JP2010047652A - Printing ink composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printing ink composition that is excellent in blueness, black-color impression and flowability and affords highly glossy printed matter in heat-set drying type web offset printing. <P>SOLUTION: The printing ink composition includes a carbon black (CBI) having a DBP oil absorption of 65-90 (cm<SP>3</SP>/100g) and an average primary particle size of 20-30 nm and a carbon black (CBII) having a DBP oil absorption of at most 60 (cm<SP>3</SP>/100g) and an average primary particle size of 40-60 nm with the ratio of the two carbon blacks such that the CBI/CBII weight ratio is within the range of 1/4 to 1/20, and at least 5 pts.wt. and less than 30 pts.wt., based on the whole ink, of a vegetable oil. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an offset printing ink (hereinafter abbreviated as “ink”) used for printed matter on paper such as books, leaflets, catalogs, etc., and in particular, blue that is excellent for printing ink and printed matter printed thereby. The present invention relates to an offset printing ink that imparts taste and blackness.

  The black ink used for offset printing is required to have a higher black feeling and be finished in a glossy printed matter. In a normal printing ink, the gloss and coloring power of a printed matter are expressed by mixing and dispersing carbon black in a printing ink solvent and a varnish mixture (see Non-Patent Document 1). In order to exhibit these printing ink properties, it is necessary that carbon black is sufficiently dispersed in the printing ink solvent and varnish mixture.

  In general, the carbon black used in the ink has higher coloring power and higher gloss as the primary particle diameter is smaller, but the hue is yellowish and the fluidity tends to deteriorate. Conversely, the larger the primary particle size, the weaker the coloring power, and the lower the gloss, the blue hue, and the higher the fluidity.

  However, carbon black usually exists not as primary particles but as primary aggregates called aggregates. The aggregate diameter is determined by the primary particle diameter and the degree of structure development. For example, when the primary particle diameter increases with the same structure, the aggregate diameter also increases. The larger the aggregate diameter, the worse the fluidity of the ink and the lower the gloss of the printed matter. That is, the hue depends on the primary particle diameter, and the fluidity and gloss of the ink depend on the aggregate diameter as well as the primary particle diameter. In addition, the blackness of the ink and printed matter may not correlate with the coloring power depending on the primary particle size.

Black sense of carbon black, as a method of increasing the flowability of carbon black (specific surface area by nitrogen adsorption according to Publication No. JP 2004-269572: 80~115m ² / g, DBP absorption ^{amount: 30~65cm} 3 / 100g, pH : 2-6, volatile CO / CO ₂ ratio: 1 to 1.8, volatile total oxygen content: 5~16mg / g) and the like. However, carbon black in the above range has a small primary particle size and sufficient blackness and fluidity, but the hue becomes yellowish.
Jiro Aihara, Toshio Ichimi and Yuhei Nemoto "Printing Ink Technology" CM, October 30, 1984, P131-138 JP 2004-269572 A

  The present invention provides a printing ink composition that is excellent in bluishness, blackness, fluidity, and provides a highly glossy printed matter in heat-set dry type offset rotary printing.

Printing ink composition of the present invention, the DBP oil absorption 65~90cm ³ / 100g and carbon black having characteristics of an average primary particle diameter of 20 to 30 nm (hereinafter, CBI) and, less and average DBP oil absorption 60cm ^3/100 g Carbon black (hereinafter referred to as CBII) having a primary particle diameter of 40 to 60 nm is used.

  The present invention also relates to an offset printing ink composition having a CBI / CBII weight ratio in the range of 1/4 to 1/20.

  Furthermore, this invention relates to said offset printing ink composition characterized by the vegetable oil being added in the range of 5 weight part or more and less than 30 weight part in ink.

  Furthermore, this invention relates to the printed matter formed by printing the said offset printing ink composition.

  According to the present invention, the blackness of the offset printing ink composition can be enhanced more than before, and the high fluidity can be maintained, and further, the blackness and gloss of the printed matter are improved, thereby improving the quality. A printed matter can be obtained.

  As the carbon black used in the present invention, various carbon blacks such as furnace black, channel black, thermal black, and acetylene black produced by various production facilities can be used. Moreover, although what has been surface-oxidized and what has not been used can be used, it is preferable to employ | adopt especially the carbon black which surface-treated.

  The weight of carbon black in the ink composition of the present invention may be appropriately selected according to the use, but is preferably in the range of 10 to 40 parts by weight, more preferably 15 to 25 parts by weight.

