JPH0449593B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to novel pressure sensitive adhesive compositions.
More specifically, the present invention relates to a high-pressure adhesive composition that has a long pot life at around room temperature and can be rapidly cured by being heated to high temperatures. The present inventor further found that the composition containing a polyoxyalkylene active ingredient having at least one hydrolyzable silicon group or silanol group in one molecule can be used, for example, as a sealant, a coating material, a casting material, a foam, etc. It has been found to be useful in materials, adhesives, pressure-sensitive adhesives, etc. However, it is necessary to change the curing characteristics of a polymer having a hydrolyzable silicon group or silanol group depending on the purpose and use of the cured product. For example, when a polymer having a hydrolyzable silicon group is used as a pressure-sensitive adhesive, it is difficult to balance pot life and curing speed with conventional catalyst systems, which poses a practical problem. That is, a polymer having a hydrolyzable silicon group or silanol group is
If no curing catalyst is added, it is stable for a long time and does not thicken or gel. However, once a curing catalyst is added, the polymer will remain stable even at room temperature due to the trace amount of water contained in the polymer and compounding agents. The hydrolyzable silicon groups within the polymer molecules may react, increasing the viscosity of the adhesive formulation and causing it to gel before being applied to the substrate. As a result, there are problems in that it becomes difficult to apply the adhesive to the support, the coated surface becomes uneven due to gelled substances, and the adhesive properties also become unstable. To solve the above problem, the pot life can be made to a desired length by reducing the amount of curing catalyst blended, but in that case, even if heated to high temperatures, a sufficient curing rate cannot be obtained. On the other hand, if the amount of curing catalyst added is increased, curing will occur quickly under high temperature conditions, but the pot life will be shortened, which is a major obstacle in practical use. In order to avoid such problems, a method is employed in which a curing catalyst or its solution is applied onto a support in advance and then an adhesive that does not contain the catalyst is applied, or an adhesive that does not contain a curing catalyst is applied onto the support. A method in which the catalyst or its solution is subsequently applied separately by spraying or the like may be considered, but this method has the disadvantage of complicating the process. In view of the above-mentioned circumstances, the present inventors have conducted extensive research and found that the above-mentioned problem can be solved by using a compound that has an active hydrogen group in its molecule or becomes one that has an active hydrogen group due to tautomerism. They found a solution and completed the present invention. In other words, (A) is a polymer having at least one hydrolyzable silicon group or silanol group in one molecule, which is a monomer whose main chain is essentially polyether or acrylic acid alkyl ester. A polymer obtained by polymerization, (B) a single or a mixture of two or more selected from the group consisting of alkyl alcohols, organic carboxylic acids, and keto-enol tautomeric compounds, and (C) a curing catalyst. It has been found that the pressure-sensitive adhesive composition contained as a component has a sufficiently long pot life at around room temperature and can be rapidly cured by heating to a high temperature, which is an extremely useful property from a practical standpoint. In the present invention, examples of polymers having hydrolyzable silicon groups or silanol groups in the molecule include hydrolyzable silicon at the molecular terminal and/or side chain as disclosed in JP-A-50-156599. polyoxyalkylene having group or silanol group, Japanese Patent Publication No. 49-15951, Japanese Patent Publication No. 51-28301, Japanese Patent Publication No. 54-1577, Japanese Patent Publication No. 55-46437,
Acrylic acid ester polymers or copolymers having a hydrolyzable silicon group or silanol group at the molecular end or side chain disclosed in JP-A-57-179210, and JP-B No. 45-11819, JP-B-Sho Examples include silyl-modified polymers disclosed in JP-A-49-32673, JP-A-47-1389, JP-A-57-4192, and the like. Examples of the hydrolyzable silicon group-containing polyoxyalkylene used in the present invention include
