KR20230081067A - Adhesive material with improved heat-and-humidity resistance and preparation method thereof - Google Patents

Abstract

The present invention relates to an adhesive material having excellent heat resistance and moisture resistance and a manufacturing method thereof. The adhesive material of the present invention relates to an adhesive material that is laminated on the surface of a substrate to improve heat resistance and moisture resistance of an adhesive film and has improved long-term reliability for the heat resistance and moisture resistance.

Description

High heat resistance, high moisture resistance adhesive material and its manufacturing method

The present invention relates to an adhesive material with high heat resistance and high moisture resistance and a method for manufacturing the same, and more particularly, has excellent heat resistance at high temperatures and improves physical properties by minimizing the deterioration of adhesive strength when the adhesive material contacts moisture. It relates to a highly moisture-resistant adhesive material and a manufacturing method thereof.

In the case of existing adhesive materials, a phenomenon in which the adhesive strength is significantly reduced when moisture penetrates can be seen. Among them, in the case of adhesive materials with strong adhesive strength, they fall more rapidly. In the case of most adhesive materials for labels, construction, and optics currently on the market, this phenomenon occurs and causes product defects. Due to this, in the case of electronic products, there is a disadvantage in that product durability is lowered and cannot be used for a long time. We are putting a lot of effort into solving this problem.

Most of the current adhesive materials increase the acid content to realize strong adhesive strength, or increase the adhesive strength by adding other tackifiers such as rosin, terpene phenol, rosin ester, and petroleum resin to the basic acrylic adhesive.

In the case of such a tackifier, although it is possible to increase the adhesive strength, many problems occur when excessively added. Excessive use of a tackifier causes a phenomenon in which the tackifier does not participate in the curing reaction and is gradually smeared onto the adherend over time. In addition, when an excessive amount of the tackifier is added to increase the adhesive strength, the adhesive strength increases, but the internal cohesive force, which is another physical property of the tape, deteriorates, causing a problem in that the adhesive material is transferred to the adhered surface. Nevertheless, since the components of this tackifier also contain a large amount of acid, the adhesive strength is less deteriorated when moisture penetrates than the adhesive material containing a relatively large amount of acid, but the deterioration intensifies over time. .

Korean Patent Publication No. 10-2017-0101785 Korean Patent Publication No. 10-2021-0020328

The present invention is to solve the problems of the prior art described above, and one object of the present invention is to provide an adhesive material having excellent adhesive strength while containing a small amount of acid.

Another object of the present invention is to provide an adhesive material that maintains a certain level or more of adhesive strength for a long time even when moisture penetrates, by overcoming the disadvantage of local deterioration of adhesive strength when moisture penetrates, which is a problem of general strong adhesive materials.

Another object of the present invention is to provide a method for producing a highly heat-resistant and highly moisture-resistant adhesive material comprising the step of polymerizing a high molecular weight acrylic copolymer having a number average molecular weight of 1,000,000 or more.

One aspect of the present invention for solving the above problems is,

(a) an acrylic copolymer obtained by copolymerizing 15 to 20 parts by weight of butyl acrylate, 1 to 5 parts by weight of benzyl acrylate, 1 to 2 parts by weight of 2-hydroxyethyl acrylate, and 0.5 to 3 parts by weight of acrylic acid: and

(b) an acrylic tackifying resin obtained by copolymerizing 25 to 29 parts by weight of cyclohexyl methacrylate, 2 to 4 parts by weight of 2-hydroxyethyl acrylate, and 0.1 to 1 part by weight of isopropane diisocyanate; and

(c) It relates to a high heat resistance and high moisture resistance adhesive material characterized in that it contains 2 to 3% by weight of rosin ester.

In the present invention, the acrylic copolymer may have a number average molecular weight in the range of 1 million to 2 million.

The adhesive material of the present invention may further include an isocyanate-based crosslinking agent, an epoxy-based crosslinking agent, or an aziridine-based crosslinking agent.

Another aspect of the present invention relates to a pressure-sensitive adhesive layer formed of the pressure-sensitive adhesive material and an adhesive film including the pressure-sensitive adhesive layer.

