JPS59170168A - Pressure-sensitive adhesive composition - Google Patents

Abstract

PURPOSE:A pressure-sensitive adhesive composition, containing a polymer having hydrolyzable silicon groups, etc., a compound having active hydrogen groups and a curing catalyst, having a long pot life near ordinary temperature, and curable rapidly on heating at a high temperature. CONSTITUTION:A pressure-sensitive adhesive composition containing (A) a polymer having one or more hydrolyzable silicon groups, preferably alkoxysilyl groups, in the molecule thereof, preferably a polymer having the main chain obtained by polymerizing a monomer consistig essentially of a polyether and an alkyl acrylate and 3,000-15,000 molecular weight, (B) a compound having active hydrogen groups in the molecule thereof or capable of having the active hydrogen groups by tautomerism, preferably selected from a ket-enol tautomeric compound, e.g. an alkyl alcohol and acetylacetone, acetoacetic acid ester and malonic acid ester, (C) a curing catalyst and (D) preferably 20-120pts.wt., based on 100pts.wt. component (A), tackifier resin.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a polymer (A) having at least one hydrolyzable silicon group or silanol group in one molecule and a polymer (A) having an active hydrogen group in the molecule or having an active hydrogen group due to tautomerism. Compound (B) having a hydrogen group and curing catalyst (0)
This invention relates to a novel pressure-sensitive adhesive composition containing as an active ingredient. More specifically, the present invention relates to a pressure-sensitive adhesive composition that has a long pot life at around room temperature and can be rapidly cured by being heated to a high temperature.

The present inventors have previously discovered that compositions containing polyoxyalkylene as an active ingredient having at least one hydrolyzable silicon group or silanol group in one molecule can be used as sealants, coating materials, casting materials, foaming materials, etc. It has been found that it is useful for body materials, adhesives, pressure-sensitive adhesives, etc. However, the curing properties of a polymer having a hydrolyzable silicon group or silanol group need to be changed 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, hydrolyzable silicon group or sila/-
Polymers with 1-groups are stable for long periods of time without the addition of a curing catalyst, and do not thicken or gel. The small amounts of water present can cause the hydrolyzable silicon groups within the polymer molecules to react, increasing the viscosity of the adhesive formulation and causing it to gel before being applied to the substrate.

As a result, it becomes difficult to apply the adhesive to the support,
In addition, the gelled product not only makes the coated surface uneven, but also has the problem of unstable adhesive properties.

To solve the above problem, the pot life can be made as long as desired by reducing the amount of curing catalyst blended, but in that case, even if heated to a high temperature, the degree of curing cannot be sufficiently changed. On the other hand, if the amount of curing catalyst compounded 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, there is a method in which a curing catalyst, a medium, or a solution thereof 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. After coating, a method of separately applying the catalyst or its solution by spraying or the like can be considered, but this method has the disadvantage of complicating the process.

In view of the above-mentioned circumstances, the present inventors have conducted intensive research and found that the above 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.

That is, (A) a polymer having at least one hydrolyzable silicon group or silanol group in one molecule, (B) having an active hydrogen group in the molecule or becoming to have an active hydrogen group due to tautomerism. The pressure-sensitive adhesive composition containing the compound and (0) curing catalyst as active ingredients has a sufficiently long pot life at room temperature and is extremely useful in practical terms because it can be rapidly cured by being heated to high temperatures. discovered a characteristic.

Among the polymers having hydrolyzable silicon groups or silanol groups in the molecule, for example, JP-A-50
Polyoxyalkylene having a hydrolyzable silicon group or silanol group at the molecular terminal and/or side chain disclosed in Japanese Patent Publication No. 156599, etc.
Publication No. 951, Publication No. 51-28301, Publication No. 54-1
Publication No. 577, Publication No. 55-46467, JP-A-57
Acrylic acid ester polymers or copolymers having a hydrolyzable silicon group or silanol group at the molecular end or side chain disclosed in Japanese Patent Publication No. 179210, Japanese Patent Publication No. 11819-1981, Japanese Patent Publication No. 52673-1987 Publication, JP-A-47-1589, JP-A-47-41
No. 92 discloses silyl-modified polymers or polydiorganosiloxanes containing silanol groups or hydrolyzable functional groups.

