Heat-curable curable composition and its cured product
A heat-curable composition using metal compounds and chelate compounds with polyoxyalkylene polymers addresses the stability and curability trade-off, ensuring stable storage and effective curing when heated, producing high-quality cured products.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2021-06-17
- Publication Date
- 2026-03-13
AI Technical Summary
Hydrolyzable silyl group-containing polyoxyalkylene polymers in curable compositions face a trade-off between storage stability and curability during heating, with insufficient water for curing leading to decreased curability and bubble formation when heated.
Incorporating a metal compound containing aluminum or zinc as a catalyst and a chelate compound as a ligand, along with a chelate compound, into a heat-curable composition with a polyoxyalkylene polymer having hydrolyzable silyl groups, and optionally including an epoxy compound and zeolite-based adsorbent, to maintain storage stability and enhance curability during heating.
The composition achieves good storage stability under sealed conditions and excellent curability when heated, producing high-quality cured products without bubbles.
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Abstract
Description
[Technical Field]
[0001] The present invention relates to a heat-curable composition containing a hydrolyzable silyl group-containing polymer, and a cured product thereof. [Background technology]
[0002] Hydrolyzable silyl group-containing polymers are known as moisture-reactive polymers and are included in many industrial products such as adhesives, sealants, coatings, paints, and tacks, and are used in a wide range of fields.
[0003] Such hydrolyzable silyl group-containing polymers include various polymers with main chain skeletons such as polyoxyalkylene polymers, saturated hydrocarbon polymers, and (meth)acrylic acid ester copolymers. Among these, polyoxyalkylene polymers, such as those described in Patent Document 1, have a wide range of applications due to their relatively low viscosity at room temperature, ease of handling, and the good elasticity of the cured product obtained after the reaction.
[0004] When a curable composition containing such a hydrolyzable silyl group-containing polyoxyalkylene polymer is used, for example, in construction applications, it is common practice to apply the composition to the application site and then allow the curing reaction to proceed by curing it at room temperature for a long period of time.
[0005] However, for industrial applications, it may be necessary to heat the coating after application to cure it quickly. Patent documents 2 and 3 describe heat-curable compositions containing hydrolyzable silyl group-containing polyoxyalkylene polymers. [Prior art documents] [Patent Documents]
[0006] [Patent Document 1] Japanese Patent Application Publication No. 52-73998 [Patent Document 2] International Publication No. 2017 / 111121
Patent Document 3
Summary of the Invention
Problems to be Solved by the Invention
[0007] Generally, in a curable composition containing a hydrolyzable silyl group-containing polyoxyalkylene polymer, in order to ensure the stability during storage, it is known to blend an alkoxysilane-based dehydrating agent such as vinylsilane. However, in the curable composition blended with an alkoxysilane-based dehydrating agent, the alkoxysilane-based dehydrating agent and water react in the system during storage. Therefore, during heat curing in which curing proceeds in a shorter time compared to room temperature curing, the water contributing to the curing reaction becomes insufficient, resulting in a decrease in curability and a problem that bubbles are generated in the cured product. Therefore, when the curable composition is used as a heat-curable type, there is room for improvement in the balance between storage stability and curability during heating.
[0008] In view of the above situation, an object of the present invention is to obtain a heat-curable curable composition that contains a hydrolyzable silyl group-containing polyoxyalkylene polymer, has good storage stability under sealing, and has good curability during heating.
Means for Solving the Problems
[0009] As a result of investigations to solve the above problems, the present inventors have found that by using a metal compound containing at least one metal element selected from the group consisting of (B) aluminum and zinc as a catalyst and a chelate compound as a ligand, and (C) a chelate compound, it is possible to achieve both storage stability under sealing and curability during heating.
[0010] That is, the present invention is: (A) A polyoxyalkylene polymer having a hydrolyzable silyl group represented by the general formula (1), -Si(R1 ) 3-a (X) a (1) (In the formula, R 1 Each of these independently represents a hydrocarbon group having 1 to 20 carbon atoms, and the hydrocarbon group may have a hetero-containing group. Each of these independently represents a hydroxyl group or a hydrolyzable group. a is 1, 2, or 3. (B) Metal compounds comprising at least one metal element selected from the group consisting of aluminum and zinc, and a chelate compound that is a ligand, and (C) Chelate compound, This relates to a heat-curable curable composition containing [specifically, a heat-curable type]. The aforementioned heat-curable composition may further contain an epoxy compound that contains at least two (D) epoxy groups in one molecule. The aforementioned heat-curable composition may further contain a (T) zeolite-based adsorbent. Preferably, the water content of the heat-curable composition is 100 to 500 ppm. Preferably, the chelate compound (C) is a β-dicarbonyl compound, and more preferably, at least one selected from the group consisting of β-diketones and β-ketoesters. Preferably, a in general formula (1) is 3. Preferably, epoxy compound (D) is an alicyclic epoxy compound. Preferably, the content of the metal compound (B) is 0.1 to 10 parts by weight and the content of the chelate compound (C) is 0.1 to 10 parts by weight per 100 parts by weight of the polymer (A). Preferably, the ratio of the total number of moles of the chelate compound and chelate compound (C) in metal compound (B) to the number of moles of the metal element in metal compound (B) is greater than 3. The present invention also relates to a method for producing the heat-curable composition, comprising the step of mixing a polymer (A), a metal compound (B), and a chelate compound (C). The present invention also relates to a cured product obtained by curing the heat-curable curable composition. Furthermore, the present invention relates to a method for producing a cured product, which includes a step of heat-curing the heat-curable composition. Preferably, the manufacturing method further includes a step of storing the heat-curable composition in a sealed container at 23°C to 50°C for 1 day to 4 weeks prior to the heat-curing step. Preferably, the temperature of the heat curing step is 40 to 220°C. [Effects of the Invention]
[0011] According to the present invention, it is possible to provide a heat-curable composition that contains a polyoxyalkylene polymer having a hydrolyzable silyl group, exhibits good storage stability under sealed conditions, and has good curability when heated. [Modes for carrying out the invention]
[0012] Embodiments of the present invention are described in detail below. This embodiment is, (A) Polyoxyalkylene polymer having a hydrolyzable silyl group as shown in general formula (1), -Si(R 1 ) 3-a (X) a (1) (In the formula, R 1 Each of these independently represents a hydrocarbon group having 1 to 20 carbon atoms, and the hydrocarbon group may have a hetero-containing group. Each of these independently represents a hydroxyl group or a hydrolyzable group. a is 1, 2, or 3. (B) Metal compounds comprising at least one metal element selected from the group consisting of aluminum and zinc, and a chelate compound that is a ligand, and (C) Chelate compound, This relates to a heat-curable curable composition containing [specifically, a heat-curable type].
[0013] <<(A) Polyoxyalkylene polymer having hydrolyzable silyl groups as shown in general formula (1)>> The thermosetting curable composition according to this embodiment contains, as a curable resin, (A) a polyoxyalkylene polymer having a hydrolyzable silyl group represented by the general formula (1) (hereinafter also referred to as polymer (A)). -Si(R 1 ) 3-a (X) a (1) (In the formula, R 1 each independently represents a hydrocarbon group having 1 to 20 carbon atoms, and the hydrocarbon group may have a hetero-containing group. X each independently represents a hydroxyl group or a hydrolyzable group. a is 1, 2, or 3.)
[0014] Polymer (A) has a polymer skeleton composed of a plurality of repeating units and a terminal structure bonded to the end of the polymer skeleton. The polymer skeleton refers to the polymer main chain composed of a plurality of repeating units. The polymer skeleton of polymer (A) may be linear or branched. A linear polymer skeleton can be formed by using an initiator having two hydroxyl groups in one molecule in the polymerization method for forming the polymer skeleton, and a branched polymer skeleton can be formed by using an initiator having three or more hydroxyl groups in one molecule.
[0015] The polymer skeleton is preferably a polymer skeleton composed only of a plurality of repeating units connected to each other, or a polymer skeleton composed only of these, including the structure derived from the initiator used during polymerization in addition to the plurality of repeating units. The repeating unit refers to an oxyalkylene unit, for example, an oxyalkylene unit having 2 to 6 carbon atoms, preferably 2 to 4 carbon atoms.
[0016] The term "terminal structure" refers to a portion that does not contain repeating units constituting the polymer skeleton and is bonded to the end of the polymer skeleton. Preferably, the terminal structure is bonded to an oxyalkylene unit located at the end of the polymer skeleton via an oxygen atom. Furthermore, it is preferable that the hydrolyzable silyl group present in polymer (A) is included in the terminal structure. In this case, each terminal structure may contain a hydrolyzable silyl group, or terminal structures containing hydrolyzable silyl groups and terminal structures not containing hydrolyzable silyl groups may coexist.
[0017] It is preferable that polymer (A) has hydrolyzable silyl groups at two or more ends of its polymer skeleton. If the polymer skeleton of polymer (A) is linear, it can be said that polymer (A) has hydrolyzable silyl groups at both ends of its polymer skeleton. In this case, it is preferable that polymer (A) is a polymer component composed of polymer molecules having hydrolyzable silyl groups at two or more ends of its polymer skeleton, but polymer (A) as a whole may also contain polymer molecules having a hydrolyzable silyl group at only one end of its polymer skeleton, and / or polymer molecules that do not have a hydrolyzable silyl group.
[0018] The number of hydrolyzable silyl groups per molecule of polymer (A) is preferably more than 1 on average, more preferably 1.1 or more, and even more preferably 1.3 or more. The upper limit is preferably 5 or less, and more preferably 4 or less.
[0019] Furthermore, the average ratio of the number of hydrolyzable silyl groups to the number of terminals of the polymer backbone in one molecule of polymer (A) is not particularly limited and may be 1.0 or less, or greater than 1.0. When low modulus and high elongation are required, the average ratio is preferably 1.0 or less, and more preferably 0.8 or less. The lower limit of the average ratio is preferably 0.3 or more, and more preferably 0.5 or more. In order to exhibit high strength, the average ratio is preferably greater than 1.0, more preferably 1.1 or more, even more preferably 1.3 or more, and particularly preferably 1.5 or more. The upper limit of the average ratio is preferably 5 or less, and more preferably 3 or less. The numerical value of the average ratio can be determined by the method described in the examples. In addition, the numerical value of the average ratio can also be calculated from the results of GPC measurement and NMR measurement of polymer (A) by methods other than those described in the examples.
[0020] In this specification, the average ratio of the number of hydrolyzable silyl groups to the number of terminals of the polymer skeleton refers to the average number of hydrolyzable silyl groups contained per terminal structure of the polymer skeleton, and is expressed as average number of hydrolyzable silyl groups in one polymer molecule / number of terminals of the polymer skeleton in one polymer molecule. The number of terminals of the polymer skeleton in one polymer molecule is 2 if the polymer skeleton is entirely linear, and 3 or more if the polymer skeleton is entirely branched. Furthermore, if the polymer skeleton is a mixture of linear and branched structures, it may be between 2 and 3.
