JPS5837337B2 - copolymer emulsion - Google Patents

Description

[Detailed description of the invention] The present invention relates to copolymer emulsions.

Specifically, the present invention relates to an aqueous acrylic copolymer emulsion that can be crosslinked and cured with oxygen in the air by adding a metal dryer.

In recent years, water-based resins have attracted attention because they are pollution-free and resource-saving.

In particular, aqueous emulsions are promising as paint resins because they hardly use organic solvents or organic amines.

However, most aqueous emulsions are thermoplastic resins, which are extremely inferior in terms of hardness, solvent resistance, water resistance, corrosion resistance, etc., when compared with the properties of organic solvent-based resins.

Thermosetting water-based emulsions are also being developed;
In most cases, heating to 130 to 180°C or higher is required, which is not sufficient to be used as a general-purpose paint resin.

On the other hand, oxidative polymerization type alkyd emulsions are commercially available, but the initial drying properties of alkyd emulsions are insufficient, and furthermore, there are problems with coating film properties, hardness, and stain resistance after curing. .

Therefore, the object of the present invention is to provide an acrylic copolymer emulsion that can be crosslinked and cured by baking at room temperature or at a low temperature for a short time.

By introducing an allyl group into an acrylic copolymer obtained by copolymerizing dicyclopentadiene derivatives such as dicyclopentadiene acrylate or methacrylate, the present inventors have developed an acrylic copolymer that can be cured at room temperature or at low temperature in a short time. It was discovered that an emulsion can be obtained, leading to the present invention.

The acrylic emulsion obtained by the present invention has water resistance, solvent resistance, corrosion resistance, and
It has weather resistance and other physical properties.

That is, the present invention provides the following conditions: (wherein R is hydrogen, lower alkyl, or halogen.

) 2 to 30 parts by weight of a dicyclopentadiene derivative represented by. (B) 3 to 20 parts by weight of α,β monounsaturated monomer having a hydroxyl group, (C) α, which can be copolymerized with (A) and (81 components);
β-monounsaturated monomer (4) to (1) total of io
o parts by weight, copolymerized, and (D) partial allyl ether of polyhydric alcohol having a terminal incyanate group obtained by reacting partial allyl ether of polyhydric alcohol with diisocyanate 2 to 20 parts by weight. The present invention relates to a copolymer emulsion containing copolymer (1) and water (II) obtained by blending and reacting parts by weight.

Component (4) includes dicyclopentadiene acrylate, dicyclopentadiene methacrylate, dicyclopentadiene-α-chloroacrylate, and the amount used is 2 to 30 parts by weight.

If it is less than 2 parts by weight, the curability will be insufficient, and if it exceeds 30 parts by weight, the coating will become brittle (poor flexibility).

Preferably it is 5 to 10 parts by weight.

In addition, the compound represented by the above general formula (1), which is the component (A), also has the general formula (1
) The compound represented by dicyclopentadiene and general formula (II) (wherein, R is the same as in general formula (1)).

) can be obtained by addition reaction of a carboxylic acid represented by the general formula (B (however, the -OH group is bonded to the 58 or 9 position).

) can be obtained by subjecting the compound represented by formula (1) to an esterification reaction with the carboxylic acid represented by general formula (1).

Component (B) includes β-hydroxyethyl acrylate, β-hydroxyethyl methacrylate, β-hydroxypropyl acrylate, β-hydroxypropyl methacrylate, 1,4-butanediol monoacrylate, 1,4-butanediol monoacrylate, Acrylate, 1,6
-hexanediol monoacrylate, 1,6-hexanediol monomethacrylate, etc.

The amount used is 3 to 20 parts by weight; if it is less than 3 parts by weight, the reaction with component (D) will be insufficient, and if it exceeds 20 parts by weight, it will adversely affect the water resistance of the coating film.

Component (C) includes unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, fumaric acid, and crotonic acid, methyl acrylate, ethyl acrylate, n-propyl acrylate, isobutyl acrylate, 2-ethylhexyl acrylate, etc. acrylic esters, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate. Methacrylic acid esters such as n-butyl methacrylate, isobutyl methacrylate, and 2-ethylhexyl methacrylate, styrenic monomers such as styrene, vinyltoluene, and α-methylstyrene, and other vinyl acetate, vinyl propionate, glycidyl acrylate, and methacrylate. One type or a combination of two or more types of acid glycidyl, acrylamide, methacrylamide, acrylonitrile, methacrylonitrile, n-methylolacrylamide, n-butoxymethylacrylamide, etc. can be used.

When an unsaturated carboxylic acid is used as component 0, it is preferably used in an amount of 4 parts by weight or less, particularly preferably 1 to 2 parts by weight, based on 100 parts by weight of the total amount of components Q.

Component (D) is a dihydric alcohol monoallyl ether such as ethylene glycol monoallyl ether, diethylene glycol monoallyl ether, propylene glycol monoallyl ether, ■,4-butanediol monoallyl ether, and ■,6-hexanediol monoallyl ether. Allyl ether, trimethylolethane diallyl ether,
Partial allyl ethers of polyhydric alcohols, such as trivalent alcohol diallyl ethers such as trimethylolpropane diallyl ether and glycerin diallyl ether, and tetrahydric alcohol triallyl ethers such as pentaerythritol triallyl ether, which have one hydroxyl group. What remains is a diisocyanate such as toluene diisocyanate, xylene diisocyanate, hexamethylene diisocyanate, diphenylmethane diisocyanate, or tetramethylene diisocyanate, and the hydroxyl group of the partial allyl ether of the polyhydric alcohol is reacted with the isocyanate group of the diisocyanate. Preferred are compounds obtained by reacting to form a urethane bond and leaving one terminal incyanate group.

Particularly preferred is a compound in which one molecule of toluene diisocyanate is bonded to one molecule of trimethylolpropane diallyl ether.

The amount of component (D) used is 2 to 20 parts by weight.

If the amount is less than 2 parts by weight, crosslinking will be insufficient, and if it exceeds 20 parts by weight, the initial drying performance will be poor.

Preferably it is 5 to 15 parts by weight.

Component (D) may be obtained by reacting a partial allyl ether of a polyhydric alcohol with two or more remaining hydroxyl groups with a polyhydric incyanate such as a diisocyanate, but the above-mentioned ones are preferred.

above. As for the component 0), it is preferable to have one incyanate group in the molecule, but for this reason, partial allyl ethers of polyhydric alcohols and diisocyanates are such that the OH group of the former and the NCO group of the latter are OH/NOC. It is preferable to react at an equivalent ratio of 1/2 to 1/2.2.

When it exceeds 1/2, unreacted diisocyanate tends to remain, and when it is less than 1/2.2, compounds in which partial allyl ether of a polyhydric alcohol is bonded to both ends of the diisocyanate through urethane bonds increase.

Mata, as partial allyl ether of polyhydric alcohol,
It is preferable that 90% by weight or more contains one hydroxyl group in the molecule, and 10% by weight or less contains two or more hydroxyl groups in the molecule.

The copolymer emulsion according to the present invention can be obtained by polymerization using a known method.

For example, in emulsion polymerization, the polymerization temperature is 0°C to 100°C, preferably 50 to 80°C.

Radical-releasing catalysts are used as polymerization catalysts, and redox systems such as potassium persulfate and sodium metabisulfite are particularly effective.

As the emulsifier, anionic surfactants, cationic surfactants, nonionic surfactants and amphoteric ionic surfactants can be used, and protective colloids such as polyvinyl alcohol starch dextrin, methyl cellulose and carboxymethyl cellulose can also be used.

Although it is not necessary to use these emulsifiers, it is generally better to use them, and in this case, it is recommended that they be used in an amount of 0.1 to 5% by weight based on the total of components (4) to (C'). preferable.

Carbon tetrachloride, mercabutanes, and organic solvents may be used to adjust the molecular weight of the copolymer.

The copolymer produced by emulsion polymerization usually uses an acidic catalyst, and in some cases a carboxyl group is present in the copolymer, so it shows a pH value of 2 to 6, but it can be used as it is as component (D). may be added and reacted, but the stability of the emulsion will be increased if it is added after the pH is made neutral or alkaline to about 7 to 10.

Examples of alkaline substances added to make it neutral or alkaline include aqueous ammonia, dimethylamine, triethylamine, morpholine, triethanolamine, and dimethylaminoethanol.

Subsequently to the above milk compound, component (D) is added, and (
The incyanate group of component D) and (4), (B) and (
Hydroxyl groups in the copolymer of component C) can be reacted.

This is sufficiently accomplished at 60-80°C for 2-6 hours.

There are no particular restrictions on the amount of water used, but if the solid content is 70
It is preferable that the amount is 40 to 60% by weight or less, particularly 40 to 60% by weight.

If the solid content is too high, the stability of the emulsion will deteriorate.

In addition, the copolymer emulsion according to the present invention can be prepared by dissolving (A) CB) and (C) components in a water-soluble organic solvent, for example, a solvent having no hydroxyl group such as cellosolve acetate, such as penzoyl peroxide. It can also be obtained by carrying out solution polymerization using a peroxide or an azobis catalyst such as azobisisobutyronitrile, reacting the component (D), and adding water and an emulsifier to form an emulsion.

When polymerizing using an organic solvent, the amount of organic solvent used is such that after adding water, the solid content is 50% by weight or less, preferably 25 to 40% by weight, and the same weight as water or less. Preferably.

The copolymer emulsion according to the present invention can be applied to metal driers such as cobalt naphthenate, lead naphthenate, zinc naphthenate, zirconium naphthenate, cobalt octenoate,
By adding one type or a combination of two or more of lead octenoate, zinc octenoate, zirconium octenoate, etc., it is possible to make an emulsion paint that hardens at room temperature.

The amount added is based on 100 parts by weight of resin solids as the amount of metal.
o. oi~1 part by weight.

In some cases, some peroxides such as t-butyl peroxyoctoate, penzoyl peroxide, t-butyl peroxybenzoate, etc. are added.

The amount added is 0 to 1 part by weight. This emulsion paint can be used as is, but it is recommended to add pigments, solubilizers, solvents, colorants, etc., or to mix it with a wide range of water-soluble or water-dispersible resins such as modified amino resins, epoxy resins, and acrylic resins. is also possible.

This emulsion is further made into a paint using commonly used pigments, surface treatment agents, organic solvents, etc.

Paint compositions can be painted by dipping, brushing, spraying, roll coating, etc., and can be applied to wood, paper, fibers, plastics, ceramics, iron, non-ferrous metals, and similar materials. can be painted on the surface.

Example 1 100 g of ion-exchanged water was placed in a flask equipped with a stirrer, thermometer, reflux condenser, dropping funnel, and inert gas inlet.
, 1 g of sodium lauryl sulfate is charged, and the temperature of the flask is raised to 70 to 80° C. under a nitrogen gas stream.

Next, ■ A solution in which 0.5 g of ammonium persulfate was dissolved in 20.9 g of water, 5 g of dicyclopentadiene methacrylate, 5 g of β-hydroxyethyl methacrylate, 39 g of methyl methacrylate, and 50 g of butyl acrylate.
A mixture of 1 g of acrylic acid and 1 g of acrylic acid was separately added dropwise over 2 hours.

The flask is always maintained at 70 to 80°C, and after the completion of the dropwise addition, the reaction is continued for an additional 2 hours to complete the polymerization.

The polymerization rate was 98% by weight or more. The acrylic copolymer emulsion thus obtained was adjusted to pH with aqueous ammonia.
Adjusted to 7.

The emulsion obtained here contains 1 mol of trimethylolpropane diallyl ether and 1 mol of toluene diisocyanate.
Slowly add 5g of the solution in which the moles were reacted, and heat at 60℃ for 4 hours.
Allowed time to react.

This emulsion had a heating residue of 46% by weight and a viscosity of 335 PS as measured by a B-type rotational viscometer at 25°C.

Example 2 10 g of dicyclopentadiene methacrylate and 5 g of β-hydroxyethyl methacrylate were prepared in the same manner as in Example 1.
, methyl methacrylate 34g, butyl acrylate 5
A copolymer acrylic emulsion containing 0 g of acrylic acid and 1 g of acrylic acid was prepared.

The polymerization rate was 98% by weight or more.

This emanolenyon was reacted with 10 g of a reactant of 1 mol of trimethylolpropane diallyl ether and 1 mol of toluene diisocyanate in the same manner as in Example 1 to obtain a room temperature curable acrylic copolymer emulsion.

This emulsion has a heating residue of 48% by weight and a viscosity of 25°C.
It was 52 PS.

Comparative Example 1 An acrylic copolymer emulsion was produced in the same manner as in Example 1 using 49 g of methyl methacrylate, 1-50 g of butyl acrylate, and 1 g of acrylic acid.

This emulsion was adjusted to pH 8 with aqueous ammonia.

Comparative Example 2 10 g of dicyclopentadiene methacrylate and 5 g of β-hydroxyethyl methacrylate were prepared in the same manner as in Example 1.
, methyl methacrylate 34g, butyl acrylate 5
0 g and 1 g of acrylic acid were emulsion copolymerized.

The resulting emulsion was adjusted to pH 8 with aqueous ammonia.

Comparative Example 3 An acrylic copolymer emulsion was produced in the same manner as in Example 1 using 5 g of β-hydroxyethyl methacrylate, 44 g of methyl methacrylate, 50 g of butyl acrylate, and 1 g of acrylic acid.

The pH of this emulsion was adjusted to 7 with aqueous ammonia, and 10 g of a reaction product of trimethylolpropane diallyl ether and toluene diisocyanate was added, and the mixture was reacted at 60° C. for 4 hours.

Paints were prepared using Examples 1 to 2, Comparative Examples 1 to 3, commercially available acrylic emulsions, and commercially available alkyd emulsions,
The coating properties were tested.

The results are shown in Table 1.

Test conditions: Drying: 7 days at room temperature (drying property measured by measuring time to dry at room temperature) Membrane thickness: 30 to 40 microns Metal dryer 5 parts of lead acid O, 0.05 part of cobalt naphthenate* were added to Examples 1 and 2, Comparative Examples 2 and 3, and commercially available alkyd emulsions Oxide: cyclohexanone peroxide 40% solution was added to Examples 1 and 2 In Example 3, 0 to 100 parts by weight of resin solid content
．． It was added in an amount of 1 part.

Base material: Untreated steel plate An aqueous copolymer that can be cured at room temperature by introducing an allyl group into a copolymer emulsion obtained by copolymerizing a dicyclopentadiene derivative represented by the above-mentioned formula (1). A combined emulsion can be obtained.

This emulsion has superior hardness, water resistance, corrosion resistance, and solvent resistance compared to conventional thermoplastic acrylic emulsions.

It also has superior drying hardness compared to oxidative curing alkyd emulsions.

Furthermore, it has excellent solvent resistance and corrosion resistance compared to other curable acrylic emulsions.

Claims (1)

[Scope of Claims] 1 (A) 2 to 30 parts by weight of a dicyclopentadiene derivative represented by the general formula (wherein R is hydrogen, lower alkyl, or halogen), (B) α having a hydroxyl group, 3 to 20 parts by weight of β monounsaturated monomer, (C) α copolymerizable with components (A) and (B),
β-unsaturated monomers are blended so that the total of components (A) to 0 is 100 parts by weight, copolymerized, and then (D) obtained by reacting partial allyl ether of polyhydric alcohol with diisocyanate. Partial allyl ether of polyhydric alcohol having terminal incyanate group 2-2
A copolymer emulsion containing copolymer (1) and water (II) obtained by blending and reacting 0 parts by weight.