KR102105089B1 - Photocurable composition for polarizer protection film and polarizing film comprising polarizer protection film comprising cured product thereof - Google Patents

Abstract

One embodiment of the present invention is a monomer mixture containing an alicyclic functional group-containing (meth) acrylate monomer, an aliphatic functional group-containing (meth) acrylate monomer, a polar functional group-containing (meth) acrylate monomer, and an aliphatic functional group-containing acrylamide monomer. Derived polymers; And it includes a curing agent, the glass transition temperature of the polymer is 50 ℃ to 65 ℃ to provide a photocurable composition for a polarizer protective film.

Description

A photocurable composition for a polarizer protective film and a polarizer protective film comprising a polarizer protective film comprising a cured product thereof

The present invention relates to a polarizing film comprising a polarizer protective film comprising a photocurable composition for a polarizer protective film and a cured product thereof.

Optically functional films are widely used as parts of display devices, etc. In particular, polarizing films can play a role of selectively passing only light that vibrates in one direction out of light that vibrates in all directions. It is widely used in. Moreover, since the polarizing film can determine the passage and blocking of light when placed in a pair, it has recently been used as an essential component of various display devices such as TVs, monitors, laptops, digital cameras, and mobile phones.

Polarizing films are necessarily used in these display devices to show optical properties, and polarizing films generally protect ionic (I ₂ ) or dichroic dyes from polyvinyl alcohol (Poly Vinyl Alcohol) polarizers and polarizers. A protective film is included.

Conventionally, in order to manufacture a polarizing film, a polarizer protective film was attached to one surface of the polarizer using an adhesive or an adhesive film. In order to attach the polarizer protective film to one surface of the polarizer, a process of applying an adhesive on the polarizer protective film or attaching the adhesive film, and then bonding the polarizer protective film on the polarizer was performed. However, the above-described process of attaching the polarizer protective film on the polarizer has a disadvantage of increasing the manufacturing time of the polarizing film, and there is a problem that a defect may occur in the polarizing film in the process of attaching the polarizer protective film.

Accordingly, there is a need for a technology capable of easily forming a polarizer protective film on a polarizer.

This specification is intended to provide a polarizing film comprising a polarizer protective film comprising a photocurable composition for a polarizer protective film and a cured product thereof.

However, the problem to be solved by the present invention is not limited to the above-mentioned problems, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.

One embodiment of the present invention is a monomer mixture containing an alicyclic functional group-containing (meth) acrylate monomer, an aliphatic functional group-containing (meth) acrylate monomer, a polar functional group-containing (meth) acrylate monomer, and an aliphatic functional group-containing acrylamide monomer. Derived polymers; And it includes a curing agent, the glass transition temperature of the polymer is 50 ℃ to 65 ℃ to provide a photocurable composition for a polarizer protective film.

In addition, another embodiment of the present invention provides a polarizer protective film comprising a cured product of the photocurable composition for the polarizer protective film.

In addition, another exemplary embodiment of the present invention provides a polarizing film including the polarizer protective film.

An exemplary embodiment of the present invention is a polarizer; And a polarizer protective film including a cured product of the photocurable composition for the polarizer protective film provided on at least one surface of the polarizer.

In addition, another embodiment of the present invention provides a method of manufacturing a polarizing film.

One embodiment of the present invention comprises the steps of preparing a polarizer; Applying a photocurable composition for a polarizer protective film on one surface of the polarizer; And curing the light-curable composition for the polarizer protective film; provides a method for producing a polarizing film comprising a.

The photocurable composition for a polarizer protective film according to an exemplary embodiment of the present invention may provide a polarizer protective film having excellent durability.

The photocurable composition for a polarizer protective film according to an exemplary embodiment of the present invention may provide a polarizer protective film having excellent adhesion to a polarizer.

The polarizer protective film according to an exemplary embodiment of the present invention may have excellent adhesion and durability to the polarizer.

The method of manufacturing a polarizing film according to an exemplary embodiment of the present invention can easily manufacture a polarizing film including a polarizer protective film having excellent durability.

Throughout the present specification, when a part “includes” a certain component, it means that the component may be further included other than excluding the other component, unless specifically stated to the contrary.

Throughout this specification, when a member is said to be "on" another member, this includes not only the case where one member abuts another member, but also the case where another member exists between the two members.

Throughout the present specification, the unit “parts by weight” may mean a ratio of weight between each component.

Throughout this specification, "(meth) acrylate" is used to mean acrylate and methacrylate collectively.

Throughout this specification, the term "aliphatic functional group" may mean a functional group comprising a hydrocarbon which is bound in a chain and / or branch form.

Throughout the present specification, the term "alicyclic functional group" may mean a functional group including a cyclically bonded hydrocarbon, and specifically includes a carbon ring structure in which there is no unsaturated bond in the functional group, and a monocyclic ring (monocyclic ring). ) Or a polycyclic ring.

In the present specification, the glass transition temperature (Tg) is measured by heating at a heating rate of 5 ° C./min in a temperature range of −20 ° C. to 150 ° C. using a DSC (Differential Scanning Calorimeter, DSC-STAR3, METTLER TOLEDO). It may be a value determined by the midpoint of one DSC curve.

Throughout the present specification, "weight average molecular weight" may be a conversion value for polystyrene measured by GPC (Gel Permeation Chromatography).

Throughout the present specification, the modulus (Young's Modulus) is fixed to both ends of a sample prepared according to JIS-K6251-1 standard, and then a force is applied in a direction perpendicular to the thickness direction of the sample according to the tensile rate (strain). Refers to the value obtained by measuring the stress per unit area. At this time, DMA (dynamic mechanical analysis) may be used as the measuring device.

The present inventors have discovered a method capable of forming a polarizer protective film on a polarizer through a simple method of applying and curing a photocurable composition on the polarizer, and implement a polarizer protective film with excellent adhesion to the polarizer, durability, etc. The composition of the photocurable composition that can be found was found, and a photocurable composition for a polarizer protective film as described below and a polarizing film were developed using the same.

