JPS6011502A - Aqueous synthetic resin dispersion - Google Patents

Abstract

PURPOSE:An aqueous synthetic resin dispersion excellent in adhesiveness, obtained by polymerizing a monomer mixture comprising vinyl chloride, vinyl acetate, and a specified compound in an aqueous medium in the presence of a vinyl chloride-soluble urethane polymer. CONSTITUTION:100pts.wt. monomer mixture comprising vinyl chloride, vinyl acetate, and an alkali metal or ammonium salt of allylsulfonic acid or methallylsulfonic acid and, optionally, other compolymerizable monomers is polymerized in an aqueous medium in the presence of 2-50pts.wt. vinyl chloride- soluble urethane polymer. When the amount of the urethane polymer is below 2pts.wt., the adhesive strength of the dispersion is low in bonding carried out at a temperature <=80 deg.C, and the tear strength of a film is low when used as a semi-adhesive coating, which is undesirable. On the contrary, when the amount of the urethane polymer exceeds 50pts.wt., the water and oil resistances are poor.

Description

[Detailed description of the invention] The present invention relates to a synthetic resin aqueous dispersion.

Conventionally, synthetic resin emulsions such as vinyl acetate/vinyl chloride, diene, and acrylic acid esters have been used as adhesives for paper, wood, textiles, concrete, etc., and are known for their ease of handling, safety, and low cost. Therefore, it has been widely used, but it lacks adhesive strength to plastics or metals, has poor water resistance and oil resistance, and has low tear strength on the adhesive surface, especially when adhering to these substrates. Ta.

For this reason, when the purpose is to adhere to plastics or metals, thermosetting resins such as epoxy resins, phenol resins, or urethane resins have been used as solutions in organic solvents.

These are complicated and expensive to handle, and are also prone to ignition and combustion, making them extremely unsatisfactory for use. In addition, especially when vinyl acetate/vinyl chloride emulsions are used, water resistance, solvent resistance, or heat resistance are insufficient, and even if these improvements are impossible, for example, phenol resins, urethane resins, formalin resins, etc. When attempts were made to improve the composition by mixing water-soluble amino acid resins, etc., there was almost no effect, and excessive thickening or coagulation was observed, resulting in poor practicality.

The present invention aims to provide a synthetic resin aqueous dispersion with excellent adhesive properties, which eliminates the drawbacks of the conventional art.

That is, in the present invention, based on 100 parts by weight of the monomer mixture described below,
Vinyl chloride, vinyl acetate, and an alkali metal or ammonium salt of allylsulfonic acid or methallylsulfonic acid (hereinafter collectively referred to as (meth)allylsulfonic acid) in the presence of 2 to 50 parts by weight of a urethane polymer soluble in vinyl chloride. and, if desired, a monomer mixture consisting of other copolymerizable monomers,
It is a synthetic resin aqueous dispersion that is polymerized in an aqueous medium.

The synthetic resin aqueous dispersion of the present invention exhibits extremely excellent adhesion to plastics, metals, wood, etc., does not require the addition of a curing catalyst, can be stored for a long time as a liquid type, and has low cost. It exhibits strong adhesive strength through heat treatment, and provides a coating with excellent water resistance, solvent resistance, and tear strength, making it suitable for flocking or raw adhesive coating for the purpose of preventing pollution. However, these effects are thought to be due to the complex mutual effects of the monomer components and copolymer 1η components constituting this synthetic resin dispersion.

The proportion in the vinyl chloride tetramer mixture, which is the first component in the monomer mixture in the present invention, is 15 to 90% by weight.
The range is preferably 30 to 85% by weight, and more preferably 30 to 85% by weight.

If it exceeds 90% by weight, the resulting copolymer will not only become too hard, but also tend to have poor adhesive strength. On the other hand, if it exceeds 15% by weight, it will tend to have poor adhesion to plastics or metals. , the proportion of vinyl acetate monomer as the second component in the monomer mixture is preferably in the range of 5 to 80% by weight, and 1
More preferably 5 to 65% by weight.

If it exceeds 80% by weight, the solvent resistance of the resulting copolymer will decrease,
Water resistance or adhesion to metals tends to decrease, and on the other hand, if it is less than 5% by weight, the adhesiveness decreases significantly and the adhesion to various materials tends to be poor.

Further, the proportion of the alkali metal or ammonium salt of (meth)allylsulfonic acid, which is the third component, in the monomer mixture is preferably in the range of 0.1 to 5.0% by weight, and preferably 0.2 to 5.0% by weight.
4.0% by weight is more preferred.

If it exceeds 5.0% by weight, the water resistance of the resulting synthetic resin aqueous dispersion tends to be poor, while if it is less than 0.1% by weight, the adhesion to various substrates tends to decrease; The storage stability of the aqueous dispersion becomes poor and sediments tend to form.

Furthermore, as a desired component, a monomer copolymerizable with each of the above-mentioned monomers can be used in an amount preferably not more than 40 ffi, more preferably not more than 20% by weight.

As such copolymerizable monomers, for example, when imparting flexibility, unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, fumaric acid and ethyl alcohol, phthyl alcohol, 2-ethyl Hexylalco・
vinyl ethers such as butyl vinyl ether, octyl vinyl ether, and lauryl vinyl ether; vinyl esters of isomers of vinyl valerate and pelargonic acid; vinyl esters of fatty acids such as vinyl laurate, vinyl stearate, and vinyl oleate. Esters etc. can be used.

