Classifications

• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J183/00—Adhesives based on macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing silicon, with or without sulfur, nitrogen, oxygen, or carbon only; Adhesives based on derivatives of such polymers
  • C09J183/04—Polysiloxanes
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L83/00—Compositions of macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon only; Compositions of derivatives of such polymers
  • C08L83/04—Polysiloxanes
  • C08L83/06—Polysiloxanes containing silicon bound to oxygen-containing groups
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K3/00—Use of inorganic substances as compounding ingredients
  • C08K3/01—Use of inorganic substances as compounding ingredients characterized by their specific function
  • C08K3/013—Fillers, pigments or reinforcing additives
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K3/00—Use of inorganic substances as compounding ingredients
  • C08K3/34—Silicon-containing compounds
  • C08K3/36—Silica
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K5/00—Use of organic ingredients
  • C08K5/54—Silicon-containing compounds
  • C08K5/541—Silicon-containing compounds containing oxygen
  • C08K5/5415—Silicon-containing compounds containing oxygen containing at least one Si—O bond
  • C08K5/5419—Silicon-containing compounds containing oxygen containing at least one Si—O bond containing at least one Si—C bond
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K5/00—Use of organic ingredients
  • C08K5/54—Silicon-containing compounds
  • C08K5/544—Silicon-containing compounds containing nitrogen
  • C08K5/5477—Silicon-containing compounds containing nitrogen containing nitrogen in a heterocyclic ring
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K5/00—Use of organic ingredients
  • C08K5/54—Silicon-containing compounds
  • C08K5/548—Silicon-containing compounds containing sulfur
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G77/00—Macromolecular compounds obtained by reactions forming a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon in the main chain of the macromolecule
  • C08G77/04—Polysiloxanes
  • C08G77/14—Polysiloxanes containing silicon bound to oxygen-containing groups
  • C08G77/16—Polysiloxanes containing silicon bound to oxygen-containing groups to hydroxy groups

Definitions

• the present invention relates to a room temperature curing silicone composition that is particularly useful as an adhesive.
• Curable polyorganosiloxane compositions which exhibit fluidity in an uncured state and form a rubber-like elastomer (silicone rubber) upon curing, are known as materials with excellent heat resistance, cold resistance, weather resistance, and electrical insulation. Curable polyorganosiloxane compositions are used in various industrial fields for parts such as O-rings, packings, and gaskets, and as adhesives between substrates. In particular, there is an increasing demand for bonding metals such as aluminum and aluminum die casting, and engineering plastics such as PBT and PET with silicone. In response to these demands, silicone resin compositions with added sulfur-based compounds have been proposed to improve adhesion to substrates and compression set (Patent Documents 1 and 2).
• Curable silicone compositions are classified into addition reaction type and condensation reaction type according to the curing mechanism.
• the addition reaction type can be cured in a short time by heating, and has the characteristic of excellent curing properties even in areas where the supply of moisture in the air is insufficient.
• the condensation reaction type requires a long time to cure, but has the characteristic of curing at room temperature and exhibiting good adhesive properties. Room temperature curing silicone compositions do not require a lot of energy for curing conditions, so they function as adhesives suitable for recent changes in environmental awareness.
• condensation reaction type (room temperature) curable polyorganosiloxane compositions additives such as fillers and light stabilizers have been added to improve fluidity, non-sag properties, extrusion properties, adhesive properties, and adhesive durability (for example, Patent Documents 3 and 4).
• the durability of the adhesive is measured in terms of water resistance by tests such as salt spray tests and water immersion tests.
• the adhesive site is often exposed to wind and rain, as well as harsh environments involving heating.
• contact with oil at the adhesive site is also possible. Therefore, it is necessary for the adhesive to have water and oil resistance to increase its reliability. It is desirable to be able to maintain adhesion for a long period of time, such as several years.
• existing products do not yet have sufficient water and oil resistance.
• conventionally used adhesion promoters such as aminosilanes couple with condensation catalysts, and when the catalyst is a Group IV metal atom such as titanium, this significantly reduces the curing property and ultimately the adhesion.
• the object of the present invention is to provide a moisture-curable silicone composition that has high adhesiveness and excellent resistance to water, salt water, and oil.
• the inventors have conducted research and discovered that a silicone composition that can solve the above problems can be obtained by using a hydrolyzable compound that has a cyclic structure, particularly an aromatic ring or heterocyclic ring, and that contains a thioether bond as an adhesive aid, which has led to the creation of the present invention.
• the present invention provides a moisture-curable silicone composition that has high adhesiveness and excellent resistance to water, salt water, and oil. That is, the present invention relates to the following [1] to [6].
• [1] (A) a polyorganosiloxane having two or more hydroxyl groups or hydrolyzable groups bonded to silicon atoms in one molecule; (B) a siloxane compound having two or more -OR2 groups bonded to silicon atoms (wherein R2 in each occurrence is independently a hydrogen atom or a monovalent organic group) in one molecule; (C) a condensation catalyst;
• a moisture-curable silicone composition comprising: (D) a silicon-based adhesion promoter (excluding those corresponding to (A) or (B) above) which has in one molecule one or more adhesion-imparting functional groups selected from the group consisting of aromatic hydrocarbon-containing groups, epoxy group-containing groups, and linear, branched or cyclic aliphatic unsaturated hydrocarbon groups, and
• component (A) contains a linear polyorganosiloxane in which both terminals are blocked with R a 3-m R 3 m SiO 1/2 units and intermediate units are R 3 2 SiO 2/2 units (wherein R a is a hydroxyl group or a hydrolyzable group, R 3 is a hydrogen atom or a monovalent hydrocarbon group having no aliphatic unsaturated bonds, and m is 0, 1, or 2).
