KR101350515B1 - Acrylic sticky adhesive composition of water dispersion - Google Patents

Abstract

상기 식1에서 m과 n은 각각 10 내지 30의 정수 이고 X는 음이온성, 양이온성, 비이온성 또는 양쪽 이온성 친수기이고, 바람직하게는 H 또는 SO₃NH₄ 이고, R₁은 알케닐, 바람직하게는 알릴 또는 에텐일기이고 R₂는 알킬기, 바람직하게는, 메틸, 에틸 또는 프로필기 이다.
본 발명에 의하여 노닐 또는 페닐 계 유화제를 사용하지 않고도 초기 접착력과 유지력이 양호하면서도 내수성과 내후성이 좋은 수분산형 아크릴계 점착제 조성물이 제공된다.The present invention relates to a water-dispersible acrylic pressure-sensitive adhesive composition, 80 to 95 parts by weight of unsaturated carboxylic acid ester having a glass transition temperature of -130 ~ -25 ℃; 5 to 20 parts by weight of unsaturated carboxylic acid ester having a glass transition temperature of -25 to 130 ° C; 0.1-5 parts by weight of a polyoxyalkylene alkenyl ether represented by the following Formula 1; and an aqueous dispersion-type acrylic pressure-sensitive adhesive composition formed by emulsion polymerization of a polymerizable material comprising 0.05 to 2 parts by weight of an initiator.
Equation 1

Wherein m and n are each an integer of 10 to 30, X is an anionic, cationic, nonionic or zwitterionic hydrophilic group, preferably H or SO ₃ NH ₄ , and R ₁ is alkenyl, preferably Preferably an allyl or ethynyl group and R ₂ is an alkyl group, preferably methyl, ethyl or propyl group.
The present invention provides a water-dispersible acrylic pressure-sensitive adhesive composition having good initial adhesive force and good holding power and good water resistance and weatherability without using a nonyl or phenyl emulsifier.

Description

Acrylic sticky adhesive composition of water dispersion

The present invention relates to an acrylic pressure-sensitive adhesive composition, in particular an acrylic pressure-sensitive adhesive composition having good adhesive properties on both non-polar and polar materials without a decrease in weather resistance due to emulsifier migration. The scope of use of adhesives is not only increasing, but also playing an important role in the industry as the relevant market is growing. In general, the pressure sensitive adhesive is a high molecular material having a low glass transition temperature (Tg). The water-dispersible pressure-sensitive adhesive composition composed mainly of the acrylic polymer having such a low glass transition temperature is used for labels, medical and decorative tapes, flooring materials, automotive interior materials and the like.

Various patents and papers have been introduced on Ulrich's patents on acrylic adhesives using acrylic acid, methacrylate or itaconic acid and amide substituents thereof, as well as various applications of co-monomers.

Organic solvent-type acrylic adhesives are relatively excellent in performance such as adhesion and heat resistance, but use of organic solvents harmful to human body increases the need for products with less pollution due to the demand for cleanliness for the working environment or the use environment.

Korean Patent No. 0165527 discloses an acrylic adhesive having water dispersible heat resistance instead of an organic solvent type. The patent discloses an acrylic adhesive prepared by emulsion polymerization by heating acrylates, carboxylic acrylics, acrylics having epoxy groups, acrylamides and acrylonitriles in batches in a water phase form. However, acrylic emulsion adhesives have a problem of environmental pollution due to nonyl and phenyl emulsifiers which are generally used, and a problem of reducing weather resistance due to emulsification agent emulsion.

Sufficiently low glass transition temperatures are required for the synthesized copolymer to achieve low elastic modulus and adequate initial tack. The low glass transition temperature of the monomer gives higher plasticity than the polymerization of the main monomer alone. On the contrary, the higher the glass transition temperature of the copolymer, the higher the stiffness of the adhesive. It is advantageous for imparting initial adhesion. However, the physical properties of the final polymer may be deteriorated depending on the content and chemical properties of the second and third co-monomers used, so care must be taken in selecting them.