Examples of the hydrolyzable silicon group-containing polyoxyalkylene used in the present invention include Japanese Patent Publication No. 45-36319, Japanese Patent Publication No. 46-12154, and Japanese Patent Publication No. 46-30711.
Publication No. 48-56960, Japanese Unexamined Patent Publication No. 1983-15
Polyoxyalkylene obtained by the method disclosed in Publication No. 6599, Publication No. 57-164123, etc., and polyoxyalkylene having an olefin group at the end represented by the structural formula (1): , Structural formula (2): Polymer having a hydrolyzable silicon group or silanol group at the terminal, represented by Structural formula (3) obtained by an addition reaction using a platinum-based compound as a catalyst, with a silicon hydride compound represented by Structural formula (2): oxyalkylene, etc. [In formulas (1), (2) and (3) above, R is H- or the same or different divalent organic group having 1 to 20 carbon atoms, R2 is H- or the same or different monovalent organic groups having 1 to 20 carbon atoms, R3 is the same or different monovalent hydrocarbon group or triorganosiloxy group, and X is a silanol group or the same or different hydrolyzable functional group, a is 0 or 1, b is 0.1 or 2.0 is 0.1.2 or 6, and 1
≦b+c≦4, and m represents an integer of 0 to 18].

In formulas (2) and (3), R3 is a prime number of 1 to 20
selected from the same or different monovalent hydrocarbon groups, such as alkyl groups such as methyl and ethyl, cycloalkyl groups such as sifrehexyl, aryl groups such as phenyl group, aralkyl groups such as benzyl group, etc. 1, and the formula: % Formula % (In the formula, R4 is the same or different 1 having 1 to 20 carbon atoms
It also includes a triorganosiloxy group represented by (representing a valent hydrocarbon group). Also, in equations (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, hytride group, alkoxy group, acyloxy group, ketoximate group, amino group, and amide group. ,
Examples include aminooxy group, mercapto group, and alkenyloxy group. Specifically, the silicon hydride compound represented by the formula (2) includes halogenated silanes such as -trichlorosilane, methyldichlorosilane, dimethylchlorosilane, and trimethylsiloxymethylsilane, trimethoxysilane, triethoxysilane, Methyldimethoxysilane, phenyldimethoxysilane, 1, 5.5.5.5.
7. Alkoxysilanes such as 7-hebutamethyl-1,1-dimethoxytetrasiloxane, acyloxysilanes such as methyldiacetoxysilane, trimethylsiloxymethylacetoxysilane, bis(dimethylketoximate)methylsilane, bis(cyclohexylketoxymate) ketoximate silanes such as dimethylsilane, trimethylsiloxymethylsilane, bis(diethylketoximate)trimethylsiloxysilane,
Examples include, but are not limited to, hydrosilanes such as 1,1-dimethyl-2,2-dimethyldisiloxane and alkenyloxysilanes such as methyltri(isopropenyloxy)silane.

In the addition reaction, after the silicon hydride compound of formula (2) is reacted with the polyoxyalkylene having an olefin group of formula (1), some or all of the X groups are further reacted with other hydrolyzable groups. It can be converted into a functional group or a hydroxyl group. For example, when the ), R8 is preferably H-, a cuff which is a monovalent organic group having 1 to 20 carbon atoms, n-, or a hydrocarbon group, and more preferably H-.

R groups are the same or different divalent organic groups having 1 to 20 carbon atoms, preferably a hydrocarbon group and a hydrocarbon group containing an ether bond, an ester bond, a urethane bond, or a carbonate bond, and a methylene group is particularly preferable. . A specific method for producing polyoxyalkylene having an olefin group represented by the 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. The main polyoxyalkylene used in the present invention can be produced by a method in which an olefin group-containing epoxy compound such as allyl glycidyl ether is added and copolymerized to introduce an olefin group into the side chain during polymerization of the compound. tHf, essentially a chemical having the formula: %Formula % (where R5 is a divalent organic group, but is most effective when the majority are hydrocarbon groups having 1 to 4 carbon atoms) It has repeating units that are linked together. R5 may specifically consist of only one type of repeating unit, or polyoxyalkylene consisting of two or more types of repeating units is also effectively used. The molecular weight of polyoxyalkylene is 1,500 to 50,000
can be effectively used, but preferably 6000~
One having a molecular weight of 15,000 is preferable. Such polyoxyalkylenes are disclosed in JP-A-53-129247, JP-A-54-6097, JP-A-55-82123, JP-A-55-1!11021, and JP-A-55-1310.
Publication No. 22, Publication No. 55-157129, Publication No. 55-1
The method disclosed in Japanese Patent No. 35135 can also be used.

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 a solution of one or more types of polymers having hydrolyzable silicon groups or silanol groups in the molecules, and It is also possible to use a simple mixture of a polymer having hydrolyzable silicon groups or silanol groups and a non-silane polymer.

