KR100560053B1 - Adhesive composition based vinyl acetate - Google Patents

Abstract

The present invention relates to a vinyl acetate-based adhesive composition, in particular, having a property and adhesion comparable to that of a conventional adhesive without using a plasticizer, including vinyl acetate monomer, vinyl acetate-ethylene emulsion, polyvinyl alcohol, and water. In addition to solving the problem of decreased adhesive strength during winter use, at the same time, environmentally friendly and human-friendly, and excellent adhesion, storage stability, heat resistance, water resistance, workability, in particular water-resistant adhesive film and low temperature film-forming film composition It is about.

Adhesives, vinyl acetate monomers, vinyl acetate-ethylene emulsions, low temperature film

Description

Vinyl acetate type adhesive composition {ADHESIVE COMPOSITION BASED VINYL ACETATE}

1 is a graph comparing the water resistance of the vinyl acetate-based adhesive prepared according to the present invention and the conventional vinyl acetate-based adhesive.

Figure 2 is a graph showing the storage stability (50 ℃) of the vinyl acetate-based adhesive prepared according to an embodiment of the present invention.

Figure 3 is a graph showing the storage stability (4 ℃) of the vinyl acetate-based adhesive prepared in accordance with an embodiment of the present invention.

The present invention relates to a vinyl acetate-based adhesive composition, more specifically, having a physical property and adhesive strength comparable to conventional adhesives without using a plasticizer, not only can solve the problem of reducing the adhesive strength during winter use, The present invention relates to a vinyl acetate-based adhesive composition which is environmentally friendly and human-friendly, and has excellent adhesion, storage stability, heat resistance, water resistance, workability, particularly water resistance and low temperature film forming properties.

In modern society, adhesives have a wide range of applications, and mainly vinyl acetate resin is used.

Vinyl acetate resin is not used as a molding material because the glass transition temperature is near room temperature. However, it is widely used as an adhesive, a paint, a resin processing agent, etc. due to its excellent adhesion. In particular, vinyl acetate used as an adhesive is widely used for woodworking and paper bonding.

However, the vinyl acetate resin alone has a high temperature dependence of viscosity, has a problem of viscosity increase and workability deteriorated at low temperatures in winter, and is used by adding a phthalate plasticizer to compensate for this. However, due to the use of the phthalate-based plasticizer, the adhesive strength is weakened and the heat resistance is lowered. In particular, there is a problem that the amount of the plasticizer should be increased in winter.

In addition, in high-concentration products, not only do they cause an increase in viscosity, worsen workability and delay curing, but phthalate plasticizers are regulated as environmental hormones.

Therefore, there is a need for further research on adhesives that can exhibit physical properties and adhesion comparable to those of conventional vinyl acetate resins without the use of phthalate-based plasticizers.

In order to solve the problems of the prior art as described above, the present invention solves the problem that the physical properties are lowered or the adhesive strength is reduced after a low temperature or a long time without the use of a plasticizer having a similar degree of physical properties and adhesion An object of the present invention is to provide a vinyl acetate-based adhesive composition having excellent adhesion, water resistance, and storage stability.

It is another object of the present invention to provide a vinyl acetate-based adhesive composition which is environmentally friendly and human-friendly and at the same time excellent in adhesive strength, storage stability, water resistance, heat resistance, workability, particularly water resistance and low temperature film forming properties.

In order to achieve the above object, the present invention is a vinyl acetate adhesive composition,

a) 10 to 50% by weight of vinyl acetate monomer;

b) 5 to 30% by weight of vinyl acetate-ethylene emulsion;

c) 1 to 30% by weight of polyvinyl alcohol; And

d) remaining water

It provides a vinyl acetate-based adhesive composition comprising a.

In another aspect, the present invention provides a method for producing a vinyl acetate-based adhesive composition comprising the step of emulsion-polymerizing polyvinyl alcohol in water and the reaction by adding a vinyl acetate monomer and a vinyl acetate-ethylene emulsion to the polymerization reaction.

