JPH04189819A - Resin for dispersing pigment - Google Patents

Abstract

PURPOSE:To obtain the subject resin, consisting of an amidemodified polyester resin prepared by subjecting a polybasic acid, a polyhydric alcohol and a hydroxyl group-containing organic acid amide as essential components to condensing reaction, sufficiently compatible with various resins for coatings and having a specific hydroxyl value and a specified number-average molecular weight. CONSTITUTION:The objective resin is composed of an amide-modified polyester resin prepared by subjecting a polybasic acid (preferably hexahydrophthalic anhydride), a polyhydric alcohol (e.g. ethylene glycol) and an OH group- containing organic acid amide expressed by the formula (R is 1-18C aliphatic hydrocarbon group; R<1> is 1-8C hydroxyalkyl; R<2> is H, 1-18C hydroxyalkyl, 1-18C alkyl or 2-18C dihydroxyalkyl) (used in an amount of 0.5-7.0wt.% based on the whole raw materials) to condensing reaction. The aforementioned amide- modified polyester resin has 40-240 OH value and 700-2000 number-average molecular weight.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a resin for dispersing pigments that has excellent pigment dispersibility and is well compatible with various resins for paints.

[Conventional technology]

Currently, there are many types of resins used as paint bases depending on the purpose. For example, if appearance is important,
Acrylic resins, alkyd resins, etc. are used, and each of them can be baked into a mold or dry at room temperature. Depending on the purpose, baking can be done using mold acrylic paint or resins with different properties may be used.

In addition, epoxy resins, vinyl resins, and other resins are also used.

When color matching is performed using paints, the usual method is to mix a plurality of primary color paints based on the same resin. If paints made of different resins are mixed together, the compatibility of the resins may not be good.
In that case, the gloss of the snow surface will be reduced, and the physical and chemical properties inherent in the paint will be impaired to some extent.

Therefore, several types of primary color paints are required for one resin-based paint, and similarly, several types of primary color paints are required for each other resin-based paint, so there are a huge number of types of primary color paints. This is unfavorable in terms of production efficiency and also causes problems in production control.

On the other hand, primary color paints are made by using low-molecular resins that are compatible with a relatively wide range of resins, such as urea-based, triazine-based, polyglycol-based, and acrylic-based resins, and in which pigments are dispersed. It is considered that the above-mentioned problems in terms of production efficiency can be avoided by preparing the same.

However, such low-molecular resins have the disadvantage that when mixed with various resins for paints, the physical properties and durability of the coating film generally deteriorate.

[Problems to be Solved by the Invention] As described above, in the past, almost no resin for pigment dispersion has been found that is compatible with various resins for paints and can exhibit good coating film properties. There was no such thing, and its appearance was strongly desired.

In view of the above-mentioned conventional circumstances, the present invention has excellent pigment dispersibility, and is well compatible with resins for various paints such as alkyd, acrylic, vinyl, and epoxy paints, and can be mixed with these resins. The object of the present invention is to provide a resin for pigment dispersion that can maintain good coating film properties without impairing the inherent performance of each resin.

[Means for Solving the Problems] As a result of intensive studies to achieve the above object, the present inventors have found that, in addition to polybasic acids and polyhydric alcohols, they can be solved by using a specific organic acid amide containing a hydroxyl group. The present inventors have discovered that an amide-modified polyester resin obtained by subjecting components to a condensation reaction is well compatible with a wide range of resins and exhibits good pigment dispersibility, leading to the completion of the present invention.

That is, the present invention provides, in addition to polybasic acids and polyhydric alcohols, the following general formula (a); RC〇-N-R2・ia
+ (wherein, R is an aliphatic hydrocarbon group having 1 to 18 carbon atoms, R1
is a hydroxyalkyl group having 1 to 18 carbon atoms, and R2 is selected from a hydrogen atom, a hydroxoalkyl group having 1 to 18 carbon atoms, an alkyl group having 1 to 18 carbon atoms, and a dihydroxyalkyl group having 2 to 18 carbon atoms. A hydroxyl group-containing organic acid amide represented by the following formula is an essential component, and the proportion of the above organic acid amide is 0.5 to 7.
It consists of an amide-modified polyester resin obtained by condensation reaction of 0% by weight polyester raw material, and has a hydroxyl value of 40 to 240 and a number average molecular weight of 700 to 2,000.
This invention relates to a resin for pigment dispersion characterized by the following.