In addition, acrylic carboxylic acid is used for the purpose of improving the initial adhesive force, which is rich in polarity, which causes a problem of deterioration in adhesive strength to nonpolar materials.

There is also a technique of introducing a tackifier as a method of increasing the initial adhesive strength and adhesion to nonpolar materials, which are largely divided into rosin, terpene, and hydrocarbon. The tackifier has the advantage of easily increasing the initial adhesive strength by physical mixing, but must be compatible with the polymer, have a higher glass transition temperature and a lower molecular weight than the polymer, and have discoloration. There is also a drawback that you have to pay attention to use as it may happen.

The present invention is to provide a water-dispersible acrylic pressure-sensitive adhesive composition having good adhesion properties to both non-polar materials and polar materials.

In addition, the present invention is to provide a water-dispersible acrylic pressure-sensitive adhesive composition having excellent initial adhesive strength without deterioration of physical properties or weather resistance accompanied by the mixing of the tackifier and emulsifier.

In addition, the present invention is to provide a water-dispersible acrylic pressure-sensitive adhesive composition that does not use a nonylphenyl-based emulsifier is environmentally excellent and there is no degradation of physical properties by emulsifier migration.

According to the present invention, the glass transition temperature is -130 ~ -25 ℃ 80 to 95 parts by weight of unsaturated carboxylic acid ester; 5 to 20 parts by weight of unsaturated carboxylic acid ester having a glass transition temperature of -25 to 130 ° C; Provided is a water-dispersible acrylic pressure-sensitive adhesive composition formed by emulsifying and polymerizing a polymerizable material comprising 0.1 to 5 parts by weight of a polyoxyalkylene alkenyl ether represented by the following Formula 1; and 0.05 to 2 parts by weight of an initiator. In the present invention, the polymerizable material may preferably further include 0.1 to 7 parts by weight of β-carboxyethyl acrylate represented by the following Formula 2, and 0.5 to 5 parts by weight. In addition, the polymerizable material in the present invention, preferably, may further comprise 1 to 20 parts by weight of a hydrocarbon C5-based tackifier modified with a rosin-based or hydrocarbon C5-based or acrylic monomer. If necessary, the polymerizable material may further include 0.1 to 3 parts by weight of unsaturated carboxylic acid. If necessary, the polymerizable material may further include 3 parts by weight or less of an ionic or nonionic surfactant. In addition, if necessary, the polymerizable material may further include 0.1 to 1 parts by weight of a PH regulator.

Equation 1

Wherein m and n are each an integer of 10 to 30, X is an anionic, cationic, nonionic or zwitterionic hydrophilic group, preferably H or SO ₃ NH ₄ and R ₁ is an alkenyl group, preferably Is an alkenyl group of C2 to C5, most preferably an allyl or ethenyl group and R ₂ is an alkyl group, preferably an alkyl group of C1 to C5, most preferably a methyl, ethyl or propyl group.

Equation 2

In Equation 2, n is 0, 1, 2 ... and the average value is approximately 1.

When the unsaturated carboxylic acid ester having a glass transition temperature of -130 to -25 ° C is less than 80 parts by weight as an adhesive monomer, the tackiness decreases, so that the physical properties of the adhesive are weak. As a result, the adhesive area becomes wider and the re-peelability decreases. Unsaturated carboxylic acid ester as an adhesive monomer is propyl acrylate, butyl acrylate, 2-ethylbutyl acrylate, hexyl acrylate, heptyl acrylate, octyl acrylate, n-pentyl acrylate, 2-ethylhexyl acryl, for example. Rate and the like.

The unsaturated carboxylic acid ester having a glass transition temperature of -25 to 130 ° C. has a low cohesion when the cohesive monomer is less than 5 parts by weight. Degrades. As said coherent monomer, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl methacrylate, isobutyl acrylate, isobutyl methacrylate, hexyl methacrylate, pentyl Methacrylate, oxyl methacrylate, and the like.

