JP2002322411A - Varnish and printing ink - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide varnish effective for suppressing the overfeeding of ink by improving an ink-scraping performance compared with a conventional web offset printing ink obtained by using a rosin-modified phenolic resin for newspaper and effective for decreasing the consumption of the ink and suppressing the excessive print density, and provide a printing ink composed of the varnish. SOLUTION: The varnish contains a rosin-modified phenolic resin having a weight-average molecular weight of 40,000-200,000 and produced by the reaction of a resol resin having an average phenol nucleus number of 6-10, a rosin an/or a condensation product of a rosin and an unsaturated carboxylic acid and a polyhydric alcohol. A printing ink is also provided produced by using the varnish.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a varnish excellent in reduction of ink consumption and suppression of excessive print density in offset printing of a keyless system, and a printing ink comprising the varnish.

[0002]

2. Description of the Related Art In general, a keyless type offset printing needs to have a balance between a printing ink to be used and a dampening solution, high-speed printing suitability, workability, stable quality and economical mass-production printing. There is. Conventionally, offset ink has been used as a resin varnish that constitutes the ink, such as rosin-modified phenolic resin, rosin ester resin, maleic acid resin,
A resin containing a petroleum resin, an alkyd resin, or the like as a main component is used.

In the keyless type offset printing, a surplus ink on an ink measuring roller is scraped off by a doctor blade to secure an appropriate amount of ink and to eliminate a history of a previously formed pattern. I have. However, offset inks using these conventional resin varnishes do not always have sufficient scraping properties of the ink by the doctor blade, resulting in excessive print density, the appearance of dot gain, the occurrence of misting and ghosting, and the like. In particular, since the amount of ink deposited on the printing paper surface increases, the amount of ink used increases, and there is an economic problem in high-speed mass printing of newspapers and the like. Furthermore, in recent years, the speed of printing has been increased, and characters have been enlarged due to the readability of newsprint, and in this case, the conventional printing ink has a problem that the characters are enlarged as the characters are enlarged. Therefore, there is a demand for providing an ink varnish excellent in printing quality and economic efficiency excellent in ink scraping property, suppression of excessive print density, and printing ink comprising the varnish.

[0004]

DISCLOSURE OF THE INVENTION The present invention suppresses the excessive supply of ink due to the improvement of the ink scraping property as compared with the conventional keyless type offset ink using a rosin-modified phenol resin, thereby reducing the amount of ink used. An object of the present invention is to provide a varnish excellent in suppressing excessive print density and a printing ink comprising the varnish.

[0005]

The above object is achieved by the present invention described below. That is, the present invention provides a resol resin having an average number of phenol nuclei of 6 to 10 (component a), a rosin and / or a condensation product of rosin and an unsaturated carboxylic acid (component b), and a polyhydric alcohol ( c) and has a weight average molecular weight of 40,0
A varnish comprising a rosin-modified phenol resin (component (d)) having a varnish of from 00 to 200,000, and a printing ink using the varnish.

The present inventor has conducted intensive studies to solve the above-mentioned problems. As a result, the printing ink comprising the varnish described above has been found to have a higher printing speed than a conventional keyless offset ink using a rosin-modified phenol resin. Correspondingly, the ink scraping property with the blade is improved, and the excessive supply of the ink is suppressed, and the adjustment of the amount of the ink transferred to the printed matter becomes easy, so that the amount of the ink used is reduced, and the printing density is suppressed excessively. An excellent varnish and a printing ink comprising the varnish were found.

[0007]

Next, the present invention will be described in more detail with reference to preferred embodiments. Rosin-modified phenolic resin which mainly characterizes the present invention (hereinafter referred to as "d component")
Is a resole resin having an average number of phenol nuclei of 6 to 10 (hereinafter referred to as component a), rosin and / or a condensation product of rosin and an unsaturated carboxylic acid (hereinafter referred to as component b), and a polyhydric alcohol ( (Hereinafter referred to as component c)) to obtain a weight average molecular weight of 40,000 to 20.
It is a resin of 000.

