JPH04164981A - Aqueous resin composition - Google Patents

Abstract

PURPOSE:To improve storage stability, dryness and rust prevention by dispersing a carboxylated alkyd resin (derivative) and a rust preventive pigment in water. CONSTITUTION:Condensation is carried out using 100 pts.wt. (herein-after abbreviated to pts.) mixture comprising 25-60 pts. fatty acid and/or oil (e.g. tung oil), 25-60 pts. epoxy resin, 0-15 pts. 1-18C monobasic acid (e.g. benzoic acid), 0-30 pts. polyol (e.g. polyethylene glycol) with a number-average molecular weight of 400-20,000, and 0-20 pts. polybasic acid (anhydride) (e.g. phthalic acid) to obtain 50-90 pts. (based on solid matter) epoxy ester resin. In the presence of this resin, 50-10 pts. unsaturated alpha,beta-ethylenic monomer (e.g. styrene) is polymerized as required to obtain a carboxylated alkyd resin (A) comprising a (vinyl- modified) epoxy resin and having an acid value of the solid compenent in the resin of 20-50. 100 pts. component A is kneaded with 0.5-10 pts. rust preventive pigment (B), and the hydrophilic groups of the component A are neutralized with an amine. The resultant mixture is dispersed in water while stirring.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a new and useful aqueous resin composition.

More specifically, the present invention relates to an aqueous resin dispersion that has excellent drying properties and excellent corrosion resistance, and is particularly useful as a coating.

[Conventional technology]

Up to now, various antirust paints have been used for the purpose of coating metal materials to prevent rust.

Most of them are oil-based paints, and the large amount of organic solvents they contain are not only undesirable from a work and safety standpoint, but also
In recent years, there has been an increasing demand for switching to water-based paints because they can become a source of environmental pollution.

By the way, this type of water-based paint contains a water-soluble or water-dispersible, so-called water-based resin as a vehicle, but in order to improve the solubility and dispersibility of the resin in water, it is necessary to add They often contain large amounts of carboxyl groups, hydroxyl groups, or ethylene oxide groups, or contain dispersing components such as emulsifiers.

Therefore, the water-retaining properties of water-based resins are high (and combined with the latent heat of vaporization of water, the main solvent, the drying properties of water-based paints are
The fact that water-based paints are slower than oil-based paints is hindering the spread of water-based paints.

In order to improve the drying properties of water-based paints, it is possible to use a large amount of SBR latex, acrylic or acrylic styrene emulsion polymer as a paint vehicle.
Although it is possible to solve the problem, in such a case, the anticorrosion properties of the resulting coating film tend to deteriorate, and in the end, it cannot be said to be preferable.

[Problem to be solved by the invention]

However, as a result of extensive research in order to improve the slow drying properties of conventional water-based paints as described above without impairing the corrosion resistance of the paint film, the present inventors found that Conventionally, an aqueous resin dispersion is obtained by adding a rust preventive pigment to an alkyd resin or a derivative thereof, sufficiently kneading it, and then dispersing it in water using the hydrophilic groups of the alkyd resin or its derivative. The present invention was completed based on the discovery that the resulting coating film exhibits excellent drying properties and also has excellent anticorrosion properties.

That is, the present invention basically includes, as essential components,
Each of them comprises a carboxyl group-containing alkyd resin or its derivative (A) and a rust preventive pigment (B), and can be obtained by dispersing it in water using the hydrophilic groups in the component (A). The present invention aims to provide a specific aqueous resin composition.

In particular, the present invention provides 0.00 parts by weight of the rust preventive pigment (B) per 100 parts by weight of the solid content of the alkyd resin or its derivative (A) having a solid content acid value of 20 to 50. An aqueous resin dispersion containing a rust-preventing pigment, which is obtained by adding 5 to 10 parts by weight to sufficiently cross-wire, and then dispersing it in water using the hydrophilic groups in the component (A), Furthermore, the present invention aims to provide an extremely useful vehicle for water-based paints that has excellent drying properties and anti-corrosion properties.

Here, first of all, as the alkyd resin (A) which is the main constituent component of the aqueous resin composition of the present invention, in particular, as the alkyd resin (A) having a specific acid value, any of the known and commonly used alkyd resins can be used. Although it can be prepared by any method and is not particularly limited, it is preferable to use an epoxy ester resin if the corrosion resistance of the resulting coating film is also taken into account. Considering the hardness W, it is desirable to use a vinyl-modified epoxy ester resin.