[0021] <Hydrolyzable silyl group> The hydrolyzable silyl group of polymer (A) is of general formula (1): -Si(R 1 ) 3-a (X) a (1) (In the formula, R 1 Each of these independently represents a hydrocarbon group having 1 to 20 carbon atoms, and the hydrocarbon group may have a hetero-containing group. Each of these independently represents a hydroxyl group or a hydrolyzable group. a is 1, 2, or 3. It is represented as follows.
[0022] R 1 R is a hydrocarbon group with 1 to 20 carbon atoms. 1 The number of carbon atoms in the hydrocarbon group is preferably 1 to 12, more preferably 1 to 6, and particularly preferably 1 to 4. The hydrocarbon group may be an unsubstituted hydrocarbon group or a hydrocarbon group having substituents.
[0023] R 1 A hetero-containing group that a hydrocarbon group may have as a substituent is a group containing a heteroatom. Here, atoms other than carbon atoms and hydrogen atoms are considered heteroatoms.
[0024] Suitable examples of heteroatoms include N, O, S, P, Si, and halogen atoms. For hetero-containing groups, the total number of carbon atoms and heteroatoms is preferably 1 to 10, more preferably 1 to 6, and even more preferably 1 to 4.
[0025] Preferred examples of hetero-containing groups include hydroxyl groups; mercapto groups; halogen atoms such as Cl, Br, I, and F; nitro groups; cyano groups; alkoxy groups such as methoxy groups, ethoxy groups, n-propyloxy groups, and isopropyloxy groups; alkylthio groups such as methylthio groups, ethylthio groups, n-propylthio groups, and isopropylthio groups; acyl groups such as acetyl groups, propionyl groups, and butanoyl groups; acyloxy groups such as acetyloxy groups, propionyloxy groups, and butanoyloxy groups; substituted or unsubstituted amino groups such as amino groups, methylamino groups, ethylamino groups, dimethylamino groups, and diethylamino groups; substituted or unsubstituted aminocarbonyl groups such as aminocarbonyl groups, methylaminocarbonyl groups, ethylaminocarbonyl groups, dimethylaminocarbonyl groups, and diethylaminocarbonyl groups; and cyano groups.
[0026] R 1 If R is a hydrocarbon group having a hetero-containing group, 1The total number of carbon atoms and heteroatoms in is preferably 2 to 30, more preferably 2 to 18, even more preferably 2 to 10, and particularly preferably 2 to 6.
[0027] R 1 Specific examples of hydrocarbon groups with 1 to 20 carbon atoms include alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, 2-ethyl-n-hexyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-octadecyl, n-nonadecyl, and n-icosyl; vinyl Examples include alkenyl groups such as 2-propenyl, 3-butenyl, and 4-pentenyl groups; cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl groups; aryl groups such as phenyl, naphthalene-1-yl, naphthalene-2-yl, o-phenylphenyl, m-phenylphenyl, and p-phenylphenyl groups; and aralkyl groups such as benzyl, phenethyl, naphthalene-1-ylmethyl, and naphthalene-2-ylmethyl groups. These hydrocarbon groups, including those substituted with the aforementioned hetero-containing groups, are also R 1 This is preferable.
[0028] R 1 Suitable examples include, for example, alkyl groups such as methyl and ethyl groups; alkyl groups having hetero-containing groups such as chloromethyl and methoxymethyl groups; cycloalkyl groups such as cyclohexyl groups; aryl groups such as phenyl groups; aralkyl groups such as benzyl groups; and so on. 1 The preferred group is a methyl group, a methoxymethyl group, or a chloromethyl group; more preferably a methyl group or a methoxymethyl group; and even more preferably a methyl group.
[0029] Examples of X include hydroxyl groups, hydrogen, halogens, alkoxy groups, acyloxy groups, ketoximate groups, amino groups, amide groups, acid amide groups, aminooxy groups, mercapto groups, and alkenyloxy groups. Among these, alkoxy groups such as methoxy and ethoxy groups are more preferred due to their mild hydrolysis and ease of handling, with methoxy and ethoxy groups being particularly preferred.
[0030] a is 1, 2, or 3. It is preferable that a be 2 or 3, and more preferably 3.
[0031] Specific examples of the hydrolyzable silyl group include, but are not limited to, trimethoxysilyl, triethoxysilyl, tris(2-propenyloxy)silyl, triacetoxysilyl, dimethoxymethylsilyl, diethoxymethylsilyl, dimethoxyethylsilyl, (chloromethyl)dimethoxysilyl, (chloromethyl)diethoxysilyl, (methoxymethyl)dimethoxysilyl, (methoxymethyl)diethoxysilyl, (N,N-diethylaminomethyl)dimethoxysilyl, and (N,N-diethylaminomethyl)diethoxysilyl. Among these, dimethoxymethylsilyl, trimethoxysilyl, triethoxysilyl, and (methoxymethyl)dimethoxysilyl are preferred because they yield cured products with good mechanical properties. From the viewpoint of activity, trimethoxysilyl group, (chloromethyl)dimethoxysilyl group, and (methoxymethyl)dimethoxysilyl group are more preferred, and trimethoxysilyl group and (methoxymethyl)dimethoxysilyl group are particularly preferred. From the viewpoint of stability, dimethoxymethylsilyl group and triethoxysilyl group are more preferred, and dimethoxymethylsilyl group is particularly preferred.
[0032] In polymer (A), the terminal structure having a hydrolyzable silyl group is not particularly limited, but typical examples include terminal structures represented by any of the following general formulas (2) to (6).
[0033] -OR2 -CH(R 3 )-CH2-Si(R 1 ) 3-a (X) a (2) In formula (2), R 2 R represents a direct bond or a divalent hydrocarbon group with 1 to 4 carbon atoms. 3 R represents hydrogen or an alkyl group having 1 to 6 carbon atoms. The oxygen at the far left indicates oxygen in a repeating unit located at the end of a polymer skeleton composed of multiple linked repeating units, or oxygen bonded to a repeating unit located at the end of the polymer skeleton. 1 X and a are the same as those described above for equation (1).
[0034] R 2 Preferably, the hydrocarbon group is a divalent hydrocarbon group having 1 to 3 carbon atoms, and more preferably a divalent hydrocarbon group having 1 to 2 carbon atoms. The hydrocarbon group is preferably an alkylene group, and methylene, ethylene, propylene, or butylene groups can be used. Methylene is particularly preferred.
[0035] R 3 Preferably, the alkyl group is hydrogen or an alkyl group having 1 to 4 carbon atoms, and more preferably, hydrogen or an alkyl group having 1 to 3 carbon atoms. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, and the like. 3 Hydrogen, methyl groups, and ethyl groups are preferred, with hydrogen and methyl groups being more preferred.
[0036] [ka]
[0037] In formula (3), R 4 R is a direct bond or a divalent bond group with 1 to 6 carbon atoms. 5R is hydrogen or a hydrocarbon group having 1 to 10 carbon atoms. n is an integer from 1 to 10. The oxygen at the leftmost end indicates oxygen in a repeating unit located at the end of a polymer skeleton composed of multiple linked repeating units, or oxygen bonded to a repeating unit located at the end of the polymer skeleton. 1 , R 2 , R 3 X and a are the same as those described above for equations (1) and (2).
[0038] R 4 This may be a divalent organic group having 1 to 6 carbon atoms. The organic group is preferably a hydrocarbon group or a hydrocarbon group containing an oxygen atom. The number of carbon atoms is preferably 1 to 4, more preferably 1 to 3, and even more preferably 1 to 2. Preferably, it is -CH2OCH2-, -CH2O-, -CH2-, and more preferably -CH2OCH2-.
[0039] R 5 Preferably, the group is hydrogen or a hydrocarbon group having 1 to 5 carbon atoms; more preferably, hydrogen or a hydrocarbon group having 1 to 3 carbon atoms; and even more preferably, hydrogen or a hydrocarbon group having 1 to 2 carbon atoms. Particularly preferred are a hydrogen atom and a methyl group, and most preferably, a hydrogen atom.
[0040] The terminal structure represented by general formula (3) represents a single terminal structure bonded to one end of the polymer backbone. Although formula (3) shows two or more reactive silicon groups, formula (3) does not indicate two or more terminals, but rather indicates that two or more reactive silicon groups exist within a single terminal structure. Furthermore, formula (3) does not contain a polymer backbone composed of repeating units which are oxyalkylene units, except for the oxygen at the left end. In other words, the n structures in parentheses in formula (3) do not correspond to repeating units in the polymer backbone.
[0041] [ka]
[0042] [ka]
[0043] [ka]
[0044] In formulas (4) to (6), R 6 , and R 7 Each of these independently represents hydrogen, an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, or a silyl group. The oxygen at the far left indicates oxygen in a repeating unit located at the end of a polymer skeleton composed of multiple linked repeating units, or oxygen bonded to a repeating unit located at the end of the polymer skeleton. 1 X and a are the same as those described above for equation (1).
[0045] R 6 , and R 7 Each of these is independently one of hydrogen, an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, and a silyl group. The number of carbon atoms in the alkyl group is preferably 1 to 12, more preferably 1 to 6, and particularly preferably 1 to 4. The number of carbon atoms in the aryl group is preferably 6 to 12, more preferably 6 to 10. The number of carbon atoms in the aralkyl group is preferably 7 to 12.
[0046] R 6 , and R 7 Specifically, these include hydrogen; alkyl groups such as methyl, ethyl, and cyclohexyl groups; aryl groups such as phenyl and tolyl groups; aralkyl groups such as benzyl and phenethyl groups; and silyl groups such as trimethylsilyl groups. Among these, hydrogen, methyl, and trimethylsilyl groups are preferred, hydrogen and methyl groups are more preferred, and hydrogen is even more preferred.
[0047] <Main chain structure> The main chain structure of polymer (A) may be linear or branched.
[0048] Examples of the main chain skeleton of polymer (A) include polyoxyethylene, polyoxypropylene, polyoxybutylene, polyoxytetramethylene, polyoxyethylene-polyoxypropylene copolymer, and polyoxypropylene-polyoxybutylene copolymer. The above polymers may be mixed in block form, graft form, etc. Among these, polyoxypropylene is particularly preferred.
[0049] Polymer (A) may be a polymer having any one of the main chain skeletons described above, or a mixture of polymers having different main chain skeletons. Furthermore, the mixture may be a mixture of polymers manufactured separately, or a mixture manufactured simultaneously to achieve any desired mixed composition.
[0050] The number-average molecular weight of polymer (A) is not particularly limited, but is preferably 3,000 to 100,000, more preferably 3,000 to 50,000, and particularly preferably 3,000 to 30,000 as the polystyrene-equivalent molecular weight in GPC. When the number-average molecular weight is within the above range, the amount of hydrolyzable silyl groups introduced is appropriate, making it easy to obtain polymer (A) with a manageable viscosity and excellent workability while keeping manufacturing costs within a reasonable range.
