Method for disassembling joint members and easily disassemblable liquid silicone adhesive

Abstract

In the present invention, a bonded member is obtained by bonding together a plurality of members, including a member in which at least a portion of a bonding interface is metal, by means of a cured product obtained by curing a curable silicone-based liquid adhesive agent, which contains 25-80 mass% of a hydroxide compound having a decomposition temperature of 180-600ºC and in which the content of a material for generating heat by electromagnetic induction is no more than 3 mass%. The bonded member exhibits sealing properties at room temperature and, moreover, it is possible to easily disassemble the bonded member in a short time and with little consumed energy, even after exposure to high temperatures of approximately 150ºC, by heating the metal portion at the bonding interface of the bonded member by electromagnetic induction, and it is possible to recycle the disassembled member.

Description

[Technical Field]

[0001] The present invention relates to a method for disassembling a jointed member using a curable liquid silicone adhesive that enables quick and easy collection, repair, and recycling of automotive parts such as automotive electrical components, and electrical and electronic products, and to an easily disassemblable liquid silicone adhesive used in the said method. [Background technology]

[0002] In recent years, recyclability has been increasingly demanded in various fields due to its environmental friendliness and cost-saving benefits. In fields such as automotive and electrical / electronics, disassembly of connecting components is necessary for recycling. On the other hand, connecting components play a crucial role in preventing the intrusion of external dust and moisture and protecting internal parts, thus requiring reliable sealing performance. Adhesion provides the best sealing performance, and therefore, maintaining adhesion under various conditions (heat resistance, humidity resistance, etc.) is essential. Consequently, the cured material is usually strongly bonded to the substrate, making removal of connecting components difficult.

[0003] As a method for recycling bonding members using curable resin compositions, for example, Japanese Patent Publication No. 2003-026784 (Patent Document 1) proposes softening or liquefying bonding members made using a polyol-based curable composition by heating them to 150-200°C, thereby separating the members joined by the cured material. Also, Japanese Patent Publication No. 2002-327163 (Patent Document 2) proposes reducing the adhesive strength of a bonded structure by contacting the bonded portion with a halogen-based organic solvent, thereby separating the constituent members of the bonded structure from the bonded portion. Furthermore, Japanese Patent Publication No. 2008-120903 (Patent Document 3) proposes a re-peelable adhesive tape that uses an adhesive made of a vinyl monomer mixture mainly composed of alkyl (meth)acrylate, maintaining high normal adhesive strength during bonding, while reducing adhesive strength by heating when separating and disassembling the bonded portion, allowing for easy separation and disassembly. Furthermore, Japanese Patent Publication No. 6221630 (Patent Document 4) proposes that by incorporating a tackifying resin into the oxyalkylene polymer, it is possible to rework the polymer, recombine it after rework, and maintain its sealing performance.

[0004] On the other hand, silicone-based adhesives and sealants have superior properties such as heat resistance and weather resistance compared to the organic adhesives mentioned above, and are therefore widely used in the automotive, electrical and electronic, and construction sectors. However, a drawback is that silicone-based adhesives and sealants are difficult to decompose even when heated, making them difficult to repair or recycle.

[0005] Masking-type silicone adhesives have been proposed as silicone adhesives that allow for easy disassembly of components while still providing sealing properties. While some masking-type silicone adhesives do not contain adhesion promoters, others have release agents added to provide release properties to glass and metal. However, in high-temperature endurance exceeding 200°C, the release agent itself decomposes and loses its effectiveness. This causes the components and the silicone adhesive to bond due to heat, making disassembly difficult and hindering recovery and repair.

[0006] Therefore, even in applications where silicone-based adhesives are used for bonding, there is a need for recyclable bonding components and methods for dismantling them. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2003-026784 [Patent Document 2] Japanese Patent Publication No. 2002-327163 [Patent Document 3] Japanese Patent Publication No. 2008-120903 [Patent Document 4] Patent No. 6221630 [Patent Document 5] Japanese Patent Publication No. 2022-183437 [Patent Document 6] Patent application No. 2021-160447 [Overview of the project] [Problems that the invention aims to solve]

[0008] The present invention has been made in view of the above circumstances, and aims to provide a method for dismantling a bonded adhesive member, in which the bonded adhesive member is a silicone-based adhesive, and which can be easily recycled in a short time and with little energy consumption while maintaining its sealing performance even after being exposed to high temperatures of about 150°C at room temperature (23°C ± 15°C, the same applies hereinafter), and an easily dismantled liquid silicone-based adhesive used in the method for dismantling the bonded member. [Means for solving the problem]

[0009] To achieve the above objective, the present inventors previously filed Japanese Patent Application Publication No. 2022-183437 (Japanese Patent Application No. 2021-090750) (Patent Document 5) proposed a method in which aluminum hydroxide, which decomposes from around 160°C, is blended in a specific proportion into a curable liquid silicone adhesive. This method allows the bonded adhesive members to maintain their sealing properties even after being exposed to room temperature and even to high temperatures of around 150°C, while reducing their sealing properties when exposed to temperatures above 160°C, thereby facilitating the separation of the members. However, this method requires heating for several hours using a heating furnace, resulting in high energy consumption.

[0010] Furthermore, in Japanese Patent Application No. 2021-160447 (Patent Document 6), a method was proposed for easily disassembling multiple components by irradiating a jointed component, which is joined together with a curable liquid silicone adhesive containing microwave-heat-generating particles and a hydroxide compound with a decomposition temperature of 180-600°C, with microwaves. However, this method still takes several minutes, and a method for disassembly in an even shorter time is desired.

[0011] Therefore, the inventors diligently studied a jointing member and a dismantling method that consumes less energy and can be recycled in a shorter time. As a result, in order to improve the efficiency and energy saving of collection, repair, and recycling operations for automobile parts, electrical and electronic products, the inventors have found that a curable liquid silicone adhesive containing 25 to 80% by mass of a hydroxide compound (particularly metal hydroxide or metal oxide hydroxide) with a decomposition temperature of 180 to 600°C, and containing 3% by mass or less of a material that generates heat by electromagnetic induction, can be used to curate a jointing member in which multiple members are joined together, including a member in which at least a part of the joint interface is metal, exhibits sealing properties even after being exposed to room temperature and even to high temperatures of about 150°C. Furthermore, by heating the metal portion of the joint interface of the jointing member by electromagnetic induction, the jointing member can be easily dismantled in a short time with little energy consumption, and the dismantled members can be recycled. Thus, the inventors have completed the present invention.

[0012] Accordingly, the present invention provides a method for disassembling the following joint members and an easily disassemblable liquid silicone adhesive. [1] A cured product obtained by curing a curable liquid silicone-based adhesive containing 25 to 80% by mass of a hydroxide compound having a decomposition temperature of 180 to 600°C and containing 3% by mass or less of a material that generates heat by electromagnetic induction, for a joined member in which a plurality of members including a member having at least a part of a joining interface made of metal are joined together, a method for disassembling the joined member, comprising a step of separating the member containing the metal from among the members by heating the metal part of the joining interface by electromagnetic induction to disassemble the joined member. [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. [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 oxide (boehmite). [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. [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 electric / electronic part. [6] A readily disassemblable condensation-curing type liquid silicone-based adhesive containing the following components (A) to (E) used in the method for disassembling a joined member according to any one of [1] to [5] and containing 3% by mass or less of a material that generates heat by electromagnetic induction. (A) Hydroxide compound having a decomposition temperature of 180 to 600°C: an amount to be 25 to 80% by mass of the whole adhesive, (B) Linear diorganopolysiloxane having both ends of the molecular chain blocked with a hydroxyl group and / or a hydrolyzable silyl group bonded to a silicon atom: 100 parts by mass, (C) Hydrolyzable organosilane compound having three or more hydrolyzable groups bonded to a silicon atom in the molecule and / or a partial hydrolysis condensate thereof: 0.1 to 40 parts by mass, (D) Hardening catalyst: 0.001 to 20 parts by mass, and (E) Silane coupling agent: 0.05 to 20 parts by mass. [7] [1] to [5] Any of the described disassembly methods of the joining member is used for the following (A) and (F) ~ (I) A component-containing, easily disassembled addition reaction-curing type liquid silicone adhesive in which the content of the material that generates heat by electromagnetic induction is 3% by mass or less. (A) Hydroxide compound having a decomposition temperature of 180 to 600 ° C: an amount that becomes 25 to 80% by mass of the entire adhesive, (F) Alkenyl group-containing organopolysiloxane having an alkenyl group bonded to a silicon atom at the molecular chain end: 100 parts by mass, (G) Organohydrogenpolysiloxane having at least two hydrogen atoms bonded to silicon atoms in the molecule: an amount such that the silicon atom-bonded hydrogen atom is 0.01 to 3 moles with respect to 1 mole of the alkenyl group bonded to the silicon atom in the (F) component, (H) Platinum group metal catalyst: 0.01 to 1,000 ppm in terms of the mass of platinum group metal atoms with respect to the total amount of the (F) component and the (G) component, and (I) Adhesion-imparting agent: 0.05 to 20 parts by mass. [8] [1] to [5] Any of the described disassembly methods of the joining member is used for the following (A) and (J), (K) components, and an easily disassembled ultraviolet-curing type liquid silicone adhesive in which the content of the material that generates heat by electromagnetic induction is 3% by mass or less. (A) Hydroxide compound having a decomposition temperature of 180 to 600 ° C: an amount that becomes 25 to 80% by mass of the entire adhesive, (J) Ultraviolet-reactive organopolysiloxane: 100 parts by mass, and (K) Photoinitiator: 0.01 to 10 parts by mass.