Such epoxy ester resins, such as vinyl-modified epoxy ester resins, can be prepared by adding 25 to 60 parts by weight of a fatty acid and/or oil and 25 to 60 parts by weight of an epoxy resin.
parts by weight, 0 to 15 parts by weight of a monobasic acid having 6 to 18 carbon atoms, 0 to 30 parts by weight of a polyol, and further 0 to 20 parts by weight of a polybasic acid and/or its anhydride. A material obtained by condensing selected raw material components in a total amount of 100 parts by weight by a known and conventional method until a desired acid value is reached, that is,
epoxy ester resin, and in the presence of a solid content of 50 to 90 parts by weight of such epoxy ester resin, 50 to 10 parts by weight of α,β-ethylenic insulator for a total of 100 parts by weight. It is a resin obtained by polymerizing saturated monomers by a known and commonly used method, that is, a vinyl-modified evo-cow diester resin.

Moreover, in any of these cases, the solid content acid value of the alkyd resin or its derivative (A) needs to be in the range of 20 to 50.

If the acid value of this material is less than 20, not only will the dispersibility of the resin itself in water be poor, but also it will be difficult to obtain a synergistic effect with the rust-preventing pigment (B) as described below. This is not preferable because the drying properties of the coating film are reduced.On the other hand, if the acid value exceeds 50, the water resistance and corrosion resistance of the coating film will be impaired, which is also not preferable.

Preferably, it has a solid content acid value in the range of 20 to 50, more preferably in the range of 25 to 45.

To exemplify only typical raw materials for the alkyd resin (A), first, tung oil, linseed oil, dehydrated castor oil, safflower oil, soybean oil, castor oil, rice sugar oil, and coconut oil. They are drying oils, semi-drying oils, such as oil or tall oil, and their fatty acids, and it goes without saying that these may be used alone or in combination of two or more types.

Next, to exemplify only particularly typical polyols, ethylene glycol, propylene glycol, and polyols having an average molecular weight (Mn) of 400 to 20,000 are used.
polyethylene glycol or polypropylene glycol, or diethylene glycol, 1,3-butylene glycol, 1゜4-butylene glycol, 2,2
．． 4-1-limethyl-1°3-pentadiol, 1.6
-hexanediol, cyclohexanedimethylol, dimethylolpropionic acid, glycerin, trimethylolethane, trimethylolpropane, tris(2-hydroxyethyl)in cyanurate, pentaerythritol or dipentaerythritol, etc.
Typical examples of polybasic acids include phthalic acid, isophthalic acid, terephthalic acid, tetrahydrophthalic acid, and HYMI.

These include phosphoric acid, maleic acid, fumaric acid, adipic acid, sebacic acid, dimer acid, trimellitic acid or pyromellitic acid, or their acid anhydrides, as well as benzoic acid, p-tert-butyl A C6 to C1g basic acid such as benzoic acid, isooctanoic acid, isodecanoic acid or cyclohexanoic acid can be used in combination.

Furthermore, [Epicron 850, 1050, 3050.
4050 or 7050J C or higher, epoxy resin manufactured by Dainippon Ink & Chemicals ■], [Shrimp: l-t 82
8,834. 1001. 1004゜1007 or 1o09J (epoxy resin manufactured by Shell, Netherlands) or rDER660, 661J, 662,
664J, 667J.

Bisphenol type epoxy resin such as 668 or 669JJ (epoxy resin manufactured by Dow Chemical Co., USA);
Alicyclic epoxy resins such as 9J (epoxy resin manufactured by Union Carbide, USA), phenol borac type epoxy resins such as "Epicron N-740 or 775", "Epifut 812" or "Epolite 40E, 200E" Or 400EJ
Polyethylene glycol-based epoxy resin such as (epoxy resin manufactured by Kyoei Co., Ltd.); or rBF-1000J
By modifying the alkyd resin, various epoxy resins such as epoxy resin such as epoxy resin manufactured by Adeka Argus Chemical Co., Ltd.] can also be used as raw materials for preparing the alkyd resin derivatives. , [Super Veraka Site 10
01 or 3011” [The above are products of Dainippon Ink Chemical Industry ■], ri'-/l, 2181 or 23
Various phenolic resins such as 0ONJ [the above, Hitachi Chemical ■ products] or [Nikalure 0PJ (the above, the above Mitsubishi Gas Chemical ■products); Various petroleum resins such as rTSR165 or YR3168J (terminal hydroxyl group-containing silicone resin manufactured by Toshiba Silicone) or rS F
8427 or 8428J [the above is a terminal hydroxyl group-containing silicone resin manufactured by Toray Silicone ■], r
SF 8421J [epoxy group-containing silicone resin manufactured by Toray Silicone ■] or rSF 8418
J (carboxy-modified silicone resin manufactured by the same company)
In addition to Nato's various silicone resins, we also have nitrocellulose, cellulose acetate butyrate, cellulose acetate propionate, cellulose acetate phthalate, acetylcellulose, cellulose flopionate, cellulose butyrate, methylcellulose, ethylcellulose, butylcellulose, benzylcellulose. ,
Various cellulose derivatives such as carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose or hydroxypropylmethylcellulose can also be used for modification.

