TWI565779B - Adhesive composition and method of fabricating the same - Google Patents

Description

Adhesive composition and method of producing the same

The present invention relates to an adhesive composition and a method for producing the same, and particularly to an adhesive composition capable of crosslinking reaction by UV irradiation, having good adhesion and antistatic effect, and a method for producing the same .

In electronic component packaging, pressure sensitive adhesive (PSA) is one of the commonly used adhesives. Pressure sensitive adhesive (PSA) is an adhesive that adheres weakly in a general environment but can adhere when exposed to a certain pressure. It has a very strong adhesive property under high pressure, and is very suitable for use in mass production of film-type products (applied to laminate between multilayer films). Moreover, the pressure sensitive adhesive itself is soft in texture and does not affect or even contribute to the improvement of the texture of the applied product. For example, when the pressure sensitive adhesive is applied to the touch panel, the user can feel a better touch.

The adhesive of pressure sensitive adhesive has the following basic properties: 1. Adhesion: the bonding force generated on the surface after being pressurized (measuring method: peeling strength), 2. cohesive force: resistance to shearing force, 3. stretchability: Deformability under low stress, 4. Elasticity: The property of material retraction after stress relaxation. The way to increase the cohesion in the gel is generally achieved by adding a hardener to bridge the polymer chains to each other. The bridging reaction is generally carried out by heating or by subjecting it to room temperature for a long period of time.

The main object of the present invention is to provide an adhesive composition and a method for manufacturing the same, which are based on energy saving, rapid process, and environmental protection, and are subjected to cross-linking reaction by UV light irradiation to form an adhesive, which has good adhesion and Antistatic effect.

According to an aspect of the invention, there is provided a method of manufacturing an adhesive comprising the steps as follows. First, a 50 to 99.9 weight percent of an acrylate monomer, 0.1 to 50 weight percent of a monomer having an epoxy group, and a solvent are provided. Wherein the acrylate single system comprises one or more monomers as shown in the following chemical formula (1):

In the formula (1), R ₁ is hydrogen (H) or methyl (CH ₃ ), and R ₂ is hydrogen (H) or a linear or branched alkyl group having 1 to 12 carbon atoms; a monomer having an epoxy group; A monomer comprising a single or a mixture of both as shown in the following chemical formulas (2), (3):

Wherein R ₃ is hydrogen (H) or methyl (CH ₃ ), R ₄ is an alkyl group, an ester group or an ether group, and R ₅ is an alkyl group or an aromatic hydroxyl group.

Next, the above acrylate monomer and epoxy group-containing monomer are dissolved in a solvent to carry out a copolymerization reaction to form a copolymer. A cationic photoinitiator is used to uniformly mix with the copolymer to form a mixture. The mixture is irradiated with ultraviolet light to subject the epoxy group-containing monomer to ring-opening polymerization to crosslink the copolymer to form an adhesive.

According to another aspect of the present invention, there is provided a composition of an adhesive comprising an acrylic copolymer and a cationic photoinitiator. Wherein, the acrylic copolymer is obtained by copolymerization of one or more acrylate monomers and one or more monomers having epoxy groups. The acrylate monomer is represented by the above formula (1), and the single system having an epoxy group includes a monomer which is a single or a combination of both as shown in the chemical formulas (2) and (3).

In order to make the above description of the present invention more apparent, the following detailed description is given as follows:

The present invention relates to an adhesive composition and a method of producing the same, which comprises a copolymer and a photoinitiator. The copolymer is obtained by copolymerization of one or more acrylate monomers and one or more epoxy group-containing monomers in a solvent, and a monomer having a polar group such as N-vinyl-2 may be further added to the solvent. Pyrrolidone (NVP). After the copolymer and the photoinitiator are mixed, the epoxy group-containing monomer is subjected to ring-opening polymerization by ultraviolet light irradiation to crosslink the copolymer to form the adhesive. The adhesive prepared according to the embodiment not only has good adhesion and antistatic effect, but also has the advantages of energy saving, rapid process, and environmental protection.

The following is an explanation of the acrylate monomer and the monomer having an epoxy group which can be applied in the examples.

