JP2856328B2 - Production method of resin for printing ink - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing a resin for printing ink.

(Prior Art) Conventionally, rosin-modified phenolic resins have been awarded as resins for printing inks, especially resins for offset printing inks. However, recently, demands for labor saving and high-speed printing have led to a strong demand for high-speed printing suitability for printing ink resins, and with this, gloss, drying properties, and performance requirements for setting have become increasingly sophisticated. I have.

In recent high-speed printing, from the viewpoint of safety and health, solvents for aromatic inks are being replaced with non-aromatic ones, so they are soluble in paraffinic solvents, and they are also soluble in glossy surfaces. On the other hand, development of highly soluble resins for printing inks has been eagerly desired.

By the way, emphasizing the gloss of printing inks and the solubility in ink solvents, conventionally, (1) a method of using a large amount of long-chain alkylphenol as a phenol component of a rosin-modified phenolic resin, (2) a higher fatty acid, a drying oil alkyd resin, A method in which a linear modifying component such as a drying oil is used in combination has been adopted. However, in general, gloss and setting and misting are contradictory performances, and it is often difficult to balance these various properties, and the setting tends to be slow by any of the above-mentioned means, and the misting resistance tends to decrease. There is.

Thus, there has been a demand for the development of a printing ink resin that maintains a certain level of gloss during high-speed printing and simultaneously satisfies the required performances (hereinafter, referred to as printability) such as drying property, setting, and misting.

(Problem to be Solved by the Invention) The present inventors can solve the problem in view of the fact that conventionally known rosin-modified phenolic resin aimed at improving gloss cannot satisfy printability during high-speed printing. A new resin for printing ink was developed.

(Means for Solving the Problems) In view of the above problems, the present inventors have focused on the molecular structure of rosin-modified phenolic resin and the like, and have conducted intensive studies on resin components and the like in order to obtain the target resin. As a result, by using a specific phenolic compound containing a carboxyl group as a resin component of the rosin-modified phenolic resin, when an ester bond is introduced into a phenol condensed chain in the obtained printing ink resin, It has been found that all the problems can be solved. The present invention has been completed based on this new finding.

That is, the present invention provides (A) a phenol, (B) a carboxyl group-containing phenol selected from the group consisting of salicylic acid, p-hydroxybenzoic acid, hydroxyphenylacetic acid, and hydroxyphenylpropionic acid, (C) a formaldehyde-supplying substance, The present invention relates to a method for producing a resin for printing ink, wherein a resin component comprising D) a rosin and a polyol (E) is subjected to a heat reaction.

(Functions and Examples) The present invention relates to a printing ink resin having a novel molecular structure that is clearly different from the molecular structure of a conventional resin. Thus, it is possible to obtain a printing ink having excellent high-speed printing suitability in which all the above-mentioned problems have been solved.

Hereinafter, the constitution of the resin for a printing ink of the present invention, a method for producing the resin, and characteristics of the obtained printing ink will be described.

The resin for a printing ink in the present invention is a phenol (hereinafter, referred to as component (A)), a carboxyl group-containing phenol selected from the group consisting of salicylic acid, p-hydroxybenzoic acid, hydroxyphenylacetic acid, and hydroxyphenylpropionic acid (hereinafter, referred to as a phenol). Component (B)), formaldehyde-supplying substance (hereinafter, referred to as Component (C)), rosin (hereinafter, referred to as Component (D)), and polyol (hereinafter, referred to as Component (E)). .

Here, the component (A) is a normal phenol, and specific examples thereof include phenol, cresol, butylphenol, amylphenol, octylphenol, and the like.
There are nonylphenol, dodecylphenol, phenylphenol, cumylphenol and the like, and among them, alkylphenol such as butylphenol, octylphenol and nonylphenol is preferable from the viewpoint of solubility.

As the component (B), salicylic acid, p-
It is at least one of hydroxybenzoic acid, hydroxyphenylacetic acid, and hydroxyphenylpropionic acid. Salicylic acid and p-hydroxybenzoic acid are preferred from the viewpoint of raw material availability. These components (B) can be used alone or in appropriate combination.

