KR101082635B1 - Aqueous Pressure Sensitive Adhesive Of Acrylic Emulsion-type Having Superior Adhesion And Storage Stability And Preparation Method Thereof - Google Patents

Abstract

The present invention relates to an aqueous acrylic emulsion pressure sensitive adhesive having excellent adhesive strength and storage stability and a method for preparing the same, and more particularly, to an aqueous acrylic emulsion pressure sensitive adhesive, i) alkyl acrylate, alkyl methacrylate, or a mixture thereof 60 to 90 weight %, Ii) 5 to 30% by weight of allyl ester, vinyl ester, unsaturated acetate or mixtures thereof, i) 0.5 to 5% by weight of unsaturated carboxylic acid, hydroxyl-containing unsaturated monomer or mixture thereof, i) 0.1 to 0.1 to epoxy group-containing unsaturated monomer 3 parts by weight and iii) 100 parts by weight of a monomer mixture consisting of 0.1 to 3% by weight of a crosslinking agent; And iii) 5 to 30 parts by weight of a tackifier; and an aqueous acrylic emulsion pressure sensitive adhesive having excellent adhesive strength and storage stability, and a method for producing the same, comprising an acrylic emulsion prepared by polymerization.

The present invention has the effect of providing an aqueous acrylic emulsion pressure-sensitive adhesive and a method for preparing the same, while maintaining the adhesion and storage stability of the oil-based adhesive agent does not cause sick house syndrome.

Acrylic, emulsion, pressure sensitive adhesive, crosslinking agent, tackifier, emulsion, storage stability

Description

Aqueous Pressure Sensitive Adhesive Of Acrylic Emulsion-type Having Superior Adhesion And Storage Stability And Preparation Method Thereof}

The present invention relates to an aqueous acrylic emulsion pressure-sensitive adhesive having excellent adhesive strength and storage stability, and a method for preparing the same, and more particularly, to an aqueous acrylic emulsion pressure-sensitive adhesive having a pressure-sensitive adhesive strength and storage stability and not causing a sick house syndrome. It is about.

Existing oil-based adhesive releases residual solvent in the air for a long time after construction, causing symptoms such as headache, irritation of eyes, cough, itching, dizziness, fatigue, and decreased concentration in the people living in the building. Exposure causes problems with Sick House Syndrome, which can cause respiratory illness, heart disease, and cancer. For this reason, the demand for eco-friendly products is increasing, but at present, the aqueous emulsion pressure-sensitive adhesives are not being replaced quickly because they do not reach the physical properties as oil-based adhesives.

The decrease in the physical properties of such an aqueous emulsion pressure sensitive adhesive is caused by various additives added during emulsion polymerization and post-treatment process, and the surfactant which gives stability to latex is present on the surface of the adhesive resin after coating, thereby affecting the adhesion to the adhesive. And impairs the cohesion between the latex particles in the pressure-sensitive adhesive during coating to reduce cohesion.

In addition, the wetting agent that improves the wettability on the surface of the silicone release paper by lowering the surface tension of the pressure-sensitive adhesive is also a kind of surfactant, causing problems similar to the above-mentioned surfactant, antifoaming agents and various inorganic additives, etc. This causes a decrease.

A tackifier may be further added to improve the adhesive force of the aqueous emulsion adhesive, for example, rosin-based, terpene-based, xylene-based, petroleum-based, polybutene-based, and the like. Typically, the tackifier compatible with the acrylic latex in the pressure-sensitive adhesive improves the adhesive force up to 50 parts by weight relative to 100 parts by weight of the acrylic latex, but when used more than 50 parts by weight rather reduces the adhesive force.

The tackifier to which the tackifier having a softening temperature (Ts) higher than the glass transition temperature (Tg) of the acrylic latex is added tends to increase the glass transition temperature (Tg), and in general, the tackifier has a lower molecular weight than the acrylic latex. Cohesion tends to fall. For reference, J. Adhesion 82: 217-238,2006 describes the glass transition temperature (Tg) and the elastic change of the pressure-sensitive adhesive with the addition of a tackifier.

