Silicone composition and its uses

Abstract

Fast-curing, two-part, condensation-curable silicone compositions are provided that cure using titanium and / or zirconium-based catalysts to produce cured gel materials and are suitable for encapsulating and / or embedding electrical and / or electronic articles.

Description

Technical Field

[0001] The present disclosure relates to a fast-curing two-component condensation-curable silicone composition that cures using a titanium and / or zirconium-based catalyst to produce a cured gel material, and uses thereof.

[0002] In many cases, silicone-based materials such as gels used as coating materials, embedding materials, and encapsulating materials need to maintain adhesion to a substrate and / or other materials. For example, in electronics, gels are a special class of encapsulants that cure to form very soft materials. Their main roles are ● to function as a dielectric insulator, ● to protect circuits from moisture and other contaminating substances, ● to relieve mechanical and thermal stresses on components, and thereby protect electronic assemblies and components from a hostile environment.

[0003] In such situations, it is necessary to adhere the gel to electronic and electrical components and printed circuit boards in addition to electrical connectors and conductors passing through the coating or encapsulating material.

[0004] Commercially available cured gel materials used to form encapsulants and embedding materials (e.g., gels) are based on addition-curing chemistry, i.e., they are cured by a reaction in which a hydrosilyl group and an unsaturated carbon group are catalyzed by a typically platinum-based compound, and are expensive. For many years, in the industry, this type of addition-curing composition has been preferred for the above applications because it cures immediately through the composition body and becomes a cured material within a few minutes, but the condensation-curing system is significantly slower, and in the titanate-curing condensation process, for example, it can take up to 7 days to cure per 6 mm depth of the uncured material body. The tin-curing condensation system cures in a shorter period, but undergoes a reverse reaction (i.e., depolymerization) at temperatures higher than 80°C, and thus is not desirable for, for example, electronics applications.

[0005] Materials produced from hydrosilylation-curing compositions are excellent from the viewpoint of curing speed, but there are some potential problems and / or disadvantages associated with their use. For example, they are generally cured at high temperatures (i.e., higher than 100 °C), there is a risk of contamination, and expensive platinum-based curing catalysts are susceptible to the influence of amine-containing compounds, sulfur-containing compounds, and phosphorus-containing compounds and are at risk of being poisoned, which may result in non-curability due to catalyst deactivation.

[0006] It is known to those skilled in the art that alkoxytitanium compounds (i.e., alkyl titanates) are suitable catalysts for formulating one-component moisture-curing silicones (References: Noll, W.; Chemistry and Technology of Silicones, Academic Press Inc., New York, 1968, p. 399, Michael A. Brook, silicon in organic, organometallic and polymer chemistry, John Wiley & sons, Inc. (2000), p. 285). Titanate catalysts have been widely described for use in formulating skin- or diffusion-cured one-part condensation-curing gel materials, such as elastomers and / or gels. These formulations are typically available in one-part packages applied to layers thinner than 15 mm. Layers thicker than 15 mm are known to result in uncured material in the deep part of the material, because the diffusion of moisture is very slow in very deep parts. Skin or diffusion curing (e.g., moisture / condensation) occurs when the initial curing process takes place by the formation of a cured skin at the composition / air interface after the sealant / encapsulant has been applied to the substrate surface. After the formation of the surface skin, the curing speed varies depending on the diffusion rate of moisture from the interface between the sealant / encapsulant and air to the interior (or core) of the material, as well as the diffusion of condensation reaction by-products / emissions from the interior (or core) of the material to the exterior (or surface) and the progressive thickening of the cured skin from the exterior / surface to the interior / core over time.

[0007] Until recently, in multicomponent compositions designed to activate condensation curing in the bulk of the product (International Publication No. 2018 / 024858), titanium-based catalysts were not used. These generally use other metal catalysts such as tin catalysts or zinc catalysts, for example dibutyltin dilaurate, tin octoate, and / or zinc octoate (Noll, W.; Chemistry and Technology of Silicones, Academic Press Inc., New York, 1968, p. 397). In silicone compositions stored in two or more parts before use, one part contains a filler, which typically contains the moisture necessary to activate condensation curing in the bulk of the product. Unlike the diffusion-curing one-part systems described above, two-part condensation-curing systems allow bulk curing even in parts deeper than 15 mm when mixed together. In this case, the composition cures throughout the bulk of the material (after mixing). If a skin forms, it is only in the first few minutes after application. Soon after, the product becomes solid throughout.

[0008] Two-part condensation-curing silicone compositions that can be surprisingly cured by the use of an alkyl titanate are disclosed, but the cure rate of such compositions may still prevent their use in applications that require fast curing and / or a reversal time, i.e., the point at which the material no longer flows.

[0009] Typically, soft gels are obtained by formulating at approximately low crosslink density, i.e., by reducing the crosslinker content. As a result, the hardness and modulus of elasticity of the product decrease. Such products are useful as embedding materials for electronics to reduce the impact of thermal cycles on sensitive components. Hard or high-modulus materials induce high stresses in the components during such cycles. However, reducing the crosslinker content in the composition proportionally reduces the reaction rate of curing. As a result, when the two parts are mixed, it may take a long time before a non-sagging gel is formed.

[0010] The object of the present disclosure is to provide a condensation-curable gel that cures rapidly and has no reverse reaction (i.e., a gel having a non-stick time of 1 hour or less (≦) and a reverse time of ≦3 hours at 25°C).

[0011] A multi-part condensation-curable gel composition comprising (i) at least one condensation-curable silyl-terminated polymer having at least two hydroxyl functional groups (silanol groups) per molecule and a viscosity of 1000 mPa·s or less (≦) at 25°C, (ii) a crosslinking agent selected from silyl-functional molecules having at least two silyl groups, each silyl group containing at least two hydrolyzable groups having a viscosity of ≦1000 mPa·s at 25°C, but the viscosity being at least 75% of the viscosity of (i), (iii) a condensation catalyst selected from the group of titanates and zirconates, (iv) one or more reinforcing fillers and / or non-reinforcing fillers, and comprising (a) the catalyst (iii) and the filler (iv) are not stored together before curing, (b) the ratio of Si-OH groups:Si-hydrolyzable groups in the composition is 0.4:1 to 0.95:1, and upon curing, (c) there is provided a multi-part condensation-curable gel composition having a non-stick time of ≦1 hour and a reverse time of ≦3 hours.

[0012] To avoid misunderstanding, the non-stick time is the time in minutes required for the curable material to form a non-sticky surface film, and the reverse time indicates the point in the curing process when the curable composition can no longer flow.

[0013] A cured gel material which is a reaction product of a multi-part condensation-curable gel composition, (i) at least one condensation-curable silyl-terminated polymer having at least two hydroxyl functional groups (silanol groups) per molecule and a viscosity of ≦1000 mPa·s at 25°C, (ii) A crosslinking agent selected from silyl-functional molecules having at least two silyl groups, each silyl group containing at least two hydrolyzable groups and having a viscosity of ≤1000 mPa·s at 25°C, wherein the viscosity is at least 75% of the viscosity of (i), the crosslinking agent, (iii) A condensation catalyst selected from the group of titanates and zirconates, (iv) One or more reinforcing fillers and / or non-reinforcing fillers, comprising, (a) The catalyst (iii) and the filler (iv) are not stored together before curing, (b) The molar ratio of Si-OH groups:Si-alkoxy groups in the composition is from 0.4:1 to 0.95:1, (c) A cured gel material is also provided which, upon curing, has a non-stick time of ≤1 hour and a reverse time of ≤3 hours.