[0051] The molecular weight of polymer (A) can also be expressed as the end-group-reduced molecular weight, which is determined by directly measuring the end-group concentration of the polymer precursor before the introduction of hydrolyzable silyl groups using titration analysis based on the principles of the hydroxyl value measurement method specified in JIS K 1557 and the iodine value measurement method specified in JIS K 0070, and considering the structure of the polymer (degree of branching determined by the polymerization initiator used). Alternatively, the end-group-reduced molecular weight of polymer (A) can be determined by creating a calibration curve between the number-average molecular weight obtained by general GPC measurement of the polymer precursor and the above-mentioned end-group-reduced molecular weight, and then converting the number-average molecular weight obtained by GPC of polymer (A) to the end-group-reduced molecular weight.
[0052] The molecular weight distribution (Mw / Mn) of polymer (A) is not particularly limited, but a narrow range is preferred. Specifically, it is preferably 1.6 or less, more preferably 1.4 or less, even more preferably 1.3 or less, and particularly preferably 1.2 or less. The molecular weight distribution of polymer (A) can be determined from the number-average molecular weight and weight-average molecular weight obtained by GPC measurement.
[0053] <(A) Method for producing polyoxyalkylene polymers having hydrolyzable silyl groups as shown in general formula (1)> Next, a method for producing polymer (A) will be described. Polymer (A) can be produced by introducing hydrolyzable silyl groups into a precursor polymer that is capable of having hydrolyzable silyl groups introduced into it. Specifically, polymer (A) can be produced by first introducing olefin groups into a polyoxyalkylene polymer (E) having hydroxyl groups at its terminals by utilizing the reactivity of the hydroxyl groups to obtain a precursor polymer having olefin groups, and then reacting the precursor polymer with a hydrolyzable silyl group-containing compound that is reactive with the olefin groups to introduce hydrolyzable silyl groups.
[0054] (polymerization) The polymer skeleton of polyoxyalkylene polymers can be formed by polymerizing an epoxy compound onto a hydroxyl group-containing initiator using conventionally known methods, thereby obtaining a polyoxyalkylene polymer (E) having hydroxyl groups at its ends. While there are no particular limitations on the specific polymerization method, a polymerization method using a complex metal cyanide catalyst such as a zinc hexacyanocobaltate glyme complex is preferred because it yields hydroxyl-terminated polymers with a small molecular weight distribution (Mw / Mn).
[0055] The initiator having a hydroxyl group is not particularly limited, but examples include ethylene glycol, propylene glycol, glycerin, pentaerythritol, low molecular weight polyoxypropylene glycol, low molecular weight polyoxypropylene triol, butanol, allyl alcohol, low molecular weight polyoxypropylene monoallyl ether, and low molecular weight polyoxypropylene monoalkyl ether.
[0056] The epoxy compound is not particularly limited, but examples include alkylene oxides such as ethylene oxide and propylene oxide, and glycidyl ethers such as methyl glycidyl ether and butyl glycidyl ether. Propylene oxide is preferred.
[0057] (Reaction with alkali metal salts) In introducing olefin groups to a polyoxyalkylene polymer (E) having hydroxyl groups at its termini, it is preferable to first react the polyoxyalkylene polymer (E) with an alkali metal salt to convert the terminal hydroxyl groups into metal-oxy groups. Alternatively, a complex metal cyanide catalyst can be used instead of an alkali metal salt. Through these steps, a metal-oxy group-terminated polyoxyalkylene polymer (F) is formed.
[0058] The alkali metal salt is not particularly limited, but examples include sodium hydroxide, sodium alkoxide, potassium hydroxide, potassium alkoxide, lithium hydroxide, lithium alkoxide, cesium hydroxide, cesium alkoxide, and the like. Due to ease of handling and solubility, sodium hydroxide, sodium methoxide, sodium ethoxide, sodium tert-butoxide, potassium hydroxide, potassium methoxide, potassium ethoxide, and potassium tert-butoxide are preferred, with sodium methoxide and sodium tert-butoxide being more preferred. Sodium methoxide is preferred in terms of availability. The alkali metal salt may be used in the reaction in a dissolved state in the solvent.
[0059] (Reaction with electrophile (G)) By reacting the metal-oxy group-terminated polyoxyalkylene polymer (F) obtained as described above with an electrophile (G) having an olefin group, the metal-oxy groups can be converted into a structure containing an olefin group. This results in the formation of a polyoxyalkylene polymer (H) having an olefin group in its terminal structure.
[0060] The electrophile (G) having an olefin group is not particularly limited as long as it is a compound that can react with the metaloxy group of the polyoxyalkylene polymer (F) and introduce an olefin group into the polyoxyalkylene polymer. Examples include organic halides (G1) having an olefin group and epoxy compounds (G2) having an olefin group.
[0061] An organic halide (G1) having an olefin group, which is one embodiment of the electrophile (G), can react with the metaloxy group by a halogen substitution reaction to form an ether bond, thereby introducing a structure containing an olefin group as a terminal structure of a polyoxyalkylene polymer.
[0062] Specific examples of organic halides (G1) having an olefin group are not particularly limited, but include vinyl chloride, allyl chloride, methallyl chloride, vinyl bromide, allyl bromide, methallyl bromide, vinyl iodide, allyl iodide, and methallyl iodide. Allyl chloride and methallyl chloride are preferred due to their ease of handling. Furthermore, methallyl chloride, methallyl bromide, and methallyl iodide are preferred because they improve the average ratio of the number of hydrolyzable silyl groups to the number of terminals in the polymer skeleton.
[0063] Furthermore, as the organic halide (G1) having an olefin group, a halogenated hydrocarbon compound having a carbon-carbon triple bond can also be used. The polyoxyalkylene polymer (J) obtained by reacting this compound has a carbon-carbon triple bond at the end of the polymer backbone. When a hydrolyzable silyl group is introduced into such a polymer (J), the atoms adjacent to the hydrolyzable silyl group will have a carbon-carbon double bond, and a terminal structure represented by any of the general formulas (4) to (6) above can be formed.
[0064] Examples of halogenated hydrocarbon compounds having a carbon-carbon triple bond include propargyl chloride, 1-chloro-2-butyne, 4-chloro-1-butyne, 1-chloro-2-octyne, 1-chloro-2-pentine, 1,4-dichloro-2-butyne, 5-chloro-1-pentine, 6-chloro-1-hexine, propargyl bromide, 1-bromo-2-butyne, 4-bromo-1-butyne, and 1-bromo-2 Examples include octyne, 1-bromo-2-pentine, 1,4-dibromo-2-butine, 5-bromo-1-pentine, 6-bromo-1-hexine, propargyl iodide, 1-iodo-2-butine, 4-iodo-1-butine, 1-iodo-2-octyne, 1-iodo-2-pentine, 1,4-diiodo-2-butine, 5-iodo-1-pentine, and 6-iodo-1-hexine. Among these, propargyl chloride, propargyl bromide, and propargyl iodide are more preferred. In addition, halogenated hydrocarbon compounds having a carbon-carbon double bond may be used simultaneously with halogenated hydrocarbon compounds having a carbon-carbon triple bond.
[0065] Another embodiment of the electrophile (G), an epoxy compound (G2) having an olefin group, can react with the metaloxy group by a ring-opening addition reaction of the epoxy group to form an ether bond, thereby introducing a structure containing an olefin group and a hydroxyl group as the terminal structure of a polyoxyalkylene polymer. In the ring-opening addition reaction, by adjusting the amount of epoxy compound (G2) used relative to the metaloxy group and the reaction conditions, one or more epoxy compounds (G2) can be added to a single metaloxy group.
[0066] The epoxy compound (G2) having the olefin group is not limited to the following, but is a general formula (7):
[0067] [ka]
[0068] It can be expressed as follows: In equation (7), R 8 and R 9These are the R values mentioned above for general formula (3), respectively. 4 and R 5 It is the same base as [the other].
[0069] Specific examples of epoxy compounds (G2) having an olefin group are not particularly limited, but allyl glycidyl ether, methallyl glycidyl ether, glycidyl acrylate, glycidyl methacrylate, and butadiene monooxide are preferred from the viewpoint of reaction activity, and allyl glycidyl ether is particularly preferred.
[0070] As described above, when an epoxy compound (G2) having an olefin group is reacted with a metaloxy group-terminated polyoxyalkylene polymer (F), a new metaloxy group is generated by ring-opening of the epoxy group. Therefore, after reacting with the epoxy compound (G2), the aforementioned organic halide (G1) having an olefin group can be reacted consecutively. The same compound as described above can be used as the organic halide (G1) having an olefin group used in this embodiment, and the amount used and reaction temperature are also the same as above. This method is preferable because it can increase the amount of olefin group and hydrolyzable silyl group introduced into the polymer. When a polyoxyalkylene polymer (H) having an olefin group in its terminal structure, obtained by the method using epoxy compound (G2) and organic halide (G1) is subjected to the introduction of hydrolyzable silyl groups described below, a terminal structure represented by the general formula (3) can be formed.
[0071] (Introduction of hydrolyzable silyl groups) By subjecting the polyoxyalkylene polymer (H) having an olefin group in its terminal structure or the polyoxyalkylene polymer (J) (precursor polymer) having a carbon-carbon triple bond in its terminal structure (obtained above) to a hydrosilylation reaction with a hydrosilane compound (K) having a hydrolyzable silyl group, a hydrolyzable silyl group can be introduced into the polymer. This produces a polyoxyalkylene polymer (A) containing a hydrolyzable silyl group. The hydrosilylation reaction has the advantages of being easy to carry out, allowing for easy adjustment of the amount of hydrolyzable silyl group introduced, and resulting in a polymer with stable physical properties.
[0072] Specific examples of the hydrosilane compound (K) having the hydrolyzable silyl group include halosilanes such as trichlorosilane, dichloromethylsilane, chlorodimethylsilane, dichlorophenylsilane, (chloromethyl)dichlorosilane, (dichloromethyl)dichlorosilane, bis(chloromethyl)chlorosilane, (methoxymethyl)dichlorosilane, (dimethoxymethyl)dichlorosilane, and bis(methoxymethyl)chlorosilane; trimethoxysilane, triethoxysilane, dimethoxymethylsilane, diethoxy Methylsilane, dimethoxyphenylsilane, ethyldimethoxysilane, methoxydimethylsilane, ethoxydimethylsilane, (chloromethyl)methylmethoxysilane, (chloromethyl)dimethoxysilane, (chloromethyl)diethoxysilane, bis(chloromethyl)methoxysilane, (methoxymethyl)methylmethoxysilane, (methoxymethyl)dimethoxysilane, bis(methoxymethyl)methoxysilane, (methoxymethyl)diethoxysilane, (ethoxymethyl)diethoxysilane, (3,3,3-tri Fluoropropyl)dimethoxysilane, (N,N-diethylaminomethyl)dimethoxysilane, (N,N-diethylaminomethyl)diethoxysilane, [(chloromethyl)dimethoxysilyloxy]dimethylsilane, [(chloromethyl)diethoxysilyloxy]dimethylsilane, [(methoxymethyl)dimethoxysilyloxy]dimethylsilane, [(methoxymethyl)diethoxysilyloxy]dimethylsilane, [(diethylaminomethyl)dimethoxysilyloxy]dimethylsilane, [(3,3,3-tri Examples include alkoxysilanes such as [fluoropropyl]dimethoxysilyloxy]dimethylsilane; acyloxysilanes such as diacetoxymethylsilane and diacetoxyphenylsilane; ketoximate silanes such as bis(dimethylketoximate)methylsilane and bis(cyclohexylketoximate)methylsilane; isopropenyloxysilanes (deacetone-free type) such as triisopropenyloxysilane, (chloromethyl)diisopropenyloxysilane, and (methoxymethyl)diisopropenyloxysilane.
