KR101500124B1 - Highly stable solution for coating compositions and method for manufacturing the same, polyester film using the same - Google Patents

Abstract

A coating composition excellent in solution stability which not only provides sufficient adhesion and transparency with an optical film laminated on a base film but also has a slip property and is capable of preventing blocking phenomenon during winding and having an excellent film surface appearance . The present invention relates to a coating composition for forming a coating layer on one side or both sides of a polyester base film, which comprises 1 to 40% by weight of a polyacrylic resin; 0.25 to 15% by weight of a hardener; 0.1 to 5% by weight of an oxidation catalyst; 0.05 to 5 wt% wetting agent; 0.01 to 10% by weight of inorganic particles; 1 to 20% by weight of an alcoholic organic solvent; And 5 to 97.59% by weight of water, wherein the coating composition has an acidity (pH) of 9 to 11 except for the oxidation catalyst.

Description

TECHNICAL FIELD [0001] The present invention relates to a coating composition for a polyester film excellent in solution stability, a process for producing the same, and a polyester film using the same. BACKGROUND ART [0002]

TECHNICAL FIELD The present invention relates to a coating composition for a polyester film, a method for producing the same, and a polyester film using the same. More specifically, the present invention relates to a coating composition for a polyester film excellent in solution stability and used as a base film of an optical film, And a polyester film using the same.

In general, the polyester film is excellent in mechanical properties, dimensional stability, chemical resistance and transparency, and is used not only in the fields of magnetic recording media, capacitors, seasonal insulating materials and packaging, but also in recent years in optical applications such as LCDs, LEDs and PDPs And so on.

When such a polyester film is used for optical use, it is used after being processed by a hard coating layer, a prism lens, an antireflection plate, a light diffusion layer, or the like, depending on requirements, A technique of improving the adhesion by coating a primer layer using acryl, ester, urethane resin or the like which imparts the adhesiveness has been developed in order to compensate for the adhesion with such a post-processing material.

Patent Publication No. 0742428 discloses an adhesive polyester film for optical use in which a heat reactive type water-soluble urethane resin, a polyester-based urethane resin or an acrylic copolymer resin is used as a binder and a coating layer containing a nonionic surfactant and inert particles is formed. But it contains a surfactant component and has a problem that it is difficult to roll the product in a roll product due to slipping of the film due to excessive slip property.

Open Patent Publication No. 2005-0051089 discloses a method for producing an antistatic pressure-sensitive adhesive which comprises applying an antistatic pressure-sensitive adhesive composition using a conductive coating composition comprising a conductive polymer, an adhesive binder, a functional additive, an alcohol, water, However, excessive use of alcohol and organic solvent adversely affects the quality and precision of the product, and the production process in which the film is produced is performed under a clean room environmental condition, and air pollution There is a problem in that indoor air cleaning is also out of tolerance.

Open Patent Publication No. 2012-0104492 discloses a laminated polyester film which can be suitably used in applications requiring good adhesion to a hard coat layer or the like, for example, a member constituting a liquid crystal display, and the like, but epoxy, oxazoline , Melamine, and other hardening agents, the content of the curing agent is excessive relative to the resin. Excessive use of the curing agent may cause a problem of deterioration of the adhesion, and as the number of functional groups capable of reacting with the resin increases, There is a problem that is likely to occur.

In the non-patent document (Guillaume Tillet, Bernard Boutevin, Bruno Ameduri, Chemical reactions of the polymer crosslinking and post-crosslinking at room and medium temperature, Progress in Polymer Science, 36 (2011), 191-217) (Melamine) at room temperature, the room temperature stability of the coating solution, such as the generation of foreign materials, may be lowered due to the room temperature reaction between the curing agent and the final product.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a coating composition for forming a coating layer on one side or both sides of a polyester base film used for an optical film to impart the adhesive property to a base film, A coating composition excellent in stability of a solution which can sufficiently exhibit adhesiveness and transparency with the optical film to be laminated, has a favorable slip property and can prevent blocking phenomenon during winding, has excellent film surface appearance, and a poly To provide an ester film and a method for producing an optimized coating composition capable of imparting such properties.

