JPH11309366A - Dispersion of fatty acid metal salt fine particle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To minimize the decrease in the pick strength of coated paper and to improve high shear fluidity by setting up the average particle size of a water- insoluble higher fatty acid metal salt in a specified range. SOLUTION: The average particle size of a substantially water-insoluble higher fatty acid metal salt, excluding salts of alkali metals, ammonium, or the like, of saturated fatty acids such as caprylic acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachinic acid, and behenic acid of the number of carbon atoms of at least 8 and unsaturated fatty acids such as octenoic acid, tetradecenoic acid, hexadecenoic acid, linoleic acid, and linolenic acid is set up at 0.05-0.7 μm. In this way, the decrease in the pick strength of coated paper is minimized, high shear fluidity can be improved, and the generation of an aggregate during high speed coating can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a fatty acid metal salt dispersion. More specifically, the present invention relates to a fatty acid metal salt dispersion having excellent effects which are qualitatively different from conventional fatty acid metal salt dispersions when used as a paper coating additive.

[0002]

2. Description of the Related Art Conventionally, there has been an increasing demand for coated paper in which a composition mainly composed of a pigment and an adhesive is coated on base paper for the purpose of improving printability. The fatty acid metal salt is used as a component of the coated paper, and imparts lubricity such as an effect of preventing dusting and a releasing effect. The average particle size of the fatty acid metal salt added to the paper coating solution is conventionally commercially available and is 2 to 2.
The range is 6 μm, but a specific measurement example is 5.6.
μm (JP-A-9-31893, No. 7
Column 37). Japanese Patent Publication No. 22800/1990 proposes a method for producing an aqueous dispersion of an alkaline earth metal salt of a carboxylic acid, and has an average particle diameter of 0.9 to 2.8 μm.
Examples of fatty acid metal salt dispersions of the above are reported.

[0003]

However, when these fatty acid metal salt dispersions are applied to paper coating solutions, various problems have been pointed out. The problem is that
For example, coated paper quality problems such as reduced pick strength of coated paper, high shear viscosity increases, resulting in poor high-speed coating suitability, and poor mechanical stability, resulting in aggregates during high-speed coating. There is a problem of operability. Insufficient performance has also been pointed out, such as the effect of preventing the dusting of calender rolls during the production of coated paper, and the insufficient releasability of the coated paper from the cast drum during the production of cast coated paper. At present, quality problems and operability problems are further exacerbated when the amount of the fatty acid metal salt added is increased to solve the above problem. As described above, the conventional fatty acid metal salt dispersion which has been used for imparting lubricity to coated paper has a serious defect in performance.

[0004]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to eliminate such defects, and as a result, have obtained fatty acid metal salts into unprecedented ultrafine particles. It has been found that it does not cause the problem of operability and the problem of operability, and that it exhibits much better lubricity than conventional metal salts of fatty acids. That is, the present invention provides a fatty acid metal salt dispersion comprising a substantially water-insoluble higher fatty acid metal salt, an emulsifying dispersant and water, wherein the average particle size of the fatty acid metal salt is 0.05 to 0.7 μm. It is a fatty acid metal salt dispersion of ultrafine particles.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, a fatty acid metal salt means a substantially water-insoluble fatty acid metal salt excluding salts of fatty acids such as alkali metals (sodium, potassium, etc.) and ammonium. Dispersions of these fatty acid alkali metal salts, ammonium salts, etc., become completely aqueous in the low concentration region when added to the paper coating solution,
Phenomena such as an increase in viscosity and an increase in foaming of the paper coating liquid occur, which is not preferable. In the fatty acid metal salt dispersion of the present invention, as the fatty acid metal salt, a saturated or unsaturated fatty acid having 8 or more carbon atoms (caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachiic acid, behenic acid) Saturated fatty acids such as octenoic acid, tetradecenoic acid, hexadecenoic acid, oleic acid, linoleic acid, unsaturated fatty acids such as linolenic acid), oxy fatty acids (12-hydroxystearic acid, fatty acids having a hydroxyl group such as ricinoleic acid), etc. Or salts of a mixture of two or more of these with magnesium, calcium, strontium, barium, zinc, cadmium, aluminum, or the like, or a mixture of these metals. Among these, preferred are magnesium, calcium, zinc, barium salts of saturated or unsaturated fatty acids having 12 to 20 carbon atoms, oxy fatty acids or a mixture of these salts, and more preferably palmitic acid, stearic acid, oleic acid. It is a calcium or zinc salt of an acid, linoleic acid or a mixture of these salts.

