TWI454548B - Dual curable adhesive composition - Google Patents

Description

Double-cure adhesive composition

The present invention relates to a dual-cure adhesive composition, and more particularly to a dual-cure adhesive composition for use in displays and touch panels.

With the rapid development of the information industry, electronic products such as mobile phones, personal digital assistants, and notebook computers have become a necessity in people's daily lives. Among these electronic products, the display is an indispensable human-machine communication interface. How to provide a lighter, thinner and better visual product has always been one of the main research and development purposes of the industry. In recent years, the touch panel has been integrated with the display and used in various electronic products, allowing users to directly select various operations on the panel to provide a more convenient and user-friendly operation mode.

As shown in FIG. 1 , a cover glass 11 composed of glass is generally provided on the outside of the touch panel, and the main purpose thereof is to strengthen the touch panel and provide a protection function; the adhesive layer 12 is used to cover the glass cover ( Cover glass) is attached to the ITO film or ITO glass 13 on the touch panel.

Adhesives are used in a wide range of applications. Among them, optically transparent adhesives have been widely used in displays and touch panels to provide adhesion. For example, attaching the touch panel to the display and bonding the ITO film or ITO glass in the touch panel to the outer glass is a typical application range of such an adhesive. In order not to affect the visual effect, such an adhesive must have an optical property such as an appropriate transmittance and refractive index.

When light is transmitted in different media, the difference in refractive index causes light Reflection, affecting the light output rate. Optical components such as films or glasses typically have a relatively high refractive index, for example, the refractive index of the glass is about 1.52. However, commonly used optically clear adhesives, such as acrylate adhesives, can provide refractive indices generally ranging from about 1.4 to about 1.45, which still do not meet the needs of the industry. Therefore, in order to reduce the reflection phenomenon of light on the optical element and improve the transmittance, there is a need in the art for an optically transparent adhesive having a high refractive index.

The optically transparent adhesives currently used in the industry are in the form of optically clear adhesives and liquid optically clear adhesives. The optical tape must be kept flat at all times during the bonding process, otherwise it will easily cause bubbles or wrinkles. In addition, the optical tape has the disadvantages of cumbersome bonding steps, inability to rework, and necessity to have a certain thickness. In order to improve the process yield, simplify the process steps and meet the needs of thinner and lighter products, liquid optical adhesives have received increasing attention in the new generation process.

Liquid optical adhesives generally have problems such as poor light transmittance and low refractive index, and their fluidity must be properly adjusted to avoid overflow problems. In some cases, for example, when applied to a touch panel, it is necessary to have appropriate softness to provide better cushioning properties, and to avoid undesirable visual effects such as water ripple caused by stress on the touch panel.

In addition, as shown in FIG. 1 , the cover glass 11 of the touch panel is usually coated with a layer of border paint layer 14 , which is mostly black paint, and functions to cover the underlying ITO film. Or the line area of the ITO glass 13 to achieve aesthetics and prevent the line from being exposed to external light (such as ultraviolet light); however, the general liquid optical adhesive composition is a light curing system. When the adhesive composition is not illuminable by light, for example, the adhesive composition 121 located in the area below the bezel paint layer 14, as shown in FIG. 1, it is unable to receive sufficient UV light because it is covered by the bezel paint layer 14. The adhesive composition 121 is liable to cause incomplete curing, and the adhesiveness is lowered.

In view of the above, the present invention provides a double-cured adhesive composition having a high refractive index, that is, a photocurable and heat-curable adhesive composition. As shown in FIG. 1, the adhesive composition provided by the present invention can be covered by the border paint layer through the UV light irradiation and heating step so as to fail to receive sufficient UV light to irradiate the photocured portion (121) via the heating step. Heat curing. The adhesive composition of the present invention has suitable fluidity and softness, and can fill the difference between the frame paint layer 14 and the adhesive composition 121 and the ITO glass 13, which is easy to apply and fit. It can also improve production yield and effectively solve the problems in the prior art.

In order to solve the above problems, the main object of the present invention is to provide a dual-cure adhesive composition which can be used as a liquid optically clear adhesives (LOCA) in displays and touch panels.

The present invention provides a dual-cure adhesive composition comprising: a) a (meth) acrylate oligomer having at least one unsaturated group; b) a monofunctional monomer, a polyfunctional monomer or a mixture; c) a (meth)acrylic resin having an isocyanate group; d) a polyester polyol resin; e) an initiator; f) A plasticizer having a refractive index of 1.49 or more.

The detailed description of the present invention and the preferred embodiments thereof will be described in the following description.

In the adhesive composition of the present invention, component (a) is a (meth) acrylate oligomer having at least one unsaturated group, preferably having two or more unsaturated groups. The unsaturated group may be, but not limited to, a vinyl group.

The type of the above acrylate oligomer is, for example but not limited to, urethane (meth) acrylate, such as an aliphatic polyurethane (meth) acrylate ( Aliphatic urethane (meth)acrylate), aromatic urethane (meth) acrylate, aliphatic urethane di (meth) acrylate (aliphatic urethane di) (meth)acrylate), aromatic urethane di(meth)acrylate, siliconized urethane (silicon urethane) Meth)acrylate), aliphatic urethane di(meth)acrylate, aromatic urethane di (aromatic urethane di) Meth)acrylate); epoxy (meth)acrylate, such as bisphenol-A epoxy di(meth)acrylate, phenolic epoxy ( Novolac epoxy (meth)acrylate; polyester (meth)acrylate, such as polyester II ( Yl) acrylate (polyester di(meth)acrylate); (meth)acrylate; (meth)acrylate; or a mixture thereof. According to the invention, a polyurethane (meth) acrylate is preferred.

