Bonding member disassembly method and easily disintegrable liquid silicone-based adhesive

Abstract

A bonded member, which is obtained by bonding a plurality of members, including a member in which at least a portion of a bonding interface is a metal, with a cured product obtained by curing a curable liquid silicone adhesive, exhibits sealing properties even after being exposed at room temperature and further at a high temperature of about 150 DEG C; at the same time, the metal portion of the bonding interface is heated by electromagnetic induction, so that the bonding member in the bonding member can be easily disassembled in a short time and with less energy consumption, and the disassembled member can be reused. The curable liquid silicone adhesive contains 25-80% by mass of a hydroxide compound having a decomposition temperature of 180-600 DEG C, and the content of a material that generates heat by electromagnetic induction is 3% by mass or less.

Description

Technical Field

[0001] The present invention relates to a method for disassembling a joining member using a curable liquid silicone-based adhesive, which enables operations such as recycling, repair, and reuse of automotive components such as automotive electrical components and electrical and electronic products to be easily performed in a short time, and an easily disassemblable liquid silicone-based adhesive used in this method. Background Art

[0002] In recent years, from the aspects of being environmentally friendly and reducing costs, reusability has been required in various fields. Reuse is also carried out in the automotive field, electrical and electronic field, etc., so disassembly between components in a joining member is required. On the other hand, the joining member plays an important role in preventing the intrusion of external dust and moisture and protecting internal components, so reliable sealing performance is also required. Since the sealing by adhesion is the most excellent in terms of its sealing performance, it is necessary to maintain adhesiveness under various conditions (heat resistance, moisture resistance, etc.). Therefore, usually, the cured product adheres firmly to the base material, and it is not easy to remove the joining member.

[0003] As a method for reusing a joining member using a curable resin composition, for example, in Japanese Patent Laid-Open No. 2003-026784 (Patent Document 1), it is proposed that by heating a joining member using a polyol-based curable composition to 150 to 200°C, it is softened or liquefied, and the components joined by the cured product are disassembled. In addition, in Japanese Patent Laid-Open No. 2002-327163 (Patent Document 2), it is proposed that by bringing a halogen-based organic solvent into contact with the bonding part of a bonding structure using a moisture-curable adhesive mainly composed of a urethane prepolymer, the adhesive force of the bonding part is reduced, and then the constituent members of the bonding structure are peeled off and disassembled from the bonding part. Furthermore, in Japanese Patent Laid-Open No. 2008-120903 (Patent Document 3), a re-peelable desensitizing adhesive tape is proposed, in which an adhesive composed of a vinyl monomer mixture mainly composed of (meth)acrylic acid alkyl ester is used, and a high normal adhesive force is maintained during joining, while when the joined part is separated and disassembled, the adhesive force is reduced by heating, and it can be easily separated and disassembled. Moreover, in Japanese Patent No. 6221630 (Patent Document 4), it is proposed that by containing a pressure-sensitive adhesiveness-imparting resin in an alkylene oxide polymer, it can be reprocessed, and it can be re-bonded after reprocessing, and the sealing performance can be maintained.

[0004] On the other hand, silicone-based adhesives and sealants are excellent in properties such as heat resistance and weather resistance compared with the above-mentioned organic adhesives, and thus are widely used in the automotive field, electrical and electronic field, construction field, etc. On the other hand, even when heated, silicone-based adhesives and sealants are difficult to decompose, so there is a problem that they are difficult to repair or reuse.

[0005] As a silicone-based adhesive that is easy to disassemble between components and can exhibit sealing performance, a mask-type silicone-based adhesive has been proposed. The mask-type silicone-based adhesive without an adhesion-imparting agent is a silicone-based adhesive to which a peelability-imparting agent is added to impart releasability to glass and metal. However, in high-temperature durability exceeding 200°C, the peelability-imparting agent itself thermally decomposes and loses its effectiveness, and the component and the silicone-based adhesive are bonded by heat, making disassembly difficult and recovery and repair difficult.

[0006] Therefore, in applications where components are bonded and joined with a silicone-based adhesive, a reusable joined component and a method for disassembling the same are also required.

[0007] Prior Art Documents

[0008] Patent Documents

[0009] Patent Document 1: Japanese Patent Application Laid-Open No. 2003-026784

[0010] Patent Document 2: Japanese Patent Application Laid-Open No. 2002-327163

[0011] Patent Document 3: Japanese Patent Application Laid-Open No. 2008-120903

[0012] Patent Document 4: Japanese Patent No. 6221630

[0013] Patent Document 5: Japanese Patent Application Laid-Open No. 2022-183437

[0014] Patent Document 6: Japanese Patent Application No. 2021-160447 Summary of the Invention

[0015] Problems to be Solved by the Invention

[0016] The present invention has been completed in view of the above actual situation, and an object thereof is to provide an adhesive for joined components that is a silicone-based adhesive, exhibits sealing performance even at room temperature (23°C ± 15°C, the same hereinafter) and even after exposure to a high temperature of about 150°C, and at the same time, a method for disassembling a joined component that can be easily reused with a short time and less energy consumption, and a liquid silicone-based adhesive with easy disassembly used in the method for disassembling the joined component.

[0017] Means for Solving the Problems

[0018] In order to achieve the above object, the inventor proposed the following method in Japanese Patent Application Laid-Open No. 2022-183437 (Japanese Patent Application No. 2021-090750) (Patent Document 5): Aluminum hydroxide that decomposes around 160°C is blended in a curable liquid silicone-based adhesive in a specific ratio, so that the bonded members joined thereby exhibit sealing performance even after being exposed at room temperature or even at a high temperature of about 150°C. By being exposed to a high temperature of 160°C or higher, the sealing performance is reduced, and it becomes easy to separate the members. However, this method uses a heating furnace and requires long-term heating for several hours, so the energy consumption is large.

[0019] In addition, Japanese Patent Application No. 2021-160447 (Patent Document 6) proposed the following method: By irradiating a microwave to a joined member that joins a plurality of members with a curable liquid silicone-based adhesive containing particles that generate heat by microwave and a hydroxide compound having a decomposition temperature of 180 to 600°C, it becomes easy to disassemble between the plurality of members. However, even this method requires several minutes, and it is desired to disassemble in a shorter time.

[0020] Therefore, the inventor has intensively studied a joined member and a disassembly method thereof that consume less energy and can be reused in a short time, and as a result, it has been found that in order to improve the efficiency and energy saving of recycling, repair, and reuse operations of automotive parts, electrical and electronic products, etc., a joined member joined between a plurality of members having at least a part of a joining interface made of metal by a cured product obtained by curing a curable liquid silicone-based adhesive exhibits sealing performance even after being exposed at room temperature or even at a high temperature of about 150°C. At the same time, by heating the metal part of the joining interface by electromagnetic induction, the joined member can be easily disassembled within the joined member in a short time with less energy consumption, and the disassembled members can be reused. The curable liquid silicone-based adhesive contains 25 to 80% by mass of a hydroxide compound (particularly a metal hydroxide or a hydroxide of a metal oxide) having a decomposition temperature of 180 to 600°C, and the content of the material that generates heat by electromagnetic induction is 3% by mass or less, and the present invention has been completed.

[0021] Therefore, the present invention provides the following disassembly method of a joined member and an easily disassemblable liquid silicone-based adhesive.

[0022] [1]A method for disassembling a joined member, comprising the following steps: for a joined member formed by joining a plurality of members, at least a part of the joined interface of which is a member made of metal, and which is formed by curing a curable liquid silicone-based adhesive, heating the metal part of the joined interface by electromagnetic induction, so as to separate the member containing the metal in these members to disassemble the joined member, wherein the curable liquid silicone-based adhesive contains 25 to 80% by mass of a hydroxide compound having a decomposition temperature of 180 to 600 °C, and the content of the material that generates heat by electromagnetic induction is 3% by mass or less.

[0023] [2]The method for disassembling a joined member according to [1], wherein the curable liquid silicone-based adhesive is a condensation-curing type liquid silicone-based adhesive, an addition reaction-curing type liquid silicone-based adhesive, or an ultraviolet-curing type liquid silicone-based adhesive.

[0024] [3]The method for disassembling a joined member according to [1] or [2], wherein the hydroxide compound having a decomposition temperature of 180 to 600 °C is at least one selected from aluminum hydroxide, magnesium hydroxide, and aluminum hydroxide (boehmite).

[0025] [4]The method for disassembling a joined member according to any one of [1] to [3], wherein the frequency of electromagnetic induction heating is 100 kHz or more and 500 kHz or less.

[0026] [5]The method for disassembling a joined member according to any one of [1] to [4], wherein the joined member is an automotive part or an electrical and electronic part.

[0027] [6]A condensation-curing type liquid silicone-based adhesive with easy disassembly property, which contains the following components (A) to (E) for the method for disassembling a joined member according to any one of [1] to [5], and the content of the material that generates heat by electromagnetic induction is 3% by mass or less,

[0028] (A) A hydroxide compound having a decomposition temperature of 180 to 600 °C: its amount is 25 to 80% by mass of the whole adhesive,

[0029] (B) A linear diorganopolysiloxane having hydroxyl groups and / or hydrolyzable silyl groups bonded to silicon atoms at both ends of the molecular chain: 100 parts by mass,

[0030] (C) A hydrolyzable organosilane compound having 3 or more hydrolyzable groups bonded to silicon atoms in the molecule and / or its partial hydrolysis condensate: 0.1 to 40 parts by mass,

[0031] (D) A curing catalyst: 0.001 to 20 parts by mass, and

[0032] (E) Silane coupling agent: 0.05 to 20 parts by mass.

[0033] [7] An easily decomposable addition reaction-curable liquid organosilicon adhesive, which contains the following components (A) and (F) to (H) for the decomposition method of the joining member according to any one of [1] to [5], and the content of the material using electromagnetic induction heating is 3% by mass or less.

[0034] (A) Hydroxide compound with a decomposition temperature of 180 to 600 °C: Its amount is 25 to 80% by mass of the entire adhesive.

[0035] (F) Alkenyl-containing organopolysiloxane having an alkenyl bonded to a silicon atom at the molecular chain end: 100 parts by mass.