[Structure and operation of the invention]

In the present invention, polybasic acids used as one of the essential components of the polyester raw material include hexahydrophthalic anhydride, phthalic anhydride, isophthalic acid, tetrahydrophthalic anhydride, trimellitic anhydride, adipic acid, sehasonic acid, and maleic anhydride. There are various polybasic acids that are commonly used for producing polyester, and one or more of these can be used. Among these, it is particularly preferable to use hexahydrophthalic anhydride in terms of physical properties, weather resistance, compatibility, and the like.

In addition, polyhydric alcohols used as one of the essential components of polyester raw materials include ethylene glycol,
In addition to dihydric alcohols such as propylene glycol, diethylene glycol, polypropylene glycol, neopentyl glycol, and hexylene glycol, glycerin, trimethylolethane, trimethylolpropane,
Examples include pentaerythritol, and one or more of these may be used.

In the present invention, in addition to using the polybasic acid and polyhydric alcohol as essential components as polyester raw materials, other essential components include the following general formula (a); RCO-N-R2.1al (in the formula, R is an aliphatic hydrocarbon group having 1 to 18 carbon atoms, R1
is a hydroxyalkyl group having 1 to 18 carbon atoms, and R2 is selected from a hydrogen atom, a hydroxyalkyl group having 1 to 18 carbon atoms, an alkyl group having 1 to 18 carbon atoms, and a dihydroxyalkyl group having 2 to 18 carbon atoms. A hydroxyl group-containing organic acid amide represented by the following formula is used. In the above formula, R representing an aliphatic hydrocarbon group may have an unsaturated bond or a hydroxyl group within the group.

The number of hydroxyl groups contained in the molecule of this organic acid amide is usually 1 to 3.

Specific examples of such hydroxyl group-containing organic acid amides include N,N-jetanollauric acid amide F'', N,N-
Dibrobanol acetamide, N, I'J-dibutanol acetate amide, N-propanol stearamide, N-lauryl alcohol butyric acid amide, etc.
One or more of these can be used.

In the present invention, an amide-modified polyester resin is produced by condensing polyester raw materials containing the above-mentioned polybasic acid, polyhydric alcohol, and hydroxyl group-containing organic acid amide as essential components by a known method. .

Here, the amount of the hydroxyl group-containing organic acid amide to be used is as follows:
0.5 to 7.0 of the total amount of all raw materials including this component
It is necessary to keep it within the range of 1% by weight, particularly preferably 1% by weight.
．． The content is preferably 0 to 5.0% by weight. If it is less than 0.5% by weight, the dispersibility of the pigment will be poor, and if it exceeds 7.0% by weight, the durability of the coating film will be poor and it may also cause discoloration of the coating film.

In the above condensation reaction, the number of carbon atoms is 8 to 1, if necessary.
Other organic acids such as the fatty acids of No. 8, dimer acid, benzoic acid, and other optional ingredients can be used for various purposes. It is preferable that the amount of these optional components used is usually suppressed to 10% by weight or less based on the total raw material.

In such polyester raw materials, the usage ratio of each component is determined by the equivalent ratio of hydroxyl groups contained in polyhydric alcohols and hydroxyl group-containing organic acid amides to acid groups contained in polybasic acids and other organic acids. , usually 1/1 to 1.
It can be appropriately selected within the range of 5/1.

The amide-modified polyester resin obtained by the condensation reaction of this polyester raw material has a hydroxyl value of 40 to 24.
0 and the number average molecular weight must be set in the range of 700 to 2,000, particularly preferably the hydroxyl value is in the range of 50 to 200 and the number average molecular weight is 900 to 1,50.
It is preferable that it be in the range of 0.

This amide-modified polyester resin has a skeleton made of polyester resin, so it has low viscosity and excellent wettability to pigments, and also has good compatibility with other resins. In addition, the hydroxyl value is 40-24
By setting the optimum solubility parameter value of 0 and setting the molecular weight within the optimum range considering the coating film forming function and compatibility with other resins, the above-mentioned good properties are further improved. This facilitates the smooth performance desired for pigment dispersion.

On the other hand, if the hydroxyl value of the polyester resin is less than 40 or exceeds 240, the compatibility with other paint resins and the durability of the coating film will decrease. Furthermore, if the number average molecular weight is less than 700, the physical properties of the resin and the weather resistance of the coating film will deteriorate, and if it exceeds 2.000, the compatibility with other coating resins will deteriorate.

In the present invention, when the above-mentioned amide-modified polyester resin is used as a resin for pigment dispersion, this resin is used as a base, a coloring pigment, an organic solvent and, if necessary, a fluidity regulator, a surface tension regulator, and a pigment dispersant. By blending etc.
Each inter (primary color paint for coloring in which a single pigment is dispersed) can be prepared.

