JP2000136318A - Pigment dispersant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pigment dispersant which is suitable for high-speed printing, which has been a conventional issue in the area of inks and coatings, and does not give deleterious effects on the emulsification balance at off-set printing. SOLUTION: The titled dispersant contains an aluminum-containing polymer derivative, obtained by condensing a polyester of formula I: HO-X-COOH (e.g. 12-hydroxystearic acid) which is derived from a hydroxycarboxylic acid and has a molecular weight of from 600 to 6,000 or a polyester of formula II (R1 is a 2-24C straight or branched alkyl group or alkenyl group optionally containing a hydroxyl group; p is an integer of from 2 to 11; and q is an integer of from 2 to 1,000) in an amount of from 1 to 2 equiv. in a molar ratio against aluminum contained in aluminum oxide alcoholate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a novel aluminum-containing polymer derivative used as a pigment dispersant in the field of inks and coatings.

[0002]

2. Description of the Related Art In recent years, printing technology has been remarkably advanced, and it is necessary to increase the functions of printing ink in order to achieve higher printing speed and automation of printing. When printing is performed at high speed, misting, contamination of guide rollers, and the like become problems. In order to improve these drawbacks, it is necessary to cause an appropriate gelling reaction at the time of producing a printing ink gel varnish, or to improve the dispersibility of the pigment to make the printing ink viscoelasticity appropriate. Improvements such as gelling agents and dispersants have been made.

In the production of printing inks, various additives and dispersants are usually used to improve the wetting and dispersibility of pigments, prevent sedimentation, prevent paint dripping, prevent color floating of pigments, and control fluidity. These are often used to deteriorate the viscoelastic properties of the printing ink, particularly in the case of offset printing inks, and often have a bad influence on the balance of emulsification. No results were obtained.

As a gelling agent for a printing ink, organometallic compounds such as metal soaps, aluminum chelates and aluminum oligomers are generally used, and some aluminum chelates and titanium chelates are used for printing inks and pigments. It is also used as a dispersant. But,
These dispersants are, for example, too reactive and may partially form a gel during ink production, and are difficult to handle. Therefore, these dispersants are not always optimal depending on the use.

[0005]

An object of the present invention is to provide a pigment dispersant suitable for high-speed printing, which has been a conventional problem in the field of ink and paint, and which does not adversely affect the emulsification balance in offset printing. To provide.

[0006]

Means for Solving the Problems In order to solve the above problems, the present inventors have conducted intensive studies, and as a result, have found an aluminum-containing polymer derivative having a pigment dispersing effect, and completed the present invention.

That is, the present invention relates to a compound represented by the general formula (1): HO-X-COOH (1) (wherein X has 3 to 23 carbon atoms and at least 3 carbon atoms are a hydroxy group and a carboxylic acid group) Which is a saturated or unsaturated aliphatic group existing between the above).
Polyester of 0 to 6000 or general formula (2)

[0008]

Embedded image

(Wherein R ¹ represents a linear or branched alkyl or alkenyl group which may contain a hydroxyl group having 2 to 24 carbon atoms, p represents an integer of 2 to 11, and q represents an integer of 2 to 11) A polyester dispersant containing an aluminum-containing polymer derivative obtained by subjecting a polyester represented by the following formula to an aluminum oxide alcoholate to a molar ratio of 1 to 2 equivalents with an aluminum oxide alcoholate. .

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The pigment dispersant of the present invention is suitable as a pigment dispersant for use in inks and paints, and comprises a hydroxycarboxylic acid represented by the general formula (1) or such a hydroxycarboxylic acid. Molecular weight 6 derived from a mixture of an acid and a carboxylic acid containing no hydroxy groups
00 to 6000 polyester or the general formula (2)
And an aluminum-containing polymer derivative obtained by condensing 1 to 2 equivalents of at least one polyester selected from the following polyesters with aluminum contained in aluminum oxide alcoholate.

Examples of the hydroxycarboxylic acid represented by the general formula (1) include a mixture of 9- and 10-hydroxystearic acid, 12-hydroxystearic acid, and the like. Acids are preferred.

