JPS58104948A - Aqueous emulsion composition of synthetic resin - Google Patents

Abstract

PURPOSE:To provide the titled composition having improved adhesivity, water resistance, heat resistance and cold resistance, excellent safety and good workability, and useful as an adhesive, etc., by compounding a polyisocyanate containing polydiene chain to an aqueous emulsion of a synthetic resin. CONSTITUTION:100pts.wt. of an aqueous emulsion of synthetic resin (e.g. acrylic ester polymer) having a resin content of 30-90wt%, preferably 40-80wt%, is compounded with 1-100pts.wt., preferably 3-30pts.wt. of a urethane prepolymer obtained by the reaction of (a) an isocyanate-containing urethane prepolymer containing polydiene chain in the molecular chain, e.g. a polybutadiene homopolymer especially having a viscosity of <=500 poise and a 1,4-bond content of >=50%, with (b) an organic polyisocyanate compound.

Description

[Detailed description of the invention] The present invention relates to synthetic resin aqueous emulsion compositions.

Synthetic resin aqueous emulsions have recently been widely used as adhesives for wood, paper, metals, various paints, and binders. Although this water-based emulsion solves the drawbacks of formalin residue in urea resin, elia melamine resin, and phenolic resin, as well as the environmental problems of compositions that use organic solvents, it has the major drawback of poor water resistance and heat resistance. be. Therefore, in order to overcome this drawback, many methods have been proposed for adding isocyanate compounds to synthetic resin aqueous emulsions.

However, since ordinary incyanate compounds are insoluble in water, their dispersibility is insufficient, and furthermore, the reaction between the isocyanate compound and water occurs rapidly, resulting in poor workability. Therefore, in order to improve these drawbacks, ■method using water-soluble incyanate compounds (
% Kaimei No. 53-56232) ■ Method of using an incyanate compound by dissolving it in a hydrophobic solvent (% Kaimei 50-691
No. 35) has been proposed. However, the former has an intermediate level of water resistance, and the latter poses new problems due to the use of solvents. On the other hand, a method of blending a water-soluble resin consisting of a liquid diene resin and an adduct of unsaturated carboxylic acids has been proposed (% Kaimei No. 52-69441), but this method does not improve water resistance or heat resistance. Not enough.

An object of the present invention is to provide an aqueous synthetic resin emulsion composition that eliminates the above-mentioned drawbacks. That is, the present invention is a synthetic resin aqueous emulsion composition comprising a synthetic resin aqueous emulsion and a polyisocyanate containing a polydiene chain.

The synthetic resin aqueous emulsion used in the present invention is an acrylic polymer such as a polymer of acrylic ester or a copolymer of the acrylic ester with vinyl chloride, methacrylic acid ester, acrylic acid, itaconic acid, maleic anhydride, etc. Coalescing; vinyl acetate polymers, copolymers of vinyl acetate with unsaturated alcohols such as acrylic acid, maleic acid, fumaric acid, and their esters, and copolymers of vinyl acetate and ethylene; Styrene-butadiene copolymer; acrylonitrile-butadiene copolymer; chloroprene; butyl rubber; polybutadiene; polyvinyl chloride;
Polyvinylidene chloride: means latex of synthetic resin such as polyvinyl alcohol. The synthetic resin content in these synthetic resin aqueous emulsions is usually 30 to 90% by weight.
, preferably 40 to 80% by weight. In addition, when forming an aqueous emulsion, a suitable surfactant can be added as appropriate. In addition, appropriate additives such as wheat flour, starch, carboxymethylcellulose, methylcellulose, Merck, clay, bentonite, wood flour, etc. may be added in a desired range considering the use of the synthetic resin aqueous emulsion composition. can.

Next, polyisocyanate containing a polydiene chain is an incyanate group-containing urethane prepolymer containing one polydiene chain in its molecular chain.

Here, the above polydiene chain-containing polyisocyanate is
Hydroxyl, amino, and imino groups at the end of the molecule.

It is a urethane prepolymer obtained by reacting a liquid diene polymer having active hydrogen groups such as carboxyl groups and mercapto groups with an organic polyisocyanate compound.

These liquid diene polymers have a number average molecular weight of 5
Di:1-ene polymers having 00 to 25,000 carbon atoms and having 4 to 12 carbon atoms, copolymers thereof, and also these gels.

There is a copolymer of carbon mono i- and an α-olefinic addition-polymerizable heptamer of carbon a2N22. Furthermore, when an unsaturated carboxylic group such as V-leic anhydride or its alligator conductor is added to these liquid diene polymers, it goes without saying that liquid diene polymers modified with K are included. Specific k) L-polybutadiene nemopolymer, polyisoprene homopolymer, butadiene-styrene copolymer.

Examples include butadiene-isoprene copolymer, butadiene-acrylonitrile copolymer, butadiene-2-ethylhexyl acrylate copolymer, butadiene-n-octadecyl acrylate copolymer, and the like. Among them, the viscosity is 2000 poise or less, more preferably 500 poise or less, and the chemical structure has 1.4 bonds with 50
Particularly preferred is the use of polymers with higher than 100% polymers.

In the present invention, a prepolymer is basically obtained by reacting this active hydrogen group-containing liquid diene polymer with an organic polyisocyanate compound, usually a diisocyanate compound, but other active hydrogen group-containing compounds may also be used in combination. It does not limit what you can do. However, their combined use must be controlled to such an extent that the prepolymer does not exhibit good water solubility.

Next, active hydrogen group-containing compounds that can be used in combination include ethylene glycol, propylene glycol,
, 4-butanediol, glycerin.

