JP2001026735A - Emulsion ink composition for offset printing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an emulsion ink composition for offset printing capable of sharing with an ink fountain system and keyless inking system printing machine. SOLUTION: This emulsion ink composition for offset printing including a coloring agent, a binder resin, a vegetable oil and/or a mineral oil and water as principal ingredients includes 0.1-0.5 wt.% of a higher alochol expressed by the formula R1-OH, 0.1-3.0 wt.% of a nonionic surfactant expressed by the formula R2-O-(CH2-CH2-O)n-H and 1-15 wt.% based on whole ink composition of water. In the formulas, R1 is an 8-24C saturated hydrocarbon optionally including an unsaturated bond, R2 is a 4-24C saturated hydrocarbon optionally including an unsaturated bond and/or an aromatic ring, (n) is an integer of 1-16 satisfying formula 1.5n<=k<=6n, and (k) is the number of C atoms in the R2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an emulsion ink composition for offset printing which can be used for both a fountain type and a keyless type printing machine.

[0002]

2. Description of the Related Art In recent years, machines having different ink supply systems have appeared and are used in offset printing. Typical ink supply methods include a pump method (plunger pump method, digital pump method, etc.), a crucible method, and a keyless method. The sharing between the pump method and the urn method, and the common use between the pump method and the keyless method are offset. What is possible with ink is a well-known matter.

[0003] In the printing industry (newspaper company, etc.), attention has recently been paid to simplification of the printing environment and labor saving, and a novel ink composition for offset printing that can be shared between the fountain method and the keyless method has been developed. Requested. However, as the ink composition for offset printing used in the fountain method, a relatively low fluidity is used in order to prevent dripping from the fountain when printing is stopped, while the ink composition for use in the keyless method is used. As the offset printing ink composition, those having relatively high fluidity are used from the viewpoint of ensuring fluidity in an ink pan and fluidity on a blade. As described above, since the ink compositions for offset printing used in the fountain method and the keyless method are required to have mutually contradictory properties, they cannot be shared by both methods.

[0004]

SUMMARY OF THE INVENTION In accordance with the present invention, there is provided an ink composition for offset printing which can be shared by a fountain type and a keyless type printing machine. In addition to having basic aptitude such as absorptiveness and aptitude for dirt, it also satisfies the prevention of dripping from the acupuncture point peculiar to the vase method, the ejection property from the vase, the fluidity in the ink pan peculiar to the keyless method, and the fluidity on the blade. It is an object to provide an ink composition for offset printing.

[0005]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, the following general formula (1)
In the total ink composition.
0.1 to 3.0% by weight of a nonionic surfactant represented by the following general formula (2) in all ink compositions, and water in all ink compositions. By containing 1 to 15% by weight, the aggregation rate of the pigment with respect to the shear rate can be adjusted, whereby both the suitability specific to the pot system and the suitability specific to the keyless system can be satisfied. And completed the present invention.

That is, the present invention relates to an emulsion ink composition for offset printing comprising a colorant, a binder resin, a vegetable oil and / or a mineral oil, and water as main components. 0.1 to 5.0% by weight of a higher alcohol represented by the following general formula (1) and 0.1 to 5.0% by weight of a nonionic surfactant represented by the following general formula (2).
3.0% by weight and water in the total ink composition is 1 to 1%.
The present invention relates to an emulsion ink composition for offset printing, comprising 5% by weight.

R ¹ —OH (1) R ² —O— (CH ₂ —CH ₂ —O) n—H (2) wherein R ¹ is a saturated group having a carbon number in the range of 8 to 24;
Alternatively, a hydrocarbon group which may contain an unsaturated bond is represented by R ²
The saturated carbon atoms in the range of 4 to 24, or an unsaturated bond and / or an aromatic hydrocarbon group which may contain a ring, n represents an integer ranging from 1 to 16 carbon atoms of R ² Is k, k and n satisfy the relationship of 1.5n ≦ k ≦ 6n)

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the emulsion ink composition for offset printing of the present invention will be described in detail.

The emulsion ink composition for offset printing of the present invention contains the above-mentioned general formula (1) in all the ink compositions.
0.1 to 5.0% by weight of a higher alcohol represented by the formula (1), and 0.1 to 3.0% by weight of a nonionic surfactant represented by the formula (2), and the entire ink composition It contains 1 to 15% by weight of water therein.