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

One embodiment of the present invention is a monomer mixture containing an alicyclic functional group-containing (meth) acrylate monomer, an aliphatic functional group-containing (meth) acrylate monomer, a polar functional group-containing (meth) acrylate monomer, and an aliphatic functional group-containing acrylamide monomer. Derived polymers; And it includes a curing agent, the glass transition temperature of the polymer is 50 ℃ to 65 ℃ to provide a photocurable composition for a polarizer protective film.

The photocurable composition for a polarizer protective film according to an exemplary embodiment of the present invention may implement a polarizer protective film having excellent durability. In addition, the photocurable composition for a polarizer protective film may provide a polarizer protective film having excellent adhesion to a polarizer.

According to an exemplary embodiment of the present invention, the polymer includes an alicyclic functional group-containing (meth) acrylate monomer, an aliphatic functional group-containing (meth) acrylate monomer, a polar functional group-containing (meth) acrylate monomer, and an aliphatic functional group-containing acrylamide monomer. It may be derived from a containing monomer mixture. Specifically, the polymerization reaction between the alicyclic functional group-containing (meth) acrylate monomer, aliphatic functional group-containing (meth) acrylate monomer, polar functional group-containing (meth) acrylate monomer, and aliphatic functional group-containing acrylamide monomer included in the monomer mixture Through, the polymer can be formed. The formed polymer may be in a liquid form containing solid content.

According to an exemplary embodiment of the present invention, the glass transition temperature (Tg) of the polymer may be 50 ° C or more and 65 ° C or less. Specifically, the glass transition temperature of the polymer is 52.5 ° C or more and 62.5 ° C or less, 55 ° C or more and 60 ° C or less, 57 ° C or more and 59 ° C or less, 50 ° C or more, 55 ° C or less, 55.5 ° C or more, 60 ° C or less, or 60.5 ° C or more and 64.5 ° C or more ℃ or less.

According to an exemplary embodiment of the present invention, by controlling the glass transition temperature of the polymer to the above-described range, it is possible to manufacture a polarizer protective film excellent in durability. Specifically, the polarizer protective film formed from the photocurable composition comprising a polymer having a glass transition temperature in the above-described range may have an appropriate modulus. In addition, the polarizer protective film formed from the photocurable composition containing the polymer may be excellent in durability under high temperature and high humidity conditions. In addition, the polarizer protective film formed from the photocurable composition containing the polymer may have excellent adhesion to the polarizer.

When the glass transition temperature of the polymer is less than 50 ° C, the polarizer protective film formed from the photocurable composition containing the polymer may have a problem of reduced durability in high temperature and high humidity conditions, and the polarizer of the polarizer protective film There may be a problem in that adhesion to the product is reduced. In addition, when the glass transition temperature of the polymer exceeds 65 ° C., the modulus of the polarizer protective film formed from the photocurable composition containing the polymer becomes excessively large, and when an external force is applied to the polarizer protective film, the polarizer protective film is easily Problems that may break or break may occur.

Therefore, according to an exemplary embodiment of the present invention, by controlling the glass transition temperature of the polymer contained in the photocurable composition for the polarizer protective film to the above-described range, has a suitable modulus, excellent polarizer with high temperature and high humidity conditions durability A protective film can be produced.

According to one embodiment of the present invention, the glass transition temperature of the polymer is DSC (Differential Scanning Calorimeter, DSC-STAR3, METTLER TOLEDO company) using the polymer in the temperature range of -20 ℃ to 150 ℃ heating rate 5 / It may be a value determined by heating to min and determined as the midpoint of the DSC curve. Specifically, when the polymer is a liquid containing a solid content, the polymer is dried to form a solid state, and the glass transition temperature of the polymer can be measured using the above-described method for the solid polymer.

According to an exemplary embodiment of the present invention, the alicyclic functional group-containing (meth) acrylate monomer may include a cycloalkyl group-containing (meth) acrylate monomer. Specifically, the cycloalkyl group-containing (meth) acrylate monomer may be a cycloalkyl group bonded to the (meth) acrylate monomer. The cycloalkyl group may include a single ring or a polycyclic ring having 3 to 20 carbon atoms, there may be no unsaturated bond in the cycloalkyl group.

According to an exemplary embodiment of the present invention, the cycloalkyl group-containing (meth) acrylate monomer is cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, trimethylcyclohexyl (meth) acrylate, and isobornyl (meth) ) May include at least one of acrylates.

According to an exemplary embodiment of the present invention, the content of the alicyclic functional group-containing (meth) acrylate monomer may be 75.5 parts by weight or more and 83.5 parts by weight or less based on 100 parts by weight of the monomer mixture. That is, in 100 parts by weight of the monomer mixture, the alicyclic functional group-containing (meth) acrylate monomer may be included in an amount of 75.5 parts by weight or more and 83.5 parts by weight or less. Specifically, the content of the alicyclic functional group-containing (meth) acrylate monomer contained in the monomer mixture is 77 parts by weight or more and 82 parts by weight or less, 79 parts by weight or more, 81 parts by weight or less based on 100 parts by weight of the monomer mixture, It may be 76 parts by weight or more and 78.5 parts by weight or less, or 80 parts by weight or more and 81.5 parts by weight or less. By adjusting the content of the alicyclic functional group-containing (meth) acrylate monomer included in the monomer mixture to the above-described range, the glass transition temperature of the polymer can be controlled within the above-described range. Through this, the modulus of the polarizer protective film formed from the photocurable composition containing the polymer can be adjusted to an appropriate range. In addition, the adhesion of the polarizer protective film to the polarizer can be improved.

By adjusting the content of the alicyclic functional group-containing (meth) acrylate monomer included in the monomer mixture to the above-described range, a polymer having a glass transition temperature of 50 ° C or more and 65 ° C or less can be prepared, and a polarizer of the polarizer protective film It can be prevented that the adhesion to the. In addition, the polarizer protective film can be easily suppressed from being broken or damaged by external force.

