JPH0415280A - Photosetting adhesive - Google Patents

Abstract

PURPOSE:To obtain a photosetting adhesive which can join not only transparent materials but also translucent materials readily and rapidly by compounding a radical-polymerizable vinyl compound, alpha-diketone and a specific sensitizer. CONSTITUTION:A radical-polymerizable vinyl compound [e.g. 2-hydroxyethyl (meth)acrylate], alpha-diketone (e.g. camphor quinone) and a sensitizer of the formula (wherein Q<1> and Q<2> each independently represent a dialkylamino group being linked to the o-, m- or p-position with respect to the carbonyl group) [e.g. 4,4'-bis(diethylamino)benzophenone] are compounded to obtain a photo-setting adhesive. This adhesive can be cured not only by exposure to UV rays but also by exposure to visible rays, and therefore, it can exhibit higher sensitivity and attain higher adhesive strength when employed in joining translucent materials which do not transmit UV rays and transmit only visible rays, ceramics such as alumina and silica, and plastics containing a pigment or a ceramic filler.

Description

[Detailed description of the invention]

(a) Purpose of the invention [Field of industrial application] The present invention is directed to a photo-curing adhesive used for bonding, sealing, sealing, or fixing mating parts of metal parts, ceramic parts, and plastic parts. It's about uni. 2. Conventional technology; Photocurable adhesives are made by blending a photopolymerization catalyst into a composition containing a radically polymerizable vinyl compound as a main component. They do not cure while shielded from light and do not last for long periods of time. It is a curable composition that is stable but can be easily polymerized and cured by irradiation with light such as ultraviolet rays. It goes without saying that this type of photo-curing adhesive is required to be cured by irradiation with light, and in particular to be cured quickly by light of a low technical level. These conventional photocuring adhesives are often used to bond transparent materials with good light transmittance, such as glass, but they are also used to bond transparent materials with good light transmittance, such as glass. When gluing translucent materials such as plastic materials containing ceramic fillers, the energy and additionally the amount of light transmitted through these materials is low, while the sensitivity of the adhesive to light is low; It is not practical. Due to this fact, when bonding translucent materials, epoxy adhesives such as SGA are used, but epoxy adhesives require two-component heating and curing by heating at around 100°C. Also, in the case of SGA, it can be cured at room temperature, but like epoxy adhesives, it requires heating of two parts, and adhesive curing for nearly an hour is required to obtain practical strength. It is. As described above, conventional adhesives capable of bonding translucent materials have the problem of low bonding workability and low bonding speed. S Problems to be Solved by the Present Invention] The present invention aims to achieve practical adhesive strength not only for transparent materials but also for bonding translucent materials by increasing the sensitivity of the adhesive to light. It is an object of the present invention to provide a photocurable adhesive which does not require two-liquid warming, high-temperature heating, or long-term adhesive curing, and which has excellent adhesive workability and adhesive speed. (b) Structure of the Invention [Means for Solving the Problems] In order to solve the above problems, the present inventors have made intensive studies and found that by including a specific photopolymerization initiator and sensitizer, It was discovered that an adhesive with high sensitivity to light can be obtained, and the present invention was completed. That is, the present invention is a photocurable adhesive comprising the following components A, B, and C. A: Radically polymerizable vinyl compound B: α-diketone C: Sensitizer [l] represented by the following formula (I) (However, the group Q1 and the group Q2 are independently o, m with respect to the carbonyl group. or dialkylamino groups that are the same or different from each other bonded to the 2-position.] Details of each component constituting the adhesive composition of the present invention will be described below.In this specification, acrylate and/or methacrylic acid is expressed as (meth)acrylate, and acrylic acid and/or methacrylic acid is expressed as (meth)acrylic acid. <Radical polymerizable vinyl compound> Radical polymerizable vinyl compound that is component A of the adhesive of the present invention. is not particularly limited as long as it is a compound having a radically polymerizable vinyl group in its molecule. Specific examples of radically polymerizable vinyl compounds include the following: Vinyl compound ■] This is a (meth)acrylate represented by the following formula: R'O CH2= C-C-0-R2, -■ In the formula, R' represents hydrogen or -CH, and RzB has 2 carbon atoms. In the linear or branched alkyl group of ~4, it represents a substituted alkyl group in which - or two or more hydrogen atoms are replaced with a 10H group and/or a halocane atom. (Meta) represented by the above general 2) Preferred specific examples of acrylate-1- include 2-hydroquinoethyl (methacrylate, 2-hydroquinopropyl (meth)acrylate, 2-dihydroquinoethyl (meth)acrylate, 3-chloro-2hydroxopropyl There are (meth)acrylates, etc. [Vinyl compound ■: This is a (meth)acrylate represented by the following formula 0. R'O(-Rco"j R':; CH2=C-C-11 In the formula 1112, R3 represents hydrogen, -CH,, CzHs CH, OH or OR'; 1 cHz-o-c-c=cHz, and in the formula, R4 represents hydrogen, OH1 C-C=CH2 ■ Diglycerol di(meth)acrylate, glycerin tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, di-glycerol tetra(meth)acrylate, etc. [Vinyl compound ■: This is It is a (meth)acrylate represented by the following formula 0. 