[0010] The emulsion ink composition for offset printing of the present invention has the following composition,
Ink does not drip from the fountain when printing is stopped, and dischargeability from the fountain is good during printing.On the other hand, the keyless method has fluidity in the ink pan and fluidity on the blade during printing. it can.

The higher alcohol used in the emulsion ink composition for offset printing of the present invention is represented by the general formula (1).

In the general formula (1), the hydrocarbon group represented by R ¹ and having 8 to 24 carbon atoms includes a linear or branched saturated aliphatic hydrocarbon group or unsaturated aliphatic hydrocarbon group. And a hydrogen group.

The higher alcohols represented by the general formula (1) include, for example, nonyl alcohol, lauryl alcohol, tridecanol, cetanol, stearyl alcohol, isostearyl alcohol, oleyl alcohol and the like having a carbon number in the range of 8 to 24. Or unsaturated monohydric alcohols. These higher alcohols can be used alone or in combination of two or more.

The higher alcohol is contained in an amount of 0.1 to 5.0 in the total amount of the emulsion ink composition for offset printing.
% By weight. If the content of the higher alcohol is less than the above range, there occurs a problem that under high shearing speed such as a nip between rollers of a printing press, water separation does not sufficiently occur and good printability cannot be obtained. When the content exceeds the above range, emulsification becomes unstable, and a problem occurs in that water separation occurs with time.

The nonionic surfactant used in the offset printing ink composition of the present invention is represented by the general formula (2).

In the general formula (2), the hydrocarbon group represented by R ² and having 4 to 24 carbon atoms includes a linear or branched saturated aliphatic hydrocarbon group or unsaturated aliphatic hydrocarbon group. An aromatic hydrocarbon group, or an aromatic hydrocarbon group having a saturated aliphatic hydrocarbon group or an unsaturated aliphatic hydrocarbon group. If the number of carbon atoms of R ^2, the number of n, and the relationship between k and n are out of the above ranges, the desired surface active effect cannot be obtained.

Examples of the nonionic surfactant represented by the general formula (2) include polyoxyethylene alkyl phenyl ethers such as ethylene oxide polyadduct of nonylphenol and ethylene oxide polyadduct of octyl phenol, and lauryl alcohol. And polyoxyethylene alkyl ethers such as ethylene oxide polyadducts. These nonionic surfactants can be used alone or in combination of two or more.

The nonionic surfactant is contained in the emulsion ink composition for offset printing in an amount of from 0.1 to 0.1%.
3.0% by weight is contained. If the content of the nonionic surfactant is less than the above range, sufficient surface activity cannot be obtained, so that a problem that water separation occurs with time in the ink pan and in the fountain occurs. A problem arises in that good printing aptitude cannot be obtained due to excessive stability.

As the binder resin component used to obtain the emulsion ink composition for offset printing of the present invention, rosin-modified phenolic resins, various alkyd resins, petroleum resins, rosin ester resins, polyester resins, gilsonite, or modifications thereof Things can be used. These resin components may be gelled using a gelling agent. These resin components can be used alone or in combination of two or more.

As the colorant for obtaining the emulsion ink composition for offset printing of the present invention, colorless or colored inorganic or organic pigments generally used for offset printing inks can be used. Inorganic pigments such as titanium, barium sulfate, calcium carbonate, and magnetic iron oxide, azo pigments, lake pigments, phthalocyanine pigments, isoindoline pigments, organic pigments such as anthraquinone pigments, quinacridone pigments, and carbon black can be used. These colorants can be used alone or in combination of two or more.

Examples of the vegetable oil for obtaining the emulsion ink composition for offset printing of the present invention include soybean oil, cottonseed oil, linseed oil, safflower oil, tung oil, tall oil, dehydrated castor oil, canola oil and the like. As the mineral oil for obtaining the emulsion ink composition for offset printing of the present invention, those used as ink solvents for offset printing can be used without particular limitation. In particular,
Petroleum solvents such as n-paraffinic solvents, isoparaffinic solvents, naphthenic solvents, aromatic solvents, α-olefins, spindle oils, machine oils and cylinder oils can be exemplified. Specific examples of other solvents that can be used together include light oil,
Examples include turpentine oil, mineral spirits, alcohols, ketones, esters and the like. These vegetable oils and mineral oils can be used alone or in combination of two or more.

