Curable resin composition and adhesive material

Abstract

The present invention provides a curable resin composition which is excellent in terms of curability and adhesiveness without addition of a tin-based condensation catalyst that has a high environmental load, and which has good storage stability and resistance to an aqueous solvent. Provided is a curable resin composition which contains (A) 100 parts by mass of an oxyalkylene polymer which has a crosslinkable silyl group in each molecule, (B) 0.1-30 parts by mass of a hydrolyzable organosilane compound which is represented by general formula (1) and has two hydrolyzable silyl-vinylene groups on the same silicon atom, (in formula (1), R1 independently represents an unsubstituted or substituted monovalent hydrocarbon group having 1 to 20 carbon atoms, R2 independently represents an unsubstituted or substituted alkyl group having 1 to 20 carbon atoms, or an unsubstituted or substituted cycloalkyl group having 3 to 20 carbon atoms, and a represents an integer of 0 to 2), (C) 0.1-300 parts by mass of an inorganic filler, and (D) 0.1-10 parts by mass of a curing catalyst.

Description

Curable resin composition and adhesive

[0001] The present invention relates to a moisture-curable resin composition primarily composed of a curable resin that can be cured by atmospheric moisture (water) at room temperature (23°C ± 15°C). More specifically, the present invention relates to a crosslinkable silyl group-containing oxyalkylene polymer composition that cures by moisture without using toxic organotin compounds, and to a curable resin composition that has resistance to aqueous solvents and suppresses bubble adhesion.

[0002] Room-temperature vulcanizable (RTV) silicone rubber compositions (room-temperature vulcanizable organopolysiloxane compositions) are known as rubber compositions that crosslink and cure in the presence of moisture. Room-temperature vulcanizable organopolysiloxane compositions are easy to handle and have excellent weather resistance and electrical properties, making them suitable for a variety of applications, including sealing materials for building materials, adhesives, and coating agents (sealants) in the electrical and electronic fields. Typical room-temperature vulcanizable organopolysiloxane compositions contain a diorganopolysiloxane (base polymer) whose molecular chain is formed by siloxane bonds and has terminal silanol groups (hydroxyl groups bonded to silicon atoms) or alkoxysilyl groups. They also contain a curing agent, an aminoalkyl-containing alkoxysilane, and a curing catalyst. Various fillers may be added as needed to impart flame retardancy, thermal conductivity, tensile strength, and other properties.

[0003] Various curing types exist for different applications. One example is the oxime-free, room-temperature-curable organopolysiloxane composition known as a sealant for construction and structures. It is widely used due to its curability, durability, and adhesiveness to various substrates. However, the resulting cured product is known to exhibit significant changes in rubber properties and poor durability when placed in a high-temperature, high-humidity environment. These sealants often use organotin compounds as curing catalysts, raising concerns about their toxicity and potential adverse effects on the environment and human health.

[0004] Furthermore, although room-temperature-curable organopolysiloxane compositions have water-repellent properties due to the hydrophobic properties of the diorganopolysiloxane itself, prolonged immersion in water can cause problems such as swelling and peeling from the substrate.

[0005] Curable resins with organic polymer main chains and crosslinkable reactive silyl groups within the molecule are also known. Crosslinkable silyl groups, such as alkoxysilyl groups, react with atmospheric moisture to hydrolyze and crosslink. Similar to the room-temperature-curable organopolysiloxane compositions described above, these resins are widely used in sealants, adhesives, coatings, and other applications (Patent Documents 1 to 3). These moisture-curable resins generally incorporate tin-based organic compounds as catalysts to accelerate curing (Patent Documents 4 and 5). While these tin-based catalysts have very high curing-accelerating activity, their toxicity has become a problem in recent years, and alternative curing catalysts have been proposed. However, tin-based catalysts are still in use due to their excellent balance of curability, the properties of the resulting cured product, and adhesiveness. Currently, these resins are being commercialized using less toxic octyltin compounds and more active alkyltin salts.

[0006] JP 2000-154368 A JP 2001-164236 A International Publication No. 2005 / 121255 JP 2012-246347 A JP 2019-014885 A

[0007] Therefore, an object of the present invention is to provide a curable resin composition and adhesive that use an oxyalkylene polymer having at least one crosslinkable silyl group per molecule, and that has excellent curability and adhesiveness, as well as good storage stability and resistance to aqueous solvents, without the addition of the tin-based condensation catalysts that have been commonly used up to now and that have a large environmental impact.