[0073] Hydrosilylation reactions are preferably carried out in the presence of a hydrosilylation catalyst to accelerate the reaction. Known hydrosilylation catalysts include metals such as cobalt, nickel, iridium, platinum, palladium, rhodium, and ruthenium, as well as complexes thereof, and these can be used. Specifically, examples include platinum supported on a carrier such as alumina, silica, or carbon black; chloroplatinic acid; chloroplatinic acid complexes consisting of chloroplatinic acid with alcohols, aldehydes, or ketones; platinum-olefin complexes [e.g., Pt(CH2=CH2)2(PPh3), Pt(CH2=CH2)2Cl2]; platinum-vinylsiloxane complexes [e.g., Pt{(vinyl)Me2SiOSiMe2(vinyl)}, Pt{Me(vinyl)SiO}4]; platinum-phosphine complexes [e.g., Ph(PPh3)4, Pt(PBu3)4]; and platinum-phosphine complexes [e.g., Pt{P(OPh)3}4]. From the viewpoint of reaction efficiency, platinum catalysts such as chloroplatinic acid and platinum-vinylsiloxane complexes are preferred.
[0074] Another method for producing polymer (A) involves reacting a polyoxyalkylene polymer (E) (precursor polymer) having hydroxyl groups at its termini with a compound (L) containing hydrolyzable silyl and isocyanate groups in one molecule to form urethane bonds and introduce hydrolyzable silyl groups. Polymer (A) can also be produced by this method.
[0075] The compound (L) having a hydrolyzable silyl group and an isocyanate group in one molecule is not particularly limited as long as it has both an isocyanate group capable of urethane reaction with the hydroxyl group of the polyoxyalkylene polymer (E) and a hydrolyzable silyl group in one molecule. Specific examples include (3-isocyanate propyl)trimethoxysilane, (3-isocyanate propyl)dimethoxymethylsilane, (3-isocyanate propyl)triethoxysilane, (3-isocyanate propyl)diethoxymethylsilane, (isocyanate methyl)trimethoxysilane, (isocyanate methyl)triethoxysilane, (isocyanate methyl)dimethoxymethylsilane, and (isocyanate methyl)diethoxymethylsilane.
[0076] The urethane reaction may be carried out without a urethane catalyst, but it may also be carried out in the presence of a urethane catalyst to improve the reaction rate or reaction efficiency. Such urethane catalysts include, for example, those listed in *Polyurethanes: Chemistry and Technology, Part I, Table 30, Chapter 4, Saunders and Frisch, Interscience Publishers, New York, 1963*, and other conventionally known urethane catalysts. Specifically, examples include, but are not limited to, organotin compounds, bismuth compounds, and base catalysts such as organic amines.
[0077] As yet another method for producing polymer (A), an excess of a polyisocyanate compound (M) is reacted with a polyoxyalkylene polymer (E) having hydroxyl groups at its terminals to produce a polymer (precursor polymer) having isocyanate groups at its terminals, and then a compound (N) having a group that reacts with isocyanate groups (e.g., an amino group) and a hydrolyzable silyl group can be reacted with this precursor polymer. This method also produces a polyoxyalkylene polymer (A) having hydrolyzable silyl groups at the terminals of the polymer backbone.
[0078] Examples of polyisocyanate compounds (M) include aromatic polyisocyanates such as toluene(trylene) diisocyanate, diphenylmethane diisocyanate, and xylylene diisocyanate; and aliphatic polyisocyanates such as isophorone diisocyanate and hexamethylene diisocyanate.
[0079] Examples of compounds (N) having a group that reacts with an isocyanate group and a hydrolyzable silyl group include γ-aminopropyltrimethoxysilane, γ-aminopropyldimethoxymethylsilane, γ-aminopropyltriethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropyldimethoxymethylsilane, N-(β-aminoethyl)-γ-aminopropyltriethoxysilane, γ-(N-phenyl)aminopropyltrimethoxysilane, γ-(N-phenyl)aminopropyldi Examples include amino group-containing silanes such as methoxymethylsilane, N-ethylaminoisobutyltrimethoxysilane, N-ethylaminoisobutyldimethoxymethylsilane, N-cyclohexylaminomethyltrimethoxysilane, and N-cyclohexylaminomethyldimethoxymethylsilane; hydroxyl group-containing silanes such as γ-hydroxypropyltrimethoxysilane and γ-hydroxypropyldimethoxymethylsilane; and mercapto group-containing silanes such as γ-mercaptopropyltrimethoxysilane and γ-mercaptopropyldimethoxymethylsilane.
[0080] As yet another method for producing polymer (A), a polyoxyalkylene polymer (H) (precursor polymer) having an olefin group in its terminal structure can be treated with a compound (P) having a hydrolyzable silyl group and a mercaptan group in one molecule. This method introduces the hydrolyzable silyl group by forming a sulfide bond through the addition of the mercaptan group to the olefin group. This method also allows for the production of a polyoxyalkylene polymer (A) having a hydrolyzable silyl group at the terminal end of the polymer backbone.
[0081] The compound (P) having a hydrolyzable silyl group and a mercaptan group in one molecule is not particularly limited as long as it has both a mercaptan group capable of addition to the olefin group of the polyoxyalkylene polymer (H) and a hydrolyzable silyl group in one molecule. Specific examples include (3-mercaptopropyl)methyldimethoxysilane, (3-mercaptopropyl)trimethoxysilane, (3-mercaptopropyl)methyldiethoxysilane, (3-mercaptopropyl)triethoxysilane, (mercaptomethyl)methyldimethoxysilane, (mercaptomethyl)trimethoxysilane, (mercaptomethyl)methyldiethoxysilane, and (mercaptomethyl)triethoxysilane.
[0082] The addition reaction of a mercaptan group to an olefin group may be carried out without the use of a radical initiator, but it may also be carried out in the presence of a radical initiator to improve the reaction rate or reaction rate. Conventional radical initiators can be used. Specifically, azo initiators and peroxide initiators are examples, but are not limited to these.
[0083] Among known radical initiators, catalysts with low activity towards hydrolyzable silyl groups are preferred, and from this viewpoint, azo-based initiators such as 2,2'-azobis(isobutyronitrile) (AIBN), 2,2'-azobis(2-methylbutyronitrile) (V-59), and 2,2'-azobis(1-methylcyclohexanecarbonitride) (V-40) are particularly preferred.
[0084] <<(B) Metal compounds comprising at least one metal element selected from the group consisting of aluminum and zinc, and a chelate compound acting as a ligand>> The heat-curable composition according to this embodiment contains a metal compound (hereinafter also referred to as metal compound (B)) as a curing catalyst for polymer (A), which includes at least one metal element selected from the group consisting of (B) aluminum and zinc, and a chelate compound that acts as a ligand.
[0085] The metallic element contained in the metallic compound (B) is at least one selected from the group consisting of aluminum and zinc, but aluminum is more preferable because it has good stability against air.
[0086] Metal compound (B) contains a chelate compound as a ligand for the metal element. As chelating compounds, commonly known compounds can be used, and specific examples include nitrogen-containing compounds such as 1,2-diaminoethane, N,N'-di-tert-butylethylenediamine, 1,2-cyclohexanediamine, 2,2'-bipyridine, 2,2'-(methylimino)bis(N,N-di-n-octylacetamide), tris(2-aminoethyl)amine, and 3,3'-iminobis(N,N-dimethylpropylamine); and β-di-acetylacetone, trifluoroacetylacetone, 3-phenylacetylacetone, 1-phenyl-1,3-butanedione, 2,4-hexanedione, 2,4-heptanedione, dibenzoylmethane, and 1,3-cyclohexanedione. Examples include oxygen-containing compounds such as ketones, β-ketoesters such as methyl acetoacetate, ethyl acetoacetate, propyl acetoacetate, butyl acetoacetate, methyl pivaloyl acetate, methyl isobutyroyl acetate, methyl caproyl acetate, and methyl lauroyl acetate; oxygen- and nitrogen-containing compounds such as β-ketoamides such as N-methyl-3-oxo-N-phenylbutanamide; and phosphorus-containing compounds such as 1,2-bis(diphenylphosphino)ethane, 1,2-bis(diphenylphosphino)propane, 1,2-bis(diphenylphosphino)butane, 1,1'-bis(diphenylphosphino)ferrocene, 2,2'-bis(diphenylphosphino)-1,1'-binaphthyl, and xanthophos.
[0087] Among these, β-dicarbonyl compounds such as β-diketones, β-ketoesters, and β-ketoamides are preferred, β-diketones or β-ketoesters are more preferred, β-diketones are even more preferred, and acetylacetone is most preferred.
[0088] Specific examples of the metal compound (B) include aluminum trisacetylacetonate, aluminum trisethylacetoacetate, and zinc bisacetylacetonate. Among these, aluminum trisacetylacetonate and zinc bisacetylacetonate are preferred, with aluminum trisacetylacetonate being even more preferred due to its good stability in air and low solubility in the heat-curable composition according to this embodiment.
[0089] The content of metal compound (B) is preferably 0.1 to 10 parts by weight, and more preferably 0.2 to 5 parts by weight, per 100 parts by weight of polymer (A).
[0090] <<(C) Chelate compound>> The heat-curable composition according to this embodiment further contains (C) a chelate compound (hereinafter also referred to as chelate compound (C)) in addition to the polymer (A) and the metal compound (B).
[0091] By adding a chelating compound (C), the activity of the metal compound (B), which acts as a curing catalyst, can be reduced, thereby maintaining long-term storage stability. In addition, during heat curing, the vaporization of the chelating compound enhances the activity of the metal compound (B), accelerating the curing process.
[0092] As the chelate compound (C), the chelate compound described in the above metal compound (B) can be used, but it is preferably a β-dicarbonyl compound, more preferably a β-diketone or β-ketoester, even more preferably a β-diketone, and most preferably acetylacetone due to its availability and suitable boiling point.
[0093] Furthermore, it is preferable that the chelate compound (C) is the same compound as the chelate compound contained in the metal compound (B).
[0094] The content of the chelate compound (C) is preferably 0.1 to 10 parts by weight, more preferably 0.2 to 5 parts by weight, and even more preferably 0.3 to 3 parts by weight, per 100 parts by weight of polymer (A).
[0095] Furthermore, the ratio of the total number of moles of the chelate compound and chelate compound (C) in metal compound (B) to the number of moles of the metal element in metal compound (B) is preferably greater than 3, more preferably 4 or greater, and even more preferably 5 or greater. Having the ratio within the above range makes it easier to maintain the long-term storage stability of the curable composition.
