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.