[0036] (G) Organohydrogenpolysiloxane having at least two hydrogen atoms bonded to silicon atoms in the molecule: Its amount is such that, relative to 1 mole of the alkenyl bonded to a silicon atom in component (F), the hydrogen atoms bonded to silicon atoms are 0.01 to 3 moles.

[0037] (H) Platinum group metal catalyst: 0.01 to 1000 ppm in terms of the mass conversion of platinum group metal atoms, relative to the total amount of components (F) and (G), and

[0038] (I) Adhesion-imparting agent: 0.05 to 20 parts by mass.

[0039] [8] An easily decomposable ultraviolet-curable liquid organosilicon adhesive, which contains the following components (A) and (J), (K) for the decomposition method of the joining member according to any one of [1] to [5], and the content of the material using electromagnetic induction heating is 3% by mass or less.

[0040] (A) Hydroxide compound with a decomposition temperature of 180 to 600 °C: Its amount is 25 to 80% by mass of the entire adhesive.

[0041] (J) Ultraviolet-reactive organopolysiloxane: 100 parts by mass, and

[0042] (K) Photoinitiator: 0.01 to 10 parts by mass.

[0043] Effects of the invention

[0044] According to the method for disassembling a joining member of the present invention, it exhibits adhesiveness and / or sealing property from room temperature to a high temperature of about 150°C. At the same time, the metal part of the joining interface is heated by electromagnetic induction heating, thereby indirectly heating the cured product of the curable liquid silicone-based adhesive as the bonding member, reducing the adhesiveness and / or sealing property. As a result, the members containing metal at the joining interface can be peeled off with a short time and less energy, so that the joining member can be easily disassembled and reused. The curable liquid silicone-based adhesive used in this disassembling method can be used as an adhesive or sealing material for joining parts that require heat resistance and need to be reused.

[0045] Furthermore, in the present invention, the "heat-resistant temperature" of the member to be disassembled means the upper limit of the temperature at which the member does not undergo thermal decomposition or softening when the member is left standing at a specific temperature for one minute. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 It is an image for observing the surface state of the ADC12 base material before electromagnetic induction heating by using a digital microscope in Example 1 of the present invention.

[0047] Figure 2 It is an image for observing the surface state of the ADC12 base material after electromagnetic induction heating by using a digital microscope in Example 1 of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0048] The present invention will be described in detail below.

[0049] The method for disassembling a joining member of the present invention includes the following steps: For a joining member in which a plurality of members, at least a part of the joining interface of which is metal, are joined by a cured product obtained by curing a curable liquid silicone-based adhesive, the metal part of the joining interface is heated by electromagnetic induction, so that the members containing metal in these members are separated to disassemble the joining member. The curable liquid silicone-based adhesive contains 25 to 80% by mass of a hydroxide compound (particularly, a metal hydroxide or a hydroxide of a metal oxide) having a decomposition temperature of 180 to 600°C, and the content of the material that generates heat by electromagnetic induction is 3% by mass or less.

[0050] [Curable Liquid Silicone-Based Adhesive]

[0051] The curable liquid silicone-based adhesive used in the present invention cures into an adhesive member that joins multiple members including at least a part of the joining interface being metal. It is an adhesive containing a hydroxide compound (A) with a decomposition temperature of 180 to 600 °C, the content of the material that generates heat by electromagnetic induction is 3% by mass or less, and a polymer with a main chain composed of siloxane bonds is used as the base polymer. The curing type is preferably condensation curing type, addition reaction curing type, or ultraviolet curing type.

[0052] [Hydroxide compound with a decomposition temperature of 180 to 600 °C]

[0053] The hydroxide compound with a decomposition temperature of 180 to 600 °C is usually preferably a metal hydroxide or a hydroxide of a metal oxide. Aluminum hydroxide with a decomposition temperature near 180 °C, magnesium hydroxide with a decomposition temperature near 300 °C, and aluminum hydroxide (boehmite) with a decomposition temperature near 500 °C can be cited. Furthermore, the so-called "decomposition temperature" is the temperature at which the hydroxide compound decomposes to start generating water.

[0054] They are heated and start to decompose, generating water through decomposition, so they have an anti-inflammatory effect and have been used in flame-retardant materials in the past. In the present invention, by using the water generated through this decomposition, the adhesive force is reduced due to the bubbles generated in the cured product of the curable liquid silicone-based adhesive, so that the disassembly of the joined members can be achieved in a short time and becomes easy.

[0055] As the hydroxide compound with a decomposition temperature of 180 to 600 °C, a particulate hydroxide compound with an average particle diameter of 50 μm or less, preferably 0.5 to 20 μm, is used. If the average particle diameter is larger than 50 μm, the decomposability decreases. It should be noted that the average particle diameter can be obtained as the cumulative weight average D50 (or median diameter) using a particle size distribution measuring device such as the laser diffraction method.

[0056] The surface of this hydroxide compound may be untreated or surface-treated (hydrophobized). In the case of surface treatment, a treatment agent is usually used, and examples include silane coupling agents and fatty acids. The surface treatment can be carried out by a known method. The treatment amount is not particularly limited, preferably 3% by mass or less (usually 0.1 to 3% by mass), and particularly preferably 0.2 to 2% by mass.

[0057] Furthermore, one kind of hydroxide compound can be used alone, or two or more kinds of hydroxide compounds with different average particle diameters and surface treatment methods can be used together.

[0058] The content of the hydroxide compound is 25 to 80% by mass, preferably 30 to 70% by mass, more preferably 35 to 65% by mass, of the entire curable liquid silicone-based adhesive. If it is less than 25% by mass, the decomposition (foaming) of the hydroxide compound is insufficient and the disassembly property is reduced. If it is in an amount exceeding 80% by mass, the viscosity of the composition increases and the discharge property during mixing and application deteriorates.

[0059] [Materials that generate heat by electromagnetic induction]

[0060] Examples of materials that generate heat by electromagnetic induction include metal materials, carbon materials such as carbon fibers and carbon black. Examples of metal materials used in curable liquid silicone-based adhesives include aluminum powder, iron powder, copper powder, and alloy powders thereof.

[0061] The curable liquid silicone-based adhesive used in the present invention contains extremely little material that generates heat by electromagnetic induction. Even if a component contained in an additive such as a coloring agent as an optional component contains a material that generates heat by electromagnetic induction, its blending amount in the curable liquid silicone-based adhesive is 3% by mass or less (0 to 3% by mass), and particularly 1% by mass or less (0 to 1% by mass). If it exceeds 3% by mass, the disassembly property is reduced.

[0062] The electromagnetic induction heating used in the heating of the present invention can heat a conductive metal material or a carbon material (such as carbon fiber, graphite, carbon black, etc.). On the other hand, in the case of the present invention, by heating the joint interface portion of the metal used in the joint member by electromagnetic induction, peeling can occur efficiently in a short time. However, if a material that generates heat by electromagnetic induction is added to the adhesive itself, the energy of electromagnetic induction is also used for heating the adhesive member (the cured product of the adhesive), so the disassembly property is reduced. In addition, when an organic resin is used in the member, by heating the adhesive member, the organic resin in contact with the adhesive member is heated to exceed its heat resistance, causing melting and decomposition of the organic resin, which is not suitable for reusing the member. Therefore, it is preferable to add extremely little material that generates heat by electromagnetic induction (set to 3% by mass or less) to the curable liquid silicone-based adhesive of the present invention.

[0063] [Condensation-curing type liquid silicone-based adhesive]

[0064] The condensation-curing type liquid organosilicon adhesive is a liquid organosilicon adhesive that obtains a cured product by means of hydrolysis and condensation reactions caused by moisture (humidity) in the atmosphere at room temperature. In addition to the above-mentioned (A) hydroxide compound with a decomposition temperature of 180 to 600 °C, it also contains (B) a linear diorganopolysiloxane (base polymer) in which both ends of the molecular chain are capped with a hydroxyl group and / or a hydrolyzable silyl group bonded to a silicon atom, (C) a hydrolyzable organosilane compound having three or more hydrolyzable groups bonded to a silicon atom in the molecule and / or its partial hydrolysis condensate (crosslinking agent), (D) a curing catalyst, and (E) a silane coupling agent (adhesion-imparting agent).

[0065] As the condensation-curing type liquid organosilicon adhesive, it preferably contains:

[0066] (A) Hydroxide compound with a decomposition temperature of 180 to 600 °C: Its amount is 25 to 80% by mass of the whole adhesive,

[0067] (B) Linear diorganopolysiloxane in which both ends of the molecular chain are capped with a hydroxyl group and / or a hydrolyzable silyl group bonded to a silicon atom: 100 parts by mass,

[0068] (C) Hydrolyzable organosilane compound having three or more hydrolyzable groups bonded to a silicon atom in the molecule and / or its partial hydrolysis condensate: 0.1 to 40 parts by mass,

[0069] (D) Curing catalyst: 0.001 to 20 parts by mass, and

[0070] (E) Silane coupling agent: 0.05 to 20 parts by mass,

[0071] And it is a readily disintegratable condensation-curing type liquid organosilicon adhesive with the content of the material that generates heat by electromagnetic induction being 3% by mass or less.

[0072] (B) The organopolysiloxane as the base polymer (main agent) is a linear diorganopolysiloxane in which both ends of the molecular chain are capped with a hydroxyl group (silanol group) and / or a hydrolyzable silyl group bonded to a silicon atom. Among them, as the hydrolyzable silyl group, an alkoxysilyl group or an alkoxy-substituted alkoxysilyl group is preferred.

[0073] In the case of having a hydroxyl group (silanol group) bonded to a silicon atom, each of both ends of the molecular chain may have one hydroxyl group (i.e., hydroxysilyl group or silanol group) bonded to a silicon atom.

[0074] In the case where an alkoxysilyl group or an alkoxy-substituted alkoxysilyl group is present as a hydrolyzable silyl group at the terminal, two or three alkoxy groups (i.e., alkoxysilyl group) bonded to a silicon atom or an alkoxy-substituted alkoxy group bonded to a silicon atom (i.e., alkoxyalkoxysilyl group) can be present at each of the two terminals of the molecular chain (i.e., present as a dialkoxyorganosilyl group or bis(alkoxyalkoxy)organosilyl group, a trialkoxysilyl group or a tris(alkoxyalkoxy)silyl group).