[0014] There is also provided a method for preparing the above-described cured gel material, the method comprising mixing together a plurality of parts of a condensation-curable gel composition and applying and curing the resulting mixture onto a substrate.

[0015] There is also provided the use of the above-described multi-part condensation-curable gel composition in the manufacture of electronic assemblies and electronic components.

[0016] Accordingly, the present disclosure provides a multi-part condensation-curable gel composition using a lower viscosity polymer (≤1000 mPa·s at 25°C) that is more readily available for curing by a crosslinking agent and having a crosslinking agent of similar viscosity (≤1000 mPa·s at 25°C). Such low viscosity materials are expected to provide a harder material, but since the ratio of Si-OH (silanol) groups:Si-alkoxy groups in the composition is from 0.4:1 to 0.95:1, upon curing, the composition provides a soft gel.

[0017] In one alternative, the plurality of component compositions are two-component compositions that, upon curing, provide a material exhibiting a short curing time, e.g., a non-stick time (TFT) and a reverse time upon room temperature curing. As a result, the hardness and modulus of elasticity of the product decrease. This composition cures at room temperature, i.e., it is curable.

[0018] The plurality of component condensation curable gel compositions are typically stored in two parts prior to use. When the composition is a two-component composition, preferably, there is part A containing polymer (i) and reinforcing filler and / or non-reinforcing filler (iv), and part B containing crosslinking agent (ii) and catalyst (iii). The reinforcing filler and / or non-reinforcing filler (iv) and, when present, the catalyst (iii) are stored in different parts.

[0019] The total silicon-bonded hydroxyl (silanol / Si-OH) molar content is calculated for 100 g of the mixed formulation. The molar content of silicon-bonded hydroxyl with respect to the polymer is equal to the amount (in g) of hydroxyl-containing polymer in 100 g of the mixed product divided by the average number of hydroxyl functional groups present in the polymer, typically multiplied by the number average molecular weight (Mn) of the polymer. When several hydroxyl-functional polymers are present in the formulation, the total silanol molar content in the formulation is constituted by adding the molar content of each polymer.

[0020] The total hydrolyzable group molar content is calculated for 100 g of the mixed formulation. The molar content of hydrolyzable groups with respect to a substance is equal to the amount (in g) of molecules containing hydrolyzable groups in 100 g of the mixed product divided by the molecular weight or, in the case of a polymer molecule, the number average molecular weight (Mn), and multiplied by the average number of hydrolyzable functional groups present in the molecule. The total molar content of hydrolyzable groups in the formulation is constituted by adding the molar content of each molecule or polymer. Typically, each hydrolyzable group is an alkoxy group.

[0021] Next, the molar ratio of the silicon-bonded hydroxyl (silanol) groups in polymer (i) to the hydrolyzable groups derived from the crosslinking agent (ii) is calculated by dividing the total molar content of the silicon-bonded hydroxyl groups (Si-OH) in polymer (i) by the total molar content of the hydrolyzable groups derived from the crosslinking agent (ii), and can thus be described as a ratio.

[0022] The number average molecular weight (Mn) and weight average molecular weight (Mw) of the silicone can also be determined by gel permeation chromatography (GPC). This technique is a standard technique, and values of Mw (weight average), Mn (number average) and polydispersity index (PI) [where PI = Mw / Mn] are obtained.

[0023] The Mn values provided in this application are determined by GPC and represent typical values of the polymers used. If not provided by GPC, Mn can also be obtained from calculations based on the dynamic viscosity of the above polymers.

[0024] The main advantages of these compositions are that they cure at room temperature and, together with the titanate condensation catalyst / zirconate condensation catalyst used, form a gel that is more resistant to contaminants than platinum-cured silicones, and also, unlike tin catalyst compositions, provide resistance to reverse reactions when exposed to high temperature and high humidity. The curing of these compositions is much faster than the condensation reactions catalyzed by the typical titanates or zirconates that would be expected, i.e., less than 1 hour has been confirmed to be possible as opposed to the several days for standard one-part titanate-curing materials.

[0025] Polymer (i) is at least one condensation-curable silyl-terminated polymer having at least two hydroxyl functional groups per molecule and a viscosity of ≦1000 mPa·s at 25°C.

[0026] Any suitable moisture / condensation curable silyl-terminated polymer can be used, including polydialkylsiloxane, alkylphenylsiloxane, or an organic polymer having silyl end groups, such as silyl polyether, silyl acrylate, and silyl-terminated polyisobutylene, or any copolymer thereof. Preferably, the polymer is a polysiloxane-based polymer containing at least two Si-hydroxyl (silanol) containing groups, and most preferably, the polymer contains terminal Si-hydroxyl (silanol) containing groups. Examples of suitable Si-hydroxyl (silanol) containing end groups include -Si(OH) 3 , -(R a )Si(OH) 2 , -(R a ) 2 Si(OH), or -(R a ) 2 Si-R c -SiR d p (OH) 3-p [wherein each R a is independently a monovalent hydrocarbyl group, such as an alkyl group having particularly 1 to 8 carbon atoms (methyl is preferred), each R d group is independently an alkyl group or an alkoxy group, this alkyl group preferably has up to 6 carbon atoms, R c is a divalent hydrocarbon group that can be intervened by one or more siloxane spacers having up to 6 silicon atoms, and p is a value of 0, 1 or 2]. For example, each R a can be methyl, R c can be an ethylene or propylene group, or an ethylene group, and p is 0, that is, -(Me) 2 Si-CH 2 -CH 2 -Si(OH) 3 .

[0027] Preferably, the polymer (i) has the general formula X 3 -A-X 1 (1) [wherein X 3 and X 1is independently selected from Si-hydroxyl (silanol) - containing end groups, and A has a siloxane polymer chain and / or an organic-containing polymer chain, or is a siloxane polymer chain.

[0028] Hydroxyl (silanol) - containing end group - end group X 3 Or X 1 Examples of -Si(OH) defined above 3 , -(R a )Si(OH) 2 , -(R a ) 2 Si(OH), or -(R a ) 2 Si-R c -Si(R d ) p (OH) 3-p are included. Preferably, X 3 and / or X 1 is a hydroxydialkyl end, for example, a hydroxydimethyl end, or

[0029] Examples of suitable siloxane groups in the polymer chain A of formula (I) are the siloxane groups that constitute a polydiorganosiloxane chain. Thus, the polymer chain A preferably has the formula (2) -(R 5 s SiO (4-s) / 2 )- (2) [wherein each R 5 is independently an organic group such as a hydrocarbyl group having 1 to 10 carbon atoms, optionally substituted with one or more halogen groups such as chlorine or fluorine, s is 0, 1, or 2, and typically, s has an average value of about 2] and contains siloxane units. Specific examples of the group R 5 include a methyl group, an ethyl group, a propyl group, a butyl group, a vinyl group, a cyclohexyl group, a phenyl group, a tolyl group, a propyl group substituted with chlorine or fluorine, for example, a 3,3,3-trifluoropropyl group, a chlorophenyl group, a β-(perfluorobutyl)ethyl group or a chlorocyclohexyl group. Preferably, the group R 5At least some, preferably substantially all, of them are methyl.