Commercially available acrylate oligomers useful in the present invention include: manufactured by Eternal Corporation under the trade names 6101-100, 611A-85, 6112-100, 6113, 6114, 6123, 6131, 6144-100, 6145-100. , 6150-100, 6160B-70, 621A-80, 621-100, EX-06, 6315, 6320, 6323-100, 6225-100, 6327-100, 6336-100 or 6361-100; produced by Sartomer, The trade names are CN9001, CN9002, CN9004, CN9006, CN9014, CN9021, CN963J75, CN966J75, CN973J75, CN962, CN964, CN965, CN940, CN945 or CN990.

According to the present invention, the acrylate oligomer is used in an amount of from about 40% to about 80%, preferably from 45% to about 75%, based on the total weight of the composition.

In the adhesive composition of the present invention, the component (b) is a monofunctional monomer, a polyfunctional monomer or a mixture thereof, and the component (b) can further provide a bridging action to reduce the phenomenon of precipitation of the plasticizer. The above functional group means an unsaturated group, for example, an ethylenically unsaturated group, and the kind of the above monomer is, for example but not limited to, a (meth)acrylic monomer, a (meth)acrylic monomer or a mixture thereof It is preferably a (meth) acrylate monomer.

Monofunctional monomers suitable for use in the present invention may be selected from, but not limited to, methyl methacrylate (MMA), butyl methacrylate, 2-phenoxyethyl acrylate (2-phenoxy). Ethyl acrylate), ethoxylated 2-phenoxy ethyl acrylate Acrylate), 2-(2-ethoxyethoxy)ethyl acrylate, cyclic trimethylolpropane formal acrylate, β -β-carboxyethyl acrylate, lauryl methacrylate, isooctyl acrylate, stearyl methacrylate, isodecyl acrylate Isodecyl acrylate, isoborny methacrylate, benzyl acrylate, 2-hydroxyethyl metharcrylate phosphate, hydroxyethyl acrylate A group consisting of (hydroxyethyl acrylate, HEA), 2-hydroxyethyl methacrylate (HEMA), and mixtures thereof.

The polyfunctional (meth) acrylate monomer suitable for use in the present invention may be selected from, but not limited to, 3-hydroxy-2,2-dimethylpropionic acid 3-hydroxy-2,2-dimethyl Hydroxyvalyl hydroxypivalate diacrylate, ethoxylated 1,6-hexanediol diacrylate, dipropylene glycol diacrylate, tricyclodecane Tricyclodecane dimethanol diacrylate, ethoxylated dipropylene glycol diacrylate, neopentyl glycol diacrylate, propoxylated neopentyl glycol Diacrylate), ethoxylated bisphenol-A dimethacrylate, 2-methyl-1,3-propanediol diacrylate (2-methyl-) 1,3-propanediol diacrylate), ethoxylated 2-methyl-1,3-propanediol diacrylate, 2-butyl-2-ethyl-1, 2-butyl-2-ethyl-1,3-propanediol diacrylate, ethylene glycol dimethacrylate (EGDMA), diethylene glycol dimethacrylate (diethylene) Glycol dimethacrylate), Tris(2-hydroxyethyl)isocyanurate triacrylate, pentaerythritol triacrylate, ethoxylated trimethylolpropane triacrylate (ethoxylated trimethylolpropane triacrylate), propoxylated trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol tetraacrylate, pentylenetetraol Ethoxylated pentaerythritol tetraacrylate, ditrimethylolpropane tetraacrylate, propoxy Propoxylated pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, tripropylene glycol dimethacrylate, 1,4-butanediol dimethacrylate (1,4- Butanediol dimethacrylate), 1,6-hexanediol dimethacrylate, allylated cyclohexyl dimethacrylate, isocyanuric acid dimethacrylate Isocyanurate dimethacrylate, ethoxylated trimethylolpropane Trimethacrylate), propoxylated glycerol trimethacrylate, tris(acryloxyethyl)isocyanurate, trimethylolpropane triacrylate And a group of mixtures thereof.

Preferably, the monofunctional or polyfunctional monomer usable in the present invention is 2-phenoxy ethyl acrylate, lauryl methacrylate, isodecyl. Isodecyl acrylate, isoborny methacrylate, trimethylolpropane trimethacrylate, pentaerythritol tetraacrylate, ethoxylated trishydroxylate Ethoxylated trimethylol propane trimethacrylate, propoxylated glycerol trimethacrylate, trimethylolpropane triacrylate.

Commercially available monofunctional or polyfunctional monomers useful in the present invention include: manufactured by Eternal Corporation under the trade names EM210, EM214, EM223, EM328, EM2308, EM231, EM219, EM90, EM70, EM235, EM2381, EM2382. EM2383, EM2384, EM2385, EM2386, EM2387, EM331, EM3380, EM241, EM2411, EM242, EM2421 or EM265; manufactured by Sartomerl, under the trade names SR242, SR949, SR444, CD501, SR454, SR454HP, SR492, SR9008, SR9035 or CD9051 and so on.