The hydroxycarboxylic acid represented by the general formula (1) may include a carboxylic acid having no hydroxyl group. Such carboxylic acids include carboxylic acids inevitably contained in hydroxycarboxylic acids,
Examples thereof include carboxylic acids which may have a branched chain having 3 to 24 carbon atoms.

A method for producing a polyester having a molecular weight of 600 to 6000 derived from the hydroxycarboxylic acid represented by the general formula (1) is described by, for example, the hydroxycarboxylic acid of the general formula (1) (for example, 12-hydroxy of industrial grade). Xylene to stearic acid) and add 160-20
It can be manufactured by stirring at a temperature of 0 ° C., distilling off water when it is formed, and heating until a desired molecular weight is obtained.

The polyester represented by the general formula (2) is
For example, as shown in the following reaction formula, it is obtained by ring-opening polymerization of a fatty acid with a cyclic lactone by a known technique.

[0015]

Embedded image

(In the formula, R ¹ , p and q are the same as defined above.) As the conditions for the ring-opening polymerization, for example, tetrabutyl titanate is added to a mixture of ε-caprolactone and a fatty acid, and the mixture is heated to 140 ° C. It can be produced by stirring for about an hour.

Preferred examples of the fatty acid include ricinoleic acid, a mixture of 9- and 10-hydroxystearic acid, and 12-hydroxystearic acid, with 12-hydroxystearic acid being particularly preferred.

As the cyclic lactone, a cyclic lactone compound such as γ-butyrolactone and ε-caprolactone is desirable, and ε-caprolactone is particularly desirable.

The aluminum-containing polymer derivative shown in the present invention can be produced, for example, by the following method.

Polyester derived from a hydroxycarboxylic acid represented by the general formula (1) by condensation or various polyesters represented by the general formula (2) alone or in an arbitrary ratio to form an aluminum oxide alcoholate containing aluminum Is heated in a petroleum-based solvent to a temperature in the range of 150 ° C. to 250 ° C., preferably in the range of 180 to 200 ° C., and condensed while distilling off by-product alcohol. Thus, an aluminum-containing polymer derivative is obtained. If the reaction temperature is lower than 150 ° C., the obtained compound becomes a gel, which is not preferable.
If the temperature exceeds ℃, the polyester is thermally decomposed, which is not preferable.

Examples of the petroleum solvent used as the reaction solvent include K Solvent, No. 5, Solvent 7, Solvent AF-5, Solvent AF-5 (above, manufactured by Nippon Oil). .

The aluminum oxide alcoholate used at this time includes aluminum oxide isopropylate, cyclic aluminum oxide isopropylate and the like, and cyclic aluminum oxide isopropylate is particularly preferable in view of high reactivity and easy availability.

When a cyclic aluminum oxide alcoholate is used, the number of reaction sites is one for each aluminum atom. According to studies by the present inventors, the cyclic aluminum oxide alcoholate is partially reacted when the polyester is condensed. In practice, the ester can be introduced in a molar ratio of up to 2 equivalents to the aluminum atom, probably because the ring structure is cleaved. When the polyester is condensed in an amount equal to or less than 1 equivalent to aluminum containing aluminum oxide alcoholate, the dispersibility of the ink is not as effective as a conventional dispersant composed of a hydroxycarboxylic acid condensate, and when condensed in an amount of 2 equivalents or more Is not preferred because the reaction product becomes a gel. In the dispersant of the present invention, when the reaction molar ratio of the polyester to the aluminum atom is 1.0 to 2.0, the liquid and good dispersion performance are exhibited, particularly when the reaction molar ratio is 1.0 to 1.5. The highest dispersion performance can be obtained. .

When actually used in printing inks, in order to obtain performance suitable for printing, the product of the present invention is added to the printing ink so as to be about 0.1 to 10.0 wt% with respect to the pigment. I just need.

The compound of the present invention binds to a functional group such as a hydroxy group or a carboxyl group on the surface of an ink pigment by reaction or adsorption due to the high reactivity of the aluminum cyclic oligomer moiety. In addition to providing good pigment dispersibility, the color development of the pigment is greatly improved, and there is no problem of emulsification in offset printing, and the printing finish is greatly improved.

