JPH04299109A - Optical laminate - Google Patents

Abstract

PURPOSE:To provide antistatic technique generating no problem not only in a laminate manufacturing process and a handling process but also in a post- treatment process such as a vacuum membrane forming process in a laminate containing the laminating units of an air impermeable resin layer and a crosslinkable resin cured layer. CONSTITUTION:Air impermeable resin layers (2) composed of an ethylene/vinyl alcohol copolymer having a polymeric antistatic agent internally added thereto are formed on an optically isotropic base material sheet layer 1 through anchor coating layers (ac) by a casting method and, subsequently, a crosslinkable resin cured layer (3) composed of a phenoxyether resin having a polyisocyanate compound compounded therewith is formed thereon.

Description

[Detailed description of the invention]

0001

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

0002

[Prior Art] Glass has conventionally been used as an electrode substrate for liquid crystal display panels, but it is heavy and
Recently, plastic substrates have become popular because they have problems such as not being able to be made thin, easily damaged, and difficult to mass produce.

The present applicant also provided an air permeable resin layer (2) on at least one side of the optically isotropic base sheet layer (1) via an anchor coating layer (ac), and further provided the air permeable resin layer (2) on at least one side of the optically isotropic base sheet layer (1). 2) A crosslinkable resin cured material layer on top (
3) A patent application has been filed as JP-A-63-71829 for an electrode substrate for a liquid crystal display panel having the above structure, and it has already been put into practical use.

[0004] Also related to the application of the present applicant, Japanese Patent Laid-Open No. 64-50021 discloses a two-layer laminated film consisting of an air-permeable resin layer (2)/a crosslinkable resin cured material layer (3). There is a disclosure of an electrode substrate for a liquid crystal display panel in which the air-permeable resin layers (2) are integrally laminated via an adhesive layer (ad) in a state where they face each other, and Japanese Patent Application Laid-Open No. 64-5
Publication No. 0022 discloses an electrode substrate for a liquid crystal display panel having the following structure: crosslinkable resin cured layer (3)/air permeable resin layer (2)/crosslinkable resin cured layer (3).

[0005]

[Problems to be Solved by the Invention] Now, the optically isotropic base material sheet layer (1), the air permeable resin layer (2), the crosslinkable resin cured material layer (3), and the anchor coating layer (a).
c), when the adhesive layer is (ad), the above-mentioned JP-A No. 6
3-71829, JP 64-50021, JP 64-50022, (3)/(2)/(ac)/(1), (3)/(2)/ (ac)/(1)/(ac)/(2)
/(3) ,(3)/(2)/(ad)/(2)/(3
), (3)/(2)/(3) Optical laminates having the following layer configurations are shown.

[0006] When these optical laminates are used as electrode substrates for liquid crystal display panels, a layer of ITO or the like is coated on the outermost crosslinkable resin cured material layer (3) by a vacuum thin film forming method such as sputtering. It is necessary to form a transparent electrode.

However, all of the above optical laminates are easily charged, so even if they are manufactured and subsequently handled in a clean room, dust may adhere to the surface of the outermost crosslinkable resin cured material layer (3). However, as a result, the optical properties may be reduced or the adhesion of the transparent electrode may be partially reduced.

In order to prevent such troubles, the present inventors have considered adding an antistatic agent internally to the outermost crosslinkable resin cured material layer (3), but the temperature and Under vacuum conditions, the antistatic agent added internally migrates to the surface of the cured crosslinkable resin layer (3) and evaporates from the surface, which may reduce the degree of vacuum or impair the adhesion of the transparent electrode. I was faced with a new problem.

[0009] Against this background, the present invention provides a laminate including a laminated unit of an air-permeable resin layer (2)/a crosslinkable resin cured material layer (3), and provides improvements in the manufacturing process and handling of the laminate. The purpose of this invention is to provide an antistatic technique that does not cause problems in subsequent post-processing steps such as vacuum thin film forming steps.