According to the present invention, the kind and amount of the component (b) are generally adjusted depending on the kind of the component (a), the added amount, and the use of the resulting adhesive composition; for example, a monofunctional acrylate monomer may be added as a group. Sub-(b), the monofunctional acrylate monomer has the function of a diluent, can appropriately adjust the viscosity of the obtained adhesive composition, and improve the operability of coating application; and can also use a polyfunctional acrylate monomer as a component. (b) In this case, a large number of functional groups can be reacted, which is advantageous for the subsequent curing reaction. The person skilled in the art of the present invention has the general knowledge. According to the disclosure content of the present specification and related knowledge, the types and addition amounts of component (a) and component (b) can be adjusted as needed to obtain an adhesive combination having desired properties. Things. In general, component (b) is used in an amount of from about 1% to about 40%, preferably from about 3 to 30%, based on the total weight of the composition.

Component (c) suitable for use in the present invention is a (meth) acrylate resin having an isocyanate group, preferably a (meth) acrylate oligomer having one or more isocyanate groups, one or more of the above The isocyanate-based (meth) acrylate oligomer refers to a structure in which the main chain of the oligomer has an acrylate homopolymer or a copolymer, and the side chain has one or more isocyanate-groups . . The above oligomers comprise polymerized units derived from one or more of the following monomers: an unsaturated aliphatic compound having one or more isocyanate groups, such as 2-isocyanatoethyl (meth). Acrylate.), 3-yl isocyanate, 4-isocyanatobut-1-ene; epoxy (meth) acrylate, such as glycidyl (meth)acrylate Glycidyl (meth)acrylate; phenolic epoxy (meth) acrylate, such as bisphenol-A epoxy di (meth) acrylate; alkyl (methyl) Acrylates such as n -butyl methacrylate; alkoxy (meth) acrylates such as 2-(2-ethoxyethoxy)ethyl acrylate (2-(2-ethoxyethoxy) )ethyl acrylate).

Commercially available isocyanate-containing (meth)acrylic resins useful in the present invention include: manufactured by Bayer under the trade names Desmolux® U100, Desmolux® D100, Desmolux® VP LS 2265, Desmolux® VP LS 2396, Desmolux® VP LS 2308, Desmolux® U375H, Desmolux® VP LS 2110, Desmolux® VP LS 2220, Desmolux® VP LS 2266, Desmolux® VP LS 2381, Desmolux® XP 2490, Desmolux® XP 2491, Desmolux® XP 2510, Desmolux® XP 2513 Desmolux® XP 2587, Desmolux® U200, Desmolux® VP LS 2299, Desmolux® VP LS 2337, Desmolux® XP 2609 and Desmolux® XP 2614.

The isocyanate group-containing (meth)acrylic resin of the present invention is used in an amount of from about 0.1% to about 10%, preferably from about 1% to 5%, based on the total mass of the composition.

The polyester polyols suitable as component (d) in the present invention are generally linear and have a range of from about 500 to about 5,000, preferably from about 600 to about 4,000, more preferably from about A number average molecular weight (Mn) of from 700 to about 2,500. The number average molecular weight can be determined by analyzing the number of terminal functional groups of a specific weight of the polymer, for example, by Gel Permeation Chromatography (GPC). Appropriate hydroxyl group The terminal polyester polyols typically have an "acid value" of about 1.3 or less, and typically about 0.8 or less. "Acid value" means the number of milligrams of potassium hydroxide required to neutralize 1 gram of the hydroxyl terminated polyester, for example, as determined by conventional titration.

The polyester polyol of the present invention can be prepared by any suitable method, for example, by using a dicarboxylic acid or an anhydride thereof (or a combination of an acid and an acid anhydride) with a polyol, or by taking a caprolactone (for example, ε The ring opening reaction of the ester) is obtained. According to one embodiment of the invention, the polyester polyol is derived from a dicarboxylic acid or anhydride and a glycol.

The dicarboxylic acid or anhydride used to prepare the above polyester polyol has from about 4 to about 15 carbon atoms. Suitable carboxylic acids and anhydrides are selected from the group consisting of succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, isophthalic acid, and p-phenylene Formic acid, cyclohexanedicarboxylic acid, phthalic acid, and tetrahydrophthalic acid, and anhydrides thereof, and mixtures thereof. Preferred acids include adipic acid, suberic acid, azelaic acid and sebacic acid.

The polyol used to prepare the polyester polyol is an aromatic alcohol or an aliphatic alcohol containing at least two hydroxyl groups, or a combination thereof. The aliphatic alcohol is exemplified by a linear, branched or cyclic diol comprising 2 to 15 (preferably 4 to 8) carbon atoms; and, for example, an aromatic alcohol, such as bisphenol -A, a diol such as a hydroxylated bisphenol. Preferred polyols are selected from aliphatic diols including, for example, ethylene glycol, 1,2-propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, and , 5-pentanediol, 1,6-hexanediol, 2,2-dimethyl-1,3-propanediol, 1,4-cyclohexanedimethanol, 1,4-cyclohexanediethanol, ten Methylene glycol, dodecamethylene glycol, 2-methyl-1,3-propanediol, 3-methyl-1,5- Pentandiol, 2,2,4-trimethyl-1,3-pentanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, diethylene glycol, polyethylene glycol, dipropylene glycol, polypropylene glycol, a group consisting of dibutylene glycol, polytetramethylene glycol, dimer diol, and mixtures thereof; preferably selected from the group consisting of 1,3-butanediol, 1,4-butanediol, 1,5-pentane Glycol, 1,6-hexanediol, 2,2-dimethyl-1,3-propanediol, 1,4-cyclohexanedimethanol, 1,4-cyclohexanediethanol, decamethylidene Alcohol, dodecamethylene glycol, 2-methyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2,2,4-trimethyl-1,3-pentane Alcohol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol polypropylene glycol, polyethylene glycol polyhexylene glycol, diethylene glycol, dipropylene glycol, dibutylene glycol, polybutylene glycol, dimerization a group consisting of a diol, and a mixture thereof; preferably selected from the group consisting of 2,2-dimethyl-1,3-propanediol, 1,4-cyclohexanedimethanol, and 1,4-cyclohexanediethanol , decamethyl glycol, dodecamethylene glycol, 2-methyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2,2,4-trimethyl- 1,3-pentanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol polypropylene glycol, The group consisting of polyethylene glycol, hexylene glycol, diethylene glycol, dipropylene glycol, bis butylene glycol, polyethylene glycol and mixtures thereof.