Effect of the Invention

[0013] According to the present invention's method for dismantling a jointed member, while maintaining adhesive and / or sealing properties from room temperature up to a high temperature of approximately 150°C, the curable liquid silicone adhesive, which is the adhesive member, is indirectly heated by heating the metal portion of the joint interface using electromagnetic induction heating, thereby reducing its adhesive and / or sealing properties. As a result, the metal-containing member at the joint interface can be peeled off in a short time and with little energy, allowing the jointed member to be easily dismantled and recycled. The curable liquid silicone adhesive used in this dismantling method is useful as an adhesive or sealant for joints that require heat resistance and recycling.

[0014] In this invention, the "heat resistance temperature" of the component to be dismantled means the upper limit of the temperature at which the component does not undergo thermal decomposition or softening when left undisturbed at a specific temperature for one minute. [Brief explanation of the drawing]

[0015] [Figure 1] This image shows the surface state of the ADC12 substrate before electromagnetic induction heating in Example 1 of the present invention, as observed with a digital microscope. [Figure 2] This image shows the surface condition of the ADC12 substrate after electromagnetic induction heating in Example 1 of the present invention, as observed with a digital microscope. [Modes for carrying out the invention]

[0016] The present invention will be described in detail below.

[0017] The present invention provides a method for dismantling a jointed member, which is a jointed member in which multiple members are joined together, including a member whose joining interface is metal, and the cured product is made by curing a curable liquid silicone adhesive having a decomposition temperature of 180 to 600°C and containing 25 to 80% by mass of a hydroxide compound (particularly metal hydroxide or metal oxide hydroxide) and a content of a material that generates heat by electromagnetic induction of 3% by mass or less, and the member in which at least a part of the joining interface is metal, and the method provides a step of dismantling the jointed member by heating the metal portion of the joining interface by electromagnetic induction to separate the member containing the metal from among the members.

[0018] [Curing liquid silicone adhesive] The curable liquid silicone adhesive used in the present invention is an adhesive member that hardens to join multiple members, including a member whose bonding interface has at least a portion made of metal. It contains a hydroxide compound (A) with a decomposition temperature of 180 to 600°C, contains 3% by mass or less of a material that generates heat by electromagnetic induction, and uses a polymer as the base polymer whose main chain consists of siloxane bonds. The curing type is preferably condensation curing, addition reaction curing, or ultraviolet curing.

[0019] [Hydroxide compounds with a decomposition temperature of 180-600°C] Hydroxide compounds with a decomposition temperature of 180-600°C are usually preferably metal hydroxides or metal oxide hydroxides, and examples include aluminum hydroxide with a decomposition temperature of around 180°C, magnesium hydroxide with a decomposition temperature of around 300°C, and aluminum hydroxide oxide (boehmite) with a decomposition temperature of around 500°C. The "decomposition temperature" refers to the temperature at which the hydroxide compound begins to decompose and produce water.

[0020] These materials begin to decompose when heated, and this decomposition generates water, which has an anti-flammability effect and has traditionally been used in flame-retardant materials. In this invention, the water generated by this decomposition is used to reduce the adhesive strength by creating bubbles in the cured product of a curable liquid silicone adhesive, thereby making it possible to quickly and easily disassemble the joined members.

[0021] For hydroxide compounds with a decomposition temperature of 180-600°C, particulate matter with an average particle size of 50 μm or less, preferably 0.5-20 μm, is used. If the average particle size is greater than 50 μm, the decomposition rate decreases. The average particle size can be determined as the cumulative weight average D50 (or median diameter) using a particle size distribution analyzer such as a laser diffraction method.

[0022] The surface of the hydroxide compound may be untreated or surface-treated (hydrophobic). When surface treatment is performed, commonly used treatment agents include silane coupling agents and fatty acids. Surface treatment can be carried out by known methods. There are no particular restrictions on the amount of treatment, but it is preferably 3% by mass or less (usually 0.1 to 3% by mass), and particularly preferably 0.2 to 2% by mass.

[0023] While a single hydroxide compound may be used alone, two or more compounds with different average particle sizes or surface treatment methods can also be used in combination.

[0024] The hydroxide compound content is 25 to 80% by mass of the total curable liquid silicone adhesive, preferably 30 to 70% by mass, and more preferably 35 to 65% by mass. If the content is less than 25% by mass, the decomposition (foaming) of the hydroxide compound is insufficient and the decompositionability decreases, and if the amount exceeds 80% by mass, the viscosity of the composition increases and the dispensability during mixing and application deteriorates.

[0025] [Materials that generate heat through electromagnetic induction] Examples of materials that generate heat through electromagnetic induction include metal materials, carbon fibers, and carbon materials such as carbon black. Examples of metal materials used in curable liquid silicone adhesives include aluminum powder, iron powder, copper powder, and their alloy powders.

[0026] The curable liquid silicone adhesive used in this invention contains as few as possible materials that generate heat through electromagnetic induction. However, even if a material that generates heat through electromagnetic induction is included as an additive such as a colorant, the amount of such material should be 3% by mass or less (0-3% by mass), and especially 1% by mass or less (0-1% by mass), in the curable liquid silicone adhesive. If it exceeds 3% by mass, the disassembly properties will decrease.

[0027] The electromagnetic induction heating used in the present invention can heat conductive metal materials and carbon materials (e.g., carbon fiber, graphite, carbon black, etc.). On the other hand, in the present invention, by heating the bonding interface portion of the metal used in the bonding member by electromagnetic induction, delamination can be efficiently caused 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 to heat the bonded member (cured adhesive), which reduces the ability to disassemble. Furthermore, when an organic resin is used in the member, the heating of the bonded member causes the organic resin in contact with the bonded member to heat up to the point where it exceeds its heat resistance, causing the organic resin to dissolve or decompose, making the member unsuitable for recycling. For this reason, it is preferable to add as little as possible (3% by mass or less) a material that generates heat by electromagnetic induction to the curable liquid silicone adhesive of the present invention.

[0028] [Condensation-curing liquid silicone adhesive] The condensation-curing liquid silicone adhesive is a liquid silicone adhesive that, in addition to the above-mentioned (A) hydroxide compound with a decomposition temperature of 180 to 600°C, contains (B) a linear diorganopolysiloxane (base polymer) in which both ends of the molecular chain are sealed with hydroxyl groups and / or hydrolyzable silyl groups bonded to silicon atoms, (C) a hydrolyzable organosilane compound and / or a partially hydrolyzed condensate thereof (crosslinking agent) having three or more hydrolyzable groups bonded to silicon atoms in the molecule, (D) a curing catalyst, and (E) a silane coupling agent (adhesion imparting agent), and obtains a cured product by utilizing a hydrolysis-condensation reaction by moisture (humidity) in the atmosphere at room temperature. As for condensation-curing liquid silicone adhesives, (A) Hydroxide compounds with a decomposition temperature of 180-600°C: in an amount that is 25-80% by mass of the total adhesive. (B) A linear diorganopolysiloxane in which both ends of the molecular chain are sealed with hydroxyl groups and / or hydrolyzable silyl groups bonded to silicon atoms: 100 parts by mass, (C) Hydrolyzable organosilane compounds and / or partially hydrolyzed condensates thereof having three or more hydrolyzable groups bonded to silicon atoms in the molecule: 0.1 to 40 parts by mass, (D) Curing catalyst: 0.001 to 20 parts by mass, and (E) Silane coupling agent: 0.05 to 20 parts by mass A readily disassembled, condensation-curing liquid silicone adhesive is preferred, which contains a material that generates heat by electromagnetic induction and has a content of 3% by mass or less of such material.

[0029] (B) The organopolysiloxane as the base polymer (main component) is a linear diorganopolysiloxane in which both ends of the molecular chain are sealed with hydroxyl groups (silanol groups) and / or hydrolyzable silyl groups bonded to silicon atoms. Here, alkoxysilyl groups or alkoxy-substituted alkoxysilyl groups are preferred as the hydrolyzable silyl groups.

[0030] If the molecule has a hydroxyl group (silanol group) bonded to a silicon atom, it is preferable to have one hydroxyl group (i.e., a hydroxysilyl group or silanol group) bonded to a silicon atom at each end of the molecular chain.

[0031] When a hydrolyzable silyl group has an alkoxysilyl group or an alkoxy-substituted alkoxysilyl group at its terminus, it is preferable that both ends of the molecular chain have two or three alkoxy groups (i.e., alkoxysilyl groups) bonded to a silicon atom or alkoxy-substituted alkoxy groups (i.e., alkoxyalkoxysilyl groups) bonded to a silicon atom (i.e., these exist as dialkoxyorganosilyl groups or bis(alkoxyalkoxy)organosilyl groups, or trialkoxysilyl groups or tris(alkoxyalkoxy)silyl groups).

[0032] As for the alkoxy group, alkoxy groups having 1 to 10 carbon atoms, particularly 1 to 4 carbon atoms, are preferred. Examples include methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, tert-butoxy, hexyloxy, and octyloxy groups.

[0033] Preferred alkoxy-substituted alkoxy groups include those having 2 to 10 carbon atoms, particularly 2 to 4 carbon atoms, such as methoxyethoxy groups, ethoxyethoxy groups, and methoxypropoxy groups.

