KR20120074462A - Adhesive composition for optical use - Google Patents

Abstract

PURPOSE: An adhesive composition for optics is provided to reduce hardening shrinkage generation in free radical photopolymerization while maintaining adhesiveness and coatability. CONSTITUTION: An adhesive composition for optics comprises 30-80 weight% of urethane acrylate-based oligomer, 10-60 weight% of acrylate-based monomer, 0.1-5 weight% of aminosilane compound which is represented by chemical formula 1, and 0.1-5 weight% free radical photoinitiator. In the chemical formula 1, R1, R2, R3, R4 and R5 respectively indicate C1-4 alkyl groups. The adhesive is obtained by hardening the adhesive composition. The adhesive film comprises a transparent substrate film and an adhesive formed in one side of the transparent based film.

Description

Optical adhesive composition {ADHESIVE COMPOSITION FOR OPTICAL USE}

The present invention relates to a pressure-sensitive adhesive composition having a low thickness and hardening shrinkage during free radical photopolymerization while maintaining the physical properties of the pressure-sensitive adhesive itself and having excellent durability and curing rate such as surface appearance, heat resistance and heat and moisture resistance.

In general, a liquid crystal display device (LCD) includes a liquid crystal cell and a polarizing plate including liquid crystal, and an appropriate adhesive layer or an adhesive layer for bonding them should be used.

The pressure-sensitive adhesive layer (film) may be classified into a thin film type adhesive layer and a thick film type adhesive layer depending on the use of a solvent.

The double thick-film adhesive layer is generally produced by free radical photopolymerization of an acrylate oligomer or urethane acrylate oligomer and a composition containing a photoinitiator.

In this case, in order to improve the efficiency of photopolymerization, a public initiator such as tertiary amine or amine (meth) acrylate is used together with the photoinitiator.

However, the tertiary amine acts as an impurity by a coupling reaction with the components of the pressure-sensitive adhesive composition after photocuring, thereby lowering the durability such as heat resistance and heat and humidity resistance. In addition, since the amine (meth) acrylate reduces the equivalent of acrylic in the pressure-sensitive adhesive composition to cause hardening shrinkage, there is a problem that the thickness of the pressure-sensitive adhesive layer is uneven and the surface appearance is not good.

The present invention is to provide a pressure-sensitive adhesive composition excellent in durability and curing rate, such as uniform thickness, surface appearance, heat and moisture-resistant heat, such as less hardening shrinkage during free radical photopolymerization while maintaining the coating properties and adhesive strength of the conventional equivalent or more.

The present inventors made an effort to achieve the above object. As a result, when a specific amine silane having a lower alkyl group and a amine group having a tertiary amine group is used as the open initiator used with the free radical photoinitiator, the activity of the open initiator is high, so that the efficiency of photopolymerization is improved and the self-bonding of the silane group is achieved. The reactivity with the main component of the pressure-sensitive adhesive composition is thereby significantly reduced to prevent the degradation of durability, such as heat resistance and heat and moisture resistance, and to reduce the occurrence of hardening shrinkage has been completed the present invention.

Accordingly, the present invention comprises 30 to 80% by weight of the urethane acrylate oligomer, 10 to 60% by weight of the acrylate monomer, 0.1 to 5% by weight of the amine silane compound represented by the formula (1) and 0.1 to 5% by weight of the free radical photoinitiator Provided is an optical pressure-sensitive adhesive composition.

Wherein, R ₁ , R _2, R ₃ , R ₄ and R ₅ are each an alkyl group having 1 to 4 carbon atoms.

The acrylate monomer may be 1 to 6 functional.

R ₁ , R _2, R ₃ of the aminesilane compound, R ₄ and R ₅ may each be an alkyl group having 1 to 2 carbon atoms.

R ₄ and R ₅ of the aminesilane compound may each be a methyl group.

The composition may further include an additive of an acrylate resin syrup, a tackifier resin or a mixture thereof.

Moreover, the adhesive of this invention is what hardened | cured the said adhesive composition.

In addition, the adhesive film of the present invention is a transparent substrate film; It includes the pressure-sensitive adhesive formed on one surface of the transparent base film.

The pressure-sensitive adhesive is 25 to 1000㎛ thickness.