The amounts of the components (A) and (B) used are appropriately determined in consideration of the gloss, solubility, and softening point of the ink resin obtained together. The amount of component (A) used is determined by the amount of component (D) described below.
Is usually about 10 to 120 parts by weight, preferably 20 to 100 parts by weight, based on 100 parts by weight of the compound. When the amount is less than 10 parts by weight, both the solubility and the molecular weight are low, and as a result, the setting and misting are remarkably deteriorated. Also, when the amount exceeds 120 parts by weight, the setting and misting become poor.
The amount of component (B) to be used is generally about 1 to 30 parts by weight (corresponding to 1.5 to 18% by weight in a resin), preferably 2 to 25 parts by weight, per 100 parts by weight of component (D). If the amount is less than 1 part by weight, the gloss becomes insufficient, and
If the amount exceeds 30 parts by weight, there are disadvantages in that the solubility is reduced and the control of the molecular weight and the reaction becomes difficult.

As the component (C), a formaldehyde supplying substance such as formaldehyde or paraformaldehyde corresponds. The amount of component (C) used is not particularly limited,
Usually, the molar amount is about 1.0 to 3.0 times the total moles of the components (A) and (B) used.

As component (D), gum rosin, tall oil rosin,
Disproportionated rosin, polymerized rosin and the like can be mentioned. Component (D)
Is used in an amount of about 39.5 to 90% by weight, preferably 44 to 82% by weight of the obtained resin. If the used amount is less than 39.5% by weight, the setting and misting become poor, and
When the content exceeds 10% by weight, both the molecular weight and the solubility are reduced, and in this case, there is a disadvantage that the setting and misting are deteriorated.

The component (E) is not particularly limited, and various known ones can be used. Specific examples thereof include glycerin, trimethylolethane, trimethylolpropane, diethylene glycol, and pentaerythritol. The amount of the component to be used is limited to some extent because it is closely related to the solubility of the obtained resin for printing ink, and is usually up to 10% by weight, preferably up to 6% by weight, based on the resin. If it exceeds 10% by weight, the solubility is undesirably reduced.

In the present invention, the reaction method is not particularly limited as long as the above-mentioned essential components are used in a predetermined amount, and a conventionally known method for producing a rosin-modified phenol resin is employed as it is, and the ink for the object of the present invention is used. Resin can be easily obtained.

Specifically, a so-called one-step method of simultaneously charging and reacting the above components, a component (A), (B) and (C) is previously co-condensed to form a resole, and then the resole is dissolved in the presence of the component (D). , And esterification reaction with the component (E), and various methods such as a so-called dropping method can be employed. Among the above production methods, a dropping method is preferable from the viewpoint of reaction control and the like. Hereinafter, the method will be described in more detail.

That is, the predetermined amounts of the components (A), (B) and (C) are charged, and the mixture is heated to about 60 to 120 ° C. in the presence of an alkali catalyst such as sodium hydroxide, potassium hydroxide, calcium hydroxide, and ammonia. For about 2 to 8 hours to obtain an intermediate resol. Then, the intermediate resole is added dropwise and reacted with the component (D) at about 180 ° C. to 260 ° C., and the reaction product is further subjected to an esterification reaction with the component (E). Resin. The acid value of the obtained resin is usually 50 or less,
Preferably, it is 40 or less. When the acid value is more than 50, the emulsification resistance is deteriorated, and there is a tendency that troubles such as stains occur during printing. The softening point of the resin is usually 140 ° C
Or higher, preferably 150 ° C. or higher. When the temperature is lower than 140 ° C., the drying property and the setting are significantly reduced.

The solubility of the printing ink resin thus obtained is appropriately determined in consideration of the workability at the time of printing ink production and printing, and the tolerance for petroleum hydrocarbons which are usually ink solvents is usually 5 g / g. It is preferable that this is the case. Here, the tolerance refers to the amount of solvent used until 1 g of the resin is dissolved in a solvent and the dissolved substance becomes cloudy.

The printing ink resin thus obtained can be made into a printing ink by appropriately mixing various known pigments, petroleum-based solvents, drying oils, additives and the like and kneading the mixture. The ink can be used for ordinary offset printing, and can also be suitably used for letterpress printing and gravure printing. In preparing the above-mentioned ink, it is a matter of course that an appropriate amount of a known resin for printing ink such as a rosin-modified phenol resin can be used in combination.

(Examples) Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples, but it is needless to say that the present invention is not limited to only these Examples.

Example 1 A flask equipped with a stirrer, a reflux condenser equipped with a water separator and a thermometer was charged with 1000 parts of gum rosin and p-octylphenol.
Charge 600 parts, salicylic acid 100 parts, formaldehyde 200 parts, calcium hydroxide 3 parts and glycerin 100 parts,
The temperature was raised to 100 ° C. with stirring and kept for 3 hours. Then 260
C., and reacted at the same temperature until the acid value became 25 or less, to obtain about 1800 parts of a resin for a printing ink of the present invention. The acid value of this resin was 24, the softening point was 165 ° C, and the tolerance to petroleum solvents (Nippon Oil Co., Ltd., trade name “Nisseki No. 5 Solvent”) was 15 g / g at 25 ° C. .