• the present invention relates to a moisture-curable silicone composition
• a moisture-curable silicone composition comprising: (A) a polyorganosiloxane having two or more hydroxyl groups or hydrolyzable groups bonded to silicon atoms in one molecule; (B) a siloxane compound having two or more -OR 2 groups bonded to silicon atoms in one molecule (wherein R 2 is, independently in each occurrence, a hydrogen atom or a monovalent organic group); (C) a condensation catalyst; (D) a silicon-based adhesion promoter (excluding those corresponding to (A) or (B) above) which is a compound having, in one molecule, one or more adhesion-imparting functional groups selected from the group consisting of aromatic hydrocarbon-containing groups, epoxy group-containing groups, and linear, branched, or cyclic aliphatic unsaturated hydrocarbon groups, and which has at least one heteroatom in one molecule other than the adhesion-imparting functional groups; and (E) an
• organic group refers to a group containing carbon.
• the valence of an organic group is indicated by describing it as “n-valent,” where n is any natural number.
• n is any natural number.
• a “monovalent organic group” refers to a carbon-containing group that has only one bond. The bond may be possessed by an element other than carbon. Even if the valence is not specifically stated, a person skilled in the art would be able to ascertain the appropriate valence from the context.
• hydrocarbon group refers to a group containing carbon and hydrogen, from which at least one hydrogen atom has been removed.
• hydrocarbon groups include, but are not limited to, hydrocarbon groups having 1 to 20 carbon atoms, which may be substituted with one or more substituents, such as aliphatic hydrocarbon groups and aromatic hydrocarbon groups.
• substituents such as aliphatic hydrocarbon groups and aromatic hydrocarbon groups.
• the above-mentioned “aliphatic hydrocarbon group” may be linear, branched, or cyclic, and may be saturated or unsaturated.
• the hydrocarbon group may contain one or more ring structures.
• the hydrocarbon group may have one or more heteroatoms or structures containing heteroatoms, such as nitrogen atoms (N), oxygen atoms (O), sulfur atoms (S), phosphorus atoms (P), silicon atoms (Si), amide bonds, sulfonyl bonds, siloxane bonds, carbonyl groups, and carbonyloxy groups, at its terminals or in the molecular chain.
• heteroatoms or structures containing heteroatoms such as nitrogen atoms (N), oxygen atoms (O), sulfur atoms (S), phosphorus atoms (P), silicon atoms (Si), amide bonds, sulfonyl bonds, siloxane bonds, carbonyl groups, and carbonyloxy groups, at its terminals or in the molecular chain.
• substituents for a "hydrocarbon group” include, but are not limited to, halogen atoms; and groups selected from a C 1-6 alkyl group, a C 2-6 alkenyl group, a C 2-6 alkynyl group, a C 3-10 cycloalkyl group, a C 3-10 unsaturated cycloalkyl group, a 5-10 membered heterocyclyl group, a 5-10 membered unsaturated heterocyclyl group, a C 6-10 aryl group, and a 5-10 membered heteroaryl group, each of which may be substituted by one or more halogen atoms.
• alkyl and phenyl groups may be unsubstituted or substituted unless otherwise specified.
• the substituents on such groups are not particularly limited, but may include, for example, one or more groups selected from a halogen atom, a C 1-6 alkyl group, a C 2-6 alkenyl group, and a C 2-6 alkynyl group.
• the curable polyorganosiloxane composition of the present invention contains at least one polyorganosiloxane having two or more hydroxyl groups or hydrolyzable groups bonded to silicon atoms in one molecule as component (A).
• Component (A) functions as a base polymer of the curable polyorganosiloxane composition.
• the hydroxyl group or hydrolyzable group can be present at any position of the polyorganosiloxane molecule.
• the hydroxyl group or hydrolyzable group may be present at the molecular end, or may be present as a side chain at a site other than the end.
• the molecular main chain of component (A) refers to the relatively longest bond chain in the molecule of component (A).
• hydrolyzable group refers to a group that can undergo hydrolysis, that is, a group that can be detached from the main skeleton of a compound by hydrolysis.
• R' examples include unsubstituted alkyl groups such as methyl, ethyl, propyl, isopropyl, n-butyl, and isobutyl; and substituted alkyl groups such as chloromethyl.
• alkyl groups, particularly unsubstituted alkyl groups, are preferred, and methyl or ethyl groups are more preferred.
• the hydroxyl group is not particularly limited, and may be one that is generated by hydrolysis of a hydrolyzable group.
• halogen atoms include fluorine, chlorine, bromine, and iodine atoms, and among these, chlorine atoms are preferred.
• the molecular skeleton of component (A) is not particularly limited as long as the siloxane bond is the main skeleton.
• the siloxane skeleton may be interrupted by a divalent organic group.
• the structural units of the siloxane compound may be described by the following abbreviations. Hereinafter, these structural units may be referred to as "M units", “D units”, etc.
• the siloxane compound is constructed by combining the above structural units, but may at least partially contain the above structural units in which the methyl group is replaced with another group, such as a halogen such as fluorine, or a hydrocarbon group such as a phenyl group.
• the D unit replaced with a phenyl group may be written as D Ph .
• each unit may be arranged arbitrarily, and may contain a structural unit represented by SiPh 2 O 2/2 (written as D Ph2 ).
• the siloxane compound can have various three-dimensional structures due to the T unit or Q unit, but the component (A) can have a linear molecular skeleton formed by arbitrarily combining the above M and D units.
• component (A) is not particularly limited as long as it has, on average, two or more hydroxyl groups or hydrolyzable groups bonded to silicon atoms in one molecule and can form a network structure by a condensation reaction with the -OR 2 group of (B) described below.
• Representative examples of component (A) include those represented by the general formula (1): (R a ) s (R 3 ) t SiO (4-s-t)/2 (1) (Wherein, R a is a hydroxyl group or a hydrolyzable group; R3 is a monovalent hydrocarbon group having no aliphatic unsaturated bonds; s is an integer from 1 to 3; t is an integer from 0 to 2, provided that s+t is 1 to 3.
• the molecule has at least two units represented by the following formula:
• a specific example of the component (A) is a compound represented by the following general formula (2): (R a ) 3-p R p Si-O-(Si(R) r (R a ) 2-r O) n -SiR q (R a ) 3-q ...(2) (Wherein, Each R a is independently a hydroxyl group or a hydrolyzable group; Each R is independently a monovalent organic group, p and q are each independently 0, 1 or 2; Each r is independently 0, 1, or 2; n is a number that provides a viscosity of 0.1 to 500 Pa s at 23°C. Examples of the linear polyorganosiloxane are represented by the formula (2).