In order to solve the above problems, the present invention provides a coating composition for forming a coating layer on one side or both sides of a polyester base film, comprising: 1 to 40% by weight of a polyacrylic resin; 0.25 to 15% by weight of a hardener; 0.1 to 5% by weight of an oxidation catalyst; 0.05 to 5 wt% wetting agent; 0.01 to 10% by weight of inorganic particles; 1 to 20% by weight of an alcoholic organic solvent; And 49 to 93.85% by weight of water, wherein the coating composition has an acidity (pH) of 9 to 11 except for the oxidation catalyst.

Also, the water dispersion type polymer coating composition has an acidity (pH) of 7 to 8.5.

The polyacrylic resin may be at least one selected from the group consisting of methacrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, ethylhexyl methacrylate, phenyl methacrylate, Acrylate, methacrylate, glycidyl methacrylate, glycidyl methacrylate, ethyleneglycol acrylate, ethylene glycol methyl acrylate, alkylaryl methacrylate, succinic methacrylate, glycidyl methacrylate, Styrene, and butyl acrylate are copolymerized with each other. The present invention also provides an aqueous polymer coating composition comprising the same.

Also, the polyacrylic resin has an average particle size of 10 to 200 nm, and the particles are dispersed in a colloid state using the water as a dispersion medium.

The curing agent may be a water-soluble thermosetting melamine resin, a water-soluble thermosetting melamine formaldehyde resin, an epoxy-based curing resin, a silane coupling agent, an aziridine-based curing agent, an oxazoline-based curing agent, a carbodiimide-based curing agent, and blocked isocyanate. The present invention also provides an aqueous dispersion coating composition comprising the same.

The oxidation catalyst may be at least one selected from the group consisting of a hydrazide compound, a hydrazine compound, a hydroxylamine compound, an imide compound, an imide compound, an imine compound, a cyanate compound, an isocyanate compound, Cyanate-based compound, and a cyanate-based compound.

The wetting agent may be a wetting agent such as a sulfosuccinate wetting agent, an alkyl alcohol wetting agent, an alcohol ethoxylate wetting agent, a fluorine wetting agent, a polysiloxane wetting agent, an acetylene glycol wetting agent, an ethylene glycol wetting agent or an alkylene glycol monoalkyl ether wetting agent Wherein at least one selected from the group consisting of water-dispersible polymer coating compositions and water-dispersible polymer coating compositions is provided.

The inorganic particles may be at least one selected from the group consisting of talc, silica, calcium carbonate, magnesium carbonate, barium carbonate, calcium sulfate, calcium phosphate, magnesium phosphate, kaolin, aluminum oxide, titanium oxide, zirconia, titania, Wherein at least one selected from the group consisting of iron oxide, manganese dioxide, silicon carbide, copper oxide, cobalt oxide, nickel oxide, tin oxide, chromium oxide, zinc oxide and organic clay is provided.

The acidic pH adjusting agent is at least one selected from the group consisting of triethylamine, trimethylamine, methylamine, tetramethylammonium hydroxide, ammonia, potassium hydroxide and aminomethylpropanol. to provide.

In order to solve the other problems, the present invention provides a polyester film having a coating layer formed on one or both sides of a polyester base film, wherein the coating layer is a primer coating layer formed of the coating composition.

According to another aspect of the present invention, there is provided a method for manufacturing a semiconductor device, comprising the steps of: (a) preparing a first mixed solution containing 1 to 20% by weight of an alcoholic organic solvent and 0.25 to 15% (b) preparing a second mixed solution by adding and stirring from 49 to 93.85% by weight of water, 1 to 40% by weight of a polyacrylic resin, 0.05 to 5% by weight of a wetting agent and 0.01 to 10% (c) adding and stirring the first mixed solution and the acidity adjusting agent to the second mixed solution to prepare a water dispersion mixed solution having an acidity (pH) of 9 to 11; And (d) adding 0.1 to 5% by weight of an oxidation catalyst to the aqueous dispersion mixture to prepare an aqueous dispersion mixture having an acidity (pH) of 7 to 8.5.

According to the present invention, a coating composition having an optimum acidity with a water-dispersing and mixing liquid containing an optimal amount of a polyacrylic binder resin, a curing agent, an oxidation catalyst, a wetting agent, an inorganic particle, an alcohol organic solvent and water There is provided a coating composition excellent in adhesion and transparency to a laminated optical film by forming a primer coating layer as well as preventing foreign matter from occurring on the surface of the film and having excellent slipperiness, a method for producing the same, and a polyester film using the same .