[0008] To achieve the above-mentioned object, the present inventors conducted extensive research and discovered that the above-mentioned object can be achieved by a moisture-curable resin composition and a cured product thereof, which contain an oxyalkylene polymer having at least one crosslinkable silyl group per molecule as a base polymer, a hydrolyzable organosilane compound having two hydrolyzable silyl-vinylene groups on the same silicon atom as a crosslinking agent (curing agent), and a metal organic compound other than tin as a condensation catalyst, and thus completed the present invention. That is, the present invention provides the following curable resin composition and adhesive:

[0009] [1] (A) 100 parts by mass of an oxyalkylene polymer having a crosslinkable silyl group in the molecule, (B) 0.1 to 30 parts by mass of a hydrolyzable organosilane compound having two hydrolyzable silyl-vinylene groups on the same silicon atom, represented by the following general formula (1): (In formula (1), R 1 are independently unsubstituted or substituted monovalent hydrocarbon groups having 1 to 20 carbon atoms, and R 2 are independently an unsubstituted or substituted alkyl group having 1 to 20 carbon atoms or an unsubstituted or substituted cycloalkyl group having 3 to 20 carbon atoms, and a is an integer of 0 to 2.) A curable resin composition containing: (C) 0.1 to 300 parts by mass of an inorganic filler; and (D) 0.1 to 10 parts by mass of a curing catalyst. [2] The curable resin composition according to [1], wherein component (A) is an oxyalkylene polymer having at least one crosslinkable silyl group represented by the following general formula (2) in the molecule: (In formula (2), X is a hydrocarbon group having 1 to 20 carbon atoms or an oxygen atom, and R 1 are independently unsubstituted or substituted monovalent hydrocarbon groups having 1 to 20 carbon atoms, and R 2 are independently an unsubstituted or substituted alkyl group having 1 to 20 carbon atoms or an unsubstituted or substituted cycloalkyl group having 3 to 20 carbon atoms. b is an integer of 0 to 2.) [3] The curable resin composition according to [1] or [2], wherein the curing catalyst (D) is a metal organic compound other than an organotin compound. [4] The curable resin composition according to any one of [1] to [3], wherein the zeta potential of the surface of the cured product in an aqueous KCl solution at a pH of 3.0 to 7.0 is -30 mV or more. [5] An adhesive containing the curable resin composition according to any one of [1] to [4].

[0010] The curable resin composition of the present invention exhibits excellent curability and adhesion, as well as good storage stability and resistance to aqueous solvents, without the addition of the tin-based condensation catalysts that have been commonly used in conventional room-temperature-curable organopolysiloxane compositions, which have a large environmental impact. Therefore, the composition of the present invention is useful as a variety of adhesives.

[0011] The present invention will be described in detail below.

[0012] [Component (A)] Component (A) is an oxyalkylene polymer having a crosslinkable silyl group in the molecule, preferably an oxyalkylene polymer having at least one crosslinkable silyl group represented by the following general formula (2) in the molecule, and is an important component constituting the curable resin composition of the present invention.

[0013] (In formula (2), R 1 are independently unsubstituted or substituted monovalent hydrocarbon groups having 1 to 20 carbon atoms, and R 2 are independently an unsubstituted or substituted alkyl group having 1 to 20 carbon atoms or an unsubstituted or substituted cycloalkyl group having 3 to 20 carbon atoms; X is a hydrocarbon group having 1 to 20 carbon atoms or an oxygen atom; and b is an integer of 0 to 2.

[0014] In the above formula (2), R 1 Examples of the alkyl groups include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, neopentyl, hexyl, heptyl, octyl, 2-ethylhexyl, nonyl, and decyl; cycloalkyl groups such as cyclopentyl and cyclohexyl; alkenyl groups such as vinyl, allyl, propenyl, isopropenyl, butenyl, pentenyl, hexenyl, and cyclohexenyl; aryl groups such as phenyl, tolyl, xylyl, and α- and β-naphthyl; aralkyl groups such as benzyl, 2-phenylethyl, and 3-phenylpropyl, and groups in which the hydrogen atoms of these groups are partially substituted with halogen atoms, such as 3,3,3-trifluoropropyl. Among these, a methyl group is particularly preferred. In addition, when a plurality of R 1 may be the same group or different groups.

[0015] In addition, in the above formula (2), R 2are independently an unsubstituted or substituted alkyl group having 1 to 20 carbon atoms or an unsubstituted or substituted cycloalkyl group having 3 to 20 carbon atoms, and examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group; a cyclopentyl group, and a cyclohexyl group, with a methyl group and an ethyl group being particularly preferred.

[0016] In the above formula (2), X represents an oxygen atom or a hydrocarbon group having 1 to 20 carbon atoms introduced into the polymer main skeleton. Examples of the hydrocarbon group having 1 to 20 carbon atoms include linear alkylene groups such as methylene, ethylene, propylene (trimethylene), and tetramethylene, and their isomers, such as branched alkylene groups such as isopropylene (methylethylene) and isobutylene (methylpropylene). An ethylene group is particularly preferred as X. An ethylene group is highly versatile because it can be easily produced by subjecting an α,ω-divinyl-terminated polymer to a hydrosilylation addition reaction with the corresponding hydrosilane in the presence of a metal catalyst.