The mechanism of action of the present invention has not been elucidated in detail, but Al-OH formed in the ink vehicle.
It is considered that the residue and the polyester residue react with the resin and pigment in the offset ink, and act moderately with the fountain solution used at the time of printing to create an emulsion system suitable for printing.

Further, since the polyester residue of the compound of the present invention has good compatibility with the ink vehicle, it is considered that the dispersibility of the pigment is improved and the sharpness is improved.

Further, in dispersing inorganic pigments such as TiO ₂ , the conventional polyester-based or surfactant-based polymer dispersants did not provide sufficient dispersing effect and viscosity reduction. Could significantly improve the viscosity reduction of the blend system due to the presence of both the Al-OH residue and the polyester residue.

Although the novel aluminum-containing polymer derivative according to the present invention can be used as a pigment dispersant for inks and paints, a conventional method for preparing inks and paints using the pigment dispersant of the present invention. It is good to follow.

For example, the ink may be prepared by the following method. First, a rosin-modified phenol resin, linseed oil, and a petroleum-based solvent stirred at 200 ° C. for about 1 hour are used as a gel varnish for ink. The organic or inorganic pigment, the petroleum solvent and the product of the present invention are added to the pigment in an amount of 0.1 to 0.1%.
10.0 wt% is added, and the mixture is kneaded with a three-roll mill or the like to obtain a printing ink.

[0031]

The present invention will be described in more detail with reference to the following examples. The polyester used in the present invention was produced as follows.

Production Example 1 A mixture of 100 g of xylene and 500 g of commercially available 12-hydroxystearic acid (acid value 182.4 mg KOH / g and hydroxyl value 161.2 mg KOH / g) was mixed with 19
The mixture is stirred and reacted at 0 ° C. to 200 ° C. for 10 hours, and water generated in the reaction is separated from the distillate xylene returned to the reaction medium. After collecting 24 g of water, the xylene is removed in a stream of nitrogen for 2 hours.
Removed by heating to 00 ° C., acid value approx.
A brown viscous liquid having gKOH / g was obtained. The brown viscous liquid was measured by GPC and found to have an average molecular weight of about 16
It was a polyester of 00 (polystyrene equivalent).

Production Example 2 0.668 g of tetrabutyl titanate was added to 684.8 g of ε-caprolactone and 300.5 g of 12-hydroxystearic acid, and the mixture was stirred and reacted at 140 ° C. for 7 hours in a nitrogen atmosphere. The product was a waxy material at room temperature with an acid number of about 38.0 mg KOH / g. As a result of measuring this brown viscous liquid by GPC, the average molecular weight was about 1400.
Example 1 A 12-hydroxystearic acid polycondensate (acid value 3) obtained by the method of Production Example 1 was placed in a glass reactor having a capacity of 500 ml in terms of polystyrene.
5.0 mgKOH / g) 173.5 g (0.11 mol
l) and cyclic aluminum oxide isopropylate _{[AlO (i-C 3 H 7} O) ] ₃ 7.4 g (0.02
4 mol, contained Al 0.07 mol), 101.4 g of No. 7 solvent (manufactured by Nippon Petroleum), and a temperature of 180 to
The reaction was carried out at 200 ° C. with stirring.

Thereafter, by-produced 2-propanol was distilled off from the reaction solution to obtain 278.0 g of a solution containing the target cyclic yellow oxide viscous liquid cyclic aluminum oxide hydroxyalkanoic acid condensate acylate. This compound was soluble in solvents such as toluene, xylene and hexane.

In order to confirm the structure of the obtained product, A
1 content and IR spectrum were measured.