Publication No. 36319, Publication No. 46-12154, Publication No. 46-30711
Publication No. 48-36960, Japanese Unexamined Patent Application Publication No. 1983-156599
Polyoxylalkylene obtained by the method disclosed in Japanese Patent Publication No. 57-164123, etc., and structural formula (1): A polyoxyalkylene having an olefin group at the end and structural formula (2): Structural formula (3) obtained by an addition reaction with a silicon hydride compound shown by using a platinum compound as a catalyst: The hydrolyzable silicon group represented by is polyoxyalkylene having a silanol group at the end [In formulas (1), (2) and (3), R ₁ is the same or different type having 1 to 20 carbon atoms. A divalent organic group, R ₂ is H- or the same or different monovalent organic group having 1 to 20 carbon atoms, R ₃ is the same or different monovalent hydrocarbon group or triorganosiloxy group, and X is silanol. group or the same or different kind of hydrolyzable functional group, a is 0 or 1, b is 0, 1 or 2, c is 0, 1, 2 or 3, and 1≦b+
c≦4, and m represents an integer of 0 to 18]. In formulas (2) and (3), R ₃ is the same or different monovalent hydrocarbon group having 1 to 20 carbon atoms, such as an alkyl group such as methyl or ethyl, a cycloalkyl group such as cyclohexyl, or a phenyl group. selected from an aryl group, an aralkyl group such as a benzyl group, and further has the formula; (R ₄ ) ₃ Sio− (wherein R ₄ represents the same or different monovalent hydrocarbon group having 1 to 20 carbon atoms) It also includes a triorganosiloxy group represented by In formulas (2) and (3), X represents a silanol group or a different or similar hydrolyzable functional group, and examples of the hydrolyzable functional group include a halogen group, a hydride group, an alkoxy group, an acyloxy group, ketoximate group, amino group, amide group, aminooxy group, mercapto group, alkenyloxy group, etc. Specifically, the silicon hydride compound represented by formula (2) includes halogenated silanes such as trichlorosilane, methyldichlorosilane, dimethylchlorosilane, and trimethylsiloxydichlorosilane, trimethoxysilane, and triethoxysilane. , methyldimethoxysilane, phenyldimethoxysilane, alkoxysilanes such as 1,3,3,5,5,7,7-heptamethyl-1,1-dimethoxytetrasiloxane, methyldiacetoxysilane, trimethylsiloxymethylacetoxysilane, etc. acyloxysilanes, ketoximate silanes such as bis(dimethylketoximate)methylsilane, bis(cyclohexylketoximate)methylsilane, bis(diethylketoximate)trimethylsiloxysilane, dimethylsilane, trimethylsiloxymethylsilane ,1,1
Examples include, but are not limited to, hydrosilanes such as -dimethyl-2,2-dimethyldisiloxane and alkenyloxysilanes such as methyltri(isopropenyloxy)silane. In the addition reaction, after reacting the silicon hydride compound of formula (2) with the polyoxyalkylene having an olefin group of formula (1), some or all of the X groups are further replaced with other hydrolyzable groups. It can be converted into a functional group or a hydroxyl group. For example, when the X group is a halogen group or a hydride group, it is preferable to use it after converting it into an alkoxy group, an acyloxy group, an aminooxy group, an alkenyloxy group, a hydroxyl group, or the like. In formulas (1) and (3), R ₂ H- or a monovalent organic group having 1 to 20 carbon atoms is preferably H- or a hydrocarbon group, and H- is particularly preferred. R ₁ is 2 of the same or different carbon number from 1 to 20
As a valent organic group, a hydrocarbon group and a hydrocarbon group containing an ether bond, an ester bond, a urethane bond, or a carbonate bond are preferable, and a methylene group is particularly preferable. A specific method for producing polyoxyalkylene having an olefin group represented by formula (1) is the method already disclosed by the present inventors in JP-A-54-6097, or the method using epoxy oxides such as ethylene oxide and propylene oxide. It can be produced by a method of introducing an olefin group into the side chain by adding an olefin group-containing epoxy compound such as allyl glycidyl ether and copolymerizing the compound when polymerizing the compound. The main chain of the polyoxyalkylene used in the present invention essentially has the formula: -R ₅ -o- (wherein R ₅ is a divalent organic group, most of which has 1 to 4 carbon atoms. It is most effective when it is a hydrocarbon group) having chemically bonded repeating units. Specifically, R ₅ is −
CH ₂ −, −CH ₂ CH ₂ −,