The average particle diameter of the fatty acid metal salt of the present invention is usually 0.05 to 0.7 μm, preferably 0.08 to 0.6 μm.
μm, and more preferably 0.1 to 0.5 μm. If the average particle diameter exceeds 0.7 μm, one or both of the problems of reduced coated paper quality and reduced operability will occur, and lubricity will also be insufficient. Even if the average particle diameter is less than 0.05 μm, the effect of the present invention hardly changes, and 0.05 μm is sufficient. In the present invention, the average particle size is defined as a laser diffraction / scattering type particle size distribution measuring device (Microtrac HRA manufactured by Leeds & Northlap Co.) or a dynamic light scattering type particle size distribution measuring device (Microtrac U manufactured by the company).
PA) means 50% cumulative average diameter.

The fatty acid metal salt dispersion of the present invention is obtained by dispersing the above fatty acid metal salt in water in the presence of an emulsifying dispersant. The emulsifying dispersant is not particularly limited as long as the produced fatty acid metal salt can be dispersed in water, and a nonionic surfactant, an anionic surfactant, a water-soluble polymer compound and the like can be used. Specifically, examples of the nonionic surfactant include polyoxyethylene alkyl phenyl ether (such as polyoxyethylene octyl phenyl ether and polyoxyethylene nonyl phenyl ether) and polyoxyethylene alkyl ether (polyoxyethylene stearyl ether, polyoxyethylene stearyl ether, Fatty acid polyethylene glycol esters (eg, polyethylene glycol laurate, polyethylene glycol oleate), fatty acid alkanolamides (eg, diethanolamide laurate, monoethanolamide stearate), and fatty acid sorbitan esters (eg, ethylene glycol secondary tridecyl ether). Sorbitan oleate,
Polyoxyethylene laurate sorbitan ester).

Examples of the anionic surfactant include sulfonates (sodium dodecylbenzenesulfonate, sodium dioctyl sulfosuccinate, sodium alpha olefin sulfonate, sodium secondary alkane sulfonate, sodium polystyrene sulfonate, formalin naphthalene sulfonate) Condensate ammonium salt, etc.), sulfate ester salt (lauryl alcohol sulfate sodium salt, polyoxyethylene lauryl ether sulfate sodium salt, polyoxyethylene nonyl phenyl ether sulfate sodium salt, etc.), phosphate ester salt (polyoxyethylene nonyl) Phenyl ether phosphate sodium salt), fatty acid alkali metal salts (sodium stearate, potassium oleate, etc.) It is below.

[0009] Examples of the water-soluble polymer compound include polyvinyl alcohol, carboxymethyl cellulose, methyl cellulose, hydroxyethyl cellulose, hydroxypropyl methyl cellulose, polyethylene oxide, and sodium polyacrylate. Of these, preferred are polyoxyethylene alkylphenyl ether, polyoxyethylene alkyl ether, sodium dodecylbenzenesulfonate, sodium salt of polyoxyethylene nonylphenyl ether sulfate, carboxymethylcellulose, hydroxypropylmethylcellulose and the like.

The amount of the emulsifying dispersant used is usually 1 to 40% by weight, preferably 2 to 30% by weight, more preferably 4 to 20% by weight, based on the solid content of the fatty acid metal salt. If the amount is less than 1% by weight, it is insufficient to stably disperse the fatty acid metal salt in water, and phenomena such as coarsening of particles and thickening occur. If it exceeds 40% by weight, the resulting fatty acid metal salt will have poor lubricity and water repellency.

In the present invention, the solid content of the fatty acid metal salt dispersion is usually from 10 to 60% by weight based on the whole dispersion.
Preferably it is 20 to 55% by weight. Solids concentration is 60
If the amount is more than 10% by weight, the viscosity of the dispersion becomes high, the mixing property and the dispersibility are inferior, and the particle size of the obtained fatty acid metal salt becomes coarse. If it is less than 10% by weight, the concentration becomes too low, and the amount of water to be added increases, so that the concentration of the paper coating liquid itself decreases.

[0012] The fatty acid metal salt dispersion of the present invention can be obtained by a melting method,
The fatty acid metal salt obtained by the metathesis method or the direct method is dispersed in water in the presence of an emulsifying dispersant, and dispersed using a disperser such as a media disperser, a high-speed stirring disperser, or a high-pressure piston disperser. And crushed. Further, it can also be obtained by a method in which an aqueous solution of an alkali metal salt of a fatty acid and an aqueous solution of a metal chloride are metathesized in the presence of an emulsifying dispersant and directly used as a dispersion.

