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Photo Curable Resin Composition For Sealing Material And Sealing Method

Abstract: The present invention discloses a a photo-curable resin composition for sealing material comprising: (A) a compound having at least one oxetane ring, in a proportion of 3 to 86% by weight, (B) a photoinitiator for cationic polymerization, in a proportion of 0.1 - 10% by weight, (C) a silane coupling agent, in a proportion of 0.1 - 30% by weight, (D) a microparticulate inorganic filler, in a proportion of 0 - 70% by weight and (E) a compound having epoxy group, in a proportion of 0 - 99.7% by weight wherein the composition has a viscosity in the range from 0.01 to 300 Pa.s at 25°C.

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Patent Information

Application #
Filing Date
13 March 2001
Publication Number
Publication Type
INA
Invention Field
Status
Email
Parent Application
Patent Number
Legal Status
Grant Date
2006-07-14
Renewal Date

Applicants

MITSUI CHEMICALS INC.
2-5, KASUMIGASEKI 3-CHOME, CHIYODA-KU, TOKYO

Inventors

1. TAKAMATSU YASUSHI
2882-4-32, IIJIMA-CHO, SAKAE-KU, YOKOHAMA-SHI, KANAGAWA 244-0842
2. NAGATA KEI
5-11-203, TSUJIDOMOTOMACHI 5-CHOME, FUJISAWA-SHI, KANAGAWA 251-0043
3. OTA MASAHIRO
1-24, KAMINOMIYA 2-CHOME, TSURUMI-KU, YOKOHAMA-SHI, KANAGAWA 230-0075
4. MIZUTA YASUSHI
2882-3-27, IIJIMA-CHO, SAKAE-KU, YOKOHAMA-SHI, KANAGAWA 244-0842
5. KIKUTA YOSHIO
33-14, HIGASHIYAMADA, 3-CHOME, TSUZUKI-KU, YOKOHAMA-SHI, KANAGAWA 224-0023

Claims

1. A photo-ourable resin composition for sealing material comprising : (A) a compound having at least one oxetane ring, such as herein described, in a proportion of 3 to 86% by weight, (B) a photoinitiator, such as herein described, for cationic polymerization, in a proportion of 0.1 - 10% by weight, (C a silane coupling agent, such as herein described, in a proportion of 0.1 -30% by weight, (D) a microparticulate inorganic filler, such as herein described, in a proportion of 0 - 70% by weight and (E) a compound having epoxy group, such as herein described, in a proportion of 0 - 99.7% by weight wherein the composition has a viscosity in the range from 0.01 to 300 I''a.s at 25°C.

2. The photo-cirable resin composition for sealing material as claimed in claim 1, wherein the <;ured resin obtained by curing the photo-curable resin composition exhibits, under the condition of a temperature of 80°C and a relative humidity of 95%, a moist ire permeability of 250 g/(m2-24hr.) or less and an adhesive strength onto glass plate of 4.9 Mpa (50 kgf/cm2) or more.

3. A sealing material such as herein described, using the photo-curable resin composition as claimed in claim 1 or 2. with or without additional constituent(s) known per se

4. A method for scaling a display cell of liquid crystal display or electroluminescence display, comprising applying a sealing material to the cell and subjecting the material to curing, wherein said sealing material comprises (A) a compourd having at least one oxetane ring, in a proportion of 3 to 86% by weight, (B) a photoinitiator for cationic polymerization, in a proportion of 0.1 - 10% by weight, C) a silane coupling agent, in aproportion of 0.1 - 30% by weight, D) a microparticulate inorganic filler, in a proportion of 0-70% by weight and E) a compound having epoxy group, in a proportion of 0-99.7% by weight wherein the composition has a viscosity in the ran^e from 0.01 to 300 Pa.s at 25°C.

5. A display based on liquid crystal or electro luminescence comprising a display cell sealed by a sealing material wherein said sealing material comprises the photocurable resin composition as claimed in claim 1 or 2. The present invention discloses a a photo-curable resin composition for sealing material comprising: (A) a compound having at least one oxetane ring, in a proportion of 3 to 86% by weight. (B) a photoinitiator for cationic polymerization, in a proportion of 0.1 - 10% by weight. (C) a silane coupling agent in a proportion of 0.1 — 30% by weight, (D) a microparticulate inorganic filler, in a proportion of 0 - 70% by weight and (E) a compound having epoxy group, in a proportion of 0 - 99.1% by weight wherein the composition has a viscosity in the range from 0.01 to 300 Pa.s at 25°C.