[0075] As the alkoxy group, an alkoxy group having 1 to 10 carbon atoms, particularly 1 to 4 carbon atoms is preferred, and examples thereof include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, an isobutoxy group, a tert-butoxy group, a hexyloxy group, an octyloxy group and the like.

[0076] As the alkoxy-substituted alkoxy group, an alkoxy-substituted alkoxy group having 2 to 10 carbon atoms, particularly 2 to 4 carbon atoms is preferred, and examples thereof include a methoxyethoxy group, an ethoxyethoxy group, a methoxypropoxy group and the like.

[0077] As the linear diorganopolysiloxane having the two terminals of the molecular chain capped with a hydroxyl group and / or a hydrolyzable silyl group bonded to a silicon atom, it is particularly preferred that hydroxyl groups (silanol groups), methoxy groups or ethoxy groups are present at the two terminals of the diorganopolysiloxane, preferably only at the two terminals.

[0078] As the organic group bonded to a silicon atom other than a hydroxyl group and a hydrolyzable group, an unsubstituted or substituted monovalent hydrocarbon group having 1 to 18 carbon atoms, preferably 1 to 10 carbon atoms can be mentioned. Examples of the monovalent hydrocarbon group include alkyl groups such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a tert-butyl group, a hexyl group, a heptyl group, an octyl group, a 2-ethylhexyl group; cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group; alkenyl groups such as a vinyl group, an allyl group; aryl groups such as a phenyl group, a tolyl group, a naphthyl group; aralkyl groups such as a benzyl group, a phenylethyl group, a phenylpropyl group; groups obtained by substituting a part or all of the hydrogen atoms bonded to carbon atoms of these groups with halogen atoms such as fluorine, bromine, chlorine or a cyano group, for example, halogenated monovalent hydrocarbon groups such as a 3,3,3-trifluoropropyl group, a 3-chloropropyl group; cyanoalkyl groups such as a β-cyanoethyl group, a γ-cyanopropyl group. Among them, a methyl group is preferred.

[0079] The viscosity of the organopolysiloxane as the base polymer (main agent) at 23°C is preferably 50 to 1,000,000 mPa·s, more preferably 100 to 300,000 mPa·s. If the viscosity is less than the above lower limit value, sufficient mechanical properties may not be obtained in the resulting cured product. On the other hand, if it exceeds the above upper limit value, the workability may be reduced. Further, in the present invention, the viscosity is the value at 23°C measured using a rotational viscometer (for example, BL type, BH type, BS type, cone plate type, rheometer, etc.) (the same applies hereinafter).

[0080] As the base polymer (main agent), an organopolysiloxane can be used alone or in combination of two or more kinds.

[0081] The hydrolyzable organosilane compound and / or its partial hydrolysis condensate as the crosslinking agent (curing agent) (C) is a hydrolyzable organosilane compound and / or its partial hydrolysis condensate having three or more hydrolyzable groups bonded to silicon atoms in the molecule (that is, a siloxane compound such as a siloxane oligomer having three or more remaining hydrolyzable groups in the molecule). The component (C) functions as a crosslinking agent (curing agent) that hydrolyzes and condenses three or more hydrolyzable groups present in the molecule with a linear diorganopolysiloxane having hydroxyl groups and / or hydrolyzable silyl groups bonded to silicon atoms at both ends of the molecular chain to form a crosslinked structure.

[0082] Examples of the hydrolyzable groups of the hydrolyzable organosilane compound include alkoxy groups, alkoxy-substituted alkoxy groups, acyloxy groups, alkenyloxy groups, ketoxime groups, aminooxy groups, and acylamino groups having 1 to 10 carbon atoms. For example, alkoxy groups such as methoxy, ethoxy, and propoxy; alkoxy-substituted alkoxy groups such as methoxyethoxy, ethoxyethoxy, and methoxypropoxy; acyloxy groups such as acetoxy and octanoyloxy; alkenyloxy groups such as vinyloxy, isopropenyloxy, and 1-ethyl-2-methyldivinyloxy; ketoxime groups such as dimethylketoxime, methyl ethyl ketoxime, and methyl isobutyl ketoxime; aminooxy groups such as dimethylaminooxy and diethylaminooxy; and acylamino groups such as N-methylacetamido and N-ethylacetamido.

[0083] The hydrolyzable organosilane compound may have an organic group bonded to a silicon atom other than the above hydrolyzable groups. Examples of such an organic group bonded to a silicon atom other than the hydrolyzable groups include unsubstituted or substituted monovalent hydrocarbon groups having 1 to 18 carbon atoms, preferably 1 to 10 carbon atoms. For example, alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, hexyl, heptyl, octyl, 2-ethylhexyl, nonyl, decyl, and octadecyl; cycloalkyl groups such as cyclopentyl and cyclohexyl; alkenyl groups such as vinyl and allyl; aryl groups such as phenyl, tolyl, xylyl, and naphthyl; aralkyl groups such as benzyl, phenethyl, and phenylpropyl; and groups in which a part or all of the hydrogen atoms bonded to carbon atoms of these groups are substituted with halogen atoms such as fluorine, bromine, and chlorine or cyano groups, such as 3-chloropropyl and 3,3,3-trifluoropropyl. Among them, as the unsubstituted or substituted monovalent hydrocarbon group, methyl, ethyl, propyl, vinyl, and phenyl are preferred.

[0084] Examples of the hydrolyzable organosilane compound and its partial hydrolysis condensate include alkoxysilanes such as methyltrimethoxysilane, ethyltrimethoxysilane, decyltrimethoxysilane, vinyltrimethoxysilane, phenyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, vinyltriethoxysilane, phenyltriethoxysilane, vinyltris(1-cyclopenten-1-yloxy)silane, tetramethoxysilane, and tetraethoxysilane; ketoxime group-containing silanes such as methyltris(dimethylketoxime)silane, methyltris(methylethylketoxime)silane, ethyltris(methylethylketoxime)silane, methyltris(methylisobutylketoxime)silane, and vinyltris(methylethylketoxime)silane; alkoxy-substituted alkoxysilanes such as methyltris(methoxymethoxy)silane, ethyltris(methoxymethoxy)silane, vinyltris(methoxymethoxy)silane, phenyltris(methoxymethoxy)silane, methyltris(ethoxymethoxy)silane, ethyltris(ethoxymethoxy)silane, vinyltris(ethoxymethoxy)silane, phenyltris(ethoxymethoxy)silane, tetrakis(methoxymethoxy)silane, and tetrakis(ethoxymethoxy)silane; aminooxy group-containing silanes such as methyltris(N,N-diethylaminooxy)silane; acylamino group-containing silanes such as methyltris(N-methylacetamido)silane, methyltris(N-butylacetamido)silane, and methyltris(N-cyclohexylacetamido)silane; alkenyloxy group-containing silanes such as methyltriisopropenyloxy silane, vinyltriisopropenyloxy silane, and phenyltriisopropenyloxy silane; acyloxy group-containing silanes such as methyltriacetoxysilane and vinyltriacetoxysilane, and partial hydrolysis condensates of these hydrolyzable organosilane compounds.

[0085] The hydrolyzable organosilane compound as a crosslinking agent (curing agent) is significantly different from the (E) silane coupling agent as an adhesion promoter described later in that it does not have a monovalent hydrocarbon group substituted with a functional group having a heteroatom such as a nitrogen atom, an oxygen atom, or a sulfur atom in the molecule.

[0086] The hydrolyzable organosilane compound and / or its partial hydrolysis condensate may be used alone or in combination of two or more.

[0087] The compounding amount of the hydrolyzable organosilane compound and / or its partial hydrolysis condensate as a crosslinking agent (curing agent) is 0.1 to 40 parts by mass, preferably 1 to 20 parts by mass, based on 100 parts by mass of a linear diorganopolysiloxane having hydroxyl groups bonded to silicon atoms and / or hydrolyzable silyl groups at both ends of the molecular chain. If the amount of the hydrolyzable organosilane compound and / or its partial hydrolysis condensate is less than the above lower limit value (0.1 part by mass), the curability and storage stability may be reduced. In addition, if it exceeds the above upper limit value (40 parts by mass), not only is it disadvantageous in terms of price, but also the elongation of the cured product obtained may be reduced, or the durability may be reduced.

[0088] (D) The curing catalyst can use the condensation catalysts that have been generally used as the curing accelerators for condensation-curing liquid silicone adhesives (room-temperature-curing organopolysiloxane compositions). For example, organotin compounds such as dibutylmethoxytin, dibutyltin diacetate, dibutyltin dioctoate, dibutyltin dilaurate, dioctyltin dilaurate, dioctyltin dioctoate, dioctyltin dineodecanoate, dimethyldimethoxytin, and dimethyltin diacetate can be cited; organotitanium compounds such as tetrapropyl titanate, tetrabutyl titanate, tetra-2-ethylhexyl titanate, diisopropoxytitanium bis(ethyl acetoacetate), and dimethoxydi(acetylacetone)titanium; amine compounds such as hexylamine and tetramethylguanidylpropyltrimethoxysilane, and their salts, etc. One of these can be used alone, or two or more of them can be used in combination.

[0089] Regarding the compounding amount of the curing catalyst, it is 0.001 to 20 parts by mass, preferably 0.005 to 5 parts by mass, and more preferably 0.01 to 2 parts by mass, relative to 100 parts by mass of the linear diorganopolysiloxane having the molecular chain terminals blocked with hydroxyl groups and / or hydrolyzable silyl groups bonded to silicon atoms. If the compounding amount of the curing catalyst is less than the above lower limit value (0.001 part by mass), the catalytic effect may sometimes not be obtained. In addition, if the compounding amount of the curing catalyst exceeds the above upper limit value (20 parts by mass), not only is it disadvantageous in terms of price, but sometimes the durability of the composition is reduced, or sometimes the adhesiveness is reduced.

[0090] In the condensation-curing liquid silicone adhesive, a silane coupling agent (a hydrolyzable silane compound having a monovalent hydrocarbon group substituted with a functional group having a heteroatom such as a nitrogen atom, an oxygen atom, or a sulfur atom (however, excluding the guanidyl group) in the molecule, a so-called carbon-functional silane compound), which can improve the adhesive strength and also acts as an adhesiveness-imparting component, is added as the (E) component.