Examples of color pigments include, but are not limited to, titanium oxide, Bengara, chrome yellow, carbon black, quinacridone pigments, perylene pigments, azo pigments, and phthalocyanine. All pigments available can be used. In Inter, the pigment concentration is designed to be higher than in normal paints in order to reduce the amount mixed into each resin paint.

Examples of organic solvents include hydrocarbons, esters,
Ketone-based, alcohol-based, cellosolve-based, etc. are used, but the solvent is not limited to these, and a wide variety of solvents commonly used for paints can be used.

(Effects of the Invention) The pigment dispersion resin of the present invention exhibits good dispersibility for various organic pigments and inorganic pigments, and also exhibits good compatibility with many resins used for paints. Inter, which has pigments dispersed in resin, can be used as room temperature drying alkyd paints, baking type amino alkyd paints, room temperature drying type acrylic paints, baking type acrylic paints, vinyl chloride paints, epoxy paints, and nitrocellulose paints. It can be used for coloring paints such as paints, and as a result, the number of types of interspersions can be greatly reduced and the productivity of paints can be significantly improved.

〔Example〕

Hereinafter, the present invention will be specifically explained with reference to Examples and Comparative Examples. Note that the section in the example is an overlapping section. In addition, the amide-modified polyester resin solutions AEI to AE4 used in the following examples and comparative examples, the amide-unmodified polyester resin? 8fgE5. E6, test acrylic varnish AC7
were prepared by the respective methods.

<Preparation of amide-modified polyester resin solution> In a flask equipped with a stirrer, rectification column, water separator cooling tube, thermometer and nitrogen gas inlet, polybasic acid, polyhydric Alcohol and hydroxyl group-containing organic acid amide were charged, heated and stirred in a nitrogen gas atmosphere, and heated to 160°C.
The temperature was raised from 230° C. to 230° C. over 4 hours while distilling the produced condensed water out of the system.

Thereafter, 1.5% by weight of xylene was gradually added to the contents of the flask, and the condensation reaction was continued while maintaining the temperature at 230°C. The reaction was terminated when the acid value became 10 or less, and the mixture was diluted with the remaining xylene to obtain four types of amide-modified polyester resin solutions AEI to AE4.

The results of measuring the number average molecular weight, hydroxyl value, and acid value of the resin component in each solution, as well as the solid content, viscosity, and color number of each solution are as shown in Table 1 below.

<Preparation of amide-unmodified polyester resin solution> Based on the formulation shown in Table 1, the procedure was exactly the same as in the case of the above-mentioned amide-modified polyester resin solution, except that the hydroxyl group-containing organic acid amide was not used as a raw material component. , two types of amide-unmodified polyester resin solutions E5. I got E6.

The results of measuring the number average molecular weight, hydroxyl value, and acid value of the resin component in both solutions, and the solid content, viscosity, and color number of each solution are as shown in Table 1 below.

<Preparation of acrylic varnish for testing> 28 parts of methyl methacrylate, 13 parts of butyl acrylate, and β methacrylate were placed in a reaction vessel containing 40 parts of xylene and 10 parts of butyl alcohol and heated to 135°C.
- A mixed solution of 5 parts of hydroxyethyl, 1 part of acrylic acid, and 1 part of cumene hydroperoxide was added dropwise over 3 hours, and stirring was continued for 2 hours at the same temperature until the solid content was 5 parts.
A test acrylic varnish AC7 containing 0% by weight was obtained.

Examples 1 to 3 and Comparative Examples 1 to 3 Amide-modified polyester resin solution AEI shown in Table 1
AE3 was added to the resin solution for pigment dispersion of the present invention (Examples 1 to 3)
and the amide-modified polyester resin solution AE4 shown in Table 1 and the amide-unmodified polyester resin tower 1fE5 shown in the same table. E6 was used as a comparative pigment dispersion resin solution (Comparative Examples 1 to 3).

Using each of these resin solutions for pigment dispersion, the following compatibility test (Test I), paint formulation test (Test ■), and color toning test (Test ■) were conducted.

Test 1; Compatibility test> Four types of general paint varnish shown in Table 2 below and each resin solution for pigment dispersion were mixed so that the resin solid content weight ratio was 8/2, After this mixed solution was flow-coated onto a glass plate, the presence or absence of cloudiness in the dried coating film was observed. Transparent samples were marked with ○ (pass), and cloudy samples were marked with × (fail).

The results were as shown in Table 2.

<Test ■; Paint formulation test> 5 Inter White 11% 1 Based on each pigment dispersion resin solution, for each 20 parts, 60 parts of titanium oxide RCR3 (IC1), 15 parts of xylene, methoxypropyl Acetate (hereinafter referred to as MP
5 parts of A) were mixed and sand milled to a particle size of 10.
6 types of inter white W1 are dispersed until it becomes less than μm.
~W6 was prepared.

1st edition] ■Old cause of failure The above Interwhite Wl-W6 was mixed in the following formulation to prepare 6 types of white coating materials WPI to WP6, and then a mixed thinner of xylene and MPA in a weight ratio of 7/3 was prepared. was used to dilute to a sprayable viscosity.

Inter white W1~W6 30 copies total
100 parts 111 Shirishitatsu The white coating materials WPI to WP6 diluted as above were applied to a zinc phosphate-treated 0.8 Tsuru x 70 m x 15 (1ws steel plate (hereinafter referred to as treated steel plate) so that the dry film thickness was 30 μm. Spray paint and heat to 140℃.

After baking for 20 minutes, the condition of the coated surface, physical properties of the coated film, and durability were evaluated. The results were as shown in Table 3 below.

<Test■; Color toning test> Based on each resin solution for dispersing pigments, add carbon black (COLOI? BLACK) to 60 parts of each resin solution.
FW200: 5 parts of Dexa), 25 parts of xylene,
Mix 100 parts of MPA and disperse with a sand mill until the particle size becomes 10 μm or less to create six types of interblack 81 to B6.
was prepared.

9 Preparation of Inter Blue Based on each pigment dispersion resin solution, phthalocyanine blue [Lionol Blue PRX,
30 parts of Toyo Ink Manufacturing Co., Ltd., 15 parts of xylene, M
Five parts of PA were mixed and dispersed in a sand mill until the particle size became 10 μm or less to prepare six types of Inter Blue F1 to F6.

@75 @i* IEI (Using the six types of white paints wpi to WP6 prepared in the Kure-kema test ■ and the above inter black 81 to B6 and inter blue F1 to F6,
Six types of toning paints P1 to P6 were prepared by mixing the following formulations and the combinations shown in Table 4.

White paint WPI-WP6 90 parts Inter black 81~B6 5 parts Inter blue F1~F
6 5 parts total
100th copy removed Physical properties and storage properties The above toning paints P1 to P6 were subjected to the following rubbing test, 60 degree specular gloss test, and standing test. The results were as shown in Table 4 below.

[Rubbing test]

The above color toning paints P1 to P6 are diluted to a sprayable viscosity with a mixed thinner of xylene and MPA in a weight ratio of 7/3, and this diluted paint is poured onto a 50w1I x 15ON tin plate, and the paint is poured at room temperature for 30 minutes. After leaving it in the room for a minute, I rubbed the painted surface with my finger and compared the difference in color with the area that was not rubbed. ○ for those with almost no color difference, × for those with large color difference
And so.

[60 degree specular gloss test] The tin plate used for the rubbing test was further heated to 40 degrees Celsius.
After baking for 20 minutes and drying, the gloss of the coating film was measured.

A score of 80 or higher was considered a pass.

[Standing Chist]

Put each diluted paint prepared in the rubbing test into a test tube,
The state of color separation was observed after 3 days. Those with almost no color separation or color floating were rated as ○, and those with severe color separation or color floating were rated as ×.

As is clear from the results in Tables 2 to 4 above, the resin for pigment dispersion of the present invention has good compatibility with various resins and exhibits good pigment dispersibility. I understand that.

Patent applicant: NOF Corporation Representative Patent Attorney Kunio Negimoto

Claims (1)

[Claims] (1) In addition to polybasic acids and polyhydric alcohols, the following general formula (a); ▲ Numerical formulas, chemical formulas, tables, etc. Hydrocarbon group, R^
1 is a hydroxyalkyl group having 1 to 18 carbon atoms, R^2 is a hydrogen atom, a hydroxyalkyl group having 1 to 18 carbon atoms, an alkyl group having 1 to 18 carbon atoms, and a dihydroxyalkyl group having 2 to 18 carbon atoms. A hydroxyl group-containing organic acid amide represented by the selected group) is an essential component, and the proportion of the above organic acid amide is 0.5 to 7.
It consists of an amide-modified polyester resin obtained by condensation reaction of 0% by weight polyester raw material, and has a hydroxyl value of 40 to 240 and a number average molecular weight of 700 to 2,000.
A resin for pigment dispersion characterized by: