TWI780238B - One-part curable silicone composition - Google Patents

Abstract

The present invention relates to a one-part curable silicone composition comprising: (A) an organopolysiloxane having at least two silicon-bonded alkenyl groups per molecule; (B) an organohydrogenpolysiloxane having at least two silicon-bonded hydrogen atoms per molecule; (C) a platinum group metal base hydrosilylation catalyst; (D) an hydrosilylation reaction inhibitor; and (E) an acrylic and/or methacrylic compound. The one-part curable silicone composition exhibits good store stability and can cure at relatively low temperatures to form a cured product with good adhesion to various substrates.

Description

One-Part Curable Silicone Composition

The present invention relates to a one-part curable polysiloxane composition that can be cured at relatively low temperatures to form a cured product that has good adhesion to a variety of substrates.

Hydrosilylation-curable polysiloxane compositions form cured products having excellent characteristics such as weather resistance and heat resistance, and they cure particularly quickly by heating without generating by-products during curing, so these compositions are used Adhesives, sealants or coating agents for electrical/electronic equipment.

Examples of such curable silicone compositions include curable silicone compositions comprising: an organopolysiloxane having at least two silicon-bonded alkenyl groups per molecule, at least two and Organohydrogen polysiloxanes with silicon-bonded hydrogen atoms, hydrosilylation reaction catalysts, allyl ester compounds, nitro compounds, and adhesion promoters (see Patent Document 1); curable polysiloxane compositions, including: each Organopolysiloxanes having at least two alkenyl groups in the molecule, organopolysiloxanes having at least two silicon-bonded hydrogen atoms per molecule, hydrosilylation reaction catalysts and acid anhydrides having silicon-bonded alkoxy groups (see patent document 2); and a curable polysiloxane composition, including: an organopolysiloxane having at least two alkenyl groups per molecule, an organic polysiloxane comprising R ₃ SiO _1/2 units and SiO _4/2 units Silicone resin, wherein each R is independently a C ₁ -C ₁₀ monovalent hydrocarbon group or a C ₂ -C ₆ alkenyl group without aliphatic unsaturation, and the molar ratio of R ₃ SiO _1/2 / SiO _4/2 is 0.6 to 1.0, an organohydrogenpolysiloxane having at least three silicon-bonded hydrogen atoms per molecule, and a platinum group metal base catalyst (see Patent Document 3).

Such curable polysiloxane compositions are provided in two components, which are divided into an organopolysiloxane having silicon-bonded hydrogen atoms and a hydrosilylation catalyst to ensure storage stability. The two components must be mixed evenly. Therefore, if the mixing ratio of the two components should be changed or the two components are not sufficiently mixed, the inherent properties cannot be exhibited.

Usually, such curable polysiloxane compositions are cured at high temperatures, such as 100° C. or higher, so as to be sufficiently cured to form a cured product with good adhesion to the substrate. Therefore, curable polysiloxane compositions cannot be sufficiently cured at low temperatures such as 80° C. or lower, and even if they are cured, the cured products cannot be sufficiently adhered to the substrate.

Therefore, even though the curable polysiloxane composition described in each of Patent Documents 1 to 3 is a one-part formula, good storage stability in the one-part form and good adhesion of the cured product to various substrates are kept consistent Sexually difficult. Prior Art Documents Patent Documents

Patent Document 1: Japanese Patent Application Publication No. 2009-221312 A Patent Document 3: US Patent Application Publication No. 2012/0309921 A1 Patent Document 3: US Patent Application Publication No. 2016/0053148 A1

Technical Problem The object of the present invention is to provide a one-part curable polysiloxane composition which has good storage stability and forms a cured product exhibiting good adhesion to various substrates by curing at a relatively low temperature. solution to the problem

The one-part curable polysiloxane composition of the present invention comprises: (A) an organopolysiloxane having at least two silicon-bonded alkenyl groups per molecule; (B) an organopolysiloxane having at least two silicon-bonded alkenyl groups per molecule; Organohydrogenpolysiloxanes with bonded hydrogen atoms, wherein the content of silicon-bonded hydrogen atoms is at least 1% by mass of the component, in such an amount that per 1 mole of silicon-bonded The content of the bonded alkenyl group and the hydrogen atom bonded to silicon is 0.1 to 10 moles in this component; The amount of the platinum group metal is 1 to 200 ppm; (D) hydrosilylation reaction inhibitor, its amount is 0.1 to 1% by mass of the composition; and (E) acrylic acid and/or methacrylic acid compound, its The amount is 0.1 to 5% by mass of the composition.

Component (A) is preferably (A-1) a linear organopolysiloxane having at least two silicon-bonded alkenyl groups per molecule; (A-2) consisting of R ¹ ₃ SiO _1/2 units and The organopolysiloxane resin composed of SiO _4/2 units has a molar ratio (R ¹ ₃ SiO _1/2 units)/(SiO _4/2 units) of 0.6 to 1.7, wherein each R ¹ represents a A monovalent hydrocarbon group of 12 carbon atoms, provided that at least two R in each molecule are alkenyl groups having ² to 12 carbon atoms; or a mixture of components (A-1) and (A-2), and more Best is a mixture of components (A-1) and (A-2), wherein the content of component (A-1) is at least 10% by mass of the mixture of components (A-1) and (A-2) .

Component (D) preferably contains acetylenic alcohol and unsaturated carboxylic acid ester.

Component (E) is preferably 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, or methyl methacrylate.

The one-part curable polysiloxane composition of the present invention is preferably used as an adhesive, sealant or coating agent for electrical/electronic equipment. Invention effect

The one-part curable polysiloxane composition according to the present invention exhibits good storage stability and, by curing at a lower temperature, can form a cured product exhibiting good adhesion to various substrates.

<One-Part Curable Silicone Composition> The one-part curable silicone composition according to the present invention contains the above-mentioned components (A) to (E). Such one-part curable polysiloxane compositions exhibit good storage stability and, by curing at low temperatures, such as 80° C. or less, can form polysiloxanes that exhibit good adhesion to substrates they contact during curing. cured product. Each of the components will be described in detail below.

Component (A) is an organopolysiloxane having at least two silicon-bonded alkenyl groups per molecule. Examples of alkenyl groups include alkenyl groups having 2 to 12 carbon atoms, such as vinyl, allyl, butenyl, pentenyl, hexenyl, heptenyl, octenyl, nonenyl, decene group, undecenyl group and dodecenyl group, among which vinyl group is preferred. In addition, examples of groups bonded to silicon atoms other than alkenyl groups in component (A) include alkyl groups having 1 to 12 carbon atoms, such as methyl, ethyl, propyl, isopropyl, Butyl, isobutyl, tert-butyl, pentyl, neopentyl, hexyl, cyclohexyl, heptyl, octyl, nonyl, decyl, undecyl, and dodecyl; with 6 to 20 Aryl groups of carbon atoms, such as phenyl, tolyl, xylyl and naphthyl; Aralkyl groups having 7 to 20 carbon atoms, such as benzyl, phenethyl and phenylpropyl; and in these groups A group in which some or all of the hydrogen atoms are substituted with a halogen atom such as a fluorine atom, chlorine atom, or bromine atom. Also, the silicon atom in component (A) may have a small amount of hydroxyl or alkoxy such as methoxy or ethoxy within the range that does not impair the object of the present invention.

Examples of the molecular structure of component (A) include a linear structure, a partially branched linear structure, a branched structure, a cyclic structure, and a three-dimensional network structure. Component (A) may be one type of organopolysiloxane having these molecular structures, or may be a mixture of two or more types of organopolysiloxanes having these molecular structures.

Such component (A) is preferably (A-1) linear organopolysiloxane; (A-2) organopolysiloxane resin; or components (A-1) and (A-2) mixture.

Examples of such component (A-1) include dimethyl polysiloxane capped at both ends of the molecule with dimethylvinylsiloxy, Dimethylsiloxane-methylvinylsiloxane copolymer at the end, dimethylsiloxane-methylphenylsiloxane copolymer capped at both ends of the molecule with dimethylvinylsiloxane , methyl phenyl polysiloxane terminated with dimethyl vinylsiloxy at both ends of the molecule, dimethylsiloxane-methyl polysiloxane terminated with trimethylsiloxy at both ends of the molecule Vinyl siloxane copolymer, dimethyl siloxane-methyl vinyl siloxane-methyl phenyl siloxane copolymer capped at both ends of the molecule with trimethylsiloxy group, dimethyl siloxane Dimethyl polysiloxane capped at both ends of the molecule with vinyl vinyl siloxy and capped with dimethyl vinyl siloxy at one end and dimethyl hydroxy siloxy at the other end A mixture of dimethylpolysiloxane, dimethylpolysiloxane endcapped with dimethylvinylsiloxy at both ends of the molecule and dimethylhydroxysiloxy endcapped at both ends of the molecule A mixture of dimethyl polysiloxane, and a mixture of two or more thereof.

