JPS5910726B2 - Method for producing water-dilutable self-curing resin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a water-dilutable self-curing resin, which resin is useful as a water-dilutable coating resin.

Conventionally, as disclosed in U.S. Pat. No. 2,604,464, U.S. Pat. Thermosetting paints that are simply physically mixed in a greenhouse are known.

However, this type of paint requires a high temperature and a long time to be thermally cured, and if curing is insufficient, the alkali resistance and acid resistance are poor, and therefore a reaction accelerator is often used.

However, it is generally known that the combined use of a catalyst is not preferable because it deteriorates the performance of the paint, and that it impairs water resistance and weather resistance.

In addition, since the resins are simply mixed physically, the compatibility of the resins becomes a problem, especially when using high molecular weight epoxy resins, such as Epicoat 1 commercially available from Shell Chemical Company.
001, Epicoat 1004, etc., there are limits to their compatibility and they cannot be used at all, or there are restrictions on the type and amount of vinyl monomer in order to obtain compatibility.
This has been a major obstacle in producing useful paints. The above also applies to water-soluble, thermosetting coatings obtained by neutralizing the above-mentioned copolymers with amines.

The present invention solves these problems.

In the present invention, in the presence of 5 to 30% by weight of an adduct of a polyoxide and an unsaturated dicarboxylic acid, (a) 8 to 15% by weight of an α,β monounsaturated monocarboxylic acid, (b) an α,β monounsaturated 1 to 8% by weight of a monocarboxylic acid amide, a methylolated product thereof, or an alkyl etherified product of the methylolated product, and (c) 86 to 47% by weight of other copolymerizable unsaturated monomers.
The present invention relates to a method for producing a water-dilutable self-curing resin, which comprises polymerizing and neutralizing a water-dilutable self-curing resin.

This resin is a graft type polymer compound having an epoxy group, a carboxyl group, a hydroxyl group, a methylol group, or an alkyl ether group as a functional group.

This resin is stable at room temperature and rapidly thermosets when heated, and is a coating material made by mixing the previously known copolymer containing α,β monounsaturated monocarboxylic acid and epoxy resin. It cures at a lower temperature, is harder and tougher under the same curing conditions, and provides coatings with better adhesion, flexibility, chemical resistance, stain resistance, and hot water resistance. . Furthermore, since the polyepoxide is chemically bonded to the linear polymer, that is, the epoxy resin is contained as a component of the resin, so there is no problem with compatibility.

The polyepoxide to which the unsaturated dicarboxylic acid is added is a compound having two or more epoxy groups in the molecule, one or more hydroxyl group in the molecule, and having an epoxy equivalent of 425 to 4,000. Preferably.

In particular, polyether type diepoxides derived from polyhydric phenols or polyhydric alcohols having an epoxy equivalent of 875 to 1,025 are preferred. If an epoxide with an epoxy equivalent of less than 425 is used, flexibility, corrosion resistance, and adhesion will be poor, and if the epoxy equivalent is more than 4,000, workability, water solubility, and stability will deteriorate, making it impractical. There is a tendency to chip.

Suitable polyepoxides include condensation products of bisphenol A and epichlorohydrin, such as Ciel.
Epicoat 1001, Epicoat 100 manufactured by Chemical Co., Ltd.
4, Epicort 1007, Epicort 1009, Ciba Araldite 6071, Araldite 6084
．． , Araldite 6097,. Examples include Araldite 6099, condensation products of ethylene glycol and epichlorohydrin, and condensation products of glycerin and epichlorohydrin. Examples of the unsaturated dicarboxylic acids include maleic acid, fumaric acid, itaconic acid, etc. Among these, those in which acid anhydrides exist may be used in this form.

The adduct of polyepoxide and unsaturated dicarboxylic acid is an adduct obtained by reacting the epoxy group of polyepoxide with the carboxyl group of unsaturated dicarboxylic acid. It is preferable to use the ratio such that the ratio is /1 to 2/2 (equivalent ratio).

The amount of the additive used is 5 to 30% by weight.