• R preferably has a hydrocarbon group, particularly an alkyl group, an alkenyl group, or an aryl group. From the viewpoint of controlling physical properties such as refractive index, at least a part of R may be an aryl group such as a phenyl group. Polyorganosiloxanes in which all R are methyl are particularly preferably used because of their ease of availability. With regard to the position of the curable functional group, polyorganosiloxanes in which r is 2 in the above formula (2), that is, linear polyorganosiloxanes in which at least one curable functional group exists only at both ends of the molecule, are preferred.
• Such component (A) examples include linear polyorganosiloxanes in which both ends are capped with R a 3-m R 3 m SiO 1/2 units and the intermediate units are R 3 2 SiO 2/2 units (wherein R a is a hydroxyl group or a hydrolyzable group, R 3 is a monovalent hydrocarbon group, and m is 0, 1, or 2).
• polyorganosiloxane having a hydroxyl group or a hydrolyzable group bonded to a silicon atom it is preferable that p and q in the above formula (2) are 0 or 1, that is, that the polyorganosiloxane has two or more hydroxyl groups or hydrolyzable groups at each molecular end.
• Such polyorganosiloxanes that can be used as component (A) can be commercially available products. Polyorganosiloxanes into which hydroxyl groups or hydrolyzable groups have been introduced by known reactions can also be used.
• component (A) only one type of compound can be used, or two or more types of compounds can be mixed and used, classified according to the position or type of the substituent, the degree of polymerization, etc.
• component (A) is a polyorganosiloxane, it may be a mixture of polyorganosiloxanes having various degrees of polymerization.
• the amount of component (A) is not particularly limited, so long as it is an amount that results in a handleable viscosity range for the curable polyorganosiloxane composition. Based on the amount of component (A), the amounts of the other components can be appropriately set within the preferred ranges shown below.
• the crosslinking agent in the curable composition of the present invention is a compound having at least two -OR2 groups bonded to a Si atom or a partial hydrolysis condensate thereof (hereinafter also referred to as "crosslinking agent”), and is a compound that undergoes a crosslinking reaction (condensation reaction) with component (A), specifically, with a hydroxyl group or a hydrolyzable group bonded to a Si atom of component (A).
• R2 is independently a hydrogen atom or a monovalent organic group in each occurrence, and is preferably a monovalent organic group.
• the monovalent organic group means a group containing a monovalent carbon.
• Such a monovalent organic group is not particularly limited, but includes a monovalent hydrocarbon group.
• the hydrocarbon group has the same meaning as above.
• the crosslinking agent may or may not have a reactive functional group other than the Si- OR2 group, but from the viewpoint of crosslinking properties, it is preferable that the crosslinking agent does not have any other reactive functional group.
• the other reactive functional group refers to a primary amino group, an epoxy group, a (meth)acryloyl group, a (meth)acryloxy group, a mercapto group, an isocyanato group, etc.
• the crosslinking agent will be described by dividing it into (B1) a crosslinking agent having no reactive functional group and (B2) a crosslinking agent having a reactive functional group.
• crosslinking agent having no reactive functional group is an organosilicon compound represented by R 1 n Si(OR 2 ) 4-n (wherein R 1 is independently in each occurrence a substituted or unsubstituted monovalent hydrocarbon group, R 2 is independently in each occurrence a hydrogen atom or a monovalent organic group, and n is 0, 1, or 2).
• R 1 in each occurrence is independently a substituted or unsubstituted monovalent hydrocarbon group having 1 to 12 carbon atoms.
• R 1 include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, neopentyl, hexyl, heptyl, octyl, nonyl, and decyl; cycloalkyl groups such as cyclopentyl, cyclohexyl, and cycloheptyl; aryl groups such as phenyl, tolyl, xylyl, and naphthyl; aralkyl groups such as benzyl, phenylethyl, and phenylpropyl; alkenyl groups such as vinyl, allyl, propenyl, and butenyl; alkynyl groups such as ethyl groups such as
• n 1 or 2.
• (B1) crosslinking agent having no reactive functional group examples include organosilicon compounds having at least one [Si(XOR g3 )(CH 3 )O] unit and optionally one [Si(R g4 )(CH 3 )O] unit, with these units bonded in a ring.
• organosilicon compounds having at least one [Si(XOR g3 )(CH 3 )O] unit and optionally one [Si(R g4 )(CH 3 )O] unit, with these units bonded in a ring.
• the order of arrangement of the unit containing OR g3 and the unit containing R g4 may be arbitrary, such as alternating between the two.
• R g3 is a monovalent organic group. Specific examples of R g3 include an alkyl group having 1 to 12 carbon atoms, preferably 1 to 4 carbon atoms, and a group represented by -Si(OR") 3-wR " w (wherein R" is an alkyl group having 1 to 4 carbon atoms, and w is an integer of 0 to 3).
• R g3 More specific examples of R g3 include alkyl groups such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, and a tert-butyl group, a trimethoxysilyl group, a triethoxysilyl group, a dimethoxymethylsilyl group, and a diethoxyethylsilyl group.
• X is a single bond or a divalent alkylene group having 1 to 12 carbon atoms.
• R g4 is independently in each occurrence a monovalent organic group.
• R g4 is preferably a substituted or unsubstituted monovalent hydrocarbon group, more preferably a substituted or unsubstituted monovalent hydrocarbon group having 1 to 12 carbon atoms.
• R g4 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 pentyl group, a neopentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, and a decyl group; cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group, and a cycloheptyl group; aryl groups such as a phenyl group, a tolyl group, a xylyl group, and a naphthyl group; aralkyl groups such as a benzyl group, a phenylethyl group, and a phenylpropyl group; alkenyl group
• the number of [Si(XOR g3 )(CH 3 )O] units contained in one molecule is at least 1, and preferably 4 or less.
• the number of [Si(R g4 )(CH 3 )O] units may be 0, but when the number of [Si(XOR g3 )(CH 3 )O] units is 1, the number is 1 or more.
• the total number of [Si(XOR g3 )(CH 3 )O] units and [Si(R g4 )(CH 3 )O] units contained in one molecule is preferably 2 or more and 4 or less.