【formula】

【formula】

[Formula] and - CH ₂ CH ₂ CH ₂ CH ₂ -, etc., and polyoxyalkylene may be composed of only one type of repeating unit, or polyoxyalkylene composed of two or more types of repeating units is also effective. used. especially

[Formula] is preferred. The molecular weight of polyoxyalkylene is 1500-30000
3000 can be effectively used, but preferably 3000
Those having a molecular weight of ~15,000 are preferable. Such polyoxyalkylenes are disclosed in JP-A-53-129247, JP-A-54-6097, JP-A-55-82123,
No. 55-131021, No. 55-131022, No. 55
It can also be obtained by the methods disclosed in Japanese Patent No. 137129 and No. 55-135135. These polyoxyalkylenes having a hydrolyzable silicon group or silanol group at the molecular terminal and/or side chain can be used alone or in combination of two or more. In addition, compositions obtained by polymerizing polymerizable monomers in a mixture or solution of one or more of these polymers having a hydrolyzable silicon group or silanol group in the molecule, and It is also possible to use a simple mixture of a polymer having degradable silicon groups or silanol groups and a non-silane polymer. The other non-silane polymers include alkyl ester copolymers, acrylic ester copolymers, alkyl vinyl ether polymers, alkyl vinyl ether copolymers, and ethylene that do not have a functional silyl group in the molecule. - Vinyl polymers such as vinyl acetate copolymers, polyesters, diene polymers, polysiloxanes, and the like. The alkyl alcohol used in the present invention is preferably an alcohol whose alkyl has 1 to 10 carbon atoms, such as methyl alcohol, ethyl alcohol,
Examples include n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, sec-butyl alcohol, tert-butyl alcohol, n-amyl alcohol, isoamyl alcohol, hexyl alcohol, octyl alcohol, and cellosolve. The organic carboxylic acids used in the present invention include:
Acetic acid, propionic acid, 2-ethylcaproic acid, butyric acid, caproic acid, lauric acid, palmitic acid, oleic acid, linoleic acid, malonic acid, sebacic acid,
Examples include maleic acid, phthalic acid, and tartaric acid. The ketoenol tautomer compound used in the present invention may be any compound having a methylene group and a carbonyl group on both sides of the methylene group in the molecule, but typical examples include acetylacetone, acetoacetate, and malon. Examples include acid esters. The amount of the compound (B) used is
It is preferably 0.1 to 20 parts per 100 parts (by weight, same hereinafter) of (A), and if it is less than 0.1 part, the effect of addition is difficult to exhibit. From the gist of the present invention, the addition of compound (B) is a curing catalyst.
It is preferably added before or at least simultaneously with (C). In the present invention, a curing catalyst is used for the purpose of promoting the curing reaction by condensation of hydrolyzable silicon groups, and the curing catalyst includes dibutyltin dilaurate, tin dioctylate, dioctyltin maleate, dibutyltin oxide and ester compounds. Examples include known silanol condensation catalysts such as reactants with , carboxylic acid metal salts such as alkyl titanates, amines such as dibutylamine-2-ethylhexoate, and other acidic catalysts and basic catalysts. The amount of the curing catalyst to be used is preferably 0.1 to 10 parts per 100 parts of the polymer having a hydrolyzable silicon group or silanol group in the molecule, and if it is less than 0.1 part, the catalytic effect is difficult to exhibit. In addition, in the present invention, fillers,
Compounding agents such as plasticizers, anti-aging agents, colorants, tackifier resins, adhesive agents, and organic solvents may be added, but especially when the composition of the present invention is used as a pressure-sensitive adhesive, adhesive properties Good results can be obtained by blending a tackifying resin with the purpose of improving the properties. It is desirable that the tackifying resin used in the present invention for such a purpose be well compatible with the polymer used in the present invention, and such tackifying resins include rosin-based resins (rosin, rosin ester water, etc.). rosin ester), phenol resin, xylene resin, aliphatic petroleum resin, aromatic petroleum resin, terpene resin, coumaron resin, etc., but the molecular terminals disclosed in JP-A-50-156599 etc. and (or) when using a polyoxyalkylene having a hydrolyzable silicon group or silanol group in the side chain, rosin resins (especially rosin, rosin esters, hydrogenated rosin esters), phenol resins, Modified phenolic resins such as terpene-phenolic resins and xylene resins give particularly favorable results. The amount of the tackifying resin used is 10 to 140 parts, preferably 20 to 140 parts, per 100 parts of the polymer used.