[0017] In the above formula (2), b is independently for each silicon atom to be bonded an integer of 0 to 2. Preferably, b is 0 or 1, as this allows for easy availability of raw materials and provides an excellent balance between curability and the modulus of the cured product.

[0018] Examples of the oxyalkylene polymer constituting the polymer main backbone in component (A) include polyoxyethylene, polyoxypropylene, polyoxybutylene, polyoxyisobutylene, and oxypropylene-oxyethylene copolymers. Furthermore, the bonding position of the crosslinkable silyl group in component (A), preferably the crosslinkable silyl group represented by general formula (2), is not particularly limited. It may be at one or both ends of the polymer main backbone, or may be a non-terminal position, but is preferably at both ends of the polymer main backbone. That is, component (A) preferably has crosslinkable silyl groups, preferably crosslinkable silyl groups represented by general formula (2), at both molecular chain terminals of a polymer of at least one oxyalkylene selected from polyoxyethylene, polyoxypropylene, polyoxybutylene, and polyoxyisobutylene, or at both molecular chain terminals of a copolymer of at least two oxyalkylenes selected from polyoxyethylene, polyoxypropylene, polyoxybutylene, and polyoxyisobutylene.

[0019] The viscosity of the component (A) of the present invention at 25°C is preferably in the range of 25 to 500,000 mPa·s, and more preferably in the range of 500 to 100,000 mPa·s. Typically, the viscosity of the component (A) can be measured at 25°C using a rotational viscometer (e.g., a BL-type, BH-type, BS-type, cone-plate, or rheometer). Unless otherwise specified below, the viscosity of the component (A) is the value measured using a rotational viscometer at 25°C. If the viscosity of the component (A) is less than 25 mPa·s, the resulting cured product may be brittle and may not be able to achieve stretchability. Furthermore, if the viscosity of the component (A) exceeds 500,000 mPa·s, the resulting composition may have a high viscosity, resulting in poor workability. In the present invention, the degree of polymerization of the component (A) can typically be determined as the weight-average degree of polymerization (or weight-average molecular weight) in terms of polystyrene by gel permeation chromatography (GPC) analysis using THF or the like as a developing solvent. In addition, the content of the component (A) in the curable resin composition of the present invention is preferably 25 to 95 mass %, and more preferably 30 to 80 mass %.

[0020] [Component (B)] Component (B) is a hydrolyzable organosilane compound having two hydrolyzable silyl-vinylene groups on the same silicon atom, represented by the following general formula (1) (i.e., two hydrolyzable silyl groups (—Si(R 1 ) a (OR 2 ) 3-a ) each having one silicon atom in the molecule (-Si(R 1 ) 2-) is a hydrolyzable organotrisilane compound in which the silicon atom is linked to a vinylene group (—CH═CH—), and acts as a crosslinking agent (curing agent) in the composition of the present invention. (In formula (1), R 1 are independently unsubstituted or substituted monovalent hydrocarbon groups having 1 to 20 carbon atoms, and R 2 are independently an unsubstituted or substituted alkyl group having 1 to 20 carbon atoms or an unsubstituted or substituted cycloalkyl group having 3 to 20 carbon atoms; and a is an integer of 0 to 2.

[0021] Here, in the above formula (1), R 1 Examples of the alkyl groups include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, neopentyl, hexyl, heptyl, octyl, 2-ethylhexyl, nonyl, and decyl; cycloalkyl groups such as cyclopentyl and cyclohexyl; alkenyl groups such as vinyl, allyl, propenyl, isopropenyl, butenyl, pentenyl, hexenyl, and cyclohexenyl; aryl groups such as phenyl, tolyl, xylyl, and α- and β-naphthyl; aralkyl groups such as benzyl, 2-phenylethyl, and 3-phenylpropyl, and groups in which the hydrogen atoms of these groups are partially substituted with halogen atoms, such as 3,3,3-trifluoropropyl. Among these, a methyl group is particularly preferred. In addition, when a plurality of R 1 may be the same group or different groups.

[0022] In addition, in the above formula (1), R 2are independently an unsubstituted or substituted alkyl group having 1 to 20 carbon atoms or an unsubstituted or substituted cycloalkyl group having 3 to 20 carbon atoms, and examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, a cyclopentyl group, and a cyclohexyl group, with a methyl group and an ethyl group being particularly preferred.

