KR20160010048A - Manufacturing method of primer resin for optical pet film - Google Patents

Abstract

Disclosed is an acrylic polymer resin represented by chemical formula 1, which is a resin for an optical PET film surface protecting layer, wherein the molar ratio of a glycidyl-based monomer ranges from 50% to 70% with respect to the total monomer of a glycidyl-based monomer and a nonglycidyl-based monomer in a molecule. In chemical formula 1, R1, R2, and R3 are identical or different and represent -H or -CH3; R4 and R5 are identical or different, represent an alkyl group or a glycidyl group, and do not comprise -H and -ROH; m and n are each an integer greater than or equal to 1, and satisfies an inequality, m>=n; and n satisfies an inequality, n = x + Y. The resin according to the present invention is a solvent-type binder including a glycidyl group of 50% or more on a basis of molar ratio in a molecule, and can be used in a one-component type, a two-component type and a UV curing type. Also, the resin is used in alone or in combination for various paints, thereby improving adhesion of a dried paint film and reducing shrinkage of the dried paint film. The resin can be used as a primer for a PET material when coated alone. Also, in the case of a high-hardness UV paint for PET material surface protection, the resin is added to the paint and mixed, thereby being effective in overcoming the film shrinkage and adhesion failure of a cured paint film.

Description

Technical Field [0001] The present invention relates to a primer resin for an optical PET film protective layer,

TECHNICAL FIELD The present invention relates to a primer resin (binder) excellent in adhesion to a polyester film (PET) used for optical purposes, having a small shrinkage ratio and easy to be re-coated, and a method for producing the same.

Conventionally, surface pretreatment is performed by chemically or physically etching the surface of a plastic material so as to facilitate coating.

However, despite these pretreatment processes, the adhesion between the plastic substrate and the paint is not completely solved. Especially, UV resin, which is widely used in the optical film field, has a low flexibility in spite of its excellent physical properties and its use is limited due to a large shrinkage rate generated during curing.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and an object of the present invention is to provide an excellent PET film capable of improving adhesion and dimensional stability (shrinking of a dry film and curling of the film caused thereby) (A primer resin or a coating resin composition) for a surface protective layer.

The above object of the present invention is also achieved by a primer resin for an optical PET film surface protective layer, wherein the molar ratio of the glycidyl monomer to the entire monomers of the glycidyl monomer and the biglycidyl monomer in the molecule is in the range of 50% to 70% 1 > and R < 2 >

(Formula 1)

Here, R ₁ , R ₂ and R ₃ are the same or different and represent -H and -CH ₃ .

R ₄ and R ₅ are the same or different and each represents an Alkyl or Gylcidyl group.

R ₄ and R ₅ do not include a -H, -ROH group.

m and n are each an integer of 1 or more, and m ≥ n.

n = x + Y.

The non-volatile content of the resin is adjusted to 50 to 95 wt% by appropriately controlling the molecular weight according to the manner of use.

The resin may be adjusted to have a molecular weight of 8,200 (low viscosity, high solids content) to 16,000 (high viscosity, low solids content) depending on the intended use.

According to the experiments of the present inventors, it was found that the produced resin exhibited favorable drying characteristics in the form of a high viscosity (low nonvolatile content) during the production of a thermal drying type paint, and a low viscosity (high nonvolatile content) type in a UV- Drying properties.

The content of glycidyl group which effectively improves the adhesion to the PET material in the above formula (1) is more than 50% (m≥n) in terms of the total amount of monomers used, but as the glycidyl group content increases It was found that the difficulty in the production of the reproducible polymer was increased due to the increase of the side reaction. In the present invention, it is preferable that the composition ratio of the glycidyl group GMA for the uniform physical property reproduction is limited to a range of 50 to 70% as a percentage (GMA monomer mole / total monomer mole number) with respect to the total amount of monomers used.