<Acrylate monomer>

The acrylate monomer which can be used in the examples has the chemical structural formula (1) as follows:

Wherein R ₁ is hydrogen (H) or methyl (CH ₃ ), and R ₂ is hydrogen (H) or a linear or branched alkyl group having 1 to 12 carbon atoms.

In one embodiment, the acrylate single system may be independently selected from the group consisting of methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, and sec-butyl (meth)acrylate. Base ester, 2-ethylhexyl (meth)acrylate, isobutyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate Base ester, isooctyl (meth)acrylate, n-decyl (meth)acrylate, isodecyl (meth)acrylate, n-decyl (meth)acrylate, isodecyl (meth)acrylate A group consisting of a base ester, n-dodecyl (meth)acrylate, or a combination of two or more of the foregoing monomers.

In the examples, an acrylate monomer having an alkyl group having 1 to 12 carbon atoms may be used alone, or two or more types may be used in a mixed manner. The acrylate monomer content may range from 50 to 99.9 weight percent of the monomer component of the polymer; from 60 to 99 weight percent in another embodiment; and from 70 to 95 weight percent in still another embodiment. By using an acrylate monomer having an alkyl carbon number of 1 to 12, the glass transition temperature T _{g of the} polymer and the storage modulus can be appropriately controlled to make the adhesion more preferable.

<epoxy group monomer>

As described above, the copolymer polymer of the examples is obtained by copolymerization of one or more acrylate monomers and one or more monomers having epoxy groups. The epoxy group-containing monomer can contain an epoxy group on the side of the polymer chain, and can be subjected to ring-opening polymerization by UV light irradiation, thereby achieving the purpose of crosslinking the copolymer polymer. The adhesive of the examples was formed. The epoxy group monomer which can be used in one embodiment may be selected from one or more monomers represented by the following chemical structural formula (2) or structural formula (3):

Wherein R ₃ is hydrogen (H) or methyl (CH ₃ ), R ₄ is an alkyl group, an ester group or an ether group, and R ₅ is an alkyl group or an aromatic hydroxyl group.

In one embodiment, the epoxy group-containing monomer is, for example, Glycidyl Methacrylate (GMA), 1,2-epoxy-5-hexene (1,2-Epoxy-5). -hexene), 4-Vinyl-1-cyclohexene-1, 2-epoxide, glycidyl vinyl ether, or the like, or a mixture of two or more of the foregoing A combination of monomers.

<monomer with polar group>

The polar group-containing monomer is usually a reactive monomer containing a nitrogen atom, which can be polymerized with other monomers by a thermal initiator to form a polymer, wherein the nitrogen atom on such a polar group can be bonded to the substrate. It has better affinity and can improve the adhesion to the substrate. For example, the common nitrogen-containing monomer is 3,3-dimethyl-N-vinyl-2-pyrrolidone (3,3-dimethyl-N). -vinyl-2-pyrrolidone), 5-ethyl-N-vinyl-2-dimethyl-N-vinyl-2-pyrrolidone (5-ethyl-N-vinyl-2-dimethyl-N-vinyl-2 -pyrrolidone), but the invention is not limited thereto.

<Method of Manufacturing Adhesive>

In one embodiment, 50 to 99.9 weight percent of at least one acrylate monomer, and 0.1 to 50 weight percent of at least one epoxy group monomer are provided. Next, one or more acrylate monomers and monomers having an epoxy group are dissolved in a solvent and copolymerized to form a copolymer. In one embodiment, the copolymerization reaction is prepared as a copolymer solution having a solids content of, for example, about 20%.

Here, the solvent is, for example, ethyl acetate, acetone, methyl ethyl ketone, toluene or the like, but the present invention is not limited thereto, and the solvent selected may dissolve the acrylate monomer in a solvent. In the case where the copolymerization reaction is carried out, the synthesis can be carried out by, for example, solution polymerization, emulsion polymerization, suspension polymerization, or overall polymerization, and the present invention is not limited thereto. In one embodiment, the weight average molecular weight of the (meth) propylene based polymer used herein is from 100,000 to 5,000,000, another embodiment is from 200,000 to 4,000,000, and in another embodiment from 500,000 to 2,000,000. When the weight average molecular weight of the polymer is less than 100,000, a residual paste (adhesive residue) tends to be formed due to a decrease in the cohesive strength of the adhesive composition. On the other hand, when the weight average molecular weight exceeds 5,000,000, it tends to lower the fluidity of the polymer, and the wetting becomes insufficient, resulting in difficulty in coating engineering. The weight average molecular weight in the examples was measured by GPC (gel permeation chromatography) measurement (measured by using polystyrene as a standard to prepare a calibration curve).