[0030] The polymer (i) herein has a viscosity of ≦1000 mPa·s at 25° C., or 250-1000 mPa·s at 25° C., or 250-750 mPa·s at 25° C., measured using a Brookfield cone-plate viscometer (RV DIII) with the most suitable cone-plate for said viscosity.

[0031] Accordingly, preferred polysiloxanes containing the units of formula (2) are polydiorganosiloxanes having terminal, silicon-bonded hydroxyl groups, otherwise known as silanol-containing end groups (Si—OH). The polydiorganosiloxane may be a homopolymer or a copolymer. Mixtures of different polydiorganosiloxanes having silanol-containing end groups are also suitable.

[0032] Furthermore, the composition has one Si-hydroxyl (silanol)-containing end group, e.g., one —Si(OH) 3 , —(R a )Si(OH) 2 , —(R a ) 2 Si(OH), or —(R a ) 2 Si—R c —SiR d p (OH) 3-p , e.g., a dialkylhydroxy end group, and one non-reactive end group, e.g., a trialkyl end, i.e., a trimethyl end group. Thus, the polymer (i) may further include a polydiorganosiloxane having a partially dialkylhydroxy end and a partially trialkyl end. By including such additional polymers, the modulus of the resulting product after curing can be reduced and / or the adhesion to a difficult-to-adhere substrate can be improved. Such additional polymer (i) may have a viscosity similar to that of the foregoing.

[0033] Alternatively, the polymer (i) may be an organic polymer having silyl end groups each having at least one -OH group. Typical silyl end polymer groups include silyl end polyethers, silyl end acrylates, and silyl end polyisobutylenes. The silyl groups to be used may be one or more of the alternatives described above for X 1 and X 3 and may be one or more of the alternatives described above.

[0034] According to the present invention, the polymer chain A may alternatively be an organic polymer having silyl end groups, such as silyl polyethers, silyl acrylates, and silyl end polyisobutylenes. In the case of silyl polyethers, the polymer chain is based on polyoxyalkylene units. Such polyoxyalkylene units preferably have the general formula (-C n H 2n -O-) y [wherein n is an integer from 2 to 4 and y is an integer of at least 4] and are composed of repeating oxyalkylene units (-C n H 2n -O-) to form a linear, mainly oxyalkylene polymer. Similarly, the viscosity has a viscosity of ≦1000 mPa·s at 25°C, or 250 to 1000 mPa·s at 25°C, or 250 to 750 mPa·s at 25°C and has a suitable number average molecular weight for each polyoxyalkylene polymer block present. Further, the oxyalkylene units do not necessarily have to be the same throughout the entire polyoxyalkylene monomer and may be different for each unit. The polyoxyalkylene block or polymer may be composed of, for example, oxyethylene units (-C 2 H 4 -O-), oxypropylene units (-C 3 H 6 -O-), or oxybutylene units (-C 4 H 8 -O-), or a mixture of these units.

[0035] Other polyoxyalkylene units include, for example, the structure -[-R e-O-(-R f -O-) w -Pn-CR g 2 -Pn-O-(-R f -O-) q -R e - [In the formula, Pn is a 1,4-phenylene group, and each R e is the same or different and is a divalent hydrocarbon group having 2 to 8 carbon atoms, and each R f is the same or different and is an ethylene group or a propylene group, and each R g is the same or different and is a hydrogen atom or a methyl group, and each of the subscripts w and q is a positive integer in the range of 3 to 30]. Examples of such units can be given.

[0036] For the purposes of this application, "substituted" means that one or more hydrogen atoms in a hydrocarbon group are replaced by another substituent. Examples of such substituents include halogen atoms such as chlorine, fluorine, bromine and iodine; halogen atom-containing groups such as chloromethyl group, perfluorobutyl group, trifluoroethyl group, and nonafluorohexyl group; oxygen atom; oxygen atom-containing groups such as (meth)acrylic group and carboxyl group; nitrogen atom; nitrogen atom-containing groups such as amino functional group, amide functional group, and cyano functional group; sulfur atom; and sulfur atom-containing groups such as mercapto group, but are not limited thereto.

[0037] The composition also contains a crosslinking agent (ii). The crosslinking agent (ii) used herein is generally a silyl-functional molecule having at least two silyl groups, each silyl group having a viscosity of ≤1000 mPa·s at 25°C, provided that its viscosity is at least 75% of the viscosity of (i), or having a viscosity of ≤1000 mPa·s at 25°C, provided that its viscosity is at least 90% of the viscosity of polymer (i), or having a viscosity of ≤1000 mPa·s at 25°C, provided that its viscosity is the same as or greater than the viscosity of polymer (i), and containing at least two hydrolyzable groups.

[0038] For the disclosure of this specification, a silyl-functional molecule is a silyl-functional molecule containing two or more silyl groups, and each silyl group contains at least two hydrolyzable groups. Thus, a disilyl-functional molecule contains two silicon atoms each having at least one hydrolyzable group, and these silicon atoms are separated by an organic or siloxane polymer backbone. Typically, the silyl groups on the disilyl-functional molecule may be end groups. The polymer backbone may be a polymer chain.

[0039] To avoid misunderstanding, the crosslinking agent is not a disilane in which two silicon atoms are directly bonded to each other.

[0040] Examples of the hydrolyzable groups on the silyl group include acyloxy groups (e.g., acetoxy group, octanoyloxy group, and benzoyloxy group); ketoximino groups (e.g., dimethylketoximo group and isobutylketoximino group); alkoxy groups (e.g., methoxy group, ethoxy group, and propoxy group), and alkenyloxy groups (e.g., isopropenyloxy group and 1-ethyl-2-methylvinyloxy group). In a preferred embodiment, each hydrolyzable group is an alkoxy group.

[0041] In one embodiment, the crosslinking agent (ii) is a silyl-functional molecule having at least two silyl groups, each silyl group having two or three hydrolyzable groups, or each silyl group having at least two hydrolyzable groups, or each silyl group having three hydrolyzable groups. In one embodiment, each silyl group contains three alkoxy groups having 1 to 6 carbons, or three alkoxy groups selected from methoxy and / or ethoxy, or three methoxy groups. The above crosslinking agent (ii) may further contain a silyl-functional molecule having at least two silyl groups, and at least one silyl group contains one hydrolyzable group.

[0042] The silyl (e.g., disilyl) functional crosslinking agent (ii) may have a siloxane or organic polymer backbone. Suitable polymer crosslinking agents (ii) may have a polymer backbone chemical structure similar to the polymer chain A represented by the above formula (1). In the case of such siloxane or organic-based crosslinking agents, their molecular structure may be linear, branched, cyclic or macromolecular, i.e., the silicone or organic polymer chain having alkoxy functional end groups includes polydimethylsiloxane having at least one trialkoxy end, and the alkoxy group may be a methoxy group or an ethoxy group.