The fatty acid metal salt dispersion obtained in the present invention contains or mixes an antioxidant, an ultraviolet absorber, a water-proofing agent, an antiseptic / fungicide, a bactericide, an antifoaming agent, a fragrance, a dye or a pigment. May be. The fatty acid metal salt dispersion of the present invention is useful as a lubricant for paper coating liquids, and is also used in paints, inks, concrete, cement boards, ceramics, etc. other than paper coating applications, as a release agent, water repellent. It can be used for the purpose of agents, anti-blocking agents, friction coefficient reducing agents, anti-wear agents, anti-scratch agents and the like.

[0014]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the present invention is limited thereto. Production Example 1 700 g of calcium stearate powder, polyoxyethylene octyl phenyl ether (ethylene oxide 1
(0 mol) 100 g and water 1200 g were mixed to obtain a calcium stearate dispersion having a solid content concentration of 40%. This dispersion was subjected to a disk bead mill using glass beads having a diameter of 0.5 mm at a disk peripheral speed of 10 m / s and a temperature of 6 mm.
Pulverization was performed by circulating at 0 to 80 ° C. for 12 hours. The average particle diameter of the obtained ultrafine calcium stearate is 0.4.
μm. This dispersion is designated as A.

Production Example 2 1265 g of water, 75 g of calcium hydroxide, 100 g of polyoxyethylene lauryl ether (9 mol of ethylene oxide) and 10 g of sodium dodecylbenzenesulfonate were added to a 2 liter four-necked flask and mixed.
Under stirring, 560 g of oleic acid heated to 40 to 50 ° C. was gradually added to carry out the reaction. After completion of the charging, the reaction was aged at 40 to 60 ° C. for 2 hours to complete the reaction. The obtained dispersion of calcium oleate was heated to 80 to 90 ° C., and the pressure was 400 kg / cm ² using a piston-type high-pressure homogenizer.
For 8 hours to carry out pulverization. The average particle size of the obtained ultrafine calcium oleate was 0.1 μm.
This dispersion is designated as B.

Production Example 3 Ultrafine particle dispersion of zinc palmitate having an average particle diameter of 0.3 μm was obtained in the same manner as in Production Example 1, except that calcium stearate was changed to zinc palmitate and the solid content was changed to 25% by weight. . This dispersion is designated as C.

Comparative Production Example 1 In Production Example 1, the conditions of the disc-type bead mill were such that the diameter of the glass beads was 2 mm, the peripheral speed of the disc was 5 m / s, the temperature was 20 to 30 ° C., and the dispersion of calcium stearate was 1
Passed. The average particle size of the obtained calcium stearate was 3.2 μm. This dispersion is designated as D.

Comparative Production Example 2 In Production Example 3, the conditions of the disk type bead mill were such that the diameter of the glass beads was 2 mm, the peripheral speed of the disk was 5 m / s, the temperature was 20 to 30 ° C., and the zinc palmitate dispersion was subjected to one pass treatment. The average particle size of the obtained zinc palmitate was 1.
It was 3 μm. This dispersion is designated as E.

Test Example 1 The fatty acid metal salt dispersion A of the present invention obtained in Preparation Example 1 and Comparative Dispersion D obtained in Comparative Preparation Example 1 were combined with a paper coating liquid to obtain mechanical stability and The suitability for high-speed coating, the stain on the super calender when the coated paper obtained by applying the coating liquid on the base paper and the super calendering treatment, and the pick strength at the time of printing were examined. The results are shown in Table 1. The evaluation method is as follows.・ Mechanical stability 90 parts by weight of clay (ultra white 90), calcium carbonate (Tamapearl TP-
222-H) 10 parts by weight, 0.1 part by weight of sodium hydroxide, 0.2 part by weight of a dispersant (SN Dispersant 5040), and 6 parts by weight of an alkali thickening type latex,
The fatty acid metal salt dispersions of the above-mentioned Production Examples and Comparative Production Examples were 0.5, 1.5, and 3.0 as solids based on 100 parts by weight of the pigment.
Parts by weight were blended. This coating liquid was treated with a Maron tester under a load of 30 kg for 20 minutes, and the residue of a 300 mesh screen was measured. The weight of the residue was expressed as a percentage of the weight of the treated coating liquid, and the smaller the numerical value, the better the mechanical stability.