There are 120 copies. The organic solvents used in the present invention include aliphatic hydrocarbons, aromatic hydrocarbons, halogenated hydrocarbons, alcohols, ketones, esters, ethers, alcohol esters, ketone alcohols, and ether alcohols. , ketone ethers, ketone esters, and ester ethers. Furthermore, when the solvent contains a hydrolyzable ester, the stability of the composition of the present invention can be improved. Such hydrolyzable esters include trialkyl orthoformates such as trimethyl orthoformate, triethyl orthoformate, tripropyl orthoformate, and tributyl orthoformate, tetramethyl orthosilicate, tetraethyl orthosilicate, tetrapropyl orthosilicate, and orthosilicate. Tetraalkyl orthosilicates such as tetrabutyl and ethyl silicates
40, methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, γ
-methacryloxypropyltrimethoxysilane,
γ-Mercaptopropyltrimethoxysilane, γ
-glycidoxypropyltrimethoxysilane, γ
-Aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β-aminoethyl-γ-aminopropyltrimethoxysilane, etc. Formula: (R ₆ ) _4-o SiX _o (wherein, X is hydrolyzed hydrolyzable silicon compounds and parts thereof, represented by the following possible groups, R ₆ is a monovalent organic group with or without a functional group, n is an integer from 1 to 4, preferably 3 or 4) A hydrolyzate is used. The amount of the organic solvent varies depending on the molecular weight or composition of the hydrolyzable silicon group-containing polymer, and is used in accordance with the practically required concentration or viscosity of the composition. Furthermore, the composition of the present invention contains at least one silicon group per molecule bonded to a hydrolyzable group such as a silane coupling agent or a reactant thereof.
By adding a specific nitrogen-containing compound, the adhesion of the composition can be further improved. The composition of the present invention has a long pot life at room temperature and can be cured in a short time at high temperatures, so it is particularly useful as a reaction-curing pressure-sensitive adhesive. That is, the composition of the present invention has the advantage that it is free from the restriction that it must be used up immediately after preparation because there is no risk of thickening or gelling during storage for a long period of time, and it can be used on a support. Even when applying the composition to the surface of water, there is no risk of thickening in a short period of time, so there is no loss in workability. In addition, after application, the reaction progresses quickly due to moisture in the air or moisture intentionally imparted with steam, etc., and also by adding normal heat treatment, resulting in good quality silane-reactive pressure-sensitive adhesive tapes. can be obtained. The supports used in the present invention include untreated,
Widely used materials include kraft paper, Japanese paper, soft cloth, cotton cloth, cellophane, soft vinyl chloride film, polypropylene film, polyethylene film, polyester film, glass cloth, etc. that have been surface-treated with corona treatment or primer treatment. It is then cut into tapes, sheets, labels, etc. depending on the purpose and use. Note that the tapes referred to in the present invention include tapes, sheets, and labels. Hereinafter, the present invention will be explained in more detail with reference to Reference Examples, Examples, and Comparative Examples, but the present invention is not limited only to these Examples. Reference Example 1 900g of polypropylene oxide (manufactured using 90% by weight polypropylene glycol and 10% by weight polypropylene triol as starting materials) having an average molecular weight of 9000 and containing aryl ether groups at 96% of all terminals is stirred. Transfer to a pressure-resistant reaction vessel.