[0034] As a linear diorganopolysiloxane in which both ends of the molecular chain are sealed with hydroxyl groups and / or hydrolyzable silyl groups bonded to silicon atoms, it is particularly preferable that the diorganopolysiloxane has hydroxyl groups (silanol groups), methoxy groups, or ethoxy groups at both ends, preferably only at both ends.

[0035] Organic groups bonded to silicon atoms other than hydroxyl groups and hydrolyzable groups include unsubstituted or substituted monovalent hydrocarbon groups having 1 to 18 carbon atoms, preferably 1 to 10 carbon atoms. Examples of such monovalent hydrocarbon groups include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, hexyl, heptyl, octyl, and 2-ethylhexyl groups; cycloalkyl groups such as cyclopentyl and cyclohexyl groups; alkenyl groups such as vinyl and allyl groups; aryl groups such as phenyl, tolyl, and naphthyl groups; aralkyl groups such as benzyl, phenylethyl, and phenylpropyl groups; and halogenated monovalent hydrocarbon groups such as trifluoropropyl and chloropropyl groups, in which some or all of the hydrogen atoms bonded to the carbon atoms of these groups are substituted with halogen atoms such as fluorine, bromine, and chlorine, or cyano groups; and cyanoalkyl groups such as β-cyanoethyl and γ-cyanopropyl groups. Among these, the methyl group is preferred.

[0036] The viscosity of the organopolysiloxane used as the base polymer (main component) at 23°C is preferably 50 to 1,000,000 mPa·s, and more preferably 100 to 300,000 mPa·s. If the viscosity is below the lower limit, the resulting cured product may not have sufficient mechanical properties, and if it exceeds the upper limit, the workability may decrease. In this invention, viscosity is the value measured at 23°C using a rotational viscometer (e.g., BL type, BH type, BS type, cone plate type, rheometer, etc.) (the same applies hereinafter).

[0037] The organopolysiloxane used as the base polymer (main component) may be used alone or in combination of two or more types.

[0038] (C) The hydrolyzable organosilane compound and / or its partially hydrolyzed condensate as a crosslinking agent (curing agent) is a hydrolyzable organosilane compound and / or its partially hydrolyzed condensate (i.e., a siloxane compound such as a siloxane oligomer having three or more residual hydrolyzable groups in the molecule) having three or more hydrolyzable groups bonded to silicon atoms in the molecule. Component (C) acts as a crosslinking agent (curing agent) that forms a crosslinked structure by hydrolysis and condensation reactions with a linear diorganopolysiloxane in which both ends of the molecular chain are sealed with hydroxyl groups and / or hydrolyzable silyl groups bonded to silicon atoms, which are the base polymer.

[0039] Hydrolyzable groups in hydrolyzable organosilane compounds include alkoxy groups, alkoxy-substituted alkoxy groups, acyloxy groups, alkenoxy groups, ketoxime groups, aminooxy groups, and amide groups, each having 1 to 10 carbon atoms. Examples include alkoxy groups such as methoxy, ethoxy, and propoxy groups; alkoxy-substituted alkoxy groups such as methoxyethoxy, ethoxyethoxy, and methoxypropoxy groups; acyloxy groups such as acetoxy and octanoyloxy groups; alkenoxy groups such as vinyloxy, isopropenoxy, and 1-ethyl-2-methylvinyloxy groups; ketoxime groups such as dimethylketoxime, methylethylketoxime, and methylisobutylketoxime groups; aminooxy groups such as dimethylaminooxy and diethylaminooxy groups; and amide groups such as N-methylacetamide and N-ethylacetamide groups.

[0040] Hydrolyzable organosilane compounds may have organic groups bonded to silicon atoms other than the hydrolyzable groups described above. Examples of such organic groups bonded to silicon atoms other than the hydrolyzable groups include unsubstituted or substituted monovalent hydrocarbon groups having 1 to 18 carbon atoms, preferably 1 to 10 carbon atoms. Examples include 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 halogenated alkyl groups in which some or all of the hydrogen atoms bonded to the carbon atoms of these groups are substituted with halogen atoms such as fluorine, bromine, or chlorine, or with cyano groups, such as 3-chloropropyl and 3,3,3-trifluoropropyl. Among these, methyl, ethyl, propyl, vinyl, and phenyl groups are preferred as unsubstituted or substituted monovalent hydrocarbon groups.

[0041] Examples of hydrolyzable organosilane compounds and their partial hydrolysis condensates include alkoxysilanes such as methyltrimethoxysilane, ethyltrimethoxysilane, decyltrimethoxysilane, vinyltrimethoxysilane, phenyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, vinyltriethoxysilane, phenyltriethoxysilane, vinyltris(1-cyclopenten-1-yloxy)silane, tetramethoxysilane, and tetraethoxysilane; ketoxime silanes such as methyltris(dimethylketoxime)silane, methyltris(methylethylketoxime)silane, ethyltris(methylethylketoxime)silane, methyltris(methylisobutylketoxime)silane, and vinyltris(methylethylketoxime)silane; and methyltri(methoxymethoxy)silane, ethyltri(methoxymethoxy)silane, and vinyltri(methoxymethoxy)silane. Examples include alkoxy-substituted alkoxysilanes such as phenyltri(methoxymethoxy)silane, methyltri(ethoxymethoxy)silane, ethyltri(ethoxymethoxy)silane, vinyltri(ethoxymethoxy)silane, phenyltri(ethoxymethoxy)silane, tetra(methoxymethoxy)silane, and tetra(ethoxymethoxy)silane; aminooxysilanes such as methyltris(N,N-diethylaminooxy)silane; amidesilanes such as methyltris(N-methylacetamide)silane, methyltris(N-butylacetamide)silane, and methyltris(N-cyclohexylacetamide)silane; alkenoxysilanes such as methyltriisopropenoxysilane, vinyltriisopropenoxysilane, and phenyltriisopropenoxysilane; asilooxysilanes such as methyltriacetoxysilane and vinyltriacetoxysilane; and partial hydrolysis condensates of these hydrolyzable organosilane compounds.

[0042] Hydrolyzable organosilane compounds used as crosslinking agents (curing agents) are clearly distinguishable from (E) silane coupling agents used as adhesion promoters, as described later, in that they do not contain monovalent hydrocarbon groups in their molecules that are substituted with functional groups having heteroatoms such as nitrogen atoms, oxygen atoms, or sulfur atoms.

[0043] Hydrolyzable organosilane compounds and / or their partially hydrolyzed condensates may be used individually or in combination of two or more.

[0044] The amount of hydrolyzable organosilane compound and / or its partially hydrolyzed condensate used as a crosslinking agent (curing agent) is 0.1 to 40 parts by mass, preferably 1 to 20 parts by mass, per 100 parts by mass of linear diorganopolysiloxane in which both ends of the molecular chain are sealed with hydroxyl groups and / or hydrolyzable silyl groups bonded to silicon atoms. If the amount of hydrolyzable organosilane compound and / or its partially hydrolyzed condensate is less than the lower limit (0.1 parts by mass), it may lead to a decrease in curability and shelf life. If it exceeds the upper limit (40 parts by mass), it may not only be disadvantageous in terms of price, but may also lead to a decrease in the elongation of the resulting cured product and a decrease in durability.

[0045] (D) The curing catalyst can be a condensation catalyst that has been commonly used as a curing accelerator for condensation-curing liquid silicone adhesives (room-temperature curable organopolysiloxane compositions). Examples include organotin compounds such as dibutyltin methoxide, dibutyltin diacetate, dibutyltin dioctate, dibutyltin dilaurate, dioctyltin dilaurate, dioctyltin dioctate, dioctyltin dineodecanoate, dimethyltin dimethoxide, and dimethyltin diacetate; organotin compounds such as tetrapropyl titanate, tetrabutyl titanate, tetra-2-ethylhexyl titanate, diisopropoxytitanium bis(ethylacetoacetate), and dimethoxytitanium diacetylacetonate; and amine compounds such as hexylamine and tetramethylguanidylpropyltrimethoxysilane, or salts thereof. One of these can be used alone or in combination of two or more.

[0046] The amount of curing catalyst added 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, per 100 parts by mass of linear diorganopolysiloxane in which both ends of the molecular chain are sealed with hydroxyl groups and / or hydrolyzable silyl groups bonded to silicon atoms. If the amount of curing catalyst added is less than the lower limit (0.001 parts by mass), the catalytic effect may not be obtained. If the amount of curing catalyst added exceeds the upper limit (20 parts by mass), it will not only be disadvantageous in terms of price, but the durability of the composition may decrease, or the adhesiveness may decrease.

[0047] The condensation-curing liquid silicone adhesive is further enriched with a silane coupling agent as component (E), which improves adhesive strength and acts as an adhesion-enhancing component. This silane coupling agent is a hydrolyzable silane compound having a monovalent hydrocarbon group in its molecule substituted with a functional group containing heteroatoms such as nitrogen, oxygen, or sulfur atoms (excluding guanidyl groups), a so-called carbon functional silane compound.

[0048] As the silane coupling agent used as the adhesion-imparting component, silane coupling agents known in the art are preferably used. In particular, those having an alkoxy group or an alkenoxy group as a hydrolyzable group are preferred. Specifically, examples include alkoxy groups such as methoxy, ethoxy, and propoxy groups, and alkenoxy groups such as vinyloxy, isopropenoxy, and 1-ethyl-2-methylvinyloxy groups.

