JP2014198836A - Method of manufacturing printed egg shell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inkjet ink for egg shell printing high in print density and discriminability on a surface of an egg shell, excellent in safety, and having no elution or color permeation into albumen during producing a boiled egg.SOLUTION: There is provided a method of manufacturing a printed egg shell, including a fist step of extracting kaoliang pigment, rosewood pigment, turmeric pigment, bixin, or annatto pigment from a rough pigment containing kaoliang pigment, rosewood pigment, turmeric pigment, bixin, or annatto pigment by a mixed solvent containing ethanol of 75 to 85 wt.% and water of 15 to 25 wt.% based on the total solvent, a second step of manufacturing an inkjet ink comprising ethanol of 60 to 69 wt.%, water of 15 to 23 wt.%, a pigment obtained in the first step of 1 to 9 wt.%, and a shellac resin of 4 to 8 wt.% based on the total ink, and a third step of printing the egg shell by an inkjet ink manufactured in the second step.

Description

  The present invention relates to an inkjet ink that is suitably printed on an eggshell, and an eggshell printed therewith.

For foods such as unprocessed foods, display of the production area, producer display, production history, etc. is required, and for processed foods, display of the expiration date etc. is required. Clarification of production history, harvest date, expiration date, etc. is becoming popular as a method for improving quality, confirming safety, reliability of products, and providing a sense of security.
These indications are for raw foods, processed foods and other objects directly, through packaging materials, etc., materials that come into contact with food, or materials that pass through the environment where food is handled. However, it is preferable that each product is printed with ink in consideration of safety.

Conventionally, printing of numerical values and the like using a printing press has been performed, but rapid variable information marking cannot be performed by a method using a printing press.
On the other hand, ink jet printers and thermal transfer printers are conventionally used to record production dates and lot numbers on canned foods and packs. Since these printers can directly record variable information, there is no need to create a printing plate, information can be easily changed by a computer, and various applications have been developed at production sites.

In particular, ink jet printers are used in a very wide range because they can perform printing at high speed and only require a small amount of ink by ejecting the necessary ink. In addition, since printing can be performed without contact, it is also suitable for marking on curved surfaces or soft objects.
As an ink used for an ink jet printer, there is one obtained by dissolving a water-soluble dye, which is a food additive colorant, in water, but its water resistance is inferior, and it cannot be used for an object in contact with water. Moreover, it is preferable from the viewpoint of hygiene that the ink used for marking on foods, food-related materials, food packaging materials and the like is an ink according to food. For this reason, ethanol has attracted attention as an ink solvent.

  As an ink-jet ink excellent in water resistance and suitable for printing on the surface of food, Patent Document 1 (Japanese Patent Laid-Open No. 53-127010) discloses that the binder is shellac, a solvent comprising water and ethanol, and iron chlorophyllin sodium. Or (and) a green ink composition containing copper chlorophyllin sodium as a colorant is disclosed.

  Patent Document 2 (Japanese Patent Application Laid-Open No. 2000-191969) discloses iron chlorophyllin sodium and / or copper chlorophyllin sodium, an alkali metal salt of alginic acid and / or propylene glycol alginate, propylene glycol and / or glycerin, and water. The marking method to eggshell characterized by marking the inkjet ink containing by the inkjet system is proposed.

  Patent Document 3 (Japanese Patent Application Laid-Open No. 2006-261061) discloses ethanol 70 to 91% by weight, colorant 1 to 13% by weight, which is an ethanol-soluble quorian dye or titan dye, shellac resin 4 to 8% by weight, sodium lactate 0. Marking on egg surface by inkjet method using 5 to 3% by weight, acetic acid, propionic acid or lactic acid 0.5 to 5% by weight, propylene glycol 0 to 5% by weight and water 2 to 10% by weight And manufacturing a marked egg, including a step of supplying warm air to the egg surface, and a step of applying warm air to the marking surface so that the temperature of the warm air is 25 to 80 ° C. A method is disclosed.

Japanese Patent Laid-Open No. 53-127010 JP 2000-191969 A JP 2006-261061 A

  However, the colorant such as copper chlorophyllin used in the invention described in Cited Document 1 is not a water-soluble pigment but sufficiently soluble in ethanol, and in order to increase the ink concentration, The use of is essential. Therefore, this ink is essentially composed mainly of water and is used by mixing a small amount of ethanol. The shellac resin is also of a type that is soluble in water, and in order to stabilize the dissolution, a non-food additive such as morpholine is used as the ink raw material. Further, in order to maintain the solubility of the resin, a solvent such as methyl cellosolve has been used in combination. This was a material that was not allowed in food additives.

Moreover, the ink-jet ink described in the cited document 2 uses iron chlorophyllin sodium and copper chlorophyllin sodium, which are water-soluble dyes having a strong affinity for the eggshell surface, as coloring materials. It was used and was not an ink considering its solubility in ethanol.
Ink-jet inks containing a large amount of water are less dry than ethanol-based ink-jet inks, and the productivity of printed eggshells is poor. In particular, red eggshells are less permeable to ink than white eggs, so it is important to use inks with excellent drying properties from the viewpoint of productivity.