[0096] <<(D) Epoxy compounds containing at least two epoxy groups in one molecule>> The heat-curable composition according to this embodiment may further contain, in addition to the polymer (A), metal compound (B), and chelate compound (C), an epoxy compound (D) containing at least two epoxy groups per molecule (hereinafter also referred to as epoxy compound (D)). By adding the epoxy compound (D) containing at least two epoxy groups per molecule, an effect of improved adhesion can be obtained. Furthermore, an effect of improved curability can be obtained after the curable composition is stored under sealed conditions.
[0097] Specific examples of epoxy compounds (D) include 3',4'-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate (manufactured by Daicel Corporation, trade name: Celoxide 2021P), ε-caprolactone-modified 3',4'-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate (manufactured by Daicel Corporation, trade name: Celoxide 2081), and (3,3',4,4'-diepoxy)bicyclohexyl.
[0098] The epoxy compound (D) does not include epoxy group-containing silanes that correspond to the silane coupling agents described later.
[0099] As the epoxy compound (D), epoxy resins containing at least two epoxy groups in one molecule can also be used. Specific examples of such epoxy resins include flame-retardant epoxy resins such as epichlorohydrin-bisphenol A type epoxy resin, epichlorohydrin-bisphenol F type epoxy resin, glycidyl ether of tetrabromobisphenol A, novolac type epoxy resin, hydrogenated bisphenol A type epoxy resin, glycidyl ether type epoxy resin of bisphenol A propylene oxide adduct, p-oxybenzoic acid glycidyl ether ester type epoxy resin, m-aminophenol epoxy resin, diaminodiphenylmethane epoxy resin, urethane-modified epoxy resin, various alicyclic epoxy resins, glycidyl ethers of polyhydric alcohols such as N,N-diglycidylaniline, N,N-diglycidyl-o-toluidine, triglycidyl isocyanurate, polyalkylene glycol diglycidyl ether, and glycerin, hydantoin type epoxy resin, and epoxidized unsaturated polymers such as petroleum resins.
[0100] Among these, alicyclic epoxy compounds are preferred, with 3',4'-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate (manufactured by Daicel Corporation, trade name: Celoxide 2021P), ε-caprolactone-modified 3',4'-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate (manufactured by Daicel Corporation, trade name: Celoxide 2081), and (3,3',4,4'-diepoxy)bicyclohexyl being more preferred, and 3',4'-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate being particularly preferred.
[0101] The number of epoxy groups in epoxy compound (D) is preferably two or more per molecule, and more preferably two.
[0102] The content of epoxy compound (D) is preferably 0.1 to 20 parts by weight, more preferably 0.2 to 10 parts by weight, and even more preferably 0.3 to 5 parts by weight, per 100 parts by weight of polymer (A).
[0103] <(T) Zeolite-based adsorbent> In order to suppress the thickening of the curable composition during storage, the heat-curable composition according to this embodiment preferably further contains (T) a zeolite-based adsorbent (hereinafter also referred to as zeolite-based adsorbent (T)) as a dehydrating agent.
[0104] In the heat-curable composition according to this embodiment, the use of a zeolite-based adsorbent (T) provides appropriate water absorption during storage and promotes moisture curing by releasing moisture when heated. This is particularly effective when the moisture content of the curable composition is high, and it is preferable to add the zeolite-based adsorbent (T) when the moisture content after preparation of the curable composition is 400 ppm or more, and more preferable to add it when it is 500 ppm or more. The upper limit of the moisture content is preferably 2000 ppm or less, more preferably 1500 ppm or less, even more preferably 1200 ppm or less, and most preferably 1000 ppm or less.
[0105] Specific examples of zeolite-based adsorbents (T) include molecular sieves such as Molecular Sieve 3A, Molecular Sieve 4A, Molecular Sieve 5A, Molecular Sieve 3A-B, and Molecular Sieve 13X.
[0106] The content of the zeolite-based adsorbent (T) is not particularly limited, but is preferably 0.1 to 30 parts by weight, more preferably 0.5 to 20 parts by weight, and even more preferably 1 to 15 parts by weight, per 100 parts by weight of polymer (A).
[0107] <<Curable composition>> In addition to the polymer (A), metal compound (B), chelate compound (C), and epoxy compound (D), the heat-curable composition according to this embodiment may further contain various additives as needed.
[0108] Examples of such additives include silanol condensation catalysts other than metal compounds (B), fillers, adhesion promoters, plasticizers, anti-sagging agents, antioxidants, light stabilizers, UV absorbers, property modifiers, photocurable substances, oxygen-curable substances, and resins other than polymers (A).
[0109] Furthermore, for the purpose of adjusting the various physical properties of the curable composition or cured product, the heat-curable type curable composition according to this embodiment may further contain other additives as needed. Examples of such other additives include, for example, tackifying resins, solvents, diluents, surface modifiers, foaming agents, curing modifiers, flame retardants, silicates, radical inhibitors, metal deactivators, ozone degradation inhibitors, phosphorus-based peroxide decomposers, lubricants, pigments, and antifungal agents.
[0110] The following describes some of the most common additives. <Silanol condensation catalyst> The curable composition may also use a silanol condensation catalyst other than metal compound (B), as long as it does not interfere with the effect of metal compound (B).
[0111] Examples of silanol condensation catalysts other than metal compounds (B) include organotin compounds, metal carboxylate salts, amine compounds, carboxylic acids, and alkoxy metals.
[0112] Specific examples of organotin compounds include dibutyltin dilaurate, dibutyltin dioctanoate, dibutyltin bis(butylmaleate), dibutyltin diacetate, dibutyltin oxide, dibutyltin bis(acetylacetonate), dioctyltin bis(acetylacetonate), reaction products of dibutyltin oxide and silicate compounds, reaction products of dioctyltin oxide and silicate compounds such as dioctyltin bis(triethoxysilicate), and reaction products of dibutyltin oxide and phthalate esters.
[0113] Specific examples of metal carboxylate salts include tin carboxylate, bismuth carboxylate, titanium carboxylate, zirconium carboxylate, and iron carboxylate. Furthermore, salts combining the following carboxylic acids with various metals can be used as metal carboxylate salts.
[0114] Specific examples of amine compounds include octylamine, 2-ethylhexylamine, laurylamine, stearylamine, pyridine, amino group-containing silane coupling agents, and ketimine compounds.
[0115] Specific examples of carboxylic acids include acetic acid, propionic acid, butyric acid, 2-ethylhexanoic acid, lauric acid, stearic acid, oleic acid, linoleic acid, neodecanoic acid, and versatic acid.
[0116] Specific examples of alkoxy metals include titanium compounds such as tetrabutyl titanate, titanium tetrakis (acetylacetonate), and diisopropoxytitanium bis (ethylacetocetate), as well as zirconium compounds such as zirconium tetrakis (acetylacetonate).
[0117] Other silanol condensation catalysts that can be used include fluorine anion-containing compounds, photoacid generators, and photobase generators.
[0118] Silanol condensation catalysts other than metal compound (B) do not need to be used, but if they are used, the amount used is preferably 0.001 to 10 parts by weight, and more preferably 0.01 to 5 parts by weight, per 100 parts by weight of polymer (A).
[0119] <Filler> Various fillers can be incorporated into the curable composition. Examples of fillers include heavy calcium carbonate, colloidal calcium carbonate, magnesium carbonate, diatomaceous earth, clay, talc, kaolin, silicine, and calcined silicine, titanium dioxide, fumed silica, precipitated silica, crystalline silica, fused silica, anhydrous silicic acid, hydrated silicic acid, carbon black, ferric oxide, aluminum powder, zinc oxide, activated zinc oxide, PVC powder, PMMA powder, glass fibers, and filaments. The amount of filler used is preferably 1 to 400 parts by weight, and particularly preferably 10 to 300 parts by weight, per 100 parts by weight of polymer (A).
[0120] For the purpose of reducing the weight (specific gravity) of the cured product formed using the curable composition, balloons (hollow fillers) such as organic balloons and inorganic balloons may be added. Balloons are spherical fillers with a hollow interior. Examples of balloon materials include inorganic materials such as glass, shirasu, and silica, as well as organic materials such as phenolic resin, urea resin, polystyrene, and saran. The amount of balloon used is preferably 0.1 to 100 parts by weight, and particularly preferably 1 to 20 parts by weight, per 100 parts by weight of polymer (A).
[0121] <Adhesion-enhancing agent> Adhesion-imparting agents may be added to the curable composition. These adhesion-imparting agents may include silane coupling agents and their reaction products. Specific examples of silane coupling agents include amino group-containing silanes such as γ-aminopropyltrimethoxysilane, γ-aminopropylmethyldimethoxysilane, N-β-aminoethyl-γ-aminopropyltrimethoxysilane, N-β-aminoethyl-γ-aminopropylmethyldimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, and (2-aminoethyl)aminomethyltrimethoxysilane; γ-isocyanatetopropyltrimethoxysilane, γ-isocyanatetopropyltriethoxysilane, γ-isocyanatetopropylmethyldimethoxysilane, and α-isocyanatetomethyltrimethoxysilane. Examples include silanes and isocyanate group-containing silanes such as α-isocyanatemethyldimethoxymethylsilane; mercapto group-containing silanes such as γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, and γ-mercaptopropylmethyldimethoxysilane; and epoxy group-containing silanes such as 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, and β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane. Furthermore, the use of amino group-containing silanes is preferred for improved curability. The above adhesion-improving agents may be used individually or in combination of two or more types. Furthermore, reaction products of various silane coupling agents can also be used as adhesion-improving agents. The amount of silane coupling agent used is preferably 0.1 to 20 parts by weight, and particularly preferably 0.5 to 10 parts by weight, per 100 parts by weight of polymer (A).
[0122] <Plasticizer> Plasticizers may be added to the curable composition. Specific examples of plasticizers include phthalate compounds such as dibutyl phthalate, diisononyl phthalate (DINP), diheptyl phthalate, di(2-ethylhexyl) phthalate, diisodecyl phthalate (DIDP), and butyl benzyl phthalate; terephthalate compounds such as bis(2-ethylhexyl)-1,4-benzenedicarboxylate; non-phthalate compounds such as 1,2-cyclohexanedicarboxylic acid diisononyl ester; and aliphatic polycarboxylic acids such as dioctyl adipicate, dioctyl sebacate, dibutyl sebacate, diisodecyl succinate, and tributyl acetylcitrate. Examples include ester compounds; unsaturated fatty acid ester compounds such as butyl oleate and methyl acetylricinoleate; alkyl sulfonate phenyl esters; phosphate ester compounds; trimellitic acid ester compounds; chlorinated paraffin; hydrocarbon oils such as alkyl diphenyl and partially hydrogenated terphenyl; process oils; epoxidized soybean oil, epoxidized linseed oil, bis(2-ethylhexyl)-4,5-epoxycyclohexane-1,2-dicarbonoxylate (E-PS), epoxyoctyl stearate, epoxybutyl stearate, and epoxybenzyl stearate. Furthermore, polymeric plasticizers can be used. Specific examples of polymeric plasticizers include vinyl polymers; polyester plasticizers; polyether polyols such as polyethylene glycol and polypropylene glycol with a number average molecular weight of 500 or more, and polyethers such as derivatives obtained by converting the hydroxyl groups of these polyether polyols to ester groups, ether groups, etc.; polystyrenes; polybutadiene, polybutene, polyisobutylene, butadiene-acrylonitrile, and polychloroprene. The amount of plasticizer used is preferably 5 to 150 parts by weight, more preferably 10 to 120 parts by weight, and particularly preferably 20 to 100 parts by weight, per 100 parts by weight of polymer (A). Using plasticizer within the above range makes it easier to obtain a curable composition that can form a cured product with excellent mechanical strength while obtaining the desired effect as a plasticizer. The plasticizer may be used alone or in combination of two or more types.