Hereinafter, the present invention will be described in detail.

The inventors of the present invention studied an adhesive that can exhibit excellent physical properties and adhesion without using a phthalate-based plasticizer. As a result of polymerizing a vinyl acetate monomer and a vinyl acetate-ethylene emulsion in an adhesive, the present inventors have found that the adhesive and In addition to solving the problem that the adhesion strength is reduced by the addition of the phthalate plasticizer when the winter season, while having a similar degree of physical properties and adhesion, it is confirmed that the water-resistant adhesion and low-temperature film film formation is significantly improved, based on the present invention To complete.

Vinyl acetate-based adhesive composition of the present invention is characterized in that it comprises 10 to 50% by weight of vinyl acetate monomer, 5 to 30% by weight of vinyl acetate-ethylene emulsion, 1 to 30% by weight of polyvinyl alcohol, and the balance of water.

The vinyl acetate monomer (VAM) of a) used in the present invention is preferably included in the adhesive in an amount of 10 to 50% by weight, more preferably 20 to 35% by weight. When the content is in the above range, the adhesive composition can maintain the viscosity of the proper range, there is an excellent adhesive force.

The vinyl acetate monomer may be used alone in the adhesive composition, or may be used by copolymerizing with the monomer as necessary.

The copolymerizable monomer may be acrylic ester (ester acrylate), acrylic acid (CH ₂ = CHCOOH), ethylene, styrene, acrylate, or methacrylate, and particularly preferably acrylic ester or acrylic acid. Do. Specifically, the acrylate ester is a butyl acrylate monomer (butyl acrylate monomer), ethyl acrylate monomer (ethyl acrylate monomer), ethylhexyl acrylate monomer (ethylhexyl acrylate monomer), methyl acrylate monomer (methyl acrylate monomer) and the like Can be used.

The monomer is preferably included in 0.1 to 20 parts by weight with respect to 100 parts by weight of vinyl acetate monomer, when the content is in the above range has the effect of further improving the adhesive strength of the adhesive composition.

The vinyl acetate-ethylene emulsion (VAE) of b) used in the present invention is prepared by copolymerizing an ethylene monomer and a vinyl acetate monomer.

Of course, the ethylene monomer and the vinyl acetate monomer can be used in the conventional monomers used in the art, in particular, the copolymerization of the content of 10 to 20% by weight of ethylene monomer and 80 to 90% by weight of vinyl acetate monomer.

In the vinyl acetate-ethylene emulsion, it is preferable to use a relatively low glass transition temperature (Tg), and in particular, a low temperature film forming property (minimum flim forming) is preferable to use a glass transition temperature (Tg) of -10 to -20 ℃. temperature, MFT).

The vinyl acetate-ethylene emulsion is preferably included in the adhesive composition 5 to 30% by weight, more preferably 10 to 20% by weight. When the content is in the above range, it is possible to lower the glass transition temperature of the adhesive composition to improve the film film temperature characteristics at low temperatures.

The polyvinyl alcohol (polyvinyl alcohol, PVA) of the c) used in the present invention serves to adjust the viscosity of the adhesive.

The polyvinyl alcohol is a colorless transparent thermoplastic resin having a specific gravity of 1.19 (20 ° C.) and having good light resistance, and is not colored by heat and does not age. In addition, the absorbency is 23% (25 ℃, 24 hours), the tensile strength is about 330 kg · cm 2, cured at 60 ~ 70 ℃ and decomposes at 200 ℃.

Preferably, the polyvinyl alcohol has a polymerization degree of 1500 to 3000 and a saponification degree of 80 to 99%, and the content of the polyvinyl alcohol is preferably contained in an adhesive composition of 1 to 30% by weight, more preferably 3 to 10. It is included by weight. When the content is within the above range, not only the workability is excellent by maintaining the viscosity of the adhesive composition in an appropriate range, but also the effect of excellent adhesive strength and adhesion.