0-C-C=CH2, m represents an integer of 1 to 8, n represents an integer of 1 to 2°, and P represents O or 1. Preferred specific examples of the (meth)acrylate represented by the above general formula (■) include diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, and 1,2-propylene. Ge5 nocol di(meth)acrylate, dipropylene glycol di(meth)acrylate, polyethylene glycol di(methacrylate), where R5 and R4 represent hydrogen or an alkyl group of 01 to C, and R7 and Rs represent C2 to C , and m represents an integer of 1 to 10. Preferred specific examples of the (meth)acrylates represented by the above-mentioned general No. 2.2-bis(4-methacryloquinetriethoxyphenyl)propane, 22-bis(4-acryloquinopentaethoxyphenyl)propane, 2.2-bis(4-methacryloquinehexaethquinphenyl)propane, 22-Heath (4
-acryloxybutaethoxyphenyl)propane, 2
．． 2-bis(4-methacryloquine octaethoxyphenyl)propane, 2.2-bis(4-acryloxydipropoxyphenyl)propane, 2.2-bis(4-methacryloquinotriproboxophenyl)propane, 22- Bis(4-acryloxydibutoxyphenyl)propane, 2
．． 2-bis(4-methacryloquine octabutoxyphenyl)propane, 2-(4-methacryloxysheddoquinophenyl)-2-(4-methacryloquine triethoxy/phenyl)propane and 2(4-acryloxydipropoxyphenyl) )-2-(4-acryloxytriethquinphenyl)propane and the like. [Vinyl Compound (2)] This is (meth)acrylate-F shown by (2) below. ■ In the formula, R' represents hydrogen or a C1 to C4 hydrocarbon group,
n represents 0 or an integer of 1 to 1O. Preferred specific examples of the (meth)acrylate represented by the above general 2〇 include dicyclopentenyl (meth)acrylate, dicyclopentenyloxomethyl (meth)acrylate, dicyclopentenyloxomethyl (meth)acrylate, and dicyclobentenyl Examples include ochinbropyr (meth)acrylate. V vinyl compound@coThis is a (meth)acrylate represented by the following formula 0. R'O I CH,=C-C-0R,. (2) In the formula, R16 is hydrogen or an alkyl group of C5 to C1@, or a cycloalkyl group of C3 to (zo), a phenyl group, a tetrahydrofurfuryl group, or a group thereof (,,0
2G represents an alkyl group. Preferred specific examples of the (meth)acrylate represented by the above general formula (1) include (meth)acrylic acid, methyl (meth)acrylate, cyclohexyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, 2-
Examples include ethylhexyl (meth)acrylate, phenyl (meth)acrylate, and benzyl (meth)acrylate. [Vinyl Compound ■] This is a (meth)acrylate represented by the following formula 0. R'OOH CH□=C-C-0-R,, -0-R,□ -----
1 In the formula 0, RII is a hydrocarbon group of 02 to CIl+, R
1□ represents a C1 to C11 hydrocarbon group. Preferred specific examples of the (meth)acrylates represented by the above general 2〇 include 2-hydroquine-3=phenoxypropyl (meth)acrylate, cyclohexanoxy-β
-Hydroquinepropyl (meth)acrylate, tetrahydrofurfuroxy-β-hydroxypropyl (meth)acrylate, nonyloxy-β-hydroxypropyl (meth)acrylate, and the like. 5-hinyl compound (1) This is a (meth)acrylate represented by the following formula 0. R100 11j CH, = C-C-0-CH, -C-0-R, ff・0 In the formula, RI3 is a Cl-C2e' alkyl group, a vinyl group,
Indicates an aryl group or an alkoxyalkyl group. As a preferable specific example of the (meth)acrylate represented by the above general 2〇, methoxycarbonylmethyl (meth)
Examples include acrylate, ethoxycarbonylmethyl (meth)acrylate, heptoquinocarbonylmethyl (meth)acrylate, and isopropoxycarbonylmethyl (meth)acrylate. U vinyl compound (1) This is a (meth)acrylate shown in (2) below. (2) In the formula, R14 represents a C1-C2° hydrocarbon group, m is an integer of 1-10, and n is 1 or 2. [Vinyl compound (■)] This is a (meth)acrylate shown by (2) below. In the formula, m is an integer of 1 to 10, and n is l or 2. Preferred specific examples of the (meth)acrylates represented by the above-mentioned general 2〇 or There are meta)acrylates, etc. [Other radically polymerizable vinyl compounds: In addition to the above radically polymerizable vinyl compounds, component A of the present invention includes isobonyl (meth)acrylate, hydrogenated dicyclopentadienyl di(meth)acrylate, vinyl acetate, and propion. Vinyl esters such as acid vinyl; vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, and cyclohexyl vinyl ether; alkenylhenzenes such as styrene, vinyltoluene, α-methylstyrene, chloromethylstyrene, and stilhenzene; other N-vinylpyrrolidone, etc. be. As component A in the present invention, one type or a mixture of two or more of the above radically polymerizable vinyl compounds can be used. α-diketone> α-diketone, which is the B component of the adhesive of the present invention, is
It absorbs light in the visible region and functions as a photopolymerization initiator, and those represented by the following general formula Cm are particularly preferred. X-C-C-Y -------------[n]
(However, X and Y are the same or different substituted or unsubstituted alkyl groups, alkenyl groups, or aryl groups, and X and Y may be bonded to each other to form a cyclic structure.) Preferred specific examples of α-diketones Examples include camphorquinone, hensyl, alpha-naphthyl, acetonaphcene, p,