[0123] <Drip-preventing agent> The curable composition may optionally contain an anti-sagging agent to prevent sagging and improve workability. The anti-sagging agent is not particularly limited. Examples of anti-sagging agents include polyamide waxes; hydrogenated castor oil derivatives; and metal soaps such as calcium stearate, aluminum stearate, and barium stearate. These anti-sagging agents may be used alone or in combination of two or more. The amount of anti-slip agent used is preferably 0.1 to 20 parts by weight per 100 parts by weight of polymer (A).
[0124] <Antioxidant> Antioxidants (anti-aging agents) can be used in the curable composition. Using antioxidants can improve the weather resistance of the cured product. Examples of antioxidants include hindered phenols, monophenols, bisphenols, diarylamines, and polyphenols. Specific examples of antioxidants are described, for example, in Japanese Patent Publication No. 4-283259 and Japanese Patent Publication No. 9-194731. The amount of antioxidant used is preferably 0.1 to 15 parts by weight, and particularly preferably 1.0 to 10 parts by weight, per 100 parts by weight of polymer (A).
[0125] <Light stabilizer> Light stabilizers can be used in curable compositions. Using light stabilizers prevents photo-oxidative degradation of the cured product. Examples of light stabilizers include benzotriazole, hindered amine, and benzoate compounds. Hindered amine compounds are particularly preferred as light stabilizers. The amount of light stabilizer used is preferably 0.1 to 10 parts by weight, and particularly preferably 0.2 to 5 parts by weight, per 100 parts by weight of polymer (A).
[0126] <UV absorber> UV absorbers can be used in the curable composition. Using UV absorbers can improve the surface weather resistance of the cured product. Examples of UV absorbers include benzophenone-based, benzotriazole-based, salicylate-based, substituted tolyl-based, and metal chelate compounds. Benzotriazole-based UV absorbers are particularly preferred. Suitable specific examples of benzotriazole-based UV absorbers include the commercially available products Chinuvin P, Chinuvin 213, Chinuvin 234, Chinuvin 326, Chinuvin 327, Chinuvin 328, Chinuvin 329, and Chinuvin 571 (all manufactured by BASF). The amount of UV absorber used is preferably 0.1 to 10 parts by weight, and particularly preferably 0.2 to 5 parts by weight, per 100 parts by weight of polymer (A).
[0127] <Property modifier> The curable composition may optionally contain property modifiers to adjust the tensile properties of the resulting cured product. The property modifiers are not particularly limited. Examples of property modifiers include alkylalkoxysilanes such as phenoxytrimethylsilane, methyltrimethoxysilane, dimethyldimethoxysilane, trimethylmethoxysilane, and n-propyltrimethoxysilane; arylalkoxysilanes such as diphenyldimethoxysilane and phenyltrimethoxysilane; alkylisopropenoxysilanes such as dimethyldiisopropenoxysilane, methyltriisopropenoxysilane, and γ-glycidoxypropylmethyldiisopropenoxysilane; trialkylsilyl borates such as tris(trimethylsilyl)borate and tris(triethylsilyl)borate; silicone varnishes; and polysiloxanes. By using property modifiers, the hardness of the cured product of the curable composition can be increased, or conversely, its hardness can be decreased to increase the elongation at break. Property modifiers may be used alone or in combination of two or more.
[0128] In particular, compounds that produce compounds having a monovalent silanol group in their molecule upon hydrolysis have the effect of reducing the modulus of the cured product without worsening the stickiness of the surface of the cured product. Compounds that produce trimethylsilanol are especially preferred. Examples of compounds that produce compounds having a monovalent silanol group in their molecule upon hydrolysis include silicon compounds that are derivatives of alcohols such as hexanol, octanol, phenol, trimethylolpropane, glycerin, pentaerythritol, and sorbitol, and produce silane monool upon hydrolysis. Specifically, examples include phenoxytrimethylsilane and tris((trimethylsiloxy)methyl)propane. The amount of property modifier used is preferably 0.1 to 10 parts by weight, and particularly preferably 0.5 to 5 parts by weight, per 100 parts by weight of polymer (A).
[0129] <Photocurable substance> Photocurable materials can be used in curable compositions. When photocurable materials are used, a film of the photocurable material is formed on the surface of the cured product, improving the stickiness and weather resistance of the cured product. Many materials of this type are known, including organic monomers, oligomers, resins, or compositions containing them. Typical materials that can be used include unsaturated acrylic compounds, polyvinyl polycinnamates, or azidized resins, which are monomers, oligomers, or mixtures thereof that have one or more acrylic or methacrylic unsaturated groups. The amount of photocurable substance used is preferably 0.1 to 20 parts by weight, and more preferably 0.5 to 10 parts by weight, per 100 parts by weight of polymer (A). Using a photocurable substance within the above range makes it easy to obtain a curable composition that forms a cured product with excellent weather resistance, flexibility, and resistance to cracking.
[0130] <Oxygen curing substance> Oxygen-curable substances can be used in the curable composition. Examples of oxygen-curable substances include unsaturated compounds that can react with oxygen in the air. Oxygen-curable substances react with oxygen in the air to form a cured film near the surface of the cured product, which prevents stickiness on the surface and the adhesion of dirt and dust to the surface of the cured product. Specific examples of oxygen-curable substances include drying oils such as tung oil and linseed oil, and various alkyd resins obtained by modifying these compounds; modified resins with drying oils, such as acrylic polymers, epoxy resins, and silicone resins; and liquid polymers such as 1,2-polybutadiene, 1,4-polybutadiene, and polymers of dienes having 5 to 8 carbon atoms, obtained by polymerizing or copolymerizing diene compounds such as butadiene, chloroprene, isoprene, and 1,3-pentadiene. These may be used individually or in combination of two or more. The amount of oxygen-curable substance used is preferably 0.1 to 20 parts by weight, and more preferably 0.5 to 10 parts by weight, per 100 parts by weight of polymer (A). When the amount of oxygen-curable substance used is within the above range, it is easy to obtain a sufficient improvement in stain resistance and it is less likely to impair the tensile properties of the cured product. As described in Japanese Patent Publication No. 3-160053, it is preferable to use the oxygen-curable substance in combination with a photocurable substance.
[0131] <<Preparation of Curable Composition>> The curable composition according to this embodiment can be prepared as a one-component type that hardens upon contact with moisture in the air after application by mixing all the components and storing them in a sealed container.
[0132] In the case of a one-component curable composition, all components are pre-mixed. Therefore, it is preferable that components containing water be dehydrated and dried before use, or that they be dehydrated during mixing by reduced pressure or other means.
[0133] (D) Curable compositions containing an epoxy compound with at least two epoxy groups per molecule are preferably stored in a sealed container at 23°C to 50°C for 1 day to 4 weeks before application (such as coating a substrate). This improves the surface hardening properties after application.
[0134] The moisture content of this heat-curable composition is preferably 100 ppm or more, preferably 120 ppm or more, preferably 140 ppm or more, and preferably 160 ppm or more. Furthermore, the moisture content of this heat-curable composition is preferably 500 ppm or less, preferably 480 ppm or less, preferably 450 ppm or less, and preferably 400 ppm or less. More specifically, the moisture content of this heat-curable composition is preferably 100 to 500 ppm, preferably 120 to 480 ppm or less, preferably 140 to 450 ppm or less, and preferably 160 to 400 ppm or less. If the moisture content is within the above range, even if the curable composition according to this embodiment does not contain a dehydrating agent, it can be used for a long period of time without hardening by storing it in a sealed container, and heat-curing properties when heated after application can also be achieved.
[0135] Furthermore, even if the moisture content at the time of preparation of the formulation is higher than the above range, the same effect can be obtained by adjusting the moisture content to within the above range by adding a dehydrating agent or the like. The moisture content at the time of preparation of the formulation (or before adding a dehydrating agent if one is added) is preferably 100 to 2000 ppm, more preferably 100 to 1500 ppm, and even more preferably 100 to 1000 ppm.
[0136] <<Manufacturing Method for Hardened Products>> Prior to curing, the curable composition according to this embodiment is shaped into a desired form by methods such as coating, casting, or filling. The curable composition, which has been coated, cast, or filled and shaped, is preferably cured under heat.
[0137] The curable composition according to this embodiment is a heat-curable type. A heat-curable type curable composition is one that hardens in a short time (for example, within 1 hour) when heated, but has an extremely slow hardening rate at room temperature and requires a long time to harden.
[0138] The conditions for heat-curing the curable composition according to this embodiment are not particularly limited, but the heating temperature is preferably 40°C or higher, more preferably 60°C or higher, and even more preferably 100°C or higher. Furthermore, the heating temperature is preferably 220°C or lower, more preferably 210°C or lower, and even more preferably 200°C or lower. More specifically, the heating temperature is preferably 40 to 220°C, more preferably 60 to 210°C, even more preferably 100 to 200°C, and even more preferably 120 to 200°C. The heating time is preferably 1 to 120 minutes, and more preferably 5 to 60 minutes. The method of heating the curable composition is not particularly limited, and hot air or infrared rays can be suitably used. In particular, the method using hot air is preferred.
[0139] The curable composition according to this embodiment undergoes a rapid and sufficient curing reaction under heated curing conditions, yielding a cured product free of internal air bubbles. Therefore, the curable composition according to this embodiment can be suitably used in applications where a short curing reaction is desired, such as in factory settings.
[0140] <<Application>> The curable composition according to this embodiment can be used as an adhesive, a sealing material for sealing work in buildings, ships, automobiles, buses, roads, home appliances, etc., a molding agent, a bonding agent, a paint, and a spray agent. Furthermore, the cured product obtained by curing the curable composition according to this embodiment is suitably used as a waterproofing material, a waterproof coating material, a vibration damping material, a vibration control material, a soundproofing material, and a foaming material. Because the resulting cured product has excellent flexibility and adhesion, the curable composition according to this embodiment is more preferably used as a sealing material or a bonding agent among the above applications. [Examples]
[0141] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.
[0142] The number-average molecular weight in the examples is the GPC molecular weight measured under the following conditions. Liquid delivery system: Tosoh HLC-8220GPC Column: Tosoh TSKgel SuperH series Solvent: THF Molecular weight: Polystyrene equivalent Measurement temperature: 40℃
[0143] The molecular weights in the examples, calculated using end-group ratios, were determined by determining the hydroxyl value according to the measurement method of JIS K 1557 and the iodine value according to the measurement method of JIS K 0070, taking into account the structure of the organic polymer (degree of branching determined by the polymerization initiator used).
