JP2000296595A - Optical easily adhesive film and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide high transparency and easily adhesive properties and also enhance anti-scratch properties in an after-process such as AR process by adding a copolymer polyester resin and a copolymer polyurethane resin which are composed of a branched monomer as a main resin constituent to an easily adhesive layer. SOLUTION: An easily adhesive layer is formed on the surface of a polyester base material film. In this case, a copolymer polyester resin and a copolymer polyurethane resin which are composed of a branched monomer as a constituent are added to the easily adhesive layer. When the coefficient of static friction and the coefficient of dynamic friction between the obtained easily adhesive layer face and the likewise obtained polyester base material film face are set to be 0.50 or less and 0.45 or less respectively, while the total light transmittance to a visible light is maintained at 90% or more by adding fine particles to the easily adhesive layer, the anti-scratch properties can be improved. Further, when the fine particles are made up of particles with 20-150 nm or below average particle diameter and particles with 150-1,000 nm or less average particle diameter, it is possible to appropriately control the coefficient of friction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an easy-to-use optically-adhesive film having an easily-adhesive layer formed on both sides of a polyester-based base film and suitable for various optical uses, and a method for producing the film.

[0002]

2. Description of the Related Art Polyester films, particularly biaxially oriented polyester films, are widely used as various optical films because of their excellent transparency, dimensional stability and chemical resistance. For example, a base film for a prism lens sheet, a base film for a touch panel, a base film for a backlight, a base film for an AR (anti-reflection) film, and a CRT used for a liquid crystal display device.
Since the application of the crush prevention film for use requires excellent strength and dimensional stability, a relatively thick film having a thickness of 100 μm or more is suitably used.

[0003] The film used for such an optical film is required to have excellent transparency and to have excellent adhesion to prism lens processing, hard coating processing and AR processing. In addition, since minute scratches on the film surface are also optical defects, it is desired that the scratches be as small as possible.

[0004]

However, it is generally known that a polyester film has poor adhesion to other materials, such as a prism lens mainly composed of an acrylic resin or a hard coat. For this reason, various types have been proposed in which an easy-adhesion layer made of a polyurethane resin or the like is formed on the surface of a polyester film (for example, JP-A-6-340049).

[0005] However, when an easy-adhesion layer made of a polyurethane resin is formed, the adhesion to an outer layer such as a hard coat layer is improved, but the adhesion to a polyester film as a base material is not sufficient. However, there is a problem that sufficient adhesion to the outer layer cannot be obtained.

On the other hand, inorganic fine particles and the like are generally added to the base film in order to improve the slipperiness (easy slipperiness), but these particles tend to impair the transparency. Furthermore, the above-mentioned particles are not contained in the base material film, or when the addition amount is small enough not to inhibit the transparency, it is generally necessary to add particles for the purpose of imparting lubricity to the easy-adhesion layer. In order to ensure transparency, it is necessary to use particles having an extremely small average particle size equal to or less than the wavelength of visible light.

[0007] However, although only such fine particles having a small average particle size can ensure transparency, the film surface is easily scratched by a contacting roll in a subsequent step such as an AR processing step (hereinafter referred to as scratch resistance). The shortcoming, called sex, has recently become a problem.

In view of the above problems, an object of the present invention is to provide a highly transparent and excellent adhesive property, and
An object of the present invention is to provide an easy-to-use optical adhesive film having excellent scratch resistance in a post-process such as a processing process, and a method for producing the film.

[0009]

Means for Solving the Problems The present inventors have made intensive studies to achieve the above object, and as a result, have formed an easily adhesive layer using a specific copolymerized polyester resin and a polyurethane resin. As a result, it has been found that a film having high transparency and excellent adhesiveness can be obtained. Furthermore, it has been found that by blending specific fine particles in the easy-adhesion layer, it is possible to improve the scratch resistance in a subsequent step while maintaining high transparency, and have completed the present invention.

That is, the optically easy-to-use adhesive film of the present invention comprises:
In the easy-adhesion film for optics, wherein the easy-adhesion layer is formed on both surfaces of the polyester base film, the easy-adhesion layer is a main resin component, a copolymerized polyester resin containing a branching monomer as a constituent component, and polyurethane. It is characterized by containing a base resin.

In the above, by including fine particles in the easy-adhesion layer, the total light transmittance with respect to visible light is reduced to 90%.
% While maintaining the coefficient of static friction (μs) between the obtained easy-adhesion layer surface and the polyester-based substrate film surface at 0.1% or more.
Preferably, the dynamic friction coefficient (μd) is set to 0.45 or less. Here, the total light transmittance, the static friction coefficient, and the dynamic friction coefficient are values evaluated by the evaluation methods in the examples.