The tackifier can be divided into a fat soluble tackifier (or a water dispersible tackifier) and a water soluble tackifier. Since the fat soluble tackifier is easily dissolved in an organic solvent, dispersion is not a problem when added to the oil tackifier. Do not. Therefore, in the case of the oil-based adhesive, if the tackifier is compatible with the acrylic latex, the adhesive force can be easily adjusted by the amount of the tackifier added. For reference, J. Adhesion, 1995, Vol49, pp113-132 show the correlation between the compatibility of tackifier and the initial adhesion.

The water-soluble tackifier does not have a problem in dispersion when applied to the aqueous emulsion pressure-sensitive adhesive, but disadvantages than the fat-soluble tackifier in terms of price and has a disadvantage that is vulnerable to moisture. For reference, US 6,518,342 B1 discloses an example of preparing an aqueous emulsion adhesive using a rosin-based tackifier dissolved in an aqueous alkali solution, but has a problem of low economical efficiency and vulnerability to moisture.

When adding a fat-soluble tackifier to the aqueous emulsion pressure-sensitive adhesive, a method that can effectively raise while maintaining the dispersion stability to the desired content, there is a method of post-tacking the tackifier, but a process for the dispersion of the tackifier is required separately In addition, since a large amount of surfactant must be used for dispersion stability of the tackifier, a problem of deterioration of adhesion force due to the surfactant occurs.

An organic solvent may be used for effective dispersion stability of the tackifier, but it is not preferable because it is in conflict with advantages as an aqueous emulsion pressure-sensitive adhesive for reducing volatile organic compounds (T-VOC) harmful to humans. For reference, US 5,623,011 is an example of the post-treatment of a fat-soluble tackifier, using a fat-soluble tackifier from 8 to 15 parts by weight relative to 100 parts by weight of the adhesive resin, US 2007/0167546 A1 is a fat-soluble adhesive containing toluene As an example of preparing an imparting agent and mixing it with an adhesive resin, ammonium salt hydrogenated rosin and a protective colloid were applied as an emulsifier for the stability of the water-dispersible tackifier, and Korean Patent Laid-Open No. 2006-0005936 discloses a rosin-based tackifier resin with an acrylic oligomer. After mixing, the present invention relates to a method of preparing a tackifier by dispersing it in water with high shear force, and mixing it with an aqueous adhesive resin. In addition, Korean Patent Laid-Open Publication No. 10-2006-0102197 relates to a method for producing an aqueous emulsion pressure sensitive adhesive for PVC tiles, and it is described to prepare an aqueous emulsion pressure sensitive adhesive by adding a 1: 1 mixture of toluene and rosin to an acrylic latex. .

The method of polymerizing acrylic latex by including the tackifier in an acrylate monomer has also been disclosed in the related art, but since the tackifier is leached during the reaction, it is difficult to prepare a tackifier containing a high content of a tackifier. For reference, US 6,288,148 B1 is a method of emulsion polymerization by dissolving a xylene tackifier in an acrylate monomer and containing up to 6 parts by weight of a xylene tackifier relative to 100 parts by weight of an acrylic latex. -0073805 discloses an aqueous emulsion pressure sensitive adhesive for olefins having low polarity and thus poor adhesion, but rosin-modified maleic acid and rosin-modified glycerol esters are used as tackifiers.

In order to solve the problems of the prior art as described above, an object of the present invention is to provide an aqueous acrylic emulsion pressure-sensitive adhesive and a method for producing the same while retaining the adhesive strength and storage stability of the oil-based adhesive agent.

These and other objects of the present invention can be achieved by the present invention described below.

In order to achieve the above object, the present invention is an aqueous acrylic emulsion pressure-sensitive adhesive, i) alkyl acrylate, alkyl methacrylate or a mixture of 60 to 90% by weight thereof, ii) allyl ester, vinyl ester, unsaturated acetate or these 5 to 30% by weight of the mixture of (iii) unsaturated carbonic acid, 0.5 to 5% by weight of hydroxyl group-containing unsaturated monomer or mixtures thereof, i) 0.1 to 3% by weight of epoxy group-containing unsaturated monomer and (iii) 0.1 to 3% by weight of crosslinking agent. 100 parts by weight of the monomer mixture; And iii) 5 to 30 parts by weight of a tackifier; providing an aqueous acrylic emulsion pressure-sensitive adhesive having excellent adhesive strength and storage stability, and a method for producing the same, comprising an acrylic emulsion prepared by a polymerization reaction of an emulsion.

As described above, according to the present invention, the leaching of the tackifier is minimized during the emulsion polymerization while containing a tackifier of a predetermined amount or more, and does not cause the sick house syndrome while having the adhesiveness and storage stability of the oil-based adhesive level. / There is an effect to provide an aqueous acrylic emulsion pressure-sensitive adhesive and its manufacturing method that can be applied to exterior materials, interior materials, advertising films and other films that require adhesion.

Hereinafter, the present invention will be described in detail.

The aqueous acrylic emulsion pressure sensitive adhesive having excellent adhesive strength and storage stability of the present invention is, in the aqueous acrylic emulsion pressure sensitive adhesive, i) alkyl acrylate, alkyl methacrylate or a mixture thereof 60 to 90% by weight, ii) allyl ester, vinyl ester, unsaturated 5-30% by weight of acetate or mixtures thereof, i) 0.5 to 5% by weight of unsaturated carboxylic acid, hydroxyl-containing unsaturated monomer or mixtures thereof, i) 0.1 to 3% by weight of epoxy group-containing unsaturated monomer and i) 0.1 to 3% by weight of crosslinking agent. 100 parts by weight of the monomer mixture; And iii) 5 to 30 parts by weight of a tackifier; characterized in that it comprises an acrylic emulsion prepared by the polymerization of the emulsion containing.

The alkyl acrylate (monomer) is an acrylate compound substituted with an alkyl group having 1 or more carbon atoms, specifically, methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, butyl acrylate, isobutyl acrylate, heptyl acryl Latex, isooctylacrylate, 2-ethylhexyl acrylate, isodecyl acrylate and the like.

The alkyl methacrylate (monomer) is a methacrylate compound substituted with an alkyl group having 1 or more carbon atoms, specifically, methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, butyl methacrylate, t-butyl methacrylate, pentyl methacrylate, hexyl methacrylate, 2-ethylhexyl acrylate, octyl methacrylate, decyl methacrylate, dodecyl methacrylate, isobornyl methacrylate and the like.

The alkyl acrylate, alkyl methacrylate or a mixture thereof may be one or more, but is preferably a mixture of 3 to 7, more preferably 40 to 80% by weight of butyl acrylate, 2-ethylhexyl acrylate 5 To 30% by weight and methyl methacrylate 5 to 30% by weight.

The allyl ester, vinyl ester, unsaturated acetate or a mixture thereof is added to reinforce the adhesive strength of the pressure-sensitive adhesive, and more specifically, vinyl acetate, vinyl butylate, and the like, preferably vinyl acetate, and the content thereof is in the monomer mixture. It is preferably included in 5 to 30% by weight, more preferably in the range of 7 to 20% by weight.

The unsaturated carbonic acid, the hydroxyl group-containing unsaturated monomer or a mixture thereof is added to reinforce the adhesive strength of the pressure-sensitive adhesive, the unsaturated carbonic acid, for example, acrylic acid, itaconic acid, maleic acid, fumaric acid, methacrylic acid, ethyl meta The acrylic acid-containing unsaturated monomer may be hydroxymethyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxy propyl acrylate, 2-hydroxyethyl methacrylate, 2- Hydroxypropyl methacrylate and the like, preferably acrylic acid or methacrylic acid.

Specific examples of the epoxy group-containing unsaturated monomers include glycidyl (meth) acrylate, alphamethylglycidyl (meth) acrylate, glycidyl allyl ether, oxocyclohexyl (meth) acrylate, and 3,4-epoxy. Cyclohexylmethyl (meth) acrylate, and the like, preferably glycidyl methacrylate may be used, and the content thereof may be included in the monomer mixture in an amount of 0.1 to 3% by weight, preferably 0.3 to 1% by weight. It is to be included.