Further, by using an oxidation catalyst instead of using a conventional or excessive amount of a curing agent, the reaction between the curing agent is reduced to improve the solution stability of the coating composition, and when using the curing agent, the adhesive property and slipperiness A coating composition, a process for producing the same, and a polyester film using the same.

Hereinafter, preferred embodiments of the present invention will be described in detail. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. Throughout the specification, when an element is referred to as "including " an element, it means that it can include other elements, not excluding other elements, unless specifically stated otherwise.

The present inventors have found that, when forming the adhesive primer coating layer using a coating composition on a polyester film used as an optical base film, when many or excessive amounts of a curing agent are used in the binder resin, agglomeration of the solution occurs due to reaction between the curing agent, Coagulation causes defects in the final product, and also causes problems such as filter clogging and contamination in the coating process, thereby increasing the inconvenience of the operator. Thus, unlike the conventional coating composition, a specific process for promoting the reaction between the binder resin and the appropriate amount of the curing agent, including an oxidation catalyst, and not adding many or excessive curing agents to the binder resin, It is possible to form a coating layer which gives stability of the solution by forming an environment in which the reaction is optimized.

Accordingly, the present invention provides a coating composition for forming a coating layer on one side or both sides of a polyester base film, comprising: 1 to 40% by weight of a polyacrylic resin; 0.25 to 15% by weight of a hardener; 0.1 to 5% by weight of an oxidation catalyst; 0.05 to 5 wt% wetting agent; 0.01 to 10% by weight of inorganic particles; 1 to 20% by weight of an alcoholic organic solvent; And 49 to 93.85% by weight of water, wherein the coating composition comprises the acidic adjusting agent in an amount such that the pH of the coating composition is 9 to 11 except for the oxidation catalyst, and a primer coating layer A polyester film is disclosed. First, components constituting the coating composition according to the present invention will be described in detail.

The base film on which the coating layer is formed by the coating composition according to the present invention is essentially composed of a polyester resin. In the present invention, the polyester resin can be obtained by polycondensing an aromatic dicarboxylic acid and an aliphatic glycol, Terephthalic acid, isophthalic acid, naphthalene dicarboxylic acid, cyclohexanedicarboxylic acid, diphenyldicarboxylic acid, and the like can be used without limitation, and the aliphatic glycol includes, but is not limited to, ethylene glycol, diethylene Glycol and the like can be used. Examples of such a polyester resin include polyethylene terephthalate and polyethylene-2,6-naphthalene dicarboxylate. However, the polyester resin is not limited thereto, and is preferably composed of polyethylene terephthalate in terms of balance of physical properties and cost , And the base film made of polyethylene terephthalate can be remarkably improved in chemical resistance, heat resistance, mechanical strength and the like by uniaxial or biaxial stretching.

The thickness of the polyester film applied to the present invention is not particularly limited, but can be determined arbitrarily according to a standard to be used in the range of several 탆 to several hundred 탆, specifically 5 to 500 탆. If the thickness of the film is less than 5 탆, rigidity or mechanical strength may be insufficient, and if it is more than 500 탆, transparency may be deteriorated and it may be disadvantageous in terms of cost efficiency.

The coating composition used for forming the primer coating layer on the polyester base film according to the present invention is based on a polyacrylic binder resin which basically serves as a binder for imparting the adhesiveness of the coating composition. Herein, the main component means a base resin except for additives among components excluding water, in a coating composition formed of a water dispersion-mixed liquid.

In the present invention, the polyacrylic binder resin may be at least one selected from the group consisting of methacrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, ethylhexyl methacrylate, phenyl methacrylate, Benzyl methacrylate, tolyl methacrylate, o-silyl methacrylate, glycerol methacrylate, ethylene glycol acrylate, ethylene glycol methyl acrylate, alkylaryl methacrylate, succinic methacrylate, glycidyl methacrylate Acrylate, styrene, and butyl acrylate. The content of each monomer is not particularly limited, but it is preferable that at least 90% by weight of the repeating units of the copolymer are methyl methacrylate And butyl acrylate, and the solution stability in the final product The weight ratio of methyl methacrylate to butyl acrylate is preferably from 1: 0.1 to 1: 1.2, more preferably from 1: 0.3 to 1: 0.8, most preferably from 1: 0.5 to 1: 0.6, . Herein, the polyacrylic binder resin may be at least one selected from the group consisting of hydroxyl methacrylate, acrylic acid, methacrylic acid, vinyl chloride, ethylene, vinyl acetate, acetate, vinyl versatate or the like may be further used to copolymerize the copolymer in an amount of 1 to 10% by weight.