Commercially available polyester polyol resins useful in the present invention include those manufactured by Eternal under the trade names ETEROL 5100®, ETEROL 5120®, ETEROL 5200®, ETEROL 5330®, ETEROL 5400®, ETEROL 5401® Series, ETEROL 5420® series, ETEROL 5550® series, ETEROL 5600® series, ETEROL 5641® series. Or manufactured by Bayer under the trade names Baycoll® AD1110-CN, Baycoll® AD1115-CN, Baycoll® AD1122-CN, Baycoll® AD1225-CN, Baycoll® AD2047- CN, Baycoll® AD2055-CN, Baycoll® AD5027, Baycoll® AS1155-CN, Baycoll® AS2060-CN, Baycoll® AV2113-CN, Baycoll® CD2084-CN, Baycoll® DS1165-CN, Baycoll® DV1245-CN series.

The polyester polyol resin of the present invention is used in an amount of from about 0.1% to about 10%, preferably from about 1% to 5%, based on the total mass of the composition.

The isocyanate group-containing (meth)acrylic resin and the polyester polyol resin used in the adhesive composition of the present invention can provide heat curing (crosslinking) properties of the composition, so that light can be achieved in the adhesive composition of the present invention. The combination of curing and heat curing (crosslinking) overcomes the defects that may be caused by only the photocuring system in the prior art, such as incomplete dark curing, incomplete deep curing, and incomplete curing of non-planar structures.

Further, the isocyanate group-containing (meth) acrylate and the polyester polyol resin used in the adhesive composition of the present invention have good compatibility with other components and can adjust the bonding stress of the entire composition. Provide appropriate rigidity to facilitate heavy work. In particular, the adhesive composition of the present invention has no solvent component, and therefore, there must be good compatibility between the components, and it is used in the amount defined by the present invention, and the composition is less prone to qualitative change, precipitation or storage stability. Poor and other issues, and has the advantages of moderate fluidity and softness for subsequent processing and application.

The initiator (component (e)) used in the adhesive composition of the present invention is not particularly limited, and is free radically generated by providing heat energy or light irradiation, and is caused by the transfer of free radicals. Polymerizer. The amount of initiator used, depending on the polymerizable monomer/oligomer contained in the adhesive composition The type and amount of the substance are adjusted. Generally, the amount of initiator is from about 0.1% to about 10%, preferably from about 0.1% to about 6%, based on the total weight of the composition.

The initiator of the present invention comprises a thermal initiator and a photoinitiator. Photoinitiators suitable for use in the present invention, such as, but not limited to, benzophenone, benzoin, 2-hydroxy-2-methyl-1-phenylpropan-1-one (2-hydroxy-2-methyl-1-phenyl-propan-1-one), 2,2-dimethoxy-1,2-diphenylethan-1-one (2,2-dimethoxy-1, 2-diphenylethan-1-one), 1-hydroxy cyclohexyl phenyl ketone, 2,4,6-trimethylbenzhydryldiphenylphosphine oxide (2,4, 6-trimethylbenzoyl diphenyl phosphine oxide), or a mixture thereof. Preferred photoinitiators are benzophenone, 1-hydroxycyclohexyl phenyl ketone or 2,4,6-trimethylbenzimidyl diphenylphosphine oxide. Generally, the photoinitiator is present in an amount of from about 0.1% to about 5%, preferably from about 0.1% to about 3%, based on the total weight of the composition.

The hot starter used in the present invention is, for example but not limited to, Benzoyl peroxide, Cumyl hydroperoxide, Dicumyl peroxide, and Ternary butyl. Hydrogen peroxide (tert-Butyl hydroperoxide), tert-Butyl monoperoxymaleate, acetyl peroxide, dilauroyl peroxide, the above peroxide a mixture of one or more of amino acid or sulfonic acid, a mixture of one or more of the above peroxides with a cobalt-containing compound, azobisisobutyronitrile (AIBN), or a mixture of such. Preferably, the hot initiator is selected from the group consisting of tert-butyl hydroperoxide, peroxybutylbutyl maleate, and diethyl hydrazine. a group of substances, lauryl peroxide, and mixtures thereof. Generally, the hot starter is present in an amount of from about 0.1% to about 5%, preferably from about 0.1% to about 3%, based on the total weight of the composition. According to a preferred embodiment of the present invention, the amount of the hot starter of the present invention is from 5:1 to 1: relative to the total weight ratio of the isocyanate group-containing (meth) acrylate to the polyester polyol resin. Between 20, preferably between 2:1 and 1:10. If the amount of hot initiator is greater than 5:1 by weight relative to the total weight ratio of isocyanate-containing (meth) acrylate to polyester polyol resin, excessive thermal initiator results in poor stability of the composition, resulting in storage Or it is easy to produce quality change during transportation; if the total amount of hot initiator is less than 1:20 relative to the total weight ratio of isocyanate group-containing (meth) acrylate to polyester polyol resin, too little heat starts The agent results in a composition that is susceptible to heat curing and is incompletely cured due to too little initiator.

