JPS62232469A - Resin composition for use in dispersion of rust-resisting pigment - Google Patents

Abstract

PURPOSE:To provide the titled resin compsn. having excellent storage stability and an excellent effect of dispersing a rust-resisting pigment, by reacting an org. compd. having a carboxyl group and contg. bivalent sulfur exhibiting no acidity with a specified polyol compd. CONSTITUTION:An org. compd. (A) having at least one carboxyl group and contg. bivalent sulfur which is not acidic (e.g., 2-thiophene-acetic acid) is reacted with a polyol compd. (B) selected from the group consisting of polyether polyols, polyester polyols and polyether polyester polyols. The reaction product is used as the main component to obtain the desired resin compsn. for use in dispersing rust-resisting pigments. Examples of the component B are compds. of the formula (wherein R is a residue obtd. by removing hydroxyl groups from a polyhydroxy compd.; R<1> is H or methyl; l+m is not smaller than 1; and n is not smaller than 3).

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a resin composition for dispersing rust preventive pigments and a rust preventive pigment dispersion paste which has good dispersibility of rust preventive pigments and has excellent storage stability. be.

Conventional technology Primers applied to steel structures, etc. usually contain anti-rust pigments, but in order to disperse the anti-rust pigments, a portion of the resin vehicle, which is the main component of the anti-rust paints, is taken and the pigments are dispersed. A paste was first made and mixed with the remaining resin vehicle, and no special resin for the anticorrosive pigment dispersion paste was used. Moreover, storage stability is always an issue with these pigment dispersion pastes. For example, in the case of strontium chromate, a typical anti-corrosion pigment, the chromate precipitates, and the precipitated pigment remains even after storage for a relatively short period of time. The pigment often aggregates to form a hard cake, and to prevent this, it is necessary to add an anti-settling agent for the pigment. Furthermore, in the case of anti-corrosion pigments, it is relatively difficult to disperse them into resin, so even if steel beads are used, a long dispersion treatment of over two hours is required, and it is extremely difficult to atomize the pigment. I was forced to use it without using it.

Problems to be Solved by the Invention Therefore, a rust preventive pigment made of heavy metals or heavy metal compounds can be atomized in a short time, has excellent pigment dispersibility, has high storage stability when made into a pigment dispersion paste, and is suitable for primer use. There is a demand for a resin composition for dispersing rust-preventing pigments that is compatible with resins, and the present invention [1]
It is true.

Means for Solving the Problems According to the present invention, the above-mentioned object has at least one carboxyl group and acidity in the molecule t':.

This can be achieved using a resin composition obtained by reacting an organic compound containing valent sulfur with a polyol compound.

The organic compound containing divalent sulfur constituting the resin composition according to the present invention is characterized in that it has at least one carboxyl group in its molecule, and the divalent sulfur does not exhibit acidity. It is. Therefore, as the bond of the sulfur atom, only the -S- bond excluding the -8-H bond is intended, and this -8- bond may be present in a chain compound or a cyclic compound.

Any organic compound can be used as long as it has such divalent sulfur and carboxyl group, but typical examples are as follows.

Cyclic compounds: (A) Thiophene compounds, such as 2-thiophene-acetic acid, 2-thiophenecarboxylic acid, etc. (B) Thiazole compounds, such as (2-amino-4-thiazolyl)-acetic acid, etc. = 3- (C) Other heterocycles Formula compounds such as biotin, L-thioproline, 6-aminopenicillanic acid, 7-amitucephalosboranic acid, 7-amitudesacetoxycephalosboranic acid, etc. Chain compounds: Compounds containing (D)-8-bonds For example, thiodiglycolic acid, thiodipropionic acid, thiodisuccinic acid, methylenebisthioglycolic acid, thioglycolic acid, phenylthioglycolic acid, 2,5-dichlorophenylthioglycolic acid, thenoic acid, 3-methylthiopropionic acid, etc. (E)- Compounds containing 8-1N, such as S-(carboxymethyl)-L-cysteine,
Compounds containing (F)-8-8-bonds such as N-acetyl-8-benzyl-D-cysteine, such as 3,3'-dithiodipropionic acid, α-riboic acid, 5,5'-dithio-bis(2 -nitrobenzoic acid), 2,2'-dithiodibenzoic acid, etc. These are only specific examples of commercially available compounds, and do not limit the present invention.