The pressure-sensitive adhesive composition of the present invention not only maintains coating properties and adhesive strengths equivalent to those of the related art, but also has less hardening shrinkage during photopolymerization, and thus has a uniform thickness and excellent durability such as surface appearance, heat resistance, and moisture resistance heat.

Moreover, the adhesive composition of this invention improves a hardening rate, and is easy for mass production.

In addition, since the pressure-sensitive adhesive composition of the present invention does not contain a separate solvent, it is possible to manufacture a thick-film pressure-sensitive adhesive film.

In addition, the pressure-sensitive adhesive composition of the present invention is expected to improve the adhesive strength with the glass substrate including a silane group.

The present invention relates to a pressure-sensitive adhesive composition having excellent durability such as surface appearance, heat resistance, heat and moisture resistance due to less occurrence of hardening shrinkage during free radical photopolymerization while maintaining physical properties of the pressure-sensitive adhesive itself.

Hereinafter, the present invention will be described in detail.

Optical pressure-sensitive adhesive composition of the present invention is 30 to 80% by weight urethane acrylate oligomer, 10 to 60% by weight acrylate monomer, 0.1 to 5% by weight of the amine silane compound of formula 1 and 0.1 to 5% by weight of free radical photoinitiator It includes.

[Formula 1]

Wherein, R ₁ , R _2, R ₃ , R ₄ and R ₅ are each an alkyl group having 1 to 4 carbon atoms.

The urethane acrylate oligomer comprises a reactive end group and a urethane bond group in a main chain component such as polyether, polyester, polyolefin, polyacrylate, and polycarbonate. The main chain component is preferably polyether in terms of low viscosity and low cost.

Polyethers consist primarily of polymeric diols or polyols and hydroxy acid components, and polyols suitable for use include polyether diols, hydrocarbon diols, polycarbonate diols, polyacrylate polyols (hydroxy functional acrylic polymers), polycaprolactone Diols and the like. These polyols can be used individually or in combination of 2 or more.

The method of polymerizing each structural unit of the polyol is not particularly limited, but block polymerization or graft polymerization may be used.

The polyether diol is obtained by ring-opening copolymerization of polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polyhexamethylene glycol, polyheptamethylene glycol, polydecamethylene glycol, two or more ion-polymerized cyclic compounds, and the like. Can lose.

The ion-polymerized cyclic compound may be, for example, ethylene oxide, propylene oxide, butene-1-oxide, isobutene oxide, 3,3'-bischloromethyloxetane, tetrahydrofuran, 2-methyltetrahydrofuran, 3-methyltetrahydrofuran, dioxane, trioxane, tetraoxane, cyclohexene oxide, styrene oxide, epichlorohydrin, glycidyl methacrylate, allyl glycidyl ether, allyl glycidyl carbonate, butadiene monoxide Cyclic ethers such as isoprene monoxide, vinyl oxetane, vinyltetrahydrofuran, vinyl cyclohexene oxide, phenyl glycidyl ether, butyl glycidyl ether and glycidylbenzoate and the like.

Specific examples of the polyether diol obtained by ring-opening copolymerization of two or more forms of such ion-polymerized cyclic compounds include tetrahydrofuran and propylene oxide; Tetrahydrofuran and 2-methyltetrahydrofuran; Tetrahydrofuran and 3-methyltetrahydrofuran; Tetrahydrofuran and ethylene oxide; Propylene oxide and ethylene oxide; And copolymers obtained by the combination of ethylene oxide and butene-1-oxide, tertiary copolymers obtained by the combination of tetrahydrofuran, ethylene oxide and butene-1-oxide.

In addition, one of the ion-copolymerized cyclic compounds described above and cyclic imines such as ethylene imine; cyclic lactones such as β-propiolactone and glycolic acid lactide; Or polyether diol obtained by ring-opening copolymerization of dimethylcyclopolysiloxane can also be used. The ring-opening copolymer of such ion-polymerized cyclic compounds may be random copolymers or block copolymers.

Such urethane acrylate oligomer contains 30 to 80% by weight, preferably 40 to 70% by weight, based on the total amount of the pressure-sensitive adhesive composition (100% by weight), when the content is less than 30% or more than 80% by weight. The problem may occur that the durability is lowered.