Another aspect of the present invention is

An acrylic monomer composed of 15 to 20 parts by weight of butyl acrylate, 1 to 5 parts by weight of benzyl acrylate, 1 to 2 parts by weight of 2-hydroxyethyl acrylate, and 0.5 to 3 parts by weight of acrylic acid; 0.1 to 1 part by weight of a 1',1'-azobis(cyclohexanecarbonitrile) thermal initiator; and introducing a solvent composed of 20 to 30 parts by weight of acetone and 40 to 50 parts by weight of ethyl acetate into a reactor, and proceeding with a polymerization reaction for 8 hours while raising the temperature to 60 ° C.;

Obtaining a high molecular weight acrylic copolymer by performing natural deterioration aging at a temperature of 60 ° C for 8 hours after completion of the polymerization reaction;

25 to 29 parts by weight of cyclohexyl methacrylate, 2 to 4 parts by weight of 2-hydroxyethyl acrylate; 1 to 5 parts by weight of a 2,2'-azobis(methylbutyronitrile) thermal initiator; and adding 1 to 2 parts by weight of mercaptanethanol and 20 to 25 parts by weight of toluene to a reactor and synthesizing an acrylic oligomer for 8 hours while raising the temperature to 110° C.;

Subsequently, slowly adding 0.1 to 1 part by weight of isopropanol diisocyanate in a fixed amount for 30 minutes at 60° C. to obtain an acrylic tackifying resin;

preparing an adhesive material by blending 2 to 30 parts by weight of an acrylic tackifying resin and 2 to 3 parts by weight of a rosin ester tackifying resin based on 100 parts by weight of the obtained acrylic copolymer;

It relates to a method for producing an adhesive material comprising the step of mixing 1 to 2 parts by weight of an isocyanate-based curing agent with the obtained adhesive material and coating it on a substrate.

Unlike general adhesive materials, the adhesive material of the present invention contains very little acid, but its adhesive strength is equal to or higher than that of products containing a lot of acid. It has adhesive strength equal to or greater than that of

The adhesive material of the present invention has excellent moisture resistance to the extent that the deterioration of adhesive strength is less than 20% when moisture penetrates in a sheet state or in a state attached to an adherend, and uses an acrylic copolymer having a number average molecular weight of 1 million or more as a base, The acrylic tackifying resin has a hydroxyl group, which is the origin of crosslinking, and participates in the reaction, and is characterized by considerably excellent heat resistance at high temperatures.

According to the present invention, it is possible to provide an adhesive material that does not deteriorate shear strength while increasing initial tack and adhesion.

In addition, according to the present invention, it is possible to provide high cohesive strength in which cohesive failure does not occur even at a high temperature of 150 ° C. or higher by adding an acrylic tackifying resin containing a sufficient hydroxyl group and adding an isocyanate-based curing agent.

Hereinafter, embodiments of the present invention will be described in more detail. In addition, in describing the present invention, a detailed description of a related general-purpose function or configuration will be omitted.

As used herein, the terms "comprising" and "comprising" are inclusive or open-ended and do not exclude additional, unrecited members, elements or process steps.

The term “acrylate” herein refers to either or both “acrylate” and “methacrylate”.

As used herein, the term “acrylic” refers to either or both “acrylic” and “methacrylic”.

One aspect of the present invention, (a) by copolymerizing 15 to 20 parts by weight of butyl acrylate, 1 to 5 parts by weight of benzyl acrylate, 1 to 2 parts by weight of 2-hydroxyethyl acrylate, 0.5 to 3 parts by weight of acrylic acid An acrylic copolymer consisting of: and

(b) an acrylic tackifying resin obtained by copolymerizing 25 to 29 parts by weight of cyclohexyl methacrylate, 2 to 4 parts by weight of 2-hydroxyethyl acrylate, and 0.1 to 1 part by weight of isopropane diisocyanate; and

(c) It relates to a high heat resistance and high moisture resistance adhesive material characterized in that it contains 2 to 3% by weight of rosin ester.

The adhesive material of the present invention may further include an isocyanate-based curing agent. It is preferable to add 1 to 2 parts by weight of the isocyanate-based curing agent based on 100 parts by weight of the adhesive material. When the amount of isocyanate-based curing agent is less than 1 part by weight with respect to 100 parts by weight of the adhesive material, the crosslinking density of the adhesive material is low, causing swelling and bubbles of the adhesive material under severe conditions (high temperature and high humidity). If it exceeds 2.0 parts by weight, the adhesive material The crosslinking density of is too high, and lifting with the substrate may occur under harsh conditions (high temperature, high humidity).

