JPH0236206A - Crosslinking-type emulsion - Google Patents

Abstract

PURPOSE:To provide the title emulsion outstanding in safety and stability, capable of giving cured products of high resistance to heat and water, comprising two kinds of oil-in-water type emulsions of polymerizes (meth)acrylate incorporated with an organic peroxide and a reducing agent for organic peroxide respectively. CONSTITUTION:The objective emulsion comprising (A) an oil-in-water type emulsions made up of A1: at least one kind of a polymerizable (meth)acrylate >=200 deg.C in boiling point at normal pressure, having in one molecule two or more (meth)acryloyl groups and <=1,000 in molecular weight per (meth)acryloyl group and A2: an organic peroxide and (B) a second oil-in-water type emulsion made up of B1: at least one kind of a polymerizable (meth)acrylate >=200 deg.C in boiling point at normal pressure, having in one molecule two or more (meth) acryloyl groups and <=1,000 in molecular weight per (meth)acryloyl group and B2: a reducing agent for organic peroxide. This emulsion can further improve, e.g., adherability in combination with a polymer emylsion.

Description

Detailed Description of the Invention (a) Purpose of the Invention [Field of Industrial Application] The emulsion of the present invention has the property of rapidly crosslinking upon drying, and can be used alone as a paint or adhesive, and can also be used as a general-purpose emulsion. A cross-linked type that shows excellent effects such as improving the water resistance, solvent resistance, and adhesion of emulsion-type T materials and improving the heat resistance and adhesive strength of emulsion-type adhesives when added to polymer emulsions. It concerns emulsions.

[Conventional technology]

Polymer emulsions are widely used in paints and adhesives, but most of them are non-crosslinked, so
It has disadvantages such as poor water resistance, solvent resistance, and heat resistance.

In order to solve the above problems, various crosslinking agents such as N-methylol compounds and epoxy compounds have been used. N-methylol compounds such as N-methylol compounds and N-methylolmelamine are used as typical crosslinking agents, but problems in terms of environment and hygiene have been pointed out because they generate formalin gas. Epoquine compounds are also used as crosslinking agents to react with carboxy groups in polymer chains, but their poor stability in catalyst addition solutions may limit the working time after catalyst addition. . Some of the above-mentioned crosslinking agents require IJTI heat at a high temperature, and there is also the problem that their use on heat-sensitive substrates may be controlled because a predetermined temperature and time cannot be secured.

On the other hand, crosslinking of carboquino groups with polyvalent metals is known to proceed at room temperature, but this method cannot be applied to polymers in which no carboxyl group is present in the polymer, and the cured polymer has 11 aqueous and tolerable agents. It has not yet been possible to sufficiently improve sexual performance.

As mentioned above, the crosslinking agents conventionally used to crosslink polymer emulsions have problems such as insufficient safety or stability and high curing temperatures. A polymer emulsion that does not have the above problems and provides a cured product with excellent water resistance and solvent resistance is
It can be said that it is still unknown.

[Problems to be solved by the present invention] The present invention has excellent safety and stability, can be crosslinked at room temperature, and has excellent heat resistance when cured alone or in combination with other polymer emulsions. An object of the present invention is to provide a crosslinked emulsion that forms a cured product having water resistance, solvent resistance, etc.

(B) Structure of the Invention [Means for Solving the Problems] As a result of intensive research in order to improve the drawbacks of polymer emulsions as described above, the present inventors have discovered a polymerizable (meth) emulsion containing an organic peroxide. An emulsion consisting of an oil-in-water emulsion of acrylate (hereinafter referred to as (meth)acrylic oligomer) and an oil-in-water emulsion of (meth)acrylic oligomer containing an organic peroxide reducing agent is stable in an emulsified state. However, it has been discovered that by volatilizing the K content by drying after application, polymerization and crosslinking can occur at temperatures around room temperature, and the heat resistance, water resistance, solvent resistance, etc. of the cured product can be significantly improved. The present invention has now been completed.