The above-mentioned average number of phenol nuclei is defined as
1 mol of alkylphenol and 2 mol of formaldehyde are condensed at the ortho position and 1 mol of reaction water is dehydrated. The molecular weight equivalent of the model structure is defined as mononuclear, and the value of the weight average molecular weight measured by high performance liquid chromatography is defined as mononuclear. Is the quotient number divided by the number.

The component a used in the present invention is a resol resin having an average phenol number of 6 to 10 which is a condensation product of phenols and formaldehyde. Examples of the phenol constituting the component a include, for example, p-tert-butylphenol, p-secondary butylphenol, p-amylphenol, p-octylphenol,
Examples include p-alkylphenols such as p-nonylphenol and p-dodecylphenol, and phenols such as bisphenol A, phenolic acid, and cresol. Examples of the formaldehyde include aldehydes such as 37% formalin and paraformaldehyde. The aldehyde is used in an amount of 1.5 to 2.5 mol based on 1 mol of the phenol.

The component a is an inorganic or organic base such as sodium hydroxide, potassium hydroxide, calcium hydroxide, barium hydroxide, magnesium hydroxide, 25% aqueous ammonia, trimethylamine, etc., using the above-mentioned phenols and formaldehyde as catalysts. A phenol initial condensate (resole resin) having an average phenol number of less than 6 using a neutral catalyst, and further reacting the initial condensate with formaldehyde to form a resol resin having an average phenol number of 6 to 10. Alternatively, sulfuric acid, p-toluenesulfonic acid using the above phenols and formaldehyde as catalysts,
Using an acidic catalyst such as methanesulfonic acid, hydrochloric acid, phosphoric acid, and oxalic acid, a phenol initial condensate having an average phenol number of 6 or less is obtained, and the initial condensate is further treated with the above basic catalyst. Formaldehyde can be reacted to form a resole resin having an average phenol number of 6 to 10 and used.

Preferably, the above-mentioned phenols and formaldehyde are condensed in advance with 0.7 to 2.0 mol of formaldehyde per mol of phenol using the above-mentioned basic catalyst, After a resol resin having an average phenol nucleus of 4 or more and less than 6 is added, formaldehyde is further added in an amount of 0.5 to 1.8 mol, and a basic catalyst is further added. Is used as a resole resin having 6 to 10.

When the average number of phenol nuclei of the component a exceeds the upper limit, the solubility of the obtained component d in the solvent decreases and the viscosity increases, and the flow of the printing ink using the varnish increases. However, when the average number of phenolic nuclei is less than the lower limit, the scraping amount of the obtained printing ink with a blade is small, and the ink supply amount is large. Therefore, there is an economic problem such as an increase in the amount of ink used. In addition, since the obtained ink tends to be excessively supplied, there is a problem that it is difficult to adjust the amount of ink transferred to the printed matter, and that excessive print density occurs.

In the component b to be reacted with the component a,
The rosin used includes, for example, various rosins such as gum rosin, wood rosin, tall oil rosin, polymerized rosin, and disproportionated rosin. Also obtain d
In order to give the necessary molecular weight to the components, it is preferable to previously condense the rosin with unsaturated carboxylic acids (including their anhydrides). As the unsaturated carboxylic acids used, for example, maleic acid, Fumaric acid, itaconic acid,
Such as citraconic acid and their anhydrides, dimer acid,
Trimer acid, acrylic acid, methacrylic acid and the like can be mentioned.

The component c used in the present invention includes, for example, ethylene glycol, propylene glycol, trimethylene glycol, 1,4-butanediol, 1,5
-Pentanediol, 1,6-hexanediol, 1,
7-heptanediol, 1,8-octanediol,
1,9-nonanediol, 1,10-decanediol,
Examples include glycols such as hydrobenzoin and hexanediol neopentyl glycol, glycerin, polyhydric alcohols such as pentaerythritol, dipentaerythritol, trimethylolethane, trimethylolpropane, tripetaerythritol, diglycerin, and mixtures thereof. Preferably, trihydric or higher alcohols such as glycerin, trimethylolethane, trimethylolpropane, pentaerythritol and dipentaerythritol are exemplified.