At this time, the fine particles have an average particle diameter of 20 nm.
It is preferable that the particles include particles having a size of not less than 150 nm and particles having an average particle size of not less than 150 nm and not more than 1000 nm.

On the other hand, in the production method of the present invention, a polyester-based resin film containing a branched monomer as a component and a water-soluble polyurethane-based resin having a blocked isocyanate group are contained on the surface of a polyester-based base film. After the application of the aqueous coating liquid, the coating is cured by heating to form an easily adhesive layer.

In the above, the aqueous coating liquid comprises particles having an average particle size of 20 nm or more and less than 150 nm,
It is preferable that the particles include particles of 0 nm or more and 1000 nm or less.

[Effects] According to the easy-to-use optical adhesive film of the present invention, as shown in the results of the examples, a specific copolymer polyester resin and a polyurethane resin are contained in the easy-adhesion layer, so that high transparency is achieved. Has good properties and excellent easy adhesion. The reason why a copolymerized polyester resin containing a branching monomer as a component is effective is that crystallization is unlikely to occur, so that it is difficult to lower the transparency and that the polyester base film can secure the flexibility of the easily adhesive layer. This is considered to be because the adhesiveness with the polymer can be improved.

By including fine particles in the easy-adhesion layer, the coefficient of static friction between the obtained easy-adhesion layer surface and the polyester-based substrate film surface can be maintained while maintaining the total light transmittance for visible light at 90% or more. μs) is 0.50 or less and the coefficient of dynamic friction (μd) is 0.45 or less, it is possible to improve the scratch resistance in a post-process or the like while maintaining the high transparency and easy adhesion as described above. it can.

At this time, the fine particles have an average particle diameter of 20 nm.
In the case of containing particles having a particle size of 150 nm or more and particles having an average particle size of 150 nm or more and 1000 nm or less, the friction coefficient can be suitably controlled while maintaining transparency.

On the other hand, according to the production method of the present invention, when the water-soluble polyurethane-based resin is cured, an easy-adhesion layer can be formed together with the copolymerized polyester-based resin. It is possible to stably produce an easily adhesive optical film having easy adhesion by a simple method.

In the above, the aqueous coating solution has an average particle size of 2
0 nm or more and less than 150 nm particles, and an average particle size of 150 n
When the composition contains particles having a size of m or more and 1000 nm or less, scratch resistance in a post-process or the like can be improved while maintaining high transparency and easy adhesion.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in the order of materials used, manufacturing method, and application.

(Materials Used) The easily adhesive film for optical use of the present invention is a film in which an easily adhesive layer is formed on both surfaces of a polyester base film. As the polyester base film, non-stretched films and films that have been subjected to various types of stretching can be used. However, biaxially oriented films are preferable in consideration of transparency, productivity, and the like. Further, both sides are often used in an adhesive state for CRT applications and AR base film applications, and therefore these applications need to be formed on both surfaces.

As the polyester base film, polyethylene terephthalate, polybutylene terephthalate, polyethylene-2,6-naphthalate, or a copolymer containing a polymer component of these resins as a main component is used. Is particularly preferred. When using a copolymer, as the dicarboxylic acid component, adipic acid, aliphatic dicarboxylic acids such as sebacic acid, terephthalic acid, isophthalic acid, phthalic acid,
And aromatic dicarboxylic acids such as 2,6-naphthalenedicarboxylic acid, and polyfunctional carboxylic acids such as trimellitic acid and pyromellitic acid. As the glycol component, ethylene glycol, diethylene glycol, 1,4-
Fatty acid glycols such as butanediol, propylene glycol and neopentyl glycol; aromatic glycols such as p-xylene glycol; alicyclic glycols such as 1,4-cyclohexanedimethanol;
A polyethylene glycol of 0 to 20,000 or the like is used. The proportion of the copolymer component of the preferred copolymer is 20 mol%.
Is less than. If it is at least 20 mol%, the film strength, transparency and heat resistance tend to be poor.

Further, the above-mentioned polyester base film may contain various additives used for the transparent film. As additives, for example, antistatic agents, UV
Absorbers, stabilizers and the like can be mentioned. In addition, it is desirable not to add particles for the purpose of imparting lubricity to the polyester base film. This is because if the easy-adhesion layer to be laminated is provided with a slipperiness by containing fine particles having an appropriate particle size, a good winding property and a function of preventing scratches can be imparted.