The plasticizer used in the present invention must have a refractive index of 1.49 or more. A plasticizer is an inert organic material that is physically combined with a polymer to produce a homogeneous phase that increases the softness and flexibility of the polymer. The type of plasticizer is well known to those of ordinary skill in the art to which the invention pertains, for example: phthalates, aliphatic dibasic esters, phosphates, benzene polyesters, alkyl sulfonates , a polyol ester or an epoxy compound or a mixture thereof. The plasticizer used in the present invention is preferably selected from the group consisting of phthalates, phosphates or mixtures thereof.

According to an embodiment of the present invention, the plasticizer used in the present invention is a phthalate having the following formula: Wherein R ₁ and R ₂ may be the same or different and are each independently a linear or branched C ₁ -C ₁₈ alkyl group, a C ₃ -C ₈ cycloalkyl group, a C ₂ -C ₈ alkenyl group or a C ₆ -C _{14 group.} Aralkyl group, preferably methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, decyl, decyl, undecyl, propenyl, cyclopropyl, cyclobutane Base, cyclopentyl, cyclohexyl, benzyl.

The phthalate ester suitable for use in the present invention is preferably dimethyl phthalate (C ₆ H ₄ (COOCH ₃ ) ₂ ) or diethyl phthalate (C ₆ H ₄ (COOC ₂ H ₅ )). ₂ ), dipropylene phthalate (C ₆ H ₄ (COOCH ₂ CH=CH ₂ ) ₂ ), dipropyl phthalate (C ₆ H ₄ (COOCH ₂ CH ₂ CH ₃ ) ₂ ), adjacent Dibutyl phthalate (C ₆ H ₄ [COO(CH ₂ ) ₃ CH ₃ ] ₂ ), diisobutyl phthalate (C ₆ H ₄ [COOCH ₂ CH(CH ₃ ) ₂ ] ₂ ), Dipentyl phthalate (C ₆ H ₄ [COO(CH ₂ ) ₄ CH ₃ ] ₂ ), dicyclohexyl phthalate (C ₆ H ₄ (COOC ₆ H ₁₁ ) ₂ ), phthalic acid Benzyl benzoate (CH ₃ (CH ₂ ) ₃ OOCC ₆ H ₄ COOCH ₂ C ₆ H ₅ ), dihexyl phthalate (C ₆ H ₄ [COO(CH ₂ ) ₅ CH ₃ ] ₂ ) Diisoheptyl phthalate (C ₆ H ₄ [COO(CH ₂ ) ₄ CH(CH ₃ ) ₂ ] ₂ ), bis(2-ethyl)hexyl phthalate (C ₆ H ₄ [ COOCH ₂ CH(C ₂ H ₅ )(CH ₂ ) ₃ CH ₃ ] ₂ ), di-n-octyl phthalate (C ₆ H ₄ [COO(CH ₂ ) ₇ CH ₃ ] ₂ ), phthalic acid Diisooctyl ester (C ₆ H ₄ [COO(CH ₂ ) ₅ CH(CH ₃ ) ₂ ] ₂ ), diisononyl phthalate (C ₆ H ₄ [COO(CH ₂ ) ₆ CH(CH _{3 )} ) _{2 2} ), diisononyl phthalate (C ₆ H ₄ [COO(CH ₂ ) ₇ CH(CH ₃ ) ₂ ] ₂ ), diundecyl phthalate (C ₆ H ₄ [ COO(CH ₂ ) ₁₀ CH ₃ ] ₂ ) or a mixture thereof; more preferably dimethyl phthalate (C ₆ H ₄ (COOCH ₃ ) ₂ ), diethyl phthalate (C ₆ H ₄ ( COOC ₂ H ₅ ) ₂ ), dipropylene phthalate (C ₆ H ₄ (COOCH ₂ CH=CH ₂ ) ₂ ), butyl phthalate benzyl ester (CH ₃ (CH ₂ ) ₃ OOCC ₆ H ₄ COOCH ₂ C ₆ H ₅ ), diisononyl phthalate (C ₆ H ₄ [COO(CH ₂ ) ₆ CH(CH ₃ ) ₂ ] ₂ ) or a mixture thereof.

According to another embodiment of the present invention, the plasticizer used in the present invention is a phosphate having the following formula (2) or formula (3):

Wherein R ₃ , R ₄ and R ₅ may be the same or different and each independently is a linear or branched C ₁ -C ₁₂ alkyl group, a phenyl group or a naphthyl group, and the phenyl or naphthyl group may be subjected to 1 to 3 Linear or branched C ₁ -C ₄ alkyl substituted; R ₆ is a linear or branched C ₁ -C ₁₂ alkyl or phenyl group, which may be 1 to 3 straight or branched Chain C ₁ -C ₄ alkyl substitution.

According to a preferred embodiment of the present invention, the plasticizer used in the present invention has a phosphate of the following formula (4): Wherein n may be the same or different and each independently is 0, 1, 2 or 3, and R may be the same or different and each independently is a linear or branched C ₁ -C ₄ alkyl group, preferably a methyl group.