[0091] As the silane coupling agent acting as the adhesiveness-imparting component, a silane coupling agent known in the art is preferably used. In particular, as the hydrolyzable group, a group having an alkoxy or alkenyloxy group is preferred. Specifically, alkoxy groups such as methoxy, ethoxy, and propoxy, and alkenyloxy groups such as vinyloxy, isopropenyloxy, and 1-ethyl-2-methylvinyloxy can be cited.

[0092] In addition, as the monovalent hydrocarbon group substituted with a functional group having a heteroatom such as a nitrogen atom, an oxygen atom, or a sulfur atom (however, excluding a guanidyl group), a monovalent hydrocarbon group having 1 to 20 carbon atoms having at least one unsubstituted or substituted amino group, unsubstituted or substituted imino group, mercapto group, epoxy group, (meth)acryloyloxy group, etc. is preferred. Specifically, γ-acryloyloxypropyl, γ-methacryloyloxypropyl, β-(3,4-epoxycyclohexyl)ethyl, γ-glycidoxypropyl, N-β(aminoethyl)γ-aminopropyl, γ-aminopropyl, and the group represented by the following formula

[0093] [Chemical formula 1]

[0094]

[0095] can be exemplified.

[0096] The silane coupling agent may have an organic group bonded to a silicon atom other than the monovalent hydrocarbon group substituted with the above hydrolyzable group and functional group. As the organic group bonded to a silicon atom other than the monovalent hydrocarbon group substituted with such a hydrolyzable group and functional group, a monovalent hydrocarbon group having 1 to 10 carbon atoms is preferred. For example, alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, hexyl, heptyl, and octyl; cycloalkyl groups such as cyclopentyl and cyclohexyl; alkenyl groups such as vinyl and allyl; aryl groups such as phenyl, tolyl, and xylyl; aralkyl groups such as benzyl and phenethyl, etc. Among them, methyl and ethyl are preferred.

[0097] Specifically, as the silane coupling agent, γ-acryloyloxypropyltrimethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, N-β(aminoethyl)γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, and the silane compound represented by the following formula

[0098] [Chemical formula 2]

[0099]

[0100] can be exemplified. γ-mercaptopropyltrimethoxysilane, γ-glycidoxypropyltriisopropenyloxysilane, γ-glycidoxypropylmethyldiisopropenyloxysilane, etc. are particularly preferably used. A silane coupling agent containing an amino group is particularly preferably used.

[0101] The silane coupling agent may be used alone or in combination of two or more.

[0102] (E) The compounding amount of the silane coupling agent is 0.05 to 20 parts by mass, preferably 0.1 to 15 parts by mass, and particularly preferably 0.5 to 10 parts by mass, relative to 100 parts by mass of the linear diorganopolysiloxane having the molecular chain terminals blocked with hydroxyl groups and / or hydrolyzable silyl groups bonded to silicon atoms. If it is less than 0.05 part by mass, sufficient adhesiveness cannot be obtained, and if it exceeds 20 parts by mass, the weather resistance and mechanical properties of the obtained cured product are poor.

[0103] In the condensation-curing type liquid organosilicon-based adhesive, in addition to the above components, optional components can be compounded within the range not impairing the object of the present invention. Examples of such optional components include inorganic fillers other than the component (A), colorants such as pigments, dyes, and fluorescent brighteners; antibacterial agents; antifungal agents; plasticizers such as silicone oils (non-functional organopolysiloxanes).

[0104] Specific examples of the inorganic filler other than the component (A) as the optional component include carbon such as acetylene black, dry-process silica (such as fumed silica), wet-process silica (such as precipitated silica), quartz fine powder, diatomaceous earth powder, particulate alumina, magnesium oxide powder, colloidal calcium carbonate, calcium carbonate such as heavy calcium carbonate, and finely powdered inorganic fillers (excluding the component (A)) surface-treated with silanes, silazanes, low-polymerization-degree polysiloxanes, etc.

[0105] When compounding an inorganic filler other than the component (A), its compounding amount is preferably 0.1 to 800 parts by mass, more preferably 0.5 to 600 parts by mass, relative to 100 parts by mass of the linear diorganopolysiloxane having the molecular chain terminals blocked with hydroxyl groups and / or hydrolyzable silyl groups bonded to silicon atoms.

[0106] The condensation-curing type liquid organosilicon-based adhesive can be prepared by uniformly mixing the above components in a moisture-blocking state (in a dry atmosphere or under reduced pressure) using a known mixer according to a conventional method.

[0107] In addition, the obtained condensation-curing type liquid organosilicon-based adhesive is cured, for example, by standing at room temperature (23°C ± 15°C), and its molding method, curing conditions, etc. can adopt known methods and conditions corresponding to the type of the condensation-curing type liquid organosilicon-based adhesive. For example, it can be cured by standing in the atmosphere at 23°C / 50% RH for several hours to several days (for example, 6 hours to 7 days).

[0108] [Addition-reaction curing type liquid organosilicon-based adhesive]

[0109] The addition reaction-curable liquid silicone-based adhesive contains, in addition to the above-mentioned (A) hydroxide compound having a decomposition temperature of 180 to 600 °C, (F) an alkenyl-containing organopolysiloxane (base polymer) having an alkenyl such as vinyl bonded to a silicon atom at the molecular chain end, (G) an organohydrogenpolysiloxane (crosslinking agent) having at least two hydrogen atoms (SiH groups) bonded to silicon atoms in the molecule, (H) a platinum group metal catalyst (hydrosilylation addition reaction catalyst), and (I) an adhesion promoter, and is a liquid silicone-based adhesive that is crosslinked by the addition reaction (hydrosilylation reaction) of the SiH group and vinyl to obtain a cured product.

[0110] As the addition reaction-curable liquid silicone-based adhesive, it is preferably contained:

[0111] (A) Hydroxide compound having a decomposition temperature of 180 to 600 °C: Its amount is 25 to 80% by mass of the whole adhesive,

[0112] (F) Alkenyl-containing organopolysiloxane having an alkenyl bonded to a silicon atom at the molecular chain end: 100 parts by mass,

[0113] (G) Organohydrogenpolysiloxane having at least two hydrogen atoms bonded to silicon atoms in the molecule: Its amount is such that, relative to 1 mole of the alkenyl bonded to a silicon atom in the (F) component, the hydrogen atom bonded to a silicon atom is 0.01 to 3 moles,

[0114] (H) Platinum group metal catalyst: Relative to the total amount of the (F) component and the (G) component, in terms of the mass conversion of platinum group metal atoms, it is 0.01 to 1000 ppm, and

[0115] (I) Adhesion promoter: 0.05 to 20 parts by mass,

[0116] And it is a readily disintegratable addition reaction-curable liquid silicone-based adhesive with the content of the material that generates heat by electromagnetic induction being 3% by mass or less.

[0117] The alkenyl-containing organopolysiloxane as the (F) base polymer (main agent) is a linear diorganopolysiloxane terminated at the molecular chain ends (single-end or both ends of the molecular chain) with a silyl group having an alkenyl group such as vinyl bonded to a silicon atom, and is an organopolysiloxane having an average of at least 1, preferably 2 or more (usually 2 to 20, especially 2 to 10, and further about 2 to 5) alkenyl groups bonded to silicon atoms in the molecule. Examples of such alkenyl groups include lower alkenyl groups having usually 2 to 6 carbon atoms, preferably about 2 to 4 carbon atoms, such as vinyl, allyl, propenyl, isopropenyl, butenyl, hexenyl, and cyclohexenyl. Further, as long as the alkenyl-containing organopolysiloxane as the base polymer (main agent) has an alkenyl group bonded to a silicon atom at the single-end or both ends of the molecular chain, it may have an alkenyl group in the side chain of the molecular chain.

[0118] In addition, the organic groups bonded to silicon atoms other than the alkenyl groups bonded to silicon atoms are not particularly limited as long as they do not have an aliphatic unsaturated bond. Examples include unsubstituted or substituted monovalent hydrocarbon groups having usually 1 to 12, preferably 1 to 10 carbon atoms and not including aliphatic unsaturated bonds. Examples of such unsubstituted or substituted monovalent hydrocarbon groups include alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, and heptyl; cycloalkyl groups such as cyclohexyl; aryl groups such as phenyl, tolyl, xylyl, and naphthyl; aralkyl groups such as benzyl and phenethyl; and halogenated alkyl groups such as chloromethyl, 3-chloropropyl, and 3,3,3-trifluoropropyl in which a part or all of the hydrogen atoms of these groups are substituted with halogen atoms such as chlorine, fluorine, and bromine atoms. Preferred are alkyl groups and aryl groups, and more preferred are methyl and phenyl.

