KR20110080414A - Readily bondable polymer substrate and film for optical use using the same - Google Patents

Abstract

PURPOSE: A polymer substrate is provided to ensure excellent optical characteristics and easy adhesion to the post processing layer in the post processing of a prism processing layer, lens processing layer, anti-reflective layer, and hardcoating layer. CONSTITUTION: A polymer substrate has a structure where a primer layer formed with a primer layer solution is laminated on one side of a polyester-based base material film layer, wherein acryl-, polyurethane- or polyester-based resins are included in two kinds or more of water-dispersible mixed solvents. The adhesive property to a substrate film layer is improved by microphase separation. The water-dispersible mixed solvent is such that water having a boiling point of 100°C and glycol solvents having a boiling point of 150~250°C are mixed.

Description

Easily-adhesive polymer substrate and optical film member using the same {READILY BONDABLE POLYMER SUBSTRATE AND FILM FOR OPTICAL USE USING THE SAME}

The present invention relates to an easily-adhesive polymer substrate and an optical film member using the same. More particularly, the surface roughness of the coating layer is induced by inducing microphase separation on a polymer substrate having a structure in which a primer layer is laminated on a polyester base film layer. The present invention relates to a polymer substrate and an optical film member using the polymer substrate having improved adhesion to the substrate film layer.

In general, polyester film is excellent in dimensional stability, thickness uniformity and optical transparency is a material that is widely used as a display material as well as various industrial materials.

As a representative example, a functional polyester base film in which a primer layer using a homogeneous copolyester-based binder resin is laminated on a polyester base material is widely used.

However, since the primer layer made of the copolyester-based binder resin is the same material as that of the polyester-based base material, the adhesive layer is excellent in adhesiveness, but heat resistance, moisture resistance, adhesion strength, and the like are reduced. In addition, in the post-processing of the prism processing layer, the lens processing layer, the antireflection layer, the hard coating layer, etc. to which the base material of another material is applied, the easily adhesive property is significantly reduced.

Recently, in order to improve heat and moisture resistance, which are the above problems, and to improve various UV curing resins and adhesive strengths used in post-processing, acrylic or polyurethane-based binder resins are additionally introduced, and the refractive index is improved. As a result of increasing the excellent performance in terms of brightness, there is increasing interest in the development of acrylic or polyurethane-based binders.

However, in the case of the acrylic or polyurethane-based binder, even if it has a property of excellent heat resistance and easy adhesion with UV curable resin during post-processing, the adhesiveness with various polyester-based substrates, which are substrate layers, is insufficient at the time of adhesion test. The problem that the primer layer consisting of the acrylic or polyurethane-based binder resin is separated from the ester base layer has been pointed out.

An object of the present invention is to provide an optical polymer substrate having improved adhesiveness by microphase separation of the primer layer as a polymer substrate having a primer layer laminated on a polyester base film layer.

Another object of the present invention is to provide a use of the polymer substrate applicable to the optical film member.

In order to achieve the above object, the present invention is a polyester-based base film layer; And a primer layer comprising at least one surface of the base film layer, a primer layer solution containing an acrylic, polyurethane, or polyester resin in two or more aqueous dispersion-based mixed solvents, wherein the two or more aqueous dispersions are mixed. Provided is a polymer substrate having improved adhesion to a base film layer by interlayer microphase separation due to a solvent.

In the above, the two or more types of water-based mixed solvents are a mixture of a glycol solvent having a boiling point of 100 ° C. water and a boiling point of 150 to 250 ° C., and the glycol solvents include ethylene glycol, diethylene glycol, and the like. It is at least one selected from the group consisting of dimethylene glycol dimethyl ether. At this time, it is preferable that 1-20 weight% of glycol solvents are contained with respect to the total water-based mixed solvent.

In the polymer substrate of the present invention, the thickness of the primer layer is preferably 0.01 to 5.00 µm.

In the polymer base material of the present invention, the primer layer production solution is 10 to 25% by weight of acrylic binder resin or polyurethane binder resin, 10 to 20% by weight of copolyester resin, melamine or epoxy curing agent 1.0 to 10% by weight of solid content %, Nonionic surfactant 1.0 to 10% by weight, 0.1 to 5% by weight of silica nanoparticles with an average particle diameter of 10 to 300 nm, and the remaining amount of 2 or more types of water dispersion mixtures excluding the composition content from the total composition content of 100% by weight It consists of a solvent.

In the polymer substrate of the present invention, the total light transmittance of the surface of the base film layer on which the primer layer is formed has an optical characteristic of 85% or more and a haze value of 0.3 to 2%.