The polyoxyalkylene alkenyl ether represented by Formula 1 above is introduced as part of an acrylic copolymer and is an emulsifier of an acrylic copolymer that is emulsified and polymerized with monomers by anionic, cationic or nonionic hydrophilic part and lipophilic part of the ether chain. It acts and does not cause the migration of emulsifiers, thereby increasing the storage safety of emulsion polymerized acrylics. Wherein n is an integer of 10 to 30 and X is an anionic, cationic, nonionic or zwitterionic hydrophilic group. Anionic hydrophilic groups include, for example, sulfuric acid, sulfonic acid or organic phosphoric acid, and cationic, for example, ammonium and nonionic, for example, H or SO ₃ NH _4. .

When the polyoxyalkylene alkenyl ether is used in an amount of less than 0.1 part by weight based on 100 parts by weight of the mixed monomer, dispersion of the monomer or polymer tends to be unstable, and when used in excess of 5 parts by weight, it tends to reduce water resistance and weather resistance. . Therefore, the usage-amount is 0.1 weight part-5 weight part, Preferably it is 1-3 weight part.

The β-carboxyethyl acrylate is a mixture of adducts where n is 0, 1, 2, 3 ... in Equation 2, where n is most often 1 and the average value is approximately 1. In particular, the present invention is used in an amount of 0.1 to 7 parts by weight to be used to improve the initial adhesion and the adhesion to nonpolar materials, and less than 0.1 parts by weight of the adhesion improving effect, in particular, the adhesion to the nonpolar material is less than 7 parts by weight Tends to harden.

In order to increase the initial adhesion of the pressure-sensitive adhesive composition, the polymerizable material may further contain unsaturated carboxylic acid, preferably acrylic acid in an amount of 0.1 to 3 parts by weight.

The initiator is not particularly limited as a radical thermal initiator, but inorganic salt initiators such as ammonium persulfate and potassium persulfate are preferably used. The amount of the initiator is used in an amount of 0.1 to 2 parts by weight, preferably 0.5 to 1 part by weight based on approximately 100 parts by weight of the mixed monomer.

 The polymerizable material may further include 1 to 10 parts by weight of a hydrocarbon C5 tackifier modified with a rosin-based or hydrocarbon C5-based or acrylic monomer to improve initial adhesion and adhesion to a non-polar material. Such a tackifying component may be mixed with the monomer component to participate in copolymerization to achieve weather resistance or deformation resistance. Such tackifiers include rosin-based (100F, Wuzhou, SP; 100 ° C), C5-based (A-100, Nipon Zeon, SP; 100 ° C) or C5-based (PX-95 Kolon Oil, SP; 95 ° C.). Particularly preferred tackifiers in the present invention include dicyclopentadiene modified with an acrylic monomer represented by the following formula (3).

Equation 3

In the present invention, the emulsion polymerization is carried out by adding and mixing an initiator and a polymerizable substance consisting of an acrylic monomer, polyoxyalkylene alkenyl ether of formula 1 and a tackifier in a reactor filled with water and a pH adjusting agent. As the pH adjusting or buffering agent, for example, sodium sulfite, sodium sulfate, sodium carbonate and sodium bicarbonate are used as the inorganic base. When there is acidity in the pre-emulsion that is dropped during emulsion polymerization, the acidity of the lower reaction solution increases as the dropping amount increases, so that the reaction particles do not occur uniformly, so that the emulsion particles of the emulsion polymerization resin composition do not grow evenly. Therefore, it is preferable to use an appropriate amount of pH adjusting agent. The pH adjusting agent is used 0.1 parts to 1 parts by weight, preferably 0.2 to 0.5 parts by weight based on approximately 100 parts by weight of the mixed monomer.

The present invention provides a water-dispersible acrylic pressure-sensitive adhesive composition having good initial adhesive force and good holding power and good water resistance and weatherability without using a nonyl or phenyl emulsifier.

Hereinafter, the present invention will be described in more detail with reference to Examples. These examples are intended to illustrate the invention and should not be construed as limiting the protection scope of the invention. In the embodiment of the present invention, the component ratio is an acrylic monomer by weight unless otherwise specified, and the other component ratio is a weight part based on 100 parts by weight of the total acrylic monomer.