According to another preferred embodiment of the present invention, the plasticizer used in the present invention has a phosphate of the following formula (5): Wherein n may be the same or different and each independently is 0, 1, 2 or 3, and R may be the same or different and each independently is a linear or branched C ₁ -C ₄ alkyl group, preferably a methyl group.

The use of phosphate ester plasticizers can have a flame retardant effect, reducing the possibility of burning materials and reducing fires without the need for additional flame retardants.

The phosphate ester suitable for use in the present invention is preferably triphenyl phosphate (TPP), tricresyl phosphate (TCP), tri(isopropylphenyl)phosphate, phosphoric acid. Cresyl diphenyl phosphate, tetraphenyl resorcinol diphosphate, resorcinol bis[bis(2,6-dimethylphenyl)phosphate] (Tetrakis ( 2,6-dimethylphenyl)1,3-phenylene bisphosphate) or a mixture thereof.

According to the invention, the amount of the plasticizer is about the total weight of the composition. From 5% to about 60%, preferably from about 10% to about 50%. According to a preferred embodiment of the present invention, when the amount is more than 60%, the composition is liable to cause a qualitative change due to poor storage stability; when the amount is less than 5%, it is easy to cause a paste because the refractive index value of the composition is not provided. The visual beauty of the components is not good.

The adhesive composition of the present invention may optionally comprise any additives known to those skilled in the art such as, but not limited to, synergists, sensitizers, coupling agents, dispersing agents, moisturizing agents. A wetting agent, a thickening agent, an antifoaming agent, a chain transfer agent, an anti-yellowing agent or a rocking agent.

The adhesive composition of the present invention can be applied to one component and bonded to another component using any method well known to those skilled in the art to which it is conventionally known, followed by irradiation with an energy ray. For example, an ITO film or ITO glass used as a sensor in a touch panel can be bonded to a glass cover or a cover lens using the adhesive composition of the present invention, or an ITO used as a sensor can be used. The film or ITO glass is bonded to another ITO film or ITO glass, or the touch panel is attached to the LCD panel module, and the application method is, for example but not limited to:

(a) (meth)acrylate oligomers, mono- and polyfunctional monomers, isocyanate-containing (meth)acrylic resins and polyester polyol resins, starters and plasticizers, and appropriate The additive is mixed to form a composition; (b) the composition obtained in the step (a) is applied to the LCD panel module at a thickness of about 100-300 m, and then to the substrate to be bonded, such as Glass cover, protective cover, touch panel, ITO film or ITO glass.

(c) Irradiating the energy ray to cure it.

(d) Heating causes the portion that is not irradiated with the energy ray to be thermally cured.

As in the above step (c), the adhesive composition of the present invention can be cured by photopolymerization by irradiation of an energy ray, and fails to receive a portion of the irradiation energy, such as an adhesive composition which is covered by the border paint. It is thermally cured through step (d) and provides good adhesion after curing. The above energy ray refers to a light source of a certain range of wavelengths, such as ultraviolet light, infrared light, visible light or high energy ray (electron beam), etc., preferably ultraviolet light. The irradiation intensity may be from 100 to 5000 mJ/cm ² (mJ/cm ² ), preferably from 200 to 2000 mJ/cm ² . According to a preferred embodiment of the present invention, the heating temperature used in the step (d) is not more than 80 ° C to be suitable for the operating temperature allowed by the bonded substrate. Taking the LCD panel module as an example, the polarizing plate material known in the module is prone to change or deform (such as warping) in a environment of more than 80 ° C, so that even if the component is successfully bonded at the temperature, Used as a follow-up. Therefore, the use of the composition of the present invention not only provides good adhesion and is easy to handle, but also avoids the above drawbacks.

The adhesive composition of the present invention adds a plasticizer having a refractive index of more than 1.49. Since the crosslink density of the composition is high after curing, the plasticizer is not easily precipitated, does not cause environmental problems, and has good light transmittance and high after curing. Refractive index. The adhesive composition of the present invention has a higher overall refractive index after curing than the adhesive composition without the plasticizer. The adhesive composition of the invention has good softness and can be used in optical electronic products, especially in displays and touch panels, as an adhesive or liquid optical glue (LOCA), which can provide a buffering effect and enhance the visual beauty of the screen. Furthermore, the adhesive composition of the present invention has It has suitable fluidity, is good for coating and lamination, and has good reworkability. Therefore, it can be applied to replace optical tapes in related fields such as displays and touch panels, simplifying the process and improving the yield.

The following examples are intended to illustrate the invention and are not intended to limit the scope of the invention. Modifications and variations that may be readily made by those skilled in the art are included within the scope of the disclosure of the present disclosure and the scope of the appended claims.

Example In the examples, the abbreviations used are defined as follows:

DPC: Differential Photoscanning Calorimetry

DSC: Differential Scanning Calorimeter

Examples 1 to 7 and Comparative Examples 1 to 3

The glues of the photocurable adhesive compositions of Examples 1 to 7 and Comparative Example 1 were prepared in the manner described below, and the compositions are as listed in Table 1.

First, the components were mixed in the weights (in grams) listed in Table 1, and stirred at room temperature and in a dark room until completely mixed uniformly to form a photocurable adhesive composition.