Al content: 0.68% (theoretical value: 0.7
%) IR spectrum ^{(cm -1): 2960~2920 (-CH} 2 - and -CH ₃ of C-H
2854 (Stretching vibration between C and H of —CH ₂ —) 1740 to 1730 (Stretching vibration between C = O) 1586 (Stretching vibration between C = C and C = O of cyclic aluminum acylate) 1465 (Symmetric bending vibration of CH ₂ ) 1440-1300 (CO stretching or OH bending vibration) 1176 (Bending vibration between CO) According to the IR measurement results, the aliphatic carboxylic acid is reacted before the reaction. C =
Absorption of stretching vibration between O (1712 cm ^-1 ) was observed, but this absorption disappeared in the obtained compound, and instead, stretching vibration between C = C and C = O of acylate (1586)
cm ^-1 ). From this, it is considered that the COOH group of the hydroxyalkanoic acid condensate reacted with the cyclic aluminum oxide to obtain the target compound.

Example 2 A polycondensate of 12-hydroxystearic acid (acid value 3) obtained by the method of Production Example 1 was placed in a glass reactor having a capacity of 300 ml.
5.0 mg KOH / g) 115.8 g (0.07 mo
l) and cyclic aluminum oxide isopropylate _{[AlO (i-C 3 H 7} O) ] ₃ 7.4 g (0.02
4 mol, contained Al 0.07 mol) and 115.8 g of No. 7 solvent (manufactured by Nippon Oil) were added, and the temperature was 180 to
The reaction was carried out at 200 ° C. with stirring.

Thereafter, the by-produced 2-propanol as a reaction liquid was distilled off to obtain 187.2 g of a solution containing the target cyclic yellow oxide viscous liquid cyclic aluminum oxide hydroxyalkanoic acid condensate acylate. This compound was soluble in solvents such as toluene, xylene and hexane. The Al content (%) of this product was 1.01% (theoretical 1.04%).

As a result of IR measurement before and after the reaction in the same manner as in Example 1, absorption of stretching vibration (1712 cm ^-1 ) between C = O of the aliphatic carboxylic acid was observed before the reaction. This absorption disappears in the obtained compound, and instead the stretching vibration between CＣC and C ＝ O of the acylate (1586 cm ⁻¹ )
Was confirmed. From this, it is considered that the COOH group of the hydroxyalkanoic acid condensate reacted with the cyclic aluminum oxide to obtain the target compound.

Example 3 A 12-hydroxystearic acid polycondensate (acid value 3) obtained by the method of Production Example 1 was placed in a glass reactor having a capacity of 300 ml.
5.0 mgKOH / g) 231.6 g (0.14 mo
l) and cyclic aluminum oxide isopropylate _{[AlO (i-C 3 H 7} O) ] ₃ 7.4 g (0.02
4 mol, contained Al 0.07 mol), and 133.9 g of No. 7 solvent (manufactured by Nippon Oil Co., Ltd.),
The reaction was carried out at 200 ° C. with stirring.

Thereafter, 2-propanol by-produced from the reaction solution was distilled off to obtain 368.6 g of a solution containing the desired yellowish brown viscous liquid cyclic aluminum oxide hydroxyalkanoic acid condensate acylate. This compound was soluble in solvents such as toluene, xylene and hexane. The Al content (%) of this product was 0.5% (theoretical 0.53%).

As a result of IR measurement before and after the reaction in the same manner as in Example 1, absorption of stretching vibration (1712 cm ⁻¹ ) between CＣO of the aliphatic carboxylic acid was observed before the reaction. This absorption disappears in the obtained compound, and instead the stretching vibration between CＣC and C ＝ O of the acylate (1586 cm ⁻¹ )
Was confirmed. From this, it is considered that the COOH group of the hydroxyalkanoic acid condensate reacted with the cyclic aluminum oxide to obtain the target compound.

Example 4 In a glass reactor having a capacity of 500 ml, the polycarbonylalkyleneoxyacid (PCAO) obtained by the method of Production Example 2 was used.
Acid) polycondensate (acid value 38.0 mgKOH / g) 147.
66 g (0.10 mol) and cyclic aluminum oxide isopropylate _{[AlO (i-C 3 H 7} O) ] ₃
10.21 g (0.10 mol) and 233.84 g of No. 7 solvent (manufactured by Nippon Oil Co., Ltd.) were charged, and the mixture was heated and reacted while stirring.