The crosslinking agent is added to reinforce cohesive force (gel content control) that is weakened by the low molecular weight tackifier, and is an organic crosslinking agent such as polyethylene glycol diacrylate, polypropylene glycol diacrylate, and 1,6-hexane. Diol diacrylate, trimethylol propane triacrylate, ethoxylated trimethyl propane triacrylate, tripropylene glycol diacrylate, 1,3-butanediol diacrylate, pentatrithitol triacrylate, 3-trimethoxy It may be one or more selected from the group consisting of silylpropyl methacrylate, vinyltrimethoxysilane, divinylbenzene and the like, and an inorganic crosslinking agent such as aluminum acetylacetonate, zinc acetate, zirconium carbonate, and the like, and preferably 1,6- Hexanediol diacrylate, polyethylene glycol diacrylate or It contains one or more of these.

The monomer mixture of i) to i) is polymerized into an acrylic resin (the reaction solution including the acrylic emulsion) by emulsion polymerization reaction. In order for the acrylic resin to realize significant heat resistance and adhesion, an appropriate glass transition temperature (Tg) Is required, and an appropriate gel content is required to achieve significant cohesion.

The glass transition temperature (Tg) of the acrylic resin may be -60 to 0 ℃, preferably -50 to -10 ℃, more preferably -40 to -20 ℃, when the temperature is -60 ℃ or less When it peels and peels off the tape apply | coated the adhesive adhered to the surface of an adhesive, an acrylic resin residue remains on the surface of an adhesive and contaminates an adhesive, and adhesive force becomes bad when it is 0 degreeC or more.

The gel content of the acrylic resin can be controlled by the crosslinking agent, preferably 30 to 90% by weight, more preferably 50 to 70% by weight. When the gel content is less than 30% by weight, the heat resistance is lowered and an acrylic resin residue remains on the surface of the adherend when peeling off the tape coated with the adhesive attached to the surface of the adherend, and contaminates the adherend. Adhesion is weakened due to poor adhesion to.

The tackifier is added to increase the adhesive strength of the acrylic resin (or acrylic emulsion containing acrylic resin), selected from the group consisting of rosin-based, terpene-based, petroleum-based, xylene-based, coumarone-based and polybutene It may be one or more, preferably using 5 to 30 parts by weight based on 100 parts by weight of the monomer mixture, preferably using an aromatic C9 or tepen tackifier of petroleum-based, more preferably 10 To 20 parts by weight.

The rosin-based tackifier may be rosin, hydrogenated rosin, hydrogenated rosin ester, and the like, and the terpene-based tackifier may be alphapinene resin, betapinene resin, dipentene, terpene-phenol resin, or the like, and petroleum-based adhesive agent. The imparting agent may be an aromatic C9-based tackifier or an aliphatic C5-based tackifier, wherein the aromatic C9-based tackifier is a copolymer of indene, styrene, methylindene, alphamethylstyrene, and the aliphatic C5-based tackifier Copolymers such as isoprene, cyclopentadiene, 1,3-pentadiene, 1-pentadiene, 2-pentene, dicyclopentadiene, and 1,3-pentadiene.

The emulsion is prepared by mixing the monomer mixture, the tackifier, water, surfactant, and the like.

The surfactant is used for the initial particle generation during the polymerization reaction, the size control of the generated particles and the stability of the particles, and is composed of a hydrophilic group and a lipophilic group, and is divided into anionic, cationic and nonionic surfactants. In general, anionic and nonionic surfactants are used a lot, and they may be mixed with each other to compensate for mechanical stability and chemical stability.

The anionic surfactant may be, for example, sodium alkyldiphenyl oxide disulfonate, sodium polyoxyethylene alkyl ether sulfate, sodium dialkyl sulfosuccinate, or the like. The nonionic surfactant may be, for example, polyethylene oxide alkyl. It may be an aryl ether, polyethylene oxide alkylamine, polyethylene oxide alkyl ester, and the like, these may be used alone or in combination of two or more, and may be more effective when used by mixing an anionic surfactant and a nonionic surfactant.