The adhesive material of the present invention is synthesized with acid-free acrylic oligomer instead of adding an excessive amount of acid or adding a tackifying resin such as rosin, rosin ester, terpene phenol, or petroleum resin to realize strong adhesive strength. Realized strong adhesion. Therefore, it is possible to overcome the problem of an adhesive material containing a lot of acid, in which the adhesive strength drops by more than 90% when in contact with moisture, and maintain the adhesive strength at 80% or more even when in contact with water.

The adhesive material of the present invention maintained its adhesive strength even in hot water at 80° C. by adding a small amount of rosin ester, a tackifying resin having a low swallowing point, in a heat-resistant and moisture-resistant state. The reason for adding a small amount of rosin ester is to prevent the adhesive sheet from being rapidly peeled off in 80 ° C water by realizing additional initial adhesion (TACK) as the rosin ester rises to the adhesive surface.

In the present invention, the acrylic copolymer can be produced by a known polymerization method (bulk polymerization, solution polymerization, emulsion polymerization, suspension polymerization, etc.) using a known polymerization initiator or the like. In order to obtain an adhesive material having good water resistance, it is preferable to employ a solution polymerization method or bulk polymerization method. For example, it may be prepared by a solution polymerization method, and may be prepared by carrying out a polymerization temperature of about 50 ℃ to 140 ℃. Thermal initiators used in the polymerization include azo-based polymerization initiators such as azobisisobutyronitrile and azobisisovaleronitrile, peroxides such as benzoyl peroxide, di-t-butyl peroxide, and lauryl peroxide A polymerization initiator may be used, and one or a mixture of two or more of the above may be used.

The molecular weight of the acrylic copolymer is usually 50,000 to 2,000,000, preferably 1,000,000 to 2,000,000 in terms of weight average molecular weight (in terms of polystyrene) by gel permeation chromatography (GPC).

In the present invention, as the crosslinking agent, the acrylic tackifying resin contains isopropane diisocyanate, so basic curing proceeds, but in order to realize additional physical properties, it is more advantageous to use an isocyanate crosslinking agent, an epoxy crosslinking agent, and an aziridine crosslinking agent in combination. do.

As the isocyanate-based crosslinking agent, for example, toluene diisocyanate, naphthalene-1,5-diisocyanate, hexamethylene diisocyanate, diphenylmethane diisocyanate, xylene diisocyanate, trimethylolpropane-modified toluene diisocyanate, etc. are used, and epoxy As the crosslinking agent, bisphenol A type epoxy resin, 1,3-bis(n,n-diglycidyl-aminomethyl)cyclohexane, n,n,n`,-tetraglycidyl-m-xylenediamine, 1 Diglycidyl of ,4-butanediol, etc. can be used. As the aziridine-based crosslinking agent, trimethylolpropane tris(2-methyl-1-aziridine propionate, trimethylolpropane tris(b-n-aziridinyl)propionate, pentaerythritol tris{3-(1-aziridinyl) propionate}, pentaerythritol tris(2-methyl-1-aziridine propionate), etc. can be used, and it is preferable to use toluene diisocyanate.

The crosslinking agent is preferably included in an amount of 0.1 to 1 part by weight based on 100 parts by weight of the acrylic copolymer. If the content is less than 0.1 part by weight, sufficient cohesive force is not imparted, resulting in deterioration in high-speed peelability. There is a problem in that the adhesive property is lowered and the wettability to the adherend is greatly reduced.

<Other additives>

In addition, the adhesive material of the present invention further includes other additives such as acrylic low molecular weight materials, epoxy resins, curing agents, UV stabilizers, antioxidants, colorants, reinforcing agents, fillers, plasticizers, surfactants, foaming agents, antifoaming agents and organic salts, as needed. can do. The adhesive material of the present invention can be uniformly coated only when the functional group crosslinking reaction of the crosslinking agent hardly occurs during the mixing process for forming the adhesive layer. When such a coating operation is completed and a drying and aging process is performed, a cross-linked structure is formed to obtain an elastic and cohesive pressure-sensitive adhesive layer. At this time, due to the strong cohesive force of the adhesive material, the adhesive physical properties such as durability and moisture resistance of the adhesive product are improved.