After preparing the copolymer, a cationic photoinitiator is uniformly mixed with the copolymer to form a mixture. Thereafter, the mixture is irradiated with ultraviolet light, and the epoxy group-containing monomer is subjected to ring-opening polymerization to crosslink the copolymer to form an adhesive. The cationic photoinitiator is an ionic salt, and the action is to perform a ring-opening bridging reaction on the epoxy group on the acrylate copolymer to further obtain a crosslinked adhesive.

In the examples, the cationic photoinitiator is a diaromatic iodide salt, a triaromatic sulfur salt, or a dialiphatic iron salt. Since the wavelengths of photodegradation of different types of photoinitiators are also different, the wavelength range of the illumination is selected according to the photoinitiator used. In practical applications, commercial products and widely available cationic photoinitiators such as UV9380C (available from GE silicones), PC2506 (available from Polyset), SR1012 (available from Sartomer), Rhodorsil 2074 (purchased from Rhodia) ), and UVI-6974 (purchased from Dow Corporation). The ionic salt UV9380C used in the examples is a diaromatic iodonium salt photoinitiator. In addition, since the ionic salt of the UV9380C itself has electrical conductivity, when added to the adhesive composition, the resistivity of the material can be lowered to achieve an antistatic effect.

In one embodiment, an adhesive adhesion layer is formed on the film, and the method is not particularly limited. For example, the layer may be prepared by applying the above-described adhesive composition on the carrier layer and drying it. The polymerization solvent is removed and an adhesive layer is formed on the carrier layer. Further, when the adhesive sheet is prepared by coating the adhesive composition on the carrier film, one or more kinds of solvents different from the polymerization solvent may be selectively added to the composition to make the composition It can be uniformly coated on the carrier film, and an adhesive adhesion layer having a uniform film thickness can be formed after ultraviolet light irradiation. The adhesive of the embodiment can be applied as a pressure sensitive adhesive, which is produced, for example, by uniformly coating the above adhesive composition on one side or both sides of different carriers, and forming a sheet or a belt after illuminating. Pressure sensitive adhesive sheet. Wherein the aforementioned carrier film comprises a plastic film having a thickness of usually 3 to 100 μm, for example, about 5 to 50 μm, such as a polyester film, a non-woven fabric, or a porous material such as a paper sheet. Particularly in the case of a surface protective film, a plastic substrate can be used as a suitable carrier.

<Multiple sets of experimental formulas and related tests>

The present invention is further illustrated by a plurality of sets of related experimental examples, but the combination of monomers proposed in the experimental examples is not intended to limit the scope of the present invention. Any modifications and variations that may be readily made by those skilled in the art are intended to be included within the scope of the invention and the scope of the claims.

The following is a method for producing five acrylate copolymers, which are described in detail in Production Examples 1 to 5, respectively. Thereafter, in Examples 1 to 8 and Comparative Example 1, the copolymer obtained in Production Examples 1 to 5 and the photoinitiator UV9380C were mixed and irradiated to form an adhesive layer; and another Comparative Example 2 was not added with a photoinitiator. UV9380C is used to compare the effect of the adhesive layer with the experimental example of adding a photoinitiator. The adhesive layers prepared in the examples and the comparative examples were tested for adhesion.

[Manufacturing Example 1]

89 parts by weight of n-butyl acrylate (n-BA), 1 part by weight of N-vinyl-2-pyrrolidone (NVP), 10 parts by weight of glycidyl methacrylate (GMA), 150 parts by weight Ethyl acetate and 0.06 parts by weight of azobisisobutyronitrile (AIBN) were placed in a four-port reaction vessel, and the air in the reaction vessel was replaced with nitrogen, and then stirred in a nitrogen atmosphere to raise the temperature of the reaction solution to 60 ° C. 8 hours. Among them, N-vinyl-2-pyrrolidone (NVP) is a polar group-enhancing monomer, an azobisisobutyronitrile (AIBN)-based polymer reaction initiator, and ethyl acetate is a solvent. After the reaction is completed, the acrylate copolymer solution is diluted with ethyl acetate to a solid content of 20% (wherein the solid content means 20 parts by weight of the acrylate copolymer per 100 parts by weight of the acrylate polymer), and the obtained acrylic acid is obtained. The ester copolymer solution had a weight average molecular weight (Mw) of about 1 million as measured by GPC.