The surfactant is preferably used in an amount of 0.1 to 10 parts by weight based on 100 parts by weight of the monomer mixture, and more preferably used in an amount of 0.3 to 3 parts by weight. If it is less than 0.1 parts by weight, the stability of the water-based adhesive resin is lowered and 10 parts by weight. If it exceeds the amount, the adhesive strength is lowered.

The polymerization reaction is not particularly limited in the case of a conventional emulsion polymerization method, but in order to facilitate the control of the reaction heat, a monomer addition method (method of adding a monomer in a preemulsion process or an aging process) or seed. (Seed) polymerization method can be used.

The polymerization initiator is preferably a water-soluble initiator, and specific examples thereof include persulfates of ammonium or alkali metals, hydrogen peroxide, peroxides, hydroperoxides, and the like. Can also be used together.

The reducing agent may be sodium bisulfite, sodium metabisulfite, sodium hydrosulfite, sodium ciosulfate, sodium formaldehyde sulfoxylate, ascorbic acid, and the like.

It is preferable that the temperature of the said polymerization reaction is 0-100 degreeC, and when it considers the physical property of an adhesive, it is more preferable that it is 40-80 degreeC, The method of using the said initiator individually or in mixture of the said initiator and 1 or more types of said reducing agents. Can be adjusted.

The electrolyte used in the polymerization reaction is to adjust the pH and to impart stability to the acrylic resin (or latex) to be polymerized, specifically, from the group consisting of sodium bicarbonate, sodium carbonate, sodium phosphate, sodium sulfate and sodium chloride It may be one or more selected, preferably sodium carbonate, based on 100 parts by weight of the monomer mixture may be 0.1 to 2 parts by weight, preferably 0.3 to 1 parts by weight. For reference, the electrolyte may be included in the emulsion.

The acrylic emulsion may be applied to the pressure-sensitive adhesive without adjusting the pH (pH), preferably the acidity (pH) is adjusted to an alkaline material, and then may be applied to the pressure-sensitive adhesive.

The alkaline substance may be an inorganic substance such as hydroxide, chloride, carbonate of monovalent metal or divalent metal, ammonia or organic amine, or the like.

As for acidity (pH) of the said acrylic emulsion, 6-9 are preferable, More preferably, it is 7-8.

The aqueous acrylic emulsion pressure-sensitive adhesive may further include a thickener and a wetting agent (wetting agent) to prevent the shrinkage of the acrylic resin (or latex) generated when the pressure-sensitive adhesive is coated on the surface of the silicone release paper.

The thickener may be specifically CMC (Carboxyl Methyl Cellulose), acryl sol, polyvinyl alcohol, starch, alginate, dextrin and the like, preferably polyvinyl alcohol, 0.1 to 3 parts by weight based on 100 parts by weight of the monomer mixture Preferably, it is 0.1-1 weight part more preferably.

The wetting agent (wetting agent) is to change the hydrophilic adhesive to hydrophobic so that the adhesive adheres well to the surface of the hydrophobic silicone release paper, usually a surfactant mixture, glycol or alcohol may be further included.

The aqueous acrylic emulsion pressure-sensitive adhesive will generate bubbles in the process of mixing the post-treatment material (thickener, wetting agent, etc.), including the surfactant, these bubbles make the coating (coating) side of the pressure-sensitive adhesive, using an antifoaming agent Can be removed

The antifoaming agent is divided into a silicone-based, surfactant-based, paraffin-based, mineral oil type and the like, preferably silicon-based, the amount is preferably 0.05 to 0.5 parts by weight based on 100 parts by weight of the monomer mixture.

The method for preparing an aqueous acrylic emulsion pressure sensitive adhesive having excellent adhesive strength and storage stability of the present invention is a method for preparing an aqueous acrylic emulsion pressure sensitive adhesive, a) i) alkyl acrylate, alkyl methacrylate, or a mixture thereof 60 to 90% by weight, ii) 5 to 30% by weight of allyl ester, vinyl ester, unsaturated acetate or mixtures thereof, i) 0.5 to 5% by weight of unsaturated carboxylic acid, hydroxyl-containing monomer or mixtures thereof, i) 0.1 to 3% by weight of epoxy group-containing unsaturated monomer and i) 100 parts by weight of the monomer mixture consisting of 0.1 to 3% by weight of a crosslinking agent; And iii) 5 to 30 parts by weight of a tackifier; and b) preparing an acrylic emulsion by polymerizing the emulsion.

