JP2000273418A - Optically polymerizable composition, moisture-hardenable type pressure-sensitive adhesive sheet and connection of member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition capable of providing a moisture- hardenable type adhesive not only excellent in initial adhesion and shape retainability but also capable of exhibiting a sufficient adhesive strength to a concrete, or the like, by including a specific crosslinkable polymer, a (meth) acrylic monomer, and the like. SOLUTION: This composition comprises (A) a crosslinkable polymer having two or more alkoxysilyl groups in the molecule, (B) a (meth)acrylic monomer having two or more (meth)acrylic groups in the molecule (e.g. urethane acrylate), (C) a silane coupling agent having amino groups [e.g. N-(2-aminoethyl)-3- aminopropylmethyldimethoxysilane], and (D) a photopolymerization initiator (e.g. 4-(2-hydroxyethoxy)phenyl). For example, the proportion of the formulation is regulated so as to be 10-100 pts.wt. component B, 0.1-10 pts.wt. component C and 0.01-10 pts.wt. component D based on 100 pts.wt. component A.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a moisture-curing type, which is normally tacky by photopolymerization, but is particularly suitable for bonding and sealing inorganic materials such as concrete and calcium silicate plates and wood. The present invention relates to a photopolymerizable composition capable of providing an adhesive, a moisture-curable adhesive sheet obtained from the composition, and a method for joining members.

[0002]

2. Description of the Related Art Conventionally, in the adhesive fixing in various fields, the emergence of a pressure-sensitive adhesive having both a high initial adhesive strength and a sufficient temporal adhesive strength and a bonding method thereof have been desired. Moisture-curable adhesives and adhesive tapes are used. As this moisture-curable adhesive tape, for example,
JP-A-63-61076 discloses a sealing material containing an acrylic polymer having an alkoxysilyl group and a polyether polymer having an alkoxysilyl group. Since such a moisture-curable adhesive or sealing material can be applied to an adherend as a viscous liquid composition, bonding of an adherend having an uneven surface such as an inorganic material or wood and sealing of a gap are performed. It is widely used because it is suitable for.

However, since this material is in a liquid state, the adhesive oozes out from the side when the members are joined, and the thickness of the adhesive layer becomes thin due to the pressure of the members, so that the peeling force cannot be exhibited even after the material is cured. There was a problem. Also,
Since it takes a long time to cure, there is also a problem in that if the processing in the next step is performed immediately after joining the members, the joined members may be displaced or peeled off.

In order to solve such a problem, Japanese Patent Laid-Open No.
JP-137137 discloses an adhesive obtained by applying a photopolymerizable composition containing a carboxyl group-containing vinyl monomer and a crosslinkable polymer having two or more alkoxysilyl groups to a substrate in addition to an acrylate monomer and photopolymerizing the composition. A tape is disclosed, and according to the description of this publication, an adhesive tape having a high initial adhesive strength and being capable of exhibiting a strong adhesive strength to an inorganic material, wood, or the like by being moisture-cured over time is obtained.

[0005]

However, in the technique described in the above-mentioned publication, although the problems such as bleeding due to the liquid pressure-sensitive adhesive are surely solved by the photopolymerization of the photopolymerizable composition, the technique of the present invention is not disclosed. According to the study by the people and others, it was necessary to further improve the bonding strength to the inorganic material or wood after moisture curing.

[0006] In view of the above problems in the field of the conventional moisture-curable adhesive, the present invention has excellent initial adhesive strength and shape retention, and is particularly suitable for inorganic materials such as concrete and calcium silicate plates. It is possible to develop a moisture-curable adhesive having water resistance and durability, which can provide sufficient adhesive strength to wood and wood, etc., and a photopolymerizable composition which can be provided by photopolymerization, and this composition. An object of the present invention is to provide a moisture-curable adhesive sheet and a method for joining members.

[0007]

In order to achieve the above object, the photopolymerizable adhesive composition of the present invention according to claim 1 comprises (a) two or more alkoxysilyl groups in a molecule. (B) a (meth) acrylic monomer having two or more (meth) acrylic groups in the molecule,
(C) a silane coupling agent having an amino group; and (d) a photopolymerizable initiator. The moisture-curable adhesive sheet according to the present invention according to claim 2 is a substantially unreacted state obtained by polymerizing the photopolymerizable composition according to claim 1 by light irradiation. Characterized by having an alkoxysilyl group of

The moisture-curable pressure-sensitive adhesive sheet according to the present invention according to claim 3 is obtained by subjecting the photopolymerizable composition according to claim 1 to photopolymerization and causing substantially no reaction on the substrate. An adhesive layer having an alkoxysilyl group in a state is formed. Furthermore, in the method for bonding members according to the present invention as set forth in claim 4, the moisture-curable adhesive sheet according to claim 2 is bonded to an adherend, and the bonding member is bonded. The method includes a step of curing the moisture-curable adhesive sheet.