[0049] Furthermore, as monovalent hydrocarbon groups substituted with functional groups having heteroatoms such as nitrogen atoms, oxygen atoms, and sulfur atoms (excluding guanidyl groups), it is preferable to have monovalent hydrocarbon groups with 1 to 20 carbon atoms having at least one unsubstituted or substituted amino group, unsubstituted or substituted imino group, mercapto group, epoxy group, (meth)acryloxy group, etc. Specifically, γ-acryloxypropyl group, γ-methacryloxypropyl group, β-(3,4-epoxycyclohexyl)ethyl group, γ-glycidoxypropyl group, N-β(aminoethyl)γ-aminopropyl group, γ-aminopropyl group, and the following formula [ka] Examples of groups include the γ-mercaptopropyl group.

[0050] The silane coupling agent may have organic groups that bond to silicon atoms other than monovalent hydrocarbon groups substituted with the above-mentioned hydrolyzable and functional groups. Preferred organic groups that bond to silicon atoms other than monovalent hydrocarbon groups substituted with hydrolyzable and functional groups are monovalent hydrocarbon groups having 1 to 10 carbon atoms. Examples include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, hexyl, heptyl, and octyl groups; cycloalkyl groups such as cyclopentyl and cyclohexyl groups; alkenyl groups such as vinyl and allyl groups; aryl groups such as phenyl, tolyl, and xylyl groups; and aralkyl groups such as benzyl and phenethyl groups. Among these, methyl and ethyl groups are preferred.

[0051] Specifically, silane coupling agents include γ-acryloxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, N-β(aminoethyl)γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, and the following formula [ka] Examples of silane compounds include those shown, such as γ-mercaptopropyltrimethoxysilane, γ-glycidoxypropyltriisopropenoxysilane, and γ-glycidoxypropylmethyldiisopropenoxysilane. In particular, the use of an amino group-containing silane coupling agent is preferred.

[0052] Silane coupling agents may be used individually or in combination of two or more types.

[0053] The amount of silane coupling agent component (E) 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, per 100 parts by mass of linear diorganopolysiloxane in which both ends of the molecular chain are sealed with hydroxyl groups and / or hydrolyzable silyl groups bonded to silicon atoms. If the amount is less than 0.05 parts by mass, sufficient adhesion cannot be obtained, and if it exceeds 20 parts by mass, the resulting cured product will have poor weather resistance and mechanical properties.

[0054] In addition to the components mentioned above, optional components may be added to the condensation-curing liquid silicone adhesive, provided that they do not impair the objectives of the present invention. Examples of these optional components include inorganic fillers other than component (A), pigments, dyes, colorants such as fluorescent whitening agents; antibacterial agents; antifungal agents; and plasticizers such as silicone oil (non-functional organopolysiloxane).

[0055] Examples of inorganic fillers other than the optional component (A) include carbon such as acetylene black, dry silica (such as fuzzy silica), wet silica (such as precipitated silica), quartz powder, diatomaceous earth powder, particulate alumina, magnesia powder, colloidal calcium carbonate, heavy calcium carbonate, and finely powdered inorganic fillers obtained by surface-treating these with silanes, silazanes, low-polymerization polysiloxanes, etc. (excluding component (A)). When inorganic fillers other than component (A) are included, the amount is preferably 0.1 to 800 parts by mass, and more preferably 0.5 to 600 parts by mass, per 100 parts by mass of linear diorganopolysiloxane in which both ends of the molecular chain are sealed with hydroxyl groups and / or hydrolyzable silyl groups bonded to silicon atoms.

[0056] Condensation-curing liquid silicone adhesives can be prepared by uniformly mixing the above-mentioned components using a known mixer in a moisture-free environment (in a dry atmosphere or under reduced pressure) in accordance with conventional methods.

[0057] Furthermore, the resulting condensation-curing liquid silicone adhesive hardens by being left at room temperature (23°C ± 15°C), but the molding method and hardening conditions can be those of known types of condensation-curing liquid silicone adhesives. For example, it can be hardened by being left in the air for several hours to several days (e.g., 6 hours to 7 days) under conditions of 23°C / 50%RH.

[0058] [Addition reaction curing type liquid silicone adhesive] The addition-curing liquid silicone adhesive is a liquid silicone adhesive that, in addition to the above-mentioned (A) hydroxide compound with a decomposition temperature of 180 to 600°C, comprises (F) an alkenyl group-containing organopolysiloxane (base polymer) having alkenyl groups such as vinyl groups bonded to silicon atoms at the end of the molecular chain, (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 imparter, and obtains a cured product by crosslinking through the addition reaction of SiH groups to vinyl groups (hydrosilylation reaction). As for addition-curing liquid silicone adhesives, (A) Hydroxide compounds with a decomposition temperature of 180-600°C: in an amount that is 25-80% by mass of the total adhesive. (F) Alkenyl group-containing organopolysiloxane having an alkenyl group bonded to a silicon atom at the end of the molecular chain: 100 parts by mass, (G) Organohydrogenpolysiloxane having at least two hydrogen atoms bonded to silicon atoms in the molecule: (F) an amount such that there are 0.01 to 3 moles of silicon-bonded hydrogen atoms per mole of alkenyl groups bonded to silicon atoms in the component. (H) Platinum group metal catalyst: 0.01 to 1,000 ppm in terms of the mass of platinum group metal atoms relative to the total amount of components (F) and (G), and (I) Adhesion-improving agent: 0.05 to 20 parts by mass A readily disassembled, addition-curing liquid silicone adhesive is preferred, which contains a material that generates heat by electromagnetic induction and has a content of 3% by mass or less of such material.

[0059] (F) The alkenyl group-containing organopolysiloxane as the base polymer (main component) is a linear diorganopolysiloxane in which the molecular chain ends (molecular chain end or both ends) are sealed with silyl groups having alkenyl groups such as vinyl groups bonded to silicon atoms, and is an organopolysiloxane having an average of at least one, preferably two or more (usually 2 to 20, particularly 2 to 10, and even more than 2 to 5) alkenyl groups bonded to silicon atoms in the molecule. Examples of these alkenyl groups include lower alkenyl groups, usually having 2 to 6 carbon atoms, preferably 2 to 4 carbon atoms, such as vinyl groups, allyl groups, propenyl groups, isopropenyl groups, butenyl groups, hexenyl groups, and cyclohexenyl groups. Furthermore, the alkenyl group-containing organopolysiloxane used as the base polymer (main component) may have alkenyl groups on the side chains of the molecular chain, as long as it has alkenyl groups bonded to silicon atoms at one or both ends of the molecular chain.

[0060] Furthermore, organic groups bonded to silicon atoms other than silicon atom-bonded alkenyl groups are not particularly limited as long as they do not have aliphatic unsaturated bonds. Examples include unsubstituted or substituted monovalent hydrocarbon groups that typically have 1 to 12, preferably 1 to 10, carbon atoms and do not have aliphatic unsaturated bonds. Examples of these unsubstituted or substituted monovalent hydrocarbon groups include alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, and heptyl groups; cycloalkyl groups such as cyclohexyl groups; aryl groups such as phenyl, tolyl, xylyl, and naphthyl groups; aralkyl groups such as benzyl and phenethyl groups; and halogenated alkyl groups such as chloromethyl, 3-chloropropyl, and 3,3,3-trifluoropropyl groups, in which some or all of the hydrogen atoms of these groups are substituted with halogen atoms such as chlorine, fluorine, or bromine atoms. Preferably, alkyl groups and aryl groups are preferred, and more preferably, methyl and phenyl groups.

[0061] Specific examples of alkenyl group-containing organopolysiloxanes include dimethylpolysiloxane with dimethylvinylsiloxy groups sealed at both ends, dimethylsiloxane-methylvinylsiloxane copolymer with dimethylvinylsiloxy groups sealed at both ends, dimethylsiloxane-diphenylsiloxane copolymer with dimethylvinylsiloxy groups sealed at both ends, dimethylsiloxane-methylvinylsiloxane-diphenylsiloxane copolymer with dimethylvinylsiloxy groups sealed at both ends, methyltrifluoropropylpolysiloxane with dimethylvinylsiloxy groups sealed at both ends, and dimethylvinyl Siloxy group-separated dimethylsiloxane / methyltrifluoropropylsiloxane copolymer, both-terminated dimethylvinylsiloxy group-separated dimethylsiloxane / methyltrifluoropropylsiloxane / methylvinylsiloxane copolymer, both-terminated methyldivinylsiloxy group-separated dimethylpolysiloxane, both-terminated methyldivinylsiloxy group-separated dimethylsiloxane / methylvinylsiloxane copolymer, both-terminated methyldivinylsiloxy group-separated dimethylsiloxane / diphenylsiloxane copolymer, both-terminated methyldivinylsiloxy group-separated dimethylsiloxane Methylvinylsiloxane-diphenylsiloxane copolymer, methyltrifluoropropylpolysiloxane with methyldivinylsiloxy groups sealed at both ends, dimethylsiloxane-methyltrifluoropropylsiloxane copolymer with methyldivinylsiloxy groups sealed at both ends, dimethylsiloxane-methyltrifluoropropylsiloxane-methylvinylsiloxane copolymer, dimethylpolysiloxane with trivinylsiloxy groups sealed at both ends, dimethylsiloxane-methylvinylsiloxane copolymer with trivinylsiloxy groups sealed at both ends methylsiloxane-diphenylsiloxane copolymer, trivinylsiloxy group-separated dimethylsiloxane-diphenylsiloxane copolymer, trivinylsiloxy group-separated dimethylsiloxane-methylvinylsiloxane-diphenylsiloxane copolymer, trivinylsiloxy group-separated methyltrifluoropropylpolysiloxane, trivinylsiloxy group-separated dimethylsiloxane-methyltrifluoropropylsiloxane copolymer, trivinylsiloxy group-separated dimethylsiloxane-methyltrifluoropropylsiloxane-methylvinylsiloxane copolymer,Dimethylpolysiloxane with one end trimethylsiloxy group sealed and the other end dimethylvinylsiloxy group sealed; dimethylsiloxane-methylvinylsiloxane copolymer with one end trimethylsiloxy group sealed and the other end dimethylvinylsiloxy group sealed; dimethylsiloxane-diphenylsiloxane copolymer with one end trimethylsiloxy group sealed and the other end dimethylvinylsiloxy group sealed; dimethylsiloxane-methylvinylsiloxane with one end trimethylsiloxy group sealed and the other end dimethylvinylsiloxy group sealed. Examples include diphenylsiloxane copolymers, methyltrifluoropropylpolysiloxane with one end trimethylsiloxy group sealed and the other end dimethylvinylsiloxy group sealed, dimethylsiloxane-methyltrifluoropropylsiloxane copolymers with one end trimethylsiloxy group sealed and the other end dimethylvinylsiloxy group sealed, and dimethylsiloxane-methyltrifluoropropylsiloxane-methylvinylsiloxane copolymers with one end trimethylsiloxy group sealed and the other end dimethylvinylsiloxy group sealed.