Another component of the resin according to the invention is a polyol compound. Such polyols are usually used as paint resins, and include, for example, oil-free polyester polyols, long-oil alkyd polyols, short-oil alkyd polyols, acrylic polyols, polyether polyols, and polyether polyester polyols.
Particularly suitable for pigment pulverization are polyols with low viscosity, such as polyester polyols, polyether polyols, polyether polyester polyols, especially those having a number average molecular weight of 10.
000 or less is preferable. Furthermore, as a low viscosity product, Japanese Patent Application Laid-Open No. 59-12492, which was invented by the same applicant,
2 specification, JP-A-60-115624, JP-A-60-137924, JP-A-60-1379
Polyether polyols, polyester polyols, polyether polyester polyols, etc. having a star structure described in No. 67 and the like are preferably used. For example, the formula RC(OCHzGHR')Q-(OOC(CHz)
i;) ll1oHE n (in the formula, R is a residue obtained by removing a hydroxyl group from a polyhydroxy compound, R' is a hydrogen atom or a methyl group, Ω and m are each O or a positive integer, but Q + m is at least 1) , n is an integer of 3 or more) is an example of the most preferably used polyol compound.

The reaction between the polyol compound and the organic compound containing carboxyl groups and non-acidic divalent sulfur is carried out by a condensation reaction method of carboxyl groups and hydroxyl groups that is commonly used in the production of polyesters for paints.

That is, both raw materials may be reacted by heating in the presence of a suitable catalyst such as dibutyltin oxide.

The present inventors have discovered that the resin containing divalent sulfur, which does not show acidity, obtained in this way is a heavy metal or a heavy metal oxide.
It adsorbs these substances through interaction with salts, etc., and is therefore effective as a dispersant for rust preventive pigments made of heavy metal compounds.The rust preventive pigments can be pulverized in a short time, and the pigment dispersion paste is stable in storage. The unexpected effect of this method was that it had extremely good properties and was unlikely to cause pigment sedimentation or hard cake formation.

The reason why -8-H bonds are excluded from divalent sulfur in the present invention is because the SH groups remaining in the resin are acidic, which causes problems in water resistance, especially boiling water resistance, when formed into a coating film. This is due to the following reasons.

Since the resin according to the present invention contains a reactive hydroxyl group, acidic groups and/or basic groups can be appropriately introduced as desired, and modification such as urethanization can also be carried out freely.

The rust-preventing pigment dispersion paste may be prepared by uniformly dispersing only the above-mentioned dispersing resin according to the present invention and the rust-preventing pigment made of a heavy metal or a heavy metal compound, but usually a solvent is added to form a dispersion paste.

Such solvents include, for example, hydrocarbon solvents (e.g. toluene, xylene, Tsurpez 100, Tsurpez 150).
), ester solvents (e.g. ethyl acetate, butyl acetate)
, alcoholic solvents (for example, methyl ethyl ketone, methyl isobutyl ketone), and the like. In addition, when dispersing and mixing, use normal dispersion and mixing methods such as roll mills, ball mills, sand mills, and planetary mills. A dispersing machine such as a no-mixer or a high-speed disperser is used. As appropriate, the dispersion paste may contain
A resin, a modifier, a curing agent, etc. may be added.

The ratio of the dispersing resin to the antirust pigment can be appropriately selected from a wide range, but preferably the ratio of resin solid content to pigment is 5:95.
~80: Selected within the range of 20.

The pigment dispersion paste prepared as described above can be stored stably and has excellent compatibility with other resins. It can be mixed uniformly with ether resin etc. to prepare a coating composition. It has also been found that epoxy resins and modified epoxy resins are particularly preferred as such resin vehicles.

The present invention will be explained below with reference to Examples. Parts and percentages are by weight unless otherwise specified.

Example 1 Synthesis of dispersion resin 142 parts of thiophene acetic acid and 6.2 parts of dibutyltin oxide as a catalyst were added to 3000 parts of polyester polyol (Plaxel 230AL, manufactured by Daicel Chemical Co., Ltd., molecular weight 3000, number of functional groups 2), and heated to 200°C. and react until the acid value reaches 0.5. After cooling, 1033 parts of xylene are added. This resin is designated as A.

Separately, 222 parts of isophorone diisocyanate is dissolved in 222 parts of cellosolve acetate, heated to 80° C., and then a solution of 113 parts of C-caprolactam and 113 parts of cellosolve acetate is added dropwise over 1 hour to react. After the dropwise addition was completed, the reaction was completed while keeping the temperature at 80°C for another 3 hours, and the isocyanate equivalent was 680g.
An equivalent amount of product B is obtained.

Add 560 parts of resin B to 4157 parts of resin A, complete one reaction while keeping the temperature at 90°C, and then add 146 parts of isobutanol to obtain dispersion resin C. The molecular weight of Resin C was 5,200.

Preparation of coating composition (a) Epoxy resin Epotote YD-014 (manufactured by Tobu Kasei Co., Ltd.) 28 parts as non-volatile content (b) Thiophene acetic acid modified urethanized polycaprolactone (resin C) 7 parts as non-volatile content (c) Strontium chromate pigment 40 parts (d) Zinc phosphate pigment 10 parts (e) Cyclohexanone (solvent for adjusting viscosity) (b) Resin solvent, (c)
(d) Add (e) and glass peas, disperse using a sand mill, and add the resin solution of (,) to obtain a coating composition.