Hereinafter, the present invention will be described in more detail. still,
In this specification, for example, “(meth) acryl group” indicates “methacryl group or acrylic group”. The photopolymerizable adhesive composition according to the first aspect contains a crosslinkable polymer (a) having two or more alkoxysilyl groups in the molecule. The crosslinkable polymer (a) has a polyether chain as a main chain, and includes, for example, those having an alkoxysilyl group at the terminal or side chain of an acrylic polymer, those having an alkoxysilyl group at the terminal of a polyether, and those of a polyester. Examples include those having an alkoxysilyl group at the terminal and those having an alkoxysilyl group at the terminal of the polycarbonate.

Examples of commercially available products include "Kaneka MS Polymer 20A", "Kaneka MS Polymer # 300 Series", and "Kaneka Cyril 5A01" (all manufactured by Kaneka Corporation). The alkoxysilyl groups in the crosslinkable polymer (a) are hydrolyzed by water or moisture and crosslinked to obtain a high adhesive strength. For example, when the alkoxysilyl groups adhere to an inorganic surface such as a concrete wall, the alkoxysilyl group becomes By the condensation reaction with existing metal elements such as aluminum, silicon and iron, “Si—O—
An "M" bond can be formed to increase the interfacial bond strength.

The moisture-curable photopolymerizable pressure-sensitive adhesive composition contains a silane coupling agent (c) having an amino group, and therefore has a high bonding strength with inorganic materials and wood, and has high water resistance. In addition, since the (meth) acrylic monomer (b) having two or more (meth) acrylic groups in the molecule is contained, high cohesion can be exhibited also in photopolymerization. Examples of the (meth) acrylic monomer (b) having two or more (meth) acrylic groups in the molecule include urethane acrylate, polyester acrylate, polyether acrylate, and a vinyl group graft obtained by grafting a radical polymerizable unsaturated bond to polyacrylate. Acrylates are mentioned.

In the photopolymerizable composition of the present invention, the (meth) acrylic monomer having a (meth) acrylic group includes a (meth) acrylate monomer (b) having two or more (meth) acrylic groups in a molecule. In addition, a (meth) acrylate monomer having one (meth) acryl group in the molecule may be used in an appropriate amount. Preferably, the proportion of the above (b) is 50 to 100% by weight in the total amount of both. Is done.

As the silane coupling agent (c) having an amino group, an alkoxysilane compound having an active amino group is preferably used. For example, N- (2-aminoethyl) 3-aminopropylmethyldimethoxysilane Bifunctional silane coupling agents such as N- (2-aminoethyl) 3-aminopropylmethyltrimethoxysilane
Functional silane coupling agents, compounds having primary, secondary, and tertiary amino groups in the molecule, compounds having a large number of amino groups, and compounds having an alkoxysilane moiety other than methoxy are exemplified.

As the photopolymerizable initiator (d), a photoradical polymerizable initiator is preferably used.
(2-Hydroxyethoxy) phenyl (2-hydroxy-2-propyl) ketone [manufactured by Ciba Geigy, trade name “Darocur 2959”], 2-hydroxy-2,2
-Dimethylacetophenone [manufactured by Ciba-Geigy, trade name "Darocur 1173"], 1-hydroxycyclohexylphenyl ketone [manufactured by Ciba-Geigy, trade name "Irgacure 184"], methoxyacetophenone,
Acetophenone-based initiators such as 2,2-dimethoxy-2-phenylacetophenone [trade name “Irgacure 651” manufactured by Ciba Geigy Co., Ltd.], benzoin ether-based initiators such as benzoin ethyl ether and benzoin propyl ether, benzyl dimethyl ketal and the like Ketal initiators, halogenated ketones, acylphosphine oxides, acylphosphinates, 2.4.6-trimethylbenzoyldiphenylphosphine oxide (BA
SF Company, trade name "Lucillin TPO") and the like,
These may be used alone or in combination of two or more.