0010

[Means for Solving the Problems] The optical laminate of the present invention is a laminate comprising an air-permeable resin layer (2) formed by a casting method and a crosslinkable resin cured material layer (3) formed by a casting method on top of the air-permeable resin layer (2) formed by a casting method. The laminate including the unit is characterized in that an effective amount of an antistatic agent is internally added to the air-permeable resin layer (2).

The present invention will be explained in detail below.

Air-permeable resin layer (2) Air-permeable resin layer (2) refers to its oxygen permeability ASTM
Measured according to D-1434-75) is 30cc/24
hr・m2・atm or less, preferably 20cc/24
Refers to a resin layer that is hr・m2・atm or less.

[0013] Such a resin layer is a layer formed from a polymer containing 50 mol% or more of a vinyl alcohol component, particularly a layer formed from a polymer containing polyvinyl alcohol or a copolymerized modified product or graft product thereof, and a polymer having an ethylene content of 15 to 50%. Vinyl alcohol based resin layers such as mol% ethylene-vinyl alcohol copolymers, especially ethylene-vinyl alcohol copolymer layers are preferred. In addition, a layer formed from a polymer containing 50 mol% or more of an acrylonitrile component or a vinylidene halide component can also be used.

[0014] The thickness of the air permeable resin layer (2) is usually 1
It is set in the range of ~50 μm, preferably 2 ~ 20 μm. If the thickness is less than 1 μm, the air permeability will be insufficient, and if the thickness is increased more than necessary, the visible light transmittance will decrease and the moisture resistance will decrease, which is disadvantageous in practice.

Crosslinkable resin cured product layer (3) The crosslinkable resin cured product layer (3) is preferably made of phenoxy ether type crosslinkable resin, epoxy resin, acrylic resin, acrylic epoxy resin, melamine resin, phenol resin, or urethane resin. It is composed of a cured product of crosslinkable resin selected from resins. Among the crosslinkable resins, a particularly preferred resin is a phenoxyether type crosslinked polymer represented by the following chemical formula 1, in which the hydrogen moiety of the hydroxyl group of the phenoxyether type polymer is subjected to a crosslinking reaction with a polyfunctional compound.

[0016]

[Chemical formula 1]

(In the formula, R1 to R6 are each hydrogen, a lower alkyl group having 1 to 3 carbon atoms, or Br, R7
represents a lower alkylene group having 2 to 4 carbon atoms, m represents an integer of 0 to 3, and n represents an integer of 20 to 300, respectively. )

0
[018] The polyfunctional compound (crosslinking agent) to be reacted in order to obtain a crosslinked polymer is a group having high reaction activity with a hydroxyl group, such as an isocyanate group, a carboxyl group, or a reactive inducing group in a carboxyl group (for example, Examples include compounds having two or more of the same or different mercapto groups (halide, active amide, active ester, acid anhydride group, etc.), and isocyanate groups are particularly important.

The thickness of the cured crosslinkable resin layer (3) is usually set in the range of 2 to 100 μm, preferably 5 μm to 50 μm.

Antistatic agent The antistatic agent added internally in the air-permeable resin layer (2) includes surfactants such as primary amine salts, tertiary amines, quaternary ammonium compounds, and pyridine derivatives. Cationic surfactants such as sulfated oils, soaps, sulfated ester oils, sulfated amide oils, olefin sulfate ester salts, fatty alcohol sulfate ester salts, alkyl sulfate ester salts, aliphatic ethyl sulfonates, alkyl sulfonic acids salts, alkylnaphthalene sulfonates, alkylbenzene sulfonates, mixtures of naphthalene sulfonic acid and formaldehyde, succinic ester sulfonates,
Anionic surfactants such as phosphate ester salts; partial fatty acid esters of polyhydric alcohols, ethylene oxide adducts of fatty alcohols, ethylene oxide adducts of fatty acids, ethylene oxide adducts of fatty acid aminos or fatty acid amides, ethylene oxide adducts of alkylphenols Examples include nonionic surfactants such as ethylene oxide adducts of alkylnaphthols, ethylene oxide adducts of partial fatty acid esters of polyhydric alcohols; and amphoteric surfactants such as carboxylic acid derivatives and imidazoline derivatives.