The resin of the present invention is prepared by mixing Glycidyl methacrylate with various acryl monomers and reacting them in the presence of an initiator. In the acrylic monomer, a side reaction may occur due to reaction with a glycidyl group The monomer having -COOH or -OH group is excluded.

On the other hand, the initiator may be an azo compound, specifically, 2,2'-azobisisobutyronitrile (2,2'-azobisisobutyronitrile).

In the production of the resin of the present invention, it is preferable that the reaction temperature is 70 ± 2 ° C., and the reaction time after completion of the monomer addition is maintained at 70 ± 2 ° C. for 6 hours or more.

As a method of the present invention, a method in which a 1-molar amount of glycidyl methacrylate (GMA) is added to 1 mol of Glycidyl methacrylate (GMA), which is composed of BMA (Buthyl metaacrylate), 2-HEMA (2-Hydoxyethyl metaacrylate), n- 1 mol of the monomer selected from the silydyl monomer group is mixed with 0.1 mol of AIBN (2,2'-Azobisisobutyronitrile) to prepare a mixed solution. The mixed solution is put into a solvent which is maintained at a temperature of 70 ± 2 ° C., A method of producing the compound of formula (1) of the present invention by cooling at room temperature (30 DEG C or less) after maintaining the reaction for 6 hours or more in the temperature range is exemplified.

The resin of the present invention is a solvent type binder containing 50% to 70% of glycidyl groups in a mole ratio within a molecule, and can be used in one-component type or two-component type and UV curing type. Improves adhesion and reduces shrinkage.

In case of coating alone, it can be used as a primer in PET material, and in case of high-hardness UV paint for surface protection of PET material, it can be added and mixed with the paint to compensate film shrinkage and adhesion defect problem of cured film.

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

1. Production of resin of the present invention

(Example 1)

(0.067 mole) of AIBN (2,2'-Azobisisobutyronitrile. CAS No: 78-67-1), 142.0 g (Solution A) was prepared.

-DMC (Di-methyl carbonate) were preliminarily weighed in a four-necked flask, and then the temperature was raised to 70 DEG C with stirring.

- Mix the solution (A solution) slowly by dropping for 150 min. The temperature was maintained at 70 ± 2 ℃.

After the dropping, the reaction was maintained for 6 hours in the temperature range of 70 ± 2 ° C.

After cooling to room temperature (30 ° C or lower), the resin was filtered through a # 200 mesh screen to obtain a resin of formula (1) of the present invention.

The prepared resin was a hazy transparent liquid phase. The prepared resin was allowed to stand at room temperature for 3 months or longer, and it was confirmed that no side effects such as viscosity increase and gelation occurred during storage. It was found that the final viscosity of the resin was reduced when the weight of the initiator (e. G., 8 g, 0.05 mole) was increased during the above reaction and conversely the weight of the initiator (e. G., 16 g, 0.1 mole) decreased the final viscosity of the resin.

In the above reaction, the amount of the initiator used may be increased or decreased sequentially to select a resin having a viscosity suitable for preparing the paint. The content of the final initiator used in the examples of the present invention was determined to be 11 g (0.067 mol).

(Example 2)

(A) of 142.0 g (1 mole) of GMA (Glycidyl meta Acrylate), 130.0 g (1 mole) of 2-HEMA (2-Hydoxyethyl metaacrylate) and 11 g (0.07 mol) of AIBN (2,2'-Azobisisobutyronitrile) Solution) was prepared.

-Buthyl-acetate was preliminarily weighed into a four-necked flask, and then the temperature was raised to 70 DEG C with stirring.

- Slowly drop the mixed solution (liquid A) for 90 min. The temperature was maintained at 70 ± 2 ℃.

After the dropping, the reaction was maintained for 6 hours in the temperature range of 70 ± 2 ° C.

- After cooling to room temperature (below 30 ℃), it was filtered with a # 200 mesh net.

