JPH0125516B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an inkjet recording ink composition, and more specifically, an object of the present invention is to provide an inkjet recording ink composition that does not corrode or rust the metal when the object to be printed is made of metal. Conventionally, many inkjet recording inks are known, in which small droplets of ink are ejected from a nozzle, charged, deflected, and printed on a recording medium. salts (e.g. lithium halides, sodium nitrate,
Contains ionizable salts (sodium thiocyanate, potassium thiocyanate, etc.), so if the inkjet recording device's metal parts or the object to be printed is metal, corrosion occurs mainly on the metal parts where the print is made, causing rust. This may cause significant damage to the appearance,
There are problems such as corrosion progressing to the inside of the metal. As a result of intensive research to solve the above-mentioned drawbacks of the prior art, the inventors of the present invention have found that when a specific anti-corrosion/rust agent is included in an inkjet recording ink composition, the above-described drawbacks of the prior art can be sufficiently solved. The present invention was completed based on this knowledge. That is, the present invention comprises a coloring agent, a binding resin, a conductivity regulator, a corrosion and rust preventive agent, and an organic solvent, and the corrosion and rust preventive agent contains both the organic solvent and a mixed solvent of the organic solvent and water. Hydrophilic resins that are soluble in; organic or inorganic acid salts of aliphatic amines;
and urea, thiourea, or derivatives thereof. To explain the present invention in detail, the colorant used in the present invention is a dye or pigment conventionally used in inkjet recording ink, and any known colorant can be used. Typical examples include pigments such as carbon black, titanium oxide, phthalocyanine blue, and phthalocyanine green, and dyes such as solvent yellow 19, 21, 60, 61, 80, oil yellow, and acid yellow 11. , Solvent Red 8, 81, 82, 83, Oil Red B, Acid Red 92, Solvent Blue 11, 25, 36,
Same 117, Oil Blue G, Acid Blue 9, Solvent Black 73, Solvent Black 5, Same
22, 40, acid black 123, oil black HBB, etc. Such colorants are preferably used in the ink composition in an amount of about 5 to 30% by weight (for pigments) or about 0.2 to 4% by weight (for dyes). The binding resin used in the present invention includes:
The resin is used in conventional inkjet recording inks, and any known resin can be used. Typical examples include, for example,
Phenol resins such as novolak type phenol, resol type phenol, rosin modified phenol, alkyl modified phenol, hydrogenated rosin, and rosin resin such as its polyethylene glycol ester, polyhydric alcohol ester, rosin glycerin ester, rosin cellulose ester, alkyl cellulose , cellulose derivatives such as cellulose nitrate, ketone resins, xylene resins, acrylic resins, and the like. Such a binding resin is preferably used in an amount of about 2 to 40% by weight in the ink composition. The conductivity regulator used in the present invention is an ionic salt used in conventional inkjet recording inks, and any known ones can be used. Typical examples include sodium thiocyanate, potassium thiocyanate, ammonium thiocyanate, lithium halide, lithium nitrate, lithium nitrite, ammonium halide, and ammonium nitrite. It is preferable to use such a conductivity adjusting agent in an amount of about 0.2 to 3% by weight in the ink composition. The organic solvent used in the present invention is an organic solvent used in conventional inkjet recording inks, and any known organic solvent can be used, but preferred ones are those that dissolve the conductivity modifier described above well. Solvent, for example methanol,
Lower alcohols such as ethanol, propanol, butanol, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, esters such as methyl acetate, ethyl acetate, ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, etc. It is a mixture of Such organic solvents have a colorant concentration of about 0.2 to 30 in the ink composition.
Preferably, it is used in an amount of % by weight. The corrosion and rust preventive agents used in the present invention and which mainly characterize the present invention include the following. (1) A mixed solvent of these organic solvents and water that is soluble in the above organic solvents (mixture ratio of former: latter =
100:0.1-5) soluble resins, such as styrene-maleic acid copolymers, and their monoester derivatives such as monomethyl esters and monoethyl esters; 30-70% saponified products of polyvinyl acetate or vinyl acetate copolymers; Polyvinyl ether, polyethylene glycol, polyethylene oxide, acrylic acid copolymers, etc. (2) Aliphatic amine salts, such as methylamine, ethylamine, n-propylamine, iso-propylamine, n-butylamine, sec-butylamine, tert-butylamine, n-amylamine, iso-amylamine, n-hexylamine,
Aliphatic primary amines such as cyclohexylamine and ethanolamine, dimethylamine, diethylamine, di-iso-propylamine, di-n-
Aliphatic secondary amines such as butylamine, dicyclohexylamine, diethanolamine, piperidine, trimethylamine, triethylamine,
These are nitrites, carbonates, and carboxylates of aliphatic tertiary amines such as tributylamine, triamylamine, and triethanolamine, and preferred carboxylic acids include formic acid, acetic acid, caproic acid, lauric acid, and benzoic acid. be. (3) Urea or thiourea, adducts or derivatives of these with various inorganic substances. The anticorrosion and rust preventive agent of the present invention as described above can be used alone or as a mixture of two or more types, but it is particularly preferable to use the resin of (1) above and the amine salt of (2) in combination. It is possible to obtain corrosion and rust prevention effects. The above corrosion and rust preventive agents are contained in the ink composition from about 0.5 to
Preferably, it is used in a proportion of 3.0% by weight. The essential components of the inkjet recording ink of the present invention are as described above, but if necessary,
Known additives such as surfactants and anti-smudge agents can be added. The inkjet recording ink of the present invention can be prepared from the above-mentioned essential components and optional components using a conventionally known dispersion mixing means, such as a sand mill. (25℃), surface tension 20~60
Dyne/cm, resistivity below 2000Ωcm, specific gravity 1~
It is desirable to set it in the range of 3. The ink composition of the present invention obtained as described above can be applied and printed on various printing objects using various inkjet recording devices, but the ink composition of the present invention has a metal portion. It is suitable for use in inkjet recording devices, and is also suitable for application to iron plates, steel plates, and other metal printing bodies. In other words, when conventional ink compositions are used to print characters, etc. on metal printing materials, these inks contain conductivity modifiers that are ionizable salts, so the printing begins shortly after printing. However, when the ink composition of the present invention is used, such corrosion and corrosion can be prevented. No rust will occur. Therefore, the ink composition of the present invention is particularly suitable for recording on metallic printing objects. Next, the present invention will be specifically explained with reference to Examples. Note that "%" or "%" in the middle of the sentence is based on weight. Example 1 Titanium oxide (rutile type, Ishihara Sangyo) 10 parts Rosin-modified maleic acid resin (Hitachi Chemical) 3 parts Nitrocellulose (Daicel) 4 parts Cyclohexanone 40 parts Ethanol 40 parts Ethyl acetate 2 parts Methanol 1 part The above ingredients were mixed in a sand mill. Disperse and make the dispersion 3μ
A base ink was prepared by suctioning through a filter. The following inks A to D were prepared by adding various additives to the ink, and their physical properties were measured as shown in Table 1 below.