The d component used in the present invention can be produced according to a known production method, and 80 to 150 parts by weight (preferably 100 to 130 parts by weight) of the b component is added to 100 parts by weight of the a component. Parts) and 5 to 15 parts by weight (preferably 8 to 13 parts by weight) of the component c.
The component has a weight average molecular weight of 40,0 in terms of polystyrene.
00 to 200,000, preferably 60,000 to 14
It is a rosin-modified phenolic resin of 000. When the weight average molecular weight of the d component exceeds the above upper limit, the solubility of the obtained d component in a solvent decreases, the viscosity of the varnish increases, and the fluidity of the printing ink obtained using the varnish decreases. Then, there is a problem that the ink physical properties required as an offset keyless ink cannot be obtained.On the other hand, when the weight average molecular weight is less than the above lower limit, there are problems such as a decrease in viscosity of the obtained varnish and development of misting. .

If necessary, a rosin-modified phenol resin, petroleum resin, alkyd resin and / or gilsonite resin having an average number of phenol nuclei of less than 6 is added to the above-mentioned component d as long as the object of the present invention is not hindered. Can be used. The amount to be added can be appropriately selected within a range that does not hinder achievement of the object of the present invention.

The varnish of the present invention can be prepared by adding a vegetable oil, a solvent, and the like to the above-mentioned component d and heating and dissolving the mixture at about 220 ° C. The printing ink of the present invention can be obtained by kneading a colorant (pigment, dye) with the varnish. As the vegetable oil used by mixing with the above d component,
For example, linseed oil, tung oil, drying oil such as safflower oil,
Semi-dry oils such as soybean oil, rapeseed oil and corn oil, non-drying oils such as castor oil and olive oil, synthetic drying oils such as dehydrated castor oil and thermally polymerized oil, and mixtures and regenerated oils thereof. In addition, the preferable content of the d component in the obtained printing ink is 2 to 30% by weight.

Examples of the solvent include petroleum solvents such as paraffin-based, naphthenic-based and aroma-based solvents such as "AF Solvent 4", "AF Solvent 5" and "AF Solvent 6" from Mitsubishi Nisseki. , "AF Solvent No. 7,""No. 6 Solvent," and "Ink Oil 35" for use in the present invention.

The varnish contains 20 to 60% by weight of d component, 20 to 40% by weight of vegetable oil, and 20% of petroleum solvent.
４０40% by weight under an atmosphere of 220 ° C.
It is obtained by mixing and stirring for about an hour. If necessary, a gelling agent can be added to form a gel varnish. Examples of the gelling agent include aluminum ethyl acetoacetate diisopropylate (manufactured by Kawaken Fine Chemicals, ALCH), aluminum tris (ethyl acetoacetate), aluminum isopropylate, aluminum stearate, aluminum octylate, and the like.
And mixtures thereof.

If necessary, additives such as anti-skinning agents and wax compounds may be added to the varnish of the present invention as long as the objects of the present invention are not hindered. The printing ink of the present invention can be uniformly mixed and dispersed by the method. The resulting ink is of the wicking dry type. As the anti-skinning agent to be used, for example, butylhydroxytoluene, cresol,
Guaiacol, methyl ethyl ketone oxime, cyclohexanone oxime and the like can be mentioned. Examples of the wax compound include waxes such as paraffin wax, carnauba wax, polyethylene wax, and polytetrafluoroethylene wax.

The pigments include, for example, inorganic pigments such as carbon black, titanium oxide, calcium carbonate, zinc white, navy blue, ultramarine blue, red iron oxide, etc .; soluble azo pigments such as lake red C and brilliant carmine 6B; Insoluble azo pigments such as allylidedisazo and pyrazolone, copper phthalocyanine blue, sulfonated copper phthalocyanine blue, quinacridone, diosazine, pyranthrone, industrone, thioindigo, anthraquinone, perinone, metal complex salts, quinophthalone, etc. And organic pigments such as polycyclic and heterocyclic pigments. The amount of the coloring agent in the printing ink is about 10 to 30% by weight.

[0022]

EXAMPLES Next, Production Examples 1 to 1 of the d component used in the present invention.
The present invention will be described more specifically with reference to Production Examples 4 to 6 of rosin-modified phenolic resins used in Comparative Example 3 and Comparative Example, and varnishes and printing inks using these. The production of these d components is not limited to the following production examples. In the description, “parts” or “%” is based on weight.