ρ゛-Dimethquinbenzyl p, p'-dichlorohensylbiacetyl, butanedione, pentanedione, 1.2
-phenanthrenequinone, 1,4-phenanthrenequinone, 3,4-phenanthrenequinone, 9,10-phenanthrenequinone and naphthoquinone, and particularly preferred α-diketones include camphorquinone, hensyl and butanedione. As the daily ingredient in the present invention, one or a mixture of two or more of the above α-diketones can be used. The preferred blending ratio of component B is that it acts as a photopolymerization catalyst,
It may be a catalytic stoichiometric amount sufficient to impart photocurability to the composition, and varies depending on the radically polymerizable compound used, but from 0.01 to 100 parts by weight (hereinafter simply referred to as parts) of component A. 20 parts, more preferably 0.905 to 10 parts. Sensitizer> In the present invention, component C used as a sensitizer in combination with α-diketone is represented by the following general formula [1]. (However, group Q1 and group Q2 are dialkylamino groups that are the same or different from each other and are bound to the carbonyl group and independently bonded to the o, m or 1 position.) In the above general formula [■] Preferred dialkylamino groups are dimethylamino, diethylamino, dipropylamino, dibutylamino, methylethylamino and other di-lower alkylamino groups, and preferred specific examples of component C include 4.4'- Bis(diethylamino)
Hensifhenone, 2,4゛-bis(diethylamino)hensiphenone, 3.4゛-bis(diethylamino)hensiphenone, 2.2゛-bis(diethylamino)hensiphenone, 2.3゛-bis(diethylamino)hensiphenone, 4,4゛-bis(dimethylamino)hensiphenone, 2.2'-bis(dimethylamino)hensiphenone, 2.4'-bis(dimethylamino)hensiphenone, 4.4bis(dipropylamino)hensiphenone, 2
゜4゛-bis(dipropylamino)penduphenone, 4
．． 4'-bis(dibutylamino)hensiphenone, 2.
Examples include 4'-bis(dibutylamine)hensiphenone, 4-methylethylamino-4'-dimethylaminobenzophenone, and 4-methylethylamino-2'-dimethylaminohensiphenone. Although it is not clear how the sensitizer (component C) in the present invention acts during polymerization, the present inventors have discovered that the sensitizer absorbs light in the near-ultraviolet to visible range and excited α −
It is believed that this promotes the decomposition of diketones and the generation of radicals. As the sensitizer, one or a mixture of two or more amine compounds satisfying the structure of the above general formula CI) can be used. The preferred blending ratio of component C in the present invention is a catalytic stoichiometric amount sufficient to act as a sensitizer and impart photocurability to the adhesive (although it varies depending on the radically polymerizable compound used, 0.01-20 per 100 parts of ingredient
parts, more preferably 0.05 to IO parts. Desired Additive Components> In addition to the components A, B, and C described above, various substances may be added to the adhesive of the present invention for various purposes. For example, nitro Compounds, nitroso compounds, and quinones, dyes and pigments for coloring, thixotropic agents such as silica for imparting thixotropy, acrylic resins, urethane resins, epoxy resins, silica, etc. for thickening and weighting purposes. can be combined with each other. Furthermore, for the purpose of imparting thermal polymerizability or anaerobic polymerizability to the adhesive of the present invention, an organic peroxide may be added.
For the purpose of increasing photocurability in the ultraviolet 1iA tI region,
A conventionally known ultraviolet polymerization initiator can also be blended. The adhesive composition of the present invention can be easily prepared by mixing and dissolving the components described above at room temperature or under heating. <Adhesive method> To perform adhesion using the adhesive of the present invention, after applying the adhesive of the present invention to one transparent or translucent adherend, lightly rub the other adherend to be adhered. The adhesive may be crimped and an effective amount of light such as ultraviolet rays or visible light may be irradiated through the adherend. The light irradiation source is not particularly limited as long as it can irradiate an effective amount of light, and any irradiation source that can be used on a boat may be used, such as the following irradiation sources. Carbon arc, mercury vapor arc, fluorescent lamp, argon glow lamp, incandescent lamp, halogen lamp, high pressure mercury lamp, ultra-high pressure mercury lamp, flash U lamp, high pressure mercury lamp, low pressure mercury lamp, deep UV lamp, xenon short lamp, High output water-cooled xenon lamps, xenon flash lamps, and metal halide lamps such as gallium halide lamps or thallium halide lamps. [Examples and Comparative Examples] Hereinafter, the present invention will be explained in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. The surroundings of the mixing container are covered with aluminum foil to block light, and the specified photopolymerization catalyst and sensitizer are blended with 100 parts of the specified radically polymerizable vinyl compound, and the mixture is mixed and stirred while heating at 80°C. A photocurable adhesive having the composition shown in Table 1 below was prepared using a liquid mixture. In addition, 2-2 used when preparing the adhesive of Comparative Example Seed 1
Hydroxy-2-methyl-propiophenone is commonly used as a polymerization initiator by UV irradiation.