Specification

FIELD OF THE INVENTION The present invention relates to a photo-curable resin composition for sealing material. BACKGROUND OF THE INVENTION In recent years, flat panel displays using various display elements have been developed and brought into industrial production in the electronic and electric industries. Many of these displays are made of cells of glass or plastic flat panels enclosing the display elements with sealing. Representatives of such displays are liquid crystal (LC) displays and electroluminescence (EL) displays. In general, LC display cell has the structure in which a layer of liquid crystal is placed between two substrate glass boards and is sealed along the circumference with a sealing material. Heretofore, thermosetting epoxy resins have been used for the sealing material. There was, however, a problem that a high productivity cannot be expected using such a sealing material of thermosetting epoxy resin, since it is necessary to heat the resin at a temperature as high as 150 - 180 °C for about two hours in order to attain sufficient curing of the epoxy resin. On the other hand, EL displays are superior in the high brightness, high efficiency and high responding speed and have attracted notice as flat panel display of next generation. As the display element, inorganic and organic EL display elements have been proposed and inorganic EL display elements are now in practical use for, for example, back illumination of a wrist watch and so on. Organic EL display elements are superior in the high brightness, high efficiency, high responding speed and polychroism, as compared with inorganic EL display elements, but have lower heat resistance with a heat stability temperature of some 60 - 80 °C. In sealing an organic EL display cell, there was, thus, a problem that satisfactory heat curing of the sealing is not attainable with thermosetting epoxy resin. For obviating these problems, it has been examined to use a photo-curable sealing material capable of being cured promptly at lower temperatures. As photo-curable sealing material, there are, in a rough grouping, two types, namely, a photo-radical polymerization type (photo-radical type) and a photo- cationic polymerization type (photo-cationic type). A photo-radical type sealing material, for which an acrylic resin has predominantly been used, has an advantage of capability of employing a wide variety of monomers and oligomers of acrylates, nevertheless it exhibits an insufficient resistance to moisture permeation and is further requested to lower its rate of volumetric contraction and to improve its adhesive strength. A photo-cationic type sealing material, for which an epoxy resin has predominantly been used, has a relatively better adhesive strength, nevertheless it is requested to be further improved in its photo- sensibility, prompt curability and moisture permeation resistance. The object of the present invention is to provide a photo-curable resin composition for sealing material for, in particular, display cells, which is curable at lower temperatures and which is superior in the photosensibility, in the prompt curing property, in the adhesive property, in the ability of forming a cured product exhibiting a high adhesive strength and in the resistance to moisture permeation, permits better productivity of the sealed product, such as display panels etc., and can be used favorably, above all, for flat panels of displays based on liquid crystal and on electroluminescence, and to provide a sealing material as well as to provide a sealing method using such a sealing material. DISCLOSURE OF THE INVENTION The inventors discovered from sound researches that the problems inherent in the conventional photo- curable resin composition for sealing material mentioned above can be obviated by using, for a photo- curable resin composition as the starting mixture of the sealing resin, a compound having oxetane ring, a photoinitiator for cationic polymerization and a silane coupling agent and that a photo-curable resin composition for sealing material, which is superior in the photosensibility, prompt curability, adhesive strength, resistance to moisture permeation and heat resistance, can be obtained by controlling the viscosity of the composition suitably, whereby the present invention has been completed. Accordingly, the present invention provides a photo- curable resin composition for sealing material comprising: (A) a compound having at least one oxetane ring, in a proportion of 3 to 86% by weight, (B) a photoinitiator for cationic polymerization, in a proportion of 0.1 - 10% by weight, (C) a silane Coupling agent, in a proportion of 0.1 - 30% by weight, (D) a micropan;iculate inorganic filler, in a proportion of 0 - 7 0% by weight and (E) a compound having epoxy group, in a proportion of 0 - 99.7% by weight wherein the composition has a viscosity in the range from 0.01 to 300 Pa.s at 25°C. Thus, the present invention resides in the following photo-curable resin composition, sealing material