According to an exemplary embodiment of the present invention, the aliphatic functional group-containing (meth) acrylate monomer may include an alkyl group-containing (meth) acrylate monomer. Specifically, the alkyl group-containing (meth) acrylate monomer may be one in which an alkyl group is bound to the (meth) acrylate monomer. The alkyl group may be a hydrocarbon having 1 to 20 carbon atoms and a chain and / or branch.

According to an exemplary embodiment of the present invention, the alkyl group-containing (meth) acrylate monomer is methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, t-butyl (meth) acrylate, sec-butyl (meth) acrylate, pentyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, 2-ethylbutyl (meth) ) Acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate.

According to an exemplary embodiment of the present invention, the content of the aliphatic functional group-containing (meth) acrylate monomer may be 1.5 parts by weight or more and 9.5 parts by weight or less based on 100 parts by weight of the monomer mixture. That is, among 100 parts by weight of the monomer mixture, the aliphatic functional group-containing (meth) acrylate monomer may be included in an amount of 1.5 parts by weight or more and 9.5 parts by weight or less. Specifically, the content of the aliphatic functional group-containing (meth) acrylate monomer contained in the monomer mixture is 3 parts by weight or more and 8 parts by weight or less, 4.5 parts by weight or more, 6 parts by weight or less, 2 based on 100 parts by weight of the monomer mixture It may be 5 parts by weight or more, or 5.5 parts by weight or more and 9 parts by weight or less. By adjusting the content of the aliphatic functional group-containing (meth) acrylate monomer contained in the monomer mixture to the above-described range, the glass transition temperature of the polymer can be controlled within the above-described range. Through this, it is possible to improve the durability of the polarizer protective film formed from a photocurable composition containing the polymer. Specifically, the polarizer protective film formed from the photocurable composition for the polarizer protective film may have excellent durability even under high temperature and high humidity conditions. In addition, by adjusting the content of the aliphatic functional group-containing (meth) acrylate monomer to the above-described range, the modulus of the polarizer protective film can be appropriately controlled, and the adhesion of the polarizer protective film to the polarizer can be improved. have.

By adjusting the content of the aliphatic functional group-containing (meth) acrylate monomer contained in the monomer mixture to the above-described range, a polymer having a glass transition temperature of 50 ° C or higher and 65 ° C or lower can be prepared. In addition, by preventing the dye from dyeing from the polarizer provided with the polarizer protective film to the polarizer protective film, the polarizer protective film can effectively protect the polarizer.

According to an exemplary embodiment of the present invention, the polar functional group-containing (meth) acrylate monomer is at least one of a hydroxy group-containing (meth) acrylate monomer, a carboxyl group-containing (meth) acrylate monomer, and a nitrogen-containing (meth) acrylate monomer. It may be a monomer. The photocurable composition comprising a polymer derived from a monomer mixture containing a (meth) acrylate monomer containing a polar functional group described above can effectively improve the adhesion of the polarizer protective film to the polarizer.

According to an exemplary embodiment of the present invention, the hydroxy group-containing (meth) acrylate monomer is 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylic At least one of acrylate, 6-hydroxyhexyl (meth) acrylate, 8-hydroxyoctyl (meth) acrylate, 2-hydroxyethylene glycol (meth) acrylate and 2-hydroxypropylene glycol (meth) acrylate It may include.

According to an exemplary embodiment of the present invention, the carboxyl group-containing (meth) acrylate monomer is acrylic acid, methacrylic acid, 2-carboxyethyl acrylic acid, 3-carboxypropyl acrylic acid, 2- (meth) acryloyloxy acetic acid, 3 -(Meth) acryloyloxy propyl acid, 4- (meth) acryloyloxy butyric acid, and acrylic acid.

According to an exemplary embodiment of the present invention, the nitrogen-containing (meth) acrylate monomer is 2-isocyanatoethyl (meth) acrylate, 3-isocyanatopropyl (meth) acrylate, 4-isocyane It may include at least one of isobutyl (meth) acrylate and (meth) acrylamide.

According to an exemplary embodiment of the present invention, the content of the polar functional group-containing (meth) acrylate monomer may be 5 parts by weight or more and 15 parts by weight or less based on 100 parts by weight of the monomer mixture. That is, in 100 parts by weight of the monomer mixture, the polar functional group-containing (meth) acrylate monomer may be included in an amount of 5 parts by weight or more and 15 parts by weight or less. Specifically, the content of the polar functional group-containing (meth) acrylate monomer contained in the monomer mixture is 7 parts by weight or more and 13 parts by weight or less based on 100 parts by weight of the monomer mixture, 9 parts by weight or more, 11 parts by weight or less, 6 It may be at least 8 parts by weight, at least 8 parts by weight, at least 12 parts by weight, or at least 14.5 parts by weight. By adjusting the content of the polar functional group-containing (meth) acrylate monomer included in the monomer mixture to the above-described range, it is possible to provide a photocurable composition capable of realizing a polarizer protective film having excellent durability in high temperature and high humidity conditions. Specifically, the photocurable composition for a polarizer protective film comprising a polymer derived from the monomer mixture, the deformation is suppressed at high temperature and high humidity conditions, it is possible to provide a polarizer protective film that maintains excellent adhesion to the polarizer .

According to an exemplary embodiment of the present invention, the aliphatic functional group-containing acrylamide monomer may contain chained and / or branched alkyl groups having 1 to 4 carbon atoms. The acrylamide containing the alkyl group can be easily polymerized with the alicyclic functional group-containing (meth) acrylate monomer, aliphatic functional group-containing (meth) acrylate monomer, and polar functional group-containing (meth) acrylate monomer to obtain the polymer. Can form.

Specifically, the aliphatic functional group-containing acrylamide monomer includes at least one of dimethyl acrylamide, methylethyl acrylamide, diethyl acrylamide, ethylpropyl acrylamide, dipropyl acrylamide, butylpropyl acrylamide and dibutyl acrylamide can do.