The intrinsic viscosity of the resin pellet for the polyester film is preferably in the range of 0.45 to 0.70 dl / g. When the intrinsic viscosity is lower than 0.45 dl / g, the effect of improving tear resistance tends to be deteriorated.
If it is larger than 70 dl / g, the increase in filtration pressure tends to be large, and high-precision filtration tends to be difficult.

As the polyester base film in the present invention, a film having a film thickness of 100 μm or more is preferable, but a film having a thickness corresponding to various uses can be appropriately used.

The easy-adhesion layer in the present invention contains, as main resin components, a copolymerized polyester resin containing a branching monomer as a constituent and a polyurethane resin. When the copolymerized polyester resin alone is used, the adhesion to the polyester base film is sufficient, but the adhesion to the acrylic resin used for the prism lens or the hard coat is poor. Further, the polyurethane resin alone has excellent adhesiveness to an acrylic resin or the like, but is inferior in adhesiveness to a polyester base film.

A copolymerized polyester resin containing a branched monomer as a constituent component can be easily obtained by copolymerization using a branched glycol component. Examples of the branched glycol component include 2,2-dimethyl-1,
3-propanediol, 2-methyl-2-ethyl-1,
3-propanediol, 2-methyl-2-butyl-1,
3-propanediol, 2-methyl-2-propyl-
1,3-propanediol, 2-methyl-2-isopropyl-1,3-propanediol, 2-methyl-2-n
-Hexyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol, 2-ethyl-2-n
-Butyl-1,3-propanediol, 2-ethyl-2
-N-hexyl-1,3-propanediol, 2,2-
Di-n-butyl-1,3-propanediol, 2-n-
Butyl-2-propyl-1,3-propanediol, and 2,2-di-n-hexyl-1,3-propanediol.

The above-mentioned branched glycol component is contained in the total glycol component in a ratio of preferably at least 10 mol%, more preferably at a ratio of 20 to 80 mol%. If it is less than 10 mol%, the adhesiveness to the polyester base film tends to be poor.

As the glycol component other than the above compounds, ethylene glycol is most preferred. If the amount is small, diethylene glycol, propylene glycol, butanediol, hexanediol, 1,4-cyclohexanedimethanol, or the like may be used.

As the dicarboxylic acid component used as a component of the copolymerized polyester resin, terephthalic acid and isophthalic acid are most preferred. If it is a small amount, another dicarboxylic acid; an aromatic dicarboxylic acid of diphenylcarboxylic acid and 2,6-naltalenedicarboxylic acid may be added and copolymerized. It is also possible to use a branched or linear aliphatic dicarboxylic acid, or a salt or lower alkyl ester of the above dicarboxylic acid.

In addition to the above dicarboxylic acid component, it is preferable to use 5-sulfoisophthalic acid or a salt thereof in an amount of 1 to 10 mol% in order to impart water dispersibility. Examples thereof include isophthalic acid, 4-sulfonaphthaleneisophthalic acid-2,7-dicarboxylic acid and 5- (4-sulfophenoxy) isophthalic acid and salts thereof.

As the above monomer component, a trihydric or higher polyhydric alcohol or polyhydric carboxylic acid can be used in addition to a bifunctional one as long as the amount is a small amount.

Examples of the polyurethane resin used in the present invention include various polyurethanes used as various types of solvent type, non-solvent type, or aqueous coating agents. Here, various types of coating agents may be used, such as a two-pack type, a one-pack type, or a block type or non-block type having an isocyanate group.
However, in the present invention, a heat-reactive water-soluble urethane which is a resin containing a block type isocyanate group and in which the terminal isocyanate group of the urethane prepolymer is blocked with a hydrophilic group (hereinafter referred to as a block) is used. preferable.

Examples of the isocyanate group blocking agent include phenols, alcohols, lactams, oximes, and active methylene compounds containing bisulfites and sulfonic acid groups. The blocked isocyanate group renders the urethane prepolymer hydrophilic or water-soluble. When thermal energy is given to the resin during the drying or heat setting process during film production, the blocking agent separates from the isocyanate group, so that the resin fixes the water-dispersible copolymerized polyester resin mixed with the self-crosslinked stitches. And also reacts with the terminal groups of the resin. The resin in the preparation of the coating liquid is poor in water resistance because it is hydrophilic, but when the thermal reaction is completed by coating, drying and heat setting, the hydrophilic group of the urethane resin, that is, the blocking agent comes off, and the water resistance is good. A coating is obtained.