  Since the ink-jet ink described in Patent Document 3 contains 70 to 91% by weight of ethanol, a good printed matter can be expected in terms of dryness and water resistance. However, if the warm air is used without being supplied to the egg surface, the spread of ink on the egg shell surface is large, and further improvement is required from the viewpoint of print quality. In particular, improvement in the visibility of printing on the red eggshell has become an important issue.

  An object of the present invention is to provide a printed eggshell in which ink does not spread easily on the eggshell surface, particularly on the surface of the red eggshell, and whether the warm air is supplied to the egg surface or not, and is excellent in visibility.

As a result of intensive studies to solve the above-mentioned conventional problems, the present inventors have adjusted the solvent concentration in the ink composition to 60 to 69% by weight of ethanol and 15 to 23% by weight of water, and It has been found that when an edible pigment is extracted from a mixture of ethanol and water having a specific composition, an inkjet ink that specifically solves all of the above problems is obtained.
That is, the present invention is a mixed solvent containing 75 to 85% by weight of ethanol and 15 to 25% by weight of water with respect to the total solvent, and moreover than a crude dye containing a quyan dye, a rosen dye, a turmeric dye, a bixin, or an anato dye. , Kolyan dye, rosewood dye, turmeric dye, bixin, or annatto dye extracted from the first step, ethanol 60-69 wt%, water 15-23 wt%, based on the first ink, obtained in the first step A second step for producing an inkjet ink comprising 1 to 9% by weight of a dye and 4 to 8% by weight of a shellac resin;
The present invention relates to a method for producing a printed eggshell including a third step of printing the ink-jet ink produced in the second step on the eggshell.

Further, the present invention relates to one or more kinds selected from the group consisting of 60 to 69% by weight of ethanol, 15 to 23% by weight of water, scoyl dye, rosewood dye, turmeric dye, bixin, and anato dye based on the whole ink. An ink-jet ink for eggshell comprising 1 to 9% by weight of a dye and 4 to 8% by weight of shellac resin,
The dye is a mixed solvent containing 75 to 85% by weight of ethanol and 15 to 25% by weight of water with respect to the whole solvent, and moreover than the crude dye containing a quyan dye, a titan dye, a turmeric dye, a bixin, or an anato dye. The present invention relates to the above-described ink jet ink for eggshell, which is obtained by extracting a pigment, a rose pigment, a turmeric pigment, a bixin, or an anato pigment.

  Further, in the present invention, when the dye is diluted and measured so that the OD (optical density) value of 450 nm is 1.5, the minimum value of 400 to 487 nm is set as the valley OD value. The present invention relates to the above-described ink jet ink for eggshell, wherein the peak OD value / valley OD value is 1.03 or more when a maximum value of ˜520 nm is defined as a peak OD value.

  Moreover, this invention relates to the eggshell printed with the said inkjet ink for eggshells.

  According to the present invention, it is now possible to provide a printed eggshell that is hard to spread ink on the eggshell surface, particularly the red egg shell surface, with high optical density and excellent visibility, regardless of whether warm air is supplied to the egg surface. .

Example 1 ink printing egg Printing egg of ink of Comparative Example 3

The inkjet ink used in the present invention is selected from the group consisting of 60 to 69% by weight ethanol, 15 to 23% by weight water, 15% to 23% by weight of ethanol, a dye of kolyan, a dye of chitan, a turmeric dye, a bixin, and an anato dye. An ink-jet ink for eggshell comprising 1 to 9% by weight of more than one type of dye and 4 to 8% by weight of shellac resin.
The reason why the solvent concentration in the ink composition of the present invention is 60 to 69% by weight of ethanol and 15 to 23% by weight of water is in consideration of defoaming of ink, dot gain of landing ink droplets, and solubility of shellac resin. This is what was considered.

By using 60% by weight or more of ethanol in the ink composition of the present invention, when used in a continuous type ink jet printer, generation of bubbles can be suppressed / prevented, and stable droplet formation can be achieved. Can be operated continuously. Even in the case of an on-demand type ink jet printer, the generation of bubbles can be similarly suppressed / prevented, so that the discharge state is stabilized.
On the other hand, by setting the ethanol concentration to 69% or less, the surface tension of the ink can be increased, and the contact angle between the eggshell surface and the landing ink droplet is increased, so that dot bleeding is less likely to occur and high-density, high-definition printing is possible. Become.

  In the case of 15% by weight or more of water in the ink composition of the present invention, if the solid content is the same, ethanol is relatively reduced and dot bleeding can be suppressed / prevented. On the other hand, when the water content is 23% by weight or less, the solubility of the shellac resin can be improved, and the dischargeability is excellent.