Low-molecular polyols such as trimethylolpropane, 1,2,6-hexanetriol, and pentaerythritol,
Amine compounds such as ethylenediamine, 4.4'-methylene-bis-2-riC1 loaniline, 4.4'-methylene-bis-2-ethylaniline, or low-molecular polyols or amine compounds, and fullkylenes such as ethylene oxide and propylene oxide. Examples of polyether polyols include propylene oxide adducts of bisphenol A, polyoxypropylene glycol, polyoxypropylene polyoxyethylene glycol, and ethylene oxide adducts of these polyols, which are obtained by addition polymerization of oxides. In addition, polyhydric alcohols such as ethylene glycol, phlopylene gelicol, and 1,4-butanediol, as well as phthalic acid, maleic acid, and malon
! Examples include polyester polyols, acrylic polyols, acrylic polyols, castor oils, tall oils, etc., which are condensation polymers with polybasic compounds such as amber, adipic acid, and terephthalate, and which have a hydroxyl group at the end.

Next, by reacting with the active hydrogen group-containing compound, a prepolymer,
Examples of the organic polyisocyanate compound from which - is obtained include tolylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, polymethylene polyphenyl polyisocyanate, liquid modified diphenylmethane diisocyanate, xylylene diisocyanate, cyclohexanephenylene diisocyanate, cyclohexyl diisocyanate, naphthalene - 1,5-diisocyanate, xylylene-z, 2'
-diisocyanate-, isopropylbenzene-2,4
- Diisocyanate, polypropylene glycol and tolylene diisocyanate addition reaction product.

Examples include addition reaction products with 1 mole of trimethylolpropane and 3 baskets of tolylene diisocyanate.

The reaction to obtain this isocyanate group-containing urethane prepolymer is usually carried out at a reaction temperature of 30°C under an inert gas flow such as dry nitrogen.
The reaction is carried out under conditions of ~100'C and a reaction time of 10 minutes to 10 hours. The incyanate group content of this prepolymer is usually 2 to 20% by weight, preferably 3 to 15% by weight.
The above-mentioned polyinsyanate containing a polydiene chain used in the composition of the present invention may be bonded with a blocking agent that masks the incyanate groups of the polyisocyanate in order to improve stability during storage. Including using blocked polyinocyanates. Phenol is the most common blocking agent here, and when a blocked diene chain-containing polyisocyanate is used, a cold-dissociating acupuncture agent such as aniline, triethanolamine, or ethylenediamine is used in combination.

1' The amount of the copper-containing polyisocyanate used in the present invention is 1 to 100 parts by weight, preferably 2 to 50 parts by weight, based on 100 parts by weight of the aqueous synthetic resin emulsion.
More preferably, it is used in an amount of 3 to 30 parts by weight. If it is less than 1 part by weight, the curability of the composition is poor and a homogeneous cured product cannot be obtained, and if it exceeds 100 parts by weight, curing is too rapid, which is not desirable. Therefore, the amount of polyinsyanate containing polydiene chains to be mixed may be appropriately selected depending on the purpose of use, method of use, etc. Note that it is possible to replace a part of the polydiene chain-containing polyisocyanate with a conventionally used water-soluble urethane prepolymer as long as the purpose and effects of the present invention are not impaired.

The synthetic resin aqueous emulsion composition of the present invention is prepared by mixing the above synthetic resin aqueous emulsion, polydiene chain-containing polyisocyanate, and additives added as required by appropriate means, such as manual stirring, a stirrer, a homogenizer, or a line mixer. is obtained.

The emulsion composition of the present invention has improved adhesive strength and water resistance, and also has remarkable improvements in heat resistance and cold resistance. Moreover, since there is no formalin odor and no solvent is used, there is no problem of environmental pollution, and the process is excellent in safety and workability. Furthermore, the emulsion composition of the present invention has excellent storage stability.

Therefore, the emulsion composition of the present invention is very useful as an adhesive, a pressure-sensitive adhesive, an adhesive, a binder, etc.

Next, the present invention will be explained in detail by way of examples.

Examples 1 to 3 and Comparative Example 1 Acrylic resin emulsion (manufactured by Saiden Chemical Co., Ltd., trade name: ER-7, viscosity 50 poise/30°C.

Add a predetermined amount of terminal incyanate liquid polybutadiene prebolymer to 100 parts by weight (non-volatile content: 50% by weight) (stir and mix, apply to steel plates, then stack the steel plates and bond. Then, at room temperature After curing for 7 days, the shear adhesive strength and hot water resistance were tested at various temperatures.The results are shown in Table 1.The dispersibility of the prepolymer during stirring and mixing was good.

This hydroxyl group-terminated liquid polybutadiene is partially MDI (4,4
'-diphenylmethane diisocyanate) Preboly-1 (viscosity 850 poise/35"C.

NOO content 9% by weight) Pheasant number average molecular weight: 2800° Viscosity = 50 voids/30°C.

Hydroxyl group content: 0.83 rneq/9.

Microstructure Nidorans-1e4'60%.

Cis-1,4: 20%, Vinyl-1,2: 20% Table 1 Example 4. Comparative Example 2 Vinyl acetate resin emulsion (manufactured by Cemedine (n), trade name: Why) 605. A predetermined amount of liquid polybutadiene prebolymer with terminal isocyanate (same as in Example 1) was added to 100 parts by weight (non-volatile content: 50% by weight), stirred and mixed well, applied to a cotton cloth, and then adhered to a piece of wood as an adherend.

After curing for 3 days at room temperature, 180 degree beer adhesive strength and water resistance tests were conducted at each temperature. The results are shown in Table 2.

Note that the prepolymer was easily dispersed during mixing and stirring.

Table 2

Claims (1)

[Claims] A synthetic resin aqueous emulsion composition prepared by blending a polydiene chain-containing polyisocyanate into a synthetic resin aqueous emulsion.