Of the above blocking agents, those which are suitable for heat treatment temperature and heat treatment time and are widely used industrially include:
Bisulfites are most preferred.

The chemical composition of the urethane prepolymer is as follows: (1) a polyol having two or more active hydrogen atoms in a molecule, or a polyol having at least two active hydrogen atoms in a molecule having a molecular weight of 200 to 20; 000 compounds, (2) an organic polyisocyanate having two or more isocyanate groups in the molecule, and if necessary (3) a chain extender having at least two active hydrogen atoms in the molecule,
Is a compound having a terminal isocyanate group obtained by reacting

The compound (1) generally known is a compound containing two or more hydroxyl groups, carboxyl groups, amino groups or mercapto groups at the terminal or in the molecule. Particularly preferred compounds are Examples include polyether polyols and polyether ester polyols. As a polyether polyol,
For example, there are compounds obtained by polymerizing alkylene oxides such as ethylene oxide and propylene oxide, styrene oxide and epichlorohydrin, or compounds obtained by performing random polymerization, block polymerization or addition polymerization to a polyhydric alcohol.

As the polyester polyol and the polyetherester polyol, linear or branched compounds are mainly mentioned. Succinic acid, adipic acid,
Polyvalent saturated or unsaturated carboxylic acids such as phthalic acid and maleic anhydride, or the carboxylic anhydrides and the like, ethylene glycol, diethylene glycol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol and It can be obtained by condensing polyhydric saturated and unsaturated alcohols such as trimethylolpropane, polyalkylene ether glycols such as relatively low molecular weight polyethylene glycol and polypropylene glycol, or a mixture of these alcohols. .

Further, as the polyester polyol, polyesters obtained from lactone and hydroxy acid,
Further, as the polyetherester polyol, polyetheresters obtained by adding ethylene oxide or propylene oxide to polyesters produced in advance can also be used.

As the organic polyisocyanate (2), isomers of toluylene diisocyanate, 4,4
Aromatic diisocyanates such as diphenylmethane diisocyanate, aromatic aliphatic diisocyanates such as xylylene diisocyanate, alicyclic diisocyanates such as isophorone diisocyanate and 4,4-dicyclohexylmethane diisocyanate, hexamethylene diisocyanate, and 2,2,4 -Aliphatic diisocyanates such as trimethylhexamethylene diisocyanate, or polyisocyanates in which one or more of these compounds are previously added to trimethylolpropane or the like.

Examples of the chain extender having at least two active hydrogens of the above (3) include ethylene glycol, diethylene glycol, 1,4-butanediol, and 1,6
Glycols such as hexanediol, polyhydric alcohols such as glycerin, trimethylolpropane, and pentaerythritol; diamines such as ethylenediamine, hexamethylenediamine and piperazine; aminoalcohols such as monoethanolamine and diethanolamine; thiodiethylene Thiodiglycols such as glycol, and water.

In order to synthesize the urethane prepolymer, a single-stage or multi-stage isocyanate polyaddition method using the above-mentioned chain extender is usually performed at a temperature of 150 ° C. or less, preferably 70 to 120 ° C., for 5 minutes to several hours. Let react. The ratio of isocyanate groups to active hydrogen atoms can be freely selected as long as it is 1 or more, but it is necessary that free isocyanate groups remain in the obtained urethane prepolymer.

The content of the free isocyanate group may be 10% by weight or less, but is preferably 7% by weight or less in consideration of the stability of the aqueous urethane polymer solution after blocking.

The resulting urethane prepolymer is preferably blocked using bisulfite. The mixture is mixed with an aqueous bisulfite solution, and the reaction is allowed to proceed with good stirring for about 5 minutes to 1 hour. The reaction humidity is preferably set to 60 ° C. or lower. Thereafter, the mixture is diluted with water to an appropriate concentration to obtain a heat-reactive water-soluble urethane composition. When the composition is used, it is adjusted to an appropriate concentration and viscosity.
When heated to about 200 ° C., the bisulfite of the blocking agent is dissociated, and the active isocyanate group is regenerated. Thus, a polyurethane polymer is generated by a polyaddition reaction occurring within or between molecules of the prepolymer, or It has the property of causing addition to other functional groups.

As an example of the resin (B) containing a blocked isocyanate group described above, Elastron (trade name, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) is typically exemplified.
Elastron is obtained by blocking an isocyanate group with sodium bisulfite, and is water-soluble due to the presence of a carbamoyl sulfonate group having strong hydrophilicity at the molecular terminal.

When the coating liquid is prepared by mixing the copolymerized polyester resin (A) and the polyurethane resin (B) used in the present invention, the weight ratio of the resin (A) to the resin (B) is (A) : (B) = 90: 10 to 10:90, more preferably (A) :( B) = 80: 20 to 2
The range is 0:80. If the ratio of the resin (A) to the solid content is less than 10% by weight, the applicability to the base film tends to be insufficient, and the adhesiveness between the surface layer and the film tends to be insufficient. When the ratio of the resin (B) is 1
If the amount is less than 0% by weight, practically applicable adhesiveness tends to be hardly obtained in a UV-curable hard coat.

A catalyst may be added to the aqueous coating solution used in the present invention in order to promote a thermal crosslinking reaction. For example, inorganic materials, salts, organic materials, alkaline materials, acidic materials and metal-containing organic compounds can be used. Various chemical substances are used. In order to adjust the pH of the aqueous solution, an alkaline substance or an acidic substance may be added.

When the above aqueous coating solution is applied to the surface of the substrate film, a known anionic surfactant and a nonionic surfactant are used in order to increase the wettability to the film and uniformly coat the coating solution. The activator can be used in the required amount.

The solvent used for the coating solution may be an alcohol such as ethanol, isopropyl alcohol and benzyl alcohol, in addition to water, until the ratio of the alcohol to the total coating solution becomes less than 50% by weight. 10% by weight
If it is less than the above, an organic solvent other than alcohols may be mixed in a range in which it can be dissolved. However, the total of alcohols and other organic solvents in the coating liquid is less than 50% by weight. When the addition amount of the organic solvent is less than 50% by weight, the drying property is improved at the time of coating and drying, and the effect of improving the appearance of the coating film is obtained as compared with the case where only water is used. If it exceeds 50% by weight, the solvent evaporates at a high rate, the concentration of the coating solution changes during coating, the viscosity increases, and the coating property decreases, which may cause poor appearance of the coating film. In addition, there is a risk of fire.

In the present invention, in order to make the total light transmittance 90% or more, it is desirable that the base film does not contain particles for imparting lubricity. It is desirable to include appropriate particles for improving the scratching property and the film winding property.

Examples of such particles include inorganic particles such as calcium carbonate, calcium phosphate, silica, kaolin, talc, titanium dioxide, alumina, barium sulfate, calcium fluoride, lithium fluoride, zeolite, and molybdenum sulfide, and crosslinked polymer particles. And organic particles such as calcium oxalate. Among them, silica is most preferable because it has a relatively close refractive index with the polyester resin and easily obtains high transparency.

In the present invention, the easily adhesive layer preferably contains two types of particles (particle A and particle B). The average particle size of the particles A is 20 or more and less than 150 nm, and more preferably 30 to 100 nm. Particle A has an average particle size of 20 n
If it is less than m, both the coefficient of static friction and the coefficient of dynamic friction increase,
It is not preferable because the scratch resistance is poor. Also 150n
It is not preferable to use only particles having a particle size of m or more because the total light transmittance is reduced.

In the present invention, it is preferable to add the particles B in order to further improve the scratch resistance, which is insufficient with the particles A alone. The average particle size of the particles B is 150 to 1000 nm
And more preferably 200 to 600 nm. If the average particle size of the particles B exceeds 1000 nm, the total light transmittance is undesirably low.

The coating amount of the easy-adhesion layer is 0.05 to 0.5.
5 g / m ² is preferred. 0.05 g / m hardly sufficient adhesion can be obtained is less than ^2, it exceeds 0.5 g / m ² and a total light transmittance tends to decrease.

The addition amounts of the particles A and B are appropriately selected, and the static friction coefficient (μs) is 0.50 or less, and the dynamic friction coefficient is 0.5.
By setting the coating amount to 45 (μd) or less and the coating amount within the above range, both transparency and scratch resistance can be achieved. Specifically, the content of the particles A is preferably 5 to 50% by weight, more preferably 10 to 40% by weight in the easily adhesive layer.
Is more preferred. Further, the content of the particles B is preferably 0.1 to 15% by weight in the easily adhesive layer, and 0.2 to 12% by weight.
Is more preferred.