and method for sealing such a sealing material: (1) A photo-curable resin composition for sealing material, comprising (A) a compound having oxetane ring, (B) a photoinitiator for cationic polymerization and (C) a silane coupling agent, wherein the composition has a viscosity in the range from 0.01 to 300 Pa-s at 25 °C. (2) The photo-curable resin composition for sealing material as defined in the above (1), which comprises further (D) an inorganic filler of microparticles. (3) The photo-curable resin composition for sealing material as defined in the above (1) or (2), which comprises further (E) a compound having epoxy group. (4) The photo-curable resin composition for sealing material as defined in any one of the above (1) to (3), wherein it comprises (A) the compound having oxetane ring, in a proportion of 0.1 - 99.8 % by weight, (B) the photoinitiator for cationic polymerization, in a proportion of 0.1 - 10 % by weight (C) the silane coupling agent, in a proportion of 0.1 - 30 % by weight, (D) the microparticulate inorganic filler, in a proportion of 0 - 70 % by weight and (E) the compound having epoxy group, in a proportion of 0 - 99.7 % by weight. (5) The photo-curable resin composition for sealing material as defined in any one of the above (1) to (4), wherein the cured resin obtained by curing the photo- curable resin composition exhibits, under the condition of a temperature of 80 °C and a relative humidity of 95 %, a moisture permeability of 250 g/(m2.24 hr) or less and an adhesive strength onto glass plate of 4.9 MPa (50 kgf/cm2) or more. (6) A sealing material comprising the photo-curable resin composition as defined in any one of the above (1) to (5). (7) A sealing material for flat panel display comprising the photo-curable resin composition as defined in any one of the above (1) to (5). (8) A sealing material for liquid crystal displc?y or electroluminescence display, comprising the photo- curable resin composition as defined in any one of the above (1) to (5). (9) A method for sealing an article to be sealed, comprising applying the sealing material as defined in the above (6) to the article and subjecting the material to curing. (10) A method for sealing a display cell of liquid crystal display or electroluminescence display, comprising applying the sealing material as defined in the above (8) to the cell and subjecting the material to curing. (11) Sealed articles comprising cured layer of the sealing material as defined in the above (6), which seals the article. (12) A display based on liquid crystal or electro- luminescence, comprising a display cell sealed by the sealing material as defined in the above (8). Below, the present invention will be described in more detai1. (( The compound (A) having oxetane ring) For the compound (A) having oxetane ring to be incorporated in the composition according to the present invention, every compound having at least one oxetane ring represented by the formula (1) may be employed. There may be recited, for example, compounds having 1 to 15, preferably 1 to 10, especially preferably 1 to 4 oxetane rings. ( Compounds having one oxetane ring ) Every compound having one oxetane ring may be used for this, wherein preference is given, for example, to those represented by the formula (2) in which Z, R1 and R2 have the meanings as given below: Z stands for oxygen atom or sulfur atom. R1 denotes hydrogen atom; fluorine atom; an alkyl group having 1-6 carbon atoms, such as methyl, ethyl, propyl, butyl, pentyl or hexyl; a fluoroalkyl group having 1-6 carbon atoms, such as trifluoromethyl, perfluoromethyl, perfluoroethyl or perfluoropropyl; an aryl group having 6-18 carbon atcms, such as phenyl or naphthyl; a furyl group; or a thienyl group. R2 denotes hydrogen atom; an alkyl group having 1-6 carbon atcms, such as methyl, ethyl, propyl, butyl, pentyl or hexyl; an alkenyl group having 2-6 carbon atoms, such as 1-propenyl,. 2-propenyl, 2- methyl-1-propenyl, 2-methyl-2-propenyl, 1-butenyl, 2-butenyl or 3-butenyl; a substituted or non- substituted aralkyl group having 7-18 carbon atoms, such as benzyl, fluorobenzyl, methoxybenzyl, phenethyl, styryl, cinnamyl or ethoxybenzyl; an other aromatic ring-containing group, for example, an aryloxyalkyl, such as phenoxymethyl or phenoxyethyl; an alkylcarbonyl group having 2-6 carbon ai-.oms, such as ethylcarbonyl, propylcarbonyl or butyl c:arbonyl; an alkoxycarbonyl group having 2 6 carbon atoms, such as ethoxycarbonyl, propoxycarbonyl or butoxycarbonyl; and N-alkyl- carbamoyl group having 2-6 carbon atoms, such as ethylcarbamoyl, propylcarbamoyl, butylcarbamoyl and pentylcarbamoyl. It is permissible that the compound having one oxetane ring ias other substituent group(s) than those given above, in so far as the purpose of the invention is not obstructed thereby. More csncrete examples of the compound having one oxetane ring include 3-ethyl-3-hydroxymethyloxetane, 3- (meth)allylox"/methyl-3-ethyloxetane, (3-ethyl-3-oxetan- yl me thoxy) me thy;, benzene, 4-f