[0062] The viscosity of the alkenyl group-containing organopolysiloxane used as the base polymer (main component) at 23°C is preferably 100 to 500,000 mPa·s, and more preferably 700 to 100,000 mPa·s.

[0063] The alkenyl group-containing organopolysiloxane used as the base polymer (main component) may be used alone or in combination of two or more types.

[0064] (G) The organohydrogenpolysiloxane used as a crosslinking agent (curing agent) has, on average, at least two, preferably at least three, more preferably up to 500, even more preferably up to 200, and particularly preferably up to 100 hydrogen atoms (SiH groups) bonded to silicon atoms in the molecule, and preferably does not have aliphatic unsaturated bonds in the molecule.

[0065] In this organohydrogenpolysiloxane, the silicon atom-bonded organic group other than the silicon atom-bonded hydrogen atom is not particularly limited, but examples include unsubstituted or substituted monovalent hydrocarbon groups having typically 1 to 10, preferably 1 to 6, carbon atoms. Specific examples include those similar to those exemplified as silicon atom-bonded organic groups other than the silicon atom-bonded alkenyl group in the description of alkenyl group-containing organopolysiloxanes, as well as alkenyl groups such as vinyl groups and allyl groups. Preferably, these are unsubstituted monovalent hydrocarbon groups without aliphatic unsaturated bonds, such as alkyl groups and aryl groups, and more preferably methyl groups and phenyl groups.

[0066] The number of silicon atoms in the molecule is preferably 2 to 300, particularly 3 to 150, and especially 4 to 100, and the molecule is liquid at room temperature. The hydrogen atoms bonded to the silicon atoms may be located at the ends of the molecular chain, in the middle (non-terminants), or in both. Furthermore, the molecular structure of the organohydrogenpolysiloxane may be linear, cyclic, branched, or three-dimensional network. In this invention, the degree of polymerization (or the number of repeats of the diorganosiloxane units constituting the main chain, which is a measure of the number of silicon atoms in the molecule) can be determined, for example, as the number-average degree of polymerization (or number-average molecular weight) in polystyrene terms in gel permeation chromatography (GPC) analysis using toluene or the like as the developing solvent.

[0067] Examples of organohydrogenpolysiloxanes include 1,1,3,3-tetramethyldisiloxane, 1,3,5,7-tetramethylcyclotetrasiloxane, tris(hydrogendimethylsiloxy)methylsilane, tris(hydrogendimethylsiloxy)phenylsilane, methylhydrogencyclopolysiloxane, methylhydrogensiloxane-dimethylsiloxane cyclic copolymer, methylhydrogenpolysiloxane with trimethylsiloxy group blockade at both ends, dimethylsiloxane-methylhydrogensiloxane copolymer with trimethylsiloxy group blockade at both ends, dimethylpolysiloxane with dimethylhydrogensiloxy group blockade at both ends, and dimethylsiloxy group blockade at both ends. Xan-methylhydrogensiloxane copolymer, methylhydrogensiloxane-diphenylsiloxane copolymer with trimethylsiloxy groups sealed at both ends, methylhydrogensiloxane-diphenylsiloxane-dimethylsiloxane copolymer with trimethylsiloxy groups sealed at both ends, methylhydrogensiloxane-methylphenylsiloxane-dimethylsiloxane copolymer with trimethylsiloxy groups sealed at both ends, methylhydrogensiloxane-dimethylsiloxane-diphenylsiloxane copolymer with dimethylhydrogensiloxy groups sealed at both ends, methylhydrogensiloxane-dimethylsiloxane-methylphenylsiloxane copolymer with dimethylhydrogensiloxy groups sealed at both ends, (CH3)2HSiO 1 / 2 Units and (CH3)3SiO 1 / 2 Units and SiO 4 / 2 A copolymer consisting of units, (CH3)2HSiO 1 / 2 Units and SiO 4 / 2 A copolymer consisting of units, (CH3)2HSiO 1 / 2 Units and SiO 4 / 2 Units and (C6H5)SiO 3 / 2Examples include copolymers consisting of units, and in these exemplary compounds, some or all of the methyl groups are substituted with other alkyl groups or phenyl groups. Furthermore, organohydrogenpolysiloxanes having at least two hydrogen atoms bonded to the silicon atom of component (G) are clearly distinguished from the adhesion-imparting agents of component (I) described later, in that they do not have any silicon atom-bonded organic groups other than the silicon atom-bonded hydrogen atoms in the molecule, such as functional groups like epoxy groups or alkoxysilyl groups.

[0068] Organohydrogenpolysiloxanes may be used individually or in combination of two or more types.

[0069] The amount of organohydrogenpolysiloxane added is such that, for every mole of alkenyl groups bonded to silicon atoms in the alkenyl group-containing organopolysiloxane, there are 0.01 to 3 moles, preferably 0.05 to 2.5 moles, and more preferably 0.2 to 2 moles of silicon-bonded hydrogen atoms (SiH groups).

[0070] (H) Platinum group metal catalysts (hydrosilylation addition reaction catalysts) are used as catalysts to promote the addition reaction between silicon-bonded alkenyl groups in alkenyl group-containing organopolysiloxanes and silicon-bonded hydrogen atoms in organohydrogenpolysiloxanes. Known platinum group metal catalysts can be used. Specific examples include 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 acetylene alcohols.

[0071] The amount of platinum group metal catalyst can be adjusted as needed depending on the desired curing rate, but it is typically in the range of 0.01 to 1,000 ppm, preferably 0.1 to 500 ppm, and more preferably 1 to 300 ppm, based on the mass of platinum group metal atoms relative to the total amount of alkenyl group-containing organopolysiloxane and organohydrogenpolysiloxane. If the amount is too high, the heat resistance of the resulting cured product may decrease.

[0072] Component (I) is an adhesion-imparting agent that imparts self-adhesion to the composition of the present invention. This self-adhesion is preferably particularly good for metals and organic resins. Examples of component (I) include organosilanes having at least one, preferably two or more, functional groups selected from the group consisting of an alkenyl group such as a vinyl group, a (meth)acryloxy group, a hydrosilyl group (SiH group), an epoxy group, an alkoxysilyl group, a carbonyl group, and a phenyl group; organosilicon compounds containing functional groups such as cyclic or linear organopolysiloxanes having 2 to 30, preferably 4 to 20 silicon atoms (excluding components (F) and (G)); and non-silicon hydrocarbon compounds (i.e., those that do not contain silicon atoms in the molecule) that contain 1 to 4, preferably 1 to 2, aromatic rings such as a phenylene structure with a 1 to 4 valency, preferably 2 to 4 valency, per molecule, and contain at least one, preferably 2 to 4, functional groups (e.g., an alkenyl group, a (meth)acryloxy group) that can contribute to the hydrosilylation addition reaction, and which may contain oxygen atoms in the molecule.

[0073] Examples of such component (I) include functional group-containing organoalkoxysilanes and functional group-containing organohydrogenpolysiloxanes as exemplified below, as well as functional group-containing organosilicon compounds in which the total number of repeating bifunctional siloxane units is any positive integer in the functional group-containing linear organohydrogenpolysiloxanes in the exemplified compounds below is between 3 and 28, as well as bisphenol compounds (bisphenol F, bisphenol A, bisphenol AF, etc.) or derivatives thereof in which the hydroxyl groups at both ends of the molecular chain are occluded with alkenyloxy groups or (meth)acryloxy-substituted alkyloxy groups.

[0074] [ka] [ka]

[0075] (I) Component can be used alone or in combination of two or more, but from the viewpoint of adhesion to the substrate, it is preferable to use an organosilicon compound and a nonsilicon-based organic compound in combination.

[0076] The amount of component (I) is such that the composition of the present invention can obtain good self-adhesion to the adherend, particularly metals and organic resins, and 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 per 100 parts by mass of component (F). If the amount is less than 0.05 parts by mass, sufficient adhesion may not be obtained, and if it exceeds 20 parts by mass, the resulting cured product may have inferior weather resistance and mechanical properties.

