JP3500195B2 - Optical sheet and method for producing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical sheet suitable for applications such as electrode substrates for liquid crystal display panels. The present invention also relates to a method for industrially producing the optical sheet.

[0002]

Conventionally, glass has been used as an electrode substrate for a liquid crystal display panel (that is, a substrate of a liquid crystal cell), but it is heavy, cannot be thinned, is easily damaged, and is mass-produced. Due to problems such as difficulty, plastic substrates have become popular recently.
The present applicant has also filed the following patent applications.

In Japanese Patent Laid-Open No. 63-71829, an air permeation-resistant resin layer is provided on at least one surface of an optically isotropic substrate sheet layer via an anchor coat layer, and a cross-linkable resin is further formed on the air permeation-resistant resin layer. An electrode substrate for a liquid crystal display panel having a configuration in which a cured product layer is provided is shown.

In Japanese Patent Laid-Open No. 64-50021, two laminated films comprising a gas-permeable resin layer / cured crosslinkable resin layer are provided with an adhesive layer with the gas-permeable resin layers facing each other. An electrode substrate for a liquid crystal display panel is shown, which is laminated and integrated through the electrode substrate.

In JP-A-64-50022, a solution or dispersion of a gas-permeable resin is cast on the surface of a heat-resistant synthetic resin film and then dried to form a gas-resistant synthetic resin film layer. Further, a solution or dispersion of the crosslinkable resin composition is cast thereon and then cured to form a cured crosslinkable resin layer, and then the heat-resistant synthetic resin film is changed to an air-permeable synthetic resin film layer and a crosslinkable resin. While peeling the laminate with the cured product layer, a solution or dispersion of the crosslinkable resin composition is cast on the surface of the laminate on the side of the air-permeable synthetic resin film layer, and then cured to cure the crosslinkable resin. It is shown that an electrode substrate for a liquid crystal display panel having a structure of a crosslinked resin cured product layer / an air permeation resistant resin layer / a crosslinked resin cured product layer is obtained by forming a material layer. Here, a typical example of the crosslinkable resin composition is a solvent solution of a phenoxy ether type crosslinkable polymer.

In Japanese Patent Laid-Open No. 4-159518, an air permeation resistant resin layer is provided on at least one side of an optically isotropic substrate sheet layer (1) by a casting method, and the air permeation resistant resin layer is further cast on the air permeation resistant resin layer. A liquid crystal having a constitution in which two or more unit laminate sheets provided with a cured crosslinkable resin layer by the method are attached via an adhesive layer so that the cured crosslinkable resin layers are both outermost layers. An electrode substrate for a display panel is shown.

[0007]

The liquid crystal display panel has made remarkable progress in the last few years, and is in the trend of increasing in size year by year. Glass substrates are still the mainstream as electrode substrates for liquid crystal display panels, but they are gradually being replaced by plastics substrates, and electronic notebooks, pen-input computers, and mobile phones, which have recently become popular, are becoming popular. In the case of portable equipment such as, plastics substrates are considered to be advantageous from the viewpoint of preventing damage and reducing weight.

When a plastics substrate is used, it is required to use a thick plastics substrate in response to the increase in size of the substrate. This is because the thin plastic substrate does not immediately return to its original shape when touched.
This is because there is a problem that a liquid crystal ring is generated at a place where it is touched by hand. The use of a thick plastic substrate also has an advantage that the manufacturing apparatus and manufacturing process of a conventional liquid crystal display panel using a glass substrate can be adopted as they are.

A transparent electrode such as ITO is formed on an electrode substrate for a liquid crystal display panel (that is, an electrode substrate of a liquid crystal cell), and the transparent electrode is used as a pattern electrode through resist formation and etching. The patterned transparent electrode is connected to the outer lead of the control IC after the liquid crystal cell is assembled or the liquid crystal display panel is assembled, and the connection between the pattern electrode and the outer lead at that time is as follows.
Recently, it is performed by thermocompression bonding with an anisotropic conductive sheet interposed therebetween. The thermocompression bonding in this case is
Typically, the temperature is 150 to 190 ° C., the applied pressure is about 0.5 MPa, and the joining time is about 10 seconds, and the temperature of the connection portion is about 130 to 150 ° C. Here, the anisotropic conductive sheet is a sheet in which conductive particles such as carbon powder, metal plating powder, metal powder, and solder balls are dispersed in a thermosetting or thermosetting resin. If the anisotropic conductive sheet is attached to the pattern electrode and the outer lead is aligned with the outer lead, thermocompression bonding is performed from the outer lead side with a heater block (bonding tool), so that the pattern electrode and the outer lead are separated by the dispersed conductive particles. You can connect all at once.
In this case, the conductive particles are in a drowsy state.