In general, the performance of an adhesive material can be applied by tack, adhesion, and shear strength. The initial adhesive force is related to the glass transition temperature (Tg) of the polymer constituting the adhesive material, and the adhesive force is related to the glass transition temperature and cohesive force of the polymer. The cohesive force is a force that appears between the molecules of the adhesive material when the adhesive material is applied to the adherend. If the intermolecular cohesive force is high, interfacial destruction of the adhesive material occurs, and if it is low, cohesive failure occurs, leaving residue on the adherend. It is ideal to design the adhesive material so that interfacial failure occurs during peeling.

[Adhesive Layer]

In another aspect of the present invention, an adhesive material having a structure in which an adhesive layer formed by thermally curing the adhesive material is laminated on one side or both sides of a substrate is provided. The substrate may have a thickness of about 4 μm to about 500 μm, and the pressure-sensitive adhesive layer may have a thickness of about 10 μm to about 100 μm.

It is preferable to form an adhesive layer under the following conditions. After applying the adhesive material of the present invention on a base material or on the release treated surface of a release sheet and sticking the release sheet on the coating film formed under the above conditions, it is usually 3 days or more, preferably 7 to 10 days at 5 to 60°C, Aged in an environment of 30-70% RH. When crosslinking is performed under the aging conditions as described above, a crosslinked product (network polymer) can be efficiently formed.

As a method of applying the adhesive material, a method of coating and drying to a predetermined thickness by a known method, for example, a spin coating method, a knife coating method, a roll coating method, a bar coating method, a blade coating method, a die coating method, or a gravure coating method. can be used.

[adhesive sheet]

The pressure-sensitive adhesive sheet of the present invention has a pressure-sensitive adhesive layer made from the above-mentioned pressure-sensitive adhesive material. The pressure-sensitive adhesive sheet includes, for example, a double-sided pressure-sensitive adhesive sheet having only the pressure-sensitive adhesive layer, a double-sided pressure-sensitive adhesive sheet having a base material and the pressure-sensitive adhesive layer formed on both sides of the base material, and a single-sided pressure-sensitive adhesive sheet having a base material and the pressure-sensitive adhesive layer formed on one side of the base material. , and a pressure-sensitive adhesive sheet in which a release sheet is affixed on the surface of the pressure-sensitive adhesive layer of those pressure-sensitive adhesive sheets that is not in contact with the base material.

Examples of the substrate and release sheet include polycarbonate (PC), polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), and polyethylene (PE). , polypropylene (PP), ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, acrylonitrile-butadiene-styrene copolymer (ABS), polyamide (nylon), polyimide, polyvinyl chloride (PVC), etc. A plastic film can be mentioned. Moreover, glass, paper, a nonwoven fabric, etc. are mentioned as a base material.

<Use>

The adhesive material of the present invention described above is suitable for various uses. For example, it is preferably used for optical members such as optical films. Examples of such an optical film include a polarizing plate, a retardation plate for coloration prevention, an optical compensation film such as a viewing angle magnifying film for improving the viewing angle of a liquid crystal display, a luminance enhancing film for increasing the contrast of a display, and further laminated ones thereof.

In the present invention, the form of the pressure-sensitive adhesive layer formed of an adhesive material, the form of an optical member formed by forming the pressure-sensitive adhesive layer such as an optical film, the form of the form that the said optical film is a polarizing plate, or the form of the said optical member in a liquid crystal display device, organic A form applied to an image display device such as an EL display device, a plasma display (PDP), a micro LED display, a curved display or a flexible display may also be provided.

Another aspect of the present invention relates to a method for manufacturing the adhesive material by coating the above-described adhesive material on a substrate. In the present invention, an acrylic monomer consisting of 15 to 20 parts by weight of butyl acrylate, 1 to 5 parts by weight of benzyl acrylate, 1 to 2 parts by weight of 2-hydroxyethyl acrylate, and 0.5 to 3 parts by weight of acrylic acid; 0.1 to 1 part by weight of a 1',1'-azobis(cyclohexanecarbonitrile) thermal initiator; and introducing a solvent composed of 20 to 30 parts by weight of acetone into a reactor, and proceeding with a polymerization reaction for 8 hours while raising the temperature to 60 ° C.;

Polymerizing a polymeric adhesive material having a number average molecular weight of 1 million or more by performing natural deterioration aging at an outdoor temperature of 60 ° C for 8 hours after completion of the reaction;