[0021] Antistatic agents other than surfactants include quaternized acrylic polymers, styrene polymers with sulfonic acid groups introduced, quaternized polyamide polymers, and vinyl alcohol components of 50 mol% or more. Examples include polymers in which a monomer containing a sulfonic acid group, an amino group, or a quaternary ammonium group is introduced by copolymerization or graft polymerization.

The antistatic agent has the desired antistatic property (
For example, the above-mentioned materials can be used alone or in combination of two or more, as long as they exhibit a surface resistivity of 1012 Ωcm or less.
Those that reduce the visible light transmittance to, for example, 50% or less are excluded. Comparing surfactant-based antistatic agents and polymer-based antistatic agents, the use of polymer-based antistatic agents is advantageous in terms of preventing migration (transfer to the surface) and preventing volatilization under high temperature conditions. In Although,
In that case as well, it may be preferable to use an appropriate amount of a surfactant-based antistatic agent.

[0023] The amount of antistatic agent added is an effective amount that exhibits the required antistatic property, but
It is often made to account for about 0.5 to 20% by weight.

Optically isotropic base sheet layer (1) In the optical laminate of the present invention, the air permeable resin layer (2) is placed directly on the optically isotropic base sheet layer (1) or as an anchor coating layer ( ac).

Optically isotropic base sheet layer (1) in this case
Examples include layers formed from resins such as polyarylene ester, polycarbonate, polysulfone, polyethersulfone, amorphous polyolefin having a bicyclo group, polystyrene, and polyparabanic acid resin.

The thickness of the optically isotropic base sheet layer (1) is:
Usually 25 to 500 μm, preferably 30 to 200 μm
However, it is not necessarily limited to this range.

The retardation value of the optically isotropic base sheet layer (1) is desirably 30 nm or less, particularly 20 nm or less. If the retardation value exceeds 30 nm, the appropriate viewing angle for the panel becomes narrow, interference fringes occur, and the readability deteriorates when used as a liquid crystal display panel.

When the optically isotropic base sheet layer (1) does not have solvent resistance, the anchor coating layer (ac)
It is preferable to use a layer formed from an aqueous or alcohol-based anchor coating agent.

Optical Laminate The optical laminate of the present invention includes a laminated unit in which a crosslinkable resin cured material layer (3) is provided on an air-permeable resin layer (2). Since the air-permeable resin layer (2) and the crosslinkable resin cured material layer (3) need to have optical isotropy, both are formed by a casting method that does not cause molecular orientation.

That is, the optically isotropic base sheet layer (1)
When using an air-permeable resin layer (2), an air-permeable resin layer (2) is formed on at least one side of the optically isotropic base sheet layer (1) by a casting method, and an air-permeable resin layer (2) is further formed on the air-permeable resin layer (2) by a casting method. A crosslinkable resin cured material layer (3) is formed. Formation of the cured crosslinkable resin layer (3) requires not only drying but also heat curing. The thus obtained laminate is coated with an adhesive layer (ad
) can also be stacked.

When the optically isotropic base sheet layer (1) is not used, the air-permeable resin layer (2) is formed by a casting method on a suitable support such as a polyester film, stainless steel surface, or drum surface. , and further the air permeable resin layer (
2) After forming a crosslinkable resin cured material layer (3) on top by a casting method, peel the laminate of air permeable resin layer (2)/crosslinkable resin cured material layer (3) from the support. . This laminate can also be laminated with an adhesive layer (ad) in between so that the air-permeable resin layers (2) face each other. Furthermore, a crosslinkable resin cured material layer (3) may be further provided on the air permeable resin layer (2) side of the laminate of the air permeable resin layer (2)/crosslinkable resin cured material layer (3).

[0032] Furthermore, an adhesive layer (ad) is generally provided at the interface between the air-permeable resin layer (2) and the crosslinkable resin cured material layer (3).
It is not enough to establish a This is because if the cured crosslinked resin layer (3) is formed from a phenoxy ether type crosslinked polymer and the air permeable resin layer (2) is formed from a vinyl alcohol resin, the cured crosslinked resin layer (3) This is because the crosslinking agent used during formation also reacts with the functional groups of the air-permeable resin layer (2), so that strong adhesion between both layers is achieved.