[Evaluation of photocuring adhesiveness]

The various photocurable adhesives listed in Table 1 are
A halogen lamp (IIOV/100
w/LW, manufactured by Ushio Inc.] for 60 seconds to cure the adhesive. The illuminance of transmitted light at a specific measurement wavelength when irradiating light from a halogen lamp through the test piece is:
As shown in Table 2 below, the light that passed through the test piece contained almost no ultraviolet rays and only weak visible rays. (Test piece) Product name Polybutylene terephthalate [manufactured by Nippon Test Panel Industries Co., Ltd.] Mr. I Juranefukus 2002 (white) Table 2 (
(Illuminance of light transmitted through the test piece) After curing the adhesive as described above, the tensile shear adhesive strength and bending adhesive strength were measured according to JIS-6850 and JIS K-685, respectively.
Measured according to 6. The results were as shown in Tables 3 and 4 below. Table 3 (Tensile shear adhesive strength measurement results) Dimensions 2.0m
s (thickness) x25m5 (width) x1005m+
(Length) Continued from Table 3 (Tensile shear adhesive strength measurement results) When bonding translucent polybutylene terephthalate that slightly transmits visible light, which is a low level of light, by irradiation with light, conventional photopolymerization It can be seen that the photocurable adhesive of the present invention exhibits excellent photocurability and adhesive strength, whereas the photocurable adhesive containing a catalyst does not exhibit any adhesive strength. According to the results shown in the above Examples and Comparative Examples, since it contains a white pigment, it hardly transmits ultraviolet rays, which are light rays with high energy density, and (c) Effect of the invention on energy density. Photocurable adhesive according to the present invention. The agent has excellent curing properties when irradiated with ultraviolet rays as well as visible rays, which are harmless to the human body, so it is not only suitable for adhesion of transparent materials, but also curable when irradiated with ultraviolet rays, which have high energy density. Suitable for bonding semi-transparent materials that transmit only visible light, which is light with low energy density, such as ceramic materials such as alumina or silica, or plastic materials containing pigments or ceramic fillers. It also exhibits excellent sensitivity and adhesive strength.

Claims (1)

[Claims] 1. A photocurable adhesive comprising the following components A, B, and C. A: Radically polymerizable vinyl compound B: α-diketone C: Sensitizer represented by the following formula [I] ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [ I ] (However, group Q^1 and group Q^2 are mutually the same or different dialkylamino groups bonded to the carbonyl group independently in the o, m or p position.)