An acrylic oligomer composed of 25 to 29 parts by weight of cyclohexyl methacrylate and 2 to 4 parts by weight of 2-hydroxyethyl acrylate; 1 to 5 parts by weight of a 2,2'-azobis(methylbutyronitrile) thermal initiator; And a solvent consisting of 1-2 parts by weight of mercaptanethanol and 20-25 parts by weight of toluene was introduced into the reactor, and oligomer synthesis was performed for 8 hours while the temperature was raised to 110 ° C., and 0.1-1 part by weight of isopropanol diisocyanate at 60 ° C. Injecting slowly and quantitatively for a minute;

Adding 2 to 30 parts by weight of an acrylic tackifying resin to the completed adhesive material having a number average molecular weight of 1 million or more and adding 2 to 3 parts by weight of a rosin ester tackifying resin;

It relates to a method for producing an adhesive material comprising the step of mixing 1 to 2 parts by weight of an isocyanate-based curing agent with the finished adhesive material and coating it on a substrate. It will be described in more detail. First, after polymerizing the acrylic monomer, thermal initiator, and solvent, synthesizing an acrylic tackifying resin containing the acrylic monomer, solvent, thermal initiator, and isopropyl diisocyanate and adding it to the polymeric adhesive material, , A rosin ester-based tackifying resin may be mixed to form a pressure-sensitive adhesive composition, and then the pressure-sensitive adhesive layer may be coated. The method of forming the adhesive layer on the substrate as described above is not particularly limited, and for example, a method of applying and drying an adhesive using a bar coater or the like directly on the surface of the base fabric substrate, applying the adhesive to the surface of a peelable substrate and drying After that, a method of transferring and aging the pressure-sensitive adhesive layer formed on the surface of the peelable substrate to the surface of the substrate may be applied.

The adhesive material of the present invention primarily contains an isocyanate group in an acrylic tackifier, so a crosslinking reaction proceeds without additionally adding another curing agent. A curing agent of may be additionally added to improve substrate adhesion and cohesion.

The isocyanate-based, epoxy-based, aziridine-based curing agent preferably includes 0.01 to 10 parts by weight of an isocyanate-based crosslinking agent, based on 100 parts by weight of the copolymer and acrylic oligomer compound mixed adhesive material, and 0.01 to 1 part by weight of the epoxy and aziridine-based crosslinking agent. It is desirable to do In the case of the isocyanate-based crosslinking agent, when it exceeds 10 parts by weight, the pot life is not shown, so the adhesive material curing agent mixture can be crosslinked in a blended state before forming a coating film.

Hereinafter, the present invention will be described in more detail by way of examples. However, the following examples are for illustrative purposes only, and the scope of the present invention is not construed as being limited by the examples. All parts and % in each example are by weight. The room temperature leaving conditions, which are not particularly specified below, are all 23 ° C. and 65% RH.

Example :

Example 1

(Manufacture of acrylic copolymer)

After nitrogen gas was filled in a reactor equipped with a stirrer, thermometer, reflux condenser and nitrogen inlet pipe, 15 parts by weight of butyl acrylate, 1 part by weight of benzyl acrylate, 1 part by weight of 2-hydroxyethyl acrylate, 0.5 part by weight of acrylic acid an acrylic monomer composed of; 0.1 part by weight of a 1',1'-azobis(cyclohexanecarbonitrile) thermal initiator; And a solvent consisting of 20 parts by weight of acetone was introduced into the reactor, and the polymerization reaction was performed for 8 hours while the temperature was raised to 60 ° C. After the polymerization reaction was completed, natural aging was performed at a temperature of 60 ° C. for 8 hours to obtain a high molecular weight acrylic copolymer. obtained. Then 25 parts by weight of cyclohexyl methacrylate, 2 parts by weight of 2-hydroxyethyl acrylate; 1 part by weight of a 2,2'-azobis(methylbutyronitrile) thermal initiator; And 1 part by weight of mercaptanethanol and 20 parts by weight of toluene were introduced into the reactor to synthesize an acrylic oligomer for 8 hours while raising the temperature to 110 ° C. Then, 0.1 part by weight of isopropanol diisocyanate was slowly and quantitatively added at 60 ° C. for 30 minutes to apply acrylic tackifier. got the resin Next, 2 parts by weight of an acrylic tackifying resin and 2 to 3 parts by weight of a rosin ester tackifying resin were blended to prepare a pressure-sensitive adhesive based on 100 parts by weight of the obtained acrylic copolymer, and 1 part by weight of an isocyanate-based curing agent was mixed with the obtained pressure-sensitive adhesive and coated on a substrate to prepare an adhesive material.