In the present invention, the polyacrylic binder resin is contained in the coating composition in an amount of 1 to 40% by weight, preferably 2 to 20% by weight, more preferably 4 to 15% by weight. If the content of the polyacrylic binder resin is less than 1% by weight, the binder resin content is too low to uniformly form a thin coating layer during film coating, resulting in a lot of unevenness in the appearance, If it is more than 40% by weight, the coating layer becomes excessively thick due to the excessive content of the binder resin, and the viscosity of the coating solution may increase, and uneven coating may occur in the coating layer.

In addition, the polyacrylic binder resin is dispersed in a colloidal state in which the polyacrylic polymer contains water or the like as a dispersion medium, thereby imparting excellent adhesion to the film. Although the size of the polyacrylic colloid particles is not particularly limited, sedimentation does not occur during formation of the coating composition, and an average particle diameter of 10 to 200 nm is preferable for a remarkable effect to prevent foreign matter formation on the coating film, More preferably 50 to 100 nm, and most preferably 50 to 100 nm.

As described above, in the present invention, the polyacrylic binder resin maintains a certain dispersibility due to the colloidal state. Hydrolysis may occur due to the pH change of the coating composition, and the aggregation of the particles may occur. In the present invention, in order to prevent particle agglomeration during use of the polyacrylic binder resin, a small amount of an acidity regulator and a specific curing agent are used in consideration of phase stability, and a polyacrylic binder And the cross-linking agent can be optimized.

The acidity adjusting agent prevents the hydrolysis of the binder resin colloid in the emulsion state to improve the phase stability of the coating liquid and prevents the formation of foreign substances on the film due to the precipitation prevention, , Trimethylamine, methylamine, tetramethylammonium hydroxide, ammonia, potassium hydroxide, aminomethylpropanol, and the like, preferably triethylamine. At this time, in order to maintain the phase stability of the coating liquid most effectively in the composition of the present invention, the acid-adjusting agent content is such that the pH of the coating composition is 9 to 11, preferably 9.5 to 10.5 .

In the present invention, the curing agent is contained in an amount of 0.25 to 15% by weight, preferably 0.5 to 5% by weight, more preferably 1 to 3% by weight in the coating composition for curing between the polyacrylic binder resin and the film. If the content of the curing agent is less than 0.25% by weight, a sufficient curing reaction may not be exhibited and whitening may occur. If the content of the curing agent is more than 15% by weight, the coating layer may become hard and the adhesion may be reduced.

The curing agent is not particularly limited but is preferably a water-soluble thermosetting melamine resin, a water-soluble thermosetting melamine formaldehyde resin, an epoxy-based curing resin, a silane coupling agent, an aziridine-based curing agent, oxazoline-based curing agents, carbodiimide-based curing agents, blocked isocyanates, and the like.

In the present invention, the oxidation reaction between the curing agent is optimized, the reaction environment between the polyacrylic binder and the crosslinking agent is optimized, and the solution stability of the coating composition is maximized It is possible to obtain a polyester film having high quality and uniform appearance and adhesion even in a long-term operation.

The oxidation catalyst may be added in an amount such that the pH of the final coating composition is 7 to 8.5 for maximizing solution stability, and may be 0.1 to 5 wt%, preferably 0.5 to 3 wt% May be added in an amount of 1 to 2% by weight.

The oxidation catalyst is not particularly limited, but is preferably a hydrazide compound, a hydrazine compound, a hydroxylamine compound, an imide compound, an imide compound, an imine compound, a cyanate compound, an isocyanate Based compound, an isocyanide-based compound, and a thiocyanate-based compound may be used.

In the present invention, the wetting agent is added to the coating composition in an amount of 0.05 to 5% by weight, preferably 0.1 to 3% by weight, more preferably 0.2 to 3% by weight, based on the coating composition in order to improve the wetting properties of the two phases by changing the surface tension of the coating liquid, 1.5% by weight, and the alcoholic organic solvent is contained in an amount of 1 to 20% by weight, preferably 3 to 15% by weight, more preferably 5 to 10% by weight.

Examples of the wetting agent include, but are not limited to, a sulfosuccinate wetting agent, an alkyl alcohol wetting agent, an alcohol ethoxylate wetting agent, a fluorine wetting agent, a polysiloxane wetting agent, an acetylene glycol wetting agent, an ethylene glycol wetting agent, A phenol-based surfactant, a phenol-based surfactant, and a phenol-based surfactant. As the alcoholic organic solvent, for example, isopropyl alcohol may be used.