As the coating liquid for forming the easily adhesive layer in the present invention, an aqueous coating liquid is preferably used. Various additives such as an antistatic agent, a UV absorber plasticizer, a pigment, an organic filler, and a lubricant may be mixed with the composition of the aqueous coating solution as long as the effect is not lost. Further, since the coating solution is aqueous, as long as the contribution effect is not lost, in order to improve the performance, other water-soluble resin,
A water-dispersible resin and an emulsion may be added to the coating solution.

(Production Method) In the production method of the present invention, a copolymerized polyester resin containing a branched monomer and a water-soluble polyurethane resin having a block type isocyanate group are provided on the surface of a polyester base film. The method has a step of forming an easy-adhesion layer by applying the contained aqueous coating liquid and then curing it by heating. In addition,
The optical adhesive film of the present invention can be suitably manufactured by the method, but is not limited to this manufacturing method.

In preparing the aqueous coating solution, first, a copolymerized polyester resin containing a branched monomer as a component is modified (introduction of a hydrophilic group) to give water dispersibility, and water and butyl cellosolve are added. By diluting with a mixed solvent or the like, an aqueous dispersion is obtained. An aqueous solution of a blocked self-crosslinking polyurethane resin containing an isocyanate group was mixed with the mixture, and a catalyst for crosslinking reaction, water and a solvent, a surfactant, particles A and B were added as necessary, and a coating solution was added. Is prepared. The materials used are as described above.

The application of the aqueous coating solution is usually performed on the surface of the polyester base film by various coating methods such as a reverse roll method and a doctor blade method. The curing reaction is usually performed by heating to about 80 to 200 ° C., and is performed simultaneously with or after drying.

The optically-adhesive film produced as described above preferably has a total light transmittance for visible light of 90% or more. If the total light transmittance is less than 90%, the film may be used as a base film for AR film or CT.
When used for a crush prevention film for R and the like, the sharpness of the screen tends to decrease.

When the photocurable acrylic coating layer is provided on the easy-adhesion layer of the easy-adhesion film for optical use, the adhesion is 9%.
It is preferably at least 5%. Such adhesiveness can be exhibited by the above-mentioned easily adhesive layer.

(Use) The optically-adhesive film of the present invention can be used as a transparent film layer of various optical members. Specific examples of the optical member include an AR film and a CRT, for example. At that time, the optically-adhesive film is used as a base film for an AR film and as a crush prevention film for a CRT.

The optical adhesive film to be used must have an adhesive layer formed on both sides. This is the case with a base film for an AR film or a crush prevention film for a CTR. This is because adhesion to the layer is required, and the opposite surface is often coated with an adhesive for bonding to another member. Since the easy-adhesion layer in the present invention exhibits excellent adhesiveness to many adhesives, it is also useful for applications using an adhesive as described above.

[0064]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments and the like specifically showing the configuration and effects of the present invention will be described below. The methods for evaluating physical properties and the like in the respective Examples and the like are as follows, and “parts” and “%” indicate “parts by weight” and “% by weight” unless otherwise specified.

(1) Adhesion of Photocurable Acrylic Coating Layer A hard coating agent (Seika Beam EXF01 (B), manufactured by Dainichi Seika Co., Ltd.) was applied to the surfaces of the films obtained in Examples and Comparative Examples using a wire bar. After drying at 70 ° C. for 1 minute to remove the solvent, a thickness of 3 μm was obtained using a high-pressure mercury lamp under the conditions of 200 mJ / cm ² , irradiation distance of 15 cm and running speed of 5 m / min.
m of the hard coat layer was formed.

The adhesiveness of the obtained film was determined by a test method according to JIS-K5400, 8.5.1. Specifically, it penetrates the easy-adhesion layer and reaches the base film 1
After applying 00 cell-shaped cuts using a cutter guide with a gap of 2 mm, a cellophane adhesive tape (405 # 24 mm width, made by Nichiban) was stuck to the cell-shaped cuts and rubbed with an eraser to completely adhere the cuts. The film was peeled off vertically and the adhesion was visually determined from the following formula.

Adhesion (%) = (1-peeling area / evaluation area) × 100 (2) Measurement of total light transmittance Haze meter (Model TC-H3, manufactured by Tokyo Denshoku Industries Co., Ltd.)
DP), the transmittance for visible light was measured.