(Manufacture of Acrylic Tackifying Resin)

An acrylic oligomer composed of 25 parts by weight of cyclohexyl methacrylate, 2 parts by weight of 2-hydroxyethyl acrylate, and 0.1 part by weight of isopropane diisocyanate; 1 part by weight of a 2,2'-azobis(methylbutyronitrile) thermal initiator; And an acrylic tackifying resin composed of a solvent consisting of 1 part by weight of mercaptanethanol and 65 parts by weight of toluene was prepared.

(Manufacture of adhesive materials)

An adhesive material containing 30 parts by weight of an acrylic tackifying resin and 3 parts by weight of a rosin ester at 80° C. was prepared based on 100 parts by weight of the prepared acrylic copolymer.

(Formulation process)

1 part by weight of toluene diisocyanate was added to 100 parts by weight of the acrylic adhesive material prepared above, diluted to an appropriate concentration in consideration of coating properties, mixed evenly, coated on a substrate, and then a uniform adhesive layer having a thickness of 25 μm was prepared did

(Adhesive material manufacturing process)

After adhesive processing of the prepared adhesive layer on a polyester plain weave fabric, it was stored for 4 days at a temperature of 40° C. and a relative humidity of 50% for sufficient aging process. The adhesive material obtained as described above was cut into appropriate sizes and used for performance evaluation.

Example 2

After nitrogen gas was filled in a reactor equipped with a stirrer, thermometer, reflux condenser and nitrogen inlet pipe, 15 parts by weight of butyl acrylate, 6 parts by weight of benzyl acrylate, 2.5 parts by weight of 2-hydroxyethyl acrylate, 2 parts by weight of acrylic acid an acrylic monomer composed of; 0.5 parts by weight of a 1',1'-azobis(cyclohexanecarbonitrile) thermal initiator; And a solvent consisting of 45 parts by weight of acetone was introduced into the reactor, and the polymerization reaction proceeded for 8 hours while raising the temperature to 60 ℃. After completion of the polymerization reaction, natural aging was performed at a temperature of 60° C. for 8 hours to obtain a high molecular weight acrylic copolymer. Then 27 parts by weight of cyclohexyl methacrylate, 3 parts by weight of 2-hydroxyethyl acrylate; 3 parts by weight of a 2,2'-azobis(methylbutyronitrile) thermal initiator; And 1.5 parts by weight of mercaptanethanol and 24 parts by weight of toluene were introduced into the reactor to synthesize an acrylic oligomer for 8 hours while raising the temperature to 110 ° C. Then, 0.5 parts by weight of isopropanol diisocyanate was slowly and quantitatively added at 60 ° C. for 30 minutes to apply an acrylic tackifier. got the resin Next, based on 100 parts by weight of the obtained acrylic copolymer, 20 parts by weight of an acrylic tackifying resin and 2.5 parts by weight of a rosin ester tackifying resin were blended to prepare a pressure-sensitive adhesive, and 1.5 parts by weight of an isocyanate-based curing agent was mixed with the obtained pressure-sensitive adhesive. was coated on to prepare an adhesive material.

Example 3

After nitrogen gas was filled in a reactor equipped with a stirrer, thermometer, reflux condenser and nitrogen inlet tube, 12 parts by weight of butyl acrylate, 10 parts by weight of 2-ethylhexyl acrylate, 8 parts by weight of benzyl acrylate, 2-hydroxy an acrylic monomer composed of 3 parts by weight of ethyl acrylate and 3 parts by weight of acrylic acid; 1 part by weight of a 1',1'-azobis(cyclohexanecarbonitrile) thermal initiator; and introducing a solvent composed of 50 parts by weight of acetone into a reactor, and proceeding with a polymerization reaction for 8 hours while raising the temperature to 60° C.; After completion of the polymerization reaction, natural aging was performed at a temperature of 60° C. for 8 hours to obtain a high molecular weight acrylic copolymer. Then 29 parts by weight of cyclohexyl methacrylate, 4 parts by weight of 2-hydroxyethyl acrylate; 5 parts by weight of a 2,2'-azobis(methylbutyronitrile) thermal initiator; And 2 parts by weight of mercaptanethanol and 25 parts by weight of toluene were introduced into the reactor to synthesize an acrylic oligomer for 8 hours while raising the temperature to 110 ° C. Then, 1 part by weight of isopropanol diisocyanate was slowly and quantitatively added at 60 ° C. for 30 minutes to apply acrylic tackifier. got the resin Next, with respect to 100 parts by weight of the obtained acrylic copolymer, 20 parts by weight of an acrylic tackifying resin and 10 parts by weight of a rosin ester tackifying resin were blended to prepare a pressure-sensitive adhesive, and 2 parts by weight of an isocyanate-based curing agent was mixed with the obtained pressure-sensitive adhesive to the base material An adhesive material was prepared by coating.