The other non-silane polymer is an acrylic ester that does not have a functional silyl group in its molecule.

Polymers, vinyl polymers such as acrylic acid ester copolymers, alkyl vinyl ether copolymers, alkyl vinyl ether copolymers, and ethylene-vinyl acetate copolymers, polyesters, diene polymers, polysiloxanes, and the like.

The alkyl alcohol used in the present invention is preferably an alcohol in which the alkyl has 1 to 10 carbon atoms, such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, and 8eC-butyl alcohol. ,
tert-butyl alcohol, n-amyl alcohol,
Examples include isoamyl alcohol, hexyl alcohol, octyl alcohol, and cellosolve.

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, maleic acid, and phthalic acid. Examples include acids and tartaric acid.

The keto-enol 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 and acetoacetate. , matetraphosphate, etc. The amount of the active hydrogen group or the compound (B) that has an active hydrogen group due to tautomerism is 100 parts (parts by weight) of the polymer (A).
The amount is preferably 0.1 to 20 parts (the same applies hereinafter), and if it is less than 0.1 part, the effect of addition is unlikely to be exhibited.

From the gist of the present invention, the addition of compound (B) is based on the curing catalyst (0
) is preferably added before or at least at the same time.

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 used is 0.1 parts per 100 parts of the polymer having a hydrolyzable silicon group or silanol group in the molecule.
It is preferred to use ~10 parts and 0.1. If the amount is less than 100%, the catalytic effect is difficult to exhibit.

In addition, in the present invention, fillers, plasticizers,
Compounding agents such as anti-aging agents, colorants, tackifier resins, adhesion promoters, and organic solvents may be added, but in particular, when the composition of the present invention is used in a pressure-sensitive adhesive, the purpose is to improve adhesive properties. Good results can be obtained by adding a tackifier resin. 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, Hydrogenated rosin esters), phenolic resins, modified phenolic resins such as terpene-phenol resins, xylene resins, aliphatic petroleum resins, aromatic petroleum resins, terpene resins, and coumaron resins. When using a polyoxyalkylene having a hydrolyzable silicon group or silanol group at the molecular end and/or side chain as disclosed in Japanese Patent No. 156599, rosin-based resins (especially rosin, Modified phenolic resins such as rosin esters (rosin esters, hydrogenated rosin esters), phenolic resins, terpene-phenolic resins, and xylene resins give particularly favorable results.

The amount of these tackifying resins used is 10% of the polymer used.
10 to 140 parts to 0 parts, preferably 20 to 120 parts
Department.

The organic solvents used in the present invention include aliphatic hydrocarbons, aromatic hydrocarbons, halogenated hydrocarbons, alcohols, ketones, esters, ethers, alcohol esters, ketone alcohols, ethers, Examples include 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 orthotrialkyls such as trimethyl orthoformate, tributyl orthoformate, tripropyl orthoformate, and tributyl orthoformate, tetramethyl orthosilicate, tetraethyl orthosilicate, tetrapropyl orthosilicate, and orthosilicate. Tetraalkyl orthosilicate and ethyl silicate such as tetrabutyl 4o1 methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane , γ-methacryloxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, r-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, β-aminoethyl-γ- Formula of aminopropyltrimethoxysilane etc.: %Formula% (wherein, X is a hydrolyzable group, R6 is a monovalent organic group containing or not containing a functional group, n is an integer from 1 to 4,
Preferably, hydrolyzable silicon compounds represented by 6 or 4) and their partial hydrolysates are 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, by adding a silane coupling agent or a nitrogen-containing compound having at least one silicon group bonded to a hydrolyzable group in one molecule, such as a silane coupling agent or a reactant thereof, to the composition of the present invention. It can be used to improve the adhesion of objects.

The composition of the present invention has a long pot life at around room temperature, and hardens 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 being prepared, since there is no risk of thickening or gelling during storage for a long time.
Moreover, even when the composition is coated on a support, there is no risk of thickening in a short period of time, so the workability is not impaired in any way. 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. You can wander around.

Supports used in the present invention include kraft paper, Japanese paper, soft cloth, cotton cloth, cellophane, soft vinyl chloride film, polypropylene film, polyethylene film, polyester film, untreated, surface-treated paper such as corona treatment or primer treatment, Conventionally used materials such as glass cloth are widely used, and are 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 Polypropylene oxide with an average molecular weight of 9000, containing allyl ether groups at 96% of all terminals (produced using 90% by weight of polypropylene glycol and 10% by weight of polypropylene triol as starting materials) 900 ．． Transfer to a pressure-resistant reaction vessel equipped with a stirrer.