[0119] As specific examples of the organopolysiloxane containing an alkenyl group, there may be mentioned dimethylpolysiloxane terminated with dimethylethenylsilanoxy groups at both ends, dimethylsiloxane-methylvinylsiloxane copolymer terminated with dimethylethenylsilanoxy groups at both ends, dimethylsiloxane-diphenylsiloxane copolymer terminated with dimethylethenylsilanoxy groups at both ends, dimethylsiloxane-methylvinylsiloxane-diphenylsiloxane copolymer terminated with dimethylethenylsilanoxy groups at both ends, methyltrifluoropropylpolysiloxane terminated with dimethylethenylsilanoxy groups at both ends, dimethylsiloxane-methyltrifluoropropylsiloxane copolymer terminated with dimethylethenylsilanoxy groups at both ends, dimethylsiloxane-methyltrifluoropropylsiloxane-methylvinylsiloxane copolymer terminated with dimethylethenylsilanoxy groups at both ends, dimethylpolysiloxane terminated with methyldivinylsilanoxy groups at both ends, dimethylsiloxane-methylvinylsiloxane copolymer terminated with methyldivinylsilanoxy groups at both ends, dimethylsiloxane-diphenylsiloxane copolymer terminated with methyldivinylsilanoxy groups at both ends, dimethylsiloxane-methylvinylsiloxane-diphenylsiloxane copolymer terminated with methyldivinylsilanoxy groups at both ends, methyltrifluoropropylpolysiloxane terminated with methyldivinylsilanoxy groups at both ends, dimethylsiloxane-methyltrifluoropropylsiloxane copolymer terminated with methyldivinylsilanoxy groups at both ends, dimethylsiloxane-methyltrifluoropropylsiloxane-methylvinylsiloxane copolymer terminated with methyldivinylsilanoxy groups at both ends, dimethylpolysiloxane terminated with trivinylsilanoxy groups at both ends, dimethylsiloxane-methylvinylsiloxane copolymer terminated with trivinylsilanoxy groups at both ends, dimethylsiloxane-diphenylsiloxane copolymer terminated with trivinylsilanoxy groups at both ends, dimethylsiloxane-methylvinylsiloxane-diphenylsiloxane copolymer terminated with trivinylsilanoxy groups at both ends, methyltrifluoropropylpolysiloxane terminated with trivinylsilanoxy groups at both ends, dimethylsiloxane-methyltrifluoropropylsiloxane copolymer terminated with trivinylsilanoxy groups at both ends, dimethylsiloxane-methyltrifluoropropylsiloxane-methylvinylsiloxane copolymer terminated with trivinylsilanoxy groups at both ends, dimethylpolysiloxane terminated with trimethylsilanoxy group at one end and dimethylethenylsilanoxy group at the other end, dimethylsiloxane-methylvinylsiloxane copolymer terminated with trimethylsilanoxy group at one end and dimethylethenylsilanoxy group at the other end, dimethylsiloxane-diphenylsiloxane copolymer terminated with trimethylsilanoxy group at one end and dimethylethenylsilanoxy group at the other end, dimethylsiloxane-methylvinylsiloxane-diphenylsiloxane copolymer terminated with trimethylsilanoxy group at one end and dimethylethenylsilanoxy group at the other end, methyltrifluoropropylpolysiloxane terminated with trimethylsilanoxy group at one end and dimethylethenylsilanoxy group at the other end,A dimethylsiloxane-methyltrifluoropropylsiloxane copolymer capped at one end with trimethylsilyloxy and at the other end with dimethylethenylsilyloxy, a dimethylsiloxane-methyltrifluoropropylsiloxane-methylvinylsiloxane copolymer capped at one end with trimethylsilyloxy and at the other end with dimethylethenylsilyloxy, etc.

[0120] The viscosity at 23 °C of the alkenyl-containing organopolysiloxane as the base polymer (main agent) is preferably 100 to 500,000 mPa·s, more preferably 700 to 100,000 mPa·s.

[0121] As the base polymer (main agent), the alkenyl-containing organopolysiloxane can be used alone or in combination of two or more.

[0122] The organohydrogenpolysiloxane as the (G) crosslinking agent (curing agent) has on average at least 2, preferably at least 3, more preferably an upper limit of 500, further preferably an upper limit of 200, and particularly preferably an upper limit of 100 hydrogen atoms (SiH groups) bonded to silicon atoms in the molecule, and preferably does not have aliphatic unsaturated bonds in the molecule.

[0123] In this organohydrogenpolysiloxane, there is no particular limitation on the organic groups bonded to silicon atoms other than the hydrogen atoms bonded to silicon atoms. For example, unsubstituted or substituted monovalent hydrocarbon groups having usually 1 to 10, preferably 1 to 6 carbon atoms can be cited. As specific examples, the same groups as those exemplified for the organic groups bonded to silicon atoms other than the alkenyl groups bonded to silicon atoms in the description of the alkenyl-containing organopolysiloxane, alkenyl groups such as vinyl and allyl, etc. are cited. Unsubstituted monovalent hydrocarbon groups without aliphatic unsaturated bonds such as alkyl and aryl groups are preferred, and methyl, phenyl, etc. are more preferred.

[0124] Regarding the number of silicon atoms in the molecule, an organohydrogenpolysiloxane that is liquid at room temperature and has 2 to 300, particularly 3 to 150, especially about 4 to 100 silicon atoms is preferably used. Further, the hydrogen atoms bonded to silicon atoms can be located at either the end of the molecular chain or in the middle (non-terminal) of the molecular chain, or at both. In addition, the molecular structure of the organohydrogenpolysiloxane can be any of linear, cyclic, branched-chain, and three-dimensional network structures. In the present invention, the degree of polymerization (or the number of repeating units of the diorganosiloxane unit constituting the main chain as a measure of the number of silicon atoms in the molecule) can be determined, for example, by using toluene or the like as an elution solvent and calculating the number-average degree of polymerization (or number-average molecular weight) in terms of polystyrene in gel permeation chromatography (GPC) analysis.

[0125] As the organohydrogenpolysiloxane, for example, 1,1,3,3 - tetramethyldisiloxane, 1,3,5,7 - tetramethylcyclotetrasiloxane, tris(hydrodimethoxysilyloxy)methylsilane, tris(hydrodimethoxysilyloxy)phenylsilane, methylhydrogencyclopolysiloxane, methylhydrogensiloxane - dimethylsiloxane cyclic copolymer, dimethylsiloxane - methylhydrogensiloxane copolymer capped with trimethylsilyloxy groups at both ends, dimethylpolysiloxane capped with dimethylhydroxysilyloxy groups at both ends, dimethylsiloxane - methylhydrogensiloxane copolymer capped with dimethylhydroxysilyloxy groups at both ends, methylhydrogensiloxane - diphenylsiloxane copolymer capped with trimethylsilyloxy groups at both ends, methylhydrogensiloxane - diphenylsiloxane - dimethylsiloxane copolymer capped with trimethylsilyloxy groups at both ends, methylhydrogensiloxane - methylphenylsiloxane - dimethylsiloxane copolymer capped with trimethylsilyloxy groups at both ends, methylhydrogensiloxane - dimethylsiloxane - diphenylsiloxane copolymer capped with dimethylhydroxysilyloxy groups at both ends, methylhydrogensiloxane - dimethylsiloxane - methylphenylsiloxane copolymer capped with dimethylhydroxysilyloxy groups at both ends, copolymers composed of (CH3)2HSiO 1 / 2 units and (CH3)3SiO 1 / 2 units and SiO 4 / 2 units, copolymers composed of (CH3)2HSiO 1 / 2 units and SiO 4 / 2 units, copolymers composed of (CH3)2HSiO 1 / 2 units and SiO 4 / 2 units and (C6H5)SiO 3 / 2 units, products obtained by replacing part or all of the methyl groups in these exemplified compounds with other alkyl groups, phenyl groups, etc. Further, the organohydrogenpolysiloxane in the component (G) having at least two hydrogen atoms bonded to silicon atoms in the molecule is significantly different from the adhesion - imparting agent of the component (I) described later in that the silicon - atom - bonded organic groups other than the hydrogen atoms bonded to silicon atoms in the molecule do not have functional groups such as epoxy groups and alkoxysilyl groups.

[0126] The organohydrogenpolysiloxane may be used alone or in combination of two or more.

[0127] The addition amount of the organohydrogenpolysiloxane is as follows: relative to 1 mole of the alkenyl group bonded to silicon atom in the organopolysiloxane containing alkenyl group, the hydrogen atom bonded to silicon atom (SiH group) is 0.01 - 3 moles, preferably 0.05 - 2.5 moles, more preferably 0.2 - 2 moles.

[0128] (H) A platinum group metal catalyst (hydrosilylation addition reaction catalyst) is used as a catalyst for promoting the addition reaction of the vinyl group bonded to the silicon atom in the organopolysiloxane containing vinyl and the hydrogen atom bonded to the silicon atom in the organohydrogenpolysiloxane. This platinum group metal catalyst can use known catalysts. As specific examples thereof, platinum black, chloroplatinic acid, alcohol-modified products such as chloroplatinic acid, and platinum-based catalysts such as complexes of chloroplatinic acid with olefins, aldehydes, vinylsiloxanes, or acetylenic alcohols can be exemplified.

[0129] The compounding amount of the platinum group metal catalyst can be an effective amount, which can be appropriately increased or decreased according to the required curing speed. In terms of the mass conversion of platinum group metal atoms, it is usually in the range of 0.01 to 1000 ppm, preferably 0.1 to 500 ppm, and more preferably 1 to 300 ppm, based on the total amount of the organopolysiloxane containing vinyl and the organohydrogenpolysiloxane. If the compounding amount is too large, the heat resistance of the obtained cured product may sometimes decrease.

[0130] (I) The component is an adhesion promoter that gives self-adhesion to the composition of the present invention. This self-adhesion is particularly preferably good for metals and organic resins. As the component (I), for example, organosilanes having at least one, preferably two or more functional groups selected from vinyl and other alkenyl groups, (meth)acryloyloxy groups, hydrosilyl groups (SiH groups), epoxy groups, alkoxysilyl groups, carbonyl groups, and phenyl groups, cyclic or linear organopolysiloxanes having 2 to 30 silicon atoms, preferably about 4 to 20 silicon atoms, and other functional group-containing organosilicon compounds (however, excluding components (F) and (G)), and non-silicon-based (i.e., hydrocarbon compounds containing no silicon atoms in the molecule) hydrocarbon compounds containing 1 to 4, preferably 1 to 2, 1 to 4-valent, preferably 2 to 4-valent phenylene structures and other aromatic rings in one molecule and containing at least 1, preferably 2 to 4 functional groups (such as alkenyl groups, (meth)acryloyloxy groups) that can contribute to the hydrosilylation addition reaction in one molecule and may contain oxygen atoms in the molecule can be cited.

[0131] As such a component (I), specifically, in addition to the functional group-containing organoalkoxysilanes and functional group-containing organohydrogenpolysiloxanes exemplified below, and functional group-containing organosilicon compounds in which the total number of repetitions of the difunctional siloxane units in the functional group-containing linear organohydrogenpolysiloxanes exemplified below is any positive integer in the range of 3 to 28, derivatives in which the hydroxyl groups at both ends of the molecular chain of bisphenol compounds (bisphenol F, bisphenol A, bisphenol AF, etc.) or their oligomers are substituted with alkenyloxy or (meth)acryloyloxy and blocked with alkoxy groups can be cited.

[0132] [Chemical formula 3]

[0133]

[0134] [Chemical Formula 4]

[0135]

[0136] (I) component can be used alone or in combination of two or more. From the aspect of adhesion to the substrate, it is preferred to use a silicone compound in combination with a non-silicon organic compound.