[Manufacturing Example 2]

94 parts by weight of n-butyl acrylate (n-BA), 1 part by weight of N-vinyl-2-pyrrolidone (NVP), 5 parts by weight of glycidyl methacrylate (GMA), 150 parts by weight Ethyl acetate and 0.06 parts by weight of azobisisobutyronitrile (AIBN) were placed in a four-port reaction vessel, and the air in the reaction vessel was replaced with nitrogen, and then stirred in a nitrogen atmosphere to raise the temperature of the reaction solution to 60 ° C. 8 hours. Among them, N-vinyl-2-pyrrolidone (NVP) is a polar group-enhancing monomer, an azobisisobutyronitrile (AIBN)-based polymer reaction initiator, and ethyl acetate is a solvent. After completion of the reaction, the acrylate copolymer solution was diluted with ethyl acetate to a solid content of 20% (solid content means 20 parts by weight of the acrylate copolymer per 100 parts by weight of the acrylate polymer), and the obtained acrylate was copolymerized. The solution had a weight average molecular weight (Mw) of about 1 million as measured by GPC.

[Manufacturing Example 3]

98 parts by weight of n-butyl acrylate (n-BA), 1 part by weight of N-vinyl-2-pyrrolidone (NVP), 1 part by weight of glycidyl methacrylate (GMA), 150 parts by weight Ethyl acetate and 0.06 parts by weight of azobisisobutyronitrile (AIBN) were placed in a four-port reaction vessel, and the air in the reaction vessel was replaced with nitrogen, and then stirred in a nitrogen atmosphere to raise the temperature of the reaction solution to 60 ° C. 8 hours. Among them, N-vinyl-2-pyrrolidone (NVP) is a polar group-enhancing monomer, an azobisisobutyronitrile (AIBN)-based polymer reaction initiator, and ethyl acetate is a solvent. After completion of the reaction, the acrylate copolymer solution was diluted with ethyl acetate to a solid content of 20% (wherein the solid content means 20 parts by weight of the acrylate copolymer per 100 parts by weight of the acrylate polymer), and the obtained acrylate was obtained. The copolymer solution had a weight average molecular weight (Mw) of about 1 million as measured by GPC.

[Manufacturing Example 4]

99 parts by weight of n-butyl acrylate (n-BA), 1 part by weight of N-vinyl-2-pyrrolidone (NVP), 150 parts by weight of ethyl acetate, and 0.06 parts by weight of azobisisobutyronitrile ( AIBN) was placed in a four-port reaction vessel, and the air in the reaction vessel was replaced with nitrogen, and then stirred in a nitrogen atmosphere, and the reaction solution was heated to 60 ° C for 8 hours. Among them, N-vinyl-2-pyrrolidone (NVP) is a polar group-enhancing monomer, an azobisisobutyronitrile (AIBN)-based polymer reaction initiator, and ethyl acetate is a solvent. After completion of the reaction, the acrylate copolymer solution was diluted with ethyl acetate to a solid content of 20% (wherein the solid content means 20 parts by weight of the acrylate copolymer per 100 parts by weight of the acrylate polymer), and the obtained acrylate was obtained. The copolymer solution had a weight average molecular weight (Mw) of about 1 million as measured by GPC.