In addition, the adhesion between the base film layer and the primer layer is maintained at 95 to 100% after a 96 hours moisture resistance test under 65 ℃ temperature and 95% humidity conditions.

In the polymer substrate of the present invention, the surface roughness between the primer layer and the substrate film layer is 2 to 10 μm, and the high adhesion to the substrate layer is improved by the microphase separation of the primer layer during high temperature drying.

Furthermore, the polymer base material of the present invention has excellent adhesion between the base film layer and the primer layer, and at high temperature drying, microphase separation is induced by two or more water-dispersive mixed solvents contained in the primer layer, thereby improving easy adhesion. .

Accordingly, the present invention is an optical for the polymer substrate is applied to any one selected from the group consisting of a prism sheet base film for LCD, a base film for backlight, a base film for hard coating processing, a base film for antireflection film and a protective film for CRT Provided for use as a film member.

According to the present invention, in a polymer substrate having a structure in which a primer layer is laminated on a polyester base film layer, two or more kinds of water-based mixed solvents having different boiling points in the primer layer manufacturing solution are contained, and when boiling at high temperature, the boiling point Since relatively low water evaporates first to induce fine phase separation, the surface roughness of the coating layer is increased to provide a polymer substrate having improved adhesion to the base film layer.

The polymer substrate of the present invention has excellent optical properties, and easily adheres to the post-processing layer during post-processing such as a prism processing layer, a lens processing layer, an antireflection layer, and a hard coating layer to which a polyester base film and other materials are applied. Since it is improved, it can be utilized as an optical film member using the same.

1 is a surface photograph of a polymer substrate induced microphase separation of the present invention,
Figure 2 is a surface photograph of a conventional polymer substrate is not induced microphase separation.

Hereinafter, the present invention will be described in more detail.

The present invention on at least one surface of the polyester base film layer,

A primer layer composed of a primer layer manufacturing solution containing acrylic, polyurethane, or polyester resin is laminated on at least two aqueous dispersion solvents, and the base film is separated by microphase separation due to the two or more aqueous dispersion solvents. Provided is a polymeric substrate with improved adhesion to a layer.

In the case of a general polymer substrate, the primer layer laminated on the base film layer is laminated using an acrylic or polyurethane binder resin and a copolyester resin, and due to the surface tension between the materials constituting the base film layer and the primer layer, While the upper and lower structures of the different, the adhesiveness between the base film layer and the primer layer can be improved.

Thus, the present invention by forming a primer layer in the primer layer using a different solvent having a boiling point and solubility difference with the solvent with an aqueous solvent, thereby maximizing the microphase separation due to the solvent to the difference between the base film layer It is characterized by improving the adhesion.

In the polymer substrate of the present invention, the primer layer may be formed by applying a primer layer preparation solution containing acrylic, polyurethane, or polyester resin to two or more aqueous dispersion-based mixed solvents on a base film layer.

More specifically, the primer layer preparation solution is 10 to 25% by weight of acrylic binder resin or polyurethane-based binder resin, 10 to 20% by weight of copolyester resin, melamine or the like in two or more aqueous dispersion-based mixed solvents It contains 1.0-10 weight% of epoxy-type hardening | curing agents, 1.0-10 weight% of nonionic surfactants, and 0.1-5 weight% of silica nanoparticles with an average particle diameter of 10-300 nm.

In the polymer substrate with improved adhesiveness of the present invention, the water-based mixed solvent which serves to induce the microphase separation of the primer layer is boiling point 100 ℃ water; And a solvent having a higher boiling point than that of the water. As a result, when the polymer substrate of the present invention is dried at a high temperature, water having a relatively low boiling point is evaporated first to induce fine phase separation of the coating layer, thereby improving surface roughness, thereby improving the adhesiveness during post-processing.

At this time, as a solvent having a higher boiling point than water, it is preferable to add a glycol solvent having a boiling point of 150 to 250 ° C, and more preferably 180 to 210 ° C. As a preferable example of the glycol solvent, at least one selected from the group consisting of ethylene glycol, diethylene glycol, and dimethylene glycol dimethyl ether is used.

At this time, it is preferable that 1-20 weight% of glycol solvents are contained with respect to the total water dispersion type mixed solvent of this invention, More preferably, it contains 5-15 weight%. When the content of the glycol solvent is less than 1% by weight, the microphase separation effect of the primer layer is insignificant, so that it is difficult to expect the improvement of the adhesion and the moisture resistance adhesion strength. When the content of the solvent exceeds 20% by weight, the primer layer is not sufficiently coated on the base film layer. This results in poor coating properties and rather low interlayer adhesion.