luoro- {1- (3-ethyl-3-oxetanyl- methoxy)methyl}benzene, 4-methoxy-{l-(3-ethyl-3-oxetanyl- methoxy)methyl}fcenzene, {l-(3-ethyl-3-oxetanylmethoxy)eth- yl }phenyl ether, isobutoxymethyl(3-ethyl-3-oxetanylmeth- yl) ether, i sobornyloxyethyl ( 3-ethyl-3--oxetanylmethyl) ether, isobornyJ(3-ethyl-3-oxetanylmethyl) ether, 2-eth- ylhexyl(3-ethyl-3-oxetanylmethyl) ether, ethyl diethylene glycol(3-ethyl-3-oxetanylmethyl) ether, dicyclopentadi- ene(3-ethyl-3-oxetanylmethyl) ether, dicyclopentenyloxy- ethyl(3-ethyl-3-oxetanylmethyl) ether, dicyclopentenyl- ethyl(3-ethyl-3-oxetanylmethyl) ether, tetrahydrofurfur- yl(3-ethyl-3-oxetanylmethyl) ether, tetrabromophenyl(3- ethyl-3-oxetanylm The silane coupling agent to be used according to the present invention is a modifying agent known per se for improving the adhesive strength onto polymeric substrates or onto glass substrates, but can also improve the adhesive strength of such a resin onto various inorganic and organic substrates. For the silane coupling agent (C), silane compounds having a reactive group, such as epoxy, carboxy, methacryloyl or isocyanato, are employed. Concrete examples of the silane coupling agent include trimethoxysilyl benzoate, y -methacryloxypropyl- trimethoxysilane, vinyltriacetoxysilane, vinyltrimeth- oxysilane, y -isocyanatopropyltriethoxysilane, y -gly- cidoxypropy] trimethoxysilane and /3 - (3, 4-epoxycyclo- hexyl )ethyltrimethoxysilane. These compounds of the component (C) may be used either alone or in a combination of two or more of them. The component (C) improves adhesive strength. <( The microparticulate inorganic filler (D) ) The photo-curable resin composition according to the present invention may favorably contain the microparticulate inorganic filler (D). The micro- particulate inorganic filler has an average particle size of the: primary particles in the range from 0.005 to 10 µm. Concretely, the microparticulate inorganic filler consists of silica, talc, alumina, mica or calcium carbonate. For the microparticualte inorganic filler, those which have or have not been subjected to a surface treatment may be used. As the microparticul- ate filler which has been subjected to a surface treatment, for example, those methoxylated, trimethyl- silylated and octylsilylated ones and those having been subjected 'to a surface treatment with silicone oil may be. employed. These fillers (D) may be employed either alone or in a combination of two or more of them. The microparticulate inorganic filler (D) is effective for providing the cured resin with a resistance to moisture permeation, an adhesive strength and a thixotropy. ( The compound having epoxy group (E) > The photo-curable resin composition according to the present invention may favorably contain the compound having epoxy group (E). As the compound having epoxy group (E), those which are given below may be exemplified. As the compound having one epoxy group, there may be mentioned, for example, phenyl glycidyl ether and butyl glycidyl ether. As the compound having two or more epoxy croups, there may be mentioned, for example, hexanediol diglycidyl ether, tetraethyleneglycol diglycidyl ether, neopentylglycol diglycidyl ether, trimethylolpropane triglycidyl ether, bisphenol A diglycidyl ether, bisphenol F diglycidyl ether and novolak-type epoxy compounds. There; may be exemplified also alicyclic compounds having epoxy group in the ring, such as those represented by the formulae (25) and (26). These compounds for the component (E) may be employed either alone or in a combination of two or more of them. Incorporation of the component (E) is effective for improving the adhesive property and the heat resistarce of the sealing material according to the present invention. The photo-curable resin composition for sealing material according to the present invention contains the above components (A) to (C) as the inevitable constituents and the above components (D) and (E) as optional constituents. The compounding proportion of these components may usually be such that the composition comprises the component (A) in a proportion of 0.1 to 99.8 % by weight, preferably 1 to 93.4 % by weight, more preferably 3 to 86 % by weight, the component (B) in a proportion of 0.1 to 10 % by weight, preferably 0.3 to 8 % by weight, more preferably 0.5 to 6 % by weigh:, the component (C) in a proportion of 0.1 to 30 % by weight, preferably 0.3 to 20 % by weight, more preferably 0.5 to 10 % by weight, the component (D) in a proportion of 0 to 70 % by weight, preferably 5 to 60 % by weight, more preferably 10 to 50 % by weight, and the component (E) in a proportion of 0 to 99.7 % by weight, preferably 1 to 93.4 % by weight, more preferably 3 to 86 % by weight. { Other components) 2 1 The resin composition according to the present invention may contain, within the range not obstructing the purpose of the invention, other compound(s) subject to cationic polymerization, other resinous component, other filler, modifying agent(s), stabilizer and the 1ike. (Other compound(s) subject to cationic polymerization) For other compound(s) subject to cationic polymerization, there may be employed, for example, oxolane compounds, cyclic acetals, cyclic lactones, thiirane compounds, thiethane compounds, spiro-ortho- esters, vinyl ethers, ethylenically unsaturated compounds, cyclic ethers, cyclic thioethers and vinyl compounds. They may be employed either alone or in a combination of two or more of them. ( Other resinous component) For other resinous component, there may be mentioned, for example, polyamides, polyamidoimides, polyurethanes, polybutadiene, polychloroprene, polyethers, polyesters, styrene/butadiene/styrene block copolymer, petroleum resin, xylol resin, ketone resin, cellulose resin, fluorine-containing oligomers, oligomers based on silicone, oligomers based on polysulfide, ctcrylic rubber and silicon rubber. They can be employed either alone or in a combination of two or more of then. ( Other filler) For such other filler, there may be mentioned, for example, glass beads, particulate polymers based on styrene, particulate polymers based on divinylbenzene, particulate polymers based on methacrylate, particulate polymers based on ethylene and particulate polymers based on propylene. They may be employed either alone or in a combination of two or more of them. ( Modifying agent ) For the modifying agent, there may be mentioned, for example, assistant polymerization initiator, antioxidant, levelling agent, wettability improving agent, surfactant, plasticizer and UV absorber. They may be employed either alone or in a combination of two or more of them. Preparation of the resin composition The photo-curable resin composition for sealing material according to the present invention is prepared by mixing the constituent components uniformly in such a manner thc:t the blend has a viscosity in the range from 0.01 to 300 Pa-s at 25 °C. The resin composition having a visrosity in the range of 0.01 - 300 Pa- s at 25 °C is favorable for its easy and efficient workability en application onto the substrate such as flat panel of display and for its better blend stability. It is more preferable that the resin composition has a viscosity in the range of 0.1 - 100 Pa- s at 25 °C. The v:.scosity of the resin composition can be adjusted by an adequate choice of the constituting components and mixing proportion thereof and by addition of other component(s), if necessary. The components (A) and (E) of lower molecular weights are in a liquid state at normal temperature and, therefore, the viscosity Df the composition can easily be adjusted within the above-mentioned range by dissolving or dispersing other solid components in these liquid components. If the viscosity is higher, the blending work can be realized efficiently by a conventional practice, for example, using a three roll kneader. { The sealing material) The sealing material according to the present invention camprises the photo-curable resin composition described aoove. Such sealing material may be either constituted of only the above-mentioned components of the resin composition or constituted of these components with addition of other constituent ingredients. Such other constituent ingredients may include, for example, particulate material to be served as a spacer. (( Method for sealing) The method for sealing an article to be sealed according to the present invention comprises sealing thes article with the sealing material described above and subjecting the material to curing by irradiation of light. As the article to be sealed by the method with the sealing material according to the present invention, display cells on flat panel of LC display and of EL display may be mentioned as representative ones, though semiconductor devices, such as those in which semiconductor elements,, such as CCD etc., are encased in a casing with closure member, and those in which gas tight sealing is maintained for evading permeation o:: moisture, may also be sealed by the method according to the present: invention. As for the practical way of applying the sealing material according to the present invention on an article to be sealed, such as display substrate board or so on, no special restriction is placed thereon so long as a uniform application is permitted. It is enough to cipply the sealing material onto the article to be sealed by way of a known practice, such as screen printing or use of a dispenser. In sealing a display cell, the sealing material according to the present invention is interposed between two substrate boards so as to enclose the display element to build up the display cell therebetween, whereon the resulting assembly is subjected to irradiation of a light to cause curing of the sealing material at a lower temperature. For the light source, any one permitting to cause curing of the sealing material within a contemplated working time may be used. Usually, a light source capable of radiating a light of a wave length within the range of ultraviolet to visible light is employed. In the practice, a low pressure mercury