JP2007254629A - Printing ink composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide offset printing ink usable for a printed product such as a book, a leaflet and a catalog, especially the ink having improved piling resistance on a blanket of a printing machine while improving friction resistance than the conventional one by complementarily formulating anti-friction agents having different physical properties, and more precisely to provide excellent printed pages and to improve the operation efficiency of printing. <P>SOLUTION: Two or more waxes are effectively formulated to improve the balance of the friction resistance, nonslip properties and piling resistance. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an offset printing ink (hereinafter abbreviated as “ink”) used for printed matter such as books, leaflets, catalogs, etc., and in particular, a friction-resistant agent having different physical properties is blended in a complementary manner. In particular, it relates to ink that has improved anti-pilling on the blanket of a printing press while improving friction resistance, and more specifically, provides an excellent printing paper surface and improves printing work efficiency. Is related to the ink.

  In offset printing, ink is supplied from an ink fountain via a plurality of rollers to a printing plate, transferred from the printing plate to a sheet via a blanket, and an image is reproduced. In the case of web offset printing, when it passes through a dryer, it receives hot air of about 180-230 ° C and evaporates, and then it is dried, passed through a guide roller, turn bar, triangular plate, etc., and folded and bound by a folding machine. In general, the paper surface may be rubbed while passing through a plurality of rollers after passing through the dryer. In particular, in recent years, as the utilization rate of recycled paper is improved, the number of papers with weak paper surface strength is increasing, and there is a situation where rubbing is more likely to occur than before. As a measure for reducing rubbing, it is common to mix an appropriate amount of wax in the ink. Wax having a particle diameter exceeding the thickness of the ink film on the paper surface has the effect of reducing rubbing.

  The dispersion-type polyethylene wax related to the present invention has excellent friction resistance even when used alone, and is excellent in non-slip properties. However, since the average particle size is generally large, it is suppressed to an amount not added to the blanket. There must be. On the other hand, existing polytetrafluoroethylene (PTFE) has strong friction resistance but low non-slip property. When blended in a large amount, it becomes slippery. There is a risk of causing an accident. As a measure for preventing such a slip accident, there is a method of blending an anti-slip agent in addition to wax in the ink (Japanese Patent Laid-Open No. 2000-178493). In addition, melt-type polyethylene wax or microcrystalline wax is effective for printing troubles such as a cooling roller being taken although it has low friction resistance.

  In recent years, the amount of mat-coated paper, which is generally low-friction-resistant paper, has increased, and the increase in recycled paper has increased the demand for inks that are more robust than conventional ones. There is also a need for inks that are difficult to induce slip accidents.

JP 2000-178493 A

  The present invention was made in order to solve such problems in the prior art, and the problem is that the problem is that the friction resistance of the paper is increased to reduce the problem of rubbing on the paper surface, and In addition, it is intended to reduce slip accidents while maintaining high friction resistance, to reduce slip accidents, and to provide ink that is difficult to piling on a blanket.

That is, according to the present invention, 0.1 to 3% by weight of a dispersible polyethylene wax as an anti-friction agent and 0.1 to 3% by weight of PTFE wax and / or microcrystalline wax and / or melt type polyethylene wax as an antifriction agent in the offset printing ink. % Offset printing ink composition.
The present invention also relates to the above offset printing ink composition, wherein the melting point of the dispersed polyethylene wax is 110 ° C. or higher and 150 ° C. or lower.
Furthermore, the present invention relates to the offset printing ink composition, wherein the average particle diameter of the dispersed polyethylene wax is 3 μm or more and 6 μm or less.
Furthermore, this invention relates to the printed matter formed by printing the said offset printing ink composition.

  According to the present invention, the friction resistance of the offset printing ink composition can be increased compared to the conventional one, and the slip property can be suppressed while maintaining high friction resistance, and the slip accident can be reduced. It is difficult to piling on the roller, and it is possible to improve the printing quality and increase the efficiency of the printing work.

  The dispersion-type polyethylene wax of the present invention is a dispersion-type polyethylene that is finely pulverized and adjusted to a predetermined particle size and then mixed with a vehicle. The amount of dispersed polyethylene added is preferably 0.1 to 3% by weight, more preferably 0.2 to 2% by weight, based on the total amount of the printing ink composition. If the addition amount is less than 0.1% by weight, sufficient friction resistance cannot be ensured. If the addition amount exceeds 3% by weight, excessive wax may be deposited on the roller or the like.

  The addition amount of PTFE wax and / or microcrystalline wax and / or melt-type polyethylene wax is preferably 0.1 to 3% by weight, more preferably 0.2 to 2% by weight, based on the total amount of the printing ink composition. . If the addition amount is less than 0.1% by weight, sufficient friction resistance cannot be secured, and if the addition amount exceeds 3% by weight, the gloss of the printed surface may be lowered.

  The melting point of the dispersible polyethylene wax according to the present invention is preferably a temperature equal to or higher than the general paper surface temperature when the printed material passes through the dryer, and specifically, 110 ° C. or higher and 150 ° C. or lower is preferable. When the melting point of the wax is less than 110 ° C., the wax may be exposed to a high temperature higher than the melting point, and the form of the particles may be significantly damaged to reduce the friction resistance. It becomes difficult to secure.

  The particle diameter of the wax relating to the present invention is preferably 3 μm or more and 6 μm or less. When the particle size of the wax is 3 μm or less, the wax particles that only provide strong friction resistance do not sufficiently appear on the surface of the printed material, and when the particle size exceeds 6 μm, there is a possibility of depositing on a roller or the like.