In the polymer base material of the present invention, the primer layer is formed by applying a primer layer preparation solution on the base film after the polyester base film is uniaxially stretched. At this time, the thickness of the primer layer is preferably 0.01 to 5.00 µm, more preferably 0.05 to 3.00 µm. If the coating thickness of the primer layer is thinner than 0.01㎛, the transparency is good but the adhesive strength during post-processing, when thicker than 5㎛ is excellent in adhesive properties, but the transparency and coating property is not preferred because it is reduced.

In the composition of the primer layer preparation solution of the present invention, the surfactant is used to increase the wettability of the polyester base film layer and to uniformly apply the coating solution to enable the application of a water-soluble coating solution, and a known anionic or nonionic surfactant may be used. Can be.

In addition, a curing agent such as melamine or epoxy is used for the purpose of improving durability, and may be selected from known compound groups.

In addition, the primer layer solution of the present invention may be used in the coating solution to improve the coating properties and functionality, such additives may be used organic particles, inorganic particles, antifoaming agents, etc. According to the present invention, the water-soluble polymer Running property can be ensured by containing an inorganic particle with a comparatively small difference in refractive index with resin in a primer layer. However, when the average particle diameter of the particles exceeds 300 nm, a problem occurs that affects the haze, and thus the size of the silica inorganic particles used in the present invention has a particle size in the range of 10 to 300 nm.

In the polymer substrate of the present invention, the optical ray transmittance of the surface of the base film layer on which the primer layer is formed is 85% or more, and the haze value is 0.3 to 2%, more preferably 0.4 to 1.5%.

In addition, it can be confirmed that the adhesion between the base film layer and the primer layer is maintained at 95 to 100% even after 96 hours humidity resistance test at 65 ℃ temperature and 95% humidity conditions [ Table 1 ].

In addition, the polymer substrate of the present invention is confirmed that the microphase separation is induced by two or more types of water-based mixed solvent contained in the primer layer, the surface roughness between the primer layer and the base film layer is increased to 2 to 10㎛ at high temperature drying Can be.

1 is a photograph observing the surface of the polymer substrate prepared in Example 3 of the present invention, the polymer substrate of Comparative Example 2 prepared without using a solvent having no boiling point of 150 ~ 250 ℃ glycol solvents Compared to FIG. 2 , it can be seen that the surface roughness can be improved, and the adhesion to the base film layer can be improved.

Therefore, the polymer base material of the present invention improves the adhesion between the base film layers while maintaining the excellent optical properties of the polyester material.

In addition, the adhesion between the polyester base film layer and the primer layer which is widely used in the industry is remarkably improved, and the prism processing layer, lens processing layer, anti-reflection layer, hard coating layer to which the polyester base film and other materials are applied. In the post-processing, etc., the (vertical) luminance value is improved compared to the existing one, and at the same time it can be confirmed that the improved adhesion to the post-processing layer.

Therefore, the polymer base material of the present invention can be used throughout the various optical members that maintain excellent adhesion even under high temperature and high humidity conditions.

Furthermore, this invention provides the use as an optical film member using the said polymer base material.

More specifically, the polymer substrate of the present invention may be used as any one selected from the group consisting of a prism sheet substrate film for LCD, a substrate film for backlight, a substrate film for hard coating processing, a substrate film for antireflection film, and a protective film for CRT. .

In the polymer substrate of the present invention, the polyester base film layer may be a material selected from polyethylene terephthalate, polyethylene naphthalate or polycarbonate, wherein the thickness of the polyester base film layer is 50 ~ 300㎛ desirable.

More specifically, the polyester base film layer is made of a copolyester-based resin, and the dicarboxylic acid component and the branched glycol component are prepared from the constituent components.

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-propane Diol, 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 and the like Can be mentioned.

The branched glycol component is preferably contained in the total glycol component at a rate of 10 mol% or more, particularly preferably in a ratio of 20 mol% or more. In addition, it is preferable to contain the said branched glycol component in the ratio of 80 mol% or less in all the glycol components. If it is less than 10 mol%, there exists a tendency for adhesiveness with a biaxially-oriented polyester film to become inadequate.

As glycol components other than the said compound, ethylene glycol is the most preferable, A small amount of diethylene glycol, propylene glycol, butanediol, hexanediol, 1, 4- cyclohexane dimethanol, etc. can also be used.

The dicarboxylic acid component contained as a component in the copolyester-based resin is most preferably terephthalic acid and isophthalic acid, and a small amount of aromatic dicarboxylic acid of diphenylcarboxylic acid and 2,6-naphthalenedicarboxylic acid is added. By copolymerization.