lamp, a high pressure mercury lamp, xenon lamp or a metal halide lamp is used. The dosage of the light irradiation mciy usually be selected adequately within the range in which no residue of uncured resin composition remains or no deterioration in the adhesion occurs in cas;e the irradiation dose is low, while ordinary dosagt; is in the range of 500 - 3,000 mJ/cmz . While there is no special upper limit is placed on the irradiation dosage, a superfluous dosage may not be favorable in view of the lowering of the productivity and uneconomical energy consumption. By subjecting the assembly, obtained after application of the above-mentioned sealing material onto the article to be sealed, to irradiation of light, the photo-curable resin composition is cured to build up a sealei article. In this manner, for example, a display panel is obtained in case the sealed article is a diaplay cell or a semiconductor device, such as CCD, sealed in a similar way is obtained in case the sealed article is a semicontuctor element. Material properties of the cured resin The material properties of the cured resin of the photo-curable composition according to the present invention are determined by the methods given below. O Moisture permeation rate A film sample (with a thickness of 100u m) of the photo-cured resin composition is tested for its moisture permeation rate according to JIS Z 0208. ¦Q Adhesive strength A layer (with a thickness of 100 u m) of the resin composition according to the present invention is placed between two glass plates and the resulting assembly is subjected to irradiation of a light, in order to cause the resin composition to be cured into an adhered sample. The adhesive strength is determined by observing the force to peel off the glass plate from each other at a rate of drawing of the glass plates of 2 mm/min. The cured mass obtained by curing the photo- curable re;;in composition according to the present invention nas a moisture permeation rate under the condition cf 80 °C and 95 % relative humidity of 250 g/(m2-24 hrI or less and an adhesive strength of 4.9 MPa (50 kgf/cm2 ' or more. A photo-curable resin composition having the properties as given above shows a better balance between the resistance to moisture permeation and the adhesive property and, thus, is adapted for a sealing material. While it is difficult in general to satisfy both these conditions simultaneously, this can be attained by the photo-curable resin composition for sealing material according to the present invention. As described above, it is made possible by using an oxetane ring-containing compound, a photoinitiator for cationic polymerization and a silane coupling agent and by controlling the viscosity in accordance with the present invention, to obtain a photo-curable resin composition ::or sealing material for, in particular, display cell, which is curable at lower temperatures and which is superior in the photosensibi li ty, in the prompt curing property, in the adhesive property, in the ability Df forming a cured product exhibiting a high adhesive: strength and in the; resistance to moisture permeation, permits better productivity of the sealed product, such as display etc., and can be used favorably for flat panels of displays based on LC and EL. THE BEST MODE FOR EMBODYING THE INVENTION Below, the present invention will be described in detail by way of Examples, though the present invention should not be restricted by these Examples. Testing methods For the photo-curable resin compositions and the cures products obtained, the following assessments were carried out. 8 Viscosity The viscosities of the resin compositions before curing were determined using a rotary cone/disc viscometer at 25 °C. §' Curing performance The curing performance of the resin composition is assessed by coating a glass plate with a layer of the resin ccmposition in a thickness of 100 p. m and the coated layer is subjected to irradiation of light, whereupon the state of curing of the coated layer is assessed by finger touch with the assessment rating criterion given below. C) : sufficiently cured L\ : partial uncured residue > : not cured § Adhesive strength Adhesive strength was determined by the method given previously. § Rate of permeation of moisture Moist are permeation rate was determined by the method given previously. Starting materials § The compound (A) having oxetane ring Oxetane a-1: 1,4-bis{(3-ethyl-3-oxetanylmethoxy)- methyl}benzene Oxetane a-2: 3-ethyl-3-hydroxyinethyloxetane § Photoinitiator (B) for cationic polymerization Photoinitiator b-1: the compound represented by the formula (27) Photoilitiator b-2: the compound represented by the formula (28) 3 The silane coupling agent (C) Silane coupling agent c-1: r -glycidoxypropyltrimethoxysi1ane ?i Micropart iculate inorganic filler (D) Microperticulate silica d-1: a microparticulate talc having an average particle size of the primary particles of 1 p. m without being subjected to surface treatment Microparticulate silica d-2: a microparticulate