(a): Polyurethane acrylate oligomer (produced by Changxing Company, EX-06)

(b): Monofunctional monomer (isodecyl acrylate; produced by Changxing Co., Ltd., EM210)

(c): (meth)acrylic resin containing isocyanate group (manufactured by Bayer, D100)

(d): Polyester polyol resin (produced by Changxing Company, Eternal 5200)

(e1): Photoinitiator (1-hydroxycyclohexyl phenyl ketone; produced by BASF, Irgacure 184)

(e2): hot starter (349745000 corresponding product (LPO) produced by Dilauroyl peroxide/ACROS)

(f): Plasticizer: Tricresyl phosphate (TCP)

^* (f): Plasticizer: AD-191 CAS No.181028-79-5

^** (f): plasticizer: diisononyl phthalate C ₆ H ₄ [COO(CH ₂ ) ₆ CH(CH ₃ ) ₂ ] ₂ (a)-(f), ^* (f) Both ^{** and} (f) have a purity of >99%.

Comparative example 4

Commercially available optical glue: DBA2000, DuPont.

Test Method 1:

Viscosity : The viscosity of the glue was tested at 25 ° C using a Brookfield LV viscometer.

Refractive index : The refractive index of the glue was measured using a DR-A1 A-Line inflection meter (ATAGO). Subsequently, the glue was cured by ultraviolet light at an irradiation intensity of 3000 mJ/cm ² , and the refractive index after curing was measured.

Hardness : The hardness of the cured optical gel was measured using a PGR305 TYPE E hardness meter (TECLOCK).

Penetration : The optical gel penetration after curing was measured using an NDH 5000W haze meter (Nippon Denshoku Co., Ltd.).

Test Results:

The test results obtained above are recorded in Table 2.

It can be seen from Table 1 and Table 2 that the adhesive composition of the present invention has a transmittance of more than 99% after curing; and compared to the adhesive composition containing no plasticizer (Comparative Example 2) and a commercially available optical adhesive (Comparative Example) 4. The adhesive composition of the present invention has a high refractive index and can effectively increase the refractive index after curing to 1.48. It can be seen from Examples 1-4 that the refractive index after curing increases with the content of the plasticizer in the component. The rate value also increases; and it can be seen from Examples 1, 6, and 7 that the type of the plasticizer in the composition is not particularly limited and may be selected from various phthalates or phosphates.

In addition, the adhesive composition of the present invention can reduce the hardness of the prepared coating by containing a plasticizer, provide better cushioning properties, and avoid undesirable visual effects such as water ripple caused by the stress of the touch panel.

Test Method 2:

<Mask experiment>

DPC conversion rate: When the thickness of the glue is 100-200 mm, the conversion rate of the reaction is determined by the amount of exposure energy. By plotting, the Y-axis can be obtained as a curve of the conversion rate X-axis as the exposure energy, from which it can be determined whether the glue of 100-200 mm is completely cured.

Operation method: Take a DSC-measured aluminum pan, which is packed in liquid glue to cut about 1-2mg, put it into a DSC instrument with UV exposure equipment, and measure the heat change pattern. The conversion-exposure energy pattern can be obtained by calculation, as shown in Figure 3-5.

After the adhesive composition of the present invention (Example 3) was exposed to an exposure energy of 250 mJ/cm ² , the graph of DPC conversion with each exposure time was as shown in Fig. 3 . The exposure times of A, B, C, and D were 0.5, 1.0, 1.5, and 2.0 hours, respectively. As is apparent from the results of Fig. 3, the adhesive composition of the present invention can be completely cured under the conditions of D (exposure at 250 mJ/cm ² , 60 ° C for 2 hours).

The graph of DPC conversion of the adhesive composition of the present invention (Example 3) at a heating temperature of 70 ° C is shown in Fig. 4 . The exposure times of A, B, C, and D were 0.5, 1.0, 1.5, and 2.0 hours, respectively. From the results of Fig. 4, it can be seen that the adhesive composition of the present invention has a DPC conversion rate of 70% under the conditions of D (heating at 70 ° C for 2 hours). Therefore, it can be inferred that the adhesive composition of the present invention has a DPC conversion of more than 50% under heating conditions (greater than 50 ° C). The above results were compared with Comparative Example 1 (without adding a thermoplastic resin) and Comparative Example 3 (without adding a thermosetting agent), and it was found that the components of Comparative Example 1 and Comparative Example 3 could not be obtained because of the necessary components and characteristics of the double curing. Thermal curing is carried out under the above heating conditions.

The adhesive composition of the present invention (Example 3) was exposed to light at an exposure energy of 100 mJ/cm ² , and the exposure was stopped, and the DPC conversion chart at a heating temperature of 70 ° C was as shown in Fig. 5 . The heating times of A, B, C, and D were 0.5, 2.5, 3.5, and 4.0 hours, respectively. From the results of Fig. 5, it was found that the adhesive composition of the present invention had a DPC conversion of 99% under the conditions of D (heating at 70 ° C for 4 hours).

11‧‧‧ glass cover

12‧‧‧Adhesive layer

13‧‧‧LCD Module

14‧‧‧Border paint

21‧‧‧ glass cover

22‧‧‧Photocuring Complete Adhesive Composition

23‧‧‧LCD Module

24‧‧‧Black paint

121‧‧‧Adhesive layer

221‧‧‧Uncured complete adhesive composition

222‧‧‧Heat-curing complete adhesive composition

FIG. 1 is a schematic view showing the bonding of a liquid optical adhesive to a panel module having a frame structure and a glass cover.

2 is a photocuring step and thermosetting of the dual-curing adhesive composition of the present invention; Schematic diagram of the steps.