[Manufacturing Example 5]

94 parts by weight of 2-ethylhexyl acrylate (2-EHA), 1 part by weight of N-vinyl-2-pyrrolidone (NVP), 5 parts by weight of glycidyl methacrylate (GMA), 150 A part by weight of ethyl acetate and 0.06 part by weight of azobisisobutyronitrile (AIBN) were placed in a four-port reaction vessel, and the air in the reaction vessel was replaced with nitrogen, and then stirred in a nitrogen atmosphere to raise the temperature of the reaction solution to 60. °C, the reaction was 8 hours. Among them, N-vinyl-2-pyrrolidone (NVP) is a polar group-enhancing monomer, an azobisisobutyronitrile (AIBN)-based polymer reaction initiator, and ethyl acetate is a solvent. After completion of the reaction, the acrylate copolymer solution was diluted with ethyl acetate to a solid content of 20% (wherein the solid content means 20 parts by weight of the acrylate copolymer per 100 parts by weight of the acrylate polymer), and the obtained acrylate was obtained. The copolymer solution had a weight average molecular weight (Mw) of about 1 million as measured by GPC.

The polymer composition list of the above five manufacturing examples is shown in Table (1)

Next, an acrylate polymer prepared according to the above five manufacturing examples provides an experimental example of ten sets of adhesive synthesis;

[Example 1]

The solid content 20% acrylate copolymer solution obtained in Production Example 1 was used as 100 parts by weight, and 0.6 parts by weight of a cationic photoinitiator (manufactured by GE Silicons, UV 9380C) was added thereto, and the adhesive composition was obtained after thorough mixing. . The obtained adhesive composition was applied onto a release-treated PET film, baked at 90 ° C for 5 minutes, and the solvent was evaporated to form a 20 μm adhesive layer. Next, the adhesive is formed under ultraviolet light wavelength: UVA 320-400 nm, ultraviolet light dose: 0.168 J/cm ² , ultraviolet light intensity: 1.253 W/cm ² , machine speed 10 m/min, and a pitch of 53 mm. Irradiation, making a sample for evaluation.

[Example 2]

The solid content 20% acrylate copolymer solution obtained in Production Example 2 was used as 100 parts by weight, and 0.6 parts by weight of a cationic photoinitiator (UV 9380, manufactured by GE Silicons) was added thereto, and the adhesive composition was obtained after thorough mixing. . The obtained adhesive composition was applied onto a release-treated PET film, baked at 90 ° C for 5 minutes, and the solvent was evaporated to form a 20 μm adhesive layer. Next, the adhesive is formed under ultraviolet light wavelength: UVA 320-400 nm, ultraviolet light dose: 0.168 J/cm ² , ultraviolet light intensity: 1.253 W/cm ² , machine speed 10 m/min, and a pitch of 53 mm. Irradiation, making a sample for evaluation.

[Example 3]

The solid content 20% acrylate copolymer solution obtained in Production Example 3 was used as 100 parts by weight, and 0.6 parts by weight of a cationic photoinitiator (manufactured by GE Silicons, UV 9380C) was added, and the adhesive composition was obtained after thorough mixing. . The obtained adhesive composition was applied onto a release-treated PET film, baked at 90 ° C for 5 minutes, and the solvent was evaporated to form a 20 μm adhesive layer. Next, the adhesive is formed under ultraviolet light wavelength: UVA 320-400 nm, ultraviolet light dose: 0.168 J/cm ² , ultraviolet light intensity: 1.253 W/cm ² , machine speed 10 m/min, and a pitch of 53 mm. Irradiation, making a sample for evaluation.

[Comparative Example 1]

The solid content 20% acrylate copolymer solution obtained in Production Example 4 was used as 100 parts by weight, and 0.6 parts by weight of a cationic photoinitiator (UV 9380C manufactured by GE Silicons) was added thereto, and the adhesive composition was obtained after thorough mixing. . The obtained adhesive composition was applied onto a release-treated PET film, baked at 90 ° C for 5 minutes, and the solvent was evaporated to form a 20 μm adhesive layer. Next, the adhesive is formed under ultraviolet light wavelength: UVA 320-400 nm, ultraviolet light dose: 0.168 J/cm ² , ultraviolet light intensity: 1.253 W/cm ² , machine speed 10 m/min, and a pitch of 53 mm. Irradiation, making a sample for evaluation.