Among the above photo-radical polymerizable initiators, a wavelength of 4
Those having a molecular extinction coefficient of 100 or more at 00 nm are preferred in terms of the photopolymerization reaction efficiency. The blending of each of the above components is based on 100 parts by weight of the crosslinkable polymer (a) having two or more alkoxysilyl groups in the molecule, and a (meth) acrylate monomer having a (meth) acryl group in the molecule ( b) 10 to 100 parts by weight, 0.1 to 10 parts by weight of a silane coupling agent (c) having an amino group in the molecule and having a molecular weight of 2000 or less, and 0.01 to 10 parts by weight of a photo-radical polymerization initiator (d). Preferably it is 10 parts by weight.

Further, the photopolymerizable composition of the present invention comprises a silanol condensation catalyst, a filler or extender, a chain transfer agent, a silane coupling agent having a functional group other than an amino group, a tackifier, a reactive agent, A monomer having a functional group can be added. As the silanol condensation catalyst, conventionally known ones can be used, for example, dibutyltin dilaurate, dibutyltin oxide, dibutyltin diacetate,
Dibutyltin phthalate, bis (dibutyltin laurate)
Tin catalysts such as oxide, dibutyltin bisacetylacetonate, dibutyltin bis (monoester malate), tin octylate, dibutyltin octoate, dioctyltin oxide, and titanates such as tetra-n-butoxytitanate and tetraisopropoxytitanate Examples thereof include compounds, amine salts such as dibutylamine-2-ethylhexoate, and other acidic catalysts. These can be used alone or in combination of two or more.

The tin-based catalyst is compounded in such a manner that, when the crosslinkable polymer (a) having two or more alkoxysilyl groups in a molecule is 100 parts by weight, a (meth) acryl group (meth) ) 10 acrylate monomers (b)
-100 parts by weight, molecular weight 20 having an amino group in the molecule
0.1 to 10 silane coupling agents (c)
Parts by weight of the photo-radical polymerization initiator (d)
It is preferable to use 0 parts by weight, and 0.01 to 5 parts by weight of the tin catalyst (e).

Examples of the filler include inorganic hollow fine particles such as glass balloon, alumina balloon, shirasu balloon and fly ash balloon, inorganic beads such as glass beads, silica beads, silica gel, alumina silica, fly ash and synthetic mica. Fine particles, diatomaceous earth, porous fillers such as porous silica, polymethyl methacrylate,
Acrylonitrile-vinylidene chloride copolymer, polystyrene, organic hollow microparticles made of phenolic resin, polymethyl methacrylate beads, polystyrene beads, nylon beads, styrene acrylic beads, urethane beads, silicone beads, polyethylene beads, polypropylene beads, ethylene- Organic fine particles such as beads of vinyl acetate copolymer, beads of polyethyl acrylate,
Examples thereof include cubic alumina silica, glass flakes, glass fibers, and chain clay minerals, which may be used alone or in combination of two or more.

At the time of the photopolymerization, a chain transfer agent may be added to the photopolymerizable composition for the purpose of suppressing variation in the polymerization reaction and appropriately adjusting the molecular weight of the obtained copolymer. N-dodecyl mercaptan, 2-mercaptoethanol, β-mercaptopropionic acid, octyl β-mercaptopropionate, methoxybutyl β-mercaptopropionate, trimethylolpropane tris (β-thiopropionate), butyl thioglycolate, Examples thereof include thiol compounds such as propanethiols, butanethiols, and thiophosphites, and halogen compounds such as carbon tetrachloride. These may be used alone or in combination of two or more.

If necessary, a tackifying resin may be added to the photopolymerizable composition as long as the photopolymerizability is not impaired. For example, C5 and C9 hydrogenated petroleum resins, hydrogenated Rosin resin, hydrogenated rosin ester resin, hydrogenated terpene resin, hydrogenated terpene phenol resin, hydrogenated coumarone / indene resin, disproportionated rosin resin, disproportionated rosin ester resin, polymerized rosin resin, polymerized rosin ester resin, etc. Resins having relatively few unsaturated bonds may be mentioned, and these may be used alone or in combination of two or more.

When the addition of the tackifier resin causes polymerization inhibition such as a decrease in the molecular weight or a decrease in the polymerization rate, it is necessary to appropriately adjust the addition amount of the polyfunctional vinyl monomer or the chain transfer agent.

Next, the manufacturing process conditions of the moisture-curable adhesive sheet will be described. As a basic process, a method of applying the above-described photopolymerizable composition onto a substrate such as a release sheet using a coating machine such as a roll coater, and then irradiating with light to polymerize the substrate. No.

