JP2006233035A - Printing ink composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dispersant which does not affect the surface tension of offset printing inks and gives the inks a high fluidity and a good dispersion stability. <P>SOLUTION: The printing ink composition is an offset printing ink consisting of 5-30 wt% of a pigment, 20-50 wt% of a binder resin, 0.05-10 wt% of a xylene-modified alkyd resin, 1-40 wt% of a vegetable oil and 1-45 wt% of a solvent. Printed matter composed of paper printed with the offset printing ink is presented. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention imparts excellent fluidity to offset printing ink (hereinafter abbreviated as “ink”) used for printed matter of paper such as books, leaflets, catalogs, etc. It relates to dispersion stability.

The xylene resin-modified alkyd resin in the present invention has a low polarity compared to a non-modified alkyd resin that has been used normally, and the addition has significantly less influence on the surface tension of the ink, and is intended to improve the dispersion stability of offset printing ink. is there.

The offset printing ink is an ink having a relatively high viscosity of about 30 to 100 Pa · sec. The mechanism of the offset printing machine is that ink is supplied from the ink fountain of the printing machine via a plurality of rollers to the image area on the printing plate. In printing with water, dampening water is supplied to the non-image area. The image area is made of a silicon layer and repels ink to form an image on paper.
Since offset ink has high viscosity and further thixotropic properties, the ink that has been allowed to stand may form a thixotropic structure (a phenomenon in which there is no dispersion stability and high contrast), or the structure formation is fast and strong. In this case, the dispersibility of the ink immediately after production is stable over time because the transferability between the rollers of the printing press is impaired and troubles due to water loss and emulsification balance are lost. There is a need.

Conventionally used dispersing agents include those similar to surfactants and those such as Solsperse (manufactured by Avicia Co., Ltd.), and among alkyd resins, the OH / COOH ratio with a biased polarity is within the scope of claim 3. Those that are far apart have a problem in transferability between rollers on the printing press due to a drop in the surface tension of the ink, water-related troubles (ink tends to be scattered in water) and poor dispersion stability over time.

The present invention has been made to solve such problems in the prior art, and the problem is that the fluidity of the ink does not affect the surface tension of the ink and maintains dispersion stability. Is to provide a good ink.

That is, the present invention comprises 5 to 30% by weight pigment, 20 to 50% by weight binder resin, 0.05 to 10% by weight xylene resin-modified alkyd resin, 1 to 40% by weight vegetable oil, and 1 to 45% by weight solvent. The present invention relates to an offset printing ink composition.
The present invention also relates to the above offset printing ink composition, wherein the xylene resin that is modifying the alkyd resin is modified with phenol.
Further, the present invention provides the offset printing ink composition described above, wherein the oil length of the xylene-modified alkyd resin is 65% to 80% and the calculated value of the OH / COOH ratio in the resin synthesis is 0.995 to 1.035. And a printed matter obtained by printing it on paper.

According to the present invention, it is possible to provide an offset printing ink composition having good dispersion stability with time and excellent fluidity without affecting the interfacial tension between the offset printing ink composition and water.

Conventionally used pigment dispersants cause problems such as water loss by significantly reducing the surface tension of ink by adding a small amount in offset printing in which an image is formed by repulsion of water and oil, and image formation is difficult for offset printing. Become.
Therefore, the OH / COOH ratio for synthesizing the alkyd resin is preferably 0.995 to 1.035, more preferably as close as possible to 1.000.

If the oil length of the xylene-modified alkyd resin is short, the alkyd resin gels (solidifies), making it difficult to knead into the ink, and excessive oil length delays the drying of the ink on paper. The oil length of the xylene-modified alkyd resin is desirably 65% to 80%.

The addition amount of the xylene-modified alkyd resin of the present invention is preferably 0.05 to 10% by weight, more preferably 1 to 3% by weight, based on the total amount of the printing ink composition. If the added amount is less than 0.05% by weight, sufficient pigment dispersion effect is not exhibited, and if the added amount exceeds 10% by weight, the printing ink becomes more oil-sensitive or causes scumming due to a decrease in ink cohesion. To do. Moreover, it is desirable that the xylene resin that has modified the alkyd resin is further modified with phenol.

The ink of the present invention comprises 5 to 30% by weight pigment, 20 to 50% by weight binder resin, 0.05 to 10% by weight xylene resin-modified alkyd resin, 1 to 40% by weight vegetable oil, and 1 to 45% by weight solvent. ing. The main types of ink are offset rotary printing press ink and sheet-fed printing press ink, but are not limited thereto.