[0023] In the above formula (1), a is independently for each silicon atom to be bonded an integer of 0 to 2. A value of 0 or 1 is preferred because raw materials are readily available and a good balance between curability and the modulus of the cured product is achieved.

[0024] A production example of component (B) is shown below. <Production of Hydrolyzable Organosilane Compound Having Two Hydrolyzable Silyl-vinylene Groups on the Same Silicon Atom> The hydrolyzable organosilane compound having two hydrolyzable silyl-vinylene groups on the same silicon atom of component (B) can be easily produced, for example, by an addition reaction via hydrosilylation between a silane having two ethynyl groups on the same silicon atom and a twice-molar amount of a hydrolyzable-group-containing hydrosilane such as an alkoxyhydrosilane. This reaction formula is represented, for example, by formula [1] below.

[0025] (In formula [1], R 1 , R 2 , a are the same as those in the general formula (1).

[0026] The addition reaction catalyst used in the addition of alkoxyhydrosilanes includes platinum group metal catalysts, such as platinum, palladium, rhodium, and ruthenium catalysts, with platinum-based catalysts being particularly preferred. Examples of platinum-based catalysts include solid platinum supported on a carrier such as platinum black, alumina, or silica, chloroplatinic acid, alcohol-modified chloroplatinic acid, a complex of chloroplatinic acid with an olefin, or a complex of platinum with a vinylsiloxane. The amount of platinum used may be a so-called catalytic amount, and can be, for example, 0.1 to 1,000 ppm, particularly 0.5 to 100 ppm, by mass, calculated as platinum group metal, relative to the alkoxyhydrosilanes.

[0027] This reaction is preferably carried out at a temperature of generally 50 to 120°C, particularly 60 to 100°C, for 0.5 to 12 hours, particularly 1 to 6 hours, and can be carried out without using a solvent. However, if necessary, a suitable solvent such as toluene or xylene can be used as long as it does not adversely affect the addition reaction.

[0028] In the addition reaction of a hydrolyzable group-containing hydrosilane, such as an alkoxyhydrosilane, to an acetylenyl group (ethynyl group), geometric isomers are produced. While the E isomer (trans isomer) is produced with high selectivity, the Z isomer (cis isomer) can also be used without separating it because it does not adversely affect the properties of the component (B) in the curable resin composition of the present invention.

[0029] Specific examples of hydrolyzable organosilane compounds having two hydrolyzable silyl-vinylene groups, such as alkoxysilyl-vinylene groups, on the same silicon atom of general formula (1) include those represented by the following structural formulas, and these can be used alone or in combination of two or more as component (B).

[0030] The hydrolyzable organosilane compound of component (B) is used in an amount of 0.1 to 30 parts by mass, preferably 1 to 20 parts by mass, per 100 parts by mass of component (A). If the amount is less than 0.1 part by mass, sufficient crosslinking may not be obtained, and the composition may not have the desired curability. If the amount is more than 30 parts by mass, the mechanical properties of the resulting rubber may also decrease, which may be economically disadvantageous. The hydrolyzable organosilane compound of component (B) may be used alone or in combination of two or more types.

[0031] [Component (C)] The inorganic filler of component (C) is a component added for the purpose of improving the strength, thixotropy, etc. of the composition. Specific examples include silica-based fillers such as dry silica (e.g., calcined silica, crushed silica, fused silica, and fumed silica), wet silica (e.g., precipitated silica, colloidal silica, and sol-gel silica), and crystalline silica (fine quartz powder), which may or may not be surface-hydrophobized, aluminum hydroxide, alumina, boehmite, magnesium hydroxide, magnesium oxide, calcium hydroxide, calcium carbonate, zinc carbonate, basic zinc carbonate, zinc oxide, barium sulfate, titanium oxide, carbon black, glass beads, and glass balloons. These inorganic fillers may be used alone or in combination of two or more. These inorganic fillers may be untreated or may be surface-hydrophobized with a known treatment agent.

[0032] If the inorganic filler of component (C) has a relatively small particle size, such as on the order of nanometers, it is preferable that the BET specific surface area be 50 to 300 m. 2 / g is preferred, and 50 to 200m 2 / g is more preferable. Furthermore, if the inorganic filler of component (C) is a relatively large filler, such as one with a particle size on the order of micrometers, the average particle size is preferably 1 to 200 μm, and more preferably 1 to 100 μm. The average particle size of component (C) is the volume average value (median diameter) measured using a laser scattering particle size distribution analyzer.

[0033] The component (C) is used in an amount of 0.1 to 300 parts by mass, and preferably 1 to 300 parts by mass, per 100 parts by mass of the component (A). If the amount is less than 0.1 part by mass, the composition will not have sufficient strength, while if the amount is more than 300 parts by mass, workability will deteriorate and the elasticity of the resulting rubber physical properties will decrease, which may be economically disadvantageous.