silica having an average particle size of the primary particles of 12 nm without being subjected to surface treatment § Compound having epoxy group (E) Epo::y compound e-1: Bisphenol F diglycidyl ether Epoxy compound e-2: the compound represented by the formula (29) Epoxy compound e-3: the compound represented by the formula (30) Epoxy compound e-4: the compound represented by the formula (25) EXAMPLE 1 Preparation of the photo-curable resin composition By compounding, in accordance with the blending recipi given in Table 1, 94 parts by weight of the oxetane a-1, namely, 1,4-bis{(3-ethyl-3-oxetanylmethoxy)- methyl}benzene, as the compound (A), 3 parts by weight of the photoinitiator b-1 of the formula (27), as the photoinitiator (B) for cationic polymerization, and 3 parts by weight of the silane coupling agent c-1, namely, r -glycidoxypropyltrimethoxysilane, as the silane coupling agent (C), and agitating the mixture for 1 hour, a transparent liquid composition was obtained. Photo-curing A layer (with a thickness of 100 u m) of the resin composition obtained as above was interposed in between two glass plates (JIS R-3202) and the resulting assembly was subjected to irradiation of a light from a metal halide lamp at 3,000 mJ/cm2 to cause the resin composition to be cured. The curing performance and the material properties of the cured product were assessed, the results of which are recited in Table 2. EXAMPLES 2-8 In the same manner as in EXAMPLE 1 except that the components given in Table 1 were employed, resin compositions were prepared and the assessments as in EXAMPLE 1 were carried out, the results of which are recited in Table 2. COMPARATIVE EXAMPLES 1-8 In the same manner as in EXAMPLE 1 except that the components given in Table 3 were employed, resin compositions were prepared and the assessments as in EXAMPLE 1 w = re carried out, the results of which are recited in Table 4. INDUSTRIAL APPLICABILITY The sealing material comprising the photo- curable resin composition for sealing material according to the present invention can be used favorably for sealing an article to be sealed, such as flat panels of display cells for displays based on liquid crystal or on electroluminescence and semiconductor devises of, for example, CCD and so on. WE CLAIM : 1. A photo-ourable resin composition for sealing material comprising : (A) a compound having at least one oxetane ring, such as herein described, in a proportion of 3 to 86% by weight, (B) a photoinitiator, such as herein described, for cationic polymerization, in a proportion of 0.1 - 10% by weight, (C a silane coupling agent, such as herein described, in a proportion of 0.1 -30% by weight, (D) a microparticulate inorganic filler, such as herein described, in a proportion of 0 - 70% by weight and (E) a compound having epoxy group, such as herein described, in a proportion of 0 - 99.7% by weight wherein the composition has a viscosity in the range from 0.01 to 300 I''a.s at 25°C. 2. The photo-cirable resin composition for sealing material as claimed in claim 1, wherein the <;ured resin obtained by curing the photo-curable resin composition exhibits, under the condition of a temperature of 80°C and a relative humidity of 95%, a moist ire permeability of 250 g/(m2-24hr.) or less and an adhesive strength onto glass plate of 4.9 Mpa (50 kgf/cm2) or more. 3. A sealing material such as herein described, using the photo-curable resin composition as claimed in claim 1 or 2. with or without additional constituent(s) known per se 4. A method for scaling a display cell of liquid crystal display or electroluminescence display, comprising applying a sealing material to the cell and subjecting the material to curing, wherein said sealing material comprises (A) a compourd having at least one oxetane ring, in a proportion of 3 to 86% by weight, (B) a photoinitiator for cationic polymerization, in a proportion of 0.1 - 10% by weight, C) a silane coupling agent, in aproportion of 0.1 - 30% by weight, D) a microparticulate inorganic filler, in a proportion of 0-70% by weight and E) a compound having epoxy group, in a proportion of 0-99.7% by weight wherein the composition has a viscosity in the ran^e from 0.01 to 300 Pa.s at 25°C. 5. A display based on liquid crystal or electro luminescence comprising a display cell sealed by a sealing material wherein said sealing material comprises the photocurable resin composition as claimed in claim 1 or 2. The present invention discloses a a photo-curable resin composition for sealing material comprising: (A) a compound having at least one oxetane ring, in a proportion of 3 to 86% by weight. (B) a photoinitiator for cationic polymerization, in a proportion of 0.1 - 10% by weight. (C) a silane coupling agent in a proportion of 0.1 — 30% by weight, (D) a microparticulate inorganic filler, in a proportion of 0 - 70% by weight and (E) a compound having epoxy group, in a proportion of 0 - 99.1% by weight wherein the composition has a viscosity in the range from 0.01 to 300 Pa.s at 25°C.