The present invention relates to the following oil-in-water emulsion (A)
and the following oil-in-water emulsion (B).

(A) has two or more (meth)acryloyl groups in one molecule, and the molecular weight per (meth)acryloyl group is 10
00 or less, and the boiling point at normal pressure is 200'C
An oil-in-water emulsion containing a mixture of at least one of the above polymerizable (meth)acrylates and an organic peroxide as oil droplets.

(B) has two or more (meth)acryloyl groups in one molecule, and the molecular weight per (meth)acryloyl group is 10
00 or less, and the boiling point at normal pressure is 200'
7. An oil-in-water emulsion in which the oil droplets are a mixture of at least one polymerizable (meth)acrylate of C or higher and the organic peroxide reducing agent.

The present invention will be explained below.

In addition, in this specification, (meth)acrylate is
methacrylate and/or acrylate; (meth)acryloyl group refers to methacryloyl group and/or acryloyl group; (meth)acrylic acid refers to methacrylic acid and/or acrylic acid;
Or represents acrylic acid.

<Components> ○ (Meth)acrylic oligomer The (meth)acrylic oligomer in the present invention has two or more (meth)acryloyl groups in one molecule, and the molecular weight per (meth)acryloyl group is 1000 or less. and is a polymerizable (meth)acrylate having a boiling point of 200° C. or higher at normal pressure.

Examples of (meth)acrylic oligomers that can be used in the present invention include the following (a) to (e).

(a) Polyol Poly (meth)acrylate Usually polyalkylene glycol, polyhydric alcohol with 2 or more hydrides, and poly(meth)acrylate of polyhydric alcohols with alkylene oxide added to polyhydric alcohols with 2 or more hydrides, examples of which are: is polyalkylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)
Acrylate, inopentyl glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, tris(2) - (meth)acryloyl quinethyl) isocyanurate, tri(meth)acrylate of trimethylolpropane ethylene oxide adduct,
Examples include tri(meth)acrylate, which is a trimethylolpropane/propylene oxide adduct.

(b) polyester poly(meth)acrylate usually,
It can be obtained by esterifying polyhydric alcohol, polycarboxylic acid (anhydride) and (meth)acrylic acid, such as di(meth)acrylate of polyester diol of maleic acid and ethylene glycol. , di(meth)acrylate of polyester diol with phthalic acid and diethylene glycol, di(meth)acrylate of polyester diol with (anhydrous) tetrahydrofucric acid and diethylene glycol, di(meth)acrylate of polyester diol with adipic acid and triethylene glycol ) acrylate, and poly(meth)acrylate-I, which is a polyester polyol of (anhydrous) tetrahydrophthalic acid and trimethylolpropane.

(C) Epoxy (meth)acrylate Usually obtained from the reaction of epichlorohydrin with various phenol novolac resins obtained from epoxy resins having two or more epoxy groups in the molecule, phenol, cresol, phthylphenol, octylphenol, nonylphenol, etc. (meth)acrylic acid, carboxyl group-containing (meth)acrylate, or
(Meth)acrylic acid or carboxyl-bearing appearance (Meth)
It can be obtained by reacting a mixture of acrylate and polybasic acid, examples of which include di(meth)acrylate of bisphenol A diglycidyl ether, di(meth)acrylate of neopentyl glycol diglycidyl ether, and 16-hexane. Examples include di(meth)acrylate of thioldigrinone ether.