According to an exemplary embodiment of the present invention, the content of the acrylamide monomer containing an aliphatic functional group may be 1 part by weight or more and 10 parts by weight or less based on 100 parts by weight of the monomer mixture. That is, in 100 parts by weight of the monomer mixture, the aliphatic functional group-containing acrylamide monomer may be included in an amount of 1 part by weight or more and 10 parts by weight or less. Specifically, the content of the aliphatic functional group-containing acrylamide monomer contained in the monomer mixture is 2.5 parts by weight or more and 8 parts by weight or less, 4 parts by weight or more, 6 parts by weight or less, 2 parts by weight or more based on 100 parts by weight of the monomer mixture It may be 4.5 parts by weight or less, 5 parts by weight or more and 7.5 parts by weight or less, or 8 parts by weight or more and 9.5 parts by weight or less. By adjusting the content of the acrylamide monomer containing the aliphatic functional group included in the monomer mixture to the above-described range, a photocurable composition for a polarizer protective film capable of realizing a polarizer protective film having excellent adhesion to a polarizer can be prepared.

According to an exemplary embodiment of the present invention, the weight average molecular weight of the polymer may be 200,000 g / mol or more and 3,000,000 g / mol or less. Specifically, the weight average molecular weight of the polymer is 500,000 g / mol or more and 2,500,000 g / mol or less, 1,000,000 g / mol or more, 2,000,000 g / mol or less, 1,300,000 g / mol or more, 1,800,000 g / mol or less, 300,000 g / mol or more, 600,000 g / mol or less, 800,000 g / mol or more, 1,200,000 g / mol or less, 1,500,000 g / mol or more, 2,000,000 g / mol or less, or 2,200,000 g / mol or more, 2,800,000 g / mol or less. The polarizer protective film formed from the photocurable composition comprising the polymer having a weight average molecular weight in the above-described range may have excellent durability. Specifically, the weight average molecular weight of the polymer may be a conversion value for polystyrene measured by GPC (Gel Permeation Chromatography). More specifically, when the polymer is a liquid containing a solid content, the polymer is dried to form a solid form, and the weight average molecular weight of the polymer can be measured using the above-described method for the solid polymer.

According to an exemplary embodiment of the present invention, the polymer may be formed by photocuring and / or thermosetting the monomer mixture. That is, the polymer may be a photopolymer, a thermopolymer, or a dual polymer of photopolymerization and thermal polymerization. Specifically, a curing agent may be added to the monomer mixture, and monomers included in the monomer mixture may be reacted to form a polymer. As the curing agent, a curing agent capable of thermally curing the monomers included in the monomer mixture or a curing agent capable of photocuring may be used without limitation.

For example, with respect to 100 weight of the monomer mixture, 2,2'-azo-bisisobutyrylnitrile (AIBN), which is a thermal initiator, is added and mixed by adding 0.1 part by weight or more and 1 part by weight or less, and at a temperature of 50 ° C or higher and 120 ° C or lower, The polymer can be prepared by polymerizing for 30 minutes or more and 180 minutes or less. In addition, with respect to 100 weight of the monomer mixture, after adding and mixing 0.1 part by weight or more and 1 part by weight or less of Irgacure651, a photocuring agent, UV having one wavelength value of 300 nm or more and 380 nm or less is 100 mJ / The polymer may be prepared by irradiating with a light amount of cm ² to 1,000 mJ / cm ^{2 for} a time of 5 minutes or more and 30 minutes or less.

According to an exemplary embodiment of the present invention, the photocurable composition for a polarizer protective film may include a curing agent. Specifically, the photocurable composition for the polarizer protective film may include a photocuring agent.

According to an exemplary embodiment of the present invention, the content of the curing agent may be 0.1 parts by weight or more and 5 parts by weight or less with respect to 100 parts by weight of the polymer. Specifically, the photocurable composition for a polarizer protective film may include the polymer and a curing agent, and the content of the curing agent is 0.3 parts by weight or more, 3 parts by weight or less, or 0.5 parts by weight or more based on 100 parts by weight of the polymer. It may be less than parts by weight. By adjusting the content of the curing agent included in the photocurable composition for a polarizer protective film to the above-described range, a photocuring reaction of the photocurable composition for a polarizer protective film can be more stably performed.

The photocurable composition for a polarizer protective film may further include an additive further comprising at least one of a photoinitiator and an antistatic agent. Specifically, the photocurable composition for the polarizer protective film may include the polymer, a curing agent and an additive photoinitiator. More specifically, the photocurable composition for a polarizer protective film may include the polymer, a curing agent and a photoinitiator and an antistatic agent as a participant. In addition, the additives included in the photocurable composition for the polarizer protective film may include materials used as additives in the art in addition to the photoinitiator and antistatic agent.

The photocurable composition for a polarizer protective film can be photocured to prepare a polarizer protective film comprising a cured product of the photocurable composition. That is, the polarizer protective film may be formed on one surface of the polarizer by coating and curing the photocurable composition for the polarizer protective film on one surface of the polarizer.

According to an exemplary embodiment of the present invention, the photocurable composition for a polarizer protective film may further include a photoinitiator as an additive, and the content of the photoinitiator may be 0.1 parts by weight or more and 2 parts by weight or less based on 100 parts by weight of the polymer. have. Specifically, the content of the photoinitiator may be 0.2 parts by weight or more and 1 part by weight or less, or 0.3 parts by weight or more and 0.5 parts by weight or less based on 100 parts by weight of the polymer. By adjusting the content of the photoinitiator included in the photocurable composition for a polarizer protective film to the above-described range, it is possible to effectively induce a photocuring reaction of the photocurable composition for a polarizer protective film.

According to an exemplary embodiment of the present invention, the curing agent may be a photocuring agent. Materials known as the curing agent may be used, and there is no limitation as long as it is a photocuring agent capable of photocuring the photocurable composition for the polarizer protective film. For example, the photocuring agent may include at least one of n-hexyl diacrylate, n-nonanediacrylate, and polycarbonate diacrylate, but is not limited to the type of the photocuring agent.