Comparative Example 1

An acrylic copolymer composed of 18 parts by weight of butyl acrylate, 3 parts by weight of benzyl acrylate, 1.5 parts by weight of 2-hydroxyethyl acrylate, and 8 parts by weight of acrylic acid; 0.5 parts by weight of a benzyl peroxide thermal initiator; and 650 parts by weight of ethyl acetate. After the adhesive layer prepared by blending 1 part by weight of toluene diisocyanate to a general strong adhesive material composed of a solvent consisting of 650 parts by weight of ethyl acetate is adhered to a polyester plain weave fabric, 40 ℃ temperature and 50% for sufficient aging process. It was stored for 4 days at a relative humidity of .

Comparative Example 2

An acrylic copolymer composed of 20 parts by weight of butyl acrylate, 5 parts by weight of benzyl acrylate, 2 parts by weight of 2-hydroxyethyl acrylate, and 6 parts by weight of acrylic acid; An adhesive layer prepared by mixing 1 part by weight of toluene diisocyanate with a strong adhesive material containing 1 part by weight of benzyl peroxide thermal initiator and 20 parts by weight of common rosin, rosin ester, terpene phenol, and petroleum resin is adhered to polyester plain weave fabric. After processing, it was stored for 4 days at a temperature of 40 ° C and a relative humidity of 50% for sufficient aging process.

Comparative Example 3

An acrylic copolymer composed of 10 parts by weight of butyl acrylate, 5 parts by weight of 2-ethylhexyl acrylate, 1 part by weight of benzyl acrylate, 1.5 parts by weight of 2-hydroxyethyl acrylate, and 4 parts by weight of acrylic acid; An adhesive layer prepared by mixing 1 part by weight of toluene diisocyanate with a strong adhesive material containing 0.6 parts by weight of benzyl peroxide thermal initiator and 20 parts by weight of common rosin, rosin ester, terpene phenol, and petroleum resin is adhered to polyester plain weave fabric. After processing, it was stored for 4 days at a temperature of 40 ° C and a relative humidity of 50% for sufficient aging process.

Comparative Example 4

An acrylic copolymer composed of 11 parts by weight of butyl acrylate, 5 parts by weight of 2-ethylhexyl acrylate, 3 parts by weight of methyl acrylate, 1 part by weight of 2-hydroxyethyl acrylate, and 7 parts by weight of acrylic acid; An adhesive layer prepared by mixing 1 part by weight of toluene diisocyanate with a strong adhesive material containing 1 part by weight of benzyl peroxide thermal initiator and 30 parts by weight of general rosin, rosin ester, terpene phenol, and petroleum resin is adhered to polyester plain weave fabric. After processing, it was stored for 4 days at a temperature of 40 ° C and a relative humidity of 50% for sufficient aging process.

test example

As an evaluation of the characteristics of the adhesive materials prepared in Examples 1 to 3 and Comparative Examples 1-4, the following sheet moisture resistance, adhesive strength, hot water resistance, and cohesive strength were measured by the following methods, and the results are shown in the table below. 1.

1) Sheet moisture resistance: After the samples were left for 72 hours under conditions of 85° C. and 85% relative humidity, the change in adhesive strength was measured according to KST 1028. The unit is g/25mm.

2) Adhesion: The samples were attached to the adherend, and after 30 minutes, the adhesive force was measured according to KST 1028. The unit is g/25mm.

3) Moisture resistance to hot water: After the sample was attached to the adhered plate, left for 1 hour, left in hot water at 80 ° C for 30 minutes, and then left for 4 hours, the sample adhered to the adhered plate was measured according to KST 1028. The unit is g/25mm.