  The dispersed polyethylene wax name and PTFE wax according to the present invention can be used as a powder, but a compound that is previously dispersed in a vehicle and compounded may be used. In addition, microcrystalline wax and molten type polyethylene wax can be used as a waxy solid, but a compound that is previously dispersed in a vehicle and compounded may be used.

  Examples of the production of the ink in the present invention include 5 to 30% by weight of pigment, 20 to 50% by weight of binder resin, 1 to 40% by weight of vegetable oil, 1 to 45% by weight of solvent, and dispersed polyethylene wax as a friction-resistant agent. Inks comprising 1 to 3% by weight, 0.1 to 3% by weight of PTFE wax and / or microcrystalline wax and / or melt type polyethylene wax. 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. Typical examples of monoalcohol include saturated alcohols such as methanol, ethanol, n- or iso-propanol, n, sec or t-butanol, heptynol, 2-ethylhexanol, hexanol, octanol, decanol, dodecanol, and oleyl alcohol. , Unsaturated fatty alcohols such as dodecenol, husetelli 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 is increased, and the ink is liable to accumulate on the rollers, plates and blankets due to the deterioration of the fluidity of the ink. .

[Example]
Next, this invention is demonstrated based on an Example. 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 production for offset printing ink) Stirrer, reflux condenser with water separator, 4-neck flask with thermometer, 43 parts of rosin-modified phenol resin (Tamanol 420 manufactured by Arakawa Chemical Co., Ltd.), soybean oil 12 parts, 44 parts of petroleum solvent (AF solvent 7 manufactured by Nippon Oil Co., Ltd.), 1 part of gelling agent (ALCH manufactured by Kawaken Fine Chemical Co., Ltd.) are heated and stirred at 190 ° C. for 1 hour for offset printing ink A varnish was obtained.

(Production Example of Offset Printing Ink Composition) 60 parts of varnish for offset printing ink, 20 parts of carbon black (MA77 manufactured by Mitsubishi Chemical Co., Ltd.), petroleum solvent (AF Solvent 7 manufactured by Nippon Oil Corporation) 20 An offset printing ink composition was obtained using three rolls according to a conventional method.

  To the offset printing ink composition, a dispersion type polyethylene wax having an average particle diameter of 5 μ and a melting point of 128 ° C. is added and mixed so as to have the blending ratio shown in Table 1, and further PTFE having an average particle diameter of 4 μ. Wax, microcrystalline wax having a melting point of 70 ° C., and melt type polyethylene wax were added and mixed to obtain offset printing ink compositions of Examples 1 to 7.

  The offset printing ink composition was used as Comparative Example 1 as it was.

  Comparative Example 2 was obtained by adding 2% by weight of a dispersed polyethylene wax to the offset printing ink composition and mixing it.

  Comparative Example 3 was obtained by adding 3.5% by weight of dispersed polyethylene wax to the offset printing ink composition and mixing it.

  Comparative Example 4 was obtained by adding 2 wt% of PTFE wax to the offset printing ink composition and mixing.

  Comparative Example 5 was obtained by adding 2% by weight of melt type polyethylene wax to the offset printing ink composition and mixing.

  To the offset printing ink composition, 2% by weight of microcrystalline wax was added and mixed to obtain Comparative Example 6.

(Performance Evaluation Test) Table 2 shows the performance evaluation results of the offset printing ink compositions of the above examples and comparative examples. Evaluation test piece, using a front roll rotary offset inks obtained in Examples 1 to 7 and Comparative Examples 1 to 5 by Akira Seisakusho RI tester, manufactured by Mitsubishi Paper Mills at prime rate of ink of 0.3 cm ³ It was obtained by spreading the color on pearl coat A and drying it by blowing hot air in a hot air oven at a paper surface temperature of 100 ° C.

  The friction resistance was compared by combining a blank paper with the test piece and rubbing with a Toyo Seiki Gakushin type friction resistance tester with a load of 100 g and 10 reciprocations to compare the degree of rubbing of the test pieces. Relative comparisons were made in 10 stages, with 1 being the most noticeable rub and 10 having the better rub.

  The slip property was compared by overlapping the test surfaces with each other and sliding them repeatedly with a slip tester manufactured by Toyo Seiki, and comparing the seventh slip angle.

  The comparison method of roller piling is as follows. On the off-wheel printing press NEO800 manufactured by Mitsubishi Heavy Industries Ltd., the printing press is stopped after printing 50,000 copies at a rotational speed of 800 rpm, the surface of the blanket is visually confirmed, and the image area The case where the ink was not markedly piled was marked as ◯, and the case where the markedly piled was observed was marked as x.

  In Comparative Example 3 in which a large amount of disperse polyethylene wax was added, although the friction resistance was good, piling occurred remarkably. On the other hand, Example 4 had the same friction resistance and slip angle as Comparative Example 3, but no significant piling occurred. With the present invention, it is possible to improve the friction resistance, non-slip property, and piling resistance as compared with the prior art.

Claims (4)

Offset printing ink containing 0.1 to 3% by weight of dispersed polyethylene wax as a friction-resistant agent and 0.1 to 3% by weight of PTFE wax and / or microcrystalline wax and / or molten type polyethylene wax as an anti-friction agent Ink composition. The offset printing ink composition according to claim 1, wherein the melting point of the disperse polyethylene wax is 110 ° C or higher and 150 ° C or lower. The offset printing ink composition according to claim 1 or 2, wherein the dispersed polyethylene wax has an average particle size of 3 µm or more and 6 µm or less. The printed matter formed by printing the offset printing ink composition in any one of Claims 1-3.