In the present invention, the inorganic particles are added to the coating composition in an amount of 0.01 to 10% by weight, preferably 0.05 to 5% by weight, more preferably 0.1 to 2% by weight, in order to impart the lubricity and prevent scratches in each step .

Examples of the inorganic particles include inorganic particles such as talc, silica, calcium carbonate, magnesium carbonate, barium carbonate, calcium sulfate, calcium phosphate, magnesium phosphate, kaolin, aluminum oxide, titanium oxide, zirconia, titania, Germanium, iron oxide, manganese dioxide, silicon carbide, copper oxide, cobalt oxide, nickel oxide, tin oxide, chromium oxide, zinc oxide, organic clay and the like can be used. The inorganic particles may have an average particle diameter of 0.005 to 3 탆, preferably 0.01 to 1 탆. When the average particle size of the inorganic particles is less than 0.005 탆, it may be difficult to impart the lubricity and prevent scratches sufficiently due to the mixing of the resin. When the average particle size exceeds 3 탆, the surface roughness of the film becomes too coarse, May be difficult, and when the hard coat layer or the like is formed in a post-process, adhesion and the like may occur.

The coating composition according to the present invention is prepared with a water dispersion mixture of 49 to 93.85% by weight, preferably 66.5 to 88.7% by weight of the above components and water. In addition, the coating composition according to the present invention may further contain another additive depending on each use within the scope of the present invention. As additional additives, a curing catalyst, a fluorescent dye, a plasticizer, an ultraviolet absorber, a pigment dispersant, a defoamer, and an antistatic agent may be added alone or in combination of two or more in a generally used range. 0.1 to 10 parts by weight based on 100 parts by weight of the composition.

The coating composition may be applied to one side or both sides of the polyester base film in a thickness of 1 to 20 탆, preferably 5 to 10 탆, and is preferably 10 to 1000 nm, more preferably 50 to 500 nm, When the coating layer is formed to have a thickness of 100 to 300 nm, sufficient adhesiveness can be exhibited while maintaining the optical properties of the polyester film. If the thickness after the drying is less than 10 nm, the adhesion may be deteriorated. If the thickness exceeds 1000 nm, the optical characteristics of the film may be deteriorated, and blocking may occur when the film is wound.

The method for forming the coating layer is not particularly limited as long as it is known in the art and includes, for example, coating using a roll such as a gravure roll, a reverse roll, a reverse gravure roll, A coating method using a bar such as a Meyer bar or a coating method such as an air knife method may be used.

The formation of the coating layer in the present invention can be performed, for example, by coating the film in-line after the film coating, for example, after the longitudinal stretching, or by applying an off-line coating after the biaxially oriented film is produced.

On the other hand, the production of the polyester base film is not particularly limited and may be carried out by a method commonly known in the art to which the present invention belongs. For example, polyethylene terephthalate is melt-extruded on a rotary cooling drum maintained at 15 to 25 ° C to prepare an unstretched film (sheet), subjected to 2 to 5 times of longitudinal stretching at 100 to 130 ° C, The film is transversely stretched at 2 to 5 times at 150 DEG C and heat-set at 200 to 260 DEG C to produce a biaxially stretched polyester film.

Hereinafter, a specific embodiment of the present invention will be described.

Example  One

I) 10% by weight of isopropyl alcohol (IPA) and 3 kinds of pure alkalis (alcoholic organic solvent) and 3% by weight of water-soluble thermosetting methylation melamine formaldehyde resin (solid concentration: about 98% Ii) a polyacrylic binder resin having an average particle diameter of 50 to 100 nm (methyl methacrylate and butyl acrylate monomers in a weight ratio of 1: 0.5 to 1: 1) in distilled water quantified as 73.1% by weight, : 0.6, solid content concentration of about 40% by weight) was added in an amount of 12% by weight, 0.2% by weight of a polysiloxane-based wetting agent was added, and 0.5% by weight of water-dispersed silica sol was added thereto under stirring at 300 rpm for 20 minutes or more Lt; / RTI > (Iii) triethylamine (triethanolamine) as an acidity regulator with i) solution was added to the solution, and the mixture was stirred at a speed of 300 rpm for 20 minutes or longer to prepare a coating composition which was a water dispersion mixture solution having a pH of 10. Iv) After that, the solution of iii) was added with a mixture of 0.2% by weight of a hydrazide-based oxidation catalyst and 1% by weight of a thiocyanate-based oxidation catalyst through a post-treatment to adjust the pH of the final coating composition to 8 before coating.