Through the above reaction process, a stable transparent liquid-like resin part of the present invention represented by the formula (1) was prepared. The same procedure as in Example 1 was carried out for 3 months or more at room temperature. Viscosity increased with time at storage at room temperature, and gelation was observed after 4 months.

(Example 3)

(1 mole) of GMA (Glycidyl meta Acrylate) and 128.0 g (1 mole) of n-butyl acrylate monomer, and AIBN (2,2'-Azobisisobutyronitrile. CAS No. 78-67-1) 8.2 g (0.05 mol) of a mixed solution (solution A) was prepared.

-DMC (Di-methyl carbonate) were preliminarily weighed in a four-necked flask, and then the temperature was raised to 70 DEG C with stirring.

- Slowly drop the mixed solution (liquid A) for 90 min. The temperature was maintained at 70 ± 2 ℃.

After the dropping, the reaction was maintained for 6 hours in the temperature range of 70 ± 2 ° C.

- After cooling to room temperature (below 30 ℃), it was filtered with a # 200 mesh net.

Through the above reaction process, a resin part of the present invention represented by the formula (1) was prepared in the form of a hazy transparent liquid. The same procedure as in Example 1 was carried out at room temperature for 3 months or more. In this case, it was confirmed that no side effects such as viscosity increase and gelation occurred during storage.

(Example 4)

(1 mole) of GMA (Glycidyl meta acrylate), 72.0 g (1 mole) of AA (Acrylic Acid) and 11 g (0.07 mole) of AIBN (2,2'-Azobisisobutyronitrile. CAS No: 78-67-1) (Liquid A) was prepared.

-Iso-propyl alcohol (IPA) was preliminarily weighed in a four-necked flask, and the temperature was raised to 70 DEG C while stirring.

- Slowly drop the mixed solution (liquid A) for 90 min. The temperature was maintained at 70 ± 2 ℃.

After the dropping, the reaction was maintained for 6 hours in the temperature range of 70 ± 2 ° C.

- After cooling to room temperature (below 30 ℃), it was filtered with a # 200 mesh net.

In the above reaction process, exothermic and gelation proceeded from the middle of the monomer introduction, and the gelation proceeded completely at the completion of the monomer addition.

Influence of temperature on resin production.

In the case of a resin part not containing GMA (Glycidyl meta acrylate), a stable polymerization reaction proceeds at a temperature of about 60 to 80 ° C. However, when GMA was added in excess, irregular exothermic reactions and side effects such as gelation and precipitation occurred very frequently.

When the GMA and the general monomer were fixed at a molar ratio of 1: 1 and the initiator was limited to AIBN (2,2'-Azobisisobutyronitrile), this irregularity was somewhat alleviated, but gelation occurred depending on the reaction temperature.

(Results of polymerization progression according to temperature (initiator: AIBN))  division Temp-1 Temp-2 Temp-3 Reaction temperature range 60 to 67 ° C 68 ~ 74 ℃ 75 ~ 80 ℃ When the monomer mixture liquid is supplied
Temperature change
(Injection time: 90 to 120 minutes) No temperature change Minor outbreak
Periodic cooling required Explosive fever progression.
Gelation occurs during the injection of the mixed solution or at the end of the injection. Coating property when drying naturally after coating on glass plate with Mayer bar # 5. Undried or sticky residue. Adhesionless dry film formation. No coating.

The temperature control during the preparation of the polymer containing GMA is very important, and it has been verified through various experiments that the proper reaction temperature range is 70 ± 2 ℃.

Resin part  During manufacture Post reaction  Time impact

In the case of a general acrylic polymer, the remaining amount of the unreacted monomer is removed by maintaining the post-reaction for 2 to 4 hours after the monomer is introduced. In the manufacturing process of the present invention, the post-reaction time was also different in the condition of maintaining the temperature lower than the general reaction temperature. After completion of the monomer addition, the liquid phase viscosity inside the reactor was visually observed with the lapse of time while maintaining the temperature of the reactor at 70 ± 2 ° C for the post-

As a result, Examples 1, 2 and 3 show similar cases, and the phenomenon is summarized in Table 2.