[0034] [Component (D)] The component (D) is an important compound that functions as a condensation catalyst in the curable resin composition of the present invention, and may be used alone or as a mixture of two or more. The component (D) is preferably an organic compound other than an organotin compound, and more preferably an organic metal compound other than an organotin compound. Specific examples of the catalyst include titanate esters or titanium chelate compounds such as tetraisopropoxytitanium, tetra-n-butoxytitanium, tetrakis(2-ethylhexoxy)titanium, diisopropoxybis(acetylacetonato)titanium, diisopropoxybis(ethylacetoacetate)titanium, and titanium isopropoxyoctylene glycol; aluminum alcoholates or aluminum chelate compounds such as aluminum isopropylate, aluminum sec-butylate, aluminum ethylate, ethylacetoacetate aluminum diisopropylate, aluminum tris(ethylacetoacetate), and alkylacetoacetate aluminum diisopropylate; silanes or siloxanes containing a guanidyl group such as tetramethylguanidylpropyltrimethoxysilane, tetramethylguanidylpropylmethyldimethoxysilane, and tetramethylguanidylpropyltris(trimethylsiloxy)silane; and conventionally known catalysts such as lead octoate and other acidic or basic catalysts. In particular, titanium chelate compounds are preferred, with diisopropoxybis(acetylacetonato)titanium and diisopropoxybis(ethylacetoacetate)titanium being particularly preferred.

[0035] The amount of component (D) blended is 0.1 to 10 parts by mass, preferably 0.5 to 8 parts by mass, and more preferably 0.5 to 6 parts by mass, per 100 parts by mass of component (A). If the amount of component (D) blended is less than 0.1 part by mass, it may not function as the intended end-capping catalyst. If the amount of component (D) blended exceeds 10 parts by mass, it is undesirable from the standpoint of cost.

[0036] [Other Components] In order to further improve the adhesion of the cured product of the composition of the present invention to various adherends, a silane coupling agent (a hydrolyzable silane compound such as an alkoxysilane having a monovalent hydrocarbon group with a functional group (excluding a guanidyl group) containing a heteroatom selected from nitrogen, sulfur, and oxygen in one molecule, or a so-called carbon functional silane compound) may be blended into the composition as an adhesion promoter as an optional component that can be blended as needed. Examples of the silane coupling agent include silane compounds having an alkoxysilyl group or an alkenoxysilyl group as the hydrolyzable group, such as vinyltris(β-methoxyethoxy)silane, γ-methacryloxypropyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, 3-(N-aminopropyl)-2-methylpropyltriethoxysilane, 2-(N-aminopropyl)-2-methylpropyltriethoxysilane, 1 ... Examples include N,N'-bis[3-(trimethoxysilyl)propyl]ethylenediamine, N,N-bis[3-(trimethoxysilyl)propyl]amine, γ-mercaptopropyltrimethoxysilane, γ-glycidoxypropyltriisopropenoxysilane, γ-glycidoxypropylmethyldiisopropenoxysilane, reaction products of (meth)acrylic silane and aminosilane, reaction products of epoxy silane and aminosilane, reaction products of aminosilane and halogenated alkyl group-containing silane, etc. In particular, it is preferable to use a silane coupling agent having at least one amino group in one molecule.

[0037] When a silane coupling agent is added, the amount added is usually 0.1 to 20 parts by mass, preferably 0.1 to 10 parts by mass, and particularly preferably 0.1 to 5 parts by mass per 100 parts by mass of component (A). Less than 0.1 part by mass may result in insufficient adhesion, while more than 20 parts by mass may result in insufficient mechanical properties or may be uneconomical in terms of cost. If necessary, known additives may be added within a range that does not impair the objectives of the present invention. For example, polyethers as wetters or thixotropy improvers, non-reactive dimethyl silicone oils and isoparaffins as plasticizers, and trimethylsiloxy units [(CH3)3SiO] as crosslink density improvers may be added. 1 / 2 units] and SiO2 units.

[0038] Furthermore, if necessary, colorants such as pigments, dyes and fluorescent brighteners, antifungal agents, antibacterial agents, surface modifiers such as non-reactive phenylsilicone oils as bleed oils, fluorosilicone oils and organic liquids, and solvents such as toluene, xylene, volatile solvent oils, cyclohexane, methylcyclohexane and low-boiling point isoparaffins may also be added.

[0039] <Method for producing the composition> The curable resin composition of the present invention can be obtained by mixing the above components (A) to (D) and, if necessary, other components. The mixing method may be a conventional method, and the components may be mixed under reduced pressure.