[0043] Accordingly, the terminal silyl group is -R a Si(OR b ) 2 , -Si(OR b ) 3 , -R a 2 SiOR b or -(R a ) 2 Si-R c -SiR d p (OR b ) 3-p [wherein each R a independently represents a monovalent hydrocarbon group, for example, especially an alkyl group having 1 to 8 carbon atoms (preferably methyl), each R b and R d groups are independently alkyl groups having up to 6 carbon atoms, R c is a divalent hydrocarbon group that may be intervened by one or more siloxane spacers having up to 6 silicon atoms, and p is a value of 0, 1 or 2] and may have formulas such as. Typically, each terminal silyl group has 2 or 3 alkoxy groups. For example, each R a can be methyl, R c is an ethylene or propylene group, or an ethylene group, and p is 0, that is, -(Me) 2 Si-CH 2 -CH 2 -Si(OMe) 3 .

[0044] In one embodiment, the crosslinking agent (ii) is a disilyl-functional polymer, i.e., contains two silyl groups, each of which has the formula (4) (R 4 O) m (Y 1 ) 3-m -Si(CH 2 ) x -((NHCH 2 CH 2 ) t -Q(CH 2 ) x ) n -Si(OR 4 ) m (Y 1 ) 3-m (4) [wherein, R 4 is a C 1~10 alkyl group, Y 1 is an alkyl group containing 1 to 8 carbons, Q is a chemical group containing a heteroatom having a lone pair of electrons, for example, an amine, an N-alkylamine or a urea, each x is an integer from 1 to 6, t is 0 or 1, each m is independently 1, 2 or 3, and n is 0 or 1] and may be a polymer containing at least one hydrolyzable group such as those described by

[0045] Therefore, examples of the crosslinking agent (ii) include 1,6-bis(trimethoxysilyl)hexane (also known as hexamethoxydisilylhexane), bis(trialkoxysilylalkyl)amine, bis(dialkoxyalkylsilylalkyl)amine, bis(trialkoxysilylalkyl)N-alkylamine, bis(dialkoxyalkylsilylalkyl)N-alkylamine, bis(trialkoxysilylalkyl)urea, bis(dialkoxyalkylsilylalkyl)urea, bis(3-trimethoxysilylpropyl)amine, bis(3-triethoxysilylpropyl)amine, bis(4-trimethoxysilylbutyl)amine, bis(4-triethoxysilylbutyl)amine, bis(3-trimethoxysilylpropyl)N-methylamine, bis(3-triethoxysilylpropyl)N-methylamine, bis(4-trimethoxysilylbutyl)N-methylamine, bis(4-triethoxysilylbutyl)N-methylamine, bis(3-trimethoxysilylpropyl)urea, bis(3-triethoxysilylpropyl)urea, bis(4-trimethoxysilylbutyl)urea, bis(4-triethoxysilylbutyl)urea, bis(3-dimethoxymethylsilylpropyl)amine, bis(3-diethoxymethylsilylpropyl)amine, bis(4-dimethoxymethylsilylbutyl)amine, bis(4-diethoxymethylsilylbutyl)amine, bis(3-dimethoxymethylsilylpropyl)N-methylamine, bis(3-diethoxymethylsilylpropyl)N-methylamine, bis(4-dimethoxymethylsilylbutyl)N-methylamine, bis(4-diethoxymethylsilylbutyl)N-methylamine, bis(3-dimethoxymethylsilylpropyl)urea, bis(3-diethoxymethylsilylpropyl)urea, bis(4-dimethoxymethylsilylbutyl)urea, bis(4-diethoxymethylsilylbutyl)urea, bis(3-dimethoxyethylsilylpropyl)amine, bis(3-diethoxyethylsilylpropyl)amine, bis(4-dimethoxyethylsilylbutyl)amine, bis(4-diethoxyethylsilylbutyl)amine, bis(3-dimethoxyethylsilylpropyl)N-methylamine, bis(3-diethoxyethylsilylpropyl)N-methylamine,Bis(4-dimethoxyethylsilylbutyl)N-methylamine, bis(4-diethoxyethylsilylbutyl)N-methylamine, bis(3-dimethoxyethylsilylpropyl)urea, bis(3-diethoxyethylsilylpropyl)urea, bis(4-dimethoxyethylsilylbutyl)urea and / or Bis(4-diethoxyethylsilylbutyl)urea; bis(triethoxysilylpropyl)amine, bis(trimethoxysilylpropyl)amine, bis(trimethoxysilylpropyl)urea, bis(triethoxysilylpropyl)urea, bis(diethoxymethylsilylpropyl)N-methylamine; di- or trialkoxysilyl-terminated polydialkylsiloxane, di- or trialkoxysilyl-terminated polyarylalkylsiloxane, di- or trialkoxysilyl-terminated polypropylene oxide, polyurethane, polyacrylate; polyisobutylene; di- or triacetoxysilyl-terminated polydialkyl; polyarylalkylsiloxane; di- or trioximinosilyl-terminated polydialkyl; polyarylalkylsiloxane; di- or triacetonoxy-terminated polydialkyl or polyarylalkyl. The crosslinking agent (ii) used may include any combination of two or more of the above.

[0046] As shown above, the ratio of Si-OH groups to Si-alkoxy groups in the composition is 0.4:1 to 0.95:1, or alternatively 0.5:1 to 0.75:1.

[0047] The composition further comprises a condensation catalyst (iv) which increases the rate at which the composition cures. The catalyst selected will vary depending on the required cure rate. Titanate-based catalysts and / or zirconate-based catalysts may include compounds of the general formula Ti[OR 22 4 or Zr[OR 22 4 [wherein each R 22 may be the same or different and represents a monovalent, primary, secondary or tertiary aliphatic hydrocarbon group which may be linear or branched and have from 1 to 10 carbon atoms]. Optionally, the titanate may contain a partially unsaturated group. However, R 22 ​​Preferred examples include, but are not limited to, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a tertiary butyl group, and a branched secondary alkyl group such as a 2,4-dimethyl-3-pentyl group. Each R 22 When they are the same, preferably, R 22 is an isopropyl group, a branched secondary alkyl group or a tertiary alkyl group, particularly a tertiary butyl group. Suitable examples include, for example, tetra-n-butyl titanate, tetra-t-butyl titanate, tetra-t-butoxy titanate, tetraisopropoxy titanate, and diisopropoxydiethylacetoacetate titanate. Alternatively, the titanate may be chelated. Chelation may be by any suitable chelating agent such as alkyl acetylacetonate, for example methyl or ethyl acetylacetonate. Alternatively, the titanate may be a monoalkoxy titanate that provides three chelating agents, for example 2-propanolato, tris isooctadecanoato titanate.

[0048] In one embodiment, the catalyst is present in a molar amount that is at least 50% of the molar amount of water (i.e., moisture) cumulatively present in parts A and B of the composition from the filler(s) therein when measured according to ISO787-2:1981. Typically, most of the moisture is derived from the reinforcing filler and / or non-reinforcing filler.

[0049] The multi-component condensation-curing gel composition of the present specification further includes one or more reinforcing fillers and / or non-reinforcing fillers. One or more reinforcing fillers and / or non-reinforcing fillers (iv) can be water-containing fillers. For this application, the term water-containing means that the filler(s) has a moisture (i.e., water) content of >0.05 wt% when measured according to ISO787-2:1981. Optionally, using the test method of ISO787 2:1981, the quantitative amount of moisture (water) present in the filler can be determined by extraction of moisture (water) from a sample of the filler used in the composition of the present invention. To avoid misuse of terms, moisture is intended to mean water and does not include Si alkoxy groups or Si-bonded hydroxyl groups in any case considered otherwise.