• the crosslinking agent having no reactive functional group is a compound represented by the formula R 1 n Si(OR 2 ) 4-n (wherein R 1 , R 2 and n are as defined above).
• the crosslinking agent (B1) having no reactive functional group is an alkoxy group-containing compound such as tetramethoxysilane, methyltrimethoxysilane, vinyltrimethoxysilane, decyltrimethoxysilane, phenyltrimethoxysilane, tetraethoxysilane, methyltriethoxysilane, vinyltriethoxysilane, phenyltriethoxysilane, tetrapropoxysilane, tetraisopropoxysilane, dimethyldimethoxysilane, vinylmethyldimethoxysilane, dimethyldiethoxysilane, diphenyldimethoxysilane, and 3-chloropropyltrimethoxysilane, and partial hydrolysis condensates thereof; tetrakis(2-ethoxy)silane; substituted alkoxy group-containing compounds such as methyltripropenoxysilane, methyltri
• the crosslinking agent having a reactive functional group (B2) is a compound that not only contributes to the crosslinking reaction (condensation reaction) with the component (A) but also functions as an adhesion imparting agent.
• Compounds represented by the following formula can be used.
• R g3 and R g4 have the same meanings as defined above.
• R g6 independently represents R g8 -R g7 - at each occurrence.
• R g7 in each occurrence, independently represents a single bond, an oxygen atom, or a divalent organic group.
• the divalent organic group is as defined above.
• R g7 is preferably an alkylene group having 1 to 10 carbon atoms, or a group having 1 to 10 carbon atoms and containing a nitrogen atom or an oxygen atom in the main chain.
• R g7 is more preferably an alkylene group having 1 to 3 carbon atoms, CH2CH2 - NH-CH2CH2CH2 , or CH2 - O - CH2CH2CH2 .
• R g8 is a reactive functional group.
• R g8 is preferably, independently in each occurrence, a primary amino group, an epoxy group, a (meth)acryloyl group, a (meth)acryloxy group, a mercapto group, or an isocyanato group, and more preferably a primary amino group.
• ⁇ 4 is 2 or 3, more preferably 3.
• ⁇ 5 is 0 or 1.
• ⁇ 6 is 1 or 2, preferably 1.
• the sum of ⁇ 4, ⁇ 5 and ⁇ 6 is 4. It is particularly preferable that ⁇ 4 is 3, ⁇ 5 is 0 and ⁇ 6 is 1.
• crosslinking agents having reactive functional groups include substituted or unsubstituted amino group-containing silanes such as 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyltriisopropoxysilane, 3-aminopropyltriacetamidosilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltriethoxysilane, N-methyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, and N,N-dimethyl-3-aminopropyltrimethoxysilane; 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyld
• the crosslinking agent may be used alone or in combination of two or more kinds. When two or more kinds are used in combination, it may be a combination of two or more kinds of (B1), a combination of two or more kinds of (B2), or a combination of one or more kinds of each of (B1) and (B2). From the viewpoint of crosslinking properties, it is preferable that the crosslinking agent (b) contains at least one kind of (B1).
• the crosslinking agent contains two or more kinds of alkoxysilanes represented by the formula: R 1 n Si(OR 2 ) 4-n , it is preferable to use two kinds having different values of n in the above formula in combination, and in this case, it is preferable that the smaller the value of n, the smaller the number of carbon atoms of R 1 and R 2.
• a tetrafunctional alkoxysilane having a value of n of 0 and a trifunctional alkoxysilane having a value of n of 1 it is preferable that at least one of R 1 and R 2 of the trifunctional alkoxysilane has a smaller carbon number than the carbon number of R 1 and R 2 of the tetrafunctional alkoxysilane, and it is preferable that the carbon numbers of both R 1 and R 2 of the functional alkoxysilane are smaller than the carbon numbers of R 1 and R 2 of the tetrafunctional alkoxysilane.
• the crosslinking agent may be contained in the curable composition in an amount of, for example, 0.1 parts by mass or more, specifically 0.3 parts by mass or more, and 30 parts by mass or less, specifically 20 parts by mass or less, and more specifically 10 parts by mass or less, per 100 parts by mass of component (A).
• the crosslinking agent may be contained in the curable composition in an amount of, for example, 0.1 to 30 parts by mass, specifically 0.3 to 10 parts by mass, and more specifically 0.3 to 5.0 parts by mass, per 100 parts by mass of component (A).
• the crosslinking agent may contain, for example, 1 mole or more, specifically 2 moles or more of -OR2 groups per mole of hydroxyl groups or hydrolyzable groups bonded to Si atoms of component (A) in the curable composition.
• the crosslinking agent may contain, for example, 30 moles or less, specifically 20 moles or less, and more specifically 10 moles or less of -OR2 groups per mole of hydroxyl groups or hydrolyzable groups bonded to Si atoms of component (A).
• the crosslinking agent can contain -OR2 groups in an amount, for example, in the range of 1 to 30 moles, specifically, in the range of 2 to 20 moles, per mole of hydroxyl groups or hydrolyzable groups bonded to Si atoms in component (A).
• the (C) condensation catalyst is a component that promotes hydrolysis and condensation between the above-mentioned component (A) and the above-mentioned crosslinking agent.
• a metal catalyst an organic acid catalyst, an inorganic acid catalyst, a base catalyst, etc. can be used. From the viewpoint of the curing speed of the composition, the condensation catalyst is preferably a metal catalyst.
• metal atoms contained in the metal catalyst include titanium, zirconium, and tin.
• organotin compounds or alkoxytitaniums are preferred.
• a compound having an alkoxide (-O-R h ) as a ligand can be used.
• the R h is preferably an alkyl group having 1 to 4 carbon atoms.
• the condensation reaction is further promoted.
• the R h is more preferably an alkyl group having 1 to 3 carbon atoms.
• the condensation reaction is particularly promoted.
• the catalyst is easily dissolved or dispersed in the curable composition, and can contribute to promoting a uniform reaction. The catalyst is less likely to contain foreign matter, and can contribute to the formation of a transparent cured product of the curable composition.