The details of the preparation of the emulsion of a) and the preparation of the acrylic emulsion of b) are the same as those described in the above-mentioned aqueous acrylic emulsion pressure-sensitive adhesive.

Hereinafter, preferred examples are provided to aid the understanding of the present invention, but the following examples are merely for exemplifying the present invention, and it will be apparent to those skilled in the art that various changes and modifications can be made within the scope and spirit of the present invention. It is natural that such variations and modifications fall within the scope of the appended claims.

[Example]

Example 1

<Production of Acrylic Emulsion>

Into a 2 L glass reactor equipped with a thermometer, stirrer, dropping funnel, nitrogen inlet tube and reflux condenser, 230 g of water, 0.1 g of sodium carbonate, and 10 g of 25% by weight aqueous solution of 25% by weight sodium alkyldiphenyloxide disulfonate as a surfactant were injected. It was. While stirring the glass reactor, the inside of the reactor was replaced with nitrogen, and then heated to 70 ° C. under a nitrogen atmosphere, and maintained for 30 minutes.

Separately, 400 g of butyl acrylate, 175 g of 2-ethylhexyl acrylate, 100 g of methyl methacrylate, 20 g of acrylic acid, 2 g of glycidyl methacrylate and 3 g of polypropylene diacrylate as a crosslinking agent were mixed. 70 g of a terpene system having a softening temperature (Ts) of 140 ° C. was added to the mixture as a tackifier, stirred for 30 minutes or more, and dissolved therein, and then 16 g of a 25 wt% aqueous sodium alkyldiphenyl oxide disulfonate solution as a surfactant was used. A solution consisting of 2 g of sodium carbonate and 340 g of water was added and mixed to prepare an emulsion.

0.4 g of ammonium persulfate was further added to the glass reactor and stirred for 10 minutes to dissolve it.

50 g of the emulsion and 50 g of 3 wt% ammonium persulfate aqueous solution were added dropwise to the glass reactor for 4 hours, and then 10 g of 3 wt% ammonium persulfate aqueous solution was further added thereto, and the temperature was raised to 80 ° C. for 30 minutes and 1 hour. This temperature was maintained, and then cooled to room temperature to prepare an acrylic emulsion.

The pH was adjusted to 7.5 by adding 30 wt% aqueous ammonia solution to the acrylic emulsion.

<Aqueous Acrylic Emulsion Adhesive and Adhesive Tape Specimen Preparation>

To 100 g of the acrylic emulsion (pH = 7.5), 1 g of polyvinyl alcohol as a thickener, 0.1 g of a silicone-based antifoaming agent, and 1 g of a wetting agent were added and stirred for 2 hours to prepare an aqueous acrylic emulsion pressure-sensitive adhesive.

The aqueous acrylic emulsion pressure-sensitive adhesive was applied to a silicone release paper sheet, and dried in an oven at 100 ° C. for 5 minutes to prepare a 55 μm thick adhesive sheet.

The adhesive sheet was laminated with a PVC sheet to obtain an adhesive tape, and the adhesive sheet was cut to a size of 25 mm * 100 mm to prepare an adhesive tape specimen.

Example 2

The same process as in Example 1 was performed except that the petroleum aromatic C9 copolymer obtained by copolymerizing an unsaturated aromatic olefin and a diolefin was used as a tackifier in Example 1.

Example 3

Except for using an alkylphenol modified xylene having a Ts of 100 ℃ as a tackifier in Example 1 was carried out in the same manner as in Example 1.

Example 4

Except for using the rosin-based Foral-85 of Eeastman as a tackifier in Example 1 was carried out in the same manner as in Example 1.

Example 5

Except for using the petroleum-based aliphatic C5 copolymerized aliphatic olefin and diolefin as a tackifier in Example 1 was carried out in the same manner as in Example 1.