In addition to the dicarboxylic acid component, in order to impart water dispersibility, it is preferable to use 5-sulfoisophthalic acid in the range of 1 to 10 mol%, and for example, sulfoterephthalic acid, 5-sulfoisophthalic acid, 4 -Sulfonnaphthalene isophthalic acid -2,7-dicarboxylic acid, 5- (4-sulfophenoxy) isophthalic acid, its salts, etc. are mentioned.

Hereinafter, the present invention will be described in detail with reference to examples.

The following examples are merely illustrative of the present invention, but the scope of the present invention is not limited to the following examples.

≪ Example 1 >

50.0% by weight of aqueous dispersion containing 30% by weight of copolymerized polyester resin in 70% by weight of water, 50.0% by weight of aqueous dispersion containing 30% by weight of urethane-based binder resin in 70% by weight of water, and 70% by weight of water to improve moisture resistance. 5% by weight of an aqueous dispersion containing 30% by weight of a melamine-based curing agent was added to a mixed solvent of 1% by weight of ethylene glycol and 62.9% by weight of water, and 90% by weight of water contained 10% by weight of anionic surfactant. A coating liquid for preparing a primer layer containing 0.5 wt% of an aqueous dispersion containing 70 wt% of colloidal silica particles in 11 wt% of a dispersion and 30 wt% of water was prepared.

The coating solution was applied to a polyethylene terephthalate (PET) substrate having a thickness of 100 μm.

<Example 2>

Except for mixing 5% by weight of ethylene glycol and 58.9% by weight of water with respect to the mixed solvent composition in Example 1, was carried out in the same manner as in Example 1, to prepare a coating liquid for preparing a primer layer. Thereafter, the coating solution was applied to a polyethylene terephthalate (PET) substrate having a thickness of 100 μm.

<Example 3>

With respect to the mixed solvent composition in Example 1, except for mixing 10% by weight of ethylene glycol and 53.9% by weight of water, was carried out in the same manner as in Example 1, to prepare a coating liquid for preparing a primer layer. Thereafter, the coating solution was applied to a polyethylene terephthalate (PET) substrate having a thickness of 100 μm.

Comparative Example 1

With respect to the mixed solvent composition in Example 1, except for mixing 20% by weight of ethylene glycol and 43.9% by weight of water, was carried out in the same manner as in Example 1, to prepare a coating liquid for preparing a primer layer. Thereafter, the coating solution was applied to a polyethylene terephthalate (PET) substrate having a thickness of 100 μm.

Comparative Example 2

With respect to the mixed solvent composition in Example 1, except that 63.9% by weight of water was used, it was carried out in the same manner as in Example 1, to prepare a coating liquid for preparing a primer layer. Thereafter, the coating solution was applied to a polyethylene terephthalate (PET) substrate having a thickness of 100 μm.

Experimental Example 1

The adhesion between the PET substrate and the primer layer was measured on the polymer substrates prepared in Examples 1 to 3 and Comparative Examples 1 to 2. More specifically, the acrylic UV curable resin is applied to the surface to which the primer layer is attached using a # 20 wire bar, and then a cutting line is made on the film coated with the primer layer by a cutter, and 2 mm in a 10 × 10 matrix. The x 2 mm squares were placed. A cellophane tape (No. 405, manufactured by NICHIBAN; width: 24 mm) was attached to the film with cut lines, and the tape was rubbed strongly using a velvet to adhere to the film. Then remove the tape vertically. The area of the primer layer remaining in the adhesive layer was visually observed, and the adhesiveness was calculated by the following equation.

In addition, the adhesion test for the evaluation of moisture resistance after 96 hours at 65 ℃ temperature and 90% humidity conditions was also performed in the same manner as above.

Experimental Example 2

In Examples 1 to 3 and Comparative Examples 1 to 2, the coating property between the coating solution, which is a primer layer, and the substrate were measured. More specifically, the primer layer was applied to the substrate using # 0 to # 4 wire bars to confirm whether the primer layer was coated on the entire surface of the substrate. Visually, it was evaluated that coating property was excellent when there were less than two parts without coating liquid as in Ireland.

Experimental Example 3

After curing by applying to the 188nm PET substrate with the coating solution prepared above, the haze and transmittance were measured using a haze meter [NIPPON DENSHOKU].

Experimental Example 4

After the thermosetting by applying the coating liquid prepared above to the 188nm PET substrate, using a three-dimensional surface formation measuring instrument [WYKO, NT1100 OPTICAL PROFILING SYSTEM manufactured by VEECO,] centerline average roughness (Ra) and 10 points Average roughness (Rz) was measured.