4) Cohesion measurement: After attaching the sample to the adherend plate, it was measured according to KST 1028.

heat resistance moisture resistance adhesion initial adhesion Sheet
moisture resistance heat-resistant bath
moisture resistance cohesion Example 1 Great Great 2400 g/f 2200 g/f 2100 g/f more than 1 hour Example 2 Great Great 2650 g/f 2430 g/f 2370 g/f more than 1 hour Example 3 Great Great 2100 g/f 2020 g/f 1780 g/f more than 1 hour Comparative Example 1 Great error 2350 g/f 150 g/f 3 g/f more than 1 hour Comparative Example 2 error error 2420 g/f 820 g/f 120 g/f cohesive destruction Comparative Example 3 Great error 2120 g/f 730 g/f 150 g/f more than 1 hour Comparative Example 4 error error 2020 g/f 110 g/f 20 g/f more than 1 hour

As confirmed through the results of Table 1, looking at the thermal stability measurement values of Example 1, it can be confirmed that the dimensional change due to heat is extremely small and has excellent thermal stability. In contrast, in the case of Comparative Examples 1 and 2, it was confirmed that thermal stability, that is, heat resistance was inferior.

Although the present invention has been described in detail with specific examples above, it is not limited to the above examples, and various modifications and modifications can be made by those skilled in the art within the scope of not departing from the spirit of the present invention. Change is possible. Such modifications and variations are to be regarded as falling within the scope of this invention and the appended claims.

Claims (7)

(a) an acrylic copolymer obtained by copolymerizing 15 to 20 parts by weight of butyl acrylate, 1 to 5 parts by weight of benzyl acrylate, 1 to 2 parts by weight of 2-hydroxyethyl acrylate, and 0.5 to 3 parts by weight of acrylic acid: and
(b) an acrylic tackifying resin obtained by copolymerizing 25 to 29 parts by weight of cyclohexyl methacrylate, 2 to 4 parts by weight of 2-hydroxyethyl acrylate, and 0.1 to 1 part by weight of isopropane diisocyanate; and
(c) A highly heat-resistant, highly moisture-resistant adhesive material comprising 2 to 3% by weight of rosin ester.
The highly heat-resistant and highly moisture-resistant adhesive material according to claim 1, wherein the acrylic copolymer has a number average molecular weight in the range of 1 million to 2 million.
The highly heat-resistant and highly moisture-resistant adhesive material according to claim 1, wherein the adhesive material further comprises an isocyanate-based crosslinking agent, an epoxy-based crosslinking agent, or an aziridine-based crosslinking agent.
An adhesive layer formed from the adhesive material according to any one of claims 1 to 3.
An adhesive film comprising the pressure-sensitive adhesive layer for an optical film according to claim 4 and a base material provided on one side of the pressure-sensitive adhesive layer.
An acrylic monomer composed of 15 to 20 parts by weight of butyl acrylate, 1 to 5 parts by weight of benzyl acrylate, 1 to 2 parts by weight of 2-hydroxyethyl acrylate, and 0.5 to 3 parts by weight of acrylic acid; 0.1 to 1 part by weight of a 1',1'-azobis(cyclohexanecarbonitrile) thermal initiator; and introducing a solvent composed of 20 to 30 parts by weight of acetone into a reactor and conducting a polymerization reaction for 8 hours while raising the temperature to 60° C.;
Obtaining a high molecular weight acrylic copolymer by performing natural deterioration aging at a temperature of 60 ° C. for 8 hours after completion of the polymerization reaction;
25 to 29 parts by weight of cyclohexyl methacrylate, 2 to 4 parts by weight of 2-hydroxyethyl acrylate; 1 to 5 parts by weight of a 2,2'-azobis(methylbutyronitrile) thermal initiator; and adding 1 to 2 parts by weight of mercaptanethanol and 20 to 25 parts by weight of toluene to a reactor and synthesizing an acrylic oligomer for 8 hours while raising the temperature to 110° C.;
Subsequently, slowly adding 0.1 to 1 part by weight of isopropanol diisocyanate in a fixed amount for 30 minutes at 60° C. to obtain an acrylic tackifying resin;
preparing an adhesive material by blending 2 to 30 parts by weight of an acrylic tackifying resin and 2 to 3 parts by weight of a rosin ester tackifying resin based on 100 parts by weight of the obtained acrylic copolymer;
A method for producing a highly heat-resistant, highly moisture-resistant adhesive material comprising the step of mixing 1 to 2 parts by weight of an isocyanate-based curing agent with the obtained adhesive material and coating it on a substrate.
7. The method of claim 6, wherein in the natural deterioration aging step, the acrylic copolymer is aged to a molecular weight of 1,000,000 or more.