[0077] In addition to the components mentioned above, optional components may be added to the addition reaction curing liquid silicone adhesive, provided that they do not impair the objectives of the present invention. Examples of these optional components include reaction inhibitors, inorganic fillers similar to those exemplified in the condensation curing liquid silicone adhesive described above (excluding hydroxide compounds whose decomposition temperature for component (A) is 180 to 600°C), organopolysiloxanes that do not contain silicon-bonded hydrogen atoms (SiH groups) or silicon-bonded alkenyl groups (so-called non-functional silicone oils), heat-resistant additives, flame retardants, thixotropic agents, pigments, dyes, and the like.

[0078] Addition-curing liquid silicone adhesives can be prepared by uniformly mixing the above-mentioned components using a known mixer in accordance with conventional methods.

[0079] Furthermore, the curing conditions for addition-curing liquid silicone adhesives can be 23 to 150°C, particularly 23 to 100°C, for 10 minutes to 8 hours, and especially 30 minutes to 5 hours.

[0080] [UV-curing liquid silicone adhesive] UV-curing liquid silicone adhesives are liquid silicone adhesives that, in addition to (A) a hydroxide compound with a decomposition temperature of 180-600°C as described above, contain (J) UV-reactive organopolysiloxane (base polymer) and (K) a photopolymerization initiator, and obtain a cured product by crosslinking upon irradiation with ultraviolet light. As for UV-curing liquid silicone adhesives, (A) Hydroxide compounds with a decomposition temperature of 180-600°C: in an amount that is 25-80% by mass of the total adhesive. (J) UV-reactive organopolysiloxane: 100 parts by mass, and (K) Photopolymerization initiator: 0.01 to 10 parts by mass A readily disassembled, UV-curable liquid silicone adhesive is preferred, which contains a material that generates heat by electromagnetic induction and has a content of 3% by mass or less of such material.

[0081] The UV-reactive organopolysiloxane of component (J) is not particularly limited as long as it acts as a base polymer in UV-curable silicone compositions, and is preferably an organopolysiloxane having at least 2 UV-reactive groups per molecule, more preferably 2 to 20, and particularly preferably 2 to 10. The UV-reactive groups present in this organopolysiloxane may all be the same or different.

[0082] Examples of UV-reactive groups include alkenyl groups such as vinyl, allyl, and propenyl groups; alkenyloxy groups such as vinyloxy, allyloxy, propenyloxy, and isopropenyloxy groups; aliphatic unsaturated groups other than alkenyl groups such as acryloyl and methacryloyl groups; epoxy groups; and hydrosilyl groups. Preferably, acryloyl, methacryloyl, mercapto, epoxy, and hydrosilyl groups are used, and more preferably, acryloyl and methacryloyl groups are used.

[0083] Furthermore, organic groups bonded to silicon atoms other than silicon atom-bonded alkenyl groups are not particularly limited as long as they do not have aliphatic unsaturated bonds. Examples include unsubstituted or substituted monovalent hydrocarbon groups that typically have 1 to 12, preferably 1 to 10, carbon atoms and do not have aliphatic unsaturated bonds. Examples of these unsubstituted or substituted monovalent hydrocarbon groups include alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, and heptyl groups; cycloalkyl groups such as cyclohexyl groups; aryl groups such as phenyl, tolyl, xylyl, and naphthyl groups; aralkyl groups such as benzyl and phenethyl groups; and halogenated alkyl groups such as chloromethyl, 3-chloropropyl, and 3,3,3-trifluoropropyl groups, in which some or all of the hydrogen atoms of these groups are substituted with halogen atoms such as chlorine, fluorine, or bromine atoms. Preferably, alkyl groups and aryl groups are preferred, and more preferably, methyl and phenyl groups.

[0084] Specific examples of UV-reactive group-containing organopolysiloxanes include dimethylpolysiloxane with dimethylvinylsiloxy groups sealed at both ends, dimethylsiloxane-methylvinylsiloxane copolymer with dimethylvinylsiloxy groups sealed at both ends, dimethylsiloxane-diphenylsiloxane copolymer with dimethylvinylsiloxy groups sealed at both ends, dimethylpolysiloxane with dimethylacryloylsiloxy groups sealed at both ends, dimethylsiloxane-methylvinylsiloxane copolymer with dimethylacryloylsiloxy groups sealed at both ends, and dimethylpolysiloxane with dimethylacryloylsiloxy groups sealed at both ends. Siloxane-diphenylsiloxane copolymer, dimethyl methacryloylsiloxy group-separated dimethylpolysiloxane, dimethyl methacryloylsiloxy group-separated dimethylsiloxane-methylvinylsiloxane copolymer, dimethyl methacryloylsiloxy group-separated dimethylsiloxane-diphenylsiloxane copolymer, dimethyl mercaptosiloxy group-separated dimethylpolysiloxane, dimethyl mercaptosiloxy group-separated dimethylsiloxane-methylvinylsiloxane copolymer, dimethyl mercaptosiloxy group-separated di Methylsiloxane-diphenylsiloxane copolymer, dimethylpolysiloxane with dimethyl epoxysiloxy groups sealed at both ends, dimethylsiloxane-methylvinylsiloxane copolymer with dimethyl epoxysiloxy groups sealed at both ends, dimethylsiloxane-diphenylsiloxane copolymer with dimethyl epoxysiloxy groups sealed at both ends, dimethylpolysiloxane with methyldivinylsiloxy groups sealed at both ends, dimethylsiloxane-methylvinylsiloxane copolymer with methyldivinylsiloxy groups sealed at both ends, dimethylsiloxane-diphenylsiloxane copolymer with methyldivinylsiloxy groups sealed at both ends Nylsiloxane copolymer, dimethylpolysiloxane with methyldiacryloylsiloxy groups sealed at both ends, dimethylsiloxane / methylvinylsiloxane copolymer with methyldiacryloylsiloxy groups sealed at both ends, dimethylsiloxane / diphenylsiloxane copolymer with methyldiacryloylsiloxy groups sealed at both ends, dimethylpolysiloxane with trivinylsiloxy groups sealed at both ends, dimethylsiloxane / methylvinylsiloxane copolymer with trivinylsiloxy groups sealed at both ends, dimethylsiloxane / diphenylsiloxane copolymer with trivinylsiloxy groups sealed at both ends,Examples include dimethylpolysiloxane with one end trimethylsiloxy group sealed and the other end dimethylvinylsiloxy group sealed, dimethylsiloxane-methylvinylsiloxane copolymer with one end trimethylsiloxy group sealed and the other end dimethylvinylsiloxy group sealed, and dimethylsiloxane-diphenylsiloxane copolymer with one end trimethylsiloxy group sealed and the other end dimethylvinylsiloxy group sealed.

[0085] The viscosity of UV-reactive organopolysiloxanes at 23°C is preferably 100 to 500,000 mPa·s, and more preferably 700 to 100,000 mPa·s.

[0086] UV-reactive organopolysiloxanes may be used individually or in combination of two or more types.

[0087] The photopolymerization initiator of component (K) has the effect of promoting the photopolymerization of the ultraviolet-reactive group in component (J). Component (K) is not particularly limited, and specific examples include acetophenone, propiophenone, benzophenone, xanthol, fluoreine, 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 methoxyacetal, 2-chlorothioxanthone Examples include santon, diethylacetophenone, 1-hydroxychlorophenyl ketone, 1-hydroxycyclohexylphenyl ketone, 2-methyl-(4-(methylthio)phenyl)-2-morpholino-1-propane, 2,2-dimethoxy-2-phenylacetophenone, diethoxyacetophenone, and 2-hydroxy-2-methyl-1-phenylpropan-1-one. Preferably, from the viewpoint of high purity, benzophenone, 4-methoxyacetophenone, 4-methylbenzophenone, diethoxyacetophenone, 1-hydroxycyclohexylphenyl ketone, and 2-hydroxy-2-methyl-1-phenylpropan-1-one are selected, and more preferably, diethoxyacetophenone, 1-hydroxycyclohexylphenyl ketone, and 2-hydroxy-2-methyl-1-phenylpropan-1-one are selected. These photopolymerization initiators may be used individually or in combination of two or more.

[0088] (K) component's addition amount is not particularly limited, but with respect to 100 parts by mass of component (J), it is preferably 0.01 to 10 parts by mass, more preferably 0.1 to 3 parts by mass, and even more preferably 0.5 to 3 parts by mass. When the addition amount of component (K) is within this range, it is easy to control the curing of the ultraviolet-curable liquid silicone-based adhesive.

[0089] The ultraviolet-curable liquid silicone-based adhesive can also use a liquid silicone-based adhesive having both an ultraviolet-curable type and a condensation-curable type, or a liquid silicone-based adhesive having both an ultraviolet-curable type and an addition-curable type.

[0090] The liquid silicone-based adhesive having both an ultraviolet-curable type and a condensation-curable type uses, together with the above-mentioned hydroxide compound with a decomposition temperature of 180 to 600 °C for (A), component (B) as the base polymer, component (J) as mentioned above, component (C) as the curing agent mentioned above, a component having both a substituent that reacts with ultraviolet rays and a substituent that condenses, component (D) as the condensation-curing catalyst mentioned above, component (K) as the ultraviolet-curing catalyst mentioned above, and component (E) as the adhesion-imparting component mentioned above.

[0091] The liquid silicone-based adhesive having both an ultraviolet-curable type and an addition-curable type uses, together with the above-mentioned hydroxide compound with a decomposition temperature of 180 to 600 °C for (A), component (F) as the base polymer, component (J) as mentioned above, component (G) as the curing agent mentioned above, component (H) as the addition-curing catalyst mentioned above, component (K) as the ultraviolet-curing catalyst mentioned above, and component (I) as the adhesion-imparting component mentioned above.