Add 20 g of a silicon hydride compound having the structure of [Formula], and then add a catalyst solution of chloroplatinic acid (a solution of 8.9 g of H ₂ PtCl ₆ 6H ₂ dissolved in a mixture of 18 ml of isopropyl alcohol and 160 ml of tetrahydrofuran) 0.34 ml was added, and the mixture was reacted at 80°C for 6 hours. at the end

It was confirmed by IR spectrum that polypropylene oxide having the group [Formula] was obtained. Reference Example 2 98 parts of butyl acrylate, 2 parts of trimethoxysilylpropyl methacrylate, 150 parts of toluene and 0.5 part of azopisisobutyronitrile were placed in a reaction vessel, and the mixture was heated to 110°C with stirring under a nitrogen atmosphere.
The reaction was carried out for 5 hours. The resulting copolymer solution had a solids concentration of 39.6% and a viscosity of about 70 voids (at 20°C). Reference Example 3 100 parts of the hydrolyzable silicon group-containing polyoxyalkylene obtained in Reference Example 1 was placed in a reaction vessel, and the temperature was raised to 110° C. with stirring in a nitrogen atmosphere. A mixed solution of 95 parts of acrylic butyl and 5 parts of azobisisobutyronitrile was added dropwise to this over 3 hours. Although the viscosity gradually increased, a viscous, almost transparent liquid was obtained after stirring these for another 2 hours. Example 1 To 100 g of the hydrolyzable silicon group-containing polyoxyalkylene obtained in Reference Example 1, 100 g of terbenphenol resin (YS Polyster T-115, manufactured by Yasushi Oil Co., Ltd.) and 50 g of toluene were added, and after uniformly dissolving. Furthermore, add 5g of acetylacetone to make the viscosity approximately 50.
A solution of poise (20°C) was obtained. Then, 5 g of a tin-based curing catalyst prepared from dibutyltin oxide and dioctyl phthalate was added. The composition to which the catalyst has been added is statically measured in an open state at room temperature, and the time from the time of addition of the curing catalyst until the length of the thread becomes 10 cm or more when the surface of the composition is pulled up with a spatula is measured. The pot life was allowed to stand in a sealed state at room temperature, and the storage stability was measured by measuring the time from the time of addition of the curing catalyst until the pot life became unusable due to thickening. In addition, the obtained composition was coated on a 25 μm thick polyester film using a coater so that the glue thickness after drying was 40 μm, and then the time required for drying and curing the composition using a hot air dryer at 120 ° C. Curability was measured by measuring . The dry cure of the composition was determined by touching the surface of the composition with a finger. The results are shown in Table 1. Example 2 100g of acrylic acid copolymer solution obtained in Reference Example 2
2.5 g of acetylacetone was added to the mixture, and after uniformly mixing, 5 g of the curing catalyst used in Example 1 was added. Then, in the same manner as in Example 1, pot life,
Storage stability and curing properties were measured. Results first
Shown in the table. Example 3 100g of acrylic acid copolymer solution obtained in Reference Example 2
100 g of the hydrolyzable silicon-based polyoxyalkylene obtained in Reference Example 1, 50 g of terpene phenol resin (YS Polystar T-100, manufactured by Yasushi Oil Co., Ltd.) and 7 g of acetylacetone were added to the solution, and after uniformly dissolving, Example 1 was further added. 5 g of the curing catalyst used in step 1 was added. Then, in the same manner as in Example 1, pot life,
Storage stability and curing properties were measured. Results first
Shown in the table. Example 4 After adding 4 g of acetylacetone and 5 g of the curing catalyst used in Example 1 to 100 g of the liquid obtained in Reference Example 3, pot life, storage stability, and curability were measured in the same manner as in Example 1. The results are shown in Table 1. Comparative Examples 1 to 4 In Examples 1 to 4, compositions were prepared in the same manner as in Examples 1 to 4, except that nothing was added in place of acetylacetone, and the pot life, storage stability, and curability were evaluated. It was measured. The results are shown in Table 1. Example 5 A composition was prepared in the same manner as in Example 1 except that 10 g of methanol was used instead of acetylacetone, and the pot life, storage stability, and curability were measured. The results are shown in Table 1. Example 6 A composition was prepared in the same manner as in Example 1 except that 0.8 g of 2-ethylhexanoic acid was used in place of acetylacetone, and the pot life, storage stability, and curability were measured. The results are shown in Table 1.

【table】

【table】

Claims (1)

[Scope of Claims] 1 (A) A polymer having at least one hydrolyzable silicon group or silanol group in one molecule, the main chain of which consists essentially of polyether or acrylic acid alkyl ester (B) a single or a mixture of two or more selected from the group consisting of alkyl alcohols, organic carboxylic acids, and keto-enol tautomeric compounds; C) A pressure-sensitive adhesive composition containing a curing catalyst as an active ingredient. 2. The composition according to claim 1, wherein the compound (B) is a keto-enol tautomer compound having a methylene group and a carbonyl group on both sides thereof in the molecule. 3. The composition of claim 2, wherein the keto-enol tautomeric compound is selected from the group consisting of acetylacetone, acetoacetate and malonate. 4. The composition according to claim 1, wherein the main chain of the polymer (A) is obtained by polymerizing a monomer whose main component is butyl acrylate or 2-ethylhexyl acrylate. 5 The main chain of the polymer (A) substantially has 1 to 4 carbon atoms.
The composition according to claim 1, which is an oxyalkylene polymer. 6. The composition according to claim 4, wherein the polymer (A) has a molecular weight of 3,000 to 15,000. 7. The composition according to claim 1, wherein the hydrolyzable silicon group of the polymer (A) is an alkoxysilyl group. 8. The composition according to claim 1, wherein 20 to 120 parts by weight of a compatible tackifier resin is added to 100 parts by weight of the polymer (A).