[0137] (I) The compounding amount of the component is an amount that the composition of the present invention can obtain good self-adhesion to the adherend, especially metals and organic resins. For 100 parts by mass of the (F) component, it is, for example, 0.05 to 20 parts by mass, more preferably 0.1 to 15 parts by mass, and particularly preferably 0.5 to 10 parts by mass. If it is less than 0.05 parts by mass, sufficient adhesion may not be obtained. If it exceeds 20 parts by mass, the weather resistance and mechanical properties of the obtained cured product may be poor.

[0138] In the addition reaction curable liquid silicone-based adhesive, in addition to the above components, optional components can be compounded within the range not impairing the object of the present invention. Examples of such optional components include reaction inhibitors, inorganic fillers similar to those exemplified in the above condensation curable liquid silicone-based adhesive (however, excluding the hydroxide compound with a decomposition temperature of 180 to 600 °C of the (A) component), organopolysiloxane without hydrogen atoms bonded to silicon atoms (SiH groups) and alkenyl groups bonded to silicon atoms (so-called non-functional silicone oil), heat-resistant additives, flame retardancy imparting agents, thixotropy imparting agents, pigments, dyes, etc.

[0139] The addition reaction curable liquid silicone-based adhesive can be prepared by uniformly mixing the above components using a known mixer according to a conventional method.

[0140] In addition, as the curing conditions of the addition reaction curable liquid silicone-based adhesive, it can be set at 23 to 150 °C, especially 10 minutes to 8 hours at 23 to 100 °C, especially 30 minutes to 5 hours.

[0141] [UV curable liquid silicone-based adhesive]

[0142] The UV curable liquid silicone-based adhesive contains, in addition to the above-mentioned (A) hydroxide compound with a decomposition temperature of 180 to 600 °C, a (J) UV-reactive organopolysiloxane (base polymer) and a (K) photoinitiator, and is a liquid silicone-based adhesive that is crosslinked by UV irradiation to obtain a cured product.

[0143] As the UV curable liquid silicone-based adhesive, it is preferably contained:

[0144] (A) A hydroxide compound having a decomposition temperature of 180 to 600 °C: Its amount is 25 to 80% by mass of the total binder,

[0145] (J) An ultraviolet-reactive organopolysiloxane: 100 parts by mass, and

[0146] (K) A photoinitiator: 0.01 to 10 parts by mass,

[0147] And a readily decomposable ultraviolet-curable liquid silicone-based adhesive in which the content of the material that generates heat by electromagnetic induction is 3% by mass or less.

[0148] (J) The ultraviolet-reactive organopolysiloxane of the component is not particularly limited as long as it generally functions as a base polymer in an ultraviolet-curable silicone composition, and is preferably an organopolysiloxane having at least 2, more preferably 2 to 20, and particularly preferably 2 to 10 ultraviolet-reactive groups in one molecule. The multiple ultraviolet-reactive groups present in the organopolysiloxane may all be the same or different.

[0149] Examples of the ultraviolet-reactive group include alkenyl groups such as vinyl, allyl, and propenyl; alkenyloxy groups such as vinyloxy, allyloxy, propenyloxy, and isopropenyloxy; aliphatic unsaturated groups other than alkenyl groups such as acryloyl and methacryloyl; epoxy groups; and hydrosilyl groups. Preferably, acryloyl, methacryloyl, mercapto, epoxy, and hydrosilyl groups can be cited, and more preferably, acryloyl and methacryloyl groups can be cited.

[0150] In addition, the organic group bonded to the silicon atom other than the silicon atom-bonded alkenyl group is not particularly limited as long as it does not have an aliphatic unsaturated bond. For example, an unsubstituted or substituted monovalent hydrocarbon group having usually 1 to 12, preferably 1 to 10 carbon atoms and not including an aliphatic unsaturated bond can be cited. Examples of the unsubstituted or substituted monovalent hydrocarbon group include alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, and heptyl; cycloalkyl groups such as cyclohexyl; aryl groups such as phenyl, tolyl, xylyl, and naphthyl; aralkyl groups such as benzyl and phenethyl; and haloalkyl groups such as chloromethyl, 3-chloropropyl, and 3,3,3-trifluoropropyl in which a part or all of the hydrogen atoms of these groups are substituted by halogen atoms such as chlorine, fluorine, and bromine atoms. Alkyl groups and aryl groups are preferred, and methyl and phenyl are more preferred.

[0151] Specific examples of the organopolysiloxane containing an ultraviolet-reactive group include dimethylpolysiloxane terminated with dimethylethenylsilanoxy groups at both ends, dimethylsiloxane-methylvinylsiloxane copolymer terminated with dimethylethenylsilanoxy groups at both ends, dimethylsiloxane-diphenylsiloxane copolymer terminated with dimethylethenylsilanoxy groups at both ends, dimethylpolysiloxane terminated with dimethylacrylsilanoxy groups at both ends, dimethylsiloxane-methylvinylsiloxane copolymer terminated with dimethylacrylsilanoxy groups at both ends, dimethylsiloxane-diphenylsiloxane copolymer terminated with dimethylacrylsilanoxy groups at both ends, dimethylpolysiloxane terminated with dimethylmethacrylsilanoxy groups at both ends, dimethylsiloxane-methylvinylsiloxane copolymer terminated with dimethylmethacrylsilanoxy groups at both ends, dimethylsiloxane-diphenylsiloxane copolymer terminated with dimethylmethacrylsilanoxy groups at both ends, dimethylpolysiloxane terminated with dimethylmercaptosilanoxy groups at both ends, dimethylsiloxane-methylvinylsiloxane copolymer terminated with dimethylmercaptosilanoxy groups at both ends, dimethylsiloxane-diphenylsiloxane copolymer terminated with dimethylmercaptosilanoxy groups at both ends, dimethylpolysiloxane terminated with dimethyloxiranesilanoxy groups at both ends, dimethylsiloxane-methylvinylsiloxane copolymer terminated with dimethyloxiranesilanoxy groups at both ends, dimethylsiloxane-diphenylsiloxane copolymer terminated with dimethyloxiranesilanoxy groups at both ends, dimethylpolysiloxane terminated with methyldivinylsilanoxy groups at both ends, dimethylsiloxane-methylvinylsiloxane copolymer terminated with methyldivinylsilanoxy groups at both ends, dimethylsiloxane-diphenylsiloxane copolymer terminated with methyldivinylsilanoxy groups at both ends, dimethylpolysiloxane terminated with methyldiacrylsilanoxy groups at both ends, dimethylsiloxane-methylvinylsiloxane copolymer terminated with methyldiacrylsilanoxy groups at both ends, dimethylsiloxane-diphenylsiloxane copolymer terminated with methyldiacrylsilanoxy groups at both ends, dimethylpolysiloxane terminated with trivinylsilanoxy groups at both ends, dimethylsiloxane-methylvinylsiloxane copolymer terminated with trivinylsilanoxy groups at both ends, dimethylsiloxane-diphenylsiloxane copolymer terminated with trivinylsilanoxy groups at both ends, dimethylpolysiloxane with one end terminated with trimethylsilanoxy and the other end terminated with dimethylethenylsilanoxy, dimethylsiloxane-methylvinylsiloxane copolymer with one end terminated with trimethylsilanoxy and the other end terminated with dimethylethenylsilanoxy, dimethylsiloxane-diphenylsiloxane copolymer with one end terminated with trimethylsilanoxy and the other end terminated with dimethylethenylsilanoxy, and the like.

[0152] The viscosity of the ultraviolet-reactive organopolysiloxane at 23°C is preferably 100 to 500,000 mPa·s, more preferably 700 to 100,000 mPa·s.

[0153] The ultraviolet-reactive organopolysiloxane can be used alone or in combination of two or more.

[0154] (K) The photoinitiator has the effect of promoting the photopolymerization of the ultraviolet-reactive group in the (J) component. There is no particular limitation on the (K) component. Specific examples thereof include acetophenone, propiophenone, benzophenone, xanthenol, fluorescein, benzaldehyde, anthraquinone, triphenylamine, 4-methylacetophenone, 3-pentylacetophenone, 4-methoxyacetophenone, 3-bromoacetophenone, 4-allylacetophenone, p-diacetylbenzene, 3-methoxybenzophenone, 4-methylbenzophenone, 4-chlorobenzophenone, 4,4'-dimethoxybenzophenone, 4-chloro-4'-benzylbenzophenone, 3-chloroxanthone, 3,9-dichloroxanthone, 3-chloro-8-nonylxanthone, benzoin, benzoin methyl ether, benzoin butyl ether, bis(4-dimethylaminophenyl) ketone, benzyl methyl acetal, 2-chlorothioxanthone, diethylacetophenone, 1-hydroxy-1-chlorophenyl ketone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-(4-(methylthio)phenyl)-2-morpholino-1-propanone, 2,2-dimethoxy-2-phenylacetophenone, diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, etc. Preferably, from the viewpoint of high purity, benzophenone, 4-methoxyacetophenone, 4-methylbenzophenone, diethoxyacetophenone, 1-hydroxycyclohexyl phenyl ketone, and 2-hydroxy-2-methyl-1-phenylpropan-1-one can be mentioned. More preferably, diethoxyacetophenone, 1-hydroxycyclohexyl phenyl ketone, and 2-hydroxy-2-methyl-1-phenylpropan-1-one can be mentioned.

[0155] These photoinitiators can be used alone or in combination of two or more.

[0156] There is no particular limitation on the addition amount of the (K) component. Relative to 100 parts by mass of the (J) component, it is preferably 0.01 to 10 parts by mass, more preferably 0.1 to 3 parts by mass, and further preferably 0.5 to 3 parts by mass. If the addition amount of the (K) component is within this range, it is easy to control the curing of the ultraviolet-curable liquid silicone adhesive.

[0157] The ultraviolet-curable liquid silicone adhesive can also use a liquid silicone adhesive having both ultraviolet-curable and condensation-curable types, or a liquid silicone adhesive having both ultraviolet-curable and addition-curable types.

[0158] The liquid silicone-based adhesive having both a UV-curable type and a condensation-curable type uses the above-mentioned (A) hydroxide compound having a decomposition temperature of 180 to 600 °C, and also uses the above-mentioned (B) component, (J) component as the base polymer, the above-mentioned (C) component as the curing agent, a component having both a substituent that reacts with UV light and a condensable substituent, the above-mentioned (D) component as the condensation-curing catalyst, the above-mentioned (K) component as the UV-curing catalyst, and the above-mentioned (E) component as the adhesion-imparting component.