Examples of the pigment used in the present invention include general inorganic pigments and organic pigments. Examples of inorganic pigments include yellow lead, zinc yellow, bitumen, barium sulfate, cadmium red, titanium oxide, zinc white, dial, alumina white, calcium carbonate, ultramarine, carbon black, graphite, and aluminum powder. Organic pigments include azo pigments, soluble azo pigments such as C-based (β-naphthol-based), 2B-based and 6B-based (β-oxynaphthoic), β-naphthol-based, β-oxynaphthoic acid anilide-based, monoazo yellow-based, disazo Insoluble azo pigments such as yellow and pyrazolone, condensed azo pigments such as acetoacetate allylide, phthalocyanine, copper phthalocyanine (α blue, β blue, ε blue), copper halide phthalocyanine such as chlorine and bromine, metal Examples of free phthalocyanine pigments and polycyclic pigments include perylene, perinone, quinacridone, thioindigo, dioxazine, isoindolinone, and quinophthalone pigments. The addition amount of the pigment is 5 to 30% by weight with respect to the total amount of the printing ink composition.

  The binder resin used in the present invention includes rosin-modified phenol resin, rosin-modified maleic acid resin, alkyd resin, polyester resin, petroleum resin and the like, and these can be used alone or in combination of two or more. The binder resin preferably has a cloudiness temperature of 40 to 140 ° C. in a 10% diluted state of AF Solvent 6 manufactured by Nippon Oil Corporation. (The white turbidity temperature was measured with CHEMOTRONIC, manufactured by NOVOCONTROL, Inc.) If it is less than 40 ° C., sufficient gel elasticity cannot be obtained in the state of varnish, and if it exceeds 140 ° C., the affinity with the solvent deteriorates.

As the binder resin used in the present invention, a varnish obtained by adding a vegetable oil and / or a gelling agent such as a solvent and an aluminum chelate compound and dissolving at 190 ° C. or higher can be used. The addition amount of the binder resin is 20 to 50% by weight based on the total amount of the printing ink composition.

The vegetable oils in the present invention are vegetable oils and compounds derived from vegetable oils. Among triglycerides of glycerin and fatty acids, at least one fatty acid is a fatty acid having at least one carbon-carbon unsaturated bond, and those triglycerides. Examples include fatty acid monoesters obtained by ester reaction with saturated or unsaturated alcohols, or fatty acid monoesters obtained by direct ester reaction between fatty acids of vegetable oil and monoalcohols, and ethers.

Typical vegetable oils are: Asa seed oil, flaxseed oil, eno oil, psyllium oil, olive oil, cacao oil, kapok oil, kaya oil, mustard oil, kyounin oil, kiri oil, kukui oil, walnut oil, poppy oil, sesame oil , Safflower oil, Japanese radish seed oil, soybean oil, daikon oil, camellia oil, corn oil, rapeseed oil, niger oil, nuka oil, palm oil, castor oil, sunflower oil, grape seed oil, gentian oil, pine seed oil Cottonseed oil, palm oil, peanut oil, dehydrated castor oil, and the like.

The fatty acid monoester is a fatty acid monoester obtained by transesterification of the above vegetable oil and monoalcohol or a direct ester reaction between the fatty acid of the vegetable oil and monoalcohol. Representative examples of monoalcohol include methanol, ethanol, n- or iso-propanol, n, sec or tert-butanol, heptynol, 2-ethylhexanol, hexanol, octanol, decanol, dodecanol and other saturated alcohols, oleyl alcohol, Examples thereof include unsaturated aliphatic alcohols such as dodecenol, ficesteryl alcohol, somaryl alcohol, gadrelyl alcohol, 11-icosenol, 11-docosenol, and 15-tetracosenol.

Representative examples of ethers include di-n-octyl ether, dinonyl ether, diheptyl ether, dihexyl ether, didecyl ether, nonyl hexyl ether, nonyl heptyl ether, nonyl octyl ether and the like.

The solvent used in the present invention is a crude oil-derived solvent (petroleum solvent) having an aromatic hydrocarbon content of 1% by weight or less. As the petroleum solvent, a petroleum solvent having an aniline point of 70 to 110 ° C. and a boiling point of 230 ° C. or more is suitable. When the aniline point is less than 70 ° C., the ability to dissolve the resin is too high, so that the viscosity of the ink becomes too low and the stain resistance is not sufficient. On the other hand, when the aniline point exceeds 110 ° C., the resin is poorly soluble, so that the fluidity of the ink is inferior, and as a result, only a printed matter with poor gloss and inking properties can be obtained. When the boiling point is less than 230 ° C., the amount of the solvent in the ink discharged on the printing machine increases, and the ink fluidity is deteriorated, so that the ink tends to be deposited on the roller, the plate, and the blanket. .

