JPS58225173A - Aqueous adhesive composition - Google Patents

Abstract

PURPOSE:An aqueous adhesive composition, consisting of an acrylic type emulsion containing an acrylic or methacrylic ester as a main component and a tackifier emulsion prepared by emulsifying a partially saponified polyvinyl alcohol (PVA) as an emulsifying agent, and having excellent water resistance. CONSTITUTION:An aqueous adhesive composition obtained by incorporating (A) 100pts.wt., based on the solid content, acrylic type emulsion containing an acrylic or methacrylic ester as a main component, preferably an emulsion of a copolymer of acrylic or methacrylic acid with the acrylic or methacrylic ester containing a metallic oxide or hydroxide, with (B) 15-200pts.wt. tackifier emulsion prepared by using 0.5-5.0pts.wt., based on 100pts.wt. tackifier resin, partially saponified polyvinyl alcohol (PVA) having preferably 70-95% saponification degree as an emulsifying agent, preferably rosin resin, pentaerythritol ester derivative of the rosin resin, etc. USE:Adhesives for rooftop waterproof sheets, roof heat insulating materials, and adhesives for air conditioners, automatic vending machines, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an aqueous adhesive composition, and more particularly to an aqueous adhesive composition having excellent water resistance and comprising an acrylic emulsion and a tackifier.

In general, water-based emulsion adhesives have various advantages over organic solvent-based adhesives, such as no air pollution, superior safety and hygiene, and resource conservation. There is a tendency to convert to emulsion type, but 1. It has the disadvantage of poor water resistance. In particular, acrylic emulsions are said to have better water resistance than other emulsions such as vinyl acetate emulsions, but when emulsified and blended with a tackifier, the water resistance decreases.

Therefore, in order to improve the water resistance of an aqueous adhesive composition formed by emulsifying and blending a tackifier into an acrylic emulsion, the present inventors conducted intensive research and found that when emulsifying the tackifier, the emulsifier Then, they discovered that when a tackifier emulsion using partially saponified polyvinyl alcohol is mixed with an acrylic emulsion, it is possible to obtain extremely excellent water resistance for a water-based adhesive, and this led to the completion of the present invention. Ta.

That is, the object of the present invention is to provide (1) an aqueous adhesive composition comprising an acrylic emulsion containing an acrylic ester or a methacrylic ester as a main component and a tackifier emulsion emulsified with partially saponified polyvinyl alcohol as an emulsifier. It's about doing.

The acrylic emulsion used in the present invention may be an emulsion normally used for this type of acrylic adhesive, and the ester groups include methyl, ethyl, butyl,
one or more acrylic esters or methacrylic esters having a 2-ethylhexyl, chrycidyl, 2-hydroxyethyl group, etc., one or more acrylic acids and methacrylic acids, and optionally monomers copolymerizable therewith, e.g. It can be produced by emulsion polymerization of styrene, vinyl acetate, ethylene, and divinyl compounds such as ethylene glycol diacrylate and polyethylene glycol dimethacrylate. Particularly preferred are copolymer emulsions of acrylic acid or methacrylic acid and acrylic esters or methacrylic esters containing metal oxides or hydroxides; It is commercially available under the trade name N-580. In this way, if (meth)acrylic acid containing a metal oxide or hydroxide is used and a divinyl compound is copolymerized.

Internal crosslinking occurs within the particles of the acrylic emulsion, improving the cohesive force of the polymer film after evaporation of the water in the aqueous dispersion medium.
This is desirable because it increases adhesive strength, especially when hot.

On the other hand, in the tackifier emulsion used in the present invention, the tackifier is partially saponified polyvinyl alcohol (hereinafter referred to as
%H emulsified with partially saponified PVA), 0.5% per 100 parts (weight) of tackifier.
It is appropriate to blend 5.0 parts. Of course, other nonionic or anionic surfactants may be used in combination as long as the desired water resistance is not impaired.

The tackifier emulsion is usually manufactured according to the following formulation.

For example, coumaron resin, phenolic resin, terpene resin, terpene phenolic resin, petroleum resin.

7. Tackifier selected from rosin resins and derivatives thereof, such as wotluene, benzene, and cyclohexane. It dissolves in water-insoluble organic solvents such as carbon tetrachloride at high concentrations, preferably at concentrations of 50% or more, while partially saponifying
After preparing and preparing a 20% aqueous solution, it was diluted with water to the appropriate amount, added to the above tackifier solution, and both were stirred at high pressure or high speed using a homogenizer (manufactured by Gauein) or a homomixer. , inverting the emulsion of the tackifier from a water-in-oil type to an oil-in-water type, and distilling off the organic solvent by stirring the resulting emulsion at a low speed while raising the temperature to 40 to 80°C under reduced pressure F, If necessary, it is then manufactured by filtration through about 80 mesh.

A particularly preferred emulsion uses a rosin derivative, particularly a pentaerythritol ester or glycerol ester derivative of rosin resin, as the tackifier, and partially saponified PVA as the emulsifier, which has a saponification rate of 70 to 95%, and has a molecular structure of acetic acid groups and hydroxyl groups. is produced using a polymerization degree of 1500 to 3000 in the form of a block copolymer.

Such preferred tackifiers are commercially available under the trade names Harimatsu, Harinister (made by Harima Kasei Kogyo Co., Ltd.), Ester Gum (made by Harima Kasei Kogyo Co., Ltd.), and Pencel (made by Arayo Kagaku Kogyo Co., Ltd.), and a preferable partially saponified PVA is Kuraray Boval PVA-217E.
, PVA-217EF.

It is commercially available as PvA-220E and PvA-224E (trade name manufactured by Kuraray).

The ratio of the acrylic emulsion and tackifier emulsion used is adjusted depending on the application.

The more tackifier is added, the lower the heat resistance will be, but adding 15 to 200 parts of tackifier to 100 parts (weight) of the solid content of the acrylic emulsion will improve adhesive strength, adhesive strength, and water resistance. Desirable in terms of gender etc.

In addition, the aqueous adhesive composition according to the present invention may contain a thickener, an antifoaming agent, a preservative and an antifungal agent, and a film forming aid depending on the purpose.

Antifreeze agent 2 A dispersant, a filler, a dye and a pigment may be blended, and a coagulant, a crosslinking agent, etc. may be blended as necessary.

The adhesive composition according to the present invention may be used in various applications for which acrylic adhesives were conventionally used, but because it has particularly excellent water resistance, it can be used as an adhesive for waterproof sheets and roof insulation materials in construction-related applications. It is useful not only as an adhesive for heat insulating materials such as air conditioners and vending machines where dew condensation may occur in electrical equipment, but also as an adhesive for automobile interior materials.

Hereinafter, the present invention will be explained in detail based on specific examples.

Production example Rosin chrycerol ester derivative (ester gum,
(manufactured by Arayo Kagaku Kogyo) in toluene to prepare a 70% toluene solution. On the other hand, partially saponified polyvinyl alcohol (Kuraray Boval PVA-220E, manufactured by Kuraray) 15
part was dissolved in 85 parts of water to prepare a 15% by weight PVA aqueous solution.

Next, 200 parts of the rosin derivative solution and 30 parts of the partial Kent polyvinyl alcohol aqueous solution are taken, 100 parts of water is added, and the mixture is stirred for 30 minutes at 800 rpm in a homomixer to obtain an oil-in-water emulsion.

The emulsion is heated to 60-70'C and stirred at low speed for 30 minutes under reduced pressure (approximately 40 mmHy) to distill toluene off. This was filtered through an 80-mesh mesh, and the solid content was 53.
．． Prepare a 0% tackifier emulsion.

Example Acrylic Emulsion 100 (Blymar N-580, manufactured by Rohm Schiars) Tackifier Emulsion 7゜ Preservative and anti-mold agent prepared in Production Example
o2 thickener
0.5 Zo 7 Sukesai “J
4.

A water-based adhesive composition is prepared by mixing the components listed in L.

Comparative Example As a tackifier emulsion, a sodium salt of a naphthalene sulfonic acid formaldehyde condensate (Demol N, manufactured by Hanadamaishi Ken Co., Ltd.) 0.89- and α-olefin sulfonated product was used instead of the partially saponified poly→nohynyl alcohol. Soda salt (Liporan 1400゜ Lion Oil Co., Ltd.) 1.0
An aqueous adhesive composition is prepared in the same manner as in the examples, except that y- is used as an emulsifier, and a product obtained in the same manner as in the above production example is used.

Test Examples Regarding the water-based adhesives obtained in the above Examples and Comparative Examples, ■solid content (component heated at 105°C/3 hours), ■pH
, ■Storage stability (placed in a 14Qcc glass bottle, sealed and left in 50'C atmosphere F for 7 days, and evaluated appearance such as separation and gelation), ■Normal adhesive strength (No. 9 cotton canvas (25X)
Apply approximately 300fj of adhesive to one side of the 100ml
Painted steel plate (25X100X) after 1 minute.
0.8 mm), dried for 7 days at 20°C/65% RH, measured the 18δ peel strength using an autograph (crosshead speed 200 m+n/min), and the ψ9 water resistant adhesive strength (prepared with ■, cured) The test pieces were immersed in 40'C water for 7 days, taken out and immersed in 20°C water for 1 hour, and then immediately tested for 180° peel strength. The results are shown in Table 1 below.

Table 1 As is clear from the results in Table 1, the Examples and Comparative Examples are similar in solid content, pH 1 storage stability, and normal adhesive strength, but there is a significant difference in water resistant adhesive strength.

Procedural amendment (voluntary) August 6, 1988 1. Indication of the case 1987 Patent Application No. 107953 2. Name of the invention Water-based adhesive composition 3. Person making the amendment Relationship to the case Patent applicant address Osaka 7-1 Akeda-cho, Takatsuki City, Prefecture Name Sunstar Giken Co., Ltd. 4 Agent 5 Date of amendment order Voluntary action 7 Contents of amendment (1) Page 8, line 3 of the specification, “Kent” has been changed to “saponification” and correct it.

+21st book, page 9, lines 6-7, “other than use” is 1
``Used,'' amended.

2. 1

Claims (1)

[Scope of Claims] (1) ■It is characterized by consisting of an acrylic emulsion whose main component is an acrylic ester or a methacrylic ester, and a tackifier emulsion emulsified with partially saponified polyvinyl alcohol as an emulsifier. Water-based adhesive composition. (2) The aqueous adhesive composition according to item (1), in which the partially saponified polyvinyl alcohol is in the form of a block copolymer with a saponification rate of 70 to 95eIy. (3) The aqueous adhesive composition according to item (1), which uses a rosin resin or a derivative thereof as a tackifier. (4) Part (1) using 15 to 200 parts of tackifier to 100 parts (by weight) of the polymer of the acrylic emulsion.
The aqueous adhesive composition described in item 1). (6) Part (2) using 0.5 to 5.0 parts of partially saponified polyvinyl alcohol to 100 parts (by weight) of the tackifier.
The aqueous adhesive composition described in item 1).