[Table] Using the above inks A to D, printing was done with an inkjet device on a dull steel plate (JISG-3141) that had been thoroughly cleaned with alcohol, and when the ink was left to examine the state of rust, the following Table 2 shows the results. It was like that.

【table】

[Table] From the above, the ink compositions of the present invention exhibit clear anti-corrosion and rust-preventing effects, and ink D in particular exhibits very excellent effects. Example 2 The following anticorrosion and rust prevention compositions (1) to (3) were added to Ink A of Example 1, and a rust development test was conducted in the same manner as in Example 1. 55
%, and no rust was observed even after being left at a temperature of 25°C for one week. (1) Styrene-maleic acid copolymer monoethanolamine benzoate 0.2 parts 1.0 parts (2) Polyvinyl ether (BASF) Monoethanolamine benzoate urea 0.2 parts 0.5 parts 0.2 parts (3) Polyethylene glycol cyclohexylamine carbonate 0.2 parts 0.5 part Example 3 2 parts of sodium thiocyanate (conductivity modifier) was added to 100 parts of the base ink of Example 1 to prepare ink E, and 0.8 part of styrene-maleic acid copolymer and diethanolamine laurate were added to ink E.
Ink F was prepared by adding 1.0 part. Using these inks E and F, we conducted a rusting test (relative humidity 80%, left for 3 days) in the same manner as in Example 1. In the case of ink E, the printed surface rusted, lost its luster, and developed holes. Although corrosion occurred, in the case of Ink F, no rust was observed. Example 4 Titanium oxide (rutile type, Ishihara Sangyo) 11 parts Rosin-modified xylene resin (Mitsubishi Gas Chemical) 15 parts Cyclohexanone 40 parts Ethanol 40 parts The above components were dispersed in a sand mill, and further 40 parts of ethanol and 3.6 parts of lithium nitrate were added. In addition,
Additionally, 0.5 part of polyvinyl ether (BASF) and 2 parts of dicyclohexylammonium nitrite.
part was added to prepare an ink composition of the present invention. The ink has a viscosity of 10.0 centipoise (at 25°C) and a surface tension of
It has a specific resistance of 33 dyn/cm, a specific resistance of 515 Ωcm, and a specific gravity of 1.10.A rusting test was conducted in the same manner as in Example 1.
No rust was observed even after one week of storage at a relative humidity of 80% and a temperature of 25°C.

Claims (1)

[Claims] 1 Consists of a coloring agent, a binding resin, a conductivity regulator, an anti-corrosion and rust preventive agent, and an organic solvent, and the anti-corrosion and rust preventive agent is
A hydrophilic resin soluble in both the above organic solvent and a mixed solvent of the organic solvent and water; an organic acid salt or an inorganic acid salt of an aliphatic amine; and urea or thiourea or a derivative thereof. An inkjet recording ink composition comprising at least one type of inkjet recording ink composition.