The water of d) used in the aqueous adhesive composition of the present invention is preferably contained in the remaining amount in the adhesive composition.

The water is used as a solvent in the adhesive composition, by using the water as a solvent to solve the problem of environmental damage caused by the use of the organic solvent not only environmentally friendly, but also during the construction or after construction of severe chemical smell By suppressing, the worker's work efficiency can be improved, and workability can be improved, and when the tenant moves into a constructed building, there is an advantage of living comfortably without feeling the unpleasant feeling of piercing the nose.

The vinyl acetate adhesive composition of the present invention comprising the above components is a functional filler, a dispersant, an antifoaming agent, a stabilizer, a leveling agent, a tackifier, or a catalyst used in a conventional vinyl acetate adhesive composition, if necessary, in addition to the above components. Additives such as may be further included in the adhesive composition at 0.001 to 3% by weight.

The vinyl acetate-based adhesive composition of the present invention is used for bonding wood, such as furniture, building materials, musical instruments, toys, assembling, decorating plates, melamine decorative boards, etc., in addition to bonding a soft vinyl sheet to plywood or paper, or sticking paper coated with vinyl. The application can be used by applying a brush or a roller to the surface to be adhered, and then immediately attaching it within 30 minutes after application. It is preferable that the said coating amount is at least 50-200 g / m <2>.

In addition, the present invention is the step of emulsion polymerization of 1 to 30% by weight of polyvinyl alcohol in 20 to 80% by weight of water and 10 to 50% by weight of the vinyl acetate monomer and glass transition temperature (Tg) in the polymerization reaction is -10 It provides a method of producing a vinyl acetate-based adhesive composition comprising the step of adding and reacting 5 to 30% by weight of a vinyl acetate-ethylene emulsion of -20 ℃. In the emulsion polymerization of the polyvinyl alcohol and water, a general emulsifier used in the art may be used.

Of course, the polyvinyl alcohol and water in step a), and the vinyl acetate monomer and vinyl acetate-ethylene emulsion in step b) may be used in the same components and contents as described above.

In addition, the emulsion polymerization in step a) is preferably carried out at a temperature of 60 to 90 ℃, particularly preferably at a temperature of 70 ~ 85 ℃.

As described above, the vinyl acetate-based adhesive composition prepared according to the manufacturing method of the present invention does not use a plasticizer, so that after the low temperature or a long time passes, the plasticizer migrates to the inside of the adhered surface, thereby degrading adhesion and physical properties of the adhesive resin. In addition to solving the problem of reducing the adhesive strength caused by the additional input of winter phthalate plasticizer, and at the same time, environmentally friendly and human-friendly, adhesion, storage stability, water resistance, heat resistance, workability, especially water resistance and low temperature There is an advantage of excellent film forming properties.

Hereinafter, preferred examples are provided to help understanding of the present invention, but the following examples are merely to illustrate the present invention, and the scope of the present invention is not limited to the following examples.

EXAMPLE

Example 1

330 g of water was placed in a reactor equipped with a stirrer, and polyvinyl alcohol had 17 g of P24 (Dongyang Steel Chemical) having a degree of polymerization of 2400 and 88% of saponification, and P17 (Dongyang Steel) having a degree of polymerization of 1700 and 88% of saponification. Chemistry) 11 g, 9 g of AH22 (Nippon Gohsei) having a degree of polymerization of 2200 and 98% saponification, and polyoxyethylene nonylphenyl ether (HBL = 12.3) were added as an emulsifier. The mixture in the reactor was dissolved by raising the temperature to 80 ° C. while stirring at a stirring speed of 130 rpm. When the mixture in the reactor was completely dissolved, 100 g of EP706 (Air product) having a glass transition temperature of 0 ° C. was dissolved in a vinyl acetate-ethylene emulsion and 0.5 g of ammonium persulfate (APS, 98%, Junsei chem.) Was used as an initiator. While adding over time, 192 g of vinyl acetate monomers and 1 g of acrylic acid were added dropwise over 4 hours, and it reacted to produce the vinyl acetate type adhesive agent.