The acrylate-based monomers impart durability to the film including the pressure-sensitive adhesive composition and maintain viscoelasticity, and serve to improve the coatability of the composition by controlling the viscosity.

As the acrylate monomer, 1 to 6 functional acrylic monomers may be used, and specific examples thereof include ethyl acrylate, methyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, butyl acrylate and isobutyl acrylate. , Allyl methacrylate, 2-ethoxyethyl (meth) acrylate, isodecyl (meth) acrylate, 2-dodecylthioethyl methacrylate, octyl acrylate, isooctyl acrylate, 2-methoxyethyl acryl Rate, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, isooctyl (meth) acrylate, isodecyl (meth) acrylate, stearyl (meth) Acrylate, tetraperfuryl (meth) acrylate, phenoxyethyl (meth) acrylate, octadecyl methacrylate, isobornyl (meth) acrylate, tetrahydrofuryl a A monofunctional monomer such as a relay agent, one know acryloyl morpholine; 1,3-butanedioldi (meth) acrylate, 1,4-butanedioldi (meth) acrylate, 1,6-hexanedioldi (meth) acrylate, ethylene glycoldi (meth) acrylate, bisphenol A-ethylene Glycol diacrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, dipropylene glycol di (meth) Acrylate, tripropylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, dicyclopentanyldi (meth) acrylate, caprolactone modified dicyclopentenyldi (meth) acrylate, ethylene oxide modified phosphoric acid Di (meth) acrylate, bis (2-hydroxyethyl) isocyanurate di (meth) acrylate, di (acryloxyethyl) isocyanurate, allylated cyclohexyldi (meth) acrylate Difunctional monomers such as hydrate, dimethylol dicyclopentanediacrylate, ethylene oxide modified hexahydrophthalic acid diacrylate, tricyclodecane dimethanol acrylate, neopentyl glycol modified trimethylolpropane diacrylate, adamantane diacrylate ; Trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, propionic acid modified dipentaerythritol tri (meth) acrylate, propylene oxide modified trimethylolpropane Trifunctional monomers such as tri (meth) acrylate, tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate, tris (acryloxyethyl) isocyanurate, and glycerol tri (meth) acrylate ; Tetrafunctional monomers such as diglycerin tetra (meth) acrylate, pentaerythritol tetra (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate; Pentafunctional monomers such as propionic acid-modified dipentaerythritol penta (meth) acrylate; Six functional monomers, such as dipentaerythritol hexa (meth) acrylate and caprolactone modified dipentaerythritol hexa (meth) acrylate, etc. are mentioned, These can be used individually or in mixture of 2 or more types.

The acrylate monomer is 10 to 60% by weight, preferably 20 to 50% by weight relative to the total content (100% by weight) of the pressure-sensitive adhesive composition. If the content is less than 10% by weight, the curing rate is low, or the storage modulus is too low, there is a fear that the cohesive failure occurs, if it exceeds 60% by weight hardening shrinkage may be a problem in coating properties.

The aminesilane compound of Formula 1 is used together with a free radical photoinitiator to serve to promote the reaction of the pressure-sensitive adhesive composition.

The conventionally used open initiators such as tertiary amines and amine acrylates act as impurities by binding reactions with the constituents of the pressure-sensitive adhesive composition, thereby lowering durability or reducing the equivalent amount of acrylic in the composition, thereby causing a hardening shrinkage phenomenon.

The aminesilane compound of the present invention has a silane group having a lower alkyl group and a tertiary amine group, and the self-bonding of the silane groups significantly reduces the reactivity with the main component of the pressure-sensitive adhesive composition and increases the activity by the tertiary amine groups, thereby improving photopolymerization efficiency. Can be.

In addition, the silane group may have an excellent bonding force with glass, thereby improving adhesion to a glass substrate such as a liquid crystal panel.

R ₁ , R _2, R ₃ of Formula 1, R ₄ and R ₅ are each preferably an alkyl group having 1 to 4 carbon atoms and preferably an alkyl group having 1 to 2 in consideration of the activity of the photopolymerization reaction. In particular, R ₄ and R ₅ are each preferably a methyl group.

The aminesilane compound contains 0.1 to 10% by weight, preferably 0.1 to 5% by weight, based on the total amount of the pressure-sensitive adhesive composition (100% by weight), and when the content exceeds 10% by weight, excessive silane polymerization may occur. Problems with compatibility may occur.

