JPH011777A - Sterile display ink composition for inkjet recording - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention The present invention relates to an ink composition for indicating sterilization for inkjet recording, and more specifically, for example, for inkjet printing on the lid or bottom of a can of a can of a canned beverage such as canned coffee. The present invention relates to an ink composition for indicating sterilization for inkjet recording, which indicates the degree of sterilization by changing the color of the printing when necessary information is printed in a recording method and then heated in a heat sterilizer.

In recent years, canned beverages such as canned coffee are produced after filling the can with coffee and printing necessary information such as the loft number and date of manufacture on the lid or bottom of the can using an inkjet recording method. It is sold after being heated and sterilized with steam in a sterilizer such as an autoclave. However, since a large number of cans are usually placed in a sterilizer, there is a risk that not all cans will be sufficiently heat sterilized. Already, in the sterilization of surgical instruments, etc., sterilization markings made by coating paper with a thermochromic composition have been used, for example, as described in Japanese Patent Publication No. 52-2324 and Japanese Patent Application Laid-open No. 61-123682. Sterilization is confirmed by placing paper along with surgical instruments in a sterilizer and detecting the heating temperature, but sterilization display paper is pasted on each can and these are peeled off from the can after sterilization. Since the amount of canned beverages produced is enormous, doing so is not only extremely troublesome, but also increases production costs.

On the other hand, the ink composition for inkjet recording, for example,
As described in JP-A No. 55-115478, inorganic salts such as lithium nitrate and lithium halides are usually included together with an organic solvent and a dye, thereby giving the ink composition the required specific resistance. , usually about 1500
Provides a specific resistance of Ωcm or less.

While the invention is trying to solve this problem, the present inventor conducted intensive research to obtain an ink composition that can be printed using the above-mentioned inkjet recording method and has thermochromic properties in the printing itself, and as a result, as a pigment,
By using a cyanine dye, the resistivity required for an inkjet recording ink composition can be achieved even without the addition of salts as described above, and therefore, it is less corrosive and can be sterilized using normal heat. The present invention was achieved by discovering that it can function as a sterilization indicator with excellent discoloration in the temperature range of .

Therefore, the present invention aims to provide a sterilization indicating ink composition for inkjet recording, which is capable of printing required information on a can body using an inkjet method and at the same time attaching a sterilization indication to the can body.

A first aspect of the sterile indicating ink composition for inkjet recording according to the present invention includes (al: an organic solvent, (bl: a cyanine dye dissolved in the above organic solvent, and fC) a cyanine dye dissolved in the above organic solvent. and a resin having a carboxyl group or a phenolic hydroxyl group.

A second non-concave display ink composition for inkjet recording according to the present invention contains, in addition to the above components, an alkali metal salt dissolved in the organic solvent.

In the ink composition according to the present invention, examples of the organic solvent include alcohols such as methanol, ethanol, propatool, butanol, and cyclohexanol, and alkylene glycol monoalkyl compounds such as ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, and propylene glycol monomethyl ether. ethers,
Polar organic solvents such as alkylene glycol monoesters such as ethylene glycol monoacetate, ketones such as methyl ethyl ketone, methyl isobutyl ketone, isophorone, and cyclohexanone are preferably used. These organic solvents may be used alone or as a mixture of two or more.

However, if the amount of organic solvent in the ink composition is too large, the adhesion of the print to the can body will be poor, or the density of the print will be insufficient.On the other hand, if the amount of organic solvent is too small, the viscosity of the ink composition will be too high. This makes it difficult to print on the can body using an inkjet method. Therefore, in the present invention, these organic solvents are used in the ink composition at 80%
It is blended in a range of 96% to 96% by weight, preferably 85 to 92% by weight.

The cyanine dye used in the present invention is not particularly limited as long as it is soluble in the above organic solvent. Specific examples of such cyanine dyes include C,1, Basic Red 12.13.14.15.27.35.
36.37.45.48.49.52.53.66.6
8 etc. can be mentioned. These cyanine dyes may be used alone or as a mixture of two or more.

In the present invention, the cyanine dye is blended in the ink composition in an amount of 0.2 to 5% by weight, preferably 0.5 to 3% by weight. When the amount is less than 0.2%, the degree of discoloration due to heat is insufficient, and when the amount is more than 51%, the difference in discoloration due to heat is small.

In general, cyanine dyes are expressed in -formula (where Y and Yo are 0, S, Se,... NH, -CH
-CH-, etc., R and Ro represent an alkyl group,
X represents a halogen atom, and n is an integer of 0 to 3. )
It has a quaternary ammonium salt structure.

The reason why the ink composition according to the present invention has the electrical conductivity necessary for inkjet printing even though it does not contain salts is because the cyanine dye has a quaternary ammonium salt structure. It appears to be.

The resin used in the present invention needs to have a carboxyl group or a phenolic hydroxyl group. As mentioned above, canned beverages are usually sterilized by heating in an environment where moisture is present, so in order to fix the printing on the can body and prevent the printing on the can body from bleeding due to moisture. It is.

Examples of resins having carboxyl groups or phenolic hydroxyl groups include rosin resins such as rosin, hydrogenated rosin, rosin esters, rosin-modified maleic acid resins, rosin-modified phenol resins, phenol resins, alkylphenol resins, and phenol resins. type resins are preferably used. The phenolic resin may be either a resol type or a novolac type. Such rosin-based resins and phenol-based resins can be easily manufactured manually as commercial products. For example, examples of the rosin include Rosin H made by Tokushima Oil Co., Ltd. (Kikki), and examples of the phenolic resin include Tamanol 100S made by Arayo Kagaku Kogyo A and Hitachi Chemical Co., Ltd. (Taru made Hitanol 1501).

Furthermore, maleic acid resins and styrene-maleic acid copolymer resins are also suitably used. Such maleic acid resins include, for example, Tokushima essential oil (Kiki Seiki Teskit MRA, MRM-11,
It can be obtained as a commercial product such as MRM-42, MRM-53, and Marquid 33 manufactured by Arayo Kagaku Kogyo ■.Styrene-maleic acid copolymer resin can be obtained, for example, from BAS
It can be obtained as a commercial product such as Spravar AP20 and Spravar AP30 manufactured by Company F.

Such a resin is blended in the ink composition according to the present invention in an amount of 2 to 20% by weight, preferably 3 to 15% by weight. When the amount of resin blended is less than 2% by weight, the adhesive strength of printing on the can body is poor; on the other hand, when it is blended in an excessive amount exceeding 20% by weight, the viscosity of the ink composition is too high. It is difficult to print using the inkjet method.

The ink composition according to the present invention further includes an alkali metal salt based on the ink composition in order to increase its conductivity.
．． It can be contained in a range of 2 to 8% by weight, preferably 0.5 to 5% by weight. Even if an excessive amount of alkali metal salt is blended, it is not preferable because it will not dissolve in the ink composition, making it difficult to print by an inkjet method, and also making the ink composition more corrosive to metals.

In the present invention, the alkali metal salts include, for example, inorganic salts such as lithium bromide, potassium bromide, lithium chloride, sodium chloride, potassium chloride, lithium iodide, potassium iodide, and sodium iodide, or organic acids. Mention may be made of alkali metal salts such as sodium acetate, sodium propionate, potassium butyrate, sodium oleate, sodium benzoate, sodium valmitate, sodium stearate, and the like. Among these, lithium chloride and sodium acetate are particularly preferably used.

The ink composition according to the invention can further contain an organic carboxylic acid. In particular, when the ink composition contains an alkali metal salt of an organic acid, by simultaneously containing such an organic carboxylic acid, undesirable discoloration such as discoloration at room temperature can be effectively suppressed. As the organic carboxylic acid, for example, acetic acid is preferably used, but higher carboxylic acids such as propionic acid, butyric acid, valeric acid, etc., and higher fatty acids other than these can also be used.

Although the method for producing the ink composition according to the present invention is not particularly limited, preferably, for example, an organic solvent and other components are charged into a dissolving pot, and the ink composition is heated at room temperature or as needed at 70°C.
Each component is dissolved in a solvent by heating to an appropriate temperature of about 0°C, and after cooling, insoluble matter is filtered off.

Effects of the Invention The sterile indicating ink composition for inkjet recording according to the present invention contains a cyanine dye as a pigment component, and this appears to be because this dye has a quaternary ammonium salt structure. The sterilization label can be printed on the can at the same time using the inkjet recording method.

EXAMPLES The present invention will be explained below with reference to Examples, but the present invention is not limited to these Examples in any way. The number of parts indicates parts by weight.

Example 1 SWT-Red 4 (c, r, manufactured by Fukadoya Chemical Co., Ltd. 0 Zero Co., Ltd., Basic Red 14 3.0 parts Oil Blue #8 (Chuo Gosei Kagaku Kogyo Co., Ltd. (Kiku-made oil-soluble dye) 0.8 parts Tamanol 100S (rough) Chemical industry (barrel-made alkylphenol resin) 10.0 parts Ethanol 66.2 parts Ethylene glycol monoethyl ether 20.0 parts An ink composition having the above components was prepared.The specific resistance was 1500 Ωcm at 25°C, and the can We were able to print clearly in purple on the can body using the inkjet recording method.The can body was placed in an autoclave with steam under a pressure of 1 kg.
/crA, and was thermally sterilized at a temperature of 121° C. for 20 minutes, and it was confirmed that the print had changed color to blue.

Example 2 Crampons Cachiron Brilliant Scarlet RH Conc (C, 1, Basic Red 37, manufactured by Fukadoya Chemical Industry Co., Ltd.) 2.0 parts Oil Blue #603 (C, 1, Solvent Blue 5, manufactured by Chuo Gosei Chemical Industry Co., Ltd.) ) 1.0 parts Tamanol 100S 5.0 parts Rosin H (Rosin manufactured by Tokushima Oil Co., Ltd.) 5.0 parts Lithium chloride
1.0 part cyclohexanone
25.0 parts ethanol
31.0 parts Ethylene glycol monoethyl ether 22.0 parts Ethylene glycol monobutyl ether 8.0 parts An ink composition having the above components was prepared. The specific resistance was 900 Ωcm at 25° C., and it was possible to clearly print purple color on the can body using an inkjet recording method. This can body is heated with steam in an autoclave at a pressure of 1 kg/cn.
! After heat sterilization at a temperature of 121° C. for 20 minutes, it was confirmed that the printed characters had turned blue.

Example 3 Cramps Brilliant Pink B GH200% (Fukadoya Chemical Industry 01 C, R, Basic Red 27) 4.0
Part Neozapon Blue 807 (C, T, manufactured by BASF, solvent proof 0) 1.0 parts Suprapal AP30 (styrene-maleic acid resin manufactured by BASF) 3.0 parts Rosin H (rosin manufactured by Tokushima Seishin) 2.0 parts Part Ester Gum PE (rosin ester manufactured by Tokushima Oil Co., Ltd.) 4.0 parts Sodium acetate 4.0 parts Ethanol 52.0 parts Ethylene glycol monoethyl ether 25.0 parts Ethylene glycol monobutyl ether 5.0 parts Ink composition having the above components I prepared something. The specific resistance was 1800 Ωcm at 25° C., and it was possible to clearly print purple color on the can body using an inkjet recording method. This can body is heated to a pressure of 1 kg using steam in an autoclave.
/col S'IL When heat sterilized at 121°C for 20 minutes, it was confirmed that the print had changed color to sky blue.

Example 4 Eisen Cachiron Brilliant Pink BH (C, 1, Basic Red 36, manufactured by Fukadoya Chemical Co., Ltd.) 4.0 parts Harifast Yellow 4120 (Solvent Yellow 21, manufactured by Orient Chemical Co., Ltd.) 0.6 1 part Tamanol 510 (alkylphenol resin manufactured by Arayo Kagaku Kogyo ■) 10.0 parts Lithium chloride 1.0 parts Cyclohexanone 10.0 parts Ethanol
44.4 parts Ethylene glycol monoethyl ether 30.0 parts An ink composition having the above bones was prepared. The specific resistance was 900 ΩcI11 at 25° C., and it was possible to print clearly on the can body in red using an inkjet recording method. This can body is heated to a pressure of 1 kg using steam in an autoclave.
/cat was thermally sterilized at a temperature of 121° C. for 20 minutes, and it was confirmed that the printed characters had changed color to yellow-orange.

Patent applicant: Sakura Crepas Co., Ltd.

Claims (2)

[Claims] (1) A sterilization indicator for inkjet recording consisting of (a) an organic solvent, (b) a cyanine dye dissolved in the organic solvent, and (c) a resin having a carboxyl group or a phenolic hydroxyl group dissolved in the organic solvent. Ink composition. (2) (a) an organic solvent, (b) a cyanine dye dissolved in the above organic solvent, (c) a resin having a carboxyl group or a phenolic hydroxyl group dissolved in the above organic solvent, and (d) a cyanine dye dissolved in the above organic solvent. A sterile indicating ink composition for inkjet recording comprising a dissolved alkali metal salt.