Example 2, and Comparative Examples 1 to 3

A vinyl acetate-based adhesive was prepared in the same manner as in Example 1, except that Example 1 was used as the component and the composition ratio shown in Table 1 below. In this case, the unit of Table 1 is g.

division Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Vinyl acetate monomer 192 192 220 220 180 Vinyl acetate-ethylene emulsion EP706 ¹ 100 - - - - AF401 ² - 100 - - - Polyvinyl alcohol P24 ³ 17 17 9 9 20 P20 ⁴ - - - - 15 P17 ⁵ 11 11 13 13 - AH22 ⁶ 9 9 - - - Monomer Acrylic acid ester - - - - 16 Acrylic acid One One - - 5 Plasticizer ⁷ - - 22 26 8 water 330 330 330 330 330 [Note] 1. EP706: Vinyl acetate-ethylene emulsion at Tg 0 ° C, Air products 2. AF401: Vinyl acetate-ethylene emulsion at Tg -15 ° C, Air products 3. P24: Polyvinyl alcohol with polymerization degree 2400, saponification 88%, Oriental Steelmaking Chemistry 4. P20: Polyvinyl alcohol with degree of polymerization 2000, 88% saponification, Dongyang Steel Chemical 5. P17: Polyvinyl alcohol with degree of polymerization 1700, 88% saponification, Tongyang Steel Chemical 6. AH22: Polymerization degree 2200, Gwa 98 % Polyvinyl alcohol, Nippon Gohsei 7. Plasticizer: dibutyl phthalate, Junsei chem.

The viscosity, solid content, glass transition temperature, and physical properties of the particle size of the vinyl acetate-based adhesives prepared in Examples 1 or 2 and Comparative Examples 1 to 3 were measured by the following methods, and the results are shown in Table 2 below. It was.

A) viscosity-measured using RION viscotester VT-04 at a temperature of 25 ° C.

B) Solid content-After drying for 30 minutes at 150 ℃, the amount was measured.

C) Glass transition temperature (Tg)-measured using DSC-2010 (TA instrument).

D) Particle size-was measured using a particle size analyzer (shinadzu SALD1100).

division Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Viscosity (cps) 28000 24000 25000 24000 86000 Solid content (%) 41.7 41.2 41.2 41.0 42.0 Glass transition temperature (℃) 38.62 35.43 18.59 15.60 21.31 Particle size (㎛) 2.58 2.41 3.12 3.23 3.16

As shown in Table 2, the adhesive of Example 1 or 2 according to the present invention showed a somewhat higher glass transition temperature compared to Comparative Examples 1 to 3, which is a conventional vinyl acetate-based adhesive, without using a plasticizer. Other viscosity, solid content, and particle size were confirmed to be similar.

In addition, the vinyl acetate-based adhesives prepared in Examples 1 or 2 and Comparative Examples 1 to 3 were respectively applied to both surfaces of 25 mm x 30 mm trees having a specific gravity of 0.5% or more and dried at a water content of 15% or less at 100 g / m 2. After bonding together, the mixture was compressed for 10 minutes under a load of 5 to 10 kgf / cm 2, and left at 20 ± 2 ° C. for 24 hours. After leaving for 48 hours after the pressure was removed, the water-resistant adhesion was measured, and the results are shown in FIG. At this time, the water adhesion strength was immersed in water of 30 ± 1 ℃ for 3 hours and immersed in water of 20 ± 1 ℃ for 10 minutes, and then UTM (shimadzu AG-2000A, universal testing equipment) was used as it is. The compressive shear strength was measured.

As shown in FIG. 1, the adhesive prepared in Examples 1 or 2 according to the present invention was found to have excellent water resistance compared to Comparative Examples 1 to 3 using a plasticizer. In addition, in the case of Comparative Example 2, it was confirmed that the water resistance was low by using a large amount of plasticizer compared to Comparative Example 1.