[0092] The ultraviolet-curable liquid silicone-based adhesive can be prepared by uniformly mixing the above-mentioned respective components according to a conventional method using a known mixer.

[0093] The ultraviolet-curable liquid silicone-based adhesive cures by irradiating with ultraviolet rays. The ultraviolet irradiation conditions are not particularly limited, but using an ultraviolet light-emitting diode having an emission wavelength of 365 nm, the illuminance is 5 to 500 mW / cm 2 , preferably 10 to 200 mW / cm2 , light intensity 0.5~100J / cm 2 Preferably 10-50 J / cm² 2 It is preferable to do so.

[0094] [Joining member] In the method for disassembling a jointed member of the present invention, the jointed member is formed by joining multiple (particularly two) members, including a member whose joint interface is metal, using a cured product (adhesive member made of adhesive silicone rubber) obtained by curing a curable liquid silicone adhesive that contains a specific amount of a hydroxide compound having a decomposition temperature of 180 to 600°C and has a content of 3% by mass or less of a material that generates heat by electromagnetic induction. The members may be the same or different types of members. In the joining member, one of the joined members may be a member in which at least a portion of the joining interface is metal, and the other member may be selected from the same member (a member in which at least a portion of the joining interface is metal), an organic resin member, and a metal member.

[0095] A component in which at least a portion of the bonding interface is metal only needs to have metal at least at the bonding interface, and may be entirely metal. Furthermore, the metal at the bonding interface of the component only needs to have an area that is sufficiently heated by electromagnetic induction.

[0096] Examples of components in which at least a portion of the bonding interface is metal include automotive parts and electrical / electronic components made from aluminum alloys such as A1050, A2017, A5052, A5083, A6061, and A1N30; aluminum alloy die-casts such as ADC1, ADC3, ADC10, ADC12, and ADC14; carbon steels such as SPCC, SS400, and SAPH; stainless steels such as SUS304 and SUS430; and magnesium alloys such as AZ-91D and AM50A.

[0097] The components in which at least a portion of the bonding interface is metal, and the metal constituting the metal components, may be either magnetic or non-magnetic materials, as long as they are metals capable of generating heat by electromagnetic induction. Examples include pure metals such as aluminum, iron, and copper, and alloys containing these (aluminum alloys (aluminum alloy die-casts such as Al-Cu-Si alloys (ADC12)), carbon steel (SPCC, SS400, SAPH, etc.), cast iron (Fe-Si-C ternary alloys), stainless steel (especially ferritic), copper alloys (brass, bronze, cupronickel), nichrome, magnesium alloys (AZ-91D, AM50A, etc.), titanium alloys, etc.). Note that magnetic materials are defined as follows: Permeability of vacuum (μ0) against Initial permeability (μ) This refers to a metal material whose relative permeability (μ / μ0), which is the ratio of the magnetic particles to the magnetic field, is 5 or higher, and even 50 or higher.

[0098] Examples of organic resins used to make up organic resin components include polyamide resins such as PBT (polybutylene terephthalate resin), PPS (polyphenylene sulfide resin), PA66 (nylon 66), PA6 (nylon 6), and PC (polycarbonate resin).

[0099] Furthermore, it is desirable that the organic resin or metal constituting the member, organic resin member, or metal member, in which at least a portion of the bonding interface is metal, have a heat resistance temperature of 160°C or higher.

[0100] [Method for manufacturing joint members] A curable liquid silicone adhesive containing a hydroxide compound with a decomposition temperature of 180-600°C and containing 3% by mass or less of a material that generates heat by electromagnetic induction is applied to the surface of one of the components in the shape of the joint (e.g., a gasket) by hand or machine dispensing, the other component is then attached and joined, and allowed to cure. Afterwards, it is secured with bolts or other means as needed. If the curable liquid silicone adhesive of the present invention is a condensation-curing type liquid silicone adhesive, it hardens at room temperature due to moisture in the air, so hardening will proceed if multiple components are joined and left to stand. Humidification is effective if the hardening speed is to be increased. If the curable liquid silicone adhesive of the present invention is an addition-reaction type liquid silicone adhesive, it hardens by an addition reaction at a temperature of 23 to 150°C, so hardening will proceed if multiple components are joined and left to stand or heated. If the curable liquid silicone adhesive of the present invention is an ultraviolet-curing type liquid silicone adhesive, irradiation with ultraviolet light causes the photopolymerization initiator to react, the hardening reaction to proceed, and hardening occurs. Secondary curing may be performed as needed, and the temperature conditions in this case are preferably 120°C or higher, more preferably 150°C or higher, below the decomposition temperature of the hydroxide compound and 250°C or lower. The curing time in this case is preferably 10 minutes to 48 hours, and even more preferably 30 minutes to 24 hours.

[0101] Examples of the above-mentioned joining members include automotive parts such as engines, transmissions, and automotive electrical components (ECUs (Electronic Control Units) and PCUs (Power Control Units)), as well as electrical and electronic components such as smartphones, tablets, LCDs, and batteries. Automotive parts and electrical and electronic components are preferred.

[0102] The above-mentioned joining members maintain their bonded state at an ambient temperature of 150°C or lower, preferably room temperature to 120°C.

[0103] The above-mentioned joint members are preferably easily disassembled joint members that are joined with a certain degree of adhesive strength during normal use, and whose adhesive strength decreases to the extent that the members can be separated after electromagnetic induction heating. Specifically, it is preferable that the initial shear adhesive strength of the above-mentioned joint members is 1.2 MPa or more, particularly 1.5 MPa or more, and that the shear adhesive strength after electromagnetic induction heating of the joint members is 1 MPa or less. This shear adhesive strength is a value measured in accordance with the method specified in JIS K6850. In order to achieve the above range for the initial and post-electromagnetic induction heating shear adhesive strengths, this can be achieved by setting the composition of the curable liquid silicone adhesive to the specific range described above.

[0104] [Disassembly method] The present invention provides a method for disassembling a joint member. This method involves heating the metal portion of the joint interface of the joint member by electromagnetic induction. The cured product (adhesive silicone rubber cured product), formed by indirectly curing a curable liquid silicone adhesive, is heated to 160°C to 800°C in the portion of the cured product that is in contact with the metal. This heats the metal portion or the entire product to 160°C to 800°C, allowing the metal member to detach naturally, or to be removed by applying force by hand or by using a tool such as a scraper. The disassembled member can then be recycled.

[0105] It is presumed that the dismantling of the component according to the present invention will be possible for the following reasons. The metal and adhesive forming the joint interface have a large difference in their coefficients of thermal expansion. Therefore, when heated, the difference in thermal expansion causes significant thermal stress at the joint interface. Furthermore, in the case of joints made of dissimilar materials, thermal stress is also exerted between the joint members due to the difference in thermal expansion. Moreover, when the metal at the joint interface is heated by electromagnetic induction, the hydroxide compound of component (A) in the cured product (adhesive silicone rubber cured product) formed by curing the curable liquid silicone adhesive, which is the adhesive member, is heated and decomposes to generate water. This water then vaporizes, causing foaming and reducing the adhesive strength. As a result, the joint can be disassembled more quickly.

[0106] For electromagnetic induction heating, a frequency, output, and time that allows for the separation of components are preferred. The frequency can be selected within the range of 100 kHz to 500 kHz, and the output within the range of 500 W to 5 kW. The heating time by electromagnetic induction is not particularly limited, but is 2 minutes or less, preferably 1 minute or less, and more preferably 20 seconds or less. [Examples]

[0107] Next, the present invention will be specifically described by showing examples of compositions, comparative examples of compositions, examples, and comparative examples, but the present invention is not limited to the following examples. In the following examples, the room temperature is 23°C, the viscosity is the value measured at 23°C using a rotational viscometer, and the average particle diameter is the value obtained as the cumulative weight average D50 (or median diameter) using a particle size distribution analyzer by laser light diffraction. The BET specific surface area is the value calculated using the BET formula from the isothermal adsorption curve measured by the nitrogen gas adsorption method.

[0108] Preparation of a curable liquid silicone adhesive (composition) [Composition Example 1] The composition comprises 70 parts by mass of dimethylpolysiloxane with trimethoxysilyl groups encapsulated at both ends of the molecular chain and a viscosity of 30,000 mPa·s, 40 parts by mass of dimethylpolysiloxane with trimethylsilyl groups encapsulated at both ends of the molecular chain and a viscosity of 100 mPa·s, an average particle size of 10 μm, 80 parts by mass of untreated aluminum hydroxide (31.0% by mass in the total composition), and a BET specific surface area of ​​17 m². 2 Composition 1 was obtained by uniformly mixing 50 parts by mass of colloidal calcium carbonate with a surface treated with fatty acids, 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(ethylacetoacetate). [ka]

[0109] [Composition Example 2] The composition comprises 85 parts by mass of dimethylpolysiloxane with hydroxyl groups encapsulated at both ends of the molecular chain and a viscosity of 20,000 mPa·s, 15 parts by mass of dimethylpolysiloxane with trimethylsilyl groups encapsulated at both ends of the molecular chain and a viscosity of 100 mPa·s, an average particle size of 10 μm, 70 parts by mass of untreated aluminum hydroxide (31.9% by mass of the total composition), and a BET specific surface area of ​​2.0 m². 2 The ratio is / g, and it consists of 30 parts by mass of heavy calcium carbonate with a paraffin-treated surface and BET with a specific surface area of ​​120 m² with a dimethyldichlorosilane-treated surface. 2 Composition 2 was obtained by uniformly mixing 9 parts by mass of fumarole silica (1 / g), 9.2 parts by mass of vinyltris(1-cyclopenten-1-yloxy)silane, 0.4 parts by mass of γ-(N,N,N',N'-tetramethylguanidyl)propyltrimethoxysilane, 0.4 parts by mass of the compound represented by formula (1) above, and 0.4 parts by mass of γ-aminopropyltriethoxysilane.