However, when the plastics substrate as described in each of the above-cited publications is used as the electrode substrate, the softening temperature of the layer is increased even if the surface layer of the substrate is made of a crosslinked resin cured material layer. It is not necessarily high, and since the softening temperature of the air-permeable resin layer on the inner side is also lower than that of the crosslinkable resin cured product layer, the conductive particles do not dash during the thermocompression bonding, and In some places, it deforms into a concave shape (that is, the conductive particles come to be embedded in the electrode substrate), and as a result, a damage defect such as a crack may occur in the pattern electrode.

The present invention has the following background.
When an optical sheet made of plastics is used as an electrode substrate, the pattern electrodes and the outer leads of the control IC are collectively connected by thermocompression bonding with an anisotropic conductive sheet interposed therebetween. It is an object of the present invention to provide an optical sheet that is excellent in thermal dimensional stability without causing any troubles when performed by the method described above, and to provide an industrially advantageous method for producing such an optical sheet. It is what

[0012]

The optical sheet of the present invention comprises an optical sheet made of plastics as an electrode substrate.
The pattern electrode and the control IC
A collective connection between the lead and the anisotropic conductive sheet
Light for performing thermocompression bonding with the interposition of
A academic sheet, which is a non-solvent type curable resin cured product on at least one surface of a single-layer or multi-layer core material layer (V).
Via adhesive layer comprising a layer of (A), JIS K5400
A three-dimensional hard-softened three-dimensional crosslinked layer (H) made of a non-imide resin having a surface hardness of H or more under a load of 100 g and a heat distortion temperature of 130 ° C. or more determined by the heat sag method is laminated. .

[0013] The method for producing an optical sheet of the present invention, plastic
Optical sheet made of sticky is used as electrode substrate
The outer leads of the pattern electrode and the IC for control
And the anisotropic conductive sheet between them.
An optical sheet for performing the thermocompression bonding method in the closed state.
A method for producing a sheet, comprising: a support film (S),
The hardness according to JIS K5400 (load 100 g) is H or more, and the heat distortion temperature obtained by the heat sag method is 130.
A step of preparing a first laminated film (L1) having a layer structure of (S) / (H) by forming a hard and high softening point three-dimensional crosslinked layer (H) made of a non-imide resin at a temperature of ℃ or higher. A, step B of preparing a single-layer or multiple-layer core material layer (V), the hard and softening point three-dimensional crosslinked body layer (H) side of the first laminated film (L1) and the core material layer (V) The non-solvent type curable resin liquid (a) was supplied between the first and second laminated films (L1) and the core material layer (V), and the curable resin liquid (a) layer was sandwiched between them. Cured in the state to form an adhesive layer (A) consisting of a curable resin cured product layer,
Second laminated film (L) having a layer structure of (S) / (H) / (A) / (V)
It is characterized in that step C for obtaining 2) is carried out.

After step C, between the core material layer (V) side of the second laminated film (L2) and the hard and softening point three-dimensional crosslinked body layer (H) side of the first laminated film (L1). The non-solvent type curable resin liquid (a) is supplied and cured with the layer of curable resin liquid (a) sandwiched between the second laminated film (L2) and the first laminated film (L1). To form an adhesive layer (A) composed of a curable resin cured product layer, (S) / (H) / (A) / (V) / (A) / (H) /
It is desirable to carry out step D for obtaining the third laminated film (L3) having the layer constitution of (S).

The present invention will be described in detail below.

In step A, JI is formed on the support film (S).
By forming a hard and high softening point three-dimensional crosslinked body layer (H) made of a non-imide resin having a hardness of SK5400 (load of 100 g) of H or higher and a heat deformation temperature of 130 ° C. or higher determined by the heat sag method, It is a step of preparing a first laminated film (L1) having a layer structure of (S) / (H).

The heat distortion temperature measured by the heat sag method has a width of 1
Using a test piece of 5 mm × length 30 mm × thickness 50 μm, and projecting the test piece by 15 mm from the end of the table, the horizontal axis is the set temperature (° C) and the vertical axis is the hanging height at that time. Plot the amount of change (mm), draw a curve, extend the tangent line at the inflection point of the curve to find the intersection with the level of 0 mm change, and define the temperature (℃) as the heat distortion temperature. It was done.