(d) Urethane (meth)acrylate polyhydric alcohol, polyvalent isocyanate and hydroxyl group-containing (
It can be obtained by reacting meth)acrylates, examples of which include organic polybasic acids such as adipic acid, sebacic acid, maleic acid, and terephthalic acid with ethylene glycol, propylene glycol, 14-butylene glycol, 1.6 - Polyester diol with polyhydric alcohol such as hexane diol and tolylene diisocyanate 1. Addition reaction products of diisonoanates such as s+,i'-diphenylmethane diisocyanate, hydrogen moiety carotolylene diisocyanate, isophorone diisonate, 16-hexamethylene diisocyanate and 2-hydroxyethyl (meth)acrylate, polypropylene glycol, poly Polyether diol such as tetramethylene glycol and tolylene diisocyanate, 4. =1'
Examples include addition reaction products of diisocyanates such as phenylmethane diisocyanate, hydrogenated tolylene diisocyanate, isophorone diisocyanate, and 16-hexamethylene diisocyanate and 2-hydroxyethyl (meth)acrylate.

(e) Other (meth)acrylates The following can be used as those that do not belong to (a) to (d) above.

Poly(meth)acryloyloxyphosphate, poly(meth)acrylate, etc.

The (meth)acrylic oligomers mentioned above can be used alone or in a mixture of two or more types.If the viscosity is high and causes trouble in handling, the (meth)acrylic oligomers mentioned above can be used. It may be diluted with a low-viscosity (meth)acrylic oligomer, or if necessary, other (meth)acrylic monomers may be added. In addition to (meth)acrylic acid, the (meth)acrylic monomers that can be used include (meth)acrylic acid, methyl (meth)acrylate, ethyl (meth)acrylate, Aroninox MIOI (trade name manufactured by Toagosei Chemical Industry Co., Ltd., hereinafter referred to as ), Aroninox M102.7
o There are acrylic acid esters such as Ninox M111.70, Ninox M 113, Aronix M114, Aronix M 17, and Aronix M120.

In addition, when using a (meth)acrylic oligomer having a high shallow water property, it is preferable to mix it with a lipophilic (meth)acrylic oligomer or a methacrylic oligomer.

Q Organic peroxide In the present invention, organic peroxides added to the (meth)acrylic oligomer include methyl ethyl ketone peroxide, cyclohexanone peroxide, 3,3.5-
Ketone peroxides such as trimethylcyclohexanone peroxide and methylcyclohexanone peroxide, L-butyl hydroperoxide, cumene hydroperoxide, diisopropylhenzene hydroperoxide and 25-dimethylhexane-2,5
Hydroperoxides such as -hydropergicide, peroxyesters such as mu-butyl perhenduate and mu-butyl perochine laure-1, and the like.

○Reducing agent The reducing agent for the organic peroxides added to the (meth)acrylic oligomer includes acetylacetone copper salt, acetylacetone vanadium (IV) m, acetylacetone cobalt salt, acetylacetone manganese salt, and acetylacetone iron (III). ) acetylacetone metal salts, such as salts,
Metal soaps such as iron naphthenate (n), cobalt naphthenate, manganese octylate, and cohal octylate, p
-1 luenesulfinic acid and its salts, L-ascolobic acid and its salts, 1,000 urea and its derivatives, acetic acid metal salts,
Examples include metal salts of benzoic acid. Among the transition agents, those that are not soluble in the (meth)acrylic oligomer are preferably dissolved in a solvent such as toluene, quinolene, or benzene, and then mixed with the (meth)acrylic oligomer. . Furthermore, it is also preferable to mix soylic acid, EDTA, dipyridyl, etc. with the (meth)acrylic oligomer as a stabilizer.

In the present invention, the amount of organic peroxide and its reducing agent added in each emulsion is determined by the amount of (meth) in the emulsion particles.
For the acrylic oligomer and other (meth)acrylic oligomers blended as desired, the amount of catalyst that is normally used to initiate radical polymerization may be used. As a combination of organic peroxide and its reducing agent,
In most cases, the crosslinking reaction will occur sufficiently with any component selected from the above listed components, but a combination using an organic peroxide such as hydroperoxide and a reducing agent containing vanadium (■) is particularly preferable. . Note that the organic peroxide and its reducing agent may be other than those mentioned above as long as stability is not impaired.

<Emulsification method> The crosslinked emulsion of the present invention can be prepared as follows.