Figure 3 is a graph of DPC conversion after exposure of the adhesive composition of Example 3 at 250 mJ/cm ² .

Figure 4 is a graph showing the DPC conversion of the adhesive composition of Example 3 heated at 70 °C.

Figure 5 is a graph showing the DPC conversion of the adhesive composition of Example 3 after further exposure to 100 °C after exposure to 100 mJ/cm ² .

21‧‧‧ glass cover

22‧‧‧Photocuring Complete Adhesive Composition

23‧‧‧LCD Module

24‧‧‧Black paint

221‧‧‧Uncured complete adhesive composition

222‧‧‧Heat-curing complete adhesive composition

Claims (8)

A dual-cure adhesive composition comprising: a) a (meth) acrylate oligomer having at least one unsaturated group; b) a monofunctional monomer, a polyfunctional monomer, or a mixture thereof; a (meth) acrylate resin having an isocyanate group, wherein the (meth) acrylate resin having an isocyanate group is a (meth) acrylate oligomer having one or more isocyanate groups; d) polyester plural An alcohol resin, wherein the polyester polyol resin is a plasticizer derived from a dicarboxylic acid or anhydride and a glycol; e) an initiator; and f) having a refractive index of 1.49 or more. The adhesive composition of claim 1, wherein the monofunctional single system is selected from the group consisting of methyl methacrylate, butyl methacrylate, 2-phenoxyethyl acrylate, 2-phenoxyethyl ethoxylate Acrylate, 2-(2-ethoxyethoxy)ethyl acrylate, cyclotrimethylolpropane acetal acrylate, β-carboxyethyl acrylate, lauric acid methacrylate, isooctyl Acrylate, stearic acid methacrylate, isodecyl acrylate, isobornyl methacrylate, benzyl acrylate, 2-hydroxyethyl methacrylate phosphate, hydroxyethyl acrylate, methacrylic acid a group consisting of -2-hydroxyethyl ester and mixtures thereof; and the polyfunctional acrylate monosystem is selected from 3-hydroxy-2,2-dimethylpropionic acid 3-hydroxy-2,2- Dimethyl propyl ester diacrylate, ethoxylated 1,6-hexanediol diacrylate, dipropylene glycol diacrylate, tricyclodecane dimethanol diacrylate, propylene dipropylene glycol diacrylate, neopentyl glycol Diacrylate, propoxylated neopentyl glycol Diacrylate, ethoxylated bisphenol A dimethacrylate, 2-methyl-1,3-propanediol diacrylate, ethoxylated 2-methyl-1,3-propanediol diacrylate, 2-butyl -2-ethyl-1,3-propanediol diacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, tris(2-hydroxyethyl)isocyanuric acid triacrylate, Pentaerythritol triacrylate, ethoxylated trimethylolpropane triacrylate, propoxylated trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol tetraacrylate, pentoxide tetraol tetraacrylate, Bis-trimethylolpropane tetraacrylate, propoxypentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, tripropylene glycol dimethacrylate, 1,4-butanediol dimethacrylate, 1,6-hexyl Glycol dimethacrylate, allylated cyclohexyl dimethacrylate, isocyanuric acid dimethacrylate, ethoxylated trimethylolpropane trimethacrylate, propoxylated glycerol Trimethacrylate, tris(propyleneoxyethyl)isocyanurate, trimethylolpropane III Group consisting of acrylate and mixtures thereof. The adhesive composition of claim 1, wherein the dicarboxylic acid or acid anhydride is selected from the group consisting of succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, sebacic acid, sebacic acid, and dodecane. Diacids, isophthalic acids, terephthalic acid, cyclohexanedicarboxylic acids, phthalic acid and tetrahydrophthalic acid, and anhydrides thereof and mixtures thereof. The adhesive composition of claim 1, wherein the diol is an aliphatic diol selected from the group consisting of ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, and 1,4-butylene. Glycol, 1,5-pentanediol, 1,6-hexanediol, 2,2-dimethyl-1,3-propanediol, 1,4-cyclohexanedimethanol, 1,4-cyclohexane Diethanol, ten Glycol, dodecamethylene glycol, 2-methyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2,2,4-trimethyl-1,3- Pentandiol, diethylene glycol, triethylene glycol, tetraethylene glycol, diethylene glycol, polyethylene glycol, dipropylene glycol, polypropylene glycol, dibutylene glycol, polytetramethylene glycol, dimer diol, and mixtures thereof The group formed. The adhesive composition of claim 1, wherein the starter comprises a photoinitiator and a hot starter. The adhesive composition of claim 5, wherein the photoinitiator is selected from the group consisting of benzophenone, benzophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2, 2 -dimethoxy-1,2-diphenylethan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2,4,6-trimethylbenzhydryldiphenylphosphine oxide, and mixtures thereof The group formed. The adhesive composition of claim 5, wherein the hot starter is selected from the group consisting of benzoyl peroxide, cumene hydroperoxide, dicumyl peroxide, t-butyl hydroperoxide, and tributyl butyl peroxylate. A group consisting of enedic acid, diethyl hydrazine peroxide, lauryl peroxide, azobisisobutyronitrile, and mixtures thereof. The adhesive composition of claim 1, wherein the plasticizer is selected from the group consisting of phthalates, aliphatic dibasic acid esters, phosphate esters, polyphenyl acid esters, alkyl sulfonates, polyol esters, and rings. a group of oxygen compounds and mixtures thereof.