Then, 2-propanol by-produced from the reaction solution was distilled off to obtain 391.3 g of a solution containing the target cyclic aluminum oxide hydroxyalkanoic acid condensate of a yellow viscous liquid. This compound was soluble in solvents such as toluene, xylene and hexane.
The Al content (%) of this product was 0.69% (theoretical 0.7%).

As a result of IR measurement before and after the reaction in the same manner as in Example 1, absorption of stretching vibration (1712 cm ⁻¹ ) between C ＝ O of the aliphatic carboxylic acid was observed before the reaction. This absorption disappears in the obtained compound, and instead the stretching vibration between CＣC and C ＝ O of the acylate (1586 cm ⁻¹ )
Was confirmed. From this, it is considered that the COOH group of the hydroxyalkanoic acid condensate reacted with the cyclic aluminum oxide to obtain the target compound.

Comparative Example 1 A polycondensate of 12-hydroxystearic acid (acid value 3) obtained by the method of Production Example 1 was placed in a glass reactor having a capacity of 200 ml.
5.0mgzKOH / g) 25.4g (0.016mo
l) and cyclic aluminum oxide isopropylate _{[AlO (i-C 3 H 7} O) ] ₃ 16.2 g (0.05
3 mol, contained Al 0.16 mol), 23.3 g of No. 7 solvent (manufactured by Nippon Oil Co., Ltd.), and the temperature was 180 to 2
The reaction was carried out at 00 ° C. with stirring.

Thereafter, 2-propanol by-produced from the reaction solution was distilled off to obtain 63.9 g of a solution containing the desired acylate of a cyclic aluminum oxide hydroxyalkanoate as a yellow viscous liquid. This compound was soluble in solvents such as toluene, xylene and hexane. The Al content (%) of this product is 6.5% (theoretical 6.7).
%)Met.

Comparative Example 2 A 12-hydroxystearic acid polycondensate (acid value 3) obtained by the method of Production Example 1 was placed in a glass reactor having a capacity of 500 ml.
5.0 mgzKOH / g) 104.22 g (0.063)
mol) and cyclic aluminum oxide isopropylate _{[AlO (i-C 3 H 7} O) ] ₃ 7.4 g (0.0
24 mol, contained Al 0.07 mol) and 133.9 g of No. 7 solvent (manufactured by Nippon Oil Co., Ltd.)
The reaction was carried out while stirring at ~ 200 ° C.

Thereafter, 2-propanol by-produced from the reaction solution was distilled off, and then cooled to 100 ° C., and the 12-hydroxystearic acid polycondensate obtained by the method of Production Example 1 (acid value: 35.0 mgzKOH / g) 127.38 g
(0.077 mol) were mixed to obtain 368.6 g of a mixture of a target cyclic aluminum oxide hydroxyalkanoate condensate of a yellow viscous liquid and a polycondensate of 12-hydroxystearic acid. This compound was in a gel state. The Al content (%) of this product is:
0.50% (theoretical 0.54%).

When the compound synthesized in Comparative Example 2 is added to the printing ink so as to be about 0.1 to 10.0 wt% with respect to the pigment, an emulsification phenomenon occurs in offset printing, and required printing is performed. No suitability was obtained.

Example 5 (Coloring test) In order to see the effect of improving the sharpness of the novel aluminum-containing polymer derivative of the present invention in a printing ink, the novel aluminum-containing polymer derivative of the present invention (Example 1) was treated with an organic pigment. (Dainippon Seika: product name Seika First Yellow) and gel varnish (rosin-modified phenolic resin 40.0 parts, linseed oil 30.0 parts, AF7 solvent (Nippon Oil Co., Ltd. solvent)) at 200 ° C. for 1 hour Prepared by heating and stirring)
Was mixed and kneaded, and then a color test was performed.

As a result, a visual comparison with a blank to which the novel aluminum-containing polymer derivative of the present invention was not added showed that:
A clear improvement in sharpness was observed.