• Preferred metal catalysts include metal carboxylates such as iron octoate, manganese octoate, zinc octoate, tin naphthate, tin caprylate, and tin oleate; organic tin compounds such as dibutyltin diacetate, dibutyltin dioctoate, dibutyltin dilaurate, dibutyltin dioleate, diphenyltin diacetate, dibutyltin oxide, dibutyltin dimethoxide, dibutylbis(triethoxysiloxy)tin, dioctyltin dilaurate, and dimethyltin dineodecanoate; tetraethoxytitanium, tetrapropoxytitanium, tetraisopropoxytitanium, tetra-n-butoxytitanium, tetraisobutoxytitanium, and diisoprop
• organic titanium compounds such as 1,3-propanedioxytitanium bis(ethylacetoacetate) and 1,3-propanedioxytitanium bis(ethylacetoacetate); organic aluminum compounds such as aluminum trisacetylacetonate, aluminum trisethylacetoacetate, diisopropoxyaluminum ethylacetoacetate, and triethoxyaluminum; and organic zirconium compounds such as zirconium tetraacetylacetonate, tetraisopropoxyzirconium, tetrapropoxyzirconium, tetra-n-butoxyzirconium, tetraisobutoxyzirconium, tributoxyzirconium acetylacetonate, and tributoxyzirconium stearate.
• organic titanium compounds such as 1,3-propanedioxytitanium bis(ethylacetoacetate) and 1,3-propanedioxy
• organic acid catalyst examples include compounds having carboxylic acid, sulfonic acid, and phosphoric acid, and specific examples include acetic acid, trifluoroacetic acid, methanesulfonic acid, toluenesulfonic acid, and alkyl phosphoric acid.
• Examples of the inorganic acid catalyst include hydrochloric acid and sulfuric acid.
• the base catalyst examples include amine compounds such as ammonia, triethylamine, and diethylamine, dialkylhydroxylamines such as dimethylhydroxylamine and diethylhydroxylamine, and guanidyl compounds such as tetramethylguanidine and guanidyl group-containing silanes or siloxanes.
• amine compounds such as ammonia, triethylamine, and diethylamine
• dialkylhydroxylamines such as dimethylhydroxylamine and diethylhydroxylamine
• guanidyl compounds such as tetramethylguanidine and guanidyl group-containing silanes or siloxanes.
• the condensation catalyst is preferably contained in the curable composition of the present invention in an amount of 0.01 to 10.0 parts by mass, and more preferably 0.03 to 5.0 parts by mass, per 100 parts by mass of component (A). Only one type of condensation catalyst may be used, or two or more types may be used simultaneously.
• composition of the present invention contains a specific adhesion promoter, specifically, a silicon-based adhesion promoter which is a compound having in one molecule at least one adhesion-imparting functional group selected from a linear, branched or cyclic aliphatic unsaturated hydrocarbon group, an epoxy group, an alkoxy group bonded to a silicon atom, and a hydrogen atom bonded to a silicon atom, and which has in one molecule at least one heteroatom other than the adhesion-imparting functional group (excluding those falling under (A) or (B)).
• a specific adhesion promoter specifically, a silicon-based adhesion promoter which is a compound having in one molecule at least one adhesion-imparting functional group selected from a linear, branched or cyclic aliphatic unsaturated hydrocarbon group, an epoxy group, an alkoxy group bonded to a silicon atom, and a hydrogen atom bonded to a silicon atom, and which has in one molecule at least one
• the simplest structure of such compounds corresponding to component (D) is a compound in which the above-mentioned adhesive functional group is bonded to a functional group having a hetero atom.
• examples of such compounds include 3-acryloxypropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-acryloxypropylmethyldimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, and 3-methacryloxypropylmethyldiethoxysilane.
• a structure in which an adhesive functional group is bonded to the structure of the organic molecule that is the main skeleton of the compound via a spacer group is a preferred structure.
• a heteroatom is present other than the main skeleton of the compound, that is, if there is a reactive group of the heteroatom at the end of the molecule, it may couple with a condensation catalyst and affect the curing property, resulting in poor curing. Therefore, a structure in which an adhesive functional group is bonded via a spacer group in the molecular chain is preferred.
• the main skeleton of the compound corresponding to component (D) it is preferable to use a polyhydric alcohol, an aromatic compound, or a heterocyclic compound, since it is possible to introduce a plurality of adhesiveness-imparting functional groups, and it is easy to design that they occupy an equivalent positional relationship in the geometric structure of the molecule.
• the structure that can be adopted as the main skeleton the following are preferred examples, since the raw materials are easily available.
• the spacer group is a portion that connects the adhesiveness-imparting functional group and the main skeleton.
• the location of the spacer group in the skeleton is not particularly limited as long as it is in the middle of the molecular chain other than the terminal. It is preferable that a heteroatom is present in the skeleton of this spacer group.
• a divalent alkylene group in which at least one position is replaced with a heteroatom is cited as a preferred example because it is easy to design.
• a spacer group that does not have a heteroatom for example, a divalent alkylene group such as ethylene (-CH 2 -), may be used.
• the divalent alkylene group preferably has 1 to 20 carbon atoms, more preferably has 1 to 12 carbon atoms, and even more preferably has 1 to 8 carbon atoms.
• the spacer group may have any structure of a straight chain, a branched chain, or a cyclic structure.
• Heteroatoms include oxygen (O), nitrogen (N), sulfur (S) and phosphorus (P). These heteroatoms may be contained as structures such as carbonyl, thiocarbonyl and imine. These heteroatoms are preferably contained as ether structures, thioether structures, amine or phosphine structures.
• the compound composed of heteroatoms as component (D) is preferably at least one selected from the group consisting of sulfur compounds, nitrogen compounds and phosphorus compounds. It is more preferable to have at least one sulfur atom in order to further improve adhesion. When heteroatoms are present in the spacer group, there are no particular limitations on their positional relationship.
• Component (D) has at least one adhesion-imparting functional group selected from a linear, branched or cyclic aliphatic unsaturated hydrocarbon group, an epoxy group, an alkoxy group bonded to a silicon atom, and a hydrogen atom bonded to a silicon atom.