Here, assuming the total amount of raw materials to be 100 parts by weight, each
25-60 parts by weight of fatty acids and/or oils, 25-6
0 parts by weight of epoxy resin, 0 to 15 parts by weight of a monobasic acid having 6 to 18 carbon atoms, 0 to 30 parts by weight of polyol,
It is particularly preferable to use the polybasic acid and/or its anhydride in an amount of 0 to 20 parts by weight.

The resin obtained by polymerizing an α,β-ethylenically unsaturated monomer in the presence of the alkyd resin or its derivative (A) as described above and performing a so-called vinyl modification operation. It is particularly desirable to adjust the adhesion, water dispersibility, and hardness of the coating film as appropriate.

At this time, alkyd resin or its derivative (A) and α
, and the β-ethylenically unsaturated monomer, the solid content is suitably within the range of 50:50 to 90:10.

To exemplify only particularly representative α,β-ethylenically unsaturated monomers, those having a carbon number of 1
(meth)acrylic acid esters of alcohols and (meth)acrylic acid; In addition to various glycidyl (meth)acrylates; unsaturated carboxylic acids such as (meth)acrylic acid or itaconic acid; (meth)acrylamides; polyethylene glycol mono(meth)acrylates. ; Hydrophilic monomers containing so-called reactive polar groups, such as polyethylene glycol (meth)acrylates or methoxypolyethylene glycol (meth)acrylates.

In addition, it is of course possible to use water-soluble solvents when modifying or water-dispersing alkyd resins or their derivatives, and only the most representative water-soluble solvents are used. Just to give an example,
ethanol, n-propertool, i-propertool, n
-butanol, i-butanol, 5ec-butanol,
These include alcohols such as tert-butanol or 3-methoxy-3-methylbutanol, various cellosolves, calpitols, and polypropylene glycol monoalkyl ethers.

The aqueous resin composition of the present invention has a solid content of 100% of the thus obtained alkyd resin or its derivative (A), for example.
It is obtained by adding 0.5 to 10 parts by weight of the rust preventive pigment (B) to the parts by weight to mix the mixture, and then dispersing the kneaded product in water. )
As such, known and commonly used ones can be used.

Various chromate compounds such as basic lead chromate, synchromate, strontium chromate or barium chromate; calcium lead, red lead or lead, to mention only the most representative ones. various lead-based compounds such as cyanamide; various phosphate-based compounds such as zinc phosphate, aluminum tripolyphosphate or zinc phosphite; various molybdate-based compounds such as basic zinc molybdate or calcium molybdate; Various balate-based compounds such as barium acid, calcium metaborate or calcium borosilicate; mica-like iron oxide (MI○) or general formula MeO-Fe203---CI) (wherein Me is Ca5Sr, Ba, Mg.

It represents a divalent metal atom such as Zn or Mn. ) various iron oxide compounds such as magnetic ferrite; or various basic tungstate compounds such as zinc tungstate or calcium tungstate; these may be used alone or in combination of two or more. Of course, they may be used in combination.

As mentioned above, the appropriate amount of the rust preventive pigment (B) is within the range of 0.5 to 10 parts by weight, and if it is less than 0.5 parts by weight, the resultant paint will inevitably deteriorate. The drying properties are insufficient, and on the other hand, if it is used in an excessive amount exceeding 10 parts by weight, the effect will be saturated and the storage stability of the resulting aqueous resin dispersion will also be reduced. , both cases are unfavorable.

More preferably, it is used in a range of 1 to 5 parts by weight.

By the way, there is no particular restriction on the method of uniformly dispersing the pigment (B) in the alkyd resin or its derivative (A) as described above, and the anticorrosive pigment may be directly added to the resin (A) and stirred. However, in order to effectively and uniformly disperse the pigment in a short time, it is necessary to add this anticorrosive pigment to a portion of the above-mentioned solvents and resins (A) in advance to uniformly disperse the pigment. A particularly desirable method is to prepare a seed paste, add this to the remaining resin (A), and stir.