The lamps that can be used for the light irradiation include:
Those having an emission distribution at a light wavelength of 400 nm or less, such as a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp,
Chemical lamps, black light lamps, microwave excited mercury lamps, metal halide lamps and the like,
Wavelength region effective for the decomposition of the photopolymerizable initiator (usually 330 to
(400 nm) can be efficiently emitted, and a chemical lamp is preferably used because a thick film sheet can be efficiently polymerized.

Further, the irradiation intensity of the lamp is appropriately selected depending on the performance of the target product, since the irradiation intensity of the lamp affects the degree of polymerization of the copolymer obtained from the photopolymerizable composition. For example, in the case of a cleavage type photopolymerizable initiator having a normal acetophenone group, when the irradiation intensity is low, the time until the start of the reaction varies due to inhibition of polymerization by oxygen, and a polymer having a constant polymerization degree is obtained. When the molecular weight is increased, the amount of radicals generated at the initial stage is increased, and the molecular weight is reduced, so that it is difficult to balance pressure-sensitive adhesiveness, cohesive force and stress relaxation. Is preferred.

The moisture-curable pressure-sensitive adhesive sheet comprises a (meth) acrylic monomer having two or more (meth) acrylic groups in a molecule in a composition containing a crosslinkable polymer (a) having a silyl group. Since it contains (b) and the silane coupling agent (c) having an amino group, the adhesive layer having an alkoxysilyl group in a substantially unreacted state is formed even after photopolymerization. Because of this, cross-linking via silanol groups due to moisture and the like progresses rapidly, so that initial adhesive strength and shape retention are excellent, and coarse materials such as inorganic materials such as concrete and calcium silicate plate and wood are particularly used. A sufficient adhesive strength can be exhibited even on the surface, and an adhesive layer having water resistance and durability can be formed.

According to a third aspect of the present invention, in the method for joining members, the moisture-curable adhesive sheet is attached to an adherend, and the joining member is attached. It includes a step of curing the conductive sheet, and when using an inorganic material such as concrete or calcium silicate plate or wood as the adherend or the joining member,
Especially effective.

Hereinafter, embodiments of the present invention will be described.
The numbers in the following composition mean "parts by weight".

[0028]

EXAMPLES (Example 1 and Comparative Examples 1 and 2) "Preparation of photopolymerizable composition" According to the composition shown in Table 1, various polymers (a) to (f), monomers, catalysts, etc. were placed in a glass bottle. After stirring and mixing until uniform dispersion,
Dissolved oxygen was removed by filling with nitrogen gas to prepare a photopolymerizable composition.

Specifically, a modified silicone polymer (manufactured by Kaneka Chemical Industry Co., Ltd., trade name “Kaneka MS Polymer 303”) as a crosslinkable polymer (a) is an acrylic monomer having two or more acrylic groups in the molecule ( Bifunctional urethane acrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., trade name "UA-340P") is used as b), and aminosilane (manufactured by Chisso Corporation, trade name "S320") is used as the silane coupling agent having an amino group (c). , As a photopolymerizable initiator (d), 2.4.
6-trimethylbenzoyldiphenylphosphine oxide (manufactured by BASF, trade name "Lucillin TPO") and 2
-Hydroxy-2,2-dimethylacetophenone (manufactured by Ciba-Geigy Co., trade name "Darocur 1173") manufactured by Merck, and bis (dibutyltin lauric acid) oxide (manufactured by Sankyoki Gosei Co., Ltd.) as a tin catalyst (e) And trade name "SB-65"), and butyl acrylate was used as the monofunctional acrylate (f).

[Preparation of Moisture-Curable Adhesive Sheet] The above photopolymerizable composition was coated on a release-treated surface of a 38 μm transparent polyethylene terephthalate (PET) film which had been subjected to a release treatment on one side, and then subjected to the same process. After covering the release surface with a PET film so that the exposed surface is in contact with the exposed surface, ultraviolet rays having an irradiation intensity of 5 mW / cm 2 are irradiated for 15 minutes using a chemical lamp to obtain a thickness of 1.0 ± 0.1 mm as shown in Table 1. 2
mm was obtained.

[Performance evaluation] Expression of cohesive force (taping) When the release PET on one side was peeled off after irradiation with ultraviolet rays,
It was evaluated that the pressure-sensitive adhesive sheet could be formed into a tape in a state where the pressure-sensitive adhesive sheet peeled off from the PET film without causing cohesive failure. Peel strength First, the above moisture-curable pressure-sensitive adhesive sheet was applied to a sheet having a width of 20 mm and a length of
After cutting to 0mm, peel off the PET film on one side,
Calcium silicate plate (manufactured by Japan Test Panel, width 20 mm x
After affixing to the longitudinal end of length 40mm x thickness 5mm),
The sheet was sandwiched between the same calcium silicate plates, pressed by reciprocating a 2 kg pressure roller two times at a speed of 300 mm / min, and left in a constant temperature room at 50 ° C. for 168 hours. The results of measuring the splitting adhesive strength at 180 ° C. at a pulling speed of 300 mm / min are shown in Table 1 together with the fracture mode. However, the unit is Kgf / 20mm width.