• one adhesion-imparting functional group is sufficient to contribute to the impartation of adhesion, it is preferable to have two or more adhesion-imparting functional groups per molecule. It is preferable to have an epoxy group or an alkoxy group bonded to a silicon atom.
• Component (D) is more preferably an organosilicon compound having at least one SiR 5 3-n (OR 5 ) n group (wherein R 5 is a monovalent hydrocarbon group having no aliphatic unsaturated bond, and n is 1, 2 or 3). In this case, it is particularly preferable that R 5 is a methyl group or an ethyl group.
• component (D) is an alkoxysilyl compound having the above group, its partial hydrolysis condensate is also preferable as component (D).
• component (D) may have any organic group.
• component (D) may further have one or more groups selected from the group consisting of an aromatic hydrocarbon-containing group, an epoxy group-containing group, and an aliphatic unsaturated hydrocarbon group.
• Specific examples of component (D) include the following compounds, but are not limited thereto as long as they satisfy the above requirements.
• the content of component (D) is in the range of 0.05 to 20 parts by mass per 100 parts by mass of component (A). By using this range, higher adhesion to the substrate can be achieved. By using 0.05 parts by mass or more, sufficient adhesion can be achieved. Furthermore, by using 20 parts by mass or less, the concentration of components (A) and (B) in the composition can be kept at an appropriate level, the effect of increasing adhesion can be easily achieved, and the resinification of the surface and the occurrence of cracks can be suppressed, resulting in a more sufficient cured state.
• a more preferred content range is 0.1 to 15 parts by mass, and even more preferred is a range of 0.5 to 10 parts by mass.
• the composition of the present invention further comprises an inorganic filler to suppress the fluidity of the composition.
• the inorganic filler includes reinforcing fillers such as fumed titanium oxide; oxides such as silica, diatomaceous earth, iron oxide, zinc oxide, titanium oxide, and aluminum oxide; carbonates such as calcium carbonate, magnesium carbonate, and zinc carbonate; silicates such as aluminosilicate, calcium silicate, and mica; talc; conductive fillers such as carbon black, copper powder, and nickel powder; and those whose surfaces are treated with a hydrophobizing agent.
• the inorganic filler is preferably silica, surface-treated silica, carbon black, or calcium carbonate, and more preferably silica or surface-treated silica.
• the curable composition of the present invention contains surface-treated silica as an inorganic filler.
• surface-treated silica the fluidity of the composition can be suppressed and mechanical strength can be imparted to the cured product of the composition.
• surface treatment refers to the use of a compound that is reactive with the silanol groups on the silica surface to covalently bond the silanol groups to other groups.
• silica examples include fumed silica, calcined silica, silica aerogel, precipitated silica, and pulverized silica.
• fumed silica is preferred because it suppresses the fluidity of the composition with a small amount of compounding and imparts mechanical strength to the cured product of the composition.
• the surface-treated silica preferably has a BET specific surface area of 50 to 500 m 2 /g, more preferably 80 to 400 m 2 /g, and even more preferably 100 to 300 m 2 /g.
• Surface treatment methods include silazane compounds (hexamethyldisilazane, 1,3-divinyl-1,1,3,3-tetramethyldisilazane, 1,3-bis(chloromethyl)tetramethyldisilazane, 1,3-bis(3,3,3-trifluoropropyl)-1,1,3,3-tetramethyldisilazane, 1,3-diphenyltetramethyldisilazane, heptamethyldisilazane, 2,2,4,4,6,6-hexamethylcyclotrisilazane, octamethylcyclotetrasilazane, 1,1,3,3-tetramethyldisilazane, 2,4,6-trimethyl-2,4,6-trivinylcyclotrisilazane, etc.), alkoxysilane compounds (methyltrimethyldisilazane, ...
• Examples of the treatment include treatment with silane, dimethyldimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, octyltrimethoxysilane, octyltriethoxysilane, decyltrimethoxysilane, hexadecyltrimethoxysilane, etc.), chlorosilane compounds (methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, etc.), octamethylcyclotetrasiloxane, dimethylsiloxane oligomers, etc.
• silica surface can be hydrophobized with a small amount of treatment.
• hexamethyldisilazane and dimethyldichlorosilane are preferred.
• hexamethyldisilazane is preferred from the viewpoints of the degree of treatment and the stability (inactivation) of the surface state after treatment.
• These surface treatment agents may be mixed with silica during preparation of the curable composition and kneaded to treat the surface of the silica. Commercially available materials may also be used.
• the inorganic filler preferably has a primary particle diameter of 0.01 to 0.1 ⁇ m. By setting the primary particle diameter of the inorganic filler within the above range, a composition with reduced fluidity can be obtained.
• the primary particle diameter of the inorganic filler is preferably 0.02 to 0.08 ⁇ m, and more preferably 0.03 to 0.07 ⁇ m. The primary particle diameter is measured by electron microscopy.
• the amount of inorganic filler to be used may be such that the shape of the curable composition is maintained after application, and is preferably adjusted appropriately within that range.
• the inorganic filler is preferably contained in an amount of 1 to 500 parts by mass, more preferably 1 to 200 parts by mass, and even more preferably 1 to 100 parts by mass, per 100 parts by mass of component (A).
• only one type of inorganic filler may be used, or two or more types may be used simultaneously.
• the curable polyorganosiloxane of the present invention contains the above-mentioned components (A) to (E).
• the polyorganosiloxane composition of the present invention is not particularly limited in its properties, so long as each component is uniformly mixed and has a degree of fluidity that allows application to a substrate.
• the viscosity can be adjusted appropriately using the resin and solvent described below.
• the polyorganosiloxane composition can be a one-part type composition in which all components are mixed together, or a two-part type composition in which component (B) and component (C) are separately blended.
• component (B) and component (C) are separately blended.
• the choice of whether to use a one-part or two-part composition can be made appropriately, taking into consideration workability, curing conditions, etc., and the method is well known to those skilled in the art.
• the curable polyorganosiloxane composition of the present invention can be blended with other known components, so long as they do not impair the purpose and effect of the composition.
• additives flame retardants, adhesion promoters other than (D), heat resistance promoters, diluents, organic solvents, inorganic or organic pigments, etc.
• siloxane resins that do not fall under the above-mentioned components (A) and (B) can also be blended. Examples of such resins include polyorganosiloxanes having only one curable functional group, and polyorganosiloxanes having no curable functional groups such as dimethylsiloxane. These resins can be used as diluents.
• the curable polyorganosiloxane composition may further contain a siloxane resin that does not fall under the component (A) or (B).
• a resin can also be used as a diluent for adjusting viscosity.
• a siloxane resin is a resin obtained by combining the M, D, T, and Q units, which does not have a hydroxyl group or a hydrolyzable group or has only one of them, particularly the following formula: (R a ) 3-p R p Si-O-(SiR 2 O) n -SiR 3 (In the formula, R a , R, p, and n are as defined in general formula (2)).
• siloxanes having only one hydroxyl group or hydrolyzable group such as those represented by the following formula: R 3 Si-O-(SiR 2 O) n -SiR 3 (In the formula, R and n are as defined in general formula (2)). It is possible to use a siloxane having no hydroxyl group or hydrolyzable group, which is represented by the following formula: By using such a siloxane resin, it is possible to control the hardness when the curable polyorganosiloxane composition is cured, and to control the viscosity of the composition, and it is possible to widely respond to the handling properties and required physical properties.
• the curable polyorganosiloxane composition may contain, for example, 50 parts by mass or less, specifically 0.1 to 50 parts by mass, and more specifically 1 to 30 parts by mass of such a resin per 100 parts by mass of component (A).
• the curable polyorganosiloxane composition may further contain an adhesion promoter other than (D).
• the adhesion promoter is a component that improves the adhesion of the cured product of the composition to substrates such as glass, metal, and plastic.
• adhesion promoters include metal alkoxides, compounds having a hydrolyzable silyl group, compounds having a hydrolyzable silyl group and a reactive organic functional group in one molecule, compounds having a hydrogen atom bonded to a silicon atom and a divalent aromatic group in one molecule, compounds having a hydrogen atom bonded to a silicon atom and a reactive organic functional group in one molecule, and/or partial hydrolysis condensates thereof (excluding those corresponding to (D)).
• metal alkoxides examples include aluminum alkoxides such as aluminum triethoxide, aluminum tripropoxide, and aluminum tributoxide; titanium alkoxides such as titanium tetraethoxide, titanium tetrapropoxide, titanium tetraisopropoxide, titanium tetrabutoxide, titanium tetraisobutoxide, and titanium tetraisopropenyl oxide.
• organic compound adhesion promoters include amino group-containing silanes, isocyanurates, and carbasilatrane compounds.
• tetraethoxysilane examples include tetraethoxysilane, tetramethoxysilane oligomers, vinyltrimethoxysilane, vinyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, and 3,4-epoxycyclohexylethyltrimethoxysilane.
• adhesion promoters include organosilicon compounds having a Si(OR 4 ) n group (wherein R 4 represents an alkyl group having 1 to 4 carbon atoms or a 2-methoxyethyl group; n is an integer from 1 to 4) and, when n is 1 to 3, an epoxy group-containing group, and/or a partial hydrolysis condensate thereof.
• adhesion promoters other than (D) include aluminum alkoxides such as aluminum triethoxide, aluminum tripropoxide, and aluminum tributoxide; titanium alkoxides such as titanium tetraethoxide, titanium tetrapropoxide, titanium tetraisopropoxide, titanium tetrabutoxide, titanium tetraisobutoxide, and titanium tetraisopropenyl oxide; zirconium acylates such as zirconium octanoate, zirconium tetra(2-ethylhexanoate), and zirconium stearate; zirconium alkoxides such as n-propyl zirconate and n-butyl zirconate (excluding zirconium chelates); and metal alkoxides such as tributoxy zirconium acetylacetonate, dibutoxy zirconium bis(ethylacetoacetate), zir
• the additional adhesion promoter may be contained in the curable polyorganosiloxane composition in an amount of, for example, 10 parts by mass or less, specifically, 0.01 to 10 parts by mass, and more specifically, 0.1 to 5 parts by mass, per 100 parts by mass of component (A).
• One type of adhesion promoter may be used alone, or two or more types may be used in combination.
• the curable polyorganosiloxane composition may contain a solvent.
• the curable polyorganosiloxane composition may be dissolved in a suitable solvent at a desired concentration depending on its application and purpose.
• the concentration of the solvent may be, for example, 80 parts by mass or less, 50 parts by mass or less, 30 parts by mass or less, or 20 parts by mass or less, relative to 100 parts by mass of the composition.
• One aspect of the present invention is an adhesive comprising the curable polyorganosiloxane composition.
• the cured product of the composition and various substrates need only have an adhesive portion, and the shape of the adhesive portion is not limited.
• one aspect of a method for producing an article comprising an adhesive portion between a substrate and a cured product of the composition comprises the steps of preparing a component comprising a substrate and a composition; applying the composition to the surface of the substrate; and curing the composition to adhere the substrate and the cured product of the composition.
• substrates examples include metals such as aluminum, copper, nickel, iron, steel, brass, and stainless steel; engineering plastics such as epoxy resins, polyester resins such as polyethylene terephthalate and polybutylene terephthalate (PBT) resins, polycarbonate resins, acrylic resins, polyimide resins, phenolic resins, polyamide resins, polyphenylene sulfide (PPS) resins, and modified polyphenylene ether (PPE) resins; and glass. If necessary, the walls of the gaps may be treated with a primer in the usual manner. There are no particular limitations on the shape or thickness of the substrate.
• the adhesive containing the curable polyorganosiloxane composition is applied to the surface of the part including the substrate at a predetermined thickness to the area to be bonded by a method such as dripping, injection, casting, extrusion from a container, coating such as bar coating or roll coating, screen printing, dipping, brushing, spraying, or dispensing. These methods are known to those skilled in the art.
• the composition may be applied entirely and uniformly on the surface of the part, or may be applied unevenly or partially, such as in lines, stripes, or dots.
• the application thickness of the composition is usually 0.01 to 3 mm, and preferably 0.05 to 2 mm.
• the composition can be attached to the object to be bonded by injection, dripping, casting, pouring, extrusion from a container, or by integral molding using transfer molding or injection molding, and then left at room temperature (e.g., 23°C) to harden, thereby simultaneously adhering to the object to be bonded.