Further, in order to obtain the emulsion ink composition for offset printing of the present invention, a pigment dispersant, a drying retarder, an antioxidant, a surface conditioning aid, an anti-reflection agent and the like can be appropriately used. .

The proportion of the colorant, binder resin, vegetable oil and / or mineral oil in the emulsion ink composition for offset printing of the present invention is 8 to 30% by weight of the colorant, 8 to 30% by weight of the binder resin in the total ink composition. 45% by weight,
The suitable range is 0-60% by weight of vegetable oil and 0-60% by weight of mineral oil (the total amount of vegetable oil and / or mineral oil is preferably in the range of 25-60% by weight).

As the water for obtaining the emulsion ink composition for offset printing of the present invention, ion-exchanged water, distilled water, natural water, tap water and the like can be used.

The water is contained in the emulsion ink composition for offset printing in an amount of 1 to 15% by weight. If the content of water is less than the above range, if the ink supply system is a fountain system, a problem occurs in which dripping from the fountain occurs. A problem arises in that smooth ink supply cannot be performed.

For producing the emulsion ink composition for offset printing of the present invention, a conventionally known method can be used. Hereinafter, a general production method used for obtaining the emulsion ink composition for offset printing of the present invention will be described.

A base for offset printing ink is obtained by kneading and dispersing a resin varnish, a colorant, a vegetable oil, a mineral oil and, if necessary, a pigment dispersant with a bead mill, a three-roll mill or the like.

The above-mentioned base for offset printing ink is added with the higher alcohol specified in the present invention, a nonionic surfactant, a resin varnish that can be used if necessary, and other additives as necessary, to add vegetable oils and minerals. The viscosity is adjusted to a predetermined value with oil or the like to obtain an ink composition for offset printing.

Water is added to the offset printing ink composition and stirred to obtain an offset printing emulsion ink composition.

The emulsion ink composition for offset printing of the present invention can also be used for a plunger pump type or digital pump type offset printing machine having different ink supply systems.

[0031]

The emulsion ink composition for offset printing of the present invention will be described in more detail with reference to the following Examples and Comparative Examples, but the present invention is not limited thereto unless it departs from the gist and scope of application. is not. In the following description, “parts” indicates parts by weight.

[Production of varnish for ink for offset printing] (Production of rosin-modified phenol resin gel varnish) A rosin-modified phenol resin (Hitachi Chemical Polymer Co., Ltd.) was placed in a four-necked flask equipped with a condenser, a thermometer, and a stirrer.
38.5 parts, soybean oil 3, acid value 20, softening point 162 ° C)
0 parts and 30 parts of No. 6 solvent (manufactured by Nippon Petrochemical Co., Ltd.) were charged, the temperature was raised to 230 ° C., and the mixture was stirred at the same temperature for 30 minutes and allowed to cool, and ethyl acetoacetate aluminum diisopropoxy was used as a gelling agent. (1) Charge 1.5 parts (ALCH manufactured by Kawaken Fine Chemicals Co., Ltd.) at 175 ° C and 30
The mixture was stirred for 1 minute to obtain a rosin-modified phenol resin gel varnish.

(Production of Gilsonite Varnish) Gilsonite Select (American Gilsonite Co., Ltd.) was placed in a four-necked flask equipped with a condenser, a thermometer, and a stirrer.
20 parts) and 80 parts of No. 6 solvent at 140 ° C.
Then, the mixture was stirred at the same temperature for 4 hours to obtain a Gilsonite varnish.

(Production of Petroleum Resin Varnish) Condenser,
A four-necked flask equipped with a thermometer and a stirrer was charged with 55 parts of maleated petroleum resin (manufactured by Nippon Oil Co., Ltd.) and 45 parts of No. 6 solvent, heated to 140 ° C., and stirred at the same temperature for 30 minutes. Thus, a petroleum resin varnish was obtained.

