the range of 1,000 Pa·s to 10,000 Pa·s.

[0113] Shelf life

[0114] The shelf life of the silicone composition was determined by first mixing all components and then storing the resulting silicone composition at room temperature for 3 months. The appearance of the silicone composition before and after storage was observed and recorded separately. If no oily liquid was observed on the surface of the silicone composition after storage (i.e., no bleeding or dull surface), the silicone composition was stable. Otherwise, if the surface of the silicone composition was glossy after storage, the silicone composition was unstable.

[0115] Organosilicon compositions of Examples (IE) 1 to IE22 and Comparative Examples (CE) 1 to CE20 of the present invention

[0116] Preparation of premix S-1: Add all the components of premix S-1 listed in Table 1-1 to a polypropylene (PP) bottle and mix twice at 3,000 rpm for 30 seconds using a dental mixer to obtain premix S-1.

[0117] Based on the components listed in Tables 1 and 2, premix S-2 (S-2) was prepared according to the same procedure as the preparation of premix S-1 described above.

[0118] A certain amount of the premix S-1 or premix S-2 prepared thus was then placed in a separate bottle and mixed with the other components of the silicone compositions given in Tables 2 to 7 for 1 minute at 2,000 rpm under vacuum using a dental mixer to obtain the silicone composition. The viscosity and VR properties of the obtained silicone composition were evaluated according to the test methods described above, and the results are given in Tables 2 to 7.

[0119] Table 1-1 Premix S-1

[0120] hydride PDMS 6 Vinyl-terminated MQ resin 13.95 Vinyl-terminated PDMS-B 32.40 Vinyl-terminated PDMS-A 46.2 Pt catalyst 0.4 Inhibitor A 0.2 Adhesion promoter 0.85 total 100

[0121] *wt% refers to the weight percentage relative to the total weight of premix S-1.

[0122] Table 1-2 Premix S-2

[0123]

[0124]

[0125] *wt% refers to the weight percentage relative to the total weight of premix S-2.

[0126] As shown in Table 2, all silicone compositions from IE1 to IE4 exhibited the desired viscosity. In contrast, the silicone composition of CE1 exhibited an undesirable high complex viscosity and appeared gel-like. The silicone compositions from IE1 to IE4 provided significantly better electrical conductivity for the cured products prepared from them than those from CE1 to CE5, as indicated by the lower VR. Specifically, compared to CE1, the silicone compositions from IE1 to IE4 showed a 100-fold reduction in VR upon curing, and showed a reduction in VR including M with a concentration of 1,000 g / mol. n The cured product of PPG (CE4) contains more than 50% of VR.

[0127] Table 2. Organosilicon compositions and VR properties

[0128] Premix S-1 12 12 12 12 12 12 12 12 12 SN08P40 88 88 88 88 88 88 88 88 88 PEG 200 0.3 P400PPG 0.3 P1000PPG 0.3 L-61EO / PO 0.3 P4000PPG 0.3 DF-103EO / PO 0.3 DF-162EO / PO 0.3 DF-163EO / PO 0.3 Complex viscosity / appearance gel paste paste paste paste paste sticky sticky sticky <![CDATA[VR 初始 (mΩ·cm)]]> 64.5 16.7 1.81 1.36 0.779 0.464 0.588 0.368 0.403

[0129] mΩ·cm represents milliohm-centimeter.

[0130] As shown in Table 3, compared with the CE1 composition lacking any polymer additives or the CE3 and CE6 to CE7 compositions containing P400 PPG, PEG600 and SPE respectively, the silicone compositions of IE2 to IE4 provide much smaller VR changes upon curing.

[0131] Table 3. Changes in the silicone composition and VR after thermal aging treatment

[0132]

[0133]

[0134] NC - No conductivity

[0135] As shown in Table 4, all silicone compositions from IE5 to IE10 exhibited the desired viscosity. In contrast, the silicone composition of CE8 exhibited an undesirable high complex viscosity and appeared gel-like. The silicone compositions of IE5 and IE8 provided significantly better electrical conductivity for the cured products prepared from them than CE8, as indicated by a VR reduction of more than 70% compared to the cured product prepared from CE8. The silicone compositions of IE6 and IE9 provided significantly better electrical conductivity than CE9, as indicated by a VR reduction of more than 80% compared to the cured product prepared from CE9. The silicone compositions of IE7 and IE10 provided significantly better electrical conductivity than CE10, as indicated by a VR reduction of more than 99% compared to the cured product prepared from CE10. The silicone compositions of IE5 to IE10 also provided significantly better electrical conductivity upon curing than CE11 and CE12.