  The food color used in the present invention is a food color extracted from a crude color such as a plant, powder or oily preparation, extracted with a mixed solvent of ethanol and water consisting of 75 to 85% by weight of ethanol and 15 to 25% by weight of water. The dye to be processed. It is only necessary to contain culyan pigment, rosewood pigment, turmeric pigment, bixin, or annatto pigment, and the crude pigment is a synthetic colorant, Food Red No. 2, Food Red No. 3, Food Red No. 40, Food Red No. 102 Food Red 104, Food Red 105, Food Red 106, Food Yellow 4, Food Yellow 5, Food Green 3, Food Blue 1, Food Blue 2, Norbixin Sodium, Norbixin Potassium , A mixture containing bixin, a natural colorant, cucurian dye, rosewood dye, turmeric dye, cochineal dye, lac dye, anato dye, and the like.

  Since the coloring matter used in the present invention is extracted with a solvent mainly composed of ethanol, it has a property having resistance to water. The pigment is preferably contained in the ink in the range of 1 to 9% by weight of the total ink. By using an ink having a pigment content of 1% by weight or more, a printed matter having a high printing density can be obtained, and the discrimination (visibility) is excellent. On the other hand, when the pigment content is 9% by weight or less, it is possible to obtain an ink that has good solubility, hardly increases the viscosity, and has excellent continuous ejection stability.

Synthetic tar-based colorants are often highly soluble in water, and even when ethanol is used as the main extraction solvent, resistance to water may be low. It is desirable to use only natural colorants because of the recent tendency to prefer natural colorants.
Natural colorants also differ in solubility in a mixed solvent of ethanol and water depending on the type, and Kolyan dyes, rosewood dyes, and the like are more suitable colorants because they can have high colorants due to their high solubility.

In the extraction with an ethanol solvent alone, the extracted pigment component is slightly different from the component of the mixed solvent of ethanol and water, and there are differences in color tone, color developability, and eggshell fixability.
In particular, in the case of Koryan dye, a dye having high reddish color density extracted from a mixed solvent of ethanol and water has a maximum value (peak) near the spectral absorption of 487 nm and a minimum value (valley) between 400 nm and 486 nm. And peak O.D. D. Value / valley O.D. D. The value is 1.03 or more, and in printing on the red egg shell, the hue becomes extremely effective in terms of visibility.

The shellac resin used in the present invention is preferably an ethanol-soluble resin. This shellac resin is compatible with the dye used in the present invention. Further, it has a function of increasing the viscosity of the ink by dissolving in ethanol, and functions as a good binder for eggshell as a printing medium.
In the present invention, the shellac resin is preferably contained in the ink in an amount of 4 to 8% by weight of the total ink. By setting the content to 4% by weight or less, an ink having an appropriate viscosity can be obtained, and the adhesion to eggshell is also excellent. Further, when the content is 8% by weight or less, the viscosity of the ink can be lowered moderately, and stable and continuous operation can be performed even at a low temperature.
Shellac resin has a property of being precipitated in water. As the concentration of the shellac resin in the ink increases, the water concentration that causes the shellac resin to precipitate decreases. The content of the shellac resin in the ink is preferably included in the range of 4 to 8% by weight from the viewpoint of suppressing and preventing the precipitation of the shellac resin.

  For the ink-jet ink used in the present invention, a food additive having an arbitrary ion dissociation property can be selected as a conductivity adjusting agent to be suitably used in a continuous type printer. Preferably sodium lactate is used. Sodium lactate is known to provide good solubility and conductivity in ethanol. Sodium lactate is preferably blended in the ink in an amount of 0.5 to 3% by weight of the total ink. When the content is 0.5% by weight or more, the electrical conductivity becomes better, and the content is preferably 3% by weight or less from the viewpoint of improving the cleaning property when replacing the ink.

  In the ink-jet ink used in the present invention, propylene glycol and glycerin can be appropriately used as a moisturizing agent in order to prevent drying of the ink nozzle. These humectants are preferably contained in the ink in the range of 0 to 5% by weight of the total ink. The use of a humectant causes a decrease in dryness of the eggshell that is the printing medium, but it is effective in improving adhesion and adjusting the appropriate solubility of the resin, the dye, and the electrolyte. Although effective for suppressing drying at the nozzle, the marking surface of the eggshell, which is the substrate to be printed, can be quickly dried and the production speed can be expected to be improved. Dirt can be suppressed and prevented.

  In addition, the ink-jet ink used in the present invention may contain a plurality of edible dyes in the ink in order to adjust the color. Like these main dyes, these additive-adjusting dyes are dyes extracted with a mixed solvent of ethanol and water consisting of 75 to 85% by weight of ethanol and 15 to 25% by weight of water.

The inkjet ink used in the present invention is prepared, for example, as follows.
From the edible ancestor pigment, the pigment is extracted with a mixed solvent of ethanol and water consisting of 75 to 85% by weight of ethanol and 15 to 25% by weight of water, and used in the form of a pigment solution separated by filtration. Shellac resin is also used as a solution that has been previously dissolved in ethanol. Further, as the conductivity adjusting agent, an aqueous solution previously dissolved in water is used. An ink-jet ink used in the present invention can be produced by adding a dye solution, a shellac resin solution, a