[0032]

[Table 1]

[0033]

The photopolymerizable composition according to the present invention, which contains a polyfunctional acrylate, exhibits a high cohesive force immediately after photopolymerization and can provide a sheet exhibiting sufficient handleability. Since the crosslinkable polymer (a) having two or more alkoxysilyl groups has an alkoxysilyl group in a substantially unreacted state, it exhibits sufficient wetting to the adherend.

In the composition containing the crosslinkable polymer (a) having two or more alkoxysilyl groups, the (meth) acrylic monomer (b) having two or more (meth) acrylic groups in the molecule And the silane coupling agent (c) having an amino group, the curing reaction proceeds rapidly without substantial inhibition of radical polymerization by the silane coupling agent in the photopolymerization or crosslinking reaction process. Therefore, it is excellent in initial adhesive strength and shape retention, and it can express sufficient adhesive strength especially to inorganic materials such as concrete and calcium silicate plate and wood, etc., and has good water resistance and durability. An adhesive layer having the same can be formed.

The moisture-curable adhesive sheet according to the present invention has a substantially unreacted alkoxysilyl group obtained by polymerizing the above photopolymerizable composition by irradiating it with light. Therefore, it has sufficient wettability to the adherend and, with the passage of time, the cross-linking through silanol groups progresses due to moisture in the air and the like, so that the reaction speed is high, and especially the concrete and calcium silicate plate etc. A sufficient adhesive strength can be exhibited to an adherend having an uneven surface such as equipment and wood, and an adhesive layer having water resistance and durability can be formed.

Further, the above-mentioned moisture-curable adhesive sheet is
When the adhesive layer having a substantially unreacted alkoxysilyl group is formed on the substrate,
In addition to the above effects, it has high shape stability and is easily stored as a weight body.

In the method of joining members according to the present invention, the moisture-curable adhesive sheet is attached to an adherend, and the joining member is attached. Since the step of curing the sheet is included, cross-linking via silanol groups proceeds promptly due to moisture in the air and the like, so that it can be applied to an adherend such as an inorganic material such as concrete or a calcium silicate plate or wood. In addition, it is possible to form an adhesive layer having sufficient watertightness and durability, which can exhibit sufficient adhesive strength in a favorable working environment without a displacement of the joining member.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C09J 133/04 C09J 133/04 201/00 201/00 F term (Reference) 4F071 AA31 AA53 AA67 AC16 AE02 AE06 AE17 BC01 CB06 CB08 4F100 AH03H AH06H AK25B AK25J AK42 AK51 AK51J AK52B AK52K AL05B AL06B AR00B AT00A BA02 CA30B EJ67B GB90 JB07 JB20 JB20B JL00 JL11 JL13B 4J002 BG001 CK001 CP031 EH096 EX007 EZ037 FD010 FD147 FD200 GJ01 GJ02 4J004 AA01 AA17 AB01 AB07 CA06 CC02 DB03 FA08 4J040 ED001 EE021 EL021 FA231 FA232 FA271 FA272 FA281 FA282 FA291 FA292 GA02 GA31 HB19 HD36 JA09 JB04 JB08 JB09 KA13 KA16 LA06 LA07 MA01 MA06 MA08 PA32

Claims (4)

[Claims] 1. (a) a crosslinkable polymer having two or more alkoxysilyl groups in a molecule, (b) a (meth) acrylic monomer having two or more (meth) acrylic groups in a molecule, and (c) amino A silane coupling agent having a group,
And (d) a photopolymerizable composition comprising a photopolymerizable initiator. 2. A moisture-curable adhesive having a substantially unreacted alkoxysilyl group obtained by irradiating the photopolymerizable composition according to claim 1 with light. Adhesive sheet. 3. The photopolymerizable composition according to claim 1, which is photopolymerized to form an adhesive layer having a substantially unreacted alkoxysilyl group on a substrate. Characteristic moisture-curable adhesive sheet. 4. After bonding the moisture-curable adhesive sheet according to claim 2 to an adherend and bonding a joining member, the moisture-curable adhesive sheet is cured by moisture in the atmosphere. A method for joining members, comprising the steps of: