KR980009412A - Acrylic emulsion pressure-sensitive adhesive composition - Google Patents

Abstract

The present invention relates to an acrylic emulsion pressure-sensitive adhesive excellent in heat resistance characteristics and adhesiveness and capable of shortening the drying time by high molecular weight molecules.

The acrylic emulsion pressure-sensitive adhesive of the present invention can be produced by changing the composition of a monomer to appropriately change the glass transition temperature and polarity, using a monomer having a crosslinkable functional group, and appropriately using a tacky resin, a liquid rubber or a general solid rubber, And heat resistance, thereby providing an acrylic emulsion pressure-sensitive adhesive which can be used in fields requiring high adhesive force, cohesive force and heat resistance.

Description

Acrylic emulsion pressure-sensitive adhesive composition

The present invention relates to an acrylic emulsion pressure-sensitive adhesive, and more particularly, to an acrylic emulsion pressure-sensitive adhesive excellent in heat resistance characteristics and adhesiveness and capable of shortening a drying time by high-pressure type differentiation.

So far, water-dispersible pressure-sensitive adhesives have been used only in fields where adhesiveness and heat resistance are not required so much as they are deteriorated in view of performance such as adhesion and heat resistance, compared with organic solvent-type pressure-sensitive adhesives. However, the demand for cleanliness and cleanliness of the pressure- Accordingly, there is a growing demand for water-dispersible pressure-sensitive adhesives.

Therefore, the water-dispersible pressure-sensitive adhesive has been applied to the field of high-performance and high-performance pressure-sensitive adhesive, which has been used up to now, but the water-soluble pressure-sensitive adhesive has a problem of low water resistance, poor initial adhesion, In particular, it is known that there are many problems to be solved in order to apply the water-dispersible acrylic emulsion pressure-sensitive adhesive in a field requiring high cohesion and heat resistance while demanding a high adhesive force like automation.

Taking account of the above considerations, the present applicant has conducted intensive research to develop an acrylic emulsion pressure-sensitive adhesive which can be used in fields requiring high adhesion, cohesion and heat resistance. As a result, The present invention has been completed to develop an acrylic emulsion pressure-sensitive adhesive exhibiting cohesive strength and heat resistance.

The acrylic emulsion pressure-sensitive adhesive of the present invention can be produced by changing the composition of a monomer to appropriately change the glass transition temperature and polarity, and appropriately use a monomer having a cross-linkable functional group by appropriately using a tackifier resin, a liquid rubber or a general solid rubber, Cohesion and heat resistance can be exhibited.

Hereinafter, the present invention will be described in detail.

Examples of the monomers that can be used in the present invention include unsaturated carboxylic acid alkyl ester monomers such as methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, glycidyl methacrylate, dimethyl fumarate, Dimethyl maleate, dimethyl itaconate, monomethyl fumarate, monoethyl fumarate, 2-ethylhexyl acrylate, and the like.

As the alkenyl aromatic monomer, styrene, alpha-methylstyrene, vinyltoluene, divinylbenzene and the like can be used, and cyanuric acid such as acrylonitrile, methacrylonitrile, alpha-chloroacrylonitrile and alpha-ethyl acrylonitrile Vinyl monomers may be used.

In the present invention, an ethylenically unsaturated carboxylic acid monomer may be used in an amount of 1-10% of the total amount of monomers used for introduction of a carboxyl group into the molecular chain. Examples of the ethylenically unsaturated carboxylic acid monomer include acrylic acid, methacrylic acid, crotonic acid, Fumaric acid, itaconic acid, and the like.

As the monomer containing other hydroxyalkyl groups, there may be mentioned 2-hydroxyethyl acrylate, 2-hydroxymethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, hydroxybutyl acrylate, hydroxybutyl methacrylate (Ethylene glycol) maleate, di- (ethylene glycol) itaconate, 2-hydroxyethyl maleate, bis (2-hydroxyethyl) Maleate, 2-hydroxyethyl methyl fumarate and the like can be used. As the unsaturated carboxylic acid amide monomer, acrylamide, methacrylamide, N-methylol acrylamide, N-methylol methacrylamide, N, Acrylamide and the like can be used.

As the monomer containing an epoxy group, glycidyl acrylate, glycidyl methacrylate, methyl glycidyl acrylate, allyl glycidyl ether and the like can be used.

The polymerization reaction is not particularly limited as an initiator for emulsion polymerization by a conventional emulsion polymerization method, and any conventional emulsion polymerization initiator may be used.

The emulsifying agent is not limited, and anionic emulsifying agent, nonionic emulsifying agent, cationic emulsifying agent and a combination thereof can be used, but it is particularly preferable to use anionic emulsifying agent and nonionic emulsifying agent in combination.

These emulsifiers are preferably used in an amount of 0.1 to 20 parts by weight, more preferably 3 to 15 parts by weight, based on the monomers.

In the present invention, a liquid rubber, a solid rubber, a latex, or a tackifier resin may be used to improve adhesion or cohesion.

The acrylic emulsion pressure-sensitive adhesive composition produced by the present invention is a latex-type pressure-sensitive adhesive having a viscosity in the range of 500 to 50000 centipoise and is a pressure-sensitive adhesive for attaching a polyurethane sponge, EVA sponge, cotton or leather to metal surfaces such as iron, It can be used not only as a pressure sensitive adhesive for automobile but also as a pressure sensitive adhesive for automobile which requires heat resistance.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the Examples.

[Example 1]

A monomer emulsion is first prepared according to the composition shown in Table 1 in a six-necked separable reactor equipped with a stirrer, a condenser, a thermometer, a dropping funnel and a nitrogen injection device.

The emulsified solution was slowly added dropwise to the reactor over 4 hours, aged for 2 hours after the dropwise addition, and the reaction was terminated to synthesize an acrylic pressure sensitive adhesive.

[Example 2]

An acrylic emulsion pressure-sensitive adhesive was synthesized in the same manner as in Example 1, except that a terpene phenolic resin was used instead of an aromatic hydrocarbon resin as the tackifier resin in Example 1.

[Comparative Example 1]

Although the same method as in Example 1 was used, the composition of the monomer was different from that of Example, and methyl methacrylate 2, butyl acrylate 45, 2-ethylhexyl acrylate 52, acrylic acid 0.5 and glycidyl methacrylate 0.5 were used. An acrylic emulsion pressure-sensitive adhesive is synthesized without using a resin.

[Table 1] Synthetic conditions for Examples and Comparative Examples

(Measurement of physical properties)

(1) Adhesion

1) Initial adhesion

The urethane foam sheet and the Stainless-304 sheet were pressed together by hand and then measured 180 ° peel strength after 1 hour.

2) End-tack

The sample was prepared in the same manner as in the initial adhesion measurement, and after 24 hours, the 180 ° peel strength was measured in the same manner as in the initial adhesion measurement.

3) Specimen

① Material: Urethane foam sheet / Stainless-304 sheet

② Specification: 25 mm × 150 mm

(3) Peeling speed: 50 mm / min

(2) Shear Strength

The urethane foam sheet and the EDI coated steel sheet were pressed together by hand, and after 1 hour, the shear adhesive strength was measured. The cross section area was 25 mm × 25 mm.

(3) Heat resistance

A 50 × 100 mm urethane foam sheet was wound on a stainless steel-304 pipe having a diameter of 42 mm and allowed to stand at room temperature for 1 hour, then put into an oven at 100 ° C. and maintained for 1 hour to measure a distance (left and right average value).

(4) Heat-resistant creep property

50 x 150 mm2 urethane foam sheet and epoxy coated steel sheet were pressed by hand and allowed to stand at room temperature for 24 hours, then heated in an oven at 100 캜 for 1 hour without applying a load, and a load of 105 g was applied to the urethane foam Measure the distance of peeling of sheet and edged steel plate.

[Table 1] Comparison of physical properties for Examples and Comparative Examples

The acrylic emulsion pressure-sensitive adhesive of the present invention as described above can be obtained by changing the composition of a monomer to appropriately change the glass transition temperature and polarity, using a monomer having a crosslinkable functional group, and appropriately using a tackifier resin, a liquid rubber or a general solid rubber, Cohesive force, heat resistance, and the like, which is useful for applications requiring high cohesion, cohesion and heat resistance.

Claims (3)

In the acrylic emulsion pressure-sensitive adhesive, 50 to 90% of the viscous monomer is used alone or as a mixture thereof, 5-40% by weight of the cohesive monomer alone or as a mixture, 1-10% of the monomer having a carboxyl group as a reactive monomer for crosslinking, And 0.5 to 10% of a monomer having a hydroxyl group and 0.1 to 5% of a monomer having an amide group are used. The acrylic emulsion pressure-sensitive adhesive composition according to claim 1, wherein 1-20 parts of a liquid rubber, a solid rubber, a latex, and a tackifier resin are used for 100 monomers during polymerization. [3] The method according to claim 1, wherein the viscous monomer is 2-ethylhexyl acrylate, butyl acrylate or ethyl acrylate, the cohesive monomer is acrylonitrile, methyl methacrylate, styrene or vinyl acetate, And the like. Examples of the monomer having an epoxy group include glycidyl acrylate or glycidyl methacrylate or methyl glycidyl acrylate or allyl glycidyl ether and the like, Wherein the monomer having a hydroxyl group and an amide group is N-methylol acrylamide or N-butylol acrylamide. ※ Note: It is disclosed by the contents of the first application.