The free radical photoinitiator plays a role of sufficiently advancing the internal and surface hardening of the pressure-sensitive adhesive, and the type is not particularly limited as long as it is known in the art.

Specific examples of the free radical photoinitiator include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, acetophenone, hydroxydimethylacetophenone, Dimethylaminoacetophenone, dimethoxy-2-phenylacetophenone, 3-methylacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 4-chronolo Cetophenone, 4,4-dimethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 4-hydroxycyclophenylketone, 1-hydroxycyclohexylphenylketone, 2-methyl -1- [4- (methylthio) phenyl] -2-morpholino-propane-1-one, 4- (2-hydroxyethoxy) phenyl-2- (hydroxy-2-propyl) ketone, benzo Phenone, p-phenylbenzophenone, 4,4-diaminobenzophenone, 4,4'-diethylaminobenzophenone, dichlorobenzophenone, anthraquinone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-t -Butyl anthra Paddy, 2-aminoanthraquinone, 2-methyl thioxanthone, 2-ethyl thioxanthone, 2-chlorothioxanthone, 2,4-dimethyl thioxanthone, 2,4-diethyl thioxanthone, benzyldimethyl Ketal, diphenyl ketone benzyl dimethyl ketal, acetophenone dimethyl ketal, p-dimethylaminobenzoic acid ester, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, fluorene, triphenylamine, carbazole and the like. have. Moreover, as a commercially available product, brand names Darocur 1173, Igacure 184, Igacure 907, Igacure-1700 (Ciba company), etc. can also be used. These can be used individually or in combination of 2 or more types.

The free radical photoinitiator may be used in an appropriate range in consideration of the emission characteristics, the intensity of the light source, the content of each component, etc., 0.1 to 5% by weight, preferably 0.1 to 3 to the total content of the pressure-sensitive adhesive composition (100% by weight) It is preferable to contain by weight%.

In addition, the pressure-sensitive adhesive composition of the present invention may further include additives such as acrylate resin syrup, tackifying resin or a mixture thereof.

The tackifier resin is used for viscosity control at the same time to improve the adhesive force, for example rosin ester, synthetic hydrocarbons and the like can be used. Preferred as the rosin ester is a Poral 85LB product (ring and ball softening point (ASTM E 28) 65 ° C.) sold by Eastman Chemicals, The Netherlands.

The acrylate resin syrup is a resin syrup in which an acrylic monomer and a polyacrylate, which is a polymer thereof, are dissolved. The acrylate resin syrup serves to exhibit an easy storage modulus in the handling and adhesion process of the adhesive film.

The acrylic monomers include acrylic acid, methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, 2-ethyl hexyl acrylate, isobornyl acrylate, and the like.

The polyacrylate is a polymer such as methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, 2-ethyl hexyl acrylate, and most preferably, 2-ethyl hexyl acrylate (2-EHA). .

Such additives may be appropriately adjusted and contained within a range not departing from the intended effect range of the pressure-sensitive adhesive composition according to the present invention, and preferably contained at 30% by weight or less relative to the total content of the pressure-sensitive adhesive composition (100% by weight). .

The adhesive composition of the present invention can be cured to form an adhesive. In addition, transparent substrate film; An adhesive film may be formed by including the adhesive formed on one surface of the transparent base film.

The pressure-sensitive adhesive may have a thickness of 25 to 1000㎛.

The transparent base film is not particularly limited as it is excellent in transparency, mechanical strength, thermal stability, moisture barrier property, isotropy and the like.

The curing is used in the art, but is not particularly limited, photocuring using ultraviolet light is generally.

In the polymerization using ultraviolet rays, the light source has a light emission distribution having a wavelength of 400 nm or less, preferably 150 to 400 nm, more preferably 200 to 380 nm. For example, low pressure mercury lamp, medium pressure mercury lamp, high pressure mercury lamp, ultra high pressure mercury lamp, and chemical lamp , Black light lamps, microwave-excited mercury lamps and metal halide lamps.