Ultimately, the optical laminate of the present invention comprises (1) an optically isotropic base sheet layer, (2) an air-permeable resin layer, (3) a cured crosslinkable resin layer, and an anchor coating layer. When (ac) and the adhesive layer are (ad), ・ (3) / (2) / (ac) / (1) , ・ (3)
/(2)/(ac)/(1)/(ac)/(2)/(3
),・(3)/(2)/(ac)/(1)/(ad)
/(1)/(ac)/(2)/(3) ,・(3)/
(2)/(ac)/(1)/(ac)/(2)/(3)
/(ad)/(3)/(2)/(ac)/(1)/(a
c)/(2)/(3) ,・(3)/(2)/(ad
)/(2)/(3), (3)/(2)/(3), and (3)/(2). Note that the anchor coating layer (ac) can also be omitted.

Applications The optical laminate of the present invention is particularly useful as an electrode substrate for liquid crystal display panels, and can also be used for various other purposes such as recording devices and display devices.

In these applications, ITO or other transparent electrodes are provided on the surface of the optical laminate. Vacuum thin film forming methods such as vacuum evaporation, sputtering, and ion plating are preferably used to form the transparent electrode, and metal spraying, metal plating, chemical vapor deposition,
A spray method etc. can also be adopted.

[0036]

[Operations and Effects of the Invention] In the optical laminate of the present invention having the above structure, the crosslinkable resin cured material layer (3) located at the outermost layer is not used, but the air permeable resin located inside the crosslinkable resin cured material layer (3). An effective amount of antistatic agent is incorporated internally into layer (2). Even if the antistatic agent is internally added to the inner layer in this way, the surface of the laminate exhibits the necessary antistatic properties.

[0037] Furthermore, since the air-permeable resin layer (2) contains polar groups such as OH groups, it exhibits strong affinity with antistatic agents.
Even if the laminate is brought under high temperature conditions or vacuum conditions, the added antistatic agent will not affect the crosslinkable resin cured material layer (3), which is the outer layer.
) is small.

Therefore, the optical laminate of the present invention does not cause troubles due to charging during its manufacturing process and handling, and when a transparent electrode such as ITO is formed on the surface of the laminate by a vacuum thin film formation method, Even in this case, troubles such as a decrease in the degree of vacuum and a decrease in the adhesion of the transparent electrode due to migration and volatilization of the antistatic agent are unlikely to occur.

In the optical laminate of the present invention including the laminated unit of air-permeable resin layer (2)/crosslinkable resin cured material layer (3), the crosslinkable resin cured material layer (3) serving as the outermost layer )
has excellent scratch resistance, high hardness, and good chemical resistance, and also has excellent adhesion to transparent electrodes such as ITO without special treatment. Air permeable resin layer (2)
has excellent oxygen barrier properties, and when used as an electrode substrate for a liquid crystal display panel, it greatly contributes to extending the life of the encapsulated liquid crystal.

The cured cross-linked resin layer (3) is brittle when used alone, and the air-permeable resin layer (2) may have moisture permeability when used alone, but since both layers are laminated adjacent to each other, The brittleness of the cross-linked resin cured material layer (3) is compensated by the air-permeable resin layer (2), and the moisture permeability of the air-permeable resin layer (2) is compensated by the cross-linked resin cured material layer (3). Ru.

As described above, the optical laminate of the present invention makes use of the light weight and workability of a plastic substrate, while providing performance comparable to that of a glass substrate.

[0042]

[Examples] Next, the present invention will be further explained with reference to Examples. Hereinafter, "parts" refer to parts by weight.

Example 1 FIG. 1 is a sectional view showing one example of the optical laminate of the present invention, and FIG. 2 is a sectional view showing another example of the optical laminate of the invention.

[0044] One side of a polyarylene ester film having a thickness of 50 μm and a retardation value of 9 nm, as an example of the optically isotropic base sheet layer (1), is coated with an aqueous polyester urethane anchor coating agent, and then dried to reduce the thickness. An anchor coating layer (ac) with a thickness of 2 μm was formed.