Example 6

Except for using an alkylphenol modified xylene having a Ts of 70 ℃ as a tackifier in Example 1 was carried out in the same manner as in Example 1.

Example 7

Except for using 35g (5 parts by weight) of rosin-based Foral-85 of Eeastman as a tackifier in Example 1 was carried out in the same manner as in Example 1.

Comparative Example 1

Except that the tackifier was not added in Example 1 was carried out in the same manner as in Example 1.

[Test Example]

The properties of the acrylic emulsion, the aqueous acrylic emulsion pressure sensitive adhesive and the adhesive tape prepared in Examples 1 to 7 and Comparative Example 1 were measured by the following method, and the results are shown in Tables 1 and 2 below.

Viscosity Test: The viscosity of the aqueous emulsion pressure sensitive adhesive was measured using Brookfield Dv-III Ultra. Measurement conditions were 25 ℃, 12rpm, spindle No. LV3 was set.

* Adhesive force test: The adhesive force of the adhesive tape specimen was measured by peeling 5 times at a speed of 300 mm / min with a 2 kg roll in accordance with JIS Z 0237, waiting for 30 minutes, and peeling 180 degrees at a speed of 5 mm / sec using a TA Texture Analyzer. .

* Measurement of coagulum: The aqueous emulsion pressure-sensitive adhesive was filtered through a 200mesh fabric filter, and the filtered precipitate was dried in a 70 ° C. oven for 10 hours and weighed.

* Gel content measurement: 3g of an aqueous emulsion adhesive was dried in an oven at 70 ° C. for 12 hours to obtain an adhesive resin, which was placed in 100g of ethyl acetate, and left for 24 hours, which was then filtered through a 200mesh fabric filter and filtered. The gel content was calculated by weighing.

* Particle size measurement: The particle size was measured using a Nicomp 380 particle size analyzer applying the principle of light scattering by the particles.

* Conversion rate: The conversion rate was calculated using the theoretical solid content and the measured solid content.

division Tackifier Gel content (%) Particle size (nm) Kinds Content (parts by weight) Example 1 Terpene Ts 140 ℃ 10 64.8 179 Example 2 Petroleum C9 10 63.5 173 Example 3 Xylene Ts 100 ℃ 10 65.4 180 Example 4 Rosin Foral-85 10 63.2 177 Example 5 Petroleum C5 10 64.4 184 Example 6 Xylene Ts 70 ℃ 10 66.1 187 Example 7 Rosin Foral-85 5 68.7 176 Comparative Example 1 - - 74.4 175

division Adhesion (kgf / in) Coagulum (%) Viscosity (cps) % Conversion Example 1 3.0 0.23 350 98.0 Example 2 2.8 0.32 290 97.4 Example 3 2.3 0.25 360 98.1 Example 4 2.5 0.21 300 97.1 Example 5 2.3 0.30 310 97.5 Example 6 2.2 0.26 360 97.3 Example 7 2.0 0.11 120 98.5 Comparative Example 1 1.7 0.02 40 99.6

As shown in Table 1, the aqueous acrylic emulsion pressure-sensitive adhesive (Examples 1 to 7) of the present invention was confirmed that the adhesive strength is superior to the aqueous acrylic emulsion pressure-sensitive adhesive (Comparative Example 1) does not contain a tackifier, a coagulum Was measured at less than 0.5% by weight, the viscosity was all less than 500 cps did not cause problems in the reaction process (mixing) due to the high viscosity, the conversion rate tended to decrease as the content of the tackifier increases.

For reference, the tackifier was excellent in the order of terpene-based, petroleum-based aromatic C9, rosin-based, xylene-based, in the case of higher softening temperature (Ts) or higher content of the tackifier was confirmed .

Claims (13)

In an aqueous acrylic emulsion adhesive, Iii) 60 to 90% by weight of alkyl acrylate, alkyl methacrylate or mixtures thereof, ii) 5 to 30% by weight of allyl esters, vinyl esters, unsaturated acetates or mixtures thereof, iii) unsaturated carboxylic acids, hydroxyl-containing unsaturated monomers Or 0.5 to 5% by weight of these mixtures, i) 100 parts by weight of a monomer mixture consisting of 0.1 to 3% by weight of an epoxy group-containing unsaturated monomer and v) 0.1 to 3% by weight of a crosslinking agent; And iii) 5 to 30 parts by weight of a tackifier; comprising an acrylic emulsion prepared by polymerization reaction. An aqueous acrylic emulsion pressure sensitive adhesive having excellent adhesive strength and storage stability. The method of claim 1, The alkyl acrylate, alkyl methacrylate or a mixture thereof is 40 to 80% by weight of butyl acrylate, 5 to 30% by weight of 2-ethylhexyl acrylate and 5 to 30% by weight of methyl methacrylate, characterized in that An aqueous acrylic emulsion pressure sensitive adhesive having excellent adhesive strength and storage stability. The method of claim 1, The allyl ester, vinyl ester, unsaturated acetate or a mixture thereof is characterized in that the vinyl acetate An aqueous acrylic emulsion pressure sensitive adhesive having excellent adhesive strength and storage stability. The method of claim 1, The unsaturated carbonic acid, hydroxyl group-containing unsaturated monomer or a mixture thereof is acrylic acid, methacrylic acid or a mixture thereof. An aqueous acrylic emulsion pressure sensitive adhesive having excellent adhesive strength and storage stability. The method of claim 1, The epoxy group-containing unsaturated monomer is glycidyl methacrylate, characterized in that An aqueous acrylic emulsion pressure sensitive adhesive having excellent adhesive strength and storage stability. The method of claim 1, The crosslinking agent is 1,6-hexanediol diacrylate, polyethylene glycol diacrylate or characterized by containing at least one of them An aqueous acrylic emulsion pressure sensitive adhesive having excellent adhesive strength and storage stability. The method of claim 1, The acrylic resin is characterized in that the glass transition temperature (Tg) is -60 to 0 ℃. An aqueous acrylic emulsion pressure sensitive adhesive having excellent adhesive strength and storage stability. The method of claim 1, The acrylic resin is characterized in that the gel content of 30 to 90% by weight. An aqueous acrylic emulsion pressure sensitive adhesive having excellent adhesive strength and storage stability. The method of claim 1, The tackifier is at least one member selected from the group consisting of rosin-based, terpene-based, petroleum-based, xylene-based, coumarone-based and polybutene An aqueous acrylic emulsion pressure sensitive adhesive having excellent adhesive strength and storage stability. The method of claim 1, The tackifier is petroleum-based aromatic C9 system, terpene system or a mixture thereof An aqueous acrylic emulsion pressure sensitive adhesive having excellent adhesive strength and storage stability. The method of claim 1, The acrylic emulsion is characterized in that it is adjusted to acidity (pH) 6 to 9 including an alkaline substance. An aqueous acrylic emulsion pressure sensitive adhesive having excellent adhesive strength and storage stability. The method of claim 1, The aqueous acrylic emulsion pressure-sensitive adhesive further comprises one or more selected from the group consisting of thickeners, wetting agents and antifoaming agents. An aqueous acrylic emulsion pressure sensitive adhesive having excellent adhesive strength and storage stability. In the manufacturing method of an aqueous acrylic emulsion adhesive, a) i) 60 to 90% by weight of alkyl acrylate, alkyl methacrylate or mixtures thereof, ii) 5 to 30% by weight of allyl esters, vinyl esters, unsaturated acetates or mixtures thereof, i) containing unsaturated carboxylic acids, hydroxyl groups 100 parts by weight of a monomer mixture consisting of 0.5 to 5% by weight of an unsaturated monomer or a mixture thereof, i) 0.1 to 3% by weight of an epoxy group-containing unsaturated monomer and v) 0.1 to 3% by weight of a crosslinking agent; And iii) 5 to 30 parts by weight of a tackifier; preparing an emulsion comprising; And b) polymerizing the emulsion to prepare an acrylic emulsion; Characterized in that it comprises A method for producing an aqueous acrylic emulsion pressure sensitive adhesive having excellent adhesive strength and storage stability.