(3) Measurement of Coefficient of Friction The adhesive film for optical use was 13 cm long × 7 cm wide, and the polyester base film before forming the easy adhesive layer was 10 cm long.
A sample was prepared by cutting into a size of mx 20 cm in width. The surface of the easy-adhesion layer of both samples and the surface of the polyester-based base film are overlapped and the Toyo BALDWIN TENSILON RTM
Using -100, a static friction coefficient (μs) and a dynamic friction coefficient (μd) were obtained at a load of 1.5 kg / 7 × 10 cm and a pulling speed of 200 mm / min.

(4) Scratch resistance An optically easy-to-adhesive film slit to a width of 1000 mm was measured for a diameter of 220 m using a film running tester.
The roller was run on a free roll (surface roughness: 100 nm in terms of Ra) of a hard chrome plating treatment having a rotation resistance of 1 kg and a rotation resistance of 1 kg. The running conditions at this time were a running speed of 10 m / min, a winding angle of 60 °, and a running tension of 10 kg. After this treatment, the scratches in the film were observed with a microscope, and the number of scratches with a width of 3 μm or more and a length of 500 μm or more was less than 10 per m ² , which was excellent; It was determined. Although excellent is desirable, even good is practically usable.

(5) Average Particle Size At least 100 or more particles were observed and photographed with a scanning electron microscope (S-3500N, manufactured by Hitachi, Ltd.), and the resulting image was taken by an image analyzer (Luzex 2 manufactured by Nicole, Inc.).
The Feret diameter was determined using D), and the average value was defined as the average particle diameter.

Example 1 (1) Preparation of Coating Solution A coating solution used in the present invention was prepared according to the following method.
95 parts of dimethyl terephthalate, 95 parts of dimethyl isophthalate, 35 parts of ethylene glycol, 145 parts of neopentyl glycol, 0.1 part of zinc acetate and 0.1 part of antimony trioxide are charged into a reaction vessel, and the ester is added at 180 ° C. for 3 hours. An exchange reaction was performed.

Next, 6.0 parts of 5-sodium sulfoisophthalic acid was added, and the esterification reaction was carried out at 240 ° C. for 1 hour, and then reduced pressure (10 to 0.2 mm) at 250 ° C.
Hg) for 2 hours to carry out a polycondensation reaction, and a molecular weight of 195
00, a polyester resin (A) having a softening point of 60 ° C. was obtained.

30% of the obtained polyester resin (A)
6.7 parts of an aqueous dispersion, 40 parts of a 20% aqueous solution of a self-crosslinkable polyurethane resin (B) containing isocyanate groups blocked with sodium bisulfite (product name: Elastron H-3, manufactured by Daiichi Kogyo Seiyaku), 0.5 parts of a catalyst for Elastron (Cat64 manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), 47.8 parts of water and 5 parts of isopropyl alcohol were mixed, respectively.
Further, 1% by weight of an anionic surfactant, spherical monodispersed silica particles A (manufactured by Nissan Chemical Industries, Ltd .: Snowtex OL,
2 parts of a 20% aqueous dispersion having an average particle diameter of 40 nm was prepared by dry method silica particles B (manufactured by Nippon Aerosil Co., Ltd .; Aerosil OX5).
0, 4% of average particle diameter 200 nm, primary particle diameter 40 nm)
An aqueous dispersion was added in an amount of 0.5 part to prepare a coating liquid.

(2) Pellets containing no particles of polyethylene terephthalate resin having an intrinsic viscosity of 0.62 dl / g as a raw material
After drying under reduced pressure (1 Torr) at 5 ° C. for 6 hours, it is supplied to an extruder and melted and extruded into a sheet at about 280 ° C.
It was quenched and solidified on a metal roll maintained at a surface temperature of 20 ° C. to obtain a cast film having a thickness of 1400 μm.

Next, this cast film was heated to 100 ° C. by a heated roll group and an infrared heater, and then stretched 3.5 times in the longitudinal direction by a roll group having a peripheral speed difference to obtain a uniaxially oriented PET film. .

Thereafter, the coating solution was finely filtered through a felt-type polypropylene filter medium having a filtration particle size (initial filtration efficiency: 95%) of 25 μm, applied on both sides by a reverse roll method, and dried. The coating amount at this time was 0.1 g / m ² . Subsequently, after coating, the end of the film is gripped with a clip and guided to a hot air zone heated to 130 ° C., and a curing reaction is performed while drying. Then, the film is stretched 4.0 times in the width direction, and the thickness is increased. A 100 μm film was obtained.

At this time, the coefficient of static friction (μs) was 0.45,
The dynamic friction coefficient (μd) was 0.40. Table 1 shows the results.