The ink composition of the present invention and CBI with the features of an average primary particle size 20~30nm and DBP oil absorption amount 65~90cm ³ / 100g, an average primary particle size 40~60nm and DBP oil absorption of 60cm ^3/100 g or less of It is realized by adopting both carbon blacks of CBII having characteristics. The DBP absorption amount conforms to JIS K6217.

  Further, the ratio of the two carbons is preferably such that the weight ratio of CBI / CBII is in the range of 1/4 to 1/20. More preferably, the weight ratio of CBI / CBII is in the range of 1/4 to 1/9. In particular, within such a range, an ink excellent in blackness, gloss and fluidity can be obtained. If the weight ratio of CBI / CBII is greater than 1/4, the hue becomes too yellow and sufficient fluidity cannot be obtained. On the other hand, when the weight ratio of CBI / CBII is smaller than 1/20, the hue becomes a bluish hue / high fluidity, but the gloss is remarkably lowered.

  The printing ink solvent used in the ink composition of the present invention is a solvent that does not contain aromatics, as long as it is a solvent suitable for printing ink, such as a high boiling point petroleum solvent, an aliphatic hydrocarbon solvent, and a higher alcohol solvent. However, it can be arbitrarily used alone or in combination of two or more.

  The petroleum solvent is mainly composed of, for example, naphthene having 14 to 18 carbon atoms and isoparaffin, and it is desirable to use a solvent that does not contain an aromatic component in consideration of the influence on the environment. The aniline point of the petroleum solvent is preferably in the range of 65 ° C. to 110 ° C. in order to maintain the performance in the ink. When a solvent having an aniline point higher than 110 ° C. is used, the solubility with the resin used in the ink composition is poor, and the fluidity of the ink becomes insufficient. In addition, in an ink using a solvent having an aniline point lower than 65 ° C., the solvent may be detached from the ink film at the time of drying, resulting in drying deterioration. Examples of such non-aromatic petroleum solvents include Nippon Oil Corporation No. 0 Solvent H, AF Solvent Nos. 4 to 7, Exxon Chemical Co., Ltd. Exol D80, D110, D130 and D160. Moreover, you may add a partially higher alcohol solvent.

  In addition to petroleum-based solvents, vegetable oils and fatty acid esters can be used.

  In the present invention, the vegetable oil may be anything as long as it is compatible with the rosin-modified phenolic resin, and examples thereof include soybean oil, cottonseed oil, linseed oil, safflower oil, tall oil, dehydrated castor oil, canola oil, and rapeseed oil. , Soybean oil, coconut oil, linseed oil and rapeseed oil are preferred, and these can be used alone or in combination of two or more.

  The vegetable oil esters used include fatty acid esters derived from vegetable oils such as soybean oil, cottonseed oil, linseed oil, safflower oil, tall oil, dehydrated castor oil, canola oil, rapeseed oil and the like. Examples of the fatty acid ester include monoalkyl ester compounds, and the fatty acid constituting the monoester is preferably a saturated or unsaturated fatty acid having 16 to 20 carbon atoms, stearic acid, isostearic acid, hydroxystearic acid, oleic acid, linol. Examples include acids, linolenic acid, eleostearic acid and the like. The alcohol-derived alkyl group constituting the fatty acid monoester preferably has 1 to 10 carbon atoms, and examples thereof include methyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, and 2-ethylhexyl. These fatty acid monoesters can be used alone or in combination of two or more.

  In the present invention, the above petroleum solvents, vegetable oils and fatty acid esters may be used in any ratio.

  The vegetable oil used for the ink composition of this invention is implement | achieved by containing in 5 to less than 30 weight part in ink. More preferably, it is contained in the range of 5 to 20 parts by weight. When the vegetable oil content is less than 5 parts by weight, the ink composition of the present invention cannot have a sufficient black feeling, and the gloss of the printed material is remarkably lowered. On the other hand, if the vegetable oil content is 30 parts by weight or more, the drying property of the printed matter is remarkably lowered, and the hot air temperature of the dryer must be increased for drying, and blisters and flames are likely to occur.

  Similarly, as a resin for printing ink varnish when producing printing ink, resin suitable for printing ink such as rosin modified phenolic resin, rosin modified maleic resin, petroleum resin, gilsonite resin, alkyd resin, etc. It can be used alone or in combination of two or more with additives.

  EXAMPLES Hereinafter, although an Example demonstrates this invention still in detail, this invention is not limited to these Examples. In the following examples, “parts” and “%” respectively represent “parts by weight” and “% by weight” unless otherwise specified.

CBI manufactured by Mitsubishi Chemical carbon black (average primary particle diameter 20~30nm and DBP oil absorption amount 65~90cm ³ / 100g carbon black having characteristics of) MA7 (average primary particle diameter 20~30nm and DBP oil absorption 65～90Cm carbon black having characteristics of ^3/100 g),
CBII Using Cabot carbon black R350 as (carbon black having an average primary particle size 40~60nm and DBP oil absorption of 60cm ^3/100 g or less features).