[0050] Examples of the micronized reinforcing fillers include fumed silica and precipitated silica with a large surface area such as rice husk ash, and to some extent calcium carbonate. Examples of additional micronized non-reinforcing fillers include crushed quartz, diatomaceous earth, barium sulfate, iron oxide, titanium dioxide, carbon black, talc, wollastonite. Other fillers that may be used alone or in combination with the above fillers include carbon nanotubes, such as multi-walled carbon nanotubes, aluminite, hollow glass spheres, calcium sulfate (anhydrite), gypsum, calcium sulfate, magnesium carbonate, kaolin, aluminum trihydroxide, clays such as magnesium hydroxide (hydrotalcite), graphite, copper carbonate, such as malachite, nickel carbonate, such as zarachite, barium carbonate, such as witherite, and / or strontium carbonate, such as strontianite.

[0051] Further alternative fillers include aluminum oxide, silicates from the group consisting of the cancrinite group, the pectolite group; aluminosilicates; cyclic silicates; chain silicates; and layer silicates. The cancrinite group includes silicate minerals such as forsterite and Mg 2 SiO 4 but is not limited thereto. The pectolite group includes red pectolite; Mg3 Al 2 Si 3 O 12 ; emerald; and Ca 2 Al 2 Si 3 O 12 and the like, including but not limited to ground silicate minerals. Aluminosilicates include sillimanite; Al 2 SiO 5 ; mullite; 3Al 2 O 3 .2SiO 2 ; kyanite; and Al 2 SiO 5 and the like, including but not limited to ground silicate minerals.

[0052] The cyclic silicate group includes cordierite and Al 3 (Mg, Fe) 2 [Si 4 AlO 18 and the like, including but not limited to silicate ores. The chain silicate group includes ground silicate minerals such as wollastonite and Ca[SiO 3 and the like, including but not limited to.

[0053] Layered silicates include mica; K 2 AI 14 [Si 6 Al 2 O 20 .(OH) 4 ; chlorite; Al 4 [Si 8 O 20 .(OH) 4 ; talc, Mg 6 [Si 8 O 20 .(OH) 4 ; serpentine, such as asbestos; kaolinite; Al 4 [Si 4 O 10 .(OH) 8 ; and vermiculite and the like, including but not limited to silicate minerals. The filler can be the water-containing filler defined above.

[0054] The filler(s) may optionally be surface-treated with a treating agent. Treating agents and treatment methods are known in the art. Surface treatment of the filler is typically carried out using, for example, a fatty acid or a fatty acid ester such as stearate, or an organosilane, organosiloxane, or organosilazane, such as a hexaalkyldisilazane or a short-chain siloxane diol. Generally, the surface treatment makes the filler hydrophobic and thus facilitates the handling and availability of a homogeneous mixture with other components in the composition. Silanes, for example, R 7 e Si(OR 6 ) 4-e [wherein, R 7 is a substituted or unsubstituted monovalent hydrocarbon group having 6 to 20 carbon atoms, such as an alkyl group such as hexyl, octyl, dodecyl, tetradecyl, hexadecyl, and octadecyl, and an aralkyl group such as benzyl and phenylethyl, an alkyl group having 6 to 20 carbon atoms is preferred, R 6 is alkyl having 1 to 6 carbon atoms, and the letter e is 1, 2, or 3] can also be used as a treating agent for the filler.

[0055] Optional raw material Adhesion promoter Suitable adhesion promoters may include alkoxysilanes of the formula R 14 h Si(OR 15 ) (4-h) [wherein the subscript h is 1, 2, or 3, or h is 3]. Each R 14 is independently a monovalent organic functional group. R 14 is an epoxy functional group such as a glycidoxypropyl group or an (epoxycyclohexyl)ethyl group, an amino functional group such as an aminoethylaminopropyl group or an aminopropyl group, a methacryloxypropyl group, a mercapto functional group such as a mercaptopropyl group, or an unsaturated organic group. Each R 15 is independently an unsubstituted saturated hydrocarbon group having at least 1 carbon atom. R 15may have 1 to 4 carbon atoms, or 1 to 2 carbon atoms. R 15 Examples thereof include methyl, ethyl, n-propyl, and isopropyl.

[0056] Examples of suitable adhesion promoters include glycidoxypropyltrimethoxysilane, and combinations of glycidoxypropyltrimethoxysilane with aluminum chelates or zirconium chelates. Examples of adhesion promoters for hydrosilylation curable compositions can be found in U.S. Patent Nos. 4,087,585 and 5,194,649. The curable composition, if present, may contain 0.01 to 2% by weight, or 0.05 to 2% by weight, or 0.1 to 1% by weight of an adhesion promoter, based on the weight of the composition. Preferably, the hydrolysis rate of the adhesion promoter needs to be slower than that of the crosslinking agent so as to be advantageous for the diffusion of molecules to the substrate rather than their incorporation into the product network.

[0057] Additional fillers Thermal and / or electrically conductive fillers, such as metal fillers, and water-insoluble fusible fillers, or combinations thereof, may be present. Metal fillers can be utilized. Such fillers include metal particles and metal particles having a layer on the particle surface. These layers may be, for example, metal nitride layers or metal oxide layers on the particle surface. Examples of suitable metal fillers include particles of metals selected from the group consisting of aluminum, copper, gold, nickel, tin, silver, and combinations thereof, or particles of aluminum. Further examples of suitable metal fillers include particles of the above metals having on their surface a layer selected from the group consisting of aluminum nitride, aluminum oxide, copper oxide, nickel oxide, silver oxide, and combinations thereof. For example, the metal filler may include aluminum particles having an aluminum oxide layer on their surface.

[0058] The fusible filler may contain Bi, Ga, In, Sn, or an alloy thereof. The fusible filler may optionally further contain Ag, Au, Cd, Cu, Pb, Sb, Zn, or a combination thereof. Examples of suitable fusible fillers include Ga, In-Bi-Sn alloy, Sn-In-Zn alloy, Sn-In-Ag alloy, Sn-Ag-Bi alloy, Sn-Bi-Cu-Ag alloy, Sn-Ag-Cu-Sb alloy, Sn-Ag-Cu alloy, Sn-Ag alloy, Sn-Ag-Cu-Zn alloy, and combinations thereof. The fusible filler may have a melting point in the range of 50°C to 250°C, or alternatively 150°C to 225°C. The fusible filler may be a eutectic alloy, a non-eutectic alloy, or a pure metal. The fusible filler is commercially available.