As the support film (S), films such as biaxially oriented polyester film and biaxially oriented polypropylene film are used. The polyester in the biaxially stretched polyester film is polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate or the like. Although the thickness of the support film (S) is arbitrary, it is often about 10 to 200 μm.

The surface roughness of the support film (S) directly affects the surface roughness of the finally obtained optical sheet. Therefore, when trying to obtain an optical sheet having a high surface smoothness, it is preferable to use a support film (S) whose inner surface is a smooth surface having a surface roughness of ± 0.1 μm or less. preferable.

The hard and high softening point three-dimensional crosslinked layer (H) made of a non-imide resin has a hardness of H or more (especially 2H or more) and a heat distortion temperature of 130 ° C or more (especially 150 ° C).
The hard and high softening point three-dimensional crosslinked body layer that provides the above layer) can be mentioned. Typical examples of this hard and high softening point three-dimensional crosslinked layer (H) are vinylbenzylimidazole resin, brominated phenoxy resin, phenoxy resin, epoxy acrylate resin, epoxy urethane resin, polyester acrylate resin, polyurethane acrylate resin and polyester urethane acrylate. It is a three-dimensional crosslinked layer of at least one resin selected from the group consisting of resins. The thickness of the hard and high softening point three-dimensional crosslinked body layer (H) is often 2 to 200 μm.

From the top of the three-dimensional hard-softening point three-dimensional crosslinked body layer (H), if necessary, SiO ₂ , SiOx (1 <x <
2), Al ₂ O ₃ , Fe ₂ O ₃ , MgCO ₃ , CeO ₂ , Z
nO, TiO ₂ , ZrO ₂ , ITO, BaTiO ₃ , L
It is also possible to provide a transparent ceramic layer such as iNbO ₃ , KTaO ₃ , PbO, calcium aluminate, glass, or a layer of a mixture thereof. The transparent ceramic layer is formed by a vacuum thin film forming method such as a vacuum vapor deposition method and a sputtering method, a sol-gel method using a metal alkoxide, a coating method using water glass as a raw material, and the like. The thickness of the transparent ceramics layer is usually set in the range of 200 Å to 1 μm, preferably 500 to 800 Å.

By forming the hard-softening point three-dimensional crosslinked body layer (H) on the support film (S), the first laminated film (L1) having a layer structure of (S) / (H) is obtained. .

Step B is a step of preparing a single-layer or multi-layer core material layer (V). This core layer (V) has at least 1
It is desirable to have a layer having gas barrier properties of the layer. Examples of the core layer (V) include vinyl alcohol-based resins (polyvinyl alcohol, polyvinyl alcohol cross-linked modified products, polyvinyl alcohol graft-modified products, ethylene-vinyl alcohol copolymers, etc.), acrylonitrile-based resins, vinylidene chloride-based resins, Examples include layers of air-permeable resins such as polyamide resins, natural polymers (cellulose polymers, starch polymers, plant mucilage polymers, protein polymers, etc.), which are water resistant. In many cases, a cross-linking agent is mixed to improve the film formation. Polycarbonate, polyarylate, polysulfone, polyether sulfone, at least one surface of the base material layer such as amorphous polyolefin, if necessary via an anchor coating layer, also those provided with a layer of air-permeable resin as described above, It can be preferably used as the core material layer (V). The thickness of the core layer (V) is often 20 to 500 μm,
It does not matter if it is thicker.

In step C, a non-solvent type curable resin liquid (between the hard and high softening point three-dimensional crosslinked body layer (H) side of the first laminated film (L1) and the core material layer (V) is used. a) is supplied, and a curable resin liquid is applied between the first laminated film (L1) and the core material layer (V).
By curing the layer (a) in a sandwiched state to form an adhesive layer (A) consisting of a curable resin cured product layer, (S) / (H) /
It is a step of obtaining a second laminated film (L2) having a layer structure of (A) / (V).