Silicon hydride compound 209 having the structure H-5i(OCH3)2- was added, and then a catalyst solution of chloroplatinic acid (H2P
tC! ! A solution of 8.92 of 6.6H20 dissolved in a mixture of 18 mz of isopropyl alcohol and 160 ml of tetrahydrofuran) 0, 34 mz was added and then heated to 80°.
The reaction was carried out at C for 6 hours.

It was confirmed by spectroscopy that pyrene oxide had been changed.

Reference Example 2 98 parts of butyl acrylate, 2 parts of trimethoxysilylpropyl methacrylate, 150 parts of toluene, and 0.5 part of azobisisobutyronitrile were charged into a reaction vessel, and the mixture was heated at 110 oO without stirring under a nitrogen atmosphere. The reaction was carried out for 5 hours. The obtained copolymer solution had a solid content concentration of 69.6%.
The viscosity was approximately 70 poise (2000).

Reference Example 6 100 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 11,000 ℃ while stirring in a nitrogen atmosphere. A mixed solution of 95 parts of acrylbutyl 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, 1009 terpene phenol resin (YS Polystar'r-115, manufactured by Yasushi Oil Co., Ltd.) and 50 toluene were added, and after uniformly dissolving, Acetylacetone 5. to a viscosity of approximately 50 voices (2000
) was obtained. Next, a tin-based curing catalyst prepared from dibutyltin oxide and dioctyl phthalate5. The composition to which the catalyst has been added is allowed to stand still in an open state at room temperature, and the length of the thread when the surface of the composition is pulled up with a spatula is 100 m or more. The pot life was determined by measuring the time, and the pot life was determined by allowing the pot to stand still in a sealed state at room temperature, and the storage stability was determined by measuring the time from the time when the curing catalyst was added until the pot became unusable due to thickening. Further, the obtained composition was coated on a polyester film with a thickness of 25 μm using a coater so that the glue thickness after drying was 40 μm, and then the composition was dried and cured using a hot air dryer at 120°0. Curability was measured by measuring time.

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 Acrylic acid copolymer solution obtained in Reference Example 2 100. and acetylacetone 2.5. were added and mixed uniformly, and then the curing catalyst 5. used in Example 1 was added. added. Then, pot life, storage stability, and curability were measured in the same manner as in Example 1. The results are shown in Table 1.

Example 6 To 1oO7 of the acrylic acid copolymer solution obtained in Reference Example 2, 100 g of the hydrolyzable silicon group-containing polyoxyalkylene obtained in Reference Example 1, and terpene phenol resin (YS Polyster T) were added.
-100, cheap crude oil) 50. and acetylacetone 7 were added and dissolved uniformly, and Example 1
5 g of the curing catalyst used in step 1 was added. Then, pot life, storage stability, and curability were measured in the same manner as in Example 1. The results are shown in Table 1.

Example 4 4, and the curing catalyst used in Example 1 5. was added, and the 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 times 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 In Example 1, 0.8% of 2-ethylhexanoic acid was used instead of acetylacetone. A composition was prepared in the same manner as in Example 1 except that the composition was used, and the pot life, storage stability, and curability were measured. The results are shown in Table 1.

Chapter 1 Table

Claims (1)

[Scope of Claims] 1 (A) a polymer having at least one hydrolyzable silicon group or silanol group in one molecule; (B) a polymer having an active hydrogen group in the molecule or having active hydrogen due to tautomerism; A pressure-sensitive adhesive composition containing a compound having a group and (C) a curing catalyst as active ingredients. 2. The composition according to claim 1, wherein the compound (B) is a single compound or a mixture of two or more selected from the group consisting of alkyl alcohols, organic carboxylic acids, and keto-enol tautomeric compounds. 6. The composition according to claim 1, wherein the compound (B) is a keto-enol tautomer compound having a methylene group in the molecule and carbonyl groups on both sides thereof. 7. The composition of claim 6, wherein the keto-enol tautomeric compound is selected from the group consisting of acetylacetone, acetoacetate and malonate. 5. The composition according to claim 1, wherein the main chain of the polymer (A) is obtained by polymerizing a monomer whose main component is polyether or acrylic acid alkyl ester. 6. 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. 7. The composition according to claim 1, wherein the main chain of the polymer (A) is substantially an oxyalkylene polymer having 1 to 4 carbon atoms. 8 The molecular weight of the polymer (A) is 6,000 to 15,000
The composition according to claim 6, which is 9. The composition according to claim 1, wherein the hydrolyzable silicon group of the polymer (A) is an alkoxysilyl group. 10. 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).