Example 6 (Simplified Dispersion Test) In order to examine the effect of the novel aluminum-containing polymer derivative of the present invention on the dispersing effect of the ink pigment, the novel aluminum-containing polymer derivative of the present invention (Examples 1 to 3) In a test tube, and 0.01 g of an organic pigment (manufactured by Dainippon Seika; product name: Seika First Yellow) and 10 ml of toluene were added to the test tube.
It was allowed to stand upside down with stirring 0 times, and the thickness of the dispersion layer after 2 hours was measured.

For comparison with the novel aluminum-containing polymer derivative of the present invention, a blank, the compound prepared in Comparative Example 1 and a commercially available polyester-based dispersant, 12-hydroxyoctadecanoic acid condensate (KF-1)
000, manufactured by Taiyo Kagaku, molecular weight 1200-1800), and the results are shown in Table 1.

Thickness of dispersion layer (%) = (thickness of dispersion layer /
Thickness of entire solution) x 100

[0056]

[Table 1]

The results of Table 1 show that the products of the present invention of Examples 1 to 3 have a large dispersion layer thickness (%) and good dispersibility. On the other hand, Comparative Example 1 in which the reaction molar ratio of 12-hydroxystearic acid polycondensate to aluminum containing cyclic aluminum oxide isopropylate is 0.1 equivalent or a commercially available polyester-based dispersant is compared with the product of the present invention, The dispersibility was poor.

Example 7 (Thickening test) In order to examine the effect of the novel aluminum-containing polymer derivative of the present invention on the viscosity-reducing effect of the ink pigment, the novel aluminum-containing polymer of the present invention in Examples 1 to 3 was used. The derivative is converted to an inorganic pigment (C
aCO ₃ ) was added at 0.5 wt%, and the viscosity at 25 ° C. was measured.

For the measurement, 50 g of DOP was placed in a mortar, and CaCO ₃ and a test sample were added thereto (0.5 g with respect to CaCO ₃ ).
wt%), kneaded with a pestle for 5 minutes, and using a B-type viscometer,
The viscosity was measured 15 minutes after rotating the viscometer.

The same test was carried out using blanks with inorganic pigment filling rates of 20, 30 and 50% and the compound prepared in Comparative Example 1 as a comparative example. The results are shown in Table 2.

[0061]

[Table 2]

As is evident from the results shown in Examples 5 to 7 and Tables 1 and 2, the novel pigment dispersants of the present invention have excellent or improved sharpness, dispersing ability, and reduction equivalent to or better than conventional products. Has a viscous effect.

[0063]

The novel pigment dispersant of the present invention has excellent or improved sharpness, dispersing ability and viscosity reducing effect which are equal to or better than those of conventional products, and is useful as a pigment dispersant for printing inks and paints. Useful.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Gozo Matsuda 1-3-34 Kitafu, Takefu City, Fukui Prefecture Inside Takefu Fine Chemical Co., Ltd. (72) Inventor Shoichi Aoki 1-3-34 Kitafu, Takefu City, Fukui Prefecture Takefu Fine Chemical F term in reference (reference) 4J002 CF181 CF211 CQ002 EC076 GH01 4J037 AA00 CB26 CC24 CC30 DD23 DD24 EE43 FF15 FF23 4J038 DA112 DD172 KA09 MA08 MA10 NA26

Claims (2)

[Claims] 1. A compound of the general formula (1) HO—X—COOH (1) wherein X contains 3 to 23 carbon atoms and at least 3 carbon atoms are between a hydroxy group and a carboxylic acid group. Is a saturated or unsaturated aliphatic group which is present)
0-6000 polyester or general formula (2) (In the formula, R ¹ represents a linear or branched alkyl or alkenyl group which may contain a hydroxyl group having 2 to 24 carbon atoms, p represents an integer of 2 to 11, and q represents 2 to 1000.
A pigment dispersant containing an aluminum-containing polymer derivative obtained by condensing the polyester represented by the formula (1) with an aluminum oxide alcoholate-containing aluminum in a molar ratio of 1 to 2 equivalents. 2. The pigment dispersant containing an aluminum-containing polymer derivative according to claim 1, wherein the aluminum oxide alcoholate is cyclic aluminum oxide isopropylate.