[0144] The average number of silyl groups per terminal or per molecule of the polymers shown in the examples was calculated by NMR measurement.
[0145] (Synthesis example 1) A-1 Using a polyoxypropylene triol with a number-average molecular weight of approximately 4,500 as an initiator, propylene oxide was polymerized using a zinc hexacyanocobaltate grime complex catalyst to obtain polyoxypropylene (P-1) with a number-average molecular weight of 24,600 (end-group equivalent molecular weight of 17,400) and a molecular weight distribution Mw / Mn = 1.31, which has hydroxyl groups at its terminals. 1.2 molar equivalents of sodium methoxide in a 28% methanol solution were added to the hydroxyl groups of the obtained hydroxyl-terminated polyoxypropylene (P-1). After removing the methanol by vacuum defloration, an additional 1.5 molar equivalents of allyl chloride were added to the hydroxyl groups of polymer (P-1) to convert the terminal hydroxyl groups to allyl groups. Unreacted allyl chloride was removed by vacuum defloration. The obtained unpurified polyoxypropylene was mixed and stirred with n-hexane and water, and the water was removed by centrifugation. The metal salts in the polymer were removed by vacuum defloration of the hexane from the resulting hexane solution. Thus, polyoxypropylene (Q-1) having allyl groups at the ends was obtained. To 500 g of the obtained polymer (Q-1), 50 μL of platinum divinyldisiloxane complex solution (3% by weight isopropanol solution in terms of platinum) was added, and 8.5 g of trimethoxysilane was slowly added dropwise while stirring. After reacting at 100°C for 2 hours, the unreacted trimethoxysilane was removed by distillation under reduced pressure to obtain polyoxypropylene (A-1) with a number-average molecular weight of 26,200 and trimethoxysilyl groups at the ends. Polymer (A-1) was found to have an average of 0.7 trimethoxysilyl groups at each end and an average of 2.1 trimethoxysilyl groups per molecule.
[0146] (Synthesis example 2) A-2 Using polyoxypropylene glycol with a number-average molecular weight of approximately 3,000 as an initiator, polymerization of propylene oxide was carried out with a zinc hexacyanocobaltate grime complex catalyst to obtain polyoxypropylene (P-2) with a number-average molecular weight of 27,900 (end-group equivalent molecular weight of 17,700) and a molecular weight distribution Mw / Mn = 1.21, with hydroxyl groups at both ends. To the hydroxyl groups of the obtained polymer (P-2), 1.0 molar equivalent of sodium methoxide was added as a 28% methanol solution. After removing methanol by vacuum defloration, 1.0 molar equivalent of allyl glycidyl ether was added to the hydroxyl groups of polymer (P-2) and the reaction was carried out at 130°C for 2 hours. Subsequently, methanol was removed by adding 0.3 molar equivalents of sodium methoxide in a methanol solution, and then 1.8 molar equivalents of allyl chloride were added to convert the terminal hydroxyl groups to allyl groups. The obtained unpurified polyoxypropylene was mixed and stirred with n-hexane and water, and the water was removed by centrifugation. The metal salts in the polymer were removed by vacuum defloration of the hexane from the obtained hexane solution. Thus, polyoxypropylene (Q-2) having multiple carbon-carbon unsaturated bonds at the terminals was obtained. To 500 g of the obtained polymer (Q-2), 50 μL of platinum divinyldisiloxane complex solution (3% by weight isopropanol solution in terms of platinum) was added, and 9.6 g of trimethoxysilane was slowly added dropwise while stirring. After reacting the mixed solution at 90°C for 2 hours, the unreacted trimethoxysilane was removed by distillation under reduced pressure to obtain polyoxypropylene (A-2) with a number-average molecular weight of 28,000 and multiple trimethoxysilyl groups at its terminals. Polymer (A-2) was found to have an average of 1.7 trimethoxysilyl groups at each terminal and an average of 3.4 trimethoxysilyl groups per molecule.
[0147] (Synthesis example 3) A-3 To 500 g of polymer (Q-1) obtained in Synthesis Example 1, 50 μl of platinum divinyldisiloxane complex solution (3% by weight isopropanol solution in terms of platinum) was added, and 6.4 g of dimethoxymethylsilane was slowly added dropwise while stirring. After reacting at 100°C for 2 hours, the unreacted dimethoxymethylsilane was removed under reduced pressure to obtain polyoxypropylene (A-3) with a number-average molecular weight of 26,200 and dimethoxymethylsilyl groups at the terminals. Polymer (A-3) was found to have an average of 0.7 dimethoxymethylsilyl groups at each terminal and an average of 2.2 dimethoxymethylsilyl groups per molecule.
[0148] (Synthesis example 4) A-4 Using polyoxypropylene glycol with a number-average molecular weight of approximately 4500 as an initiator, propylene oxide was polymerized with a zinc hexacyanocobaltate-grime complex catalyst to obtain polyoxypropylene (P-3) with a number-average molecular weight of 27900 and terminal hydroxyl groups. To 100 parts by weight of polymer (P-3), 50 ppm of a mercaptotin-based catalyst (U-360, manufactured by Nitto Chemical Co., Ltd.) and 0.95 molar equivalents of 3-isocyanatetopropyltrimethoxysilane relative to the hydroxyl groups of the polymer were added, and a urethane reaction was carried out on the hydroxyl groups of the polymer to obtain silyl group-containing polyoxypropylene (A-4).
[0149] (Manufacturing Example 1) To 100 parts by weight of the polymer (A-1) obtained in Synthesis Example 1, 5 parts by weight of antioxidant (BASF Japan Ltd., product name: Irganox245), 160 parts by weight of surface-treated colloidal calcium carbonate (Takehara Chemical Industry Co., Ltd., product name: NEOLIGHT SP), 54 parts by weight of heavy calcium carbonate (Maruo Calcium Co., Ltd., product name: LM2200), 20 parts by weight of carbon black (Orion Engineered Carbons, product name: HIBLACK 10), 10 parts by weight of polypropylene glycol as a plasticizer (Mitsui Chemicals SKC Polyurethane Co., Ltd., product name: Actcol P-23, number average molecular weight 3000), and 40 parts by weight of Sansosizer E-PS (Shin Nippon Rika Co., Ltd., 4,5-epoxycyclohexane-1,2-dicarboxylic acid-di-2-ethylhexyl) were weighed and mixed using a spatula, and then dispersed by passing through a 3-roll mill 3 times. Subsequently, the mixture was dried under reduced pressure at 120°C for 2 hours using a planetary mixer, and the water content of the resulting mixture was measured. After cooling to below 50°C, 2 parts by weight of 3-glycidoxypropylmethyldimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KBM-402) as an epoxysilane coupling agent and 1 part by weight of acetylacetone (manufactured by Tokyo Chemical Industry Co., Ltd.) as a β-dicarbonyl compound were added and mixed. Furthermore, 2 parts by weight of trisacetylacetonate aluminum (manufactured by Kishida Chemical Co., Ltd.) was added and mixed as a curing catalyst to obtain a curable composition. The obtained curable composition was filled into a moisture-proof cartridge and sealed to obtain a one-component, heat-curable curable composition (composition 1).
[0150] (Manufacturing example 2) A one-component, heat-curable curable composition (composition 2) was obtained in the same manner as in Production Example 1, except that 2 parts by weight of 3',4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate (manufactured by Daicel Corporation, trade name: Celoxide 2021P) was further added as an epoxy compound.
[0151] (Manufacturing Example 3) A one-component, heat-curable curable composition (composition 3) was obtained in the same manner as in Production Example 2, except that vacuum drying was performed at 120°C for 3.5 hours instead of 2 hours using a planetary mixer, and the water content of the resulting composition was measured.
[0152] (Manufacturing example 4) A one-component, heat-curable curable composition (composition 4) was obtained in the same manner as the preparation of composition 1, except that 2 parts by weight of 3',4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate (manufactured by Daicel Corporation, trade name: Celoxide 2021P) was further added as an epoxy compound, and 2 parts by weight of bisacetylacetonate zinc (manufactured by Tokyo Chemical Industry Co., Ltd.) were used instead of 2 parts by weight of trisacetylacetonate aluminum.
[0153] (Manufacturing example 5) A one-component, heat-curable curable composition (composition 5) was obtained in the same manner as in Production Example 1, except that acetylacetone was not used.
[0154] (Manufacturing example 6) A one-component, heat-curable curable composition (composition 6) was obtained in the same manner as in Production Example 1, except that 0.1 parts by weight of dibutyltin bis(acetylacetonate) (manufactured by Nitto Chemical Co., Ltd., trade name: Neostan U-220H) was used instead of 2 parts by weight of aluminum trisacetylacetonate, and 2 parts by weight of 3',4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate (manufactured by Daicel Corporation, trade name: Celoxide 2021P) was used as the epoxy compound.
[0155] (Examples 1-4, Comparative Examples 1, 2) The mixtures listed in Table 1 were applied to a steel plate in a 20mm x 5mm bead shape, and then cured at 160°C for 30 minutes. After returning to room temperature (23°C), the cured material was cut with a utility knife, and the curing state and presence of air bubbles were visually inspected. The results are shown in Table 1.
[0156] Furthermore, the formulations filled into cartridges were left for one day under conditions of 23°C and 50% RH. Then, under the same conditions, the mixture was packed into 100cc disposable cups, taking care to prevent bubbles from forming. A BS-type viscometer (manufactured by Tokyo Keiki) was used with rotor No. 7 to measure the viscosity at 2 rpm (the value after 3 rotations was read), and this was defined as the initial viscosity. In addition, the formulations filled into cartridges were stored at 40°C for 14 days, and then left for one day under conditions of 23°C and 50% RH. The viscosity after storage was measured and defined as the viscosity after storage / initial viscosity × 100%.
[0157] The water content in the formulation was measured using a Karl Fischer moisture meter (EBU-610: manufactured by Kyoto Electronics Manufacturing Co., Ltd.) with Aquamicron titrator SS 3 mg (potency 2.5-3.5 mg H2O / mL, manufactured by Mitsubishi Chemical Corporation) and Aquamicron dehydrating agent CM (for water content of 0.3 mg H2O / mL or less, manufactured by Mitsubishi Chemical Corporation). The results are shown in Table 1.
[0158] [Table 1]
[0159] As is clear from Table 1, Examples 1 to 4, which contained a metal compound (B) and a chelate compound (C), showed low viscosity even after storage at 40°C for 14 days, demonstrating good heat-resistant storage stability, and also exhibited good heat-curing properties at a heating temperature of 160°C. On the other hand, Comparative Example 1 did not contain the chelating compound (C), and Comparative Example 2 used a tin catalyst instead of the metal compound (B) as a curing catalyst; both solidified in the cartridge during storage at 40°C. In these comparative examples, the catalytic activity was not sufficiently suppressed under the aforementioned heating storage conditions, resulting in poor heat-resistant storage stability.