[0040] The curable resin composition of the present invention is preferably stored in an atmosphere protected from moisture. When the composition is left in an air atmosphere at room temperature (23°C ± 15°C) for use, it is cured by the moisture (humidity) in the air, usually within 5 minutes to 1 week.

[0041] The cured product of the curable resin composition of the present invention obtained by the above method preferably has a zeta potential of -30 mV or more on the surface in a KCl aqueous solution at a pH of 3.0 to 7.0, i.e., a zeta potential of -30 mV or more on the surface in a KCl aqueous solution over the pH range of 3.0 to 7.0. More specifically, the zeta potential is a value measured by curing the curable resin composition of the present invention by leaving it to cure for 7 days under curing conditions of 23°C / 50% RH to obtain a cured product of any shape as a test piece, and then measuring the zeta potential of the test piece surface in a 1.0 mM KCl aqueous solution at a pH of 3.0 to 7.0. Commercially available devices can be used to measure the zeta potential of the solid surface that is the cured product of the curable resin composition of the present invention, such as a SurPASS ZETA meter. TM 3 (manufactured by Anton Paar) can be mentioned.

[0042] EXAMPLES Hereinafter, examples and comparative examples will be shown to specifically explain the present invention, but the present invention is not limited to the following examples.

[0043] <Method for Preparing Component (A)> 1,000 g of polyoxypropylene ether (molecular weight 12,400, allyl group amount 0.157 mol / kg) with a viscosity of 55,000 mPa·s and allyl groups attached to both molecular chain terminals and 0.75 g of chloroplatinic acid (HPtCl·6H O) were placed in a round-bottom flask and heated to 90°C with stirring. Under this condition, 15 g of dimethoxymethylsilane was added dropwise to the round-bottom flask and allowed to react. Heat generation was confirmed during the dropwise addition, and the temperature was confirmed to rise to approximately 100°C. After the entire amount of dimethoxymethylsilane was added dropwise, the mixture in the round-bottom flask was again stirred at 90°C for 5 hours. After completion of the reaction, the mixture was treated at 90°C / 10 mmHg for 1 hour to prepare Polymer A, a pale yellow liquid (11,000 mPa·s, Mw 19,000). Polymer A has a polymer main skeleton composed of polyoxypropylene and has crosslinkable silyl groups (in formula (2), X is a methylene group and R 1 and R 2 are methyl groups and b is 1).

[0044] Example 1: 100 parts by mass of polymer A as component (A) prepared above, and a BET specific surface area of ​​130 m 2 8 parts by mass of fumed silica having a particle size of 1 / g and 100 parts by mass of crystalline silica having an average particle size of 15 μm were mixed uniformly under reduced pressure for 30 minutes. Then, bis(dimethoxymethylsilyl-vinylene)dimethylsilane (i.e., the compound represented by the formula (1) above, R 1 =R 2 = methyl group, a = 1.), 7 parts by mass of N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, and 4 parts by mass of diisopropoxybis(ethylacetoacetate)titanium were added and mixed under reduced pressure for 15 minutes to obtain Composition 1.

[0045] Example 2: 100 parts by mass of polymer A as component (A) prepared above, and a BET specific surface area of ​​130 m 2 8 parts by mass of fumed silica having a particle size of 1 / g and 100 parts by mass of crystalline silica having an average particle size of 15 μm were mixed uniformly under reduced pressure for 30 minutes. Then, bis(trimethoxysilyl-vinylene)dimethylsilane (i.e., the compound represented by the formula (1) above, R 1 =R 2 = methyl group, a = 0.) 7 parts by mass of N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, 0.5 parts by mass of N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, and 4 parts by mass of diisopropoxybis(ethylacetoacetate)titanium were added and mixed under reduced pressure for 15 minutes to obtain Composition 2.

[0046] Example 3: 100 parts by mass of polymer A as component (A) prepared above, and a BET specific surface area of ​​130 m 2 8 parts by mass of fumed silica having a particle size of 1 / g, 30 parts by mass of ground calcium carbonate having an average particle size of 2.3 μm, and 120 parts by mass of paraffin-treated ground calcium carbonate having an average particle size of 2.0 μm were mixed uniformly under reduced pressure for 30 minutes. Then, bis(trimethoxysilyl-vinylene)dimethylsilane (i.e., the compound represented by the formula (1) above, R 1 =R 2= methyl group, a = 0.) 7 parts by mass of N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, 0.5 parts by mass of N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, and 4 parts by mass of diisopropoxybis(ethylacetoacetate)titanium were added and mixed under reduced pressure for 15 minutes to obtain Composition 3.