[0059] The thermally conductive filler may be a single thermally conductive filler or a combination of two or more thermally conductive fillers that differ in at least one property such as particle shape, average particle size, particle size distribution, and type of filler. In some embodiments, a combination of a metal and an inorganic filler, such as a combination of aluminum and an aluminum oxide filler, a combination of aluminum and a zinc oxide filler, or a combination of aluminum, aluminum oxide, and zinc oxide fillers may be used. In other embodiments, it may be desirable to combine a first conductive filler having a larger average particle size and a second conductive filler having a smaller average particle size in a ratio that satisfies the closest packing theory distribution curve. As an example, two aluminum oxide preparations having different average particle sizes are mixed. In other embodiments, different thermally conductive filler materials of different sizes can be used, for example, a combination of aluminum oxide having a larger average particle size and zinc oxide having a smaller average particle size can be used. Alternatively, it may be desirable to use a combination of metal fillers such as a first aluminum having a larger average particle size and a second aluminum having a smaller average particle size. The use of a first filler having a larger average particle size and a second filler having a smaller average particle size than the first filler can improve the filling efficiency, reduce the viscosity, and enhance the heat transfer.

[0060] The shape of the thermally conductive filler particles is not particularly limited, but when they are circular or spherical particles, it is possible to prevent the viscosity from increasing to an undesirable level due to a high content of the thermally conductive filler in the composition. The average particle size of the thermally conductive filler depends on various factors, including the type of thermally conductive filler selected, the exact amount added to the curable composition, and the thickness of the joint portion of the device in which the cured product of the composition is used. In some cases, the thermally conductive filler may have an average particle size in the range of 0.1 micrometer to 80 micrometers, or 0.1 micrometer to 50 micrometers, or 0.1 micrometer to 10 micrometers. The additional optional filler can also be treated with the above treatment agent as needed.

[0061] Other optional additives include surfactants, fluxes, acid acceptors, and / or corrosion-resistant additives, and combinations thereof.

[0062] Suitable surfactants include silicone polyethers, ethylene oxide polymers, propylene oxide polymers, copolymers of ethylene oxide and propylene oxide, other nonionic surfactants, and combinations thereof. The composition may contain up to 0.05% by weight of the surfactant based on the weight of the composition.

[0063] Plasticizer The composition may contain a non-reactive silicone polymer that functions as a plasticizer. Such non-reactive silicone polymers are typically trialkylsilyl-terminated polydimethylsiloxanes having a viscosity of 200 to 2000 mPa·s at 25°C.

[0064] Flux The composition may contain a flux of up to 2% by weight based on the weight of the composition. Molecules containing chemically active functional groups such as carboxylic acids and amines can be used as the flux. Such fluxes include aliphatic acids such as succinic acid, abietic acid, oleic acid, and adipic acid; aromatic acids such as benzoic acid; aliphatic amines and their derivatives such as triethanolamine, hydrochlorides of amines, and hydrobromides of amines. Fluxes are known in the art and are commercially available.

[0065] Acid acceptor Suitable acid acceptors include magnesium oxide, calcium oxide, and combinations thereof. The composition may optionally contain an acid acceptor of up to 2% by weight based on the weight of the composition.

[0066] Corrosion inhibitor additives such as nitrogen / sulfur-containing heterocyclic compounds having a triazole structure, a thiadiazole structure, a benzotriazole structure, a mercaptothiozole structure, a mercaptobenzothiazole structure, or a benzimidazole structure.

[0067] As indicated above, the condensation curable composition is stored in a multi-component form, typically a two-component form, and the polymer (i), crosslinking agent (ii), and catalyst (iii) are not all stored together in the same component. Further, the filler (iv) and the catalyst (iii) are typically held separately with the filler (iv) mixed with the polymer (i). The two components of the composition may be mixed using any suitable standard two-component mixing device by a dynamic or static mixer, and the resulting mixture is optionally metered and dispensed from the device for use in the intended application. The two-component composition may include, for example, any one of the following options. 1) Stored in two parts, part A having the polymer (i) and the crosslinking agent (ii), and part B having the polymer (i) and the catalyst (iii), or 2) Stored in two parts, part A having the polymer (i) and the catalyst (iii), and part B having the crosslinking agent (ii), or 3) Stored in two parts: part A having a first polymer (i) and a crosslinking agent (ii), and part B having a second polymer (i) and a catalyst (iii); or 4) Stored in two parts: part A containing a polymer (i), and part B containing a crosslinking agent (ii) and a catalyst (iii). Typically, the filler (iv) is stored in the part that does not contain the catalyst.

[0068] Alternatively, the composition can be stored in three or more parts as needed. Additional additives are generally added to part A. While most, if not all, of the moisture in the composition is expected to be present in the water-containing filler, if any other raw materials, including optional raw materials, contain moisture (water) in any form, the amount of the catalyst is determined based on the total moisture content from all sources, and the value is the value measured according to ISO787-2:1981.

[0069] Also provided herein is a method for producing the gel material described above in this specification by mutually mixing and curing two parts of the composition. After mutual mixing in one embodiment, the condensation-curable gel composition can be applied onto a substrate using a suitable dispenser such as a curtain coater, spray device, die coater, dip coater, extrusion coater, knife coater, and screen coater, etc., to provide a coating on the substrate during gel formation. Then, the composition is cured.

[0070] The substrate may be an electrical, electronic, or optical component, and after pre-curing if necessary, it may be adapted to or onto, for example, electrical, electronic, or optical components. The compositions herein are adhesive to various substrates such as electrical or electronic components and / or members, especially metal substrates such as gold, silver, aluminum, copper, and electroless nickel, and polymer substrates such as FR4, nylon, polycarbonate, Lucite (polymethyl methacrylate, PMMA), polybutylene terephthalate (PBT), and liquid crystal polymers such as Xydar® available from Solvay Chemicals, Houston, Tex. 77098 USA.

[0071] Any suitable electrical or electronic component may be encapsulated with the cured gel material described above. The cured gel material herein can suppress the generation of air bubbles and cracks, and this shows good bonding to electrical or electronic components even under high-temperature conditions. Thus, the cured gel material of the present invention can be advantageously used in power devices used under high-temperature conditions, particularly power devices such as motor control, motor control for transportation, power generation systems, or space transportation systems. Such products are useful as embedding materials for electronics to reduce the impact of thermal cycles on sensitive components.

[0072] Another reason is that the cured gel material of the present invention has a certain degree of cold resistance in addition to the heat resistance required for Si-C semiconductor chips (for example, heat resistance exceeding 180 °C). Electronic articles are power modules, for example, particularly in power devices that require the ability to withstand rapid temperature differences, such as power conversion devices, inverters, boosters, traction control devices, industrial motor control devices, and one or more of the above-mentioned devices for power distribution and power transmission systems, and the durability and reliability of such power devices can be improved. This may be designed for use in optical and electronic applications, including microelectronics applications, macroelectronics applications, optoelectronics applications, and thermally conductive electronics applications, for example, for the production of thermally conductive adhesives. Furthermore, the cured gel material of the present invention may be transparent and, therefore, may optionally be suitable for use as an encapsulant for manufacturing optoelectronic devices that include an optical guide and at least one optical element, such as an encapsulant used to manufacture an optoelectronic device that includes an optical guide and at least one optical element. The optoelectronic device may include at least one optical element and a self-supporting optical guide, for example, a composite optical guide configured to transmit light when the light is emitted from one or more optical elements.

[0073] The cured gel material described herein may function as an optical encapsulant for encapsulating at least one optical element. The optical guide may also include a lens for controlling the direction of light emitted from at least one optical element, at least one electrical connector for conducting electricity to at least one optical element, or any combination of two or more or all of the aforementioned additional elements.