Further, the vinyl acetate-based adhesive prepared in Examples 1 or 2 and Comparative Examples 1 to 3 was widely applied to one surface on a clean slide glass, while maintaining a temperature of 0 to 10 ° C. and a humidity of 55 to 65%. It dried and formed the uniform film of 0.1-0.3 mm in thickness. Then, it was visually observed whether the dried product was a uniform continuous coating and whether the coating was cloudy. The results are shown in Table 3 below.

division Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Film film temperature (℃) > 5 > 0 > 5 > 4 > 5

Through Table 3, it can be seen that the higher the amount of plasticizer used, the better the low temperature film forming property. On the other hand, in the case of Example 1 or 2 according to the present invention by copolymerizing the vinyl acetate-ethylene emulsion and the vinyl acetate monomer showed a very good low-temperature film filmability, even at a high glass transition temperature, especially in the case of Example 2 aqueous adhesive It was confirmed that the film was formed up to 0 ° C. which is the limit of use.

In addition, in order to measure the storage stability of the vinyl acetate-based adhesive prepared in Example 1 or 2 after storage for one month at 50 ℃ is shown the result of measuring the viscosity change at 25 ℃ in Figure 2, stored at 4 ℃ for one month After the change in viscosity with time at 4 ℃ is shown in Figure 3 the results.

As shown in Figures 2 and 3, the adhesive of Example 1 or 2 prepared according to the present invention has almost no change in viscosity even after a period of time, and thus has excellent adhesiveness with the adhered surface and excellent storage stability. I could confirm it.

The vinyl acetate-based adhesive composition prepared according to the present invention does not use a plasticizer to solve the problem of lowering the adhesive strength and physical properties of the adhesive resin by migrating the plasticizer into the interior of the adherend after a low temperature or a long time, It is not only able to solve the problem of reducing adhesion due to the additional input of winter phthalate plasticizer, but also is environmentally friendly and human-friendly, and has excellent adhesion, storage stability, water resistance, heat resistance, workability, especially water resistance and low temperature film formation. There is.

Claims (7)

In the vinyl acetate adhesive composition, a) 10 to 50% by weight of vinyl acetate monomer; b) Vinyl acetate-ethylene emulsion 5 having a glass transition temperature (Tg) of -10 to -20 ° C. To 30% by weight; c) 1 to 30% by weight of polyvinyl alcohol; And d) 20 to 80% by weight of water Vinyl acetate-based adhesive composition comprising a. The method of claim 1, The vinyl acetate monomer (VAM) of a) is one type from the group consisting of acrylate acrylate, acrylic acid (CH ₂ = CHCOOH), ethylene, styrene, acrylate, and methacrylate. Vinyl acetate type adhesive composition used by copolymerizing with the monomer selected above. The method of claim 2, Vinyl acetate-based adhesive composition comprising the monomer is 0.1 to 20 parts by weight based on 100 parts by weight of vinyl acetate monomer. delete The method of claim 1, The vinyl acetate-based adhesive composition of the polymerization degree of the polyvinyl alcohol (PVA) of c) is 1500 to 3000 and saponification degree is 80 to 99%. The method of claim 1, The adhesive composition further comprises 0.001 to 3% by weight of an additive selected from the group consisting of a functional filler, a dispersant, an antifoaming agent, a stabilizer, a leveling agent, a gas absorbent, a moisture absorbent, a tackifier, and a catalyst. Vinyl acetate-based adhesive composition comprising. Emulsifying and polymerizing 1 to 30% by weight of polyvinyl alcohol in 20 to 80% by weight of water, and 10 to 50% by weight of vinyl acetate monomer and glass transition temperature (Tg) in the polymerization reaction are -10 to -20 ° C. A method of producing a vinyl acetate-based adhesive composition comprising the step of adding and reacting 5 to 30% by weight of a vinyl acetate-ethylene emulsion.

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