[0110] [Composition Example 3] The composition comprises 70 parts by mass of dimethylpolysiloxane with trimethoxysilyl groups encapsulated at both ends of the molecular chain and a viscosity of 30,000 mPa·s, 40 parts by mass of dimethylpolysiloxane with trimethylsilyl groups encapsulated at both ends of the molecular chain and a viscosity of 100 mPa·s, an average particle size of 10 μm, 80 parts by mass of untreated aluminum hydroxide (30.8% by mass in the total composition), and a BET specific surface area of ​​17 m². 2 Composition 3 was obtained by uniformly mixing 50 parts by mass of colloidal calcium carbonate with a surface treated with fatty acids, 2 parts by mass of iron powder with an average particle size of 30 μm (0.8% by mass of the total composition), 8 parts by mass of vinyltrimethoxysilane, 2 parts by mass of the compound represented by formula (1) above, and 0.8 parts by mass of diisopropoxytitanium bis(ethyl acetate).

[0111] [Comparative Example of Composition 1] 70 parts by mass of dimethylpolysiloxane with trimethoxysilyl groups encapsulated at both ends of the molecular chain and a viscosity of 30,000 mPa·s, 40 parts by mass of dimethylpolysiloxane with trimethylsilyl groups encapsulated at both ends of the molecular chain and a viscosity of 100 mPa·s, 5 parts by mass of fuzzy silica, BET specific surface area 17 m² 2 Composition 4 was obtained by uniformly mixing 50 parts by mass of colloidal calcium carbonate with a surface treated with fatty acids, 8 parts by mass of vinyltrimethoxysilane, 2 parts by mass of the compound represented by formula (1) above, and 0.8 parts by mass of diisopropoxytitanium bis(ethylacetoacetate).

[0112] [Comparative Example of Composition 2] The composition comprises 70 parts by mass of dimethylpolysiloxane with trimethoxysilyl groups encapsulated at both ends of the molecular chain and a viscosity of 30,000 mPa·s, 40 parts by mass of dimethylpolysiloxane with trimethylsilyl groups encapsulated at both ends of the molecular chain and a viscosity of 100 mPa·s, an average particle size of 10 μm, and 100 parts by mass of untreated aluminum hydroxide (30.5% by mass in the total composition), with a BET specific surface area of ​​17 m². 2 Composition 5 was obtained by uniformly mixing 50 parts by mass of colloidal calcium carbonate with a surface treated with fatty acids, 50 parts by mass of iron powder with an average particle size of 30 μm (15.2% by mass of the total composition), 8 parts by mass of vinyltrimethoxysilane, 2 parts by mass of the compound represented by formula (1) above, and 0.8 parts by mass of diisopropoxytitanium bis(ethyl acetate).

[0113] [Fabrication of joining members] A 25mm wide, 50mm long ADC12 (aluminum alloy die-cast) substrate and a 25mm wide, 50mm long PBT (polybutylene terephthalate resin, heat resistance temperature: 150℃ or higher) substrate are used as base materials, and one of the above compositions 1 to 5 is used as a curable liquid silicone adhesive, with a bonding thickness of 0.5mm and a bonding area of ​​2.5cm². 2 A DC12 substrate and a PBT substrate were bonded together in this manner, and a bonded member was fabricated by curing at 23°C / 50%RH for 7 days, resulting in a cured product of a curable liquid silicone adhesive (cured adhesive silicone rubber).

[0114] Evaluation of demolition feasibility [Examples 1-3, Comparative Examples 1-2] The joint members fabricated as described above were evaluated using the evaluation method shown below. The results are shown in Table 1, Figure 1, and Figure 2.

[0115] (1) Initial adhesive strength The shear bonding strength was measured using the joint members prepared as described above, in accordance with the method specified in JIS K6850.

[0116] (2) Time until demolition For electromagnetic induction heating, we used EASYHEAT0224 manufactured by Aronics Co., Ltd. Electromagnetic induction heating was performed at a frequency of 286 kHz and an output of 2.3 kW. The metal portion of the bonding interface was heated, and heating continued until the bonded components separated. The time taken for separation was measured with a stopwatch; a time of 15 seconds or less was considered a pass, while a time exceeding 15 seconds was considered a fail. In all compositions, the bonded components were separated solely by heating.

[0117] (3) Condition of the disassembled joint surface for electromagnetic induction heating The condition of the bonding surfaces of the disassembled ADC12 substrates was observed using a Keyence VHX8000 digital microscope. Figure 1 shows the condition before electromagnetic induction heating in Example 1, and Figure 2 shows the condition after electromagnetic induction heating. In addition, the remaining adhesive on the PBT substrate side was scraped off with a utility knife, and the surface condition was visually checked. Substrates where there was no change in the surface condition before and after electromagnetic induction heating of the ADC12 and PBT substrates were defined as "no change".

[0118] (4) Adhesion after recycling The recyclability of the disassembled components was confirmed using electromagnetic induction heating. The ADC12 substrate was used as is, while the PBT substrate was used after the adhesive was scraped off with a utility knife, completely removed with a silicone decomposing agent (silicone cleaner X-100), washed with water, and dried. The jointed components were manufactured using the same method as above. The shear adhesive strength was measured according to the method specified in JIS K6850.

[0119] [Table 1]

[0120] As is clear from the results above, the dismantling method for the joint members of the present invention, as described in Examples 1 to 3, allows for easy dismantling in a short time of 12 to 14 seconds using electromagnetic induction heating, with low energy consumption, and furthermore, the members can be recycled. On the other hand, while Comparative Example 1 could be dismantled, the absence of hydroxide compounds meant that the effect of reducing adhesive strength due to foaming was not achieved, and the time until dismantling was extended, but it was still recyclable. In Comparative Example 2, 15.2% by mass of metal powder was added to the composition, causing the adhesive to heat up and the PBT substrate to dissolve, making recycling impossible.

Claims

1. A method for dismantling a jointed member, comprising the step of separating the member containing the metal from the other members by heating the metal portion of the joint interface by electromagnetic induction, wherein the jointed member is formed by curing a curable liquid silicone adhesive which contains 25 to 80% by mass of a hydroxide compound having a decomposition temperature of 180 to 600°C and a material content of 3% by mass or less that generates heat by electromagnetic induction, and the jointed member is formed by curing a plurality of members including a member whose joint interface is at least a part of metal.

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

3. The method for disassembling a joint 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 hydroxide oxide (boehmite).

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

5. A method for disassembling a joining member according to claim 1, wherein the joining member is an automobile part or an electrical / electronic component.

6. An easily disassembled condensation-curing liquid silicone adhesive containing the following components (A) to (E) used in a method for disassembling a joint member according to any one of claims 1 to 5, wherein the content of a material that generates heat by electromagnetic induction is 3% by mass or less. (A) Hydroxide compounds with a decomposition temperature of 180 to 600°C: in an amount that is 25 to 80% by mass of the total adhesive, (B) A linear diorganopolysiloxane in which both ends of the molecular chain are sealed with hydroxyl groups and / or hydrolyzable silyl groups bonded to silicon atoms: 100 parts by mass, (C) Hydrolyzable organosilane compounds and / or partially hydrolyzed condensates thereof having three or more hydrolyzable groups bonded to silicon atoms in the molecule: 0.1 to 40 parts by mass, (D) Curing catalyst: 0.001 to 20 parts by mass, and (E) Silane coupling agent: 0.05 to 20 parts by mass.

7. An easily disassembled addition-curing liquid silicone adhesive containing the following components (A) and (F) to (I), used in a method for disassembling a joint member according to any one of claims 1 to 5, wherein the content of a material that generates heat by electromagnetic induction is 3% by mass or less. (A) Hydroxide compounds with a decomposition temperature of 180 to 600°C: in an amount that is 25 to 80% by mass of the total adhesive, (F) Alkenyl group-containing organopolysiloxane having an alkenyl group bonded to a silicon atom at the end of the molecular chain: 100 parts by mass, (G) Organohydrogenpolysiloxane having at least two hydrogen atoms bonded to silicon atoms in the molecule: (F) an amount such that there are 0.01 to 3 moles of silicon-bonded hydrogen atoms per mole of alkenyl groups bonded to silicon atoms in the component. (H) Platinum group metal catalyst: 0.01 to 1,000 ppm in terms of the mass of platinum group metal atoms relative to the total amount of components (F) and (G), and (I) Adhesion-improving agent: 0.05 to 20 parts by mass.

8. An easily disassembled, ultraviolet-curable liquid silicone adhesive containing the following components (A), (J), and (K), used in a method for disassembling a joint member according to any one of claims 1 to 5, wherein the content of a material that generates heat by electromagnetic induction is 3% by mass or less. (A) Hydroxide compounds with a decomposition temperature of 180 to 600°C: in an amount that is 25 to 80% by mass of the total adhesive, (J) UV-reactive organopolysiloxane: 100 parts by mass, and (K) Photopolymerization initiator: 0.01 to 10 parts by mass.

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