(Production Example 1) [d component] In a four-necked flask equipped with a stirrer, a reflux condenser, and a thermometer,
31 parts of toluene, 320 parts of p-octylphenol and 9
After 61 parts of 2% paraformaldehyde is charged and heated to 60 ° C. to dissolve, 1.6 parts of sodium hydroxide is added. Next, the mixture was heated to 90 ° C. and reacted for 5 hours. After confirming that resole having an average number of nuclei of 4 was formed, 16 parts of toluene was charged.
After cooling to 60 ° C, 40 parts of 92% paraformaldehyde and 6.4 parts of sodium hydroxide were charged, and after attaching a drain tube, the mixture was heated to 105 ° C and reacted for 5 hours while being dehydrated. 445 parts of resin (solid content 90%) were obtained. Next, in a four-necked flask equipped with a stirrer, a reflux condenser equipped with a water separator, and a thermometer, 600 parts of gum rosin is dissolved under a N ₂ (nitrogen) atmosphere, and the above resole resin is added dropwise over 3 hours. . Thereafter, the temperature was slowly increased at 200 ° C., 56 parts of glycerin and magnesium oxide 0.6 as a catalyst.
And heated to 260 ° C. in 7 hours, esterified at the same temperature until an acid value of 20 was reached, and converted into a rosin-modified phenol resin 9 having a weight average molecular weight of 40,000 in terms of polystyrene.
70 parts were prepared.

(Production Example 2) [d component] In a four-necked flask equipped with a stirrer, a reflux condenser, and a thermometer,
31 parts of toluene, 320 parts of p-octylphenol and 9
After charging 40 parts of 2% paraformaldehyde and heating to 60 ° C. to dissolve, 0.3 part of paratoluenesulfonic acid is added. Then, the mixture was heated to 100 ° C. and reacted while dehydrating for 5 hours. After confirming the formation of novolak having an average number of nuclei of 6, the mixture was charged with 16 parts of toluene. After charging 7.6 parts, the mixture was heated to 95 and reacted for 5 hours while dehydrating to obtain 445 parts (solid content 90%) of a resole resin having an average number of nuclei of 10. Next, in a four-necked flask equipped with a stirrer, a reflux condenser equipped with a water separator, and a thermometer, after dissolving 600 parts of gum rosin under an N ₂ (nitrogen) atmosphere, 9 parts of maleic anhydride was added at 180 ° C. Then, the above-mentioned resole resin was dropped in the same manner as in Production Example 1, and after raising the temperature, 62 parts of glycerin and 0.6 part of magnesium oxide as a catalyst were added and reacted to obtain a polystyrene-equivalent weight average molecular weight of 80. , 0
980 parts of rosin-modified phenolic resin No. 00 was prepared.

(Production Example 3) [d Component] After preparing a resole resin having an average number of nuclei of 8 in the same manner as in Production Example 1, then a stirrer, a reflux condenser with a water separator, and a thermometer were prepared. In a four-necked flask, 600 parts of gum rosin were dissolved under an N ₂ (nitrogen) atmosphere, and the above resole resin was added to 3 parts.
Drip over time. Then slowly raise the temperature to 180
At 9 ° C., 9 parts of maleic anhydride were added, 62 parts of glycerin and 0.6 part of magnesium oxide as a catalyst were added, and the temperature was raised to 260 ° C. in 7 hours, esterified at the same temperature until an acid value of 20 was reached, and polystyrene was added. Weight-average molecular weight of 120,
980 parts of a rosin-modified phenol resin were prepared.

(Production Example 4) [Rosin-modified phenol resin of Comparative Example] In a four-necked flask equipped with a stirrer, a reflux condenser, and a thermometer,
45 parts of toluene, 320 parts of p-octylphenol and 9
After 101 parts of 2% paraformaldehyde is charged and heated to 60 ° C. to dissolve, 3.2 parts of sodium hydroxide is added. Next, the mixture was heated to 90 ° C. and reacted for 5 hours to obtain 445 parts (solid content: 90%) of a resol resin having an average number of nuclei of 4.
Next, in the same manner as in Production Example 1, N was placed in a four-necked flask equipped with a stirrer, a reflux condenser equipped with a water separator, and a thermometer.
_{2 In a} (nitrogen) atmosphere, dissolve 600 parts of gum rosin, and add the above resole resin dropwise over 3 hours. Thereafter, the temperature was slowly increased, and 9 parts of maleic anhydride was added at 180 ° C.
62 parts of glycerin and 0.6 of magnesium oxide as a catalyst
And heated to 260 ° C. in 7 hours, esterified at the same temperature until the acid value reached 20, and converted to a rosin-modified phenol resin 9 having a weight average molecular weight of 60,000 in terms of polystyrene.
80 parts were prepared.