In addition, a material known as the photoinitiator may be used, and the photocurable composition for the polarizer protective film is not limited as long as it is a material capable of inducing a photocuring reaction. For example, the photoinitiator is 1-hydroxy-cyclohexyl-phenyl-ketone (1-Hydroxy-cyclohexyl-phenyl-ketone), 2-hydroxy-2-methyl-1-phenyl-1-propanone (2-Hydroxy -2-methyl-1-phenyl-1-propanone), 2-hydroxy-1- [4- (2-hydroxyethoxy) phenyl] -2-methyl-1-propanone (2-Hydroxy-1- [4- (2-hydroxyethoxy) phenyl] -2-methyl-1-propanone), methylbenzoylformate, oxy-phenyl-acetic acid-2- [2-oxo-2-phenyl-acetoxy-ethoxy ] -Ethyl ester (oxy-phenyl-aceticacid-2- [2-oxo-2-phenyl-acetoxy-ethoxy] -ethylester), oxy-phenyl-acetic acid-2- [2-hydroxy-ethoxy] -ethyl ester (oxy-phenyl-aceticacid-2- [2-hydroxy-ethoxy] -ethylester), alpha-dimethoxy-alpha-phenylacetophenone, 2-benzyl-2- (dimethylamino) 1- [4- (4-morpholinyl) phenyl] -1-butanone (2-Benzyl-2- (dimethylamino) -1- [4- (4-morpholinyl) phenyl] -1-butanone), 2- Methyl-1- [4- (methylthio) phenyl] -2- (4-morpholinyl) -1- Ropanone (2-Methyl-1- [4- (methylthio) phenyl] -2- (4-morpholinyl) -1-propanone), diphenyl (2,4,6-trimethylbenzoyl) -phosphine oxide (Diphenyl ( 2,4,6-trimethylbenzoyl) -phosphine oxide, phosphine oxide and phenylbis (2,4,6-trimethylbenzoyl) -phosphine oxide (phenylbis (2,4,6-trimethylbenzoyl) -phosphineoxide ).

According to an exemplary embodiment of the present invention, the photocurable composition for a polarizer protective film may further include an antistatic agent as an additive. By adding an antistatic agent to the photocurable composition for a polarizer protective film, static electricity is prevented from being generated in the polarizer protective film, so that the polarizer can be more effectively protected.

The content of the additive may be 1 part by weight or more and 10 parts by weight or less with respect to 100 parts by weight of the polymer.

According to an exemplary embodiment of the present invention, the photocurable composition for a polarizer protective film may be a solvent-free photocurable composition. That is, the photocurable composition for the polarizer protective film may not contain a solvent. Specifically, the photocurable composition for the polarizer protective film is a solvent-free type, and after applying the photocurable composition for the polarizer protective film on one surface of the polarizer, the photocurable composition for the polarizer protective film without a drying process for removing the solvent By photocuring, a polarizer protective film may be formed on one surface of the polarizer.

Therefore, according to an exemplary embodiment of the present invention, by using a photocurable composition for a solvent-free polarizer protective film, it is possible to further simplify the manufacturing process of the polarizing film including the polarizer and the polarizer protective film, and improve the manufacturing efficiency of the polarizing film. Can be improved.

Another embodiment of the present invention provides a polarizer protective film comprising a cured product of the photocurable composition for the polarizer protective film.

The polarizer protective film according to an exemplary embodiment of the present invention may be excellent in adhesion and durability to the polarizer by including a cured product of the photocurable composition for the polarizer protective film.

Another embodiment of the present invention provides a polarizing film.

An exemplary embodiment of the present invention is a polarizer; And a polarizer protective film including a cured product of the photocurable composition for the polarizer protective film provided on at least one surface of the polarizer.

According to an exemplary embodiment of the present invention, the polarizer protective film may be directly provided on at least one surface of the polarizer by applying and curing the photocurable composition for the polarizer protective film on at least one surface of the polarizer.

According to an exemplary embodiment of the present invention, a configuration known as the polarizer may be used, and there is no limitation as long as it is a configuration capable of imparting polarization characteristics to the polarizing film. As an example, a polyvinyl alcohol (PVA) -based polarizer may be used as the polarizer. Specifically, iodine (I ₂ ) or a dichroic dye or the like is adsorbed as the polarizer, and a polyvinyl alcohol polarizer that has been crosslinked or stretched may be used.

According to an exemplary embodiment of the present invention, the polarizer protective film may be formed on one or both surfaces of the polarizer. The thickness of the polarizer protective film provided on at least one surface of the polarizer may be 4 μm or more and 100 μm or less. The polarizer protective film having the above-described thickness range may have excellent durability, and may further thin the polarizing film. In addition, the thickness of the polarizer included in the polarizing film may be 10 μm or more and 60 μm or less.

According to an exemplary embodiment of the present invention, the modulus of the polarizer protective film may be 1,000 MPa or more and 10,000 MPa or less. Specifically, in accordance with JIS-K6251-1, the modulus of the polarizer protective film measured in an atmosphere of 35 ° C. and 50 RH% may be 1,000 MPa or more and 10,000 MPa or less. In addition, the modulus of the polarizer protective film is 2,000 MPa or more, 8,000 MPa or less, 4,000 MPa or more, 7,000 MPa or less, 5,000 MPa or more, 6,000 MPa or less, 1,500 MPa or more, 3,000 MPa or less, 3,500 MPa or more, 5,000 MPa or less, or 7,000 MPa or more and 9,000 MPa or more It may be: The polarizer protective film having a modulus in the above-described range may have excellent durability. In addition, even when an external force is applied to the polarizing film, such as bending of the polarizing film, the polarizer protective film can easily maintain a state attached to the polarizer.

According to an exemplary embodiment of the present invention, the photocurable composition for a polarizer protective film is coated on one surface of a release film and cured to form a polarizer protective film having a thickness of 40 μm on one surface of the release film. Thereafter, the polarizer protective film is peeled on one surface of the release film, and the peeled polarizer protective film can be cut to a size of 3 cm in width and 1 cm in length to prepare a sample. Thereafter, after fixing both ends of the prepared sample, according to JIS-K6251-1, using DMA (Dynamic mechanical analysis), a force is applied in a direction perpendicular to the thickness direction of the sample, and the unit according to the strain rate (strain) By measuring the stress per area, the modulus of the polarizer protective film can be measured.