Documents

Application Documents

# Name Date
1 in-pct-2001-285-kol-granted-translated copy of priority document.pdf 2011-10-08
2 in-pct-2001-285-kol-granted-specification.pdf 2011-10-08
3 in-pct-2001-285-kol-granted-reply to examination report.pdf 2011-10-08
4 in-pct-2001-285-kol-granted-priority document.pdf 2011-10-08
5 in-pct-2001-285-kol-granted-letter patent.pdf 2011-10-08
6 in-pct-2001-285-kol-granted-gpa.pdf 2011-10-08
7 in-pct-2001-285-kol-granted-form 5.pdf 2011-10-08
8 in-pct-2001-285-kol-granted-form 3.pdf 2011-10-08
9 in-pct-2001-285-kol-granted-form 2.pdf 2011-10-08
10 in-pct-2001-285-kol-granted-form 18.pdf 2011-10-08
11 in-pct-2001-285-kol-granted-form 1.pdf 2011-10-08
12 in-pct-2001-285-kol-granted-examination report.pdf 2011-10-08
13 in-pct-2001-285-kol-granted-description (complete).pdf 2011-10-08
14 in-pct-2001-285-kol-granted-correspondence.pdf 2011-10-08
15 in-pct-2001-285-kol-granted-claims.pdf 2011-10-08
16 in-pct-2001-285-kol-granted-abstract.pdf 2011-10-08
17 in-pct-2001-00285-kol-priority document.pdf 2011-10-08
18 in-pct-2001-00285-kol-priority document others.pdf 2011-10-08
19 in-pct-2001-00285-kol-g.p.a.pdf 2011-10-08
20 in-pct-2001-00285-kol-form-5.pdf 2011-10-08
21 in-pct-2001-00285-kol-form-3.pdf 2011-10-08
22 in-pct-2001-00285-kol-form-2.pdf 2011-10-08
23 in-pct-2001-00285-kol-form-18.pdf 2011-10-08
24 in-pct-2001-00285-kol-form-1.pdf 2011-10-08
25 in-pct-2001-00285-kol-description(complete).pdf 2011-10-08
26 in-pct-2001-00285-kol-correspondence.pdf 2011-10-08
27 in-pct-2001-00285-kol-claims.pdf 2011-10-08
28 in-pct-2001-00285-kol-abstract.pdf 2011-10-08

ERegister / Renewals