[Embodiment 4]

The solid content 20% acrylate copolymer solution obtained in Production Example 5 was used as 100 parts by weight, and 0.6 parts by weight of a cationic photoinitiator (UV 9380C manufactured by GE Silicons) was added thereto, and the adhesive composition was obtained after thorough mixing. . The obtained adhesive composition was applied onto a release-treated PET film, baked at 90 ° C for 5 minutes, and the solvent was evaporated to form a 20 μm adhesive layer. Next, the adhesive is formed under ultraviolet light wavelength: UVA 320-400 nm, ultraviolet light dose: 0.168 J/cm ² , ultraviolet light intensity: 1.253 W/cm ² , machine speed 10 m/min, and a pitch of 53 mm. Irradiation, making a sample for evaluation.

[Embodiment 5]

The solid content 20% acrylate copolymer solution obtained in Production Example 2 was used as 100 parts by weight, and 1 part by weight of a cationic photoinitiator (manufactured by GE Silicons, UV 9380C) was added, and the adhesive composition was obtained after thorough mixing. . The obtained adhesive composition was applied onto a release-treated PET film, baked at 90 ° C for 5 minutes, and the solvent was evaporated to form a 20 μm adhesive layer. Next, the adhesive is formed under ultraviolet light wavelength: UVA 320-400 nm, ultraviolet light dose: 0.168 J/cm ² , ultraviolet light intensity: 1.253 W/cm ² , machine speed 10 m/min, and a pitch of 53 mm. Irradiation, making a sample for evaluation.

[Embodiment 6]

The solid content 20% acrylate copolymer solution obtained in Production Example 2 was used as 100 parts by weight, and 0.2 part by weight of a cationic photoinitiator (manufactured by GE Silicons, UV 9380C) was added thereto, and the adhesive composition was obtained after thorough mixing. . The obtained adhesive composition was applied onto a release-treated PET film, baked at 90 ° C for 5 minutes, and the solvent was evaporated to form a 20 μm adhesive layer. Next, the adhesive is formed under ultraviolet light wavelength: UVA 320-400 nm, ultraviolet light dose: 0.168 J/cm ² , ultraviolet light intensity: 1.253 W/cm ² , machine speed 10 m/min, and a pitch of 53 mm. Irradiation, making a sample for evaluation.

[Embodiment 7]

The solid content 20% acrylate copolymer solution obtained in Production Example 2 was regarded as 100 parts by weight, and 0.6 parts by weight of a cationic photoinitiator (UV 9380C manufactured by GE Silicons) was added thereto, and the adhesive composition was obtained after thorough mixing. . The obtained adhesive composition was applied onto a release-treated PET film, baked at 90 ° C for 5 minutes, and the solvent was evaporated to form a 20 μm adhesive layer. Next, the adhesive is formed under ultraviolet light wavelength: UVA 320-400 nm, ultraviolet light dose: 0.328 J/cm ² , ultraviolet light intensity: 1.293 W/cm ² , machine speed 5 m/min, and a pitch of 53 mm. Irradiation, making a sample for evaluation.

[Embodiment 8]

The solid content 20% acrylate copolymer solution obtained in Production Example 2 was used as 100 parts by weight, and 0.6 parts by weight of a cationic photoinitiator (manufactured by GE Silicons, UV 9380C) was added, and the adhesive composition was obtained after thorough mixing. . The obtained adhesive composition was applied onto a release-treated PET film, baked at 90 ° C for 5 minutes, and the solvent was evaporated to form a 20 μm adhesive layer. Next, the adhesive is formed under ultraviolet light wavelength: UVA320-400 nm, ultraviolet light dose: 0.107 J/cm ² , ultraviolet light intensity: 1.241 W/cm ² , machine speed 15 m/min, and a pitch of 53 mm. Irradiation, making a sample for evaluation.

[Comparative Example 2]

The solid content 20% acrylate copolymer solution obtained in Production Example 2 was applied onto the release-treated PET film, baked at 90 ° C for 5 minutes, and the solvent was evaporated to form a 20 μm adhesive layer. Next, the adhesive is formed under ultraviolet light wavelength: UVA 320-400 nm, ultraviolet light dose: 0.168 J/cm ² , ultraviolet light intensity: 1.253 W/cm ² , machine speed 10 m/min, and a pitch of 53 mm. Irradiation, making a sample for evaluation.

Table (2) combines the weight composition and the machine speed of the above ten experimental examples into the following:

The adhesives prepared for the above ten sets of experimental examples were subjected to various tests for their various properties. The preparation, measurement and test methods for the finished product are as follows:

<UV light irradiation>

The UV light equipment uses the F300S electrodeless lamp produced by Fusion UV SYSTEMS. The length of the lamp is 15cm (6inch), and the conveyor speed can be adjusted from 3m/min to 30m/min.