That is, a (meth)acrylic oligomer to which an organic peroxide or its reducing agent has been added, in the presence of a surfactant,
By gradually adding water while stirring with a stirrer, an oil-in-water emulsion (A) or an oil-in-water emulsion (B) is obtained.

The emulsion (A) and emulsion (B) thus obtained are mixed in a desired ratio and uniformly stirred to obtain a crosslinked emulsion. Furthermore, it is also possible to use this crosslinked emulsion by adding it to a polymer emulsion.

O Surfactant Surfactants used to obtain the crosslinked emulsion of the present invention include polyoxyethylene alkyl ether, polyoxyethylene alkyl phenol ether,
Nonionic surfactants such as sorbitan fatty acid esters and polyoxyethylene acyl esters; anionic surfactants such as fatty acid salts, higher alcohol sulfate ester salts, alkylbenzene sulfones and alkylnaphthalene sulfonates; cationic surfactants ;Polymer surfactant;
There are water-soluble polymers and the like, and these can be used alone or in combination of two or more. Among the above-mentioned surfactants, it is particularly preferable to use a mixture of a nonionic surfactant having an HLB of 10 or more and a polymeric surfactant in order to obtain an emulsion with excellent stability.

<Desired Components> O Polymer Emulsion The cross-linked emulsion of the present invention can be used alone or by being added to and mixed with other general-purpose polymer emulsions. The polymer emulsion in this case is preferably one obtained by an emulsion polymerization method.

Examples of polymers include single polymers such as vinyl acetate polymers, vinyl acetate copolymers, butadiene polymers, styrene-phtadiene copolymers, acrylic polymers, vinyl chloride polymers, and vinyl chloride-vinyl acetate copolymers. Oil-in-water emulsions of polymers and copolymers can be used. In addition to the above, condensation polymers and condensation copolymers such as epoxy resins and alkind resins can also be used.

[Function] In the crosslinked emulsion of the present invention, when the organic peroxide contained in the emulsion (A) and the reducing agent contained in the emulsion (B) come into contact with each other, the redox catalyst system It has the characteristics that it quickly exhibits its function as an initiator, and that the crosslinking reaction proceeds at the contact interface of the emulsion particles.

Therefore, when the emulsion particles are emulsified and dispersed in water, the two types of emulsion particles do not come into contact with each other sufficiently to initiate a crosslinking reaction, so the emulsion exists as a stable emulsion, and the desired adherend is After being applied onto or onto an object to be coated, water is removed from the coating film by drying, and the emulsion particles come into sufficient contact with each other, and crosslinking reactions between and within the emulsion particles quickly occur.

[Reference Examples, Examples and Comparative Examples]

Hereinafter, the present invention will be explained in more detail using Reference Examples, Examples, and Comparative Examples.

Reference Example 1 (Preparation of cross-linked emulsion) Aro;・Nx M-7100 (3 parts by weight or less of cumene hydroperoxide (all parts by weight)) was uniformly dissolved.
103 parts of polyester acrylate (manufactured by Toagosei Kagaku Kogyo Co., Ltd.), 5 parts of Diskol N-501 (polymer surfactant, manufactured by Dai-Kogyo Seiyaku Co., Ltd.) and 2 parts of ion-exchanged water.
After weighing 5 parts into a 500 cc beaker, the mixture was sufficiently stirred at 70'C using a stirring motor.

Next, 10 parts of Emulgen 935 (polyoxyethylene nonylphenol ether surfactant, manufactured by Kao Atlas Co., Ltd.) was added and stirred thoroughly, followed by 200 parts of ion-exchanged water.
The mixture was stirred at 70° C. while gradually adding a portion dropwise to obtain an oil-in-water emulsion (A) containing an organic peroxide.

Further, Aroninox M-7100 in which 0.5 part of acetylacetone vanadium i was uniformly dissolved was used in the same manner as above to obtain an oil-in-water emulsion (B) containing a reducing agent for the organic peroxide.