The intensity of the light irradiation can be appropriately adjusted according to the required physical properties of the pressure-sensitive adhesive, the amount of accumulated light useful for the activity of the free radical photoinitiator is preferably 10 to 5000mJ / ㎠, more preferably 200 to 800mJ / ㎠. It is preferable to have an appropriate curing reaction time within the above range, and do not cause a decrease in cohesion, yellowing or deterioration of the support of the cured product produced by heat radiated from the lamp and exotherm during the polymerization reaction.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the present invention. Such variations and modifications are intended to be within the scope of the appended claims.

Preparation Example 1 Preparation of Amine Silane Compound

2-dimethylaminoethanol (5.0 g, 56.1 mmol) and 3-isocyanatopropylethoxysilane (21.0 g, 84.1 mmol) were added to tetrahydrofuran (100 mL) and triethylamine (0.2 mL, 1.12 mmol). After addition, the mixture was heated to reflux under nitrogen for 48 hours. After the reaction mixture was cooled to room temperature and the solvent was depressurized, column chromatography (30 wt% ethyl acetate / n-hexane) was performed to obtain the target compound (9.4 g, 50%).

The NMR measurement (Varian 300 MHz in chloroform substituted with dutium) of the aminesilane compound prepared above is as follows.

¹ H NMR (CDCl ₃ , 300 MHz)

δ 0.98 (t, J = 7.1 Hz, 2H), 1.23 (t, J = 8.0 Hz, 9H), 1.82 (Qt, J = 7.1 Hz, 14.0 Hz, 2H), 3.01 (s, 6H), 3.33 (t , J = 8.0 Hz, 2H), 3.60 (t, J = 7.1 Hz, 2H), 3.83 (q, J = 8.0 Hz, 16.0 Hz, 6H), 4.67 (t, J = 7.1, 2H), 8.03 (s , 1H)

¹³ C NMR (CDCl ₃ , 75 MHz)

δ 14.9, 19.4 (3 pcs), 25.2, 48.0, 50.7 (2 pcs), 58.4 (3 pcs), 58.9, 60.9, 157.8

Preparation Example 2 Preparation of Amine Silane Compound

The same procedure as in Preparation Example 1, except that 3-isocyanatopropylethoxysilane (17.3 g, 84.1 mmol) was used instead of 3-isocyanatopropylethoxysilane (21.0 g, 84.1 mmol). Compound (7.3 g, 44%) was obtained.

The NMR measurement (Varian 300 MHz in chloroform substituted with dutium) of the aminesilane compound prepared above is as follows.

¹ H NMR (CDCl ₃ , 300 MHz)

0.85 (s, 9H), 0.62 (t, J = 8.0 Hz, 2H), 1.81 (Qt, J = 7.1 Hz, 2H), 3.02 (s, 6H), 3.32 (t, J = 8.0 Hz, 2H), 3.58 (t, J = 7.1 Hz, 2H), 4.68 (t, J = 7.1 Hz, 2H), 8.03 (s, 1H)

¹³ C NMR (CDCl ₃ , 75 MHz)

δ 18.2 (3 pcs), 25.1, 37.4, 49.0, 53.7 (2 pcs), 58.7, 60.9, 157.8

[Example]

Example 1

(1) pressure-sensitive adhesive composition

Urethane acrylate oligomer (trade name DFCN-5, manufacturer: Negami Co., Ltd.) 45 wt%, 42.5 wt% 2-ethylhexyl acrylate and 5 wt% 1,6-nucleodiol diol diacrylate as an acrylate monomer A pressure-sensitive adhesive composition was prepared by mixing 0.5% by weight of the compound of Preparation Example 1, 2% by weight of free radical photoinitiator (Ciba, Irgacure-500) and 5% by weight of tackifier resin (FORAL85LB, Eastman).

(2) Preparation of adhesive film

The pressure-sensitive adhesive composition prepared in (1) was applied on a transparent base film coated with a silicone release agent to have a thickness of 300 μm, and the same transparent base film was laminated thereon, at a speed of 4 m / min (600 mJ / cm 2). Ultraviolet rays were irradiated and completely cured to form an adhesive.

Example 2-8 and Comparative Example 1-5

The same procedure as in Example 1, except that the composition of each component was used as shown in Table 1 below.

division Urethane acrylate oligomer Acrylate monomer Open Tense freedom additive (weight%) A-1 A-2 Aminesilanes of Formula 1 B-3 B-4 Radical photoinitiators Tackified Resin Acrylate resin syrup B-1 B-2 Example 1 45 42.5 5 - 0.5 - - 2 5 - Example 2 45 42 5 - One - - 2 5 - Example 3 45 41 5 - 2 - - 2 5 - Example 4 45 39 5 - 4 - - 2 5 - Example 5 30 50 5 - 5 - - 2 8 - Example 6 80 11 2 - 5 - - 2 - - Example 7 45 41 5 2 - - - 2 5 - Example 8 45 36 5 - 2 - - 2 - 10 Comparative Example 1 45 38 5 - - 5 - 2 5 - Comparative Example 2 30 45 5 - - - 10 2 8 - Comparative Example 3 45 41 5 - - - - 4 5 - Comparative Example 4 25 66 5 - 2 - - 2 - - Comparative Example 5 85 6 5 - 2 - - 2 - - Urethane acrylate oligomer: Brand name: DFCN-5, Negisa
A-1: 2-ethylhexyl acrylate
A-2: 1,6-nucleic acid diol diacrylate
B-1: Preparation Example 2
B-2: Preparation Example 1
B-3: triethylamine
B-4: Dimethylamino-ethylacrylate
Free radical photoinitiator: Irgacure-500, Ciba
Tackifying resin: FORAL85LB, Eastman
Acrylate resin syrup: SY-1063, Negami Chemical Co., Ltd.

Test Example

Physical properties of the pressure-sensitive adhesive composition and pressure-sensitive adhesive film prepared in Examples and Comparative Examples were measured by the following method, and the results are shown in Table 2 below.

1.Adhesion (N / 25mm)

After peeling the base film coated with the release agent laminated on the adhesive film, the base film was not laminated. The adhesive sheet was cut into a size of 25 mm × 250 mm using a super cutter, bonded to glass, fixed to an autograph, and then peeled by 180 ° PEEL at a speed of 300 m / min.

2. Adhesive failure shape

When evaluating the adhesion, the shape of the glass surface was reported, and the results were evaluated based on the following criteria.

<Evaluation Criteria>

(Double-circle): A very clean state in which no adhesive remains on the glass surface.

○: A slight amount of adhesive remains on the glass surface, but it is in a clean state.

X: A state in which many adhesives and foreign substances remain on the glass surface (agglomeration fracture).

3. Hardening shrinkage

The prepared pressure-sensitive adhesive composition was coated to have a thickness of 300 μm, and then cured by ultraviolet irradiation at a speed of 600 mJ / cm 2 using an ultraviolet irradiator. The hardened coating layer surface was visually observed, and the results were evaluated based on the following criteria.

<Evaluation Criteria>

(Double-circle): Hardening shrinkage does not occur at all. The surface is uniform and clean.

(Circle): Hardening shrinkage generate | occur | produces but there is no problem in appearance. The surface is generally uniform and clean.

X: Problems with appearance due to curing shrinkage. Uneven surface and contamination (hardening of hardening).

4. Heat resistance

After peeling off the base film coated with the release agent laminated on the adhesive film, it was laminated on the unreleased PET film. The pressure-sensitive adhesive sheet was cut into A4 size using a super cutter, bonded to glass, and then treated in an autoclave for 20 minutes at 50 ° and 5 atmospheres, and then left in an 80 ° heat oven for 100 hours.

<Evaluation Criteria>

(Double-circle): There is no defect, such as air bubble, after heat resistance evaluation.

(Triangle | delta): Less than 10 micrometers of bubbles of 1 micrometer or less generate | occur | produce on the outer side after heat-resistant evaluation.

X: Bubbles and lifting are severe after heat resistance evaluation.

5. Moisture and heat resistance

After peeling off the base film coated with the release agent laminated on the adhesive film, it was laminated on the unreleased PET film. The pressure-sensitive adhesive sheet was cut into A4 size using a super cutter, bonded to glass, and then treated in an autoclave for 20 minutes at 50 ° and 5 atm, and then left in a 60 °, 60 RH% moisture resistant oven for 100 hours.

<Evaluation Criteria>

(Double-circle): There is no defect, such as air bubble, after heat-and-moisture heat evaluation.