Example 2 A flask equipped with a stirrer, a reflux condenser equipped with a water separator and a thermometer was charged with 1000 parts of p-octylphenol and salicylic acid.
170 parts, 360 parts of formaldehyde, 5 parts of calcium hydroxide, and 1300 parts of toluene were charged, and the mixture was heated to 90 ° C. with stirring and kept at that temperature for 3 hours to obtain 2600 parts of a resol solution.

1000 parts of gum rosin is charged to another similar device,
The temperature was raised to 1,400 parts of the resole solution was added dropwise with stirring at the same temperature, and the mixture was allowed to react for an hour.
The reaction was carried out until the acid value became 25 or less, to obtain about 1800 parts of a resin for printing ink which was the object of the present invention. The acid value of this resin is 2
4. The softening point was 168 ° C, and the tolerance to the petroleum solvent was 10 g / g at 25 ° C.

Examples 3 to 5 In Example 1, the reaction was carried out in the same manner as in Example 1 except that the component (B) shown in Table 1 was used instead of salicylic acid 100 parts. Obtained. The resin constants are shown in Table 1.

Examples 6 to 7 In Example 2, a reaction was carried out in the same manner as in Example 2 except that a part of p-octylphenol was changed to a composition as shown in Table 1, and a resin for a printing ink aimed at by the present invention was obtained. I got The resin constants are shown in Table 1.

Examples 8 to 9 The reaction was carried out in the same manner as in Example 1 except that the amount of salicylic acid used was changed as shown in Table 1, to obtain a resin for printing ink which was the object of the present invention. The resin constants are shown in Table 1.

Comparative Example 1 A conventional rosin-modified phenol resin (trade name “Tamanol 366” manufactured by Arakawa Chemical Industries, Ltd.) was used. The resin constants are shown in Table 1.

Using the printing ink resin obtained in Examples 1 to 9 and the comparative printing ink resin obtained in Comparative Example 1, ink preparation was performed by the following method, and their ink performance was evaluated. The evaluation results are shown in Table 2.

(Ink Preparation) A varnish was obtained by mixing and dissolving 45 parts of resin, 20 parts of linseed oil and 30 parts of Nisseki No. 5 solvent. Using this varnish, the ink was kneaded with three rolls at the following mixing ratio to obtain an ink.

Carmine 6B (Red Pigment) 20 parts Varnish 65-70 parts Nisseki No. 5 Solvent 4-9 parts Friction resistance improver (wax compound) 5 parts Ink dryer 1 part Based on the above formulation, the tack value of the ink is 9 The values were adjusted appropriately so that the flow value was ± 0.5 and the flow value was 18 ± 0.5.

(Performance test) Gloss: 0.4 ml of ink was spread on art paper by RI Tester (Meiji Seisakusho Co., Ltd.) and then conditioned at 20 ° C and 65% RH for 24 hours. The reflectance was measured with a gloss meter.

Set: After 0.4 ml of ink is spread on art paper by RI tester (manufactured by Akira Seisakusho Co., Ltd.), the developed product is divided every hour, and it is separated from the developed product on another art paper using RI tester roller. The degree of adhesion of the ink to the ink was observed, and the time (minutes) until the ink no longer adhered was measured.

Misting: Charge 4 ml of ink into the incometer, rotate at 400 rpm for 1 minute, and further rotate at 1200 rpm for 3 minutes,
The degree of scattering of the ink on the white paper placed immediately below the roll was observed.

(Effect of the Invention) The resin for printing ink obtained in the present invention is a remarkable improvement over the drawbacks of the conventionally known rosin-modified phenolic resin. That is, even under high-speed printing, printability such as gloss, setting, misting and the like can be sufficiently satisfied, and a printing ink that meets today's demands for high-speed printing and the like can be provided.

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Claims (2)

(57) [Claims] (1) phenols, (B) salicylic acid,
at least one carboxyl group-containing phenol selected from the group consisting of p-hydroxybenzoic acid, hydroxyphenylacetic acid, and hydroxyphenylpropionic acid;
A method for producing a resin for printing ink, wherein a resin component comprising (C) a formaldehyde supply substance, (D) a rosin, and (E) a polyol is heated and reacted. 2. The method for producing a resin for printing inks according to claim 1, wherein said phenol containing a carboxyl group is contained in the resin in an amount of 1.5 to 18% by weight.