According to an exemplary embodiment of the present invention, the glass transition temperature of the polarizer protective film may be 50 ℃ or more and 65 ℃ or less. That is, the glass transition temperature of the polarizer protective film may be substantially the same as the glass transition temperature of the polymer contained in the photocurable composition for the polarizer protective film. The glass transition temperature of the polarizer protective film and the glass transition temperature of the polymer are substantially the same, when the glass transition temperature of the polarizer protective film and the glass transition temperature of the polymer are the same, for the polarizer protective film containing the polymer By the process of curing the photo-curable composition, it may mean that the glass transition temperature of the polarizer protective film and the glass transition temperature of the polymer are slightly different.

Another embodiment of the present invention provides a method of manufacturing a polarizing film.

One embodiment of the present invention comprises the steps of preparing a polarizer; Applying a photocurable composition for a polarizer protective film on one surface of the polarizer; And curing the light-curable composition for the polarizer protective film; provides a method for producing a polarizing film comprising a.

According to an exemplary embodiment of the present invention, a polarizing film including a polarizer protective film having excellent durability can be easily manufactured. In addition, the polarizer protective film may have excellent adhesion to the polarizer. In addition, the polarizer protective film may have excellent durability under high temperature and high humidity conditions.

According to an exemplary embodiment of the present invention, the polarizer protective film may be directly provided on one surface of the polarizer through a simple process of applying and curing the photocurable composition for the polarizer protective film on one surface of the polarizer.

According to an exemplary embodiment of the present invention, the step of preparing the polarizer may be prepared by using a known method, and if the method of manufacturing a polarizer capable of imparting polarization characteristics to the polarizing film is limited. none. For example, a polyvinyl alcohol-based polarizer may be prepared by performing steps such as dyeing, cross-linking, stretching, washing, complementary color, and drying the polyvinyl alcohol-based film.

According to an exemplary embodiment of the present invention, the step of applying the photocurable composition for a polarizer protective film may apply the photocurable composition for a polarizer protective film to a thickness of 4 μm or more and 100 μm or less on one surface of the polarizer. . Thereafter, the photocurable composition for a polarizer protective film may be photocured to form a polarizer protective film having a thickness of 4 μm or more and 100 μm or less on one surface of the polarizer. That is, the thickness of the photocurable composition for the polarizer protective film and the thickness of the polarizer protective film may be substantially the same. The composition for the polarizer protective film is a solvent-free type, and a process of drying the composition for the polarizer protective film may be omitted, so that the thickness of the photocurable composition for the polarizer protective film and the thickness of the polarizer protective film may be substantially the same. have.

The polarizer protective film having a thickness in the above-described range may have excellent durability. Therefore, by applying the photocurable composition for a polarizer protective film on one surface of the polarizer with a thickness in the above-described range, a polarizer protective film having excellent durability can be manufactured.

In addition, by applying and curing the photocurable composition for a polarizer protective film on the other surface of the polarizer provided with a polarizer protective film on one surface, it is possible to manufacture a polarizing film comprising a polarizer with a polarizer protective film on both sides . The thickness of the polarizer protective film provided on one surface of the polarizer and the polarizer protective film provided on the other surface of the polarizer may be the same or different.

According to an exemplary embodiment of the present invention, a known process can be used as a method of applying the photocurable composition for a polarizer protective film on one surface of the polarizer. Specifically, inkjet printing process, dispensing process, silk screen process, spray coating process, spin coating process, knife coating process, dip coater coating process, Mayer bar coating process, gravure coating process, offset coating process, gravure offset coating process, A roll-to-roll offset coating process, a micro gravure coating process, or the like can be used.

According to an exemplary embodiment of the present invention, a polarizer protective film can be prepared by applying and curing the photocurable composition for a polarizer protective film on one surface of the polarizer, and the existing polarizer protective film is placed on one surface of the polarizer. Compared to the process of attaching using an adhesive or an adhesive film, it is possible to effectively improve the manufacturing efficiency of the polarizing film. In addition, the manufacturing time and manufacturing cost of the polarizing film can be effectively reduced.

According to an exemplary embodiment of the present invention, the step of curing the photocurable composition for a polarizer protective film is to irradiate black light UV to the photocurable composition for a polarizer protective film to cure the photocurable composition for a polarizer protective film. May be The photocurable composition for the polarizer protective film can be cured using the black light UV, so that the process of aging the photocurable composition for the polarizer protective film can be omitted.

Therefore, according to an exemplary embodiment of the present invention, by curing the photocurable composition for the polarizer protective film using the black light UV, the process of aging the photocurable composition for the polarizer protective film is omitted, so that the polarizer The manufacturing efficiency of the protective film can be improved, and the manufacturing time and manufacturing cost can be reduced.

According to an exemplary embodiment of the present invention, the step of curing the photocurable composition for a polarizer protective film, black light UV having any one of the wavelength value of 350 nm or more and 390 nm or less 200 J / cm ² to 800 It may be irradiated for a time of 1 minute or more and 5 minutes or less with a light amount of J / cm ² . By using black light UV having a wavelength value in the above range, the photocurable composition for a polarizer protective film can be effectively cured. In addition, by irradiating the black light UV with the amount of light in the above-described range, the curing time of the photocurable composition for the polarizer protective film can be effectively reduced. In addition, by irradiating the black light UV for a time in the above-described range, the photocurable composition for a polarizer protective film can be stably cured. That is, through the photocuring process under the above-described conditions, a polarizer protective film can be more easily formed on one surface of the polarizer.

Hereinafter, examples will be described in detail to specifically describe the present invention. However, the embodiments according to the present invention may be modified in various other forms, and the scope of the present invention is not interpreted to be limited to the embodiments described below. The embodiments of the present specification are provided to more fully describe the present invention to those skilled in the art.