(Production Example 5) [Rosin-Modified Phenol Resin of Comparative Example] After confirming the production of resole having an average number of nuclei of 4 in the same manner as in Production Example 1, then reflux cooling with a stirrer and a water separator was carried out. In a four-necked flask equipped with a thermometer and a thermometer, 900 parts of gum rosin was dissolved under an N ₂ (nitrogen) atmosphere, and the above resole resin was added to 3 flasks.
Drip over time. Then slowly raise the temperature to 200
At 84 ° C., 84 parts of glycerin and 0.6 part of magnesium oxide as a catalyst were charged, the temperature was raised to 260 ° C. in 7 hours, esterification was carried out at the same temperature until an acid value of 20 was reached, and a polystyrene-equivalent weight average molecular weight of 20,000 was obtained. 1,260 parts of a rosin-modified phenol resin were prepared.

(Production Example 6) [Rosin-Modified Phenol Resin of Comparative Example] After confirming the production of resole having an average nucleus number of 4 by the same method as in Production Example 1, then reflux cooling with a stirrer and a water separator was carried out. In a four-necked flask equipped with a thermometer and a thermometer, 900 parts of gum rosin was dissolved under an N ₂ (nitrogen) atmosphere, and the above resole resin was added to 3 flasks.
Drip over time. Then slowly raise the temperature to 200
At 18 ° C, 18 parts of maleic anhydride, pentaerythritol 99
Parts and 0.6 parts of magnesium oxide as a catalyst, 7
The temperature was raised to 260 ° C. over time, esterified at the same temperature until the acid value reached 20, and the weight average molecular weight in terms of polystyrene was 22.
990 parts of a rosin-modified phenolic resin of 000 were prepared.

Note that d produced in the above Production Examples 1 to 3
Each acid value, softening point, measured by a known method of the components and the rosin-modified phenolic resins produced in Production Examples 4 to 6,
Table 1 shows the measured values of the viscosity, the turbid point, and the weight average molecular weight.

[0030] Viscosity: resin / soybean oil / AF Solvent No. 6 = 45/10
A varnish dissolved at 200 ° C. for 30 minutes in a ratio of / 45 (parts by weight) was measured at 25 ° C. Cloud point: 10 parts by weight of resin and Nisseki Mitsubishi No. 0 Solvent H90
The cloudiness temperature of the solution in parts by weight was measured with a chemotronic cloud point measuring device (manufactured by Novo Control).

Examples 1 to 3 and Comparative Examples 1 to 3 (Method of Preparing Varnish) The varnishes of the present invention and the comparative examples were prepared using the d component of Production Examples 1 to 3 or the rosin of Comparative Examples 4 to 6 described above. The above-mentioned vegetable drying oil and petroleum-based solvent were added to each of the modified phenolic resins, dissolved at 220 ° C. in a nitrogen stream atmosphere, and heated and stirred for 1 hour to prepare.

Examples 1 to 3 (varnishes (1) to (3)) Rosin-modified phenol resin (any one of Production Examples 1 to 3) 40.0 parts Soybean oil 30.0 parts Petroleum solvent (Nisseki) AF Solvent No. 6 manufactured by Mitsubishi Corporation) 30.0 parts

Comparative Examples 1 to 3 (varnishes (4) to (6)) Rosin-modified phenolic resin (any one of Production Examples 4 to 6) 40.0 parts Soybean oil 30.0 parts Petroleum solvent (Nisseki) AF Solvent No. 6 manufactured by Mitsubishi Corporation) 30.0 parts