• the hardening time is preferably one week or less, more preferably 72 hours or less, and particularly preferably 24 hours or less from the viewpoint of production.
• Articles using the curable polyorganosiloxane composition of the present invention as an adhesive have excellent durability, including water resistance and oil resistance of the adhesive surface, making it possible to meet the demand for bonding metals such as aluminum and aluminum die cast, and engineering plastics such as PBT and PET with silicone. Such articles can be used particularly well as various parts in aircraft, automotive applications, and the electronic materials field.
• composition of the present invention will be described in more detail through the following examples, but the present invention is not limited to the embodiments of these examples.
• compound 1 is a compound having the following structure.
• Compound 1 was synthesized as follows. 74.5 g of triallyl isocyanurate, 98 g of 3-mercaptopropyltrimethoxysilane, and 200 g of toluene were added in this order to a 500 mL separable flask, and the mixture was stirred at room temperature for 10 minutes. 0.5 g of AIBN (azobisisobutyronitrile) was added, and the mixture was stirred at room temperature for 10 minutes under a nitrogen atmosphere.
• AIBN azobisisobutyronitrile
• moisture-curable silicone compositions were prepared according to the procedure of Example 1, except that the compound corresponding to (D) was not added (Comparative Example 1), 0.5 parts by mass of 1,3,5-tris(trimethoxysilylpropyl)isocyanurate was added instead of the compound corresponding to (D) (Comparative Example 2), and the amount of compound 1 was 20.41 parts by mass (Comparative Example 3).
• moisture-curable silicone compositions of the comparative examples were prepared according to the procedure of Example 1, except that the compound corresponding to (D) was not added (Comparative Example 1), 0.5 parts by mass of 1,3,5-tris(trimethoxysilylpropyl)isocyanurate was added instead of the compound corresponding to (D) (Comparative Example 2), and the amount of compound 1 was 20.41 parts by mass (Comparative Example 3).
• Compound 2 has the following structure. Compound 2 was obtained by adjusting the amount of the raw materials in the same manner as compound 1.
• Compound 3 was obtained by changing the number of epoxy groups from compound 1 in a similar manner.
• Compounds 4 to 8 were obtained in the same manner by changing the main skeleton substance from compound 1.
• the structures of each compound are as follows:
• the polyorganosiloxane composition was dispensed and molded into a 2 mm sheet, and then left to cure for 7 days in an atmosphere of 23°C and 50% RH to obtain a cured product of the polyorganosiloxane composition.
• the hardness (initial hardness) of the obtained cured product was measured using a type A hardness tester.
• the tensile strength was measured according to JIS K 6249.
• the elongation was measured according to JIS K6249.
• the polyorganosiloxane composition was applied to the surface of an aluminum petri dish having a diameter of 5 cm, the surface of which had been cleaned with an organic solvent, and the time required for the surface to be confirmed as dry when touched with a finger in an environment of 23° C. and a relative humidity of 50% (RH) was measured.
• ⁇ Shear adhesive strength> The following method was used to evaluate the shear adhesive strength.
• the silicone composition was applied to one end of the test piece and spread evenly, and then the other end of the test piece was attached to the silicone composition so that the adhesive surface was 25 mm in the width direction and 10 mm in the length direction to obtain a test piece.
• the test piece was placed in an oven adjusted to the temperature of the curing conditions while being fixed with a jig, and cured for the time period of the curing conditions. After the temperature of the test piece returned to room temperature (23°C), the prepared test piece was measured with a tensile tester at a tensile speed of 10 mm/min, and the "tensile shear adhesive strength" (MPa) was obtained.
• MPa tensile shear adhesive strength
• the cohesive failure rate is the rate at which the silicone layer is broken without peeling at the interface of the opposing adherends in the shear bond strength test. A cohesive failure rate of 100% indicates that the adhesive strength (adhesion) is sufficiently maintained. After measuring the shear bond strength according to the description of "shear bond strength" above, the area of the silicone layer adhered to each adherend was divided by the coating area to obtain the cohesive failure rate (area%). Details of the test are in accordance with JIS K 6249.
• ⁇ Test 1 Water resistance test> Regarding the shear bond strength and cohesive failure rate related to adhesive force, the compositions of the examples and comparative examples were applied to glass, aluminum, copper, and PPS, and the shear bond strength and cohesive failure rate were measured immediately after application (0:00). The samples were then immersed in 70°C water or a 50°C sodium chloride aqueous solution (salt water), and similar measurements were made after 7 days and after 14 days in the case of 70°C water. These evaluation results are summarized in Tables 2 to 6.
• ⁇ Test 2 Oil resistance test> Using the same method as in Test 1, the compositions of the Examples and Comparative Examples were applied to aluminum and mild steel, and immersed in automobile transmission oil (Autofluid Type T-IV, manufactured by Toyota) in an environment of 120°C. The shear bond strength and cohesive failure rate, which are related to adhesive strength, were measured for the aluminum after 100 hours and 240 hours, and for the mild steel after 100 hours and 14 days. The evaluation results are summarized in Tables 7 and 8.
• Tables 2 to 6 show that in the comparative examples not containing the component (D) specified in the present invention, the adhesive strength and cohesive failure rate for each substrate are significantly reduced by contact with moisture (salt water), whereas the composition of the present invention has high adhesion to all substrates and high water resistance.
• the amount of component (D) it is shown that the composition has high adhesion to all substrates and high water resistance. This tendency is also the same when it comes into contact with oil. Since silicone is compatible with oil, there are concerns about swelling due to oil and deterioration of physical properties and adhesiveness due to additives contained in the oil. However, the composition of the present invention was able to maintain high adhesion even in the presence of oil. Overall, it was shown that the composition of the present invention is also excellent as an adhesive for the internal structure of an automobile, which is likely to come into contact with hot oil.
• the composition of the present invention is a moisture-curable silicone composition that has high adhesiveness and excellent resistance to water, salt water, and oil.
• the present invention provides a moisture-curable silicone composition that has excellent adhesiveness to various substrates that come into frequent contact with moisture or oil.

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