(Variation of Flow Characteristics of Liquid with Post-Reaction Time) Elapsed time after completion of input
time Appearance observation result 1 to 2 hours Maintain a low viscosity liquid without any change. 2 to 4 hours The viscosity of the solution decreases and the viscosity gradually decreases. 4 to 6 hours Reduced liquid flow due to a pronounced increase in viscosity. 6 to 8 hours The viscosity increase rate is slowed and the flowability of the liquid phase is stabilized. 8 to 10 hours If the viscosity of the liquid does not change by visual observation, start cooling. Completion of filter after cooling.
3 months storage at room temperature Stable storage stability without occurrence of thickening or gel.

It was confirmed that the reaction time of 6 hours or more was given to the point where there was no further change of viscosity through various experiments. When the post reaction time was maintained for 2 hours and 4 hours and then the filter was cooled, bar # 5 and dried naturally, drying phenomenon such as tackiness frequently occurred on the surface dried state. After cooling, the viscosity was also very low. However, stability of the liquid phase was very poor, for example, when the sample was allowed to stand at room temperature for 3 months, the sample was thickened and some samples were kept at a low point.

In the initiator  Influence by

The type of initiator that can be used in the reaction for preparing the resin of the present invention is limited to azo compounds, and in the examples, AIBN (Azobisisobutyronitrile) was used.

GMA contains a gylcidyl group. In order to improve the adhesion with the PET material, improve the impact resistance, and alleviate the contraction rate of the dried coating film, it is important to retain as much Glycidyl groups as possible in the final polymer or oligomer molecule.

However, in preparing the resin of the present invention, a stable polymer (or oligomer) is prepared by using sulfur based peroxide (SPS: Potassium persulfate, APS; Ammonium persulfate, etc.) capable of cationic reaction with the Glycidyl group as an initiator It is difficult to do.

The following comparative examples were tested to compare the effect of the initiator in the previous examples for making the resin of the present invention.

(Example 5)

(A solution) of 142.0 g (1 mole) of GMA (Glycidyl meta Acrylate), 142.0 g (1 mole) of BMA (Buthyl metacrylate) and 9.8 g (0.07 mol) of AIBN (2,2'-Azobisisobutyronitrile) Prepared.

-Iso-propyl alcohol (IPA) was preliminarily weighed in a four-necked flask, and the temperature was raised to 70 DEG C while stirring.

- Slowly drop the mixed solution (liquid A) for 90 min. The temperature was maintained at 70 ± 2 ℃.

After the dropping, the reaction was maintained for 6 hours in the temperature range of 70 ± 2 ° C.

- After cooling to room temperature (below 30 ℃), it was filtered with a # 200 mesh net.

(Comparative Example 1)

(A solution) of 142.0 g (1 mole) of GMA (Glycidyl meta Acrylate), 142.0 g (1 mole) of BMA (Buthyl metaacrylate) and 15.9 g (0.07 mole) of APS (Ammonium persulfate)

-Iso-propyl alcohol (IPA) was preliminarily weighed in a four-necked flask, and the temperature was raised to 70 DEG C while stirring.

- Slowly drop the mixed solution (liquid A) for 90 min. The temperature is controlled within the range of 70 ± 2 ℃.

- After termination of the dropping, the reaction is maintained for 6 hours in the temperature range of 70 ± 2 ℃.

- Cool at room temperature (below 30 ℃) and filter with a # 200 mesh net.

In Example 5, a stable liquid phase similar to Examples 1 and 3 was obtained,

In the case of Comparative Example 1, an explosive exothermic heat (a temperature rise from 75 ° C to 190 ° C in about 5 minutes) was generated in the latter half of the monomer injecting process, and a large amount of steam was ejected, and at the same time, gelation occurred.