[0159] The liquid silicone-based adhesive having both a UV-curable type and an addition-curable type uses the above-mentioned (A) hydroxide compound having a decomposition temperature of 180 to 600 °C, and also uses the above-mentioned (F) component, (J) component as the base polymer, the above-mentioned (G) component as the curing agent, the above-mentioned (H) component as the addition-curing catalyst, the above-mentioned (K) component as the UV-curing catalyst, and the above-mentioned (I) component as the adhesion-imparting component.

[0160] The UV-curable liquid silicone-based adhesive can be prepared by uniformly mixing the above-mentioned components using a known mixer according to a conventional method.

[0161] The UV-curable liquid silicone-based adhesive cures by irradiating UV light. There are no particular limitations on the UV irradiation conditions. It is preferable to use a UV light-emitting diode having an emission wavelength of 365 nm, and the illuminance is 5 to 500 mW / cm 2 , preferably 10 to 200 mW / cm 2 , and the light quantity is 0.5 to 100 J / cm 2 , preferably 10 to 50 J / cm 2 .

[0162] [Bonding member]

[0163] In the method for disassembling the bonding member of the present invention, the bonding member is formed by curing a curable liquid silicone-based adhesive containing a specific amount of a hydroxide compound having a decomposition temperature of 180 to 600 °C and having a content of a material that generates heat by electromagnetic induction of 3% by mass or less (a bonding member composed of a cured adhesive silicone rubber) to bond between a plurality of (especially two) members of a member having at least a part of the bonding interface being metal. The members can be the same or different members.

[0164] In this bonding member, one of the bonded members uses a member having at least a part of the bonding interface being metal, and the other member uses a member selected from the same member as it (a member having at least a part of the bonding interface being metal), an organic resin member, and a metal member.

[0165] A member in which at least a part of the joining interface is metal only needs to have metal at least at the joining interface, and it may also be entirely metal. Furthermore, the metal of the joining interface of this member only needs to be an area that can be sufficiently heated by electromagnetic induction.

[0166] Specific examples of a member in which at least a part of the joining interface is metal include automotive parts and electrical and electronic parts made of aluminum alloys such as A1050, A2017, A5052, A5083, A6061, A1N30, etc., aluminum alloy die-castings such as ADC1, ADC3, ADC10, ADC12, ADC14, etc., carbon steels such as SPCC, SS400, SAPH, etc., stainless steels such as SUS304, SUS430, etc., and magnesium alloys such as AZ-91D, AM50A, etc.

[0167] As long as the metal of a member in which at least a part of the joining interface is metal and a metal member can generate heat by electromagnetic induction, it can be a magnetic material or a non-magnetic material. For example, pure metals such as aluminum, iron, and copper, alloys containing them (aluminum alloys (aluminum alloy die-castings such as Al-Cu-Si series alloy (ADC12)), carbon steels (such as SPCC, SS400, SAPH), cast iron (Fe-Si-C ternary alloy), stainless steel (especially ferritic), copper alloys (brass, bronze, cupronickel), nickel-chromium alloy, magnesium alloys (such as AZ-91D, AM50A), titanium alloys, etc.) can be cited. It should be noted that a magnetic material refers to a metal material in which the ratio of the magnetic permeability in vacuum (μ0) to the initial magnetic permeability (μ), that is, the relative magnetic permeability (μ / μ0), is 5 or more, and further 50 or more.

[0168] Examples of the organic resin constituting the organic resin member include polyamide resins such as PBT (polybutylene terephthalate resin), PPS (polyphenylene sulfide resin), PA66 (nylon 66), PA6 (nylon 6), and PC (polycarbonate resin).

[0169] Furthermore, the above-mentioned organic resin or metal of a member in which at least a part of the joining interface is metal, an organic resin member, or a metal member preferably has a heat resistance temperature of 160 °C or higher.

[0170] [Method for manufacturing the joining member]

[0171] A curable liquid silicone-based adhesive containing a hydroxide compound with a decomposition temperature of 180 to 600 °C and having a content of a material that generates heat by electromagnetic induction of 3% by mass or less is discharged by hand or by machine, coated on the surface of one member in the shape of a joining portion (such as a washer, etc.), the other member is attached and joined, and then cured. Then, it is fixed with bolts or the like as needed.

[0172] When the curable liquid silicone-based adhesive of the present invention is a condensation-curing type liquid silicone-based adhesive, it cures using the moisture in the air at room temperature. Therefore, if multiple components are assembled and left standing, curing will proceed. Humidification is effective when it is desired to increase the curing speed. In addition, when the curable liquid silicone-based adhesive of the present invention is an addition reaction-curing type liquid silicone-based adhesive, it cures by an addition reaction at a temperature of 23 to 150°C. Therefore, after assembling multiple components, if left standing or heated, curing will proceed. When the curable liquid silicone-based adhesive of the present invention is an ultraviolet-curing type liquid silicone-based adhesive, by irradiating ultraviolet rays, the photoinitiator reacts and the curing reaction proceeds to cause curing. Additionally, if necessary, secondary curing can be performed. As the temperature conditions at this time, it is preferably 120°C or higher, more preferably 150°C or higher and less than the decomposition temperature of the hydroxide compound and 250°C or lower. The curing time at this time is preferably 10 minutes to 48 hours, more preferably 30 minutes to 24 hours.

[0173] Examples of the above-mentioned joining members include automotive components such as engines, transmissions, automotive electrical components (ECU (Electronic Control Unit), PCU (Power Control Unit)), etc., electrical and electronic components such as smartphones, tablet computers, liquid crystals, storage batteries, etc., and preferably automotive components and electrical and electronic components.

[0174] The above-mentioned joining members maintain the joined state of the components at an operating ambient temperature of 150°C or lower, preferably room temperature to 120°C.

[0175] The above-mentioned joining members are preferably easily disassemblable joining members that are joined with a certain degree of adhesive force during normal use and whose adhesive force decreases to a level where the components can be separated after electromagnetic induction heating. Specifically, the initial shear adhesive force of the above-mentioned joining members is preferably 1.2 MPa or higher, particularly preferably 1.5 MPa or higher, and the shear adhesive force after electromagnetic induction heating of the joining members is preferably 1 MPa or lower. This shear adhesive force is a value measured according to the method specified in JIS K6850. Furthermore, in order to make the initial and post-electromagnetic induction heating shear adhesive forces within the above ranges, it can be achieved by making the composition of the curable liquid silicone-based adhesive a composition within the above-specified range.

[0176] [Disassembly method]

[0177] Regarding the method for disassembling the joining member of the present invention, the metal part of the joining interface is heated by electromagnetic induction, and the part or all of the cured product (adhesive silicone rubber cured product) obtained by curing a curable liquid silicone-based adhesive as the adhesive member that is in contact with the metal is indirectly heated to 160°C to 800°C. Thus, within the joining member, the metal member naturally peels off, or a force is applied to it by hand, or an instrument such as a spatula is used to peel it off from the metal member, so that the joining member can be disassembled. In addition, the disassembled members can be reused.

[0178] It is presumed that the disassembly of the member according to the present invention becomes possible for the following reasons.

[0179] The difference in the linear expansion coefficients between the metal forming the joining interface and the adhesive member is large. Therefore, if heated, due to the difference in the amount of thermal expansion, a large thermal stress is applied to the joining interface. In addition, in the case of a joining member of dissimilar materials, due to the difference in the amount of thermal expansion, thermal stress is also applied between the joining members. Furthermore, when the metal at the joining interface is heated by electromagnetic induction, the hydroxide compound of component (A) in the cured product (adhesive silicone rubber cured product) obtained by curing a curable liquid silicone-based adhesive as the adhesive member is heated, decomposed to generate water, and the generated water vaporizes and foams, reducing the adhesive force. As a result, the joining member can be disassembled more quickly.

[0180] Regarding electromagnetic induction heating, it is preferable to be able to select the frequency, output power, and time for separating the members. The frequency can be selected within the range of 100 kHz or more and 500 kHz or less, and the output power can be selected within the range of 500 W or more and 5 kW or less. There is no particular limitation on the heating time using electromagnetic induction, and it is 2 minutes or less, preferably 1 minute or less, and more preferably 20 seconds or less.

[0181] Examples

[0182] Next, composition examples, composition comparative examples, examples, and comparative examples are shown to specifically illustrate the present invention, but the present invention is not limited by the following examples. Furthermore, in the following examples, the room temperature is 23°C, the viscosity represents the value at 23°C measured using a rotational viscometer, and the average particle size represents the value obtained as the cumulative weight average D50 (or median diameter) using a particle size distribution measuring device based on the laser diffraction method. The BET specific surface area is the value calculated using the BET equation from the isothermal adsorption curve measured by the nitrogen adsorption method.

[0183] Preparation of curable liquid silicone-based adhesive (composition)

[0184] [Composition Example 1]

[0185] 70 parts by mass of dimethylpolysiloxane with trimethoxysilyl groups at both ends of the molecular chain and a viscosity of 30,000 mPa·s, 40 parts by mass of dimethylpolysiloxane with trimethylsilyl groups at both ends of the molecular chain and a viscosity of 100 mPa·s, 80 parts by mass of aluminum hydroxide with an average particle size of 10 μm and untreated surface (content in the whole composition: 31.0% by mass), BET specific surface area of 17 m 2 / g, 50 parts by mass of colloidal calcium carbonate with a surface treated with fatty acid, 8 parts by mass of vinyltrimethoxysilane, 2 parts by mass of the compound represented by the following formula (1), and 0.8 parts by mass of diisopropoxytitanium bis(ethyl acetoacetate) were uniformly mixed to obtain Composition 1.

[0186] [Chemical Formula 5]

[0187]

[0188] [Composition Example 2]

[0189] 85 parts by mass of dimethylpolysiloxane with hydroxyl groups at both ends of the molecular chain and a viscosity of 20,000 mPa·s, 15 parts by mass of dimethylpolysiloxane with trimethylsilyl groups at both ends of the molecular chain and a viscosity of 100 mPa·s, 70 parts by mass of aluminum hydroxide with an average particle size of 10 μm and untreated surface (content in the whole composition: 31.9% by mass), BET specific surface area of 2.0 m 2 / g, 30 parts by mass of heavy calcium carbonate with a surface treated with paraffin, 9 parts by mass of fumed silica with a BET specific surface area of 120 m 2 / g and a surface treated with dimethyldichlorosilane, 9.2 parts by mass of vinyl tris(1-cyclopentene-1-yloxy)silane, 0.4 parts by mass of γ-(N,N,N',N'-tetramethylguanidino)propyltrimethoxysilane, 0.4 parts by mass of the compound represented by the above formula (1), and 0.4 parts by mass of γ-aminopropyltriethoxysilane were uniformly mixed to obtain Composition 2.