Example 1.

Beaker A 53 wt% 2-ethylhexyl acrylate (abbreviated as "2-EHA"), 35 wt% butyl acrylate (abbreviated as "BA"), 10 wt% methyl methacrylate ("MMA") Tackifier pentaerythritol ester gum rosin (Wuzhou Co., Ltd.) containing 1% by weight of acrylic acid (abbreviated as "AAc") and 1% by weight of methacrylic acid (abbreviated as "MAc") based on 100 parts by weight of the total monomers 100F) 10 parts by weight of the solution is mixed and dissolved.

Based on 100 parts by weight of the total monomers, polyoxyalkylene allyl ether ammonium sulfate of Formula 1 wherein R ₁ is allyl and R ₂ is ethyl And X is SO ₃ NH ₄ and m and n are each optionally referred to as "AF-10", each 10.) 1.5 parts by weight of a polyoxyethyleneoxypropylene ether of formula 1 wherein R _{1 is} a nonionic reactive emulsifier. Is allyl, R ₂ is ethyl, X is H, m and n are each optionally referred to as "NF-20" as 20.) 1.5 parts by weight are mixed and stirred for 10 minutes at a stirring speed of 300 rpm.

A beaker A solution was added dropwise to the beaker B solution for 30 minutes to prepare a monomer emulsion.

Based on 100 parts by weight of the total monomers, 0.3 parts by weight of a reaction initiator potassium persulfate (hereinafter referred to as "KPS") is dissolved in 8 parts by weight of ion-exchanged water in Beaker C.

Based on 100 parts by weight of all monomers, 42 parts by weight of ion-exchanged water and 0.2 parts by weight of sodium bicarbonate (used as a buffer) were placed in a flask D in a nitrogen gas atmosphere equipped with a reflux condenser, thermometer, stirrer, and a micropump at 100 rpm. The temperature is raised to 85 ° C while stirring.

The monomer emulsion of Beaker B and the solution of Beaker C prepared in advance are added dropwise to Flask D at a constant rate for 4 hours through a micropump. After completion of the dropwise addition, the mixture was subjected to aging for 1 hour and 30 minutes, and then cooled to terminate the reaction, thereby preparing a water-dispersible acrylic pressure-sensitive adhesive of the present invention. Each component ratio is put together in Table 1.

Property evaluation

The prepared acrylic pressure-sensitive adhesive was applied on a polyester film with a thickness of 40 m and then dried at 70 ° C. for 5 minutes. After releasing the release paper was aged for 8 hours at 40 ℃ to prepare a specimen. Peel strength evaluation, holding power evaluation, weather resistance evaluation and water resistance evaluation of the specimens are shown in Table 2 based on the following criteria.

 a. Peel Strength

The specimen coated with a 40 m dry thickness on the polyester film was allowed to stand on a polyethylene plate at room temperature for 1 hour, and then 180 ° peel strength was measured as follows.

-Size: 25 mm × 150 mm

-Peeling Speed: 300mm / min

  b. Holding Power Evaluation

A specimen coated with a dry thickness of 40 m on the polyester film was coalesced into a stainless plate with a predetermined area (25 mm x 25 mm) and pressed. After standing at room temperature for 1 hour, a load of 1 kg was applied at 40 ° C., and the peeled distance was measured for 1 hour to evaluate condition and heat creep resistance.

  c. Weatherability evaluation

The specimen coated with a 40 m dry thickness on the polyester film was pressed twice on a stainless plate with a 2 kg roller, left at 60 ° C. for 24 hours, then cooled to room temperature, and 180 ° peel strength was measured under the same conditions as the above evaluation of adhesive force. .

  d. Water resistance rating

The specimen coated with a 40 m dry thickness on the polyester film was left to stand at 60 ° C. for 8 hours to evaluate a state in which the pressure-sensitive adhesive film was transparent or changed to a cloudy appearance.

Each component ratio is put together in Table 1.