Example  2

A coating composition was prepared in the same manner as in Example 1 except that 9% by weight of an epoxy-based cured resin and 67.1% by weight of water were used instead of the water-soluble thermosetting methylation melamine formaldehyde resin.

Example  3

A coating composition was prepared in the same manner as in Example 1, except that 12 wt% of an oxazoline-based curing resin and 64.1 wt% of water were used instead of water-soluble thermosetting methylation melamine formaldehyde resin.

Example  4

A coating composition was prepared in the same manner as in Example 1 except that 0.5% by weight of an acetyl glycol wetting agent and 0.2% by weight of water-dispersible silicic acid were used instead of the polysiloxane wetting agent in Example 1.

Example  5

A coating composition was prepared in the same manner as in Example 1 except that 0.4 weight% of a hydrazide-based oxidation catalyst, 0.5 weight% of a thiocyanate-based oxidation catalyst and 73.4 weight% of water were used in Example 1.

Example  6

9 wt% of epoxy-based curing resin instead of water-soluble thermosetting methylation melamine formaldehyde resin in Example 1, 0.5 wt% of acetyl glycol wetting agent, 0.2 wt% of water-dispersed silica sol, 0.4 wt% of hydrazide- %, 0.5% by weight of a thiocyanate-based oxidation catalyst and 67.4% by weight of water were used.

Example  7

Except that 12% by weight of an oxazoline-based curing resin, 0.4% by weight of a hydrazide-based oxidation catalyst, 0.5% by weight of a thiocyanate-based oxidation catalyst and 64.4% by weight of water were used in place of the water-soluble thermosetting methylation melamine formaldehyde resin in Example 1 The coating composition was prepared in the same manner as in Example 1.

Example  8

The same procedure as in Example 1 was carried out except that 0.1% by weight of the polysiloxane wetting agent, 0.3% by weight of the acetyl glycol wetting agent, 0.4% by weight of the water-dispersed silica sol, 5% by weight of isopropyl alcohol and 78% To prepare a coating composition.

Comparative Example  One

A coating composition was prepared in the same manner as in Example 1 except that 16% by weight of water-soluble thermosetting methylation melamine formaldehyde resin and 60.1% by weight of water were used in Example 1.

Comparative Example  2

A coating composition was prepared in the same manner as in Example 1 except that 18% by weight of an epoxy-based curing resin and 58.1% by weight of water were used instead of the water-soluble thermosetting methylation melamine formaldehyde resin.

Comparative Example  3

A coating composition was prepared in the same manner as in Example 1, except that 24% by weight of an oxazoline-based curing resin and 52.1% by weight of water were used instead of the water-soluble thermosetting methylation melamine formaldehyde resin.

Comparative Example  4

6% by weight of an epoxy-based curing resin and 8% by weight of an oxazoline-based curing resin were used in Example 1, and the pH of the final coating composition was adjusted to 10 by using 60.3% by weight of water without using an oxidation catalyst , The coating composition was prepared.

Comparative Example  5

The same procedure as in Example 1 was carried out except that 9 wt% of the epoxy-based cured resin was used in Example 1 and the pH of the final coating composition was adjusted to 10 using 65.3 wt% of water without using an oxidation catalyst To prepare a coating composition.

Comparative Example  6

Same as Example 1 except that 12 wt% of the oxazoline-based curing resin was further used in Example 1 and the pH of the final coating composition was adjusted to 10 using 62.3 wt% water without using an oxidation catalyst To prepare a coating composition.

Comparative Example  7

9% by weight of an epoxy-based curing resin and 12% by weight of an oxazoline-based curing resin were used in place of the water-soluble thermosetting methylation melamine formaldehyde resin in Example 1, and 56.3% by weight of water The coating composition was prepared in the same manner as in Example 1 except that the pH of the coating composition was adjusted to 10.

Comparative Example  8

Except that 3% by weight of an epoxy-based curing resin and 4% by weight of an oxazoline-based curing resin were further added to 1% by weight of a water-soluble thermosetting methylation melamine formaldehyde resin in Example 1, and 68.1% 1, < / RTI >

The composition (unit: wt%) of the coating composition prepared according to the above Examples and Comparative Examples is shown in Table 1 below.