[Method for producing varnish]
A stirrer, a reflux condenser with a water separator, and a four-neck flask with a thermometer, 45 parts of rosin-modified phenol resin (Arakawa Chemical Industries, Ltd.), petroleum solvent (Shin Nippon Oil Co., Ltd. AF Solvent 7) ) 54 parts and 1 part of a gelling agent (ALCH manufactured by Kawaken Fine Chemical Co., Ltd.) were heated and stirred at 190 ° C. for 1 hour to obtain rosin-modified phenolic resin varnish A.

[Examples 1-4, Comparative Examples 1-4]
CBI and CBII, varnish A, petroleum solvent (AF Solvent 7 manufactured by Nippon Oil Sekiyu Co., Ltd.), vegetable oil are stirred and mixed at the mixing ratio shown in Table 1, and then kneaded with three rolls to form a base ink. The ink was adjusted so as to be 6.0. For the tack measurement, a digital incometer manufactured by Toyo Seiki Seisakusho was used, and the measurement was performed at an ink volume of 1.3 ml, a roll rotation speed of 400 rpm, and 30 ° C.

(Performance evaluation 1 fluidity)
The fluidity was evaluated as follows. The measuring instrument is composed of a hemispherical ink fountain (about 2 ml) and a flow plate. The flow plate has a structure in which the tilt can be arbitrarily tilted horizontally to vertically. The measurement method is as follows. First, the flow plate is leveled, and the well-kneaded ink for evaluation is filled into the ink fountain without excess and deficiency, and left at 25 ° C. for 15 minutes. The flow plate is then tilted vertically. Ink with good fluidity drips from the wrinkle over time, but ink with extremely poor fluidity does not drip while remaining in the tub. Measure the length of ink dripping (mm) 10 minutes after making the flow plate vertical. The longer the sagging length, the better the fluidity.

(Performance evaluation 2 Black feeling)
NEO800 manufactured by Mitsubishi Heavy Industries, Ltd. was used as an off-wheel printing machine, and printing was performed under conditions of a printing speed of 800 rpm. Oji Paper OK Coat L (765 × 1085) was used for the paper, and Toyo Ink Mfg. Co., Ltd. Akwa Unity WKK was used at a concentration of 2 parts by weight for the dampening water. The L * a * b * value of the printed matter is measured using a high-speed colorimetric spectrophotometer Spectro Photo Master CMS-35SP (manufactured by Akira Murakami Research Institute). The smaller the L * value, the stronger the blackness. Moreover, it shows that it is in a blue tendency, so that the numerical value of b * value becomes small.

(Performance evaluation 3 gloss)
After printing in the same manner as described above, the gloss value of the printed matter was measured using a gloss meter GM-26D (manufactured by Aya Murakami Research Institute). The larger the number, the higher the gloss.
(Performance Evaluation 4 Drying)
Similarly to the above, after printing, the fingertip was brought into contact with the printed material after passing through the printing machine, and the point in time when the stickiness of the surface of the printed material disappeared was assumed to be a dry state, and the paper surface temperature immediately after passing through the dryer was evaluated.

  Table 2 shows the performance evaluation test results of the black inks manufactured as examples and comparative examples. If the weight ratio of CBI / CBII is less than 1/9, the gloss of the bluish and high fluidity is remarkably lowered. It was confirmed that a yellowish hue was obtained. It was confirmed that when the vegetable oil content is less than 5 parts, the L * value of the printed matter increases and a sufficient black feeling cannot be obtained. On the other hand, it was confirmed that when the vegetable oil content exceeds 30 parts, the drying property is remarkably deteriorated. In Examples 1-4, it was an ink composition excellent in bluishness, blackness, and fluidity than Comparative Examples 1-5, and a highly glossy printed matter was obtained.

Claims (4)

Resin, DBP absorption 65~90cm ³ / 100g and an average is the primary particle size 20~30nm carbon black (hereinafter CBI) and DBP oil absorption of 60cm ^3/100 g or less and carbon black as the average primary particle size 40~60nm (Hereinafter referred to as CBII).   2. The offset printing ink composition according to claim 1, wherein the weight ratio of CBI / CBII in the offset ink is in the range of 1/4 to 1/20.   The offset printing ink composition according to claim 1 or 2, wherein vegetable oil is added to the offset ink in a range of 5 parts by weight or more and less than 30 parts by weight. A printed matter obtained by printing the offset printing ink according to claim 1 on a substrate.