Examples 2 to 4

In Examples 2 to 4, unlike Example 1, 1 wt%, 2 wt%, and 3 wt% of β-carboxyethyl acrylate (abbreviated as "β-CEA") of Formula 1 were used as monomers. The amount of monomer was adjusted as shown in Table 1, and the tackifier was changed and the reactive emulsifier (AF-10, 20 or NF-10, 20 or 30 depending on the value of n in Equation 1) was performed. Each component ratio is put together in Table 1. In addition, the physical property evaluation is shown in Table 2.

Comparative Example 1

The amount of monomer was changed as shown in Table 1, and the emulsifier was carried out except that 1.5 parts by weight of a general emulsifier, polyoxyethylene nonylphenyl ether (NP-1050, Southeastern NP) and Sodium dodecylbenzene sulphonate (DS-4, Rhodia) were used. It carried out as Example 1. Each component ratio is put together in Table 1. In addition, the physical property evaluation is shown in Table 2.

division Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Monomer 2-EHA 53 53 53 50 60 BA 35 34 33 35 28 MMA 10 10 10 10 10 AAc One 2 One 2 One MAc One - One - One B-CEA - One 2 3 - Ion-exchange water 40 40 40 40 40 Initiator KPS 0.3 0.3 0.3 0.3 0.3 Ion-exchange water 8 8 8 8 8 Buffer Ion-exchange water 42 42 42 42 42 NAHCO3 0.2 0.2 0.2 0.2 0.2 Tackifier
100F 10 - 5 - 10 A-100 - 10 5 - - PX-95 - - - 10 - Polymerizable emulsifiers
NF-10 1.5 - 1.5 1.5 - NF-20 - 1.5 - - - AF-10 1.5 - 1.5 1.5 - AF-20 - 1.5 - - - General emulsifiers NP-1050 - - - - 1.5 DS-4 - - - - 1.5 Tg (占 폚) -50.4 -48.6 -50.8 -50.9 -51.8

division Adhesive force (kgf / 25mm) Holding force (mm) Weather resistance (kgf / 25mm) Water resistance Example 1 0.9 3 0.9 Transparency Example 2 One One One Transparency Example 3 1.1 0 1.2 Transparency Example 4 1.3 0 1.5 Transparency Comparative Example 1 0.5 8 0.4 Cloudiness

Claims (6)

delete 80 to 95 parts by weight of unsaturated carboxylic acid ester having a glass transition temperature of -130 to -25 ° C; 5 to 20 parts by weight of unsaturated carboxylic acid ester having a glass transition temperature of -25 to 130 ° C; 0.1 to 5 parts by weight of polyoxyalkylene alkenyl ether represented by the following Formula 1; 0.1 to 7 parts by weight of β-carboxyethyl acrylate represented by the following Formula 2; and a water-dispersible acrylic pressure-sensitive adhesive composition formed by emulsion polymerization of a polymerizable material comprising 0.05 to 2 parts by weight of an initiator.
Equation 1

In Formula 1, m and n are each an integer of 10 to 30, X is an anionic, cationic, nonionic or zwitterionic hydrophilic group, R ₁ is an alkenyl group, and R ₂ is an alkyl group.
Equation 2

In Equation 2, n is 0, 1, 2 ... and the average value is approximately 1. The water-dispersible acrylic pressure-sensitive adhesive composition of claim 2, wherein the polymerizable material further comprises 1 to 20 parts by weight of a hydrocarbon C5-based tackifier modified with a rosin-based or hydrocarbon C5-based or acrylic monomer. The water-dispersible acrylic pressure-sensitive adhesive composition of claim 2, wherein the polymerizable material further comprises 0.1 to 3 parts by weight of unsaturated carboxylic acid. The water dispersible acrylic pressure-sensitive adhesive composition of claim 3, wherein the tackifier is a material represented by the following Formula 3.
Equation 3

The water-dispersible acrylic pressure-sensitive adhesive composition of claim 2, wherein the polymerizable material further comprises 0.1 to 1 parts by weight of a PH regulator.