Test Example

In order to evaluate the optical characteristics, appearance and adhesion of a polyester film having a primer coating layer formed from the coating composition according to the present invention, a coating composition prepared according to Examples and Comparative Examples was used to form a primer coating layer To prepare a polyester film. The produced films were evaluated according to the following measurement methods, and the results are shown in Table 2 below.

[Film making and primer coating]

Polyethylene terephthalate was melt-extruded onto a rotating cooling drum maintained at about 20 캜 to produce an unoriented film. The unstretched film is heated to about 2 to 5 times in the longitudinal direction at 100 to 130 DEG C by heating with heated rolls and an infrared heater, and then the coating composition is coated on one side of the in-line longitudinally stretched polyester film, The film was cured by thermal drying at 250 ° C., stretched in the transverse direction about 2 to 5 times at 130 to 150 ° C., and heat-set at 200 to 260 ° C. to prepare a biaxially stretched polyester film.

[How to measure]

(1) Total light transmittance

Test method The total light transmittance of each polyester film was measured using a haze meter (NDH5000, Nippon Shokuhin Co., Ltd.) according to JIS K 7361.

(2) Haze

The haze of each polyester film was measured using a haze meter (NDH5000, manufactured by Nippon Shokuhin Co., Ltd.) according to the test method JIS K 7361.

(3) Appearance

The film was evaluated as permeation and reflection mode using a three-wavelength lamp in a dark room, and evaluated as good (.largecircle.) When there was no smear on the surface of the film, normal (.delta.) When slight smear was present and poor (X) when many smear was present.

(4) Adhesiveness

The photocurable acrylic resin (U117-3, manufactured by SKUCB) was applied to the # 12 Meyer bar and cured at an irradiation intensity of 200 mJ / cm 2 using a UV curing machine to form a hard coating layer having a coating thickness of 10 to 20 μm, The adhesion was evaluated as good (◯) when no peeling was observed, fair (△) when peeling off, and poor (X) when peeling was completely peeled.

(5) Humidity Resistance

The photocurable acrylic resin (U117-3, manufactured by SKUCB) was applied to the # 12 Meyer bar and cured at an irradiation intensity of 200 mJ / cm 2 using a UV curing machine to form a hard coating layer having a coating thickness of 10 to 20 μm, After 50 hours under an environment of 90% RH, the hard coat layer was evaluated for adhesion by a cross-hatch method, and a 24 mm wide tape (CELLOTAPE (registered trademark) CT-24 manufactured by Nichiban Co., Ltd.) (A) when no peeling was observed at all, (Δ) when peeling off partially, and (X) when peeling completely.

Referring to the above Table 2, it can be seen that a film prepared using a polyacrylic binder resin, a polysiloxane wetting agent, an aqueous dispersion silica sol, a hydrazide-based oxidation catalyst, a thiocyanate-based oxidation catalyst, IPA and an excessive amount of melamine- (Comparative Example 1) As the particle size of the polyacrylic binder resin increased due to excessive curing agent, it was found that many unevenness appeared on the appearance due to agglomeration, and the initial adhesion property was good, but the adhesion property was poor.

In the case of a film produced using a polyacrylic binder resin, a polysiloxane wetting agent, a water-dispersed silica sol, a hydrazide-based oxidation catalyst, a thiocyanate-based oxidation catalyst, IPA and an excess amount of an epoxy- ) As in Comparative Example 1, as the agglomerated particles were generated, it was found that the appearance was uneven and the optical characteristics, appearance, and adhesion properties were both lowered, and that the polyacrylic acid binder resin, polysiloxane wetting agent, In the case of a film produced using a catalyst, a thiocyanate-based oxidation catalyst, IPA and an excessive amount of an oxazoline-based cured resin composition (Comparative Example 3), as in Comparative Example 1, The optical characteristics, the appearance, and the adhesive properties are all lowered.

Further, in the case of films prepared using a coating composition containing multiple or large amounts of a curing resin and containing no oxidation catalyst (Comparative Examples 4 to 7), the crosslinking reaction between the binder and the curing agent was not sufficiently performed, , The optical characteristics and appearance were lowered, and it was found that the adhesive properties and the moisture resistance were poor.