In addition, in order to impart crosslinking properties, self-crosslinking monomers such as glycidyl methacrylate, N-methylol acrylamide, diallyl phthalate, and divinylbenzene, or crosslinking aid monomers such as acrylic acid, methacrylic acid,
Itaconic acid, maleic acid, hydroxyethyl acrylate, acrylamide, etc. can be used.

Furthermore, in order to adjust the compatibility with other types of polymers, e.g. evaporated ethylene, propylene, methacrylonitrile or acrylonitrile can be used in combination.

The polymerization method in the present invention may be a conventionally known polymerization method in an aqueous medium, but is not particularly limited. The emulsifier used is alkylaryl sulfonate,
Examples include polyoxyethylene alkylaryl sulfates and alkali salts of succinic acid half esters. Examples of protective colloids used include polyvinyl alcohol, alkyl cellulose, and hydroxyalkyl cellulose. Catalysts used include potassium persulfate, ammonium persulfate, hydrogen peroxide, and the like.

Next, the urethane polymer soluble in vinyl chloride monomer used in the present invention does not substantially contain hard segments, has a molecular stitch of 300 or more, preferably 500 or more, and has O at both ends.
Although it can be obtained from a dihydric alcohol having an H group and a polyisocyanate having NGO groups at both ends, a urethane polymer containing many urethane bonds is preferable.

When a urethane polymer is dissolved in the monomer mixture and emulsion copolymerized, the urethane polymer has surfactant-like properties, and the amount of emulsifier used can be reduced, resulting in good stability. It is possible to obtain an aqueous dispersion and to perform so-called non-soap emulsion copolymerization. Also,
Physical properties such as peel strength and tear strength can be improved.

The ratio of the monomer mixture to the urethane polymer is 2 parts by weight of the urethane polymer per 100 parts by weight of the monomer mixture.
~50 parts by weight is required.

If the amount of urethane polymer used is less than 2 parts by weight, 80
The adhesive strength is low under bonding conditions by heating at temperatures below .degree. C., and when used as a ready-adhesive coating material, such as a strippable coating material, the tear strength of the film is low, making it unsuitable. If the amount of the urethane M combined exceeds 50 parts by weight, the water resistance and oil resistance will be poor. However, it is a urethane polymer, and when used as an adhesive, it has excellent physical properties such as peel strength and tear strength.

Next, the present invention will be explained in more detail with reference to Examples and Comparative Examples. (Hereinafter, parts refer to parts by weight.

) In each example, parts mean parts by weight, and the physical properties were evaluated by the following method. -(1) Peel strength: 100 to 120 gr/n of synthetic resin emulsion as a solid content in Tetron/cotton (65/35) blended fabric? Apply it evenly so that
JX Bonded for 20 minutes, 18 at 20% width
Peel strength at 0° was measured.

(2) Solvent resistant smooth melamine resin plate with solid content of 50-70 gr
/rr? Apply synthetic resin emulsion so that 1
It was dried at 20° C. for 2 minutes to form a film on the surface of the resin plate. Urethane resin lacquer (concentrated 20% by weight) using toluene as a solvent has a total solid content of 50 to 70%.
gr/m' and left at 23°C for 2 days and nights, the degree of contamination of the urethane resin to the resin plate was observed and evaluated.〇(3) Measurement of water resistant peel strength After immersing the test substrate prepared for L in pure water at 20° C. for 2 days, the peel strength was measured, and the peel strength was divided by the strength before immersion to calculate the retention rate.

(4) Tear Strength The tear strength at 180° of the scratch metal insert was measured on the same bonded base material as the test piece prepared for measuring the peel strength in (1).

(5) Mechanical stability The presence or absence of aggregate formation is observed using a Maron type mechanical stability tester at 1000 rpm for 5 minutes.

Examples 1 to 4 and Comparative Example 1 In a 5-t stainless steel polymerization vessel, 140 parts of pure water and 100 parts of the monomer mixture shown in Table 1 were mixed with fPVA-1 without a dispersant.
217 (average polymerization rate: 1730. degree of saponification: 88 molti, manufactured by Kuraray ■) 0.4 part and Lebenol WZ (anionic emulsifier, manufactured by Kao Atlas ■) 'ff, 0.5 part, potassium persulfate as a catalyst. 0.10 parts and 10 parts of a urethane polymer soluble in vinyl chloride monomer (polymer listed in Table 1) were charged and heated at 60°C for 60 minutes at 400r, p, rrb.
After that, polymerization was carried out for 20 hours until the internal pressure of the autoclave was ff105. The reaction was carried out to Kg/d (absolute pressure).

The evaluation results of the obtained synthetic resin aqueous dispersion are also listed in Table 1.

Comparative Example 2 A synthetic resin aqueous dispersion was obtained in the same manner as in Example 1 except that no polymer was used. The physical property measurement results are shown in Table 1.

0

Claims (1)

[Claims] 1. In the presence of 2 to 50 parts by weight of a urethane polymer soluble in vinyl chloride based on 100 parts by weight of the phosphor mixture described below,
A monomer mixture consisting of vinyl chloride, vinyl acetate, an alkali metal or ammonium salt of allylsulfonic acid or methallylsulfonic acid, and optionally other copolymerizable drugs is polymerized in an aqueous medium [7]. water dispersion.