[0047] Example 4: 100 parts by mass of polymer A as component (A) prepared above, and a BET specific surface area of ​​130 m 2 8 parts by mass of fumed silica having a particle size of 1 / g and 150 parts by mass of barium sulfate having an average particle size of 10 μm were mixed uniformly under reduced pressure for 30 minutes. Then, bis(trimethoxysilyl-vinylene)dimethylsilane (i.e., the compound represented by the formula (1) above, R 1 =R 2 = methyl group, a = 0.) 7 parts by mass of N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, 0.5 parts by mass of N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, and 4 parts by mass of diisopropoxybis(ethylacetoacetate)titanium were added and mixed under reduced pressure for 15 minutes to obtain Composition 4.

[0048] Comparative Example 1: 100 parts by mass of polymer A as component (A) prepared above, and a BET specific surface area of ​​130 m 2 Eight parts by mass of fumed silica having a particle size of 1 / g and 100 parts by mass of crystalline silica having an average particle size of 15 μm were mixed uniformly under reduced pressure for 30 minutes. Next, to this mixture were added 7 parts by mass of methyltrimethoxysilane, 0.5 parts by mass of N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, and 4 parts by mass of diisopropoxybis(ethylacetoacetate)titanium, and the mixture was mixed under reduced pressure for 15 minutes to obtain Composition 5.

[0049] Comparative Example 2: 100 parts by mass of polydimethylsiloxane whose molecular chain ends are blocked with trimethoxysilyl groups and whose viscosity at 25°C is 20,000 mPa·s, BET specific surface area 130 m 2 8 parts by mass of fumed silica having a particle size of 1 / g and 100 parts by mass of crystalline silica having an average particle size of 15 μm were mixed uniformly under reduced pressure for 30 minutes. Then, bis(dimethoxymethylsilyl-vinylene)dimethylsilane (i.e., the compound represented by the formula (1) above, R 1 =R 2= methyl group, a = 1.), 7 parts by mass of N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, and 4 parts by mass of diisopropoxybis(ethylacetoacetate)titanium were added and mixed under reduced pressure for 15 minutes to obtain Composition 6.

[0050] The prepared compositions 1 to 6 were used to measure the following properties.

[0051] Tack-Free Time The tack-free time (minutes) of each of the prepared compositions 1 to 6 was evaluated by touching with a finger in an environment of 23°C / 50% RH according to the method described in JIS K 6249. The results are shown in Table 1.

[0052] Each of the prepared compositions 1 to 6 was left to cure for 7 days in an environment of 23°C / 50% RH to a thickness of 3 mm, and a measurement sample having a thickness of 3 mm was prepared, and the hardness, elongation, and tensile strength were measured in accordance with JIS K 6249. The results obtained are shown in Table 1.

[0053] Adhesion Each of the prepared compositions 1 to 6 was applied to a 2 mm thickness on an AL1050P substrate (0.3 mm thick) whose surface had been washed with toluene. The coating was then cured for 7 days at 23°C / 50% RH to prepare a measurement sample in which a cured layer (2 mm thick) was laminated on the substrate. After 7 days, the rubber (cured composition) was peeled from the AL1050P substrate (measurement sample in which a cured layer was laminated on a substrate), and adhesion was confirmed and evaluated according to the following criteria. The results are shown in Table 1. ○: When a 1 cm cut was made at the interface between the AL1050P substrate and the rubber and the sample was pulled by hand in the shear direction, the rubber did not peel from the adherend (cohesive failure). ×: When a 1 cm cut was made at the interface between the AL1050P substrate and the rubber and the sample was pulled by hand in the shear direction, the rubber peeled from the adherend (interface peeling).

[0054] Storage Stability Each of the prepared Compositions 1 to 6 was placed in a sealable polyethylene container and left to stand for 7 days in an environment at 70°C. Thereafter, the container was left to stand for 7 days in an environment of 23°C / 50% RH to harden to a thickness of 3 mm, and a measurement sample with a thickness of 3 mm was prepared, and the hardness, elongation, and tensile strength were measured in accordance with JIS K 6249. The results are shown in Table 2. The values ​​measured before leaving the container in an environment of 70°C for 7 days were used as the initial values.

[0055]

[0056] Compositions 1 to 4 and 6 all exhibited good curability and adhesiveness. Composition 5 exhibited poor curability and peeling was observed in the adhesive properties.

[0057]

[0058] All of Compositions 1 to 4 showed the same properties as when they were initially stored at 70° C. for 7 days, whereas Composition 6 showed a slight decrease in physical properties.