Further, a coating composition using both a polyacrylic binder resin, a polysiloxane-based wetting agent, a water-dispersed silica sol, a hydrazide-based oxidation catalyst, a thiocyanate-based oxidation catalyst, IPA and melamine-based, epoxy- In the case of the produced film (Comparative Example 8), relatively good optical characteristics and adhesion characteristics were observed, but appearance and long-term moisture resistance were slightly lowered.

On the other hand, it can be confirmed that the primer-coated film (Examples 1 to 8) with the coating composition of the composition range according to the present invention retains the optical characteristics of the polyester base film while having excellent appearance, adhesion property, .

The preferred embodiments of the present invention have been described in detail above. It will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Accordingly, the scope of the present invention is defined by the appended claims rather than the foregoing detailed description, and all changes or modifications derived from the meaning, range, and equivalence of the claims are included in the scope of the present invention Should be interpreted.

Claims (11)

A method for producing a coating composition for forming a coating layer on one side or both sides of a polyester base film,
(a) preparing a first mixed solution containing 1 to 20% by weight of an alcoholic organic solvent and 0.25 to 15% by weight of a curing agent;
(b) A second mixed solution is prepared by adding and stirring to 49 to 93.85% by weight of water, 1 to 40% by weight of a polyacrylic resin, 0.05 to 5% by weight of a wetting agent and 0.01 to 10% Preparing a second mixed solution such that the particles are dispersed in a colloid state using the water as a dispersion medium, the particles having an average particle diameter of 10 to 200 nm;
(c) adding the first mixed solution and an acidity adjusting agent for preventing hydrolysis of the colloid to the second mixed solution and stirring the mixture to prepare a water dispersion mixed solution having an acidity (pH) of 9 to 11; And
(d) 0.1 to 5% by weight of an oxidation catalyst is added to the aqueous dispersion mixture to reduce the reaction between the polyacrylic resin and the curing agent to promote the reaction between the polyacrylic resin and the curing agent to obtain a water dispersion mixture solution having an acidity (pH) Producing;
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Wherein the acidity regulator is at least one selected from the group consisting of triethylamine, trimethylamine, methylamine, tetramethylammonium hydroxide, ammonia, potassium hydroxide and aminomethylpropanol, and the oxidation catalyst is at least one selected from the group consisting of a hydrazide compound, Based compound, an isocyanide-based compound, and a thiocyanate-based compound selected from the group consisting of an amine-based compound, a hydroxylamine-based compound, an imide-based compound, an imide-based compound, an imine compound, a cyanate compound, an isocyanate compound, By weight based on the weight of the aqueous dispersion. delete The method according to claim 1,
The polyacrylic resin may be at least one selected from the group consisting of methacrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, ethylhexyl methacrylate, phenyl methacrylate, benzyl methacrylate, , Tolyl methacrylate, o-silyl methacrylate, glycerol methacrylate, ethylene glycol acrylate, ethylene glycol methyl acrylate, alkylaryl methacrylate, succinic methacrylate, glycidyl methacrylate, styrene and Butyl acrylate are copolymerized with each other in the presence of an acid catalyst. delete The method according to claim 1,
The curing agent is selected from the group consisting of a water-soluble thermosetting melamine resin, a water-soluble thermosetting melamine formaldehyde resin, an epoxy curing resin, a silane coupling agent, an aziridine curing agent, an oxazoline curing agent, a carbodiimide Wherein the polymer is at least one selected from the group consisting of a curing agent and a blocked isocyanate. delete The method according to claim 1,
The wetting agent is selected from the group consisting of a sulfosuccinate wetting agent, an alkyl alcohol wetting agent, an alcohol ethoxylate wetting agent, a fluorinated wetting agent, a polysiloxane wetting agent, an acetylene glycol wetting agent, an ethylene glycol wetting agent and an alkylene glycol monoalkyl ether wetting agent Wherein the water-dispersible polymer coating composition is at least one selected from the group consisting of polyvinyl alcohol and polyvinyl alcohol. The method according to claim 1,
The inorganic particles may be at least one selected from the group consisting of talc, silica, calcium carbonate, magnesium carbonate, barium carbonate, calcium sulfate, calcium phosphate, magnesium phosphate, kaolin, aluminum oxide, titanium oxide, zirconia, titania, mica, ceresite, cordierite, Wherein at least one selected from the group consisting of manganese dioxide, silicon carbide, copper oxide, cobalt oxide, nickel oxide, tin oxide, chromium oxide, zinc oxide and organic clay is used. delete delete delete