[0136] Table 4. Organosilicon compositions and VR properties

[0137]

[0138]

[0139] As shown in Table 5, the silicone compositions of IE9 provided a much smaller VR change upon curing compared to CE9 (lacking any polymer additives) or CE14 (containing SPE). The silicone compositions of IE11 and IE12 also provided a much smaller VR change upon curing compared to CE13 (lacking any polymer additives).

[0140] Table 5. Organosilicon compositions and VR properties

[0141] Premix S-1 12 12 12 Premix S-2 15.5 15.5 15.5 SN40P18 88 84.5 84.5 84.5 88 88 DC-193C SPE 0.4 DF-162EO / PO 0.3 DF-163EO / PO 0.4 0.3 <![CDATA[VR 初始 (mΩ·cm)]]> 22.7 10.3 1.65 1.11 0.678 0.598 <![CDATA[VR 老化处理 (mΩ·cm), 125℃ / 30 days 148 128 62.3 6.4 1.96 2.01 <![CDATA[VR 变化 125℃ / 30 days 552％ 1148％ 3683％ 475％ 189％ 236％

[0142] As shown in Table 6, all silicone compositions from IE13 to IE18 exhibited the desired viscosity. Furthermore, after 3 months of storage at room temperature, the silicone composition of CE16 showed significant bleeding (i.e., a glossy surface), while no bleeding was observed in the silicone compositions (IE14 and IE17) with the same filler loading.

[0143] The silicone compositions IE13 and IE16 provide cured products with a VR (Viscosity Ratio) that is more than 75% lower than that of the cured product prepared from CE15. The silicone compositions IE14 and IE17 provide cured products with a VR that is more than 50% lower than that of the cured product prepared from CE16. The silicone compositions IE15 and IE18 provide cured products with a VR that is more than 99% lower than that of the cured product prepared from CE17. This indicates that the silicone compositions IE13 and IE16, IE14 and IE17, and IE15 and IE18 provide cured products with significantly better initial conductivity than CE15, CE16, and CE17, respectively. Furthermore, the silicone compositions IE13 and IE16 provide a much smaller VR change during curing than CE15, while IE16 provides an even smaller VR change than IE13.

[0144] Table 6. Organosilicon compositions and VR properties

[0145]

[0146] N / A - Not available

[0147] As shown in Table 7, all silicone compositions from IE19 to IE22 exhibited the desired viscosity. Furthermore, after 3 months of storage at room temperature, the silicone composition of CE19 showed significant bleeding (i.e., a glossy surface), while no bleeding was observed in the silicone composition with DF-163 at the same filler loading (IE20).

[0148] Compared to CE18, the silicone compositions of IE19 and IE22 offer a VR reduction of over 60%. The cured product prepared from IE20 shows a 65% reduction in VR compared to the cured product prepared from CE19, and the cured product prepared from IE21 offers a 99% reduction in VR compared to the cured product prepared from CE20. This indicates that the silicone compositions of IE19 and IE22, and IE20 and IE21, provide significantly better initial conductivity for the cured products prepared from them compared to the initial conductivity of CE18, CE19, and CE20, respectively. Furthermore, the silicone compositions of IE19 and IE22 offer a much smaller VR change during curing than CE18, indicating superior conductivity retention compared to CE18.