[0059] - Evaluation of Resistance to Aqueous Solvents (1) Changes in Appearance and Weight Each of the prepared compositions 1 to 6 was left to cure for 7 days in a 23°C / 50% RH environment to a size of 15 mm x 15 mm x 3 mm (thickness), producing a test specimen. The weight of the test specimen was measured and used as the initial value. An aqueous solvent consisting of 10 mL of ion-exchanged water and 5 mL of glycerin was placed in a 50 mL sealable glass bottle, and each test specimen was completely immersed in the aqueous solvent and the bottle was sealed. The glass bottle was then placed in a 60°C oven and left for 1 week. After 1 week, the test specimen was removed from the aqueous solvent, washed twice each with ion-exchanged water and ethanol, and then left for 1 hour in a 23°C / 50% RH environment. The appearance was confirmed and the weight was measured. The weight change relative to the initial value was calculated and recorded. The results are shown in Table 3.

[0060] (2) Air Bubble Adhesion Each of the prepared compositions 1 to 6 was left to harden for 7 days in a 23°C / 50% RH environment to a size of 15 mm x 15 mm x 3 mm (thickness), producing a test specimen. A water-based solvent consisting of 10 mL of ion-exchanged water and 5 mL of glycerin was placed in a 50 mL sealable glass bottle, and each test specimen was completely immersed in the water-based solvent and the bottle was sealed. The glass bottle was then shaken up and down 20 times and allowed to stand, and the test specimen was visually inspected for air bubble adhesion. Evaluation was based on the following criteria: ○: No air bubbles adhered to the interface of the test specimen. ×: Air bubbles adhered to the interface of the test specimen. The results are shown in Table 3.

[0061] (3) Zeta Potential Measurement Each of the prepared compositions 1 to 6 was left to harden for 7 days in an environment of 23°C / 50% RH to prepare a test specimen measuring 100 mm x 100 mm x 1 mm (thickness). TM The zeta potentials of Compositions 1 to 6 were measured at pH 3.0, pH 5.0, and pH 7.0 (1.0 mM KCl aqueous solution) using the method described in 3. The results are shown in Table 4.

[0062]

[0063] Compositions 1 to 4 showed no change in appearance after immersion in an aqueous solvent, and only a small change in weight. Furthermore, no air bubbles formed on the test specimens, demonstrating good resistance. On the other hand, composition 6 caused the test specimens to swell significantly, resulting in a large change in weight and the formation of air bubbles.

[0064]

[0065] For compositions 1 to 4, the zeta potential of the cured surface in KCl aqueous solution was -30 mV or higher in the pH range of 3.0 to 7.0. On the other hand, for composition 6, the zeta potential of the cured surface in KCl aqueous solution at pH 7.0 decreased to less than -30 mV as the pH increased. This result is related to the data in Table 3, and it can be seen that the lower the zeta potential, the worse the resistance to aqueous solvents.

[0066] From the above, it has been found that the curable resin composition of the present invention has excellent curability and adhesiveness without the addition of a tin-based condensation catalyst, as well as good storage stability and resistance to aqueous solvents. Therefore, the composition of the present invention is useful as various adhesives, and is particularly useful as adhesives that are applied to locations that come into contact with aqueous solvents or in aqueous solvents.

Claims

1. (A) 100 parts by mass of an oxyalkylene polymer having a crosslinkable silyl group in the molecule; (B) 0.1 to 30 parts by mass of a hydrolyzable organosilane compound having two hydrolyzable silyl-vinylene groups on the same silicon atom, represented by the following general formula (1): (In formula (1), R 1 are independently unsubstituted or substituted monovalent hydrocarbon groups having 1 to 20 carbon atoms, and R 2 are independently an unsubstituted or substituted alkyl group having 1 to 20 carbon atoms or an unsubstituted or substituted cycloalkyl group having 3 to 20 carbon atoms, and a is an integer of 0 to 2. A curable resin composition comprising: (C) 0.1 to 300 parts by mass of an inorganic filler; and (D) 0.1 to 10 parts by mass of a curing catalyst.

2. The curable resin composition according to claim 1, wherein component (A) is an oxyalkylene polymer having at least one crosslinkable silyl group represented by the following general formula (2) in the molecule: (In formula (2), X is a hydrocarbon group having 1 to 20 carbon atoms or an oxygen atom, and R 1 are independently unsubstituted or substituted monovalent hydrocarbon groups having 1 to 20 carbon atoms, and R 2 are independently an unsubstituted or substituted alkyl group having 1 to 20 carbon atoms or an unsubstituted or substituted cycloalkyl group having 3 to 20 carbon atoms; and b is an integer of 0 to 2.

3. The curable resin composition according to claim 1, wherein the curing catalyst (D) is a metal organic compound other than an organotin compound.

4. The curable resin composition according to claim 1, wherein the zeta potential of the surface of the cured product in an aqueous KCl solution having a pH of 3.0 to 7.0 is -30 mV or more.

5. An adhesive containing the curable resin composition according to any one of claims 1 to 4.

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