[0190] [Composition Example 3]

[0191] 70 parts by mass of dimethylpolysiloxane with trimethoxysilyl groups at both ends of the molecular chain and a viscosity of 30,000 mPa·s, 40 parts by mass of dimethylpolysiloxane with trimethylsilyl groups at both ends of the molecular chain and a viscosity of 100 mPa·s, 80 parts by mass of aluminum hydroxide with an average particle size of 10 μm and untreated surface (content in the whole composition: 30.8% by mass), BET specific surface area of 17 m 2 / g, 50 parts by mass of colloidal calcium carbonate treated with fatty acid on the surface, 2 parts by mass of iron powder with an average particle size of 30 μm (content in the whole composition: 0.8 mass%), 8 parts by mass of vinyltrimethoxysilane, 2 parts by mass of the compound represented by the above formula (1), and 0.8 parts by mass of diisopropoxytitanium bis(ethyl acetoacetate) were uniformly mixed to obtain Composition 3.

[0192] [Composition Comparative Example 1]

[0193] 70 parts by mass of dimethylpolysiloxane with trimethoxysilyl groups capped at both ends of the molecular chain and a viscosity of 30000 mPa·s, 40 parts by mass of dimethylpolysiloxane with trimethylsilyl groups capped at both ends of the molecular chain and a viscosity of 100 mPa·s, 5 parts by mass of fumed silica, and a BET specific surface area of 17 m 2 / g, 50 parts by mass of colloidal calcium carbonate treated with fatty acid on the surface, 8 parts by mass of vinyltrimethoxysilane, 2 parts by mass of the compound represented by the above formula (1), and 0.8 parts by mass of diisopropoxytitanium bis(ethyl acetoacetate) were uniformly mixed to obtain Composition 4.

[0194] [Composition Comparative Example 2]

[0195] 70 parts by mass of dimethylpolysiloxane with trimethoxysilyl groups capped at both ends of the molecular chain and a viscosity of 30000 mPa·s, 40 parts by mass of dimethylpolysiloxane with trimethylsilyl groups capped at both ends of the molecular chain and a viscosity of 100 mPa·s, 100 parts by mass of aluminum hydroxide with an average particle size of 10 μm and untreated on the surface (content in the whole composition: 30.5 mass%), and a BET specific surface area of 17 m 2 / g, 50 parts by mass of colloidal calcium carbonate treated with fatty acid on the surface, 50 parts by mass of iron powder with an average particle size of 30 μm (content in the whole composition: 15.2 mass%), 8 parts by mass of vinyltrimethoxysilane, 2 parts by mass of the compound represented by the above formula (1), and 0.8 parts by mass of diisopropoxytitanium bis(ethyl acetoacetate) were uniformly mixed to obtain Composition 5.

[0196] [Production of Bonding Member]

[0197] As the base material, a base material made of ADC12 (aluminum alloy die casting) with a width of 25 mm and a length of 50 mm and a base material made of PBT (polybutylene terephthalate resin, heat resistance temperature: 150°C or higher) with a width of 25 mm and a length of 50 mm were used. As the curable liquid silicone-based adhesive, any one of the above Compositions 1 to 5 was used, and the bonding thickness was made 0.5 mm and the bonding area was made 2.5 cm 2The ADC12 base material and the PBT base material were bonded in the following manner, and an aged product was produced by aging for 7 days at 23°C / 50% RH, thereby producing a joined member joined with a cured product (adhesive silicone rubber cured product) of a curable liquid silicone-based adhesive.

[0198] Evaluation of disassemblability

[0199] [Examples 1 to 3, Comparative Examples 1 and 2]

[0200] Using the joined members produced above, evaluation was carried out using the evaluation method shown below. Their results are shown in Table 1, Figure 1 , Figure 2 .

[0201] (1) Initial adhesive force

[0202] Using the joined members produced above, the shear adhesive force was measured according to the method specified in JIS K6850.

[0203] (2) Time until disintegration

[0204] EASYHEAT0224 manufactured by Alonics, Ltd. was used in electromagnetic induction heating. The electromagnetic induction heating was carried out at a frequency of 286 kHz and an output of 2.3 kW, heating the metal part of the joining interface and continuously heating until the joined member disintegrated. The time at the time of disintegration was measured with a stopwatch, and less than 15 seconds was considered qualified, and more than 15 seconds was considered unqualified. For all the compositions, the joined members disintegrated only by heating.

[0205] (3) State of the disintegrated joining surface of electromagnetic induction heating

[0206] The state of the joining surface of the disintegrated ADC12 base material was observed with a digital microscope VHX8000 manufactured by KEYENCE Corporation. The state before electromagnetic induction heating in Example 1 is shown in Figure 1 , and the state after electromagnetic induction heating is shown in Figure 2 . In addition, on the PBT base material side, the remaining adhesive was cut with a cutter, and the surface state was visually confirmed. The case where there was no change in the surface state of the ADC12 base material and the PBT base material before and after electromagnetic induction heating was recorded as no change.

[0207] (4) Adhesive force after reuse

[0208] The reusability of components disassembled by electromagnetic induction heating was confirmed. The ADC12 substrate was used directly. For the PBT substrate side, after cutting the adhesive with a cutter, the adhesive was completely removed with a silicone decomposing agent (silicone cleaner X-100), and then used after washing with water and drying. The joining components were fabricated using the same method as described above. The shear adhesive strength was measured according to the method specified in JIS K6850.

[0209] [Table 1]

[0210]

[0211] From the above results, it can be seen that Examples 1 to 3 of the disassembly method of the joining component of the present invention can be easily disassembled by electromagnetic induction heating in a short time of 12 to 14 seconds with less energy consumption, and can be reused.

[0212] On the other hand, although disassembly was possible in Comparative Example 1, since no hydroxide compound was added, the effect of reducing the adhesive strength due to foaming was not obtained, and the time until disassembly was extended, but it could be reused. In Comparative Example 2, since 15.2 mass% of metal powder was also added to the composition, the adhesive was also heated and the PBT substrate was dissolved, and it could not be reused.

Claims

1. A method for disassembling a joined member, comprising the steps of: for a joined member formed by joining a plurality of members, at least a part of the joint interface of which is a metal member, heating the metal part of the joint interface by electromagnetic induction to separate the member containing the metal in these members and disassemble the joined member, wherein the curable liquid silicone-based adhesive contains 25 to 80% by mass of a hydroxide compound having a decomposition temperature of 180 to 600 °C and the content of the material that generates heat by electromagnetic induction is 3% by mass or less.

2. The method for disassembling a joined member according to claim 1, wherein, The curable liquid silicone-based adhesive is a condensation-curing liquid silicone-based adhesive, an addition-reaction-curing liquid silicone-based adhesive, or an ultraviolet-curing liquid silicone-based adhesive.

3. The method for disassembling a joined member according to claim 1, wherein, The hydroxide compound having a decomposition temperature of 180 to 600°C is at least one selected from aluminum hydroxide, magnesium hydroxide, and aluminum oxyhydroxide (boehmite).

4. The method for disassembling a joined member according to claim 1, wherein, The frequency of electromagnetic induction heating is 100 kHz or more and 500 kHz or less.

5. The method for disassembling a joined member according to claim 1, wherein, The joining member is an automotive part or an electric and electronic part.

6. A condensable curable liquid silicone-based adhesive with easy disassembly property, which contains the following components (A) to (E) for the method for disassembling a joined member according to any one of claims 1 to 5, and the content of the material that generates heat by electromagnetic induction is 3% by mass or less. (A) A hydroxide compound having a decomposition temperature of 180 to 600 °C: its amount is 25 to 80% by mass of the whole adhesive. (B) A linear diorganopolysiloxane having its molecular chain ends capped with hydroxyl groups and / or hydrolyzable silyl groups bonded to silicon atoms: 100 parts by mass. (C) A hydrolyzable organosilane compound having three or more hydrolyzable groups bonded to silicon atoms in the molecule and / or its partial hydrolysis condensate: 0.1 to 40 parts by mass. (D) A curing catalyst: 0.001 to 20 parts by mass, and (E) A silane coupling agent: 0.05 to 20 parts by mass.

7. An addition reaction curable liquid silicone-based adhesive with easy disassembly property, which contains the following components (A) and (F) to (H) for the method for disassembling a joined member according to any one of claims 1 to 5, and the content of the material that generates heat by electromagnetic induction is 3% by mass or less. (A) A hydroxide compound having a decomposition temperature of 180 to 600 °C: its amount is 25 to 80% by mass of the whole adhesive. (F) An alkenyl-containing organopolysiloxane having an alkenyl group bonded to a silicon atom at the molecular chain end: 100 parts by mass. (G) An organohydrogenpolysiloxane having at least two hydrogen atoms bonded to silicon atoms in the molecule: in an amount such that, relative to 1 mole of the alkenyl group bonded to silicon atoms in the component (F), the hydrogen atoms bonded to silicon atoms are 0.01 to 3 moles, (H) A platinum group metal catalyst: 0.01 to 1000 ppm in terms of the mass of platinum group metal atoms, relative to the total amount of the components (F) and (G), and (I) An adhesion promoter: 0.05 to 20 parts by mass.

8. A readily disassemblable ultraviolet-curable liquid silicone-based adhesive, which contains the following components (A) and (J), (K) for the disassembly method of the joining member according to any one of claims 1 to 5, and the content of the material that generates heat by electromagnetic induction is 3% by mass or less, (A) A hydroxide compound having a decomposition temperature of 180 to 600 °C: in an amount that becomes 25 to 80% by mass of the whole adhesive, (J) An ultraviolet-reactive organopolysiloxane: 100 parts by mass, and (K) A photoinitiator: 0.01 to 10 parts by mass.

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