Component (A-2) is an organopolysiloxane resin composed of R ¹ ₃ SiO _1/2 units and SiO _4/2 units. In this formula, each R ¹ represents a monovalent hydrocarbon group having 1 to 12 carbon atoms. Examples of monovalent hydrocarbon groups are methyl, ethyl, propyl, or similar alkyl groups; vinyl, allyl, butenyl, pentenyl, hexenyl, or similar alkenyl groups; phenyl, tolyl, di tolyl or similar aryl; benzyl, phenethyl or similar aralkyl; and 3-chloropropyl, 3,3,3-trifluoropropyl, or similar halogenated alkyl. However, at least two R ¹ per molecule are alkenyl. Component (A-2) may have residual silanol groups resulting from the hydrolysis of the reactive silanes used to prepare component (A-2).

The molar ratio of R ¹ ₃ SiO _1/2 units to SiO _4/2 units in component (A-2) is in the range of 0.6 to 1.7, preferably in the range of 0.6 to 1.5. This is because when the molar ratio is greater than or equal to the lower limit of the above range, the solubility of the component to other components is improved, and when the molar ratio is less than or equal to the upper limit of the above range, the mechanical properties of the cured product are improved .

When the mixture of component (A-1) and component (A-2) is used as component (A), the content of component (A-1) is preferably component (A-1) and (A- 2) At least 10% by mass or at least 40% by mass of the total amount, because the resulting composition has good handleability. In addition, the content of component (A-1) is preferably at most 90% by mass of the total amount of components (A-1) and (A-2), because the mechanical properties of the cured product are good.

Component (B) is an organohydrogenpolysiloxane having at least two silicon-bonded hydrogen atoms per molecule, wherein the content of silicon-bonded hydrogen atoms is at least 1% by mass of the component. This is because when the content of hydrogen atoms bonded to silicon is greater than or equal to the lower limit of the above range, the curability of the composition is improved. Examples of groups bonded to silicon atoms other than hydrogen atoms in component (B) include alkyl groups having 1 to 12 carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl, Isobutyl, tert-butyl, pentyl, neopentyl, hexyl, cyclohexyl, heptyl, octyl, nonyl, decyl, undecyl, and dodecyl; those having 6 to 20 carbon atoms Aryl groups such as phenyl, tolyl, xylyl and naphthyl; aralkyl groups having 7 to 20 carbon atoms such as benzyl, phenethyl and phenylpropyl; and some or all of these groups A hydrogen atom group is substituted with a halogen atom (such as a fluorine atom, a chlorine atom, or a bromine atom). Also, the silicon atom in component (B) may have a small amount of hydroxyl or alkoxy such as methoxy or ethoxy within the range not impairing the object of the present invention.

Examples of the molecular structure of component (B) include linear, partially branched linear, branched, cyclic, and three-dimensional network structures, and the molecular structure is preferably partially branched linear, branched, or three-dimensional grid.

Examples of such component (B) include methylhydropolysiloxane capped with trimethylsiloxy at both molecular terminals, dimethylhydropolysiloxane capped with trimethylsiloxy at both molecular terminals, Silicone-methylhydrogensiloxane copolymer, dimethylpolysiloxane terminated with dimethylhydrogensiloxy at both molecular ends, dimethylhydrogensiloxane at both molecular ends Dimethylsiloxane-methylhydrogensiloxane copolymer terminated with trimethylsiloxane groups, methylhydrogensiloxane-diphenylsiloxane copolymer terminated with trimethylsiloxy groups at both molecular ends , Methylhydrosiloxane-diphenylsiloxane-dimethylsiloxane copolymer terminated with trimethylsiloxy at both molecular ends, composed of (CH ₃ ) ₂ HSiO _1/2 units Copolymers composed of and SiO _4/2 units, copolymers composed of (CH ₃ ) ₂ HSiO _1/2 units, SiO _4/2 units and (C ₆ H ₅ )SiO _3/2 units, and two or more Various mixtures.