Polarizer  Protective film Photocurable  Preparation of the composition

Example  One

As an alicyclic functional group-containing (meth) acrylate monomer, isobornyl acrylate (IBOA), an aliphatic functional group-containing (meth) acrylate monomer, as a monomer, butyl acrylate (BA), polar functional group-containing (meth) acrylate A monomer mixture was prepared by mixing 2-hydroxyethyl acrylate (HEA) as a monomer and dimethyl acrylamide as an acrylamide monomer containing an aliphatic functional group. Based on 100 parts by weight of the monomer mixture, the content of isobornyl acrylate is about 80 parts by weight, the content of butyl acrylate is about 5 parts by weight, the content of hydroxyethyl acrylate is about 10 parts by weight, the content of dimethyl acrylamide Was about 5 parts by weight. After adding and mixing about 0.2 parts by weight of Irgacure651 (CIVA), a photocuring agent, based on 100 parts by weight of the monomer mixture, UV having a wavelength value of 350 nm was irradiated for about 3 minutes with a light amount of 500 J / cm ² , Polymers were prepared. The glass transition temperature of the polymer prepared as above was about 58 ° C., and the weight average molecular weight was about 1,500,000 g / mol.

Irgacure651 (CIVA) as a photoinitiator, SUO-1020 (Miwon) as a photocuring agent, and FC-4400 (3M) as an antistatic agent were prepared. With respect to 100 parts by weight of the prepared polymer, about 0.2 parts by weight of a photoinitiator, about 1 part by weight of a photocuring agent and about 1.5 parts by weight of an antistatic agent were added and mixed to prepare a photocurable composition for a polarizer protective film.

Example  2

Based on 100 parts by weight of the monomer mixture, the content of isobornyl acrylate is about 81 parts by weight, the content of butyl acrylate is about 9 parts by weight, the content of hydroxyethyl acrylate is about 7 parts by weight, the content of dimethyl acrylamide A photocurable composition for a polarizer protective film was prepared in the same manner as in Example 1, except that was adjusted to about 3 parts by weight.

Comparative example  1 to Comparative example  3

A photocurable composition for a polarizer protective film was prepared in the same manner as in Example 1, except that the composition of the monomer mixture was prepared as shown in Table 1 below. In Table 1, IBOA means isobornyl acrylate, BA means butyl acrylate, DMAA means dimethyl acrylamide, and HEA means hydroxyethyl acrylate.

Monomer mixture
(Based on 100 parts by weight) Polymer
Glass transition temperature
(℃) Polymer
Weight average molecular weight
(g / mol) IBOA
(Parts by weight) BA
(Parts by weight) DMAA
(Parts by weight) HEA
(Parts by weight) Example 1 80 5 5 10 58 1,500,000 Example 2 81 9 7 3 59 1,700,000 Comparative Example 1 70 15 5 10 38 150,000 Comparative Example 2 75 10 5 10 48 190,000 Comparative Example 3 84 One 5 10 68 3,100,000

Comparative example  4

A triacetyl cellulose film (LG Chemical Co.) having a thickness of 40 μm was prepared as a polarizer protective film.

[ Experimental example ]

Polarizer  Measurement of glass transition temperature of protective film

The photocurable compositions for polarizer protective films according to Examples 1 to 2 and Comparative Examples 1 to 3 of the present invention were respectively coated with a thickness of about 40 μm on a release film (L3T, Toray Co.). Thereafter, a black light UV having a wavelength value of 350 nm was irradiated with a light intensity of 500 J / cm ² for about 3 minutes using a black light UV lamp (BL350, Sylvania, Inc.) to cure the photocurable composition for a polarizer protective film. To prepare a polarizer protective film having a thickness of about 40 μm. Thereafter, the polarizer protective film was peeled from the release film, and cut to a size of 3 cm in width and 3 cm in length to measure the glass transition temperature of the polarizer protective film. In addition, after cutting the triacetyl cellulose film prepared in Comparative Example 4 to a size of 3 cm in width and 3 cm in length, a sample was prepared, and then the glass transition temperature was measured in the same manner as described above.

Polarizer  Protective film Modulus  Measure

The photocurable compositions for polarizer protective films according to Examples 1 to 2 and Comparative Examples 1 to 3 of the present invention were respectively coated with a thickness of about 40 μm on a release film (L3T, Toray Co.). Subsequently, a black light UV having a wavelength value of 350 nm was irradiated with a light intensity of 500 J / cm ² for about 3 minutes using a black light UV lamp (BL350, Sylvania, Inc.) to obtain a 40 μm thick polarizer protective film. It was prepared. Thereafter, the polarizer protective film was peeled from the release film, and cut to a size of 3 cm in width and 1 cm in length to prepare a sample. Then, after fixing both ends of the prepared sample, in accordance with JIS-K6251-1, using DMA (Dynamic mechanical analysis, TA 社), by applying a force in the direction perpendicular to the thickness direction of the sample tensile rate (Strain) The stress per unit area according to was measured, and the modulus of the polarizer protective film was measured.

In addition, the triacetyl cellulose film prepared in Comparative Example 4 was cut to a size of 3 cm in width and 1 cm in length to prepare a sample, and modulus was measured in the same manner as described above.

Polarizer  Protection film of high temperature and high humidity Adhesion  Experiment

A polyvinyl alcohol (PVA) -based polarizer (LG Chemical Co.) having a thickness of 20 μm was prepared. Subsequently, the photocurable compositions for the polarizer protective films according to Examples 1 to 2 and Comparative Examples 1 to 3 of the present invention were respectively coated on a PVA-based polarizer with a thickness of about 40 μm. Thereafter, a black light UV having a wavelength value of 350 nm was irradiated with a light intensity of 500 J / cm ² for about 3 minutes using a black light UV lamp (BL350, Sylvania, Inc.) to cure the photocurable composition for a polarizer protective film. To prepare a polarizing film including a polarizer protective film having a thickness of about 40 μm.

Thereafter, the prepared polarizing film was cut to a size of 14 cm in width and 8 cm in length to prepare a sample, and then the sample was placed in a chamber with a temperature of 60 ° C. and a humidity of 90 RH% and left for 150 hours. Thereafter, the sample was observed with the naked eye to check whether the polarizer protective film was peeled from the polarizer, and if peeled, it was evaluated as “X”, and when not peeled, it was evaluated as “O”.