[Production of emulsion ink composition for offset printing] Examples 1 to 9, Comparative Examples 1 to 7 40 parts of rosin-modified phenol resin varnish, 12 parts of Gilsonite varnish, 12 parts of petroleum resin varnish, carbon black # 32 20 parts (Mitsubishi Chemical Co., Ltd.) and 1 part of an anti-drying agent were blended and kneaded with a bead mill to obtain a black ink base.
Next, with respect to the black ink base, a higher alcohol, a nonionic surfactant, a petroleum resin varnish,
Add No. 6 solvent and dilute to give a viscosity of 6.0-6.5P
a · s ink composition for offset printing,
Each of the offset printing ink compositions obtained above and water were stirred and mixed so as to have the composition shown in Table 1, and Examples 1 to 9,
Emulsion ink compositions for offset printing of Comparative Examples 1 to 7 were obtained.

[Performance Evaluation Test] Printing Test Offset printing was performed on the emulsion ink compositions for offset printing obtained in Examples 1 to 9 and Comparative Examples 1 to 7 under the following printing conditions, and the ink from the fountain system was used. Dripping, ink dischargeability from the fountain (judging whether the required amount of ink has been discharged from the fountain by operating the printing press for a certain period of time), ink flowability of the keyless ink pan, ink flowability on the blade, In addition, the surface of the printing paper, particularly, the stain on the non-image area was examined. Table 2 shows the results.

(Evaluation) <Drip of ink from fountain> 3: A state in which no ink drips from the fountain 2: A state in which ink drips slightly from the fountain 1: A state in which a large amount of ink drips from the fountain

<Ink ejection property from ink fountain> 3: Good ink ejection from ink fountain 2: Good ink ejection from ink fountain 1: Good ink ejection from ink fountain

<Ink fluidity on ink pan and blade> 3: Good fluidity of ink 2: Slightly poor fluidity of ink 1: Bad fluidity of ink

<State of printing paper surface> 3: A state where the printing paper surface is not stained 2: A state where the printing paper surface is slightly stained 1: A state where the printing paper surface is conspicuous

<Printing Conditions> Vase method Printing machine: Vase-type newspaper off-wheel printing press Plate material: PS plate Dampening solution: Alkaline dampening solution Paper: Newsprint Printing speed: 24,000 copies / hour to 14 10,000 copies / hour Keyless printing press: Keyless newspaper web offset press Plate material: PS plate Dampening solution: Alkaline dampening solution Paper: newsprint Printing speed: 24,000 copies / hour to 140,000 copies / hour Time

[0042]

[Table 1]

[0043]

[Table 2]

[0044]

EFFECT OF THE INVENTION The emulsion ink composition for offset printing containing the specific higher alcohol and the nonionic surfactant of the present invention and a specific amount of water is suitable for halftone dot reproducibility, inking property, and stain resistance. In addition to having basic printing suitability, such as the prevention of dripping from the vase specific to the vase method, the dischargeability from the vase, the fluidity in the ink pan, the fluidity on the blade peculiar to the keyless method, the vase method and keyless It is now possible to use it with a press-type printing press.

Continued on the front page (72) Inventor Takashi Iwase 1-23-37 Edobori, Nishi-ku, Osaka-shi F-term (reference) in Sakata Inc. Co., Ltd. AB06 AB08 AB10 AD18 AE02 AE06 AE07 AF01 BC07 BC12 BC13 BE22 CA07 EA48 GA02

Claims (1)

[Claims] 1. An emulsion ink composition for offset printing comprising a colorant, a binder resin, a vegetable oil and / or a mineral oil, and water as main components, wherein all ink compositions have the following general formula: 0.1 to 5.0% by weight of a higher alcohol represented by (1), 0.1 to 3.0% by weight of a nonionic surfactant represented by the general formula (2), and water An emulsion ink composition for offset printing, comprising 1 to 15% by weight of the ink composition. R ¹ —OH (1) R ² —O— (CH ₂ —CH ₂ —O) n—H (2) (where R ¹ is a saturated group having 8 to 24 carbon atoms,
Alternatively, a hydrocarbon group which may contain an unsaturated bond is represented by R ²
The saturated carbon atoms in the range of 4 to 24, or an unsaturated bond and / or an aromatic hydrocarbon group which may contain a ring, n represents an integer ranging from 1 to 16 carbon atoms of R ² Is k, k and n satisfy the relationship of 1.5n ≦ k ≦ 6n)