In order to slow down the reaction rate, similar results were obtained when the reaction was carried out at 60 to 65 ° C. When the reaction temperature was lower than 60 ° C, the reaction did not proceed. When the unreacted liquid was allowed to stand at room temperature for 12 hours or more, But the viscosity did not increase. This indicates that the radicals obtained by the decomposition of sulfur peroxide by heat have different properties than the radicals produced by AIBN. The reason is unknown, but the radicals generated from sulfur peroxide are presumed to vigorously accelerate both the radical reaction attacking the double bonds in the monomer as well as the cationic reaction to decompose the glycidyl group.

(Example 6): Preparation of a resin having a high solid content

(A) of 142.0 g (1 mole) of GMA (Glycidyl meta Acrylate), 142.0 g (1 mole) of BMA (Buthyl metaacrylate) and 16.0 g (0.1 mole) of AIBN (2,2'-Azobisisobutyronitrile) And

50 g of IPA (Iso-propyl alcohol) was preliminarily measured in a four-necked flask, and the temperature was raised to 70 DEG C with stirring.

- Mix the solution (A solution) slowly by dropping for 120 minutes. The temperature was maintained at 70 ± 2 ℃.

After the dropping, the reaction was maintained for 6 hours in the temperature range of 70 ± 2 ° C.

- After completion of the post-reaction, vacuum is applied while maintaining 70 ° C to remove the solvent as much as possible.

- After cooling to room temperature (below 30 ℃), it was filtered with a # 200 mesh net.

The resin of Formula 1 of the present invention in a stable liquid state was prepared by the above method. A liquid having a relatively high viscosity and flowability still retained at 95% (120 DEG C x 30 minutes) or more was obtained as compared with Example 1.

Table 3 below summarizes the properties of the resins prepared above.

division Example 1 Example 2 Example 3 Example 4 Example 5 Implementation 6 Exterior haze clear haze clear clear clear importance Initial viscosity (30 degrees) 750 cps Gelling 1200 cps Gel generation 1,000 cp.s 13,000 cps After storage viscosity No change Gelling No change Impossible No change No change NV (%) 54% 53% 52% - 55% 87% Painting conditions 1-part type (no curing agent used), wire bar # 5, 60 占 폚 占 1 minute, Stickiness none none none Impossible none has exist Hardness 1H to 2H 1H to 2H 1H to 2H Impossible 1H to 2H Not measurable Solvent resistance (IPA 10 times) Good usually Good Impossible Good Poor

* 1 for comparison is not available due to manufacturing failure.

In Example 4, a resin was prepared in the case of using acrylic acid (-COOH), but the viscosity was irregular even during the reaction and the completion of the reaction was almost gelled. In the case of Example 2, 2-HEMA (-OH) It was also confirmed that it is very unstable. In these two cases, when a monomer having -COOH or -OH group is used, it is preferable that the glycidyl group is an acid (-COOH) or an alcohol (-COOH) group together with a general reaction in which monomers are polymerized by breaking the double bond (unsaturated group) (-OH) transient reaction occurs and the side effect of the gel proceeds.

From the above, it can be summarized that the following conditions must be satisfied in order to produce the acrylic polymer (Formula 1) of the present invention containing a large amount of glycidyl groups.

Manufacturing conditions of resin part. One Initiator Initiators are limited to azo compounds. 2 Reaction temperature The reaction temperature is 70 ± 2 ℃. 3 Reaction time The post-reaction time is maintained at a temperature range of 70 ± 2 ° C for more than 6 hours. 4 Monomers to avoid Monomers containing alcohol (-OH) and acid (-COOH) are not mixed with Glycidyl-based monomer. 5 Mixing ratios of preferred monomers The mole ratio of the glycidyl monomer to the non-glycidyl monomer is suitably in the range of 1: 1 (50%) to 2: 1 (70%).
(Molar ratio (%) = mole number of Glycidyl monomer / (mole number of Glycidyl monomer + total mole number of non-Glycidyl monomer) x 100)

If all of the above conditions are met, a polymer or oligomer of formula (1) wherein the content of glycidyl groups in one molecule is 50% -70% (on a molar basis) can be prepared.