High-speed coating property The above-mentioned coating liquid is applied at a speed of 1300 using a high-speed coater for experiments.
Coating at m / s and drying at 140 ° C. for 30 seconds. The high-speed coating property was evaluated by observing the surface of the obtained coated paper. The evaluation criteria are as follows. ：: There is no coating unevenness and the coating surface is uniform as a whole. Δ: Slight coating unevenness is observed in part. ×: Clear coating unevenness is observed partly or entirely. -Anti-dusting property The above-mentioned coating liquid was applied at a speed of 300 m / s so as not to cause coating unevenness, and dried at 140 ° C for 30 seconds. The coated paper thus obtained was passed once through a super calender having a temperature of 100 ° C. and a linear pressure of 150 kg / cm, and the chilled roll surface was observed and evaluated. The evaluation criteria are as follows. ：: Almost no dirt is observed on the roll surface. Δ: Slight stain is observed on the roll surface. X: Clear stain is recognized on the roll surface.・ Pick strength The coated paper applied for the evaluation of the dusting prevention property is put on a super calender at a temperature of 50 ° C. and a linear pressure of 80 kg / cm.
The paper was circulated, and the pick strength of the coated paper was measured using an RI-1 type printing test machine. The evaluation was performed by a 5-point method, and 5 (good) to 1
(Poor).

Test Example 2 The fatty acid metal salt dispersion C of the present invention obtained in Preparation Example 3 and the comparative dispersion E obtained in Comparative Preparation Example 2 were used in Test Example 1
The same evaluation was performed. The results are shown in Table 2.

[0022]

[Table 1]

[0023]

[Table 2]

Test Example 3 85 parts by weight of clay (UW-90), 15 parts by weight of calcium carbonate (Escalon 1500), 0.2 parts by weight of dispersant (SN Dispersant 5040), and 0.05 parts by weight of sodium hydroxide in terms of solid content Parts by weight, SBR latex (JS
R0696) A dispersion liquid of the present invention obtained in Production Example 2 and a comparative dispersion liquid D obtained in Comparative Production Example 1 were added to a coating liquid for cast coated paper comprising 12 parts by weight of ammonium casein and 3 parts by weight of ammonium casein. 1, 2.5 and 5 parts by weight of the solid content of the fatty acid metal salt dispersion were mixed with 100 parts by weight of the pigment. This cast coating solution was applied to base paper using a wire bar # 22, and dried at 130 ° C. for 20 seconds. At the same time water is applied to this coated paper with a brush and at a temperature of 100 ° C. and a linear pressure of 100 kg /
The paper was passed through a super calender of 2 cm and peeled off from the chill roll two seconds after passing through the nip to obtain a cast coated paper.
At this time, dirt on the chilled roll was observed to evaluate the releasability, and the pick strength of the obtained cast coated paper was evaluated. The evaluation criteria and the evaluation method are the same as those in Test Example 1. The results are shown in Table 3.

[0025]

[Table 3]

[0026]

The fatty acid metal salt dispersion of the present invention has the following effects when used as a lubricant for pigment coated paper. 1. There is almost no decrease in pick strength of coated paper. 2. It is excellent in high-speed coating suitability because the fluidity in high shear is improved. 3. Because of its excellent mechanical stability, it is possible to prevent the generation of aggregates during high-speed coating. 4. Since it has much better lubricating performance than conventional fatty acid metal salt dispersions, it exhibits good dusting prevention and releasability with a lower amount of addition than conventional fatty acid metal salt dispersions. In the present application, the fatty acid metal salt dispersion exerts a sufficient effect when added in an amount of 0.01 to 5% by weight based on the pigment as a fatty acid metal salt solid content.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI G03G 7/00 D21H 1/34 A

Claims (3)

[Claims] 1. A fatty acid metal salt dispersion comprising a substantially water-insoluble higher fatty acid metal salt, an emulsifying dispersant and water, wherein the fatty acid metal salt has an average particle size of 0.05 to 0.7 μm.
m, a dispersion of fatty acid metal salts of ultrafine particles. 2. The dispersion according to claim 1, wherein the higher fatty acid metal salt is a saturated or unsaturated fatty acid having 12 to 22 carbon atoms, or a salt of magnesium, calcium, zinc, barium or a mixture thereof. . 3. The fatty acid metal salt has an average particle size of 0.1 to less than 0.1.
3. The dispersion according to claim 1, which has a thickness of 0.5 μm.