Component (B) is present in an amount such that the content of silicon-bonded hydrogen atoms in the component is 0.1 to 10 moles, less Preferably 0.5 to 5 moles. This is because when the content of component (B) is less than or equal to the upper limit of the above range, the mechanical properties of the cured product are good, and when the content of component (B) is greater than or equal to the lower limit of the above range, the curability of the composition good.

Component (C) is a platinum group metal alkali hydrosilation catalyst used to accelerate the curing of the composition of the present invention. Examples of component (C) include platinum group element catalysts and platinum group element compound catalysts, and specific examples include platinum-based catalysts, rhodium-based catalysts, palladium-based catalysts, and combinations of at least two types thereof. In particular, platinum-based catalysts are preferred because they significantly accelerate the curing of the compositions of the present invention. Examples of these platinum-based catalysts include finely powdered platinum; platinum black; chloroplatinic acid, alcohol-modified chloroplatinic acid; chloroplatinic acid/diene complexes; platinum/olefin complexes; platinum/carbonyl complexes , such as platinum bis(acetoacetate) and platinum bis(acetylacetonate); chloroplatinic acid/alkenylsiloxane complexes such as chloroplatinum acid/divinyltetramethyldisiloxane complexes, and chloroplatinic acid/tetravinyltetramethylcyclotetrasiloxane complexes; platinum/alkenylsiloxane complexes such as platinum/ Divinyltetramethyldisiloxane complexes, and platinum/tetravinyltetramethylcyclotetrasiloxane complexes; complexes of chloroplatinic acid and ethynyl alcohol; and two or more thereof mixture. In particular, platinum-alkenylsiloxane complexes are preferred because they accelerate the curing of the compositions of the present invention.

Examples of alkenylsiloxanes for platinum-alkenylsiloxane complexes include 1,3-divinyl-1,1,3,3-tetramethyldisiloxane, 1,3,5 , 7-Tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane, alkenyl siloxane oligomers, wherein some of the methyl groups of these alkenyl siloxanes are replaced by ethyl, phenyl and other substitutions, and alkenyl siloxane oligomers, wherein the vinyl groups of these alkenyl siloxanes are substituted by allyl, hexenyl, etc. In particular, 1,3-divinyl-1,1,3,3-tetramethyldisiloxane is preferred because the resulting platinum-alkenylsiloxane complex has good stability.

In order to increase the stability of platinum-alkenylsiloxane complexes, it is preferable to dissolve these platinum-alkenylsiloxane complexes in alkenylsiloxane oligomers, such as 1,3-divinyl -1,1,3,3-tetramethyldisiloxane, 1,3-diallyl-1,1,3,3-tetramethyldisiloxane, 1,3-divinyl- 1,3-Dimethyl-1,3-diphenyldisiloxane, 1,3-divinyl-1,1,3,3-tetraphenyldisiloxane, or 1,3,5 , 7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane, or organosiloxane oligomers, such as dimethylsiloxane oligomers, particularly preferably the compounds dissolved in alkenyl siloxane oligomers.

The content of the component (C) in this component is 1 to 200 ppm of the platinum group metal in mass units relative to the composition. Specifically, the content is preferably such that the content of the platinum group metal in component (C) is in the range of 0.01 to 150 ppm, in the range of 0.01 to 100 ppm, in mass units relative to the present composition, Or in the range of 0.1 to 100 ppm. This is because when the content of component (C) is greater than or equal to the lower limit of the above-mentioned range, the curability of the composition is good, and when the content of component (C) is less than or equal to the upper limit of the above-mentioned range, the coloring of the cured product is reduced inhibition.

Component (D) is a hydrosilylation reaction inhibitor to prolong pot life at ambient temperature and improve storage stability. Examples of component (D) include acetylenic alcohols such as 1-ethynyl-cyclohex-1-ol, 2-methyl-3-butyn-2-ol, 2-phenyl-3-butyn-2-ol alcohols, 2-ethynyl-isopropan-2-ol, 2-ethynyl-butan-2-ol, and 3,5-dimethyl-1-hexyn-3-ol; silylated ethynyl alcohols such as Trimethyl(3,5-Dimethyl-1-hexyne-3-oxyl)silane, Dimethylbis(3-methyl-1-butyne-oxyl)silane, Methylvinylbis( 3-methyl-1-butyne-3)-oxy)silane, and ((1,1-dimethyl-2-propynyl)oxy)trimethylsilane; unsaturated carboxylic acid esters such as cis Diallyl fumarate, dimethyl maleate, diethyl fumarate, diallyl fumarate, and bis(2-methoxymaleate) -1-methyl ethyl ester), monooctyl maleate, monoisooctyl maleate, monoallyl maleate, monomethyl maleate, trans-butene Monoethyl diacid, monoallyl fumarate, and 2-methoxy-1-methylethyl maleate; enynes such as 2-isobutyl-1-butene -3-yne, 3,5-dimethyl-3-hexene-1-yne, 3-methyl-3-pentene-1-yne, 3-methyl-3-hexene-1-yne, 1-ethynylcyclohexene, 3-ethyl-3-buten-1-yne, and 3-phenyl-3-buten-1-yne; and mixtures of two or more thereof. In particular, a mixture of acetylenic alcohol and unsaturated carboxylic acid ester is preferred in order to prevent surface wrinkles of the cured product.

The content of component (D) in this component is an amount of 0.1 to 1000 ppm relative to the composition in mass units. Specifically, the content in the component is preferably in an amount of 1 to 1000 ppm or 10 to 500 ppm in mass units relative to the composition of the present invention. This is because when the content of component (D) is greater than or equal to the lower limit of the above-mentioned range, the storage stability of the composition is good, and when the content of component (D) is less than or equal to the upper limit of the above-mentioned range, the composition Good curability at low temperature.

Component (E) is an acrylic and/or methacrylic compound to improve the adhesion of the composition to various substrates during low-temperature curing. Examples of such component (E) include silane compounds containing acrylic and/or methacrylic groups, such as 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyl Dimethoxysilane, 3-methacryloxypropyltriethoxysilane; and acrylic and/or methacrylic monomers such as methyl acrylate, ethyl acrylate, methyl methacrylate. In particular, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane and methyl methacrylate are preferred because of their adhesion to various engineering plastics Department of good.

The content of component (E) is 0.1 to 5% by mass of the composition, preferably within the range of 0.1 to 3% by mass, or within the range of 0.5 to 3% by mass. This is because when the content of component (E) is greater than or equal to the lower limit of the above-mentioned range, the adhesiveness of the cured product is good, and when the content of component (E) is less than or equal to the upper limit of the above-mentioned range, this composition can Good curing properties.

Typical additives include, but are not limited to, fillers, pigments, dyes, flame retardants, and thermal and/or UV light stabilizers to enhance the physical properties of the cured product.

The one-part curable silicone compositions of the present invention can be prepared by combining all ingredients at room temperature. Any of the mixing techniques and devices described in the prior art can be used for this purpose. The particular apparatus used will be dictated by the viscosity of the ingredients and the final curable composition. It may be desirable to cool the ingredients during mixing to avoid premature solidification.

The one-part curable polysiloxane compositions of the present invention are particularly useful as adhesives, sealants or coatings for heat-sensitive electrical/electronic devices. example

The one-part curable silicone composition of the present invention will now be described by way of practical examples and comparative examples. In this formula, Me and Vi represent a methyl group and a vinyl group, respectively. Note that the viscosity is a value obtained at 25°C. The properties of the one-part curable silicone compositions were evaluated as follows. ＜Viscosity＞

Viscosity is measured using a rotational viscometer such as a Brookfield Synchronous Viscometer or a Wells-Brookfield 52 Cone/Plate Viscometer. Since almost all measured materials are non-Newtonian in nature, there should be no correlation between results obtained using different axes (cones) or velocities. Results are usually reported in centipoise. Viscosity was measured at 0.5 and 5.0 rpm for 2 minutes. The method is based on ASTM D 4287 for cones/plates. ＜Curing condition＞

The curing conditions for low temperature curable silicone adhesives are basically applied in an oven using 80°C for 1 hour. <DSC Tc>

Differential Scanning Calorimetry (DSC) is a technique for studying the thermal behavior of materials as they undergo physical and chemical changes in heating, cooling or isothermal modes. Results are reported as annotated thermograms containing features identified by the analyst. With a DSC instrument, the heat flow or enthalpy change associated with the transition can be measured by accepting calibrations from different sources. ＜Hardness of cured product＞

A cured product having a thickness of 6 mm was obtained by curing the low-temperature curable silicone composition at 80° C. for 1 hour in an oven. Then, the hardness of the cured product was measured by using the Shore A hardness according to ASTM D 2240 "Standard Test Method for Rubber Property - Durometer Hardness". <MDR>

The rheological properties and curing characteristics of vulcanized elastomer materials were determined using a Monsanto moving die rheometer. Measure the torque required to oscillate the die through a small arc. Torque s' of displacement increases with vulcanization of the elastomer and is automatically plotted and/or calculated by preset computerized conditions, eg, lb-inches versus time. The curve varies with test temperature and properties of cured and uncured elastomers, plasticity, scorch time, hardness, cure rate and modulus. The instrument can also measure non-displacement torque s'' (loss modulus) and calculate tanδ (ratio of s''/s'). The temperature set for MDR measurement was applied at 80°C for 1 hour, and the curing curve was checked by observing time. The method is based on ASTM D 5289-92. ＜Applicable period＞

Pot life is described as the time required for a system to double its viscosity after catalysis. This is considered normal available business hours. The test is designed for any material that cures at room temperature on which viscosity measurements can be made. If a minimum time is specified, a "pass/fail" result may be reported. Cure rate is described as the time required to achieve a specified viscosity. The pot life index can be reported by dividing the final specified viscosity by the original viscosity. Other reporting modes can be specified. For pot life measurements, a Brookfield viscometer with 52 cone and plate was used. The procedure is based on ASTM D 1824. ＜Surface wrinkles＞

Surface wrinkles were checked with visible wrinkles on the cured adhesive samples, and the curing conditions for the low temperature curable silicone adhesive were essentially applied in an oven using 80°C for 1 hour. ＜Lap shear strength＞

The adhesive properties of the primer, adhesive and/or sealant are determined by measuring the amount of stretch required to separate the bilayer laminate by shear. Results are reported in pounds per square inch unless otherwise noted. Evaluate the amount of adhesive or cohesive failure by inspecting the exposed surface of the substrate. The procedure is based on ASTM D 816. Lap shear test samples were prepared by using Al plates, and the samples were cured in an oven at 80 °C for 1 hour. ＜Adhesive failure mode - cohesive failure＞

Adhesion of uncured or low-strength materials to the substrate is determined by preparing a sandwich of material between two sheets of substrate, manually pulling the substrate apart, and visually evaluating the area of cohesive failure. Three configurations can be used to make the sandwich. The average of three separate interlayers was recorded to be close to 5%. Standard substrates can be specified. A 100% cohesive failure indicates that the material has good adhesion. The percentage of cohesive failures can be evaluated and reported. <Embodiment Examples 1 to 11 and Comparative Example 1>

The following components were uniformly mixed according to the compositions (parts by mass) shown in Tables 1 to 3 to prepare the one-part curable polysiloxane compositions of Embodiment Examples 1 to 11 and Comparative Example 1. In the formula, Vi represents a vinyl group, and Me represents a methyl group. In addition, in Tables 1 to 3, "SiH/Vi" represents the amount of silicon bonded in component (B) per 1 mole of total vinyl groups in component (A) in the one-part curable polysiloxane composition. The total number of moles of hydrogen atoms in the junction.

The following components were used as component (A). Component (a-1): a mixture having a vinyl content of 0.56% by mass, composed of 74% by mass of dimethylpolysiloxane terminated with dimethylvinylsiloxy groups at both molecular ends, having 40,000 Viscosity in mPa·s, and composition with 0.09 mass % vinyl content, and 26 mass % organopolysiloxane resin with 1.89 mass % vinyl content, the organopolysiloxane resin is represented by the average unit formula: ( Me ₂ ViSiO _1/2 ) _0.05 (Me ₃ SiO _1/2 ) _0.47 (SiO _4/2 ) _0.48 Component (a-2): Dimethylvinylsiloxy-capped at both molecular ends Methylpolysiloxane has a viscosity of 10,000 mPa·s and a vinyl content of 0.14% by mass. Component (a-3): dimethylpolysiloxane terminated with dimethylvinylsiloxy groups at both ends of the molecule, with a viscosity of 2,000 mPa·s and a vinyl content of 0.23% by mass.

The following components were used as component (B). Component (b-1): Methylhydropolysiloxane terminated with trimethylsiloxy groups at both molecular ends, having a viscosity of 20 mPa·s and 1.56% by mass of silicon-bonded hydrogen atomic content.