[0074] The electrical connector may independently be a wire, a tabbed article, or a ribbon, and can be manufactured from highly conductive metals such as Cu, Au, Ag, and alloys thereof. Such optoelectronic devices can be used to manufacture lighting fixtures (devices having at least one light element that is a light-emitting element). The lighting fixture may include any one of the optoelectronic devices of the foregoing embodiments and a power source for supplying power to at least one light element. The lighting fixture may also further include a lens for controlling the direction of light emitted from at least one light element and at least one electrical connector for conducting electricity to at least one light element.

[0075] The power source may be operably electrically connected to at least one light element via the electrical connector. Each of the above light-emitting devices may be a light-emitting diode (LED), a liquid crystal display (LCD), or any other light source. In the absence of a filler, the compositions described herein are transparent and / or optically clear and are thus particularly suitable for protecting LED and / or LCD lighting from the environment. Such materials, when used as encapsulants, have several significant advantages over commercially available products, namely, they have a sufficiently high light transmittance, degrade without substantial discoloration (i.e., yellowing), the composition before curing has a relatively low viscosity even after separate parts are mixed, which is designed to have rapid room-temperature curing, i.e., following its mixing, it cures from the interface of air and the sealant in the bulk of the composition, similar to most titanate-based catalysts, and importantly, adhesion to a variety of electrical substrates is observed regardless. Further, if crosslinking agent (ii) is used, the two-part composition may be mixed in a 1:1 ratio as described above. This is not as susceptible to inhibition or reverse reactions as in the case of Pt-based and tin-based catalysts, respectively.

[0076] Examples of such power devices that require heat resistance and cold resistance include motor control devices used in cold regions (e.g., general-purpose inverter control devices, servo motor control devices, machine tools or elevators, electric vehicles, hybrid cars, or motor control devices for railway transportation used in cold regions), power generation systems used in cold regions (e.g., solar, wind, or fuel cell generators), and space transportation systems used in space. Note that "cold region" refers to a region where the temperature is below 0°C.

[0077] Furthermore, the cured gel material is also effective for sealing electrical components or electronic components having a structure with a narrow space between electrodes, between electrical elements, or between an electrical element and a package within an electrical or electronic component, or having a structure where these structures cannot follow the expansion and contraction of the cured gel material. For example, the cured gel material can be used in electrical circuits or modules on which electrical elements such as semiconductor elements, capacitors, and resistors are mounted, that is, various sensors such as pressure sensors generally sealed or filled with the cured gel material, and ignition devices and regulators of automobiles.

[0078] Electronic components can be defined as chips (e.g., silicon chips or silicon carbide chips), one or more wires, one or more sensors, one or more electrodes, integrated circuits (ICs) (e.g., hybrid ICs), power devices, insulated gate bipolar transistors (IGBTs), rectifiers (e.g., Schottky diodes, PiN diodes, integrated PiN / Schottky (MPS) rectifiers, and junction barrier diodes), bipolar junction transistors (BJTs), thyristors, metal oxide field effect transistors (MOSFETs), high electron mobility transistors (HEMTs), static induction transistors (SITs), electric power transistors, etc.

[0079] The electronic article can include electronic components and a first layer. The first layer is not particularly limited and can be a semiconductor, dielectric, metal, plastic, carbon fiber mesh, metal foil, perforated metal foil (mesh), filled or unfilled plastic film (e.g., polyamide sheet, polyimide sheet, polyethylene naphthalate sheet, polyethylene terephthalate polyester sheet, polysulfone sheet, polyetherimide sheet, or polyphenylene sulfide sheet), or a woven or non-woven fabric substrate (e.g., glass fiber cloth, glass fiber mesh, or aramid paper). Alternatively, the first layer may be further defined as a semiconductor and / or dielectric film.

[0080] The cured gel material may be sandwiched between the electronic component and the first layer, and / or disposed on the first layer, or in direct contact with the first layer, and / or disposed on the electronic component, or in direct contact with the electronic component. When the cured gel material is disposed on the first layer or in direct contact with the first layer, the cured gel material may be further disposed on the electronic component, but may include one or more layers or structures between the cured gel material and the electronic component.

[0081] Similarly, the composition may also contain light-scattering particles such as TiO 2 and silica, which are considered to have a great effect on the encapsulation of LED lighting.

[0082] The article may be a power electronic article, e.g., an electronic component provided with a material composition thereon, whereby the electronic component is either partially or completely encapsulated by the cured material. Alternatively, the electronic article may be an integrated circuit (IC) or a light-emitting diode (LED) system, or a printed circuit board (PCB).

Example

[0083] The following provides details of the raw materials listed in Tables 1 and 4 below. The accelerator 1 is a mixture (by weight) of 53.5% methyltrimethoxysilane, 27.4% 3-glycidoxypropyltrimethoxysilane, and 21.8% pre-condensed 3-aminopropyltriethoxysilane, The filler 1 was untreated quartz sold under the trademark of Sebelco® 708 Quartz having a particle size of 7 - 8 μm. The moisture content of Sebelco® 708 Quartz was about 0.24% by weight as measured according to ISO787-2:1981, The filler 2 was untreated quartz sold under the trademark of Sikron® SF600 Quartz having a particle size of about 3 μm. The moisture content of Sikron SF600 was about 0.24% by weight as measured according to ISO787-2:1981. The conductive filler used was commercially available aluminum trihydroxide sold under the trade name of HUAYA® LA4 by Foshan Huaya Superfine Powder Co., Ltd. The conductive filler was used untreated and had a particle size of 15 - 17 μm, a moisture content of ≤0.4% by weight, and a pH of about 8.5. The crosslinking agent 1 is a - (Me) 2 Si-CH 2 -CH 2 -Si(OMe) 3 polydimethylsiloxane with a group at the end, The crosslinking agent 2 is a - (Me) 2 Si-CH 2 -CH 2 -Si(OMe) 3 polydimethylsiloxane with a group at the end.

[0084] All viscosity measurements were performed according to ASTM D4287-00 using a Brookfield. Unless otherwise specified, a DV-III Ultra Rheometer type cone / plate rheometer was used to rotate spindle number 3 at room temperature (about 25°C) and 100 rpm.

[0085] The terms "silanol", "hydroxysilyl", "SiOH", and silicon-bonded hydroxyl can be used interchangeably within the scope of the present invention to denote the condensation-curable silyl end groups of polymers having at least one hydroxyl functional group.

[0086] The terms "alkoxy" and "SiOR" can be used interchangeably within the scope of the present invention to denote the condensation-curable silyl end groups of polymers having at least one hydrolyzable functional group. The terms "SiOH / SiOR ratio" and "silanol / alkoxy group ratio" can be used interchangeably within the scope of the present invention.

[0087] The examples according to the disclosure of this specification were prepared as shown in Table 1.

[0088] The compositions specified above were prepared via the following process.

[0089] Part A The polymer(s) was mixed in a speed mixer at 2000 rpm for 30 seconds. Subsequently, the conductive filler and Filler 1 were introduced, and the composition was further mixed in the speed mixer at 2000 rpm for another 30 seconds.