Next, the aqueous resin composition of the present invention is prepared by neutralizing the hydrophilic groups, particularly the acid groups, in the resin (A) with amines, and adding water while stirring, to form a so-called aqueous dispersion. Although it is generally obtained by, it is not particularly limited.

In this way, an aqueous resin dispersion containing the alkyd resin or its derivative (A) and the antirust pigment (B) as essential components is obtained.

Although it is possible to use the aqueous resin dispersion as it is as a clear paint, the aqueous resin composition of the present invention has
Furthermore, it can be used in the form of a paint by adding known and commonly used pigments, pigment dispersants, anti-settling agents, thickeners, thixotropic agents, antifoaming agents, dryers, etc.

The pigment weight concentration (PWC) at this time is preferably 60% or less.

If the PWC exceeds 60%, it is undesirable because the rust-preventing ability of the resulting coating film inevitably decreases.

Furthermore, as long as the purpose and characteristics of the present invention are not impaired, aqueous resin compositions containing various water-soluble or water-dispersible resins such as modified amine resins, epoxy resins, polyester resins, or acrylic resins may be used. Of course, it can also be used as a product.

The aqueous resin composition of the present invention has excellent storage stability.
The water-based resin composition of the present invention exhibits excellent drying properties in both cases of drying and heat drying.Thus, by using the water-based resin composition of the present invention, an extremely useful water-based paint having high rust-preventing power can be obtained. .

The mechanism by which these various characteristics are expressed is currently unknown.
Although it is not clear yet, it can be assumed as follows.

First, the storage stability is excellent because the alkyd resin or its derivative (A) and the anticorrosive pigment (B) are kneaded in advance before being dispersed in water. This is probably due to the method of forming a stable mixture in which both of them have good affinity and then dispersing it in water.

Next, the reason why the drying property is excellent is that the carboxyl group in component CA) and the polyvalent metals contained in component (B) form a chelate and gel as water evaporates. it is conceivable that.

〔Example〕

Next, the present invention will be explained by reference examples, examples, and comparative examples.
Layers will be specifically explained, but unless otherwise specified, all parts and percentages are based on weight.

Reference example 1 [Alkyd resin or its derivative (A)
- Preparation example] 400 parts of safflower oil and 180 parts of pentaerythritol were placed in a reaction pot equipped with a stirrer, a thermometer, and a nitrogen gas inlet tube, and lithium hydroxide was added thereto.
The transesterification reaction was carried out for 3 hours at °C. The temperature was then lowered to 180'C, and 310 parts of phthalic anhydride and 110 g of p-tert-butylbenzoic acid were added.
was added and reacted while heating to 210°C,
An alkyd resin having an acid value of 10 was obtained. This (A-1)
It is abbreviated as

Reference Example 2 (same as above) Using the same apparatus as Reference Example 1, 3% of dehydrated castor oil fatty acid was prepared.
Using 50 parts of Ebicuron 1050J (bisphenol A type epoxy resin manufactured by the previous company) and 100 parts of Ebicuron 4050J (same as above), a condensation reaction was carried out at 220°C until the acid value reached 10. The temperature was lowered to 180°C, 100 parts of phthalic anhydride and 150 parts of neopentyl glycol were added, and the mixture was reacted at 220°C to obtain an epoxy ester resin with an acid value of 20. This was called (A-2). Abbreviated.

Reference Example 3 (same as above) Using the same apparatus as Reference Example 1, 350% of linseed oil fatty acid
A condensation reaction was carried out using 580 parts of Ebicuron 1050J and 580 parts of Ebicuron 1050J until the acid value reached 5, and then 18
The temperature was lowered to 0° C., 50 parts of trimellitic anhydride and 20 parts of maleic anhydride were added, and the mixture was reacted until the acid value reached 35 to obtain an epoxy ester resin. This (A
-3).

Reference Examples 4 to 8 (same as above) Alkyd resin (A-1) obtained in Reference Examples 1 and 2
And by vinyl-modifying the epoxy ester resin (A-2) under the conditions shown in Table 1,
Various vinyl-modified epoxy ester resins (A-4) to (A-8) were obtained.

Examples 1 to 7 and Comparative Examples 1 to 6 Antirust pigments and the like were added to each of the alkyd resins and their derivatives obtained in Reference Examples 3 to 8 at the blending ratios shown in Table 2. Various aqueous resin compositions were obtained.