[Examples] Next, the present invention will be described based on examples. In the examples, “part” indicates “part by weight” and “%” indicates “% by weight”. The following examples do not limit the present invention without departing from the spirit and scope of the present invention.

(Example of varnish for offset printing ink) Stirrer, reflux condenser with water separator, 4-neck flask with thermometer, 23 parts of rosin-modified phenolic resin (Hariphenol 1248, Harima Chemical Co., Ltd.), petroleum resin (Nisseki Neo Polymer 130 manufactured by Nisseki Chemical Co., Ltd.) 20 parts, 12 parts soybean oil, 44 parts petroleum solvent (AF Solvent 7 manufactured by Nippon Oil Corporation), gelling agent (manufactured by Kawaken Fine Chemical Co., Ltd.) One part of (ALCH) was heated and stirred at 190 ° C. for 1 hour to obtain a varnish for offset printing ink.

(Example of production of offset printing ink composition) 60 parts of varnish for offset printing ink, 19 parts of carbon black (MA77 manufactured by Mitsubishi Chemical Corporation), 3 parts of (phenol-modified) xylene resin-modified alkyd resin, microcrystalline wax Add 3 parts of compound (MC-T2 compound manufactured by Morimura Chemical Co., Ltd.) and 10 parts of petroleum solvent (AF Solvent 7 manufactured by Nippon Oil Co., Ltd.). Got.

A printing ink containing 3 parts of the (phenol-modified) xylene resin-modified alkyd resin in the present invention in the production example of the offset printing ink composition was set as Example 1 in Table 1.

Examples of the offset printing ink composition are printing inks containing 3 parts of a resin-synthesized OH / COOH ratio of 1.066 in the (phenol-modified) xylene resin-modified alkyd resin of the present invention. 2.

A printing ink containing 3 parts of an unmodified alkyd resin composed of a polybasic acid, a polyhydric alcohol and a vegetable oil, which is conventionally used in the production example of the offset printing ink composition (referred to as “conventional product” in the table), It was set as Comparative Examples 1 to 4.

The printing ink which does not contain 3 parts of alkyd resin in the production example of the offset printing ink composition is referred to as Comparative Example 5.

In the production example of the offset printing ink composition, a printing ink containing 1 part of a commercially available surfactant (Kyoei Chemical Co., Ltd., Floren DOPA17) instead of 3 parts of (phenol-modified) xylene resin-modified alkyd resin, did.

(Measurement of penetration) Table 2 shows the performance evaluation results of the offset printing ink compositions of the examples and comparative examples. For the penetration of the offset printing ink composition, put the offset printing ink composition produced in Table 1 into a 100 ml metal can and leave it in an oven at room temperature (25 ° C.) and 70 ° C. for 24 hours. The time (sec) for a 3 mm metal rod to enter 3 cm ink was measured.

(Measurement of slope: JIS K-5701-1 lithographic ink, part 1 test method, fluidity) The slope of the offset printing ink composition is at room temperature (25 ° C.), and the difference between the 100-second value and the 10-second value using a spread meter. Was the slope value.

(Measurement of viscosity) A ROTO VISCO1 cone plate viscometer (25 ° C.) manufactured by HARKER was used.

(Surface Tension Measurement) Isopropyl alcohol aqueous solutions having respective concentrations (% by weight) were prepared in plastic containers, and the surface tension of the Wilhelmy method was converted from the isopropyl alcohol concentration at which ink was not scattered.

The offset printing ink composition shown in Example 1 according to the present invention in Table 2 has good penetration (normal temperature, 70 ° C.), no ink tightness, large slope value, low viscosity, and good fluidity. Is obtained.
Moreover, it has the same surface tension as Comparative Example 5, and even when the xylene resin-modified alkyd resin of the present invention is added, it does not affect the surface tension of the offset printing ink composition.

Claims (4)

Offset printing ink composition comprising 5 to 30% by weight pigment, 20 to 50% by weight binder resin, 0.05 to 10% by weight xylene resin-modified alkyd resin, 1 to 40% by weight vegetable oil, and 1 to 45% by weight solvent. . 2. The printing ink composition according to claim 1, wherein the xylene resin modifying the alkyd resin is a resin modified with phenol. The printing ink composition according to claim 1 or 2, wherein the oil length of the alkyd resin is 65% to 80%, and the calculated value of the OH / COOH ratio in the resin synthesis is 0.995 to 1.035. A printed matter obtained by printing the offset printing ink according to any one of claims 1 to 3 on paper.