[0090] Part B Crosslinking agent 1 was mixed with a suitable catalyst and, if present, an adhesion promoter. The components were mixed in a speed mixer at 2000 rpm for 2 × 30 seconds. The resulting mixture was used immediately or stored in a 300 mL cartridge prior to use to avoid moisture ingress. [Table 1]

[0091] Part A and Part B were mixed in the ratios shown in Table 2. The Si-OH:Si-OR ratio for each sample was provided as the viscosity values of each part before mixing and the viscosity value of the final composition after mixing Parts A and B.

[0092] A part and B part mixture The A part and the B part were mixed 4 times at 2000 rpm for 30 seconds in a speed mixer according to the weight ratio shown in Table 2 below. [Table 2]

[0093] Next, the obtained composition was cured and a series of physical property tests were conducted. (i) In the fluidity test, a small ball of the material (about 4.7 g) was placed on a glass plate without disturbance and left at room temperature and 50% relative humidity for 1 hour, and the fluidity of the sample was evaluated by analyzing the base circle formed by the resulting flow. A sample having a diameter measured to be ≧ 35 mm after 1 hour was regarded as having "good" fluidity. (ii) An uncured sample having a thickness of about 0.35 cm at 25 °C and 50% relative humidity was spread on a clean smooth surface, and the non-stick time was measured by periodically touching the surface of the sample with a fingertip until the sample no longer adhered to the fingertip. (iii) The inversion time was measured by filling a sample of the final composition after mixing into a standard-sized aluminum cup to a height of about 15 mm. Then, the sample was cured either at room temperature (about 25 °C) or at 65 °C. The cup was periodically inverted, or "turned over". The point in time when the composition was sufficiently cured so that there was no substantial movement of the cured composition during inversion was regarded as the inversion time and recorded. (iv) The Shore A hardness samples tested had a thickness of 10 mm and were cured at room temperature for 7 days before testing.

[0094] The results of the physical property tests of the examples are shown in Table 3 below. [Table 3]

[0095] It can be seen from Comparative Example 1 that it is necessary to include a filler that provides moisture to the bulk of the composition in order to produce an appropriate inversion time at room temperature.

[0096] A series of further comparative examples were prepared. These comparative examples were prepared according to the above process in the examples using the amounts shown in Table 4 below.

Table 4

[0097] Parts A and B of the comparative examples were mixed analogously as above for the examples in the amounts shown in Table 5 below. Again, the Si-OH:Si-OR ratio is provided as the viscosity value of each part before mixing and the viscosity value of the final composition after mixing parts A and B.

Table 5

[0098] The resulting compositions were then cured and a series of physical property tests were performed using the same process as used in the above examples.

Table 6

[0099] It can be seen that one or both of the inversion time and non-stick time of the comparative examples are significantly greater than those of the results in Table 3 above. Also, from Comparative Examples 1 and 5, it can be seen that the absence of a filler has an adverse effect on the results. This is presumably because, when present, the presence of moisture in the composition from the quartz is reduced.

Claims

1. A multi-component condensation curable gel composition comprising: (i) at least one condensation curable silyl-terminated siloxane polymer having at least two hydroxyl functional groups per molecule and a viscosity of ≤ 1000 mPa·s at 25°C; (ii) a crosslinking agent having a silicone polymer chain with at least two silyl groups, each silyl group having a viscosity of ≤ 1000 mPa·s at 25°C and the viscosity being at least 75% of the viscosity of (i), and containing at least two hydrolyzable groups; (iii) a condensation catalyst selected from the group consisting of titanates and zirconates; (iv) one or more reinforcing fillers and / or non-reinforcing fillers containing > 0.05 wt% water, (a) the catalyst (iii) and the filler (iv) are not stored together before curing; (b) the ratio of Si-OH groups:Si-hydrolyzable groups in the composition is 0.4:1 to 0.95:1, and upon curing; (c) a multi-component condensation curable gel composition having a non-stick time of ≤ 1 hour at 25°C and a reversal time of ≤ 3 hours at 25°C.

2. The multi-component condensation curable gel composition according to claim 1, wherein the crosslinking agent (ii) is a silicone polymer chain having alkoxy functional end groups.

3. The polymer (i) further comprises a polydiorganosiloxane having one silanol-containing end group and one non-reactive end group, and / or The crosslinking agent (ii) further comprises a silyl-functional molecule having at least two silyl groups, and at least one silyl group contains one hydrolyzable group, and / or Before application, the multi-component condensation curable gel composition is stored in two parts, a base part containing the polymer (i) and the filler (iv), and a curable part containing the crosslinking agent (ii) and the catalyst (iii), the multi-component condensation curable gel composition according to any one of claims 1 to 2.

4. The multi-component condensation curable gel composition according to any one of claims 1 to 3, further comprising one or more thermally and / or electrically conductive fillers.

5. The multi-component condensation curable gel composition according to any one of claims 1 to 4, further comprising one or more adhesion promoters in an amount of 0.1 wt% to 2 wt% of the total composition.

6. The multiple-part condensation-curing gel composition according to any one of claims 1 to 5, wherein when measured according to ISO 787-2:1981, the catalyst is present in a molar amount that is at least 50% of the molar amount of water (i.e., water) that is cumulatively present in the composition from the filler(s) therein.

7. The multiple-part condensation-curing gel composition according to any one of claims 1 to 6, wherein the crosslinking agent (ii) has a viscosity of ≤1000 mPa·s at 25°C, and the viscosity is at least 90% of the viscosity of the polymer (i).

8. A method for preparing a cured gel material from the multiple-part condensation-curing gel composition according to any one of claims 1 to 7, the method comprising mixing the multiple parts of the condensation-curing gel composition together, applying the resulting mixture onto a substrate, and curing it.

9. A cured gel material that is a reaction product of the multiple-part condensation-curing gel composition according to any one of claims 1 to 7, (a) the catalyst (iii) and the filler (iv) are not stored together before curing, (b) the molar ratio of Si-OH groups:Si-alkoxy groups in the composition is 0.4:1 to 0.95:1, (c) when cured, it has a non-stick time of ≤1 hour at 25°C and a reversal time of ≤3 hours at 25°C.

10. An electrical or electronic component encapsulated or embedded with the cured gel material according to claim 9, wherein the electrical or electronic component is a metal substrate selected from gold, silver, aluminum, copper, and electroless nickel, and / or a polymer substrate selected from FR4, nylon, polycarbonate, polymethyl methacrylate, polybutylene terephthalate, and liquid crystal polymer.

11. The electrical or electronic component according to claim 10, comprising a light-emitting device that constitutes one or more light-emitting diodes (LEDs) or a liquid crystal display (LCD).

12. The electrical or electronic component according to claim 10 or 11, selected from a chip, one or more wires, one or more sensors, one or more electrodes, an integrated circuit (IC), a power device, an insulated gate bipolar transistor (IGBT), a rectifier, a high electron mobility transistor (HEMT), a static induction transistor (SIT), or a power transistor.

13. Use of the composition according to any one of claims 1 to 7 as an encapsulant or embedding material for an electrical device and / or an electronic device, a photovoltaic module and / or a light-emitting diode.

14. Use of the cured gel material according to claim 9 as an encapsulant or embedding material for an electronic device, a photovoltaic module, and / or a light-emitting diode.

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