2. Curing method of resin of the present invention

The resin of the present invention is a solvent type binder containing 50% -70% of glycidyl groups in a mole ratio within a molecule, and can be used in one-component type or two-component type and UV curing type. Improves adhesion and reduces shrinkage.

In case of coating alone, it can be used as a primer in PET material. In case of high-hardness UV paint for surface protection of PET material, it can be added and mixed with paint to compensate film shrinkage and adhesion defect problem of cured film.

This will be described in detail below.

2.1. One-component type heat drying (resin part alone, non-reaction type)

The resin was diluted with a solvent such as DMC or NMP and coated on a PET material with Mayer bar # 3 to 5 (humidity film 6.86 to 9.14 μm), dried at 100 to 120 ° C. for 1 minute, and aged at 40 ° C. for 24 hours .

In the case of Examples 1, 3 and Example 5 (Example 5), the drying by evaporation of the solvent by heating is used as the basic curing method. However, a hardener may be introduced to improve the chemical properties of the dried coating surface.

Example 6 can not be cured by a natural drying method, and can be cured into a reaction type into which a curing agent is introduced.

2.2 Mixed Curing Method with Acrylic Polymer (Reaction Type)

For the curing reaction, a polymer represented by the following formula (2) containing a large amount of -COOH in the molecular structure can be used as a curing agent. The carboxylic acid (-COOH) in the curing agent part reacts with the Gylcidyl group in the resin part, Go ahead. Suitable reaction temperatures are above 80 ° C and 120 ° C.

(2)

Here, -H and -COOH may be present singly or may be present together. Representative polymers include AA (Acryl Acid) homopolymer or a mixed polymer of AA (Acryl Acid) and MA (maleic acid). There are many commercially available products and are readily available.

The polymer for the hardener of the formula (2) can be synthesized in a general solvent system or an alcohol system using AIBN or APS. In the water system, the polymer can be neutralized with an alkali to be used as a dispersant of an inorganic pigment. It is a product group commonly used as alkali neutralizing type thickener.

The following scheme 1 is a curing reaction of a glycidyl group with a carboxylic acid.

(Scheme 1)

(Acid) (Glycidyl)

Examples of use of a resin part and a hardener mixture,

The coating was applied to a plasma pretreated PET film with Mayer bar # 5 (humidity film 9.14 μm) at a ratio of resin: acrylic acid hardener = 2 to 4: 1, dried at 120 ° C. for 1 minute, and aged at 40 ° C. for 24 hours Go ahead.

In this case, a product of Synthro-PON LP0027 (Protex Korea) was used as a hardener. Various types of catalysts can be used. In the examples of the present invention, ANKAMINE K-54 (Air Products) is used, but the catalyst is not limited to specific catalysts. (For example, Ankamine K54, PTSA- etc.)

(Non-reactive dry and reactive dry test) ingredient Formulation Example Solution A Formulation example B liquid Remarks In Example 1, 100 100 NMP 20 20 Basf Synthro-PON LP0027 25 Protex Korea ANKAMINE K-54 1.5 Air products Sum 120 146.5

(Experiment result) division Formulation Example Solution A Formulation example B liquid Remarks Shrink none none Visual judgment Solvent resistance (IPA, 10 times) Good Good 200g weight / Rub-out 10 times Attach 100/100 100/100 Tape peeling after cross cut

2.3. Cationic UV curing method.

100 g of the reactive monomer (CYRACURE UVR-6110) was mixed with 100 g of the resin part of Example 1, and 3 g of a cationic initiator (Irgacure 250, BASF Corp.) was mixed.

- Coat with Mayer bar # 3 ~ 5 (humidity film 6.86 ~ 9.14㎛) and dry at 60 ℃ for 1 minute.