[0045] Next, this anchor coating layer (a
From above c), 20 parts of ethylene-vinyl alcohol copolymer with an ethylene content of 32 mol%, 45 parts of water, 55 parts of n-propanol, 2 parts of methylolated melamine (Sumitec M-3 manufactured by Sumitomo Chemical Co., Ltd.), A resin liquid having a composition of 4 parts of a graft copolymer obtained by graft polymerizing dimethylaminoethyl methacrylate to an ethylene-vinyl alcohol copolymer having the same copolymer composition as above was cast and dried in a dryer at a temperature of 110°C. Passed and dried. As a result, a 12 μm thick antistatic agent-containing air-permeable resin layer (2) was formed.

Next, from above this air-permeable resin layer (2), 40 parts of phenoxy ether resin, 40 parts of methyl ethyl ketone, 20 parts of cellosolve acetate, and a 75% by weight solution of an adduct of tolylene diisocyanate and trimethylolpropane were added. (Coronate L manufactured by Nippon Polyurethane Co., Ltd.) A resin solution having a composition of 40 parts was cast at 80°C.
After drying for 4 minutes, heat at 130℃ for 20 minutes,
A cured crosslinkable resin layer (3) having a thickness of 10 μm was formed. As a result, the laminate shown in FIG. 1 was obtained.

Similarly, from the other side of the optically isotropic base sheet layer (1), the anchor coating layer (a
c), an antistatic resin layer containing an antistatic agent (2), and a cured crosslinkable resin layer (3) were formed in this order.

[0048] As a result, (3)/(2)/(ac)/
A laminate shown in FIG. 2 having a layer structure of (1)/(ac)/(2)/(3) was obtained. The thickness of this laminate is 98 μm
, retardation value is 10 nm, visible light transmittance is 86%, oxygen transmittance (measured according to ASTM D-1434-75) is 0.1cc/24hr・m2・atm
The pencil hardness of the surface was 2H. After rubbing this laminate five times with a cloth, an ash test was conducted by bringing the laminate close to cigarette ash, but no matter how close the laminate was to the ash, no ash adhered to the laminate at all.

Next, the surface of the cured crosslinkable resin layer (3) on one side of the laminate obtained above was coated with ITO to a thickness of 500 mm.
An angstrom transparent electrode was formed by sputtering. Even though no treatment was performed on the cured crosslinkable resin layer (3), the adhesion of the ITO layer was extremely good, and no lack of adhesion was observed in any part.

Example 2 FIG. 3 is a sectional view showing still another example of the optical laminate of the present invention.

On one side of a 100 μm thick polyester film as a support, 20 parts of an ethylene-vinyl alcohol copolymer with an ethylene content of 32 mol % and 3 parts of 2-acrylamide-2-methylpropanesulfonic acid were graft-polymerized. 23 parts of graft polymer composition, 45 parts of water,
A composition consisting of 55 parts of n-propanol, 1 part of methylolated melamine (Sumitec M-3, manufactured by Sumitomo Chemical Co., Ltd.), and 1 part of a cationic surfactant-based antistatic agent (Anstex C-200, manufactured by Toho Chemical Co., Ltd.). The resin liquid was cast and dried by passing through a dryer at a temperature of 110°C. As a result, a 10 μm thick antistatic agent-containing air-permeable resin layer (2) was formed.

Next, from above this air-permeable resin layer (2), 40 parts of brominated phenoxy ether resin, 40 parts of methyl ethyl ketone, 20 parts of cellosolve acetate, and 75 parts by weight of an adduct of tolylene diisocyanate and trimethylolpropane were added. % solution (Coronate L manufactured by Nippon Polyurethane Co., Ltd.) with a composition of 40 parts,
After drying at 80°C for 4 minutes, it was heated at 130°C for 20 minutes to form a cured crosslinkable resin layer (3) with a thickness of 15 μm.