Polarizer  Protective film Bending  Experiment

The photocurable compositions for polarizer protective films according to Examples 1 to 2 and Comparative Examples 1 to 3 of the present invention were respectively coated with a thickness of about 40 μm on a release film (L3T, Toray Co.). Thereafter, a black light UV having a wavelength value of 350 nm was irradiated with a light intensity of 500 J / cm ² for 3 minutes using a black light UV lamp (BL350, Sylvania) to cure the photocurable composition for a polarizer protective film. A polarizer protective film having a thickness of about 40 μm was prepared. Thereafter, the polarizer protective film was peeled from the release film, and cut to a size of 8 cm in width and 4 cm in length to prepare a sample. In addition, the triacetyl cellulose film prepared in Comparative Example 4 was cut to a size of 8 cm in width and 4 cm in length to prepare a sample.

Then, after folding the prepared sample 180 degrees and observing the cross section with the naked eye, it was confirmed whether or not the cross section of the polarizer protective film was broken. Was evaluated.

Physical properties of the polarizer protective films according to Examples 1 to 2 and Comparative Examples 1 to 4 of the present invention according to the above-described experimental examples are shown in Table 2 below.

Glass transition temperature
(℃) Modulus
(GPa) High temperature, high humidity
Adhesion experiment Bending experiment Example 1 57.5 3300 O O Example 2 58.5 3200 O O Comparative Example 1 38.5 1500 X O Comparative Example 2 48.5 1950 X O Comparative Example 3 67 3790 O X Comparative Example 4 100 3210 - O

Referring to Table 2, it was confirmed that the polarizer protective films according to Example 1 and Example 2 of the present invention had a modulus similar to that of the triacetyl cellulose film of Comparative Example 4. That is, the polarizer protective film according to an exemplary embodiment of the present invention has a modulus similar to that of the conventional polarizer protective film, so it can be confirmed that the polarizer can be favorably protected like the conventional polarizer protective film.

In addition, referring to Table 2, it was confirmed that the polarizer protective films according to Examples 1 and 2 of the present invention did not peel off from the polarizer even under high temperature and high humidity conditions. On the other hand, it was confirmed that the polarizer protective films according to Comparative Examples 1 to 2 were peeled from the polarizer under high temperature and high humidity conditions. Accordingly, the polarizer protective film according to an exemplary embodiment of the present invention can maintain adhesion even under high temperature and high humidity conditions, and thus it can be seen that the durability for high temperature and high humidity is excellent.

In addition, referring to the results of the bending experiment in Table 2, it was confirmed that the polarizer protective films according to Examples 1 and 2 of the present invention had better durability against deformation than the polarizer protective films according to Comparative Example 3. Therefore, it can be seen that the polarizer protective film according to an exemplary embodiment of the present invention has excellent durability against mechanical deformation.

Claims (14)

Polymers derived from a monomer mixture comprising an alicyclic functional group-containing (meth) acrylate monomer, an aliphatic functional group-containing (meth) acrylate monomer, a polar functional group-containing (meth) acrylate monomer, and an aliphatic functional group-containing acrylamide monomer; And
Curing agent; and
The polymer has a glass transition temperature of 50 ° C to 65 ° C, and a photocurable composition for a polarizer protective film. The method according to claim 1,
The content of the alicyclic functional group-containing (meth) acrylate monomer is a photocurable composition for a polarizer protective film that is 75.5 parts by weight or more and 83.5 parts by weight or less based on 100 parts by weight of the monomer mixture. The method according to claim 1,
The content of the aliphatic functional group-containing (meth) acrylate monomer is a photocurable composition for a polarizer protective film that is 1.5 parts by weight or more and 9.5 parts by weight or less based on 100 parts by weight of the monomer mixture. The method according to claim 1,
The content of the polar functional group-containing (meth) acrylate monomer is 5 parts by weight or more and 15 parts by weight or less based on 100 parts by weight of the monomer mixture, a photocurable composition for a polarizer protective film. The method according to claim 1,
The content of the acrylamide monomer containing an aliphatic functional group is a photocurable composition for a polarizer protective film that is 1 part by weight or more and 10 parts by weight or less based on 100 parts by weight of the monomer mixture. The method according to claim 1,
The polymer has a weight average molecular weight of 200,000 g / mol or more and 3,000,000 g / mol or less. The photocurable composition for polarizer protective films. The method according to claim 1,
The content of the curing agent is a photocurable composition for a polarizer protective film that is 0.1 parts by weight or more and 5 parts by weight or less based on 100 parts by weight of the polymer. The method according to claim 1,
A photocurable composition for a polarizer protective film further comprising an additive comprising at least one of a photoinitiator and an antistatic agent. The method according to claim 1,
The photocurable composition for a polarizer protective film is a solvent-free photocurable composition for a polarizer protective film. Polarizer; And
A polarizer protective film comprising; a polarizer protective film comprising a cured product of the photocurable composition for a polarizer protective film according to claim 1 provided on at least one surface of the polarizer. The method according to claim 10,
The polarizer of the polarizer protective film is 1,000 MPa or more and 10,000 MPa or less. Preparing a polarizer;
Applying a photocurable composition for a polarizer protective film according to claim 1 on one surface of the polarizer; And
Curing the photocurable composition for the polarizer protective film; Method of manufacturing a polarizing film comprising a. The method according to claim 12,
The curing of the photocurable composition for the polarizer protective film may include black light UV having a wavelength value of 350 nm or more and 390 nm or less in a light amount of 200 J / cm ² to 800 J / cm ² for 1 minute or more and 5 minutes or less. A method of manufacturing a polarizing film that is irradiated for a period of time. The method according to claim 12,
The step of applying the photocurable composition for a polarizer protective film is to apply the photocurable composition for a polarizer protective film to a thickness of 4 μm or more and 100 μm or less on one surface of the polarizer.