[0160] (Examples 5-6) The formulations listed in Table 2, filled into cartridges, were left for one day at 23°C and 50% RH. Afterward, the formulations were applied to a polyethylene sheet, spread to a thickness of 3 mm, and the surface was smoothed. This time was defined as the curing start time. The curing time was measured by touching the surface with a spatula; the time until no curable composition adhered to the spatula was defined as the skinning time. Furthermore, the formulations filled into cartridges were stored at 40°C for 14 days, then left for one day at 23°C and 50% RH. The curing time was then measured again as the skinning time. The results are shown in Table 2.
[0161] [Table 2]
[0162] As is clear from Table 2, in Examples 5 and 6, when applied without storage at 40°C, it took 18 hours for the material to skin at room temperature. In Example 5, even when applied after storage at 40°C for 14 days, it still took 18 hours. However, in Example 6, which contained epoxy compound (D), the skinning time was shortened to 6 hours, indicating better curing properties.
[0163] (Examples 7-8) The surfaces of anodized aluminum sheets, electrolytically colored aluminum sheets, cold-rolled stainless steel sheets, cold-rolled steel sheets, or galvanized steel sheets were cleaned with gauze soaked in ethanol. The formulations listed in Table 3 were extruded onto these surfaces in a bead shape and lightly pressed with a micro spatula to ensure adhesion, after which they were cured at 180°C for 30 minutes. After removing the cured material and allowing it to return to room temperature (23°C), a razor blade was inserted at the interface between the cured material and the substrate, and the cured material was pulled with fingers at a 90-degree angle to the substrate to check the hand-peel adhesion. Hand-peel adhesion was determined by visually inspecting the fracture surface after the tensile test to determine whether cohesive failure (CF) or interfacial failure (AF) occurred. The results are shown in Table 3.
[0164] [Table 3]
[0165] As is clear from Table 3, Example 7 showed good adhesion to electrolytically colored aluminum sheets, cold-rolled stainless steel sheets, cold-rolled steel sheets, or galvanized steel sheets under heating conditions, and Example 8 showed good adhesion to anodized aluminum sheets in addition to the above.
[0166] (Manufacturing example 7) Instead of vacuum drying at 120°C for 2 hours using a planetary mixer, vacuum drying was performed at 120°C for 1 hour, the water content of the resulting mixture was measured, and then a one-component, heat-curable curable composition (composition 7) was obtained in the same manner as in Production Example 2, except that 4 parts by weight of molecular sieve 4A (manufactured by Union Showa Co., Ltd.) was added as a zeolite-based adsorbent.
[0167] (Manufacturing example 8) Instead of vacuum drying at 120°C for 2 hours using a planetary mixer, vacuum drying was performed at 120°C for 1.5 hours, the water content of the resulting mixture was measured, and then a one-component, heat-curable curable composition (composition 8) was obtained in the same manner as in Production Example 2, except that 4 parts by weight of molecular sieve 3A (manufactured by Union Showa Co., Ltd.) was added as a zeolite-based adsorbent.
[0168] (Manufacturing example 9) Instead of vacuum drying at 120°C for 2 hours using a planetary mixer, vacuum drying was performed at 120°C for 1.5 hours, the water content of the resulting mixture was measured, and then a one-component, heat-curable curable composition (composition 9) was obtained in the same manner as in Production Example 2, except that 4 parts by weight of molecular sieve 3A-B (manufactured by Union Showa Co., Ltd.) was added as a zeolite-based adsorbent.
[0169] (Manufacturing example 10) Instead of vacuum drying at 120°C for 2 hours using a planetary mixer, vacuum drying was performed at 120°C for 1.5 hours, the water content of the resulting mixture was measured, and then a one-component, heat-curable curable composition (composition 10) was obtained in the same manner as in Production Example 2, except that 10 parts by weight of molecular sieve 3A (manufactured by Union Showa Co., Ltd.) was added as a zeolite-based adsorbent.
[0170] (Examples 9-12) The formulations listed in Table 4 were applied to a steel plate in a 20 mm x 5 mm bead shape, and then cured at 160°C for 30 minutes. After returning to room temperature (23°C), the cured material was cut with a utility knife, and the curing state and presence of air bubbles were visually inspected. The results are shown in Table 4.
[0171] Furthermore, the formulations filled in the cartridges were left for one day under conditions of 23°C and 50% RH. Then, under the same conditions, the mixture was packed into 100cc disposable cups, taking care to prevent bubbles from forming. A BS-type viscometer (manufactured by Tokyo Keiki) was used with rotor No. 7 to measure the viscosity at 2 rpm (the value after 3 rotations was read), and this was defined as the initial viscosity. In addition, the formulations filled in the cartridges were stored at 40°C or 50°C for 14 days, and then left for one day under conditions of 23°C and 50% RH. The viscosity after storage was measured and defined as the viscosity after storage / initial viscosity × 100%.
[0172] The water content in the formulation was measured using a Karl Fischer moisture meter (EBU-610: manufactured by Kyoto Electronics Manufacturing Co., Ltd.) with Aquamicron titration solution SS 3 mg (potency 2.5-3.5 mg H2O / mL, manufactured by Mitsubishi Chemical Corporation) and Aquamicron dehydrating agent CM (for water content of 0.3 mg H2O / mL or less, manufactured by Mitsubishi Chemical Corporation). The results are shown in Table 4.
[0173] [Table 4]
[0174] As is clear from Table 4, although Examples 9-12 had a relatively high water content in the formulations, the addition of a zeolite-based adsorbent (T) resulted in good heat-resistant storage stability.
[0175] (Manufacturing Example 11) A one-component, heat-curable curable composition (composition 11) was obtained in the same manner as in Production Example 10, except that Nocrack CD (manufactured by Ouchi Shinko Chemical Industry Co., Ltd.) was used as an antioxidant instead of Irganox 245, and Actcol P-23 as a plasticizer was not used.
[0176] (Manufacturing Example 12) A one-component, heat-curable curable composition (composition 12) was obtained in the same manner as in Production Example 11, except that the amount of trisacetylacetonate aluminum was changed to 0.5 parts by weight.
[0177] (Manufacturing Example 13) A one-component, heat-curable curable composition (composition 13) was obtained in the same manner as in Production Example 12, except that polymer (A-2) obtained in Synthesis Example 2 was used instead of polymer (A-1).
[0178] (Manufacturing Example 14) A one-component, heat-curable curable composition (compound 14) was obtained in the same manner as in Production Example 11, except that polymer (A-3) obtained in Synthesis Example 3 was used instead of polymer (A-1).
[0179] (Manufacturing example 15) A one-component, heat-curable curable composition (composition 15) was obtained in the same manner as in Production Example 11, except that polymer (A-4) obtained in Synthesis Example 4 was used instead of polymer (A-1).
[0180] (Examples 13-17) Using the formulations listed in Table 5, the curing state and presence or absence of air bubbles were visually inspected after curing using the same evaluation method as in Examples 9-12. Furthermore, the viscosity increase and water content of the formulations were measured after storing them at 50°C for 14 days.
[0181] [Table 5]
[0182] As is clear from Table 5, Examples 13 to 17, using polymers (A-1) to (A-4), showed good heat-curability and heat-resistant storage stability.
[0183] (Manufacturing example 16) A one-component, heat-curable curable composition (composition 16) was obtained in the same manner as in Production Example 11, except that the amount of carbon black (manufactured by Orion Engineered Carbons, product name: HIBLACK 10) was changed to 30 parts by weight, the amount of trisacetylacetonate aluminum was changed to 0.5 parts by weight, and the amount of acetylacetone was changed to 1.5 parts by weight.
[0184] (Manufacturing example 17) A one-component, heat-curable curable composition (composition 17) was obtained in the same manner as in Production Example 16, except that 2 parts by weight of 3-glycidoxypropylmethyldiethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KBE-402) was used as an epoxysilane coupling agent instead of KBM-402.
[0185] (Examples 18-19) Using the formulations listed in Table 6, the curing state and presence of air bubbles were visually inspected using the same evaluation method as in Examples 9-12, under heating conditions of 140°C for 30 minutes, 160°C for 30 minutes, 180°C for 30 minutes, and 200°C for 30 minutes, respectively. Furthermore, the water content in the formulations was measured.
[0186] [Table 6]
[0187] As is clear from Table 6, Examples 18 and 19 showed good curing properties at heating temperatures of 160-200°C. In Example 19, which used 3-glycidoxypropylmethyldiethoxysilane as the epoxysilane coupling agent, good curing properties were also observed at a heating temperature of 140°C.
Claims
1. (A) Polyoxyalkylene polymer having a hydrolyzable silyl group as shown in general formula (1), -Si(R 1 ) 3-a (X) a (1) (In the formula, R 1 Each of these independently represents a hydrocarbon group having 1 to 20 carbon atoms, and the hydrocarbon group may contain a heteroatom. Each of these independently represents a hydroxyl group or a hydrolyzable group. a is 1, 2, or 3. (B) Metal compounds comprising at least one metal element selected from the group consisting of aluminum and zinc, and a chelate compound that is a ligand, and (C) Chelate compound, which is at least one selected from the group consisting of β-diketones and β-ketoesters. It contains, A heat-curable composition comprising 0.1 to 10 parts by weight of a metal compound (B) and 0.1 to 10 parts by weight of a chelate compound (C) per 100 parts by weight of a polymer (A).
2. Furthermore, the heat-curable composition according to claim 1 further contains (D) an epoxy compound containing at least two epoxy groups in one molecule.
3. The heat-curable curable composition according to claim 1 or 2, further containing (T) a zeolite-based adsorbent.
4. The heat-curable curable composition according to any one of claims 1 to 3, wherein the water content of the heat-curable curable composition is 100 to 500 ppm.
5. The heat-curable curable composition according to any one of claims 1 to 4, wherein the chelate compound contained in the metal compound (B) is a β-diketone or a β-ketoester.
6. A heat-curable curable composition according to any one of claims 1 to 5, wherein a in general formula (1) is 3.
7. The heat-curable composition according to claim 2, wherein the epoxy compound (D) is an alicyclic epoxy compound.
8. A heat-curable curable composition according to any one of claims 1 to 7, wherein the ratio of the total number of moles of the chelate compound and chelate compound (C) in the metal compound (B) to the number of moles of the metal element in the metal compound (B) is greater than 3.
9. The heat-curable curable composition according to claim 8, wherein the ratio of the total number of moles of the chelate compound and chelate compound (C) in the metal compound (B) to the number of moles of the metal element in the metal compound (B) is 4 or more.
10. A method for producing a heat-curable composition according to any one of claims 1 to 9, comprising the step of mixing a polymer (A), a metal compound (B), and a chelate compound (C).
11. A cured product obtained by curing a heat-curable composition according to any one of claims 1 to 9.
12. A method for producing a cured product, comprising the step of heat-curing a heat-curable composition according to any one of claims 1 to 9.
13. The method for producing a cured product according to claim 12, further comprising the step of storing the heat-curable curable composition in a sealed container at 23°C to 50°C for 1 day to 4 weeks prior to the heat curing step.
14. A method for producing a cured product according to claim 12 or 13, wherein the temperature of the heat curing step is 40 to 220°C.
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