At this time, the carboxyl groups in the alkyd resin or its derivatives are completely neutralized with triethylamine, and then
A method of adding a rust preventive pigment and kneading it in a sand mill, and then dispersing it in water to obtain an aqueous resin with a solid content of 40% (dispersion method I), or for comparison, an alkyd resin or its The carboxyl group in the derivative is completely neutralized with triethylamine, then it is dispersed in water, and then a rust preventive pigment is added to the resulting aqueous resin dispersion, and the mixture is mixed in a sand mill (dispersion method ■). Using.

Furthermore, for comparison purposes, the addition of anti-rust pigments was
An aqueous resin dispersion of the missing form was also prepared.

The stability evaluation results for each aqueous resin dispersion are summarized in Table 2.

Application Examples 1 to 7 and Comparative Application Examples 1 to 6 Various water-based paints were prepared according to the following black paint formulation (1) and reddish brown paint formulation (2).

Next, each paint was applied to an untreated dull steel plate degreased with toluene so that the dry film thickness was 2 microns in 20 parts, and dried at 23°C for 7 days to obtain a cured film.

A comparative study of various physical properties was conducted for each cured coating film. The results are summarized in Table 3.

In addition, using the same steel plate, 20 parts of each paint was applied on the steel plate at room temperature of 23°C, and on the other hand on the steel plate preheated to 90°C, so that the dry film thickness was 2 microns. The dry-to-touch time at room temperature and the dry-to-touch time under preheating are also described in the same table.

Paint formulation (1) Water-based resin (solid content 40%) 100 parts "Disperse Black" 3// [Carbon dispersed pigment manufactured by Dainippon Ink and Chemicals Co., Ltd.] "Dicknate 3111J 1.0 = [
Cobalt naphthenate dispersion manufactured by Dainippon Ink & Chemicals Co., Ltd.] Paint solid content = 38-40% Pigment concentration (PWC) = 3% * Appropriate amount of paint formulation to adjust paint viscosity to 400 ± 200 centivoise (2) Water-based resin (solid content 40%) 100 parts rloOE
DJ 20 = [Red iron made by Toda Kogyo Co., Ltd.] rNS-200J 20/l [Lucium carbonate made by Nitto Funka Co., Ltd.] "Dicknate 3111J 1. O/l paint solid content = 50 to 53% Pigment concentration (PWC) = 50% * Appropriate amount to adjust the paint viscosity to 700 ± 300 centipoise [Effects of the invention j As is clear from the above results, the aqueous resin composition of the present invention has good storage stability. Furthermore, the composition of the present invention has good drying properties both when drying at room temperature and when drying by heating.

Therefore, it can be said that the aqueous resin composition of the present invention can provide an extremely useful aqueous paint having high antirust properties.

Claims (1)

[Claims] 1. A kneaded product of a carboxyl group-containing alkyd resin or its derivative (A) and a rust preventive pigment (B) is dispersed in water using the hydrophilic groups in the component (A). An aqueous resin composition obtained at least. 2. Add 0.5 to 10 parts by weight of the rust preventive pigment (B) to 100 parts by weight of the alkyd resin or its derivative (A) having a solid content acid value of 20 to 50 and thoroughly knead. An aqueous resin composition obtained by dispersing the alkyd resin or its derivative (A) in water using the hydrophilic groups in the alkyd resin or its derivative (A). 3. The above alkyd resin (A) contains 25 to 60 parts by weight of fatty acid and/or oil, and 25 to 60 parts by weight of epoxy resin.
Parts by weight, 0 to 15 parts by weight of a monobasic acid having 6 to 18 carbon atoms, 0 to 30 parts by weight of a polyol, and 0 to 20 parts by weight of a polybasic acid and/or its anhydride, totaling 100 parts by weight. The aqueous resin composition according to claim 1 or 2, which is an epoxy ester resin obtained by condensing. 4. The above alkyd resin or its (A) contains 25 to 60 parts by weight of fatty acid and/or oil, 25 to 60 parts by weight of epoxy resin, and 0% of monobasic acid having 6 to 18 carbon atoms.
The solid content of the epoxy ester resin obtained by condensing a total of 100 parts by weight consisting of ~15 parts by weight, 0 to 30 parts by weight of polyol, and 0 to 20 parts by weight of polybasic acid and/or its anhydride, is 50 parts by weight. The aqueous resin according to claim 1 or 2, which is a vinyl-modified epoxy ester resin obtained by polymerizing 50 to 10 parts by weight of an α,β-ethylenically unsaturated monomer in the presence of 90 parts by weight. Composition.