As the non-solvent type curable resin liquid (a), first, an active energy ray curable resin liquid composed of an ultraviolet curable resin liquid or an electron beam curable resin liquid is used. Examples of the former UV curable resin include a photopolymerizable prepolymer or / and a monomer, and optionally other monofunctional or polyfunctional monomers, various polymers, and photopolymerization initiators (acetophenones, benzophenones, Michler's ketone). , Benzyl, benzoin, benzoin ether, benzyl ketals, thioxanthones, etc.),
A resin composition containing a sensitizer (amines, diethylaminoethyl methacrylate, etc.) is used. Viscosity is 3
It is preferable that the viscosity is as high as 000 cps / 25 ° C or higher. Here, examples of the photopolymerizable prepolymer include polyester acrylate, polyester urethane acrylate, epoxy acrylate, and polyol acrylate, and examples of the photopolymerizable monomer include monofunctional acrylate, bifunctional acrylate, and trifunctional or higher functional acrylate. To be done. As the photopolymerizable prepolymer or monomer, a phosphazene resin may be used in addition to the above. Although the latter electron beam curable resin liquid having the same composition is used, it is not necessary to add a photopolymerization initiator or a sensitizer.

As the non-solvent type curable resin liquid (a), in addition to the above active energy ray curable resin liquid, a phenoxy ether type crosslinkable resin liquid, polyethylene glycol or polypropylene glycol and an aliphatic polyisocyanate compound are used. Thermosetting resin liquids including resin liquids composed of a mixture can also be used.

The thickness of the adhesive layer (A) consisting of the cured resin layer after curing is as thin as about 2 μm,
The thickness can be arbitrarily set up to 400 μm or more, and this is one of the features of the present invention.

A non-solvent type curable resin solution (a) is supplied between the hard and high softening point three-dimensional crosslinked body layer (H) side of the first laminated film (L1) and the core material layer (V). , First laminated film
In order to form an adhesive layer (A) consisting of a curable resin cured product layer by curing with a layer of curable resin liquid (a) sandwiched between (L1) and core layer (V) Specifically, the following method is adopted.

That is, the first laminated film (L1) and the core material layer
(V) is supplied to each of a pair of rolls arranged in parallel with a slight gap, and the non-solvent type curable resin liquid (a) is discharged toward the gap between the rolls and both rolls are The first film by rotating the
The non-solvent type curable resin liquid (a) is sandwiched between (L1) and the core layer (V), and UV or electron beam irradiation or heat curing is performed in such a sandwiched state. By doing so, the non-solvent type curable resin liquid (a) is cured to form an adhesive layer (A) composed of a curable resin cured product layer.

Step D is between the core material layer (V) side of the second laminated film (L2) and the hard and softening point three-dimensional crosslinked body layer (H) side of the first laminated film (L1). The non-solvent type curable resin liquid (a) is supplied and cured with the layer of curable resin liquid (a) sandwiched between the second laminated film (L2) and the first laminated film (L1). To form an adhesive layer (A) composed of a curable resin cured product layer, (S) / (H) / (A) / (V) / (A) / (H) /
It is a step of obtaining a third laminated film (L3) having a layer structure of (S). This step D can be performed in the same manner as step C described above.

If the support film (S) is peeled off from the second laminated film (L2) or the third laminated film (L3) at any stage after completion of the above-mentioned step C or step D,
It is possible to obtain a target sheet having a layer structure of (H) / (A) / (V) or (H) / (A) / (V) / (A) / (H).

The hard and high softening point three-dimensional crosslinked body layer (H) in step A, the adhesive layer in step C or step D
In order to achieve more complete curing of (A), reduction of retardation value and improvement of dimensional stability, Step C or Step D
It is also possible to perform heat treatment or curing at an appropriate stage later than that.

Further, in the present invention, step A or /
Further, the functional layer can be preliminarily provided on the inner surface of the support film (S) in the step D so as to be transferred. As such a functional layer, a transparent electrode (ITO
Etc.), scratch-resistant layers, antiglare layers, color filter layers and the like. If such a functional layer is provided on the inner surface side of the support film (S) in advance, the functional layer is transferred to the remaining layer when the support film (S) is peeled off, and the functional layer is attached. An optical sheet can be obtained all at once.

The optical sheet of the present invention is particularly useful as an electrode substrate for liquid crystal display panels (substrate for liquid crystal cells), and can be applied to not only small or medium-sized electrode substrates for large TN and STN liquid crystals. In addition, it can be used for various recording devices (optical cards, optical disks, etc.), display devices (polymer liquid crystal display substrates, etc.), and the like.