Examples 4 to 6 and Comparative Examples 4 to 6 (Method of Preparing Printing Ink) Pigments, petroleum resin varnish,
A Gilsonite varnish and an ink solvent were added, and the mixture was uniformly kneaded using a sand mill. The E-type viscosity (value at 120 ° C. under the conditions of 25 ° C., cone 3 °, and 100 rpm) was 2.2 to 2.5 pa · s, glass plate flow rate (25 ° C, 10
The printing inks (V1 to V3) of the present invention and the printing inks (W1 to W3) of the comparative examples are so set that the test value 4.1.4) of the newspaper offset rotary ink is 240 mm to 270 mm according to the standard value, group standard 1998, and newspaper offset rotary ink. Prepared as in Table 2.
Each of the printing inks obtained above was evaluated for the scraping property and print density of the ink by the following measurement methods.

[0035]

(Scratchability of ink) Using each of the above printing inks, a 4N-600 type printing machine (printing speed: 120,000 parts / hour) manufactured by Higashihama Seiki Co., Ltd. Under a condition of a water content of 20%, the ink film thickness of the roll after passing through the blade was measured with a thickness gauge. Table 3 shows the evaluation results.

(Print Density) Using each of the above printing inks, a small printing machine manufactured by Higashihama Seiki Co., Ltd.
After passing the blade under the condition of an ink water content of 20%, the ink is transferred from the roll plate to the blanket and further to the printing paper (newspaper renewal), and the print density of the printed matter is measured with an X-light densitometer (X-Rite Co., Ltd.) Manufactured). Table 3 shows the evaluation results.

[0038]

[0039]

EFFECT OF THE INVENTION The varnish and printing ink of the present invention can improve the scraping property of the ink with a blade, easily adjust the transfer amount of the ink to the printing paper surface, maintain a constant printing density, The transfer amount of excess ink to the printing paper surface can be suppressed, and the amount of ink used can be reduced by 10 to 20% as compared with conventional printing inks.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C09D 193/04 C09D 193/04 201/00 201/00 (72) Inventor Fumie Yamazaki Midori-ku, Yokohama-shi, Kanagawa 450 Aotomachi F-term (reference) in The Inktec Co., Ltd. 4J038 BA201 BA202 BA231 BA232 BA242 CR012 DA041 DA042 DD122 DD232 MA07 MA09 MA14 4J039 AB04 AB06 AB10 AD18 AE02 AE06 AF01 AF03 AF07 BA04 BE01 BE12 CA04 CA07 EA48 GA02

Claims (8)

[Claims] 1. A resol resin having an average number of phenols of 6 to 10 (component (a)), rosin and / or a condensation product of rosin and unsaturated carboxylic acid (component (b)), and a polyhydric alcohol (c) A varnish, which is a reaction product of the varnish with a rosin-modified phenol resin (component (d)) having a weight average molecular weight of 40,000 to 200,000. 2. The varnish according to claim 1, wherein the component d is a reaction product of 100 parts by weight of the component a, 80 to 150 parts by weight of the component b, and 5 to 15 parts by weight of the component c. 3. The varnish according to claim 1, further comprising at least one or a plurality of rosin-modified phenol resins having an average number of phenol nuclei of less than 6, selected from petroleum resins, alkyd resins and / or Gilsonite resins. 4. The varnish according to claim 1, further comprising one or more of a vegetable oil and a petroleum-based solvent. 5. 20% to 60% by weight of the d component, 20% to
The varnish according to claim 4, comprising 40% by weight and 20 to 40% by weight of a petroleum-based solvent. 6. A varnish according to claim 1, wherein a colorant is dissolved or dispersed in the varnish.
A printing ink comprising 0% by weight. 7. The printing ink according to claim 6, wherein the printing ink is of a penetration drying type.
The printing ink according to 1. 8. A phenol is reacted with formaldehyde to produce a phenol resin precondensate having an average phenol number of 6 or less, and the product is further reacted with formaldehyde to give an average nucleus number of 6 to 10. And a condensation product (b component) of the a component with rosin and / or rosin and an unsaturated carboxylic acid;
A method for producing a rosin-modified phenolic resin having a weight average molecular weight of 40,000 to 200,000, characterized by reacting with a polyhydric alcohol (c component).