Two sets of such laminates are prepared, and for one of them, the laminate of the air-permeable resin layer (2) and the cured crosslinkable resin layer (3) is peeled off from the support. An epoxy adhesive solution was applied to the air-permeable resin layer (2) surface. Regarding the other side, the laminate of the air-permeable resin layer (2) and the crosslinkable resin cured material layer (3) was peeled off from the support.

[0054] These laminates were bonded together through a group of heating rolls while stacking each other so that the air-permeable resin layer (2) surface of the latter laminate faced the adhesive solution coated surface of the former laminate. .

[0055] As a result, (3)/(2)/(ad)/
The laminate shown in FIG. 3 having a layer structure of (2)/(3) was obtained. The thickness of this laminate is 60 μm, the retardation value is 3 nm, the visible light transmittance is 92%, and the oxygen transmittance (A
(measured according to STM D-1434-75) is 0.1
cc/24hr・m2・atm, surface pencil hardness is 2H
Met. After rubbing this laminate five times with a cloth, an ash test was conducted by bringing the laminate close to cigarette ash, but no matter how close the laminate was to the ash, no ash adhered to the laminate at all.

Next, the surface of the cured crosslinkable resin layer (3) on one side of the laminate obtained above was coated with ITO to a thickness of 450 mm.
An angstrom transparent electrode was formed by sputtering. Although no treatment was performed on the cured crosslinked resin layer (3), the adhesion of the ITO layer was extremely good, and no lack of adhesion was observed in any part.

Example 3 FIG. 4 is a sectional view showing another example of the optical laminate of the present invention.

On one side of a 100 μm thick polyester film as a support, 20 parts of ethylene-vinyl alcohol copolymer with an ethylene content of 32 mol%, 45 parts of water,
A resin solution consisting of 55 parts of n-propanol and 2 parts of an anionic/nonionic surfactant-based antistatic agent (Resistat 212 manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) was cast and passed through a dryer at a temperature of 110°C. Let it dry. As a result, a 10 μm thick air-permeable resin layer containing an antistatic agent (
2) was formed.

Next, from above this air-permeable resin layer (2), 40 parts of phenoxy ether resin, 40 parts of methyl ethyl ketone, 20 parts of cellosolve acetate, and a 75% by weight solution of an adduct of tolylene diisocyanate and trimethylolpropane were added. (Coronate L manufactured by Nippon Polyurethane Co., Ltd.) A resin solution having a composition of 40 parts was cast at 80°C.
After drying for 4 minutes, heat at 130℃ for 20 minutes,
A cured crosslinkable resin layer (3) having a thickness of 15 μm was formed.

By peeling the laminate of the air-permeable resin layer (2) and the crosslinkable cured resin layer (3) from the support, the laminate shown in FIG. 4 having the layer structure of (2)/(3) is obtained. I got a body. After rubbing this laminate with a cloth five times from the side of the cured cross-linked resin layer (3), we conducted an ash test in which the laminate was brought close to cigarette ash, but no matter how close the laminate was to the ash, no ash remained in the laminate. It did not adhere to the body.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an example of an optical laminate of the present invention.

FIG. 2 is a sectional view showing another example of the optical laminate of the present invention.

FIG. 3 is a sectional view showing still another example of the optical laminate of the present invention.

FIG. 4 is a sectional view showing another example of the optical laminate of the present invention.

[Explanation of symbols]

(1)...Optically isotropic base sheet layer (2)...Air-permeable resin layer (3)...Crosslinkable resin cured material layer (ac)...Anchor coating layer (ad)...adhesive layer

Claims (3)

[Claims] 1. A laminate comprising a laminated unit comprising an air permeable resin layer (2) formed by a casting method and a crosslinkable resin cured material layer (3) formed by a casting method on top of the air permeable resin layer (2). (
2) An optical laminate characterized in that an effective amount of an antistatic agent is internally added therein. 2. The optical laminate according to claim 1, wherein the air-permeable resin layer (2) is provided on the optically isotropic base sheet layer (1) directly or via an anchor coating layer (ac). Claim 3: Claim 1, which is an electrode substrate for a liquid crystal display panel.
Or the optical laminate according to 2.