<Molecular weight measurement>

The measurement of the molecular weight was carried out using a GPC apparatus (600 Controller, manufactured by Waters Corporation). The measurement conditions were as follows: sample concentration was 0.2 wt% (THF solution); sample injection amount was 200 μl; extract was THF; flow rate was 1.0 ml/min; measurement temperature was 40 ° C column; sample column had Shodex KF803 (tube Column 1) + Shodex KF804 (column 2) + Shodex KF805 (column 3) + Shodex KF806 (column 4); the detector is a refractive index detector (RI) and the molecular weight is based on polystyrene.

<Adhesion test>

The adhesion was tested by a tensile machine (Dachang, manufactured by Hirose Instruments). The PET adhesive sheet coated with the adhesive was cut into a strip test piece of 2.5 cm width, and the release film on the test piece was peeled off, and the test piece adhesive surface was adhered to the surface of the SUS316 standard steel plate by a 2 kg rolling roller. Under the environment of temperature 23±1°C and relative humidity 50±2% RH, the 180 degree adhesion of the adhesive sheet of the sheet was measured by a tensile machine at a pulling rate of 300 mm/min.

<retention force>

The PET adhesive sheet coated with the adhesive was cut into a strip test piece of 2.5 cm width, and the release film on the test piece was peeled off, and the area of 2.5 mm × 2.5 mm was attached to the SUS316 standard steel plate, and 2 kg was applied. Roll the roller to adhere the test piece to the surface of the standard steel plate. Place it in a circulating oven at 70 °C for 20 minutes, then hang the 1KG weight for 40 minutes. The holding force refers to the time from the start of the measurement to the falling of the test code. If it has not been dropped for 40 minutes, the distance (unit: mm) of the displacement of the test piece should be recorded.

<gel fraction>

The sample was immersed in ethyl acetate for 24 hours, filtered through a sieve, and the filtered sieve was placed in an oven at 110 ° C for 1 hour, and then weighed, and the weight obtained was divided by the original sample. The weight is the gel fraction (unit: %).

<resistivity>

The surface antistatic test was carried out using a device of the type Mitsubishi Chemical Corporation Hiresta-UpMcp-HT450, which applied an external voltage of 10 to 1000 volts through two concentric annular electrodes with a planar test material in ohms/square units (Ω/□). Provide surface impedance readings.

The above ten test examples of adhesives are listed in Table (3) for various physical properties including adhesion, retention, gel fraction and electrical resistivity.

In the experimental results of the gel fraction, it can be observed that in the examples, the epoxy group is attached to the side of the polymer chain and then irradiated with UVA to achieve the crosslinking effect, and the content of the epoxy group, There is a different degree of crosslinking between the photoinitiator content and the machine speed (lighting time). It is to be noted that since Comparative Example 1 used the acrylate copolymer solution obtained in Production Example 4, Production Example 4 did not add the epoxy group-containing monomer methacrylic acid methacrylate (GMA) as in other production examples. However, in Comparative Example 2, no cationic photoinitiator was added. Therefore, the mixture obtained in Comparative Examples 1 and 2 failed to undergo ring-opening polymerization to crosslink the copolymer after the irradiation, and it can be seen from the test results of Table (3) that the adhesive formed in Comparative Examples 1 and 2 is coagulated. The glue fraction is 0, and the holding force is 1 mm (after 40 minutes, the displacement distance of the test piece is 1 mm, that is, the cohesion in the gel is relatively poor). Furthermore, since the photoinitiator is an ionic salt, it has an antistatic effect. It can be known from Comparative Example 2 that when no cationic photoinitiator is added, the surface resistivity is significantly higher than that of other experimental examples. . The resistivity is about 10 ⁹ ~ 10 ¹¹ Ω / □ that is antistatic effect, and the adhesives of Examples 1 to 8 and Comparative Example 1 have a surface resistivity of about 10 ¹¹ Ω / □ falling within the range of antistatic effect. .