The following components were used as component (C). Component (c-1): 1,3-divinyl-1,1,3-tetramethyldisiloxane complex of platinum 1,3-divinyl-1,1,3 , 3-tetramethyldisiloxane solution (platinum metal content = about 8,800 ppm)

The following components were used as component (D). Component (d-1): 1-ethynylcyclohexan-1-ol Component (d-2): bis(2-methoxy-1-methylethyl maleate)

The following components were used as component (E). Component (e-1): 3-methacryloxypropyltrimethoxysilane Component (e-2): methyl methacrylate Component (e-3): hydroxypropyl acrylate component ( e-4): 2-Hydroxyethyl methacrylate Component (e-5): Glycidyl methacrylate Component (e-6): 3-Glycidoxypropyltrimethoxysilane

[表2]

[表3]

＜實施實例13＞The following components were used as optional components. Component (f-1): Carbon black powder (the carbon black powder was added as a masterbatch consisting of 50% by mass of the carbon black powder and 50% by mass of the component (a-3)). [Table 1]

[Table 2]

[table 3]

＜Example 13＞

The one-part curable polysiloxane composition prepared in Example 8 was heated at 80° C. for 30 minutes, cured on the substrates shown in Table 4, and the adhesive properties were evaluated as follows. ＜Adhesive properties＞

產業利用性Pull-off adhesion test can be one of the alternative adhesion test methods. The test method is described below. The procedure of the pull-off adhesion test is as follows. First, the prepared Teflon zig was placed on the metal substrate, and second, the potting adhesive material was filled into 6 mm diameter Teflon holes, and then the adhesive material was cured in an oven at 80 °C for 1 hour. Third, the Teflon zig was removed from the substrate, followed by a pull-off test by manual measurement. A certain degree of adhesive performance is judged to be present if cohesive failure on the substrate (glass, Al, EMC, PCB, PET) is fully observed. [Table 4]

Industrial utilization

The one-part curable polysiloxane compositions of the present invention have excellent storage stability, require no mixing prior to use, cure at relatively low temperatures and form exhibiting good adhesion to a variety of substrates that come into contact during curing cured product. Therefore, it is ideally used as an adhesive, coating agent or sealant for electric/electronic equipment.

Claims (5)

A one-part curable polysiloxane composition comprising: (A) an organopolysiloxane having at least two silicon-bonded alkenyl groups per molecule; (B) an organopolysiloxane having at least two silicon-bonded alkenyl groups per molecule Organohydrogenpolysiloxanes containing hydrogen atoms, wherein the content of silicon-bonded hydrogen atoms is at least 1% by mass of the component, in an amount such that for every 1 mole of silicon-bonded in component (A) The alkenyl group, the content of hydrogen atoms bonded to silicon is 0.1 to 10 moles in this component; (C) platinum group metal alkali hydrosilation catalyst, relative to the composition in mass units, this component The amount of the platinum group metal is 1 to 200ppm; (D) hydrosilylation inhibitor, the amount is 0.1 to 1% by mass of the composition; and (E) acrylic acid and/or methacrylic acid compound, the amount is 0.1 to 5% by mass of the composition, wherein component (D) contains acetylenic alcohol and unsaturated carboxylic acid ester. The one-part curable polysiloxane composition according to claim 1, wherein component (A) is: (A-1) a linear organopolysiloxane having at least two silicon-bonded alkenyl groups per molecule ; (A-2) organopolysiloxane resin composed of R ¹ ₃ SiO _1/2 unit and SiO _4/2 unit, its molar ratio (R ¹ ₃ SiO _1/2 unit)/(SiO _{4/ 2} units) are 0.6 to 1.7, wherein each R ¹ represents a monovalent hydrocarbon group with 1 to 12 carbon atoms, but at least two R ¹ are alkenyl groups with 2 to 12 carbon atoms in each molecule; or the component ( A mixture of A-1) and (A-2). Such as the one-part curable polysiloxane composition of claim 2, wherein component (A) is a mixture of the components (A-1) and (A-2), wherein the content of component (A-1) It is at least 10% by mass of the mixture of the components (A-1) and (A-2). The one-part curable silicone composition according to any one of claims 1 to 3, wherein component (E) is 3-methacryloxypropyl trimethoxysilane, 3-methacryl Oxypropyl triethoxysilane, or methyl methacrylate. The one-part curable polysiloxane composition according to any one of claims 1 to 3, wherein the composition is an adhesive, sealant or coating agent for electrical/electronic equipment.