Experimental Example 5

The physical property measurement results for the polymer substrates according to Experimental Examples 1 to 3 and Comparative Examples 1 to 2 are shown in Table 1 below.

From the results of Table 1 above, when preparing a primer layer laminated on the polyester base layer, when the glycol solvent having a high solubility and boiling point similar to the high temperature drying conditions in the manufacturing process, the base layer and the primer layer Confirmed excellent coating properties and adhesion. On the other hand, compared to Comparative Example 2 without the addition of the glycol solvent [Fig. 2], in the case of the example in which the glycol solvent is added, the surface roughness was found to increase in proportion to the content of the glycol solvent [ 1].

Therefore, the polymer substrate of the present invention can improve the adhesion between the substrate layers by increasing the surface roughness by inducing a microphase separation effect on the surface by the first evaporation of water contained in the primer layer during high temperature drying. have.

In addition, the polymer base material of the present invention has excellent brightness synergistic effect during post-processing such as prism lens processing, hard coating processing, anti-reflection (AR) processing, diffusion, etc., and improves easily adhesiveness with the post-processing layer. It can be utilized as a film member.

As described above,

The polymer substrate of the present invention has a structure consisting of a primer layer laminated on a polyester base film layer, and when the primer layer is prepared, two or more water-based mixed solvents are used, and the surface of the polymer layer is first vaporized by water. By inducing a microphase separation effect on the phase, as the surface roughness is increased, the adhesion between the substrate layers was improved. Thus, the problem of the conventional polymer substrate is solved by improving the adhesiveness with the base film while maintaining the excellent optical characteristics of the polyester base film.

In addition, the polymer substrate of the present invention, since the adhesion between the post-processing layer during the post-processing of the prism processing layer, lens processing layer, anti-reflection layer, hard coating layer, etc. to which the polyester base film and other materials are applied, the prism for LCD It can be used as an optical film member, such as a sheet base film, a backlight base film, a hard coating base film, an antireflection film base film, a CRT protective film.

Although the present invention has been described in detail only with respect to the embodiments described, it will be apparent to those skilled in the art that various modifications and variations are possible within the technical scope of the present invention, and such modifications and modifications belong to the appended claims.

Claims (10)

On at least one surface of the polyester base film layer,
It is a structure in which a primer layer made of a primer layer manufacturing solution containing acrylic, polyurethane, or polyester resin is laminated on two or more water-based mixed solvents, and the base film is separated by microphase separation by the two or more water-based mixed solvents. Polymer substrate with improved adhesion to the layer. The polymer base material according to claim 1, wherein the two or more types of water-based mixed solvents have a boiling point of 100 ° C and a glycol solvent having a boiling point of 150 to 250 ° C. The polymer base material according to claim 1, wherein the glycol solvent is contained in an amount of 1 to 20% by weight based on the total aqueous dispersion mixed solvent. The polymer base material according to claim 1, wherein the glycol solvent is at least one selected from the group consisting of ethylene glycol, diethylene glycol, and dimethylene glycol dimethyl ether. The polymer base material according to claim 1, wherein the primer layer has a thickness of 0.01 to 5.00 mu m. The method of claim 1, wherein the primer layer manufacturing solution compared to the solid content,
10-25 wt% of acrylic binder resin or polyurethane binder resin,
10 to 20% by weight of copolyester resin,
1.0-10% by weight of melamine or epoxy curing agent,
1.0-10% by weight of non-anionic surfactant,
0.1 to 5% by weight of silica nanoparticles with an average particle diameter of 10 to 300 nm and
The polymer substrate, characterized in that contained in at least two kinds of water-dispersible mixed solvent of the remaining amount excluding the composition content in the total composition content 100% by weight. The polymer substrate according to claim 1, wherein the polymer substrate has optical properties of a total light transmittance of 85% or more and a haze value of 0.3 to 2% or less of the surface of the base film layer on which the primer layer is formed. The method according to claim 1, wherein the adhesion between the base film layer and the primer layer is calculated by Equation 1 below, and the adhesion is 95 to 100% after a 96 hour moisture resistance test under a temperature of 65 ° C. and 95% humidity. The polymer substrate, characterized in that.
Equation 1

The polymer substrate of claim 1, wherein a surface roughness of the primer layer and the base film layer is 2 to 10 μm by the microphase separation of the primer layer during the high temperature drying. The polymer substrate according to any one of claims 1 to 9
An optical film member applied to any one selected from the group consisting of a prism sheet base film for LCD, a base film for backlight, a base film for hard coating processing, a base film for antireflection film, and a protective film for CRT.

Images