[0035]

The optical sheet of the present invention comprises a hard and high softening point three-dimensional crosslinked body layer (H) composed of a non-imide resin having a surface hardness of H or more and a heat distortion temperature of 130 ° C. or more, a single layer or a multilayer. Each of the core material layer (V) and the adhesive layer (A) consisting of a non-solvent type curable resin cured product layer is (H) / (A) / (V) or (H) / (A) /
It is formed in a layer structure of (V) / (A) / (H).

In this optical sheet, a hard and high softening point three-dimensional crosslinked body layer (H) is arranged as a surface side layer on one side or both sides of the core layer (V) through the adhesive layer (A). Top, core layer
Since a layer having a gas barrier property can be used as (V), high surface hardness, excellent heat resistance (non-softening property), thermal dimensional stability, due to the presence of the hard and high softening point three-dimensional crosslinked layer (H), Moisture resistance, chemical resistance, and transparent electrode adhesion are obtained, and the presence of the core layer (V) provides overall strength and excellent gas barrier properties.

And a hard and high softening point three-dimensional crosslinked body layer (H)
Exists as a surface side layer, so a transparent electrode such as ITO is formed on the substrate made of this optical sheet to form a pattern electrode, and the outer lead of the control IC is used after the liquid crystal cell is assembled or the liquid crystal display panel is assembled. upon collectively connected, the connection between the pattern electrodes and the outer leads, when performed by thermocompression bonding in a state where the anisotropic conductive sheet is interposed between them, the conductive particles at the time of thermocompression bonding squashed There is no danger that the electrode substrate will be deformed into a concave shape at the conductive particles (that is, there is no risk that the conductive particles will sink into the electrode substrate), and as a result, damage defects such as cracks will not occur on the pattern electrode. .

Further, in the present invention, the adhesive layer (A) made of a non-solvent type curable resin cured product is installed, and two rolls are provided for each of a pair of rolls arranged in parallel with a slight gap. Supply the film, discharge the non-solvent type curable resin liquid (a) toward the gap between the rolls, and rotate both rolls in the direction to bite each other.
Since (a) is sandwiched between two films, the thickness of the adhesive layer (A) made of a non-solvent type curable resin cured product can be arbitrarily set from extremely thin to extremely thick. it can. This method has extremely good industrial productivity, and the film thickness can be changed only by adjusting the gap between a pair of rolls arranged in parallel, so it is very easy and pressure can be applied. It has excellent thickness accuracy and flatness, can easily remove air, and solves the problem of dust adhesion. Further, even when orientation occurs in the curing process of the resin liquid (a), since it can be relaxed by heating before the resin liquid (a) is completely cured, the adhesive layer (A) having an extremely small retardation value Can be obtained.

Since it is possible to form a thick optical sheet (plastic substrate) and has high thermal dimensional stability, there is an advantage that the manufacturing apparatus and manufacturing process of a conventional liquid crystal display panel using a glass substrate can be directly adopted. .

As described above, the thickness of the adhesive layer (A) can be increased and the symmetry can be maintained, so that curling hardly occurs. Therefore, when this is used as an electrode substrate, not only small and medium-sized panels but also large-sized liquid crystal display panels using TN liquid crystal and STN liquid crystal can be dealt with. High thermal dimensional stability means that it is also suitable for color display of a panel using STN liquid crystal.

When a support film (S) having a small surface roughness is selected, it serves as a template, the surface smoothness of which is transferred to the outermost layer of the final optical sheet, and the surface roughness ± An optical sheet of 0.1 μm or less (optical sheet having smoothness equivalent to that of STN polished glass) can be easily obtained. Therefore, no special operation is required to smooth the surface of the electrode substrate as in the conventional case.

If a functional layer such as a transparent electrode is preliminarily provided on the inner surface of the support film (S) so that it can be transferred, an optical sheet with a functional layer can be obtained all at once.

[0043]

EXAMPLES The present invention will be further described with reference to examples.

Example 1 FIG. 1 is an explanatory view showing an example of the optical sheet of the present invention and a method for producing the same.

Thickness 1 as an example of the support film (S)
00μm polyester film (average surface roughness is 0.
Brominated phenoxy resin (“YPB” manufactured by Tohto Kasei Co., Ltd.) was applied to the smooth surface of a biaxially stretched polyethylene terephthalate film (“A-4100” manufactured by Toyobo Co., Ltd.) that was not subjected to corona discharge treatment and had a maximum size of 0.08 μm. -43
C)) with an adduct of tolylene diisocyanate and trimethylolpropane (“Coronate L” manufactured by Nippon Polyurethane Industry Co., Ltd.) mixed at a resin ratio of 100: 1, and a resin solution having a solid content of 36% by weight. After being cast, it is dried at a temperature of 70 to 130 ° C., and a temperature of 170 ° C.
The mixture was heated and cured at 60 ° C. for 60 minutes to form a hard and high softening point three-dimensional crosslinked body layer (H) having a thickness of 30 μm. The surface hardness of the three-dimensional crosslinked layer (H) having a high hardness and a high softening point is 3H and the heat distortion temperature is
It was 75 ° C. As a result, the first laminated film (L1) having a layer structure of (S) / (H) was obtained.

Substrate layer made of polycarbonate film
On both sides of (V1), an anti-translucency composition comprising a composition in which an N-methylolacrylamide-acrylic acid graft copolymer of polyvinyl alcohol is mixed with a methylolmelamine-based crosslinker via anchor coating layers (V2) and (V2). Gas resin layer
(V3), (V3) provided by the casting film forming method is the core material layer (V)
Prepared as The layer constitution and the thickness of each layer are as follows. (V) = (V3) / (V2) / (V1) / (V2) / (V3) = 10/1/50/1/10 (μm)

On one side of a pair of rolls arranged in parallel with a slight gap, the first laminated film (L1) obtained above had the three-dimensional hard-softening point three-dimensional crosslinked body layer (H) side facing upward. Supplied to. In addition, on the other roll, above core material layer (V)
Was supplied.

An epoxy acrylate-based highly viscous UV curable resin liquid as an example of the non-solvent type curable resin liquid (a) between the both rolls while rotating both rolls in a direction in which they bite each other when viewed from above. ("TUR-980" manufactured by Teikoku Chemical Industry Co., Ltd.) was discharged. As a result, since the ultraviolet curable resin liquid was sandwiched between the hard and high softening point three-dimensional crosslinked body layer (H) side of the first film (L1) and the core material layer (V), UV irradiation is performed under the conditions of an output of 120 W / cm, 1 lamp, a lamp distance of 200 mm, a line speed of 2 m / min, 1 pass, and a light amount of 600 mJ / cm ² , and the sandwiched UV-curable resin liquid layer is cured to a thickness of 43 μm. The adhesive layer (A) was composed of the curable resin cured product layer.

As a result, a second laminated film (L2) having a layer structure of (S) / (H) / (A) / (V) was obtained. (By peeling and removing the support film (S) from the second laminated film (L2), an optical sheet having a layer structure of (H) / (A) / (V) can be obtained.)

The second film (L2) obtained above was fed to one of a pair of rolls arranged in parallel with a slight gap so that the core material layer (V) side was the upper surface. Further, the first laminated film (L1) described above was supplied to the other roll so that the hard high-softening point three-dimensional crosslinked body layer (H) side was the upper surface.

An epoxy acrylate-based highly viscous ultraviolet curable resin liquid as an example of the non-solvent type curable resin liquid (a) between the two rolls while rotating both rolls in a direction in which they bite each other when viewed from above. ("TUR-980" manufactured by Teikoku Chemical Industry Co., Ltd.) was discharged. As a result, the UV-curable resin liquid was added to the core material layer (V) of the second film (L2).
Sandwiched between the side and the 3D crosslinked layer (H) side of the hardened and softened point of the first laminated film (L1), output 120W / cm, 1 lamp, lamp distance 200mm, line Ultraviolet irradiation is performed under the conditions of a speed of 2 m / min, 1 pass, and a light amount of 600 mJ / cm ² to cure the sandwiched UV curable resin liquid layer, and an adhesive layer composed of a curable resin cured material layer having a thickness of 41 μm ( A)

As a result, (S) / (H) / (A) / (V) / (A) / (H) /
Since the third laminated film (L3) having the layer structure of (S) was obtained, only the support films (S) on both sides were peeled off from the third laminated film (L3), and (H) / (A A target optical sheet having a layer structure of) / (V) / (A) / (H) was obtained. The peeling and removal of the support film (S) was smooth.

The surface roughness of the hard high-softening point three-dimensional crosslinked body layer (H) constituting both outer layers of the obtained optical sheet was 0.08 as measured by a non-contact type surface roughness meter utilizing light interference. μm
(That is, ± 0.04 μm). The optical sheet had a thickness of 215 μm, a retardation value of 7 nm, a visible light transmittance of 88%, and an oxygen transmittance (measured according to ASTM D-1434-75) of 0.1 cc / 24 hr · m ² · atm. Hereinafter, the pencil hardness of the surface was 3H.

Next, a transparent electrode of ITO having a thickness of 700 angstrom was formed on one surface of this optical sheet by a sputtering method. In this case, the adhesion of the ITO layer was good without any treatment on the surface of the optical sheet. After forming the transparent electrode, a patterned electrode was formed according to a conventional method.

After a liquid crystal cell was produced using this substrate made of an optical sheet with a pattern electrode, a collective connection was made between the pattern electrode and the outer lead of the IC for control, and an anisotropic conductive sheet was provided between them. 150 ℃ × with interposition
It was carried out by thermocompression bonding under the condition of 0.5MPa x 10 seconds, but during the thermocompression bonding, the conductive particles did not dwarf and the phenomenon that the electrode substrate deformed concavely at the conductive agent particles was not seen. (That is, the conductive particles did not penetrate into the electrode substrate), and as a result, damage defects such as cracks did not occur on the pattern electrode.

Example 2 As an example of the support film (S), a polyester film having a thickness of 100 μm (a biaxially stretched polyethylene terephthalate film having an average surface roughness of 0.04 μm and a maximum of 0.08 μm (“Super” manufactured by Teijin Limited) Phenoxy resin ("YP50" manufactured by Tohto Kasei Co., Ltd.)
CD30 ") with an adduct of tolylene diisocyanate and trimethylolpropane (" Coronate L "manufactured by Nippon Polyurethane Industry Co., Ltd.) at a resin ratio of 100: 2.
After casting a resin solution having a solid content of 30% by weight mixed at a weight ratio of, the mixture was dried at a temperature of 70 to 130 ° C.
It was heated and cured at 0 ° C. for 60 minutes to form a hard and high softening point three-dimensional crosslinked body layer (H) having a thickness of 25 μm. This allows
The first laminated film (L1) having a layer structure of (S) / (H) was obtained.

Thereafter, in the same manner as in Example 1, (H) / (A) / (V) /
An objective optical sheet having a layer structure of (A) / (H) was obtained.
The surface hardness of the three-dimensional hard-softened three-dimensional crosslinked layer (H) constituting both outer layers was 4H, and the heat distortion temperature was 165 ° C. Forming an ITO layer on this optical sheet, forming a pattern electrode,
A liquid crystal cell was produced and the pattern electrodes and the outer leads of the control IC were collectively connected with the anisotropic conductive sheet interposed, and good results similar to those of Example 1 were obtained.

Example 3 As an example of the support film (S), a polyester film having a thickness of 100 μm (a biaxially stretched polyethylene terephthalate film having an average surface roughness of 0.05 μm and a maximum of 0.08 μm (“O manufactured by Teijin Limited” Type)), an epoxy acrylate resin (“TUR1680” manufactured by Teikoku Chemical Industry Co., Ltd.) and an adduct of tolylene diisocyanate and trimethylolpropane (“Coronate L” manufactured by Nippon Polyurethane Industry Co., Ltd.) on the smooth surface 5 by the ratio
After casting a resin solution having a solid content of 52% by weight mixed in a weight ratio of 0: 3, the resin solution was dried at a temperature of 60 ° C., and then the integrated light amount was 1
Irradiated with ultraviolet rays under the condition of 000mJ / cm ^2, the temperature further 1
It was heated and cured at 30 ° C. for 30 minutes to form a hard and high softening point three-dimensional crosslinked body layer (H) having a thickness of 62 μm. As a result, the first laminated film (L1) having a layer structure of (S) / (H) was obtained.

Thereafter, in the same manner as in Example 1, (H) / (A) / (V) /
An objective optical sheet having a layer structure of (A) / (H) was obtained.
The surface hardness of the three-dimensional hardened and softened crosslinked layer (H) constituting both outer layers was 4H and the heat distortion temperature was 200 ° C. Forming an ITO layer on this optical sheet, forming a pattern electrode,
A liquid crystal cell was produced and the pattern electrodes and the outer leads of the control IC were collectively connected with the anisotropic conductive sheet interposed, and good results similar to those of Example 1 were obtained.