If it is less than 5% by weight, the heat curing reaction at low temperatures will slow down, which is undesirable, and if it exceeds 30% by weight, it will not only impair the stability of the paint but also the weather resistance of the coating film, and when used as white enamel. The initial yellowing is significant, making it undesirable for paints that require high weather resistance and whiteness, such as paints for automobiles and paints for home appliances.

Examples of the α,β monounsaturated monocarboxylic acid [component (a)] include acrylic acid, methacrylic acid, crotonic acid, etc., α,β monounsaturated monocarboxylic acid amide, α
, methylolated product of β-unsaturated monocarboxylic acid amide or its alkyl etherified product [component (b)] includes acrylamide, methacrylamide, N-methylolacrylamide, N-methylolmethacrylamide, N-methylolmethacrylamide,
-n-butoxymethylacrylamide, N-n-butoxymethylmethacrylamide, isobutoxymethylacrylamide, isobutoxymethylmethacrylamide, and the like.

The above component (a) is used in an amount of 8 to 15% by weight.

If it is less than 8% by weight, water solubilization becomes difficult, and if it exceeds 15% by weight, water resistance and chemical resistance decrease, which is not preferable.

The above component (b) is used in an amount of 1 to 8% by weight.

If it is less than 1% by weight, thermosetting properties will be poor, and if it exceeds 8% by weight, water resistance and hot water resistance will be poor, which is not preferred.

Moreover, two or more types of component (b) may be used in combination.
Examples of unsaturated monomers [component (c)] copolymerizable with the above components (a) and (b) include hydroxy acrylate such as β-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, and hydroxybutyl acrylate. alkyl,
Similar hydroxyalkyl methacrylates, ethyl acrylates, butyl acrylates, alkyl acrylates having a C1-12 alkyl group such as 2-ethylhexyl acrylates, similar alkyl methacrylates, styrene, vinyltoluene, α-methylstyrene styrene derivatives such as
Examples include unsaturated nitriles such as acrylonitrile and methacrylonitrile, vinyl acetate, and vinyl chloride, which may be used alone or in combination of two or more. The amount of component (c) used is such that the total amount of the additives (a) component, (b) component and (c) component is 100% by weight. That is, 86-47% by weight is used. If it is less than 47% by weight, flexibility, adhesion, water resistance, and weather resistance will be poor, and if it is 86% by weight.
If it exceeds this value, the solvent resistance, alkali resistance, and corrosion resistance of the coating film will be insufficient, and it will lack practicality.

Among component (c), the unsaturated monomer having a hydroxyl group is preferably used in an amount of 10% by weight or less in component (c). In the present invention, polymerization can be carried out by solution polymerization using a polymerization catalyst at a temperature of about 80 to 120°C.

Examples of the polymerization catalyst include organic peroxides such as benzoyl peroxide, di-t-butyl peroxide, and cumene peroxide, and azobis-based compounds such as α-α5-azobisisobutyronitrile.

In addition, as a solvent used for solution polymerization, butyl cellosolve,
Examples include ethyl cellosolve, butanol, isobutanol, cellosolve acetate, and isopropanol. The resins obtained in this way can contain ammonium, triethylamine, monoethanolamine, diethanolamine,
Neutralized with amines such as triethanolamine and dimethylaminoethanol, and basic substances such as alkali metal hydroxides.

Neutralization may be carried out sufficiently to impart water dilutability, preferably with a basic substance in an amount approximately equivalent to the carboxyl group. The neutralization step can be performed subsequent to the solution polymerization reaction. In this case, a water-diluted coating composition can be obtained by subsequently adding water. The water-dilutable self-curing resin obtained according to the present invention is made into a coating composition using a water-soluble organic solvent and water as a solvent.
Preferably, it is expressed as % by weight.