Compared with the conventional process, the adhesive composition proposed in the embodiment of the present invention can achieve the bridging purpose between the long chains of the polymer by using ultraviolet light irradiation without adding a hardener or a crosslinking agent, thereby saving energy. The process is fast and efficient, and the overall process is very stable. Furthermore, the adhesive composition proposed in the examples also has good adhesion, and the use of the cationic initiator makes the adhesive have an antistatic effect, and the embodiment of the invention described above has a multi-effect function.

In conclusion, the present invention has been disclosed in the above embodiments, but it is not intended to limit the present invention. A person skilled in the art can make various changes and modifications without departing from the spirit and scope of the invention. Therefore, the scope of the invention is defined by the scope of the appended claims.

Claims (8)

A method for producing an adhesive comprising: providing 50 to 99.9 weight percent of one acrylate monomer, 0.1 to 50 weight percent of a monomer having an epoxy group, and a solvent such as the following chemical formula ( 1) shown: Wherein R ₁ is hydrogen (H) or methyl (CH ₃ ), and R ₂ is hydrogen (H) or an alkyl straight or branched chain having from 1 to 12 carbon atoms, and the single system having an epoxy group includes A monomer or a mixture of the two as shown in the following chemical formulas (2), (3): Wherein R ₃ is hydrogen (H) or methyl (CH ₃ ), R ₄ is an alkyl group, an ester group or an ether group, and R ₅ is an alkyl group or an aromatic hydroxyl group; the acrylate monomer, the epoxy group a monomer of the group is dissolved in the solvent and copolymerized to form a copolymer; a cationic photoinitiator is uniformly mixed with the copolymer to form a mixture, wherein the mixture comprises 100 parts by weight of the copolymer And 1 to 5 parts by weight of the cationic photoinitiator; and irradiating the mixture with an ultraviolet light to subject the epoxy group-containing monomer to ring-opening polymerization to crosslink the copolymer to form the adhesive Wherein the cationic photoinitiator is a diaromatic iodide salt, a triaromatic sulfur salt, or a dialiphatic iron salt. The manufacturing method according to claim 1, wherein the single system having an epoxy group is individually selected from the group consisting of Glycidyl Methacrylate (GMA) and 1,2-epoxy-5. -1,2-Epoxy-5-hexene, 4-Vinyl-1-cyclohexene-1, 2-epoxide, glycidyl vinyl ether The group formed is either a combination of two or more of the foregoing monomers. The manufacturing method according to claim 1, wherein the copolymer is formed to have a weight average molecular weight of one of 100,000 to 5,000,000. The manufacturing method according to claim 1, wherein a monomer having a polar group is further added to the solvent to copolymerize with the acrylate monomer and the epoxy group-containing monomer. A composition of an adhesive comprising: 100 parts by weight of one acrylic copolymer, which is obtained by copolymerizing an acrylate monomer and a monomer having an epoxy group, the acrylate monomer As shown in the following chemical formula (1): Wherein R ₁ is hydrogen (H) or methyl (CH ₃ ), and R ₂ is hydrogen (H) or an alkyl straight or branched chain of 1 to 12 carbon atoms; and wherein the epoxy group is single The system is attached to the chain side of the acrylic copolymer, and the single system having an epoxy group includes a single or a mixture of the monomers as shown in the following chemical formulas (2), (3): Wherein R ₃ is hydrogen (H) or methyl (CH ₃ ), R ₄ is an alkyl group, an ester group or an ether group, R ₅ is an alkyl group or an aromatic hydroxyl group; and 1 to 5 parts by weight of one cationic light The initiator, wherein the cationic photoinitiator is a diaromatic iodide salt, a triaromatic sulfur salt, or a dialiphatic iron salt. The composition of claim 5, wherein the article The single system of epoxy groups is separately selected from Glycidyl Methacrylate (GMA), 1,2-Epoxy-5-hexene, 4 a group consisting of 4-Vinyl-1-cyclohexene-1, 2-epoxide, glycidyl vinyl ether, or a mixture of two or more of the foregoing monomers combination. The composition of claim 5, wherein the acrylic copolymer has a weight average molecular weight of one of 100,000 to 5,000,000. The composition of claim 5, wherein the acrylic copolymer further comprises a monomer having a polar group to increase the adhesion of the adhesive.