- After that, cure to 1000 mJ / cm ² with 700W / cm UV-B type lamp.

(Cationic UV curing test) ingredient Formulation example C solution Formulation example D solution Remarks In Example 1, 50 - CYRACURE UVR-6110 50 100 Irgacure 250 3 3 Ciba-specialty chemical Sum 120 146.5

(Experiment result) division Formulation example C solution Formulation example D solution Remarks Shrink none Almost none Visual judgment Solvent resistance (IPA, 10 times) Good Good 200g weight / Rub-out 10 times Attach 100/100 90/100 Tape peeling after cross cut

2.4. A method of improving adhesion of radical-based high-hardness UV paint and solving the shrinkage problem of film.

The resin of the present invention alleviates the shrinking and curling phenomenon of the dried coating film after UV drying of the radical-based high-hardness UV coating material, which has not been solved up to now by a high-hardness UV coating material using a monomer having a polyfunctional functional group Can be used to contribute to enhancing adhesion.

A film made of a general high-hardness UV paint containing a polyfunctional monomer (for example, PETA-Pentaerythritoltetacrylate) has advantages of excellent solvent resistance, scratch resistance, and transmittance, while film shrinkage after curing and adherence and flexibility I have a problem of badness. The disadvantages of the high hardness UV coating can be compensated for by mixing the resin part prepared in Example 6 of the present invention with the conventional high hardness UV coating in the range of 10 to 50% by weight. DPHA (Dipentaerythritolhexaacrylate.) And PETA can be used as high-hardness UV paints. Irgacure-184 (BASF Corp.) and TPO can be used as an initiator.

Further, when a resin portion of 20 to 50% of the nonvolatile matter of the high hardness UV resin is used, the problem of shrinkage of the film, adherence to the substrate and flexibility can be alleviated.

In order to measure the intuitive effect of improving shrinkage-preventing adhesion, the following experiment was conducted.

ingredient Formulation Example Solution A Formulation example B liquid Remarks In Example 6, 50 - Miramer M600 50 100 Dipentaerythritolhexaacrylate Irgacure-184 3 3 BASF Corp. Lucirin TPO One One Irgacure 250 One One BASF Corp. Sum 105 105

The PET film pretreated with Mayer bar # 5 was painted and then cured to 1000 mJ / cm ² with a 700 W / cm UV-B type lamp. This curing reaction is a traditional hybrid reaction of radical UV and cation UV coatings.

(Experiment result) division Formulation Example Solution A Formulation example B liquid Remarks Shrink none has exist Visual judgment Picture Solvent resistance (IPA, 10 times) Good Good 200g weight / Rub-out 10 times Attach 100/100 80/100 Tape peeling after cross cut

.

Claims (3)

An acrylic polymer for an optical PET film surface protection layer, which comprises an acrylic polymer represented by the following formula (1) having a molar ratio of a glycidyl monomer to an entire monomer of a glycidyl monomer and a biglycidyl monomer in a molecule of 50% to 70% Suzy.

Here, R ₁ , R ₂ and R ₃ are the same or different and represent -H and -CH ₃ .
R ₄ and R ₅ are the same or different and each represents an Alkyl or Gylcidyl group.
R ₄ and R ₅ do not include a -H, -ROH group.
m and n are each an integer of 1 or more, and m ≥ n.
n = x + Y. A method for producing an acrylic polymer resin according to claim 1,
The monomer having -COOH or -OH group, which can react with a glycidyl group to generate a side reaction, is prepared by mixing glycidyl methacrylate with an acryl monomer in the presence of an azo compound. Excluded,
The molar ratio of the glycidyl monomer to the biglycidyl monomer is maintained at 1: 1 to 2: 1 at a temperature of 70 ± 2 ° C, 1. ≪ / RTI > Wherein the composition further comprises 10 to 50% by weight of the resin of claim 1 or 2 based on 100 parts by weight of the UV curable coating composition containing DPHA or PETA.