This coating composition may further contain pigments such as titanium dioxide and carbon black, fillers such as calcium carbonate, known stabilizers, and the like as appropriate. Furthermore, a methylated melamine resin such as hexamethoxymethylmelamine may be added as a curing agent. Next, examples of the present invention will be shown. Example 1 Into a flask equipped with a stirrer, a thermometer, a reflux condenser, a dropping load, and a gas introduction tube, 300 parts by weight of an epoxy resin (Epicote 1004, trade name of Ciel Chemical Co., Ltd.),
20 parts by weight of maleic anhydride and 21 parts by weight of butyl cellosolve
3 parts by weight were charged and reacted at 130° C. for about 4 hours until the acid value reached 14 to produce an adduct.

The obtained reaction solution had a heating residue of 60.5% by weight and a viscosity of Y-
Z (25°C, Cardner). In a flask similar to the above, 25 parts by weight of the above reaction solution and 100 parts by weight of butyl cellosolve were charged and the temperature was raised to 140°C, followed by 15 parts by weight of methyl methacrylate, 55 parts by weight of ethyl acrylate, and 6 parts by weight of N-n-butoxymethylacrylamide. A mixture of 9 parts by weight of methacrylic acid, 1 part by weight of ditertiary butyronitrile, and 1 part by weight of azobisisobutyronitrile was added dropwise over 2 hours, and then kept at 140° C. for 6 hours.

Thereafter, the mixture was cooled to 60 to 70°C, 8 parts by weight of triethylamine was added, and the mixture was kept warm for about 1 hour to produce a resin according to the present invention. The properties of the obtained resin solution were as follows: heating residue: 50.1% by weight, viscosity (25°C, cardner): U-, and pH: 7.9. Examples 2 to 6 Example 1 was conducted using the formulations shown in Table 1.

Table 1 shows the properties of the resin solutions obtained in Examples 1 to 6.
Application examples 1 to 6 50 parts by weight of the resin solution obtained in Examples 1 to 6 and titanium white 40
After kneading the weight part three times with three rolls, butyl cellosolve/
A mixed solution of water = 1/9 (weight ratio) was added, and the mixture was adjusted to about 80 seconds at a food cup +4 (25°C).

O Comparative Example 1 in which the properties of the coating film of the water-diluted self-curing coating composition thus obtained were tested. An attempt was made to mix the resulting resin solution with an epoxy resin (Epicoat 1004, trade name of Ciel Chemical Co., Ltd.) and make it into a paint, but the above resin (copolymer) and epoxy resin were not compatible and it was used as a paint. I couldn't do it.

Comparative Example 2 As a combination of oil-less alkyd resin/butylated melamine resin, Phthalkit SPXlO3/
Melan 28 (In both cases, the solvent is an organic solvent.

) to prepare a mixture of 85/15 (solid content weight ratio).
The film properties of this coating composition were tested. Comparative Example 3 The coating film properties were tested using a vinylated alkyd resin solution (Hytaloid 9005, solvent: organic solvent).

Comparative Example 4 Self-curing acrylic resin solution (Hytaloid 2
605, Solvent: Organic solvent, does not contain the above adduct as a resin component.

) was used to test the coating film properties. Note that Phthalkit SPXlO3, Melamine 28, Hitaloid 9005, and Hitaloid 2605 are all trade names of Hitachi Chemical Co., Ltd.

Table 2 shows the coating film properties of Application Examples 1 to 6 and Comparative Examples 2 to 4. The water-dilutable, self-curing resins obtained by the present invention are useful in water-dilutable coating compositions and have performance equivalent to or better than conventional organic solvent-based paints.

Claims (1)

[Claims] 1. Adduct of polyepoxide and unsaturated dicarboxylic acid 5
In the presence of ~30% by weight, (a) 8 to 15% by weight of an α,β-unsaturated monocarboxylic acid, (b) an α,β-unsaturated monocarboxylic acid amide, a methylolated product thereof, or a methylolated product thereof. 1 to 8% by weight of alkyl etherified product, and (c) 86 to 47% by weight of other copolymerizable unsaturated monomers.
A method for producing a water-dilutable self-curing resin, which comprises polymerizing and neutralizing a water-dilutable self-curing resin.