(Triangle | delta): Less than 10 micrometers of bubbles of 1 micrometer or less generate | occur | produce on the outside after heat-and-moisture evaluation.

X: The bubble and the generation | occurrence | production of a float are severe after heat-and-moisture evaluation.

6. Curing rate (paintability)

The extent to which the unsaturated C-C double bonds in the ethylenically unsaturated groups of the urethane acrylate oligomer component and the acrylate monomeric component were consumed as a function of time during curing was measured using Fourier transform infrared spectroscopy techniques (FT-IR).

Evaluation instrument: FT-IR

Assay: Measure the extinction level of the unsaturated CC double bond signal at about 810 cm ^-1 .

Percentage Consumption is the percentage of double bonds lost during UV irradiation, with a value of 0% before irradiation.

division adhesiveness Adhesive failure phenomenon Hardening shrinkage Heat resistance Moisture and Heat Resistance Hardening rate Example 1 15.8 ◎ ◎ ◎ ◎ 97 Example 2 21.2 ◎ ◎ ◎ ◎ 97 Example 3 27.3 ◎ ◎ ◎ ◎ 97 Example 4 28.4 ◎ ◎ ◎ ◎ 97 Example 5 30.4 ◎ ○ ◎ ◎ 97 Example 6 23.3 ◎ ◎ ◎ ◎ 75 Example 7 26.8 ◎ ◎ ◎ ◎ 97 Example 8 25.1 ◎ ◎ ◎ ◎ 97 Comparative Example 1 10.3 ◎ ○ × × 97 Comparative Example 2 13.7 ◎ × × × 97 Comparative Example 3 8.6 ◎ ○ × × 85 Comparative Example 4 11.3 ◎ × × × 97 Comparative Example 5 9.4 × ○ × × 57

As shown in the above table, Examples 1 to 8 containing urethane acrylate oligomer, acrylate monomer, a specific amine silane compound having a lower alkyl group and a specific amine silane compound having a tertiary amine group and a free radical photoinitiator according to the present invention The pressure-sensitive adhesive composition not only maintains the physical properties of the pressure-sensitive adhesive composition itself, such as coating properties and adhesion, but also hardly shrinkage occurs during photopolymerization, so that the thickness is uniform, durability of surface appearance, heat and moisture resistance, and the curing rate are improved. .

On the contrary, Comparative Example 1 was inferior in durability due to triethylamine remaining as an impurity after the reaction was completed, and Comparative Example 2 using dimethylamino-ethyl acrylate caused curing shrinkage. In addition, Comparative Example 3, which does not use a tertiary amine, uses an excess photoinitiator to increase the degree of curing, but the durability is inferior, and Comparative Examples 4 to 5 in which the content of the urethane acrylate oligomer deviates from 30% by weight to 80% by weight are also durable. And it was confirmed that the degree of hardening.

Claims (8)

Optical pressure-sensitive adhesive composition comprising 30 to 80% by weight of urethane acrylate oligomer, 10 to 60% by weight of acrylate monomer, 0.1 to 5% by weight of amine silane compound represented by Formula 1 and 0.1 to 5% by weight of free radical photoinitiator:
[Formula 1]

Wherein, R ₁ , R _2, R ₃ , R ₄ and R ₅ are each an alkyl group having 1 to 4 carbon atoms.
The optical pressure-sensitive adhesive composition of claim 1, wherein the acrylate monomer is 1 to 4 functional.
The method according to claim 1, wherein R ₁ , R _2, R ₃ , of the aminesilane compound, R ₄ and R ₅ is an optical pressure-sensitive adhesive composition, each of which is an alkyl group having 1 to 2 carbon atoms.
The optical pressure-sensitive adhesive composition of claim 3, wherein R ₄ and R ₅ of the aminesilane compound are methyl groups, respectively.
The optical pressure-sensitive adhesive composition of claim 1, wherein the composition further comprises an additive of an acrylate resin syrup, a tackifier resin, or a mixture thereof.
The adhesive which hardened the adhesive composition of any one of Claims 1-5.
Transparent substrate film;
Adhesive film comprising the pressure-sensitive adhesive of claim 6 formed on one surface of the transparent base film.
The pressure-sensitive adhesive film of claim 7, wherein the pressure-sensitive adhesive has a thickness of 25 to 1000㎛.