Example 2 Synthesis of dispersing resin 120 parts of 3-methylthiopropionic acid and 6.2 parts of dibutyltin oxide were added to 3000 parts of a tetrafunctional polyester polyol (molecular weight 3000) synthesized with E-caprolactone as the main component. Heat to ℃,
React until the acid value reaches 1.0. After cooling, xylene 1020
Add part.

This resin is designated as D.

Separately, 222 parts of isophorone diisocyanate is dissolved in 222 parts of cellosolve acetate, heated to 80°C, and then a solution of 113 parts of ε-caprolactam and 113 parts of cellosolve acetate is added dropwise over 1 hour to react. After the dropwise addition, the reaction was completed while keeping the temperature at 80°C for another 3 hours, and the isocyanate equivalent was 670g.
An equivalent amount of product E is obtained.

700 parts of resin E is added to 122 parts of resin 04, the reaction is completed while keeping the temperature at 90°C, and 488 parts of isobutanol is added to obtain 1 dispersion resin F. The molecular weight of resin F is 67
It was 00.

Preparation of coating composition (a) Z poxy resin Evo I Hate YD-014 (manufactured by Tobu Kasei Co., Ltd.) 28 parts as non-volatile component (b) 3-Methylthiopropionic acid modified urethanized polycaprolactone (resin F) Non-volatile 7 parts (C) Strontium chromate pigment 40 parts (d) Zinc phosphate pigment 10 parts (e) Cyclohexanone (solvent for adjusting viscosity) (b) in a resin solution of (c)
(d) Add (e) and glass peas, disperse using a sand mill, and add the resin solution of (a) to obtain a coating composition.

Example 3 Synthesis of dispersion resin Star type polyether polyol (molecular weight 2000) 2
000 parts, 154 parts of 2-amino-4-thiazolyl acetic acid and 6.2 parts of dibutyltin oxide were added, and the mixture was heated at 200°C.
and react until the acid value reaches 0.8. After cooling, 710 parts of xylene are added. This resin is designated as G.

Add 8700 parts of resin to 02846 parts of resin, complete the reaction while keeping the temperature at 90°C, and add 31u parts of isobutanol to obtain resin H. The molecular weight of Resin H was 6,100.

Preparation of coating composition (a) Epoxy resin Evotote YD-014 (manufactured by Tobu Kasei Co., Ltd.) 28 parts as non-volatile content (b) 2-Amino-4-thiazolyl acetic acid modified urethanized polyether polyol (Resin H) as non-volatile content
7 parts (C) Strontium chromate pigment 40 parts (d) Zinc phosphate pigment 10 parts (e) Cyclohexanone (viscosity adjusting solvent) Into the resin solution of (b), (c)
) (d) (e) and glass peas are added, dispersed using a sand mill, and the resin solution of (a) is added to obtain a coating composition.

Preparation of Comparative Example Paint Composition (a) Epoxy resin Evotote YD-014 (manufactured by Tobu Kasei Co., Ltd.) 35 parts as non-volatile content (c) Strontium chromate pigment 40 parts (d) Zinc phosphate pigment 10 parts (e) Cyclohexanone (viscosity Adjustment solvent) Add (c), (d), (e) and glass beads to a resin solution containing 7 parts as a non-volatile component of (a), disperse using a sand mill, and add 7 parts as a non-volatile component of (a). A coating composition is obtained by adding a resin solution containing 28 parts.

Using the above coating composition, the following tests were conducted to evaluate the performance, and the results are shown in the table.

Test Method Dispersibility The particle size was determined using a grind gauge after 30 minutes, 60 minutes, and 90 minutes after the start of dispersion.

Storage stability Cake (sediment) formed after paint preparation
Judging the condition by hardness and volume.

Hardness 0...Soft Δ...Hard (redispersible)
×...Hard (redispersion not possible) Amount 0...None Δ...Small amount ×...Large amount (hereinafter referred to as margin) Patent application agent

Claims (3)

[Claims] (1) A protective compound obtained by reacting an organic compound containing at least one carboxyl group and non-acidic divalent sulfur in the molecule with a polyol compound selected from the group consisting of polyether polyol, polyester polyol, and polyether polyester polyol. Resin composition for dispersing rust pigments. (2) The polyol compound has the formula, R[(OCH_2CHR')l-(OOC(CH_2)
_5) mOH]n (in the formula, R is a residue obtained by removing the hydroxyl group from a polyhydroxy compound, R' is a hydrogen atom or a methyl group, l and m are each 0 or a positive integer, but l
+m is at least 1, and n is an integer of 3 or more. (3) A pigment obtained by reacting an organic compound containing at least one carboxyl group and non-acidic divalent sulfur in the molecule with a polyol compound selected from the group consisting of polyether polyol, polyester polyol, and polyether polyester polyol. A rust-preventing pigment dispersion paste comprising a dispersing resin composition and a rust-preventing pigment made of a heavy metal or a heavy metal compound.