Next, 100 parts of emulsion (A) and emulsion (B)
A crosslinked emulsion was obtained by uniformly mixing 100 parts at room temperature.

A coating film was formed using the crosslinked emulsion obtained as described above, and various properties were measured. The measurement method for each characteristic and the criteria for judging the results are as follows.

(1) Appearance of the emulsion A visual appearance inspection was conducted, and when there was no separation or sedimentation of the liquid, it was judged as "good", and when there was separation or sedimentation of the liquid, it was judged as "poor".

(2) After applying the curable crosslinked emulsion, dry the moisture at room temperature,
The adhesion of the coating film after being left for 0 minutes was evaluated by finger touch.

When the coating film had no tackiness, it was rated as "◎", and when the coating film had tackiness, it was rated as "x".

(3) Pencil hardness Measured according to JIS-H-8602, 4 and 8.

(・1) Make 100 square sections on the paint film by making base cuts with a width of 1 mm using an adhesive cutter knife, press sellotape (manufactured by Chihan Co., Ltd.) to the surface, and then peel it off. The evaluation was based on the number of eyes remaining when the test was completed.

(5) White (Toluene-based gauze was impregnated with toluene and rubbed, and then the degree of abnormality in the appearance of the coating film was visually determined.

(6) Water was dropped onto the water-resistant coating film, and the presence or absence of rust generation was visually determined after 24 hours.

Example 1 Five hours after the production of the crosslinked emulsion obtained in Reference Example 1, its appearance was visually inspected.

At this time, there was no liquid separation or sedimentation, and no thickening or gelation was observed, indicating stability. This cross-linked emulsion was applied to a steel plate using a 25 μm doctor blade, and then water was dried at room temperature. After drying, the coating film was allowed to stand for 30 minutes and inspected by touch, and found that there was no tackiness and that the coating film had been cured. Further, when the pencil hardness of this coating film was measured, it was 4H. A similar test was carried out one day after production.
I went after that. The results are shown in Table 1.

Example 2 20 parts of the crosslinked emulsion obtained in Reference Example 1 were added to 80 parts of a general-purpose acrylic emulsion (IE-478, manufactured by Rohm Anne Haas) and mixed. 25 pieces of steel plate base material
After coating with a .mu.m doctor blade, moisture was dried at 40.degree. C. using a hot air oven. After standing for 30 minutes, the pencil hardness, adhesion to a steel plate, toluene resistance, and water resistance of this coating film were measured using XK, and the results are shown in Table 2.

Comparative Example 1 The general-purpose acrylic emulsion (I
E-478, manufactured by Rohm and Haas) Example 2
The coating film was dried in the same manner as above, and the pencil hardness, adhesion to a steel plate, toluene resistance, and water resistance of the coating film were tested, and the results are shown in Table 2.

Table 1 Table 2 (c) Effects of the invention The crosslinked emulsion of the invention has excellent safety and stability, can be crosslinked at room temperature, and the cured product has excellent heat resistance, water resistance, solvent resistance, etc. However, when used in combination with a polymer emulsion, its adhesion, water resistance, solvent resistance, etc. can be significantly improved.

Claims (1)

[Claims] 1. A crosslinked emulsion comprising the following oil-in-water emulsion (A) and the following oil-in-water emulsion (B). (A) has two or more (meth)acryloyl groups in one molecule, and the molecular weight per (meth)acryloyl group is 10
00 or less and whose oil droplets are a mixture of at least one polymerizable (meth)acrylate and an organic peroxide having a boiling point of 200° C. or higher at normal pressure. (B) has two or more (meth)acryloyl groups in one molecule, and the molecular weight per (meth)acryloyl group is 10
An oil-in-water emulsion containing a mixture of at least one polymerizable (meth)acrylate having a boiling point of 200° C. or higher and a reducing agent of the organic peroxide as oil droplets.