[0149] Table 7. Properties of organosilicon compositions and cured products prepared therefrom

[0150]

[0151] N / A - Not available

Claims

1. An organosilicon composition, based on the total weight of the organosilicon composition, comprising: (A) 66% to 89% conductive filler; (B) 5% to 40% of polydiorganosiloxane polymers of formula (I), (R 1 3SiO 1 / 2 )2(R 1 2SiO 2 / 2 ) n (I), Each R 1 Independently, it is a monovalent aliphatic hydrocarbon group, n is in the range of 35 to 1,000, and the polydiorganosiloxane polymer contains an average of at least two alkenyl groups per molecule; (C) Polyorganohydrosiloxanes of Formula (II), (R 2 3SiO 1 / 2 )2(R 2 2SiO 2 / 2 ) m (II) Each R 2 Independently, it is hydrogen or an alkyl group having 1 to 20 carbon atoms, m is in the range of 5 to 200, and the polyorganohydrosiloxane has an average of at least three silicon-bonded hydrogen atoms per molecule; (D) Catalyst for hydrosilylation reaction; (E) 0.1% to 1.5% of a polymer additive having a molecular weight greater than 2,000 g / mol to 20,000 g / mol, wherein the polymer additive is selected from alcohol-initiated ethylene oxide and propylene oxide copolymers, wherein the alcohol-initiated ethylene oxide and propylene oxide copolymers have the structure of formula (III): (A) z B(III) Where A represents HO-(CHR) p -CHR q -O) x -(CH2-CH2-O) y - where x ranges from 8 to 40, y ranges from 1 to 20, and R p and R q Different and selected from hydrogen and -CH3, z is 1 to 12; and B is hydrogen or a monovalent hydrocarbon group, divalent hydrocarbon group or polyvalent hydrocarbon group having 3 to 18 carbon atoms; and (F) 0% to 0.3% inhibitors of hydrosilylation reaction.

2. The organosilicon composition according to claim 1, wherein, by weight, based on the weight of the alcohol-initiated ethylene oxide and propylene oxide copolymer, the copolymer comprises 50% to 99% propylene oxide units.

3. The organosilicon composition according to claim 1 or 2, wherein the alcohol-initiated ethylene oxide and propylene oxide copolymer has a molecular weight of 3,000 g / mol to 14,000 g / mol.

4. The organosilicon composition according to claim 1 or 2, wherein the conductive filler comprises particles composed of silver or its alloys, silver-coated nickel particles, silver-coated glass particles, silver-coated aluminum particles, silver-coated copper particles, or mixtures thereof.

5. The organosilicon composition according to claim 1 or 2, wherein in formula (I), n is 35 to 500, and at least 50 mol% is derived from R 1 The monovalent aliphatic hydrocarbon group indicated is methyl.

6. The organosilicon composition according to claim 1 or 2, wherein, based on the weight of the polyorganohydrosiloxane, the polyorganohydrosiloxane contains 0.38% to 2% of the silicon-bonded hydrogen atoms.

7. The organosilicon composition according to claim 1 or 2, wherein the hydrosilylation reaction catalyst comprises platinum.

8. The organosilicon composition according to claim 1 or 2, wherein the molar ratio of silicon-bonded hydrogen atoms in the polyorganohydrosiloxane to alkenyl groups in all components of the organosilicon composition is 0.5 to 10.

9. The organosilicon composition according to claim 1 or 2, wherein the organosilicon composition further comprises a polyorganosilicon resin, the polyorganosilicon resin being substantially composed of R M 3SiO 1 / 2 unit and SiO 4 / 2 Unit composition, where each R M Independently, it is alkyl or alkenyl, wherein the polyorganosilicon resin contains an average of 3 mol% to 20 mol% alkenyl groups.

10. The organosilicon composition according to claim 1 or 2, wherein the organosilicon composition further comprises an adhesion promoter.

11. The organosilicon composition according to claim 10, wherein the adhesion promoter is selected from glycidoxypropyltrimethoxysilane, hydroxyl-terminated vinyl-functionalized polydimethylsiloxane, or combinations thereof.

12. A method for preparing the organosilicon composition according to claim 1, the method comprising mixing the conductive filler, the polydiorganosiloxane polymer, the polyorganohydrosiloxane, the hydrosilylation catalyst, the polymer additive, and, if used, the hydrosilylation inhibitor.

13. A silicone adhesive comprising a cured product of a silicone composition according to any one of claims 1 to 11.

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