Example 2 In the preparation of the coating solution, the particles A
1 part of a 20% aqueous dispersion, and 0.1 part of a 4% aqueous dispersion of particles B.
An easy-to-use optical adhesive film was obtained in the same manner as in Example 1 except that 3 parts were used. The static friction coefficient (μs) at this time is 0.4
8. The dynamic friction coefficient (μd) was 0.44. Table 1 shows the results.

Example 3 In the preparation of the coating solution, the particles A
Was obtained in the same manner as in Example 1 except that 4 parts of a 20% aqueous dispersion of the above was used and 1 part of a 4% aqueous dispersion of the particles B was 1 part.

At this time, the coefficient of static friction (μs) was 0.43,
The dynamic friction coefficient (μd) was 0.40. Table 1 shows the results.

(Comparative Example 1) An easily adhesive optical film was obtained in the same manner as in Example 1 except that the polyester resin (A) was not added in the preparation of the coating solution.

At this time, the coefficient of static friction (μs) was 0.45,
The dynamic friction coefficient (μd) was 0.41. Table 1 shows the results.

(Comparative Example 2) An easily adhesive film for optical was obtained in the same manner as in Example 1 except that the urethane resin (B) was not added in the preparation of the coating solution.

The coefficient of static friction (μs) at this time was 0.45,
The dynamic friction coefficient (μd) was 0.43. Table 1 shows the results.

Reference Example 1 Particles A were used in the preparation of the coating solution.
Average particle diameter of 1400 nm (310
An easily adhesive film for optical use was obtained in the same manner as in Example 1 except that the particles of No. 1) were used.

The coefficient of static friction (μs) at this time was 0.31,
The dynamic friction coefficient (μd) was 0.28. Table 1 shows the results.

(Reference Example 2) In preparing a coating solution, particles A
Was obtained in the same manner as in Example 1 except that was not added.

At this time, the coefficient of static friction (μs) was 0.61, and the coefficient of dynamic friction (μd) was 0.58. Table 1 shows the results.

[0089]

[Table 1] As shown in the results of Table 1, the optical adhesive films of Examples 1 to 3 were all excellent in the total light transmittance, the adhesive property, and the scratch resistance. On the other hand, in Comparative Examples 1 and 2, in which the polyester resin (A) or the urethane resin (B) was not contained in the easy-adhesion layer, the easy-adhesion property was considerably low. In addition, Reference Examples 1 to 1 in which the blending of fine particles is not appropriate
In No. 2, the deterioration of the total light transmittance and the deterioration of the easy adhesion due to the increase of the static friction coefficient and the dynamic friction coefficient occurred.

 ──────────────────────────────────────────────────続 き Continuing on the front page F term (reference) 2K009 AA15 BB24 CC09 CC34 CC35 DD01 DD06 EE00 4F100 AA20 AK41A AK41B AK41C AK51B AK51C AL01B AL01C AL05B AL05C BA03 BA06 BA10B BA10C CA19B CA19C J23B CA01BJ01B23C23C JL11B JL11C JN01B JN01C YY00B YY00C

Claims (5)

[Claims] 1. An easy-to-use optical adhesive film in which an easy-adhesion layer is formed on both sides of a polyester-based base film, wherein the easy-adhesion layer is a copolymerized polyester containing a branched monomer as a main resin component. An easy-to-use optical adhesive film comprising a resin and a polyurethane resin. 2. The static friction between the surface of the obtained easy-adhesion layer and the surface of the polyester-based base film while maintaining the total light transmittance for visible light at 90% or more by incorporating fine particles into the easy-adhesion layer. The optical adhesive film according to claim 1, wherein the coefficient (μs) is 0.50 or less and the dynamic friction coefficient (μd) is 0.45 or less. 3. The fine particles have an average particle size of 20 nm or more.
Particles having a particle size of less than 50 nm and an average particle size of 150 nm or more and 100
The easy-to-use optical adhesive film according to claim 2, comprising particles of 0 nm or less. 4. The method according to claim 1, wherein the surface of the polyester base film is
After applying an aqueous coating solution containing a copolymerized polyester-based resin having a branching monomer as a component and a water-soluble polyurethane-based resin having a block-type isocyanate group, curing by heating to form an easy-adhesion layer. A method for producing an easy-to-use optical adhesive film. 5. An aqueous coating liquid comprising: particles having an average particle diameter of 20 nm or more and less than 150 nm;
The production method according to claim 4, further comprising particles having a size of 000 nm or less.