[0060]

EFFECTS OF THE INVENTION According to the present invention, the retardation value is small, it can be easily made thick, the thermal dimensional stability is high, and it can be freely applied to not only small and medium size TN or STN liquid crystal electrode substrates. It is possible to deal with this, and it is advantageous in terms of industrial productivity, and an optical sheet having excellent surface smoothness can be easily produced.

The optical sheet includes a pattern electrode and a control IC with an anisotropic conductive sheet interposed.
The outer leads of the above were collectively connected by thermocompression bonding .
Sometimes , no trouble occurs.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an example of an optical sheet of the present invention and a method for producing the same.

[Explanation of symbols]

(L1) ... first laminated film, (L2) ... second laminated film, (L3) ... third laminated film, (S) ... support film, (H) ... hard and high softening point tertiary composed of non-imide resin Original crosslinked body layer, (V) ... Core material layer, (V1) ... Base material layer, (V2) ... Anchor coating layer, (V3) ...
Air-permeable resin layer, (A) ... Adhesive layer composed of non-solvent type curable resin cured product, (a) ... Non-solvent type curable resin liquid

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hirotoshi Terui 1-4-4 Nihonbashi Bakuro-cho, Chuo-ku, Tokyo Fujimori Industry Co., Ltd. (56) Reference JP-A-5-57857 (JP, A) JP-A 5-241180 (JP, A) JP-A-4-299313 (JP, A) JP-A-6-64103 (JP, A) JP-A-53-2577 (JP, A) Actual development-Sho 63-146823 (JP, U) Actual development Sho 59-17922 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) G02F 1/1333 G02F 1/13 101 G02F 1/1343 G02F 1/1345 B29D 9/00 B32D 1/00-35/00

Claims (6)

(57) [Claims] 1. An optical sheet made of plastics is electrically charged.
When used as a polar substrate, the pattern electrode and the control I
Anisotropic conduction between the outer lead of C and the outer lead
Performed by a method of thermocompression bonding with an electric sheet interposed
An optical sheet for use as an adhesive layer comprising a non-solvent type curable resin cured product layer on at least one surface of a single-layer or multi-layer core material layer (V).
Via (A), a three-dimensional crosslinked layer of hard and high softening point made of a non-imide resin having a surface hardness of H or higher according to JIS K5400 (load of 100 g) and a heat distortion temperature of 130 ° C. or higher determined by the heat sag method ( H) is a laminated optical sheet. 2. The optical sheet according to claim 1, wherein the single-layer or multi-layer core material layer (V) is a layer having a gas barrier property. 3. The optical sheet according to claim 1, wherein the adhesive layer (A) is an active energy ray-curable resin cured product layer or a thermosetting resin cured product layer. 4. The optical sheet according to claim 1, wherein the optical sheet is an electrode substrate for a liquid crystal display panel. 5. An optical sheet made of plastics is electrically charged.
When used as a polar substrate, the pattern electrode and the control I
Anisotropic conduction between the outer lead of C and the outer lead
Performed by a method of thermocompression bonding with an electric sheet interposed
A method for manufacturing an optical sheet for use in a method for producing an optical sheet according to JIS K5400 (load 1
00g) has a hardness of H or higher and a heat distortion temperature of 130 ° C. or higher as determined by the heat sag method. By forming a hard and high softening point three-dimensional crosslinked layer (H) made of a non-imide resin, (S) / First laminated film (L) having a layer structure of (H)
Step A of preparing 1), Step B of preparing a single-layer or multi-layer core material layer (V), the three-dimensional hard-softening point three-dimensional crosslinked body layer (H) side of the first laminated film (L1) and the above A non-solvent type curable resin liquid (a) is supplied between the core material layer (V) and a curable resin liquid (a) between the first laminated film (L1) and the core material layer (V). Adhesive layer consisting of a curable resin cured product layer that is cured by sandwiching the layer
(A) and step C for obtaining a second laminated film (L2) having a layer structure of (S) / (H) / (A) / (V) Manufacturing method. 6. After step C, between the core layer (V) side of the second laminated film (L2) and the hard and softening point three-dimensional crosslinked body layer (H) side of the first laminated film (L1). The non-solvent type curable resin liquid (a) is supplied to and the layer of the curable resin liquid (a) is sandwiched between the second laminated film (L2) and the first laminated film (L1). Adhesive layer consisting of cured resin layer
By making (A), (S) / (H) / (A) / (V) / (A) / (H) / (S)
The step D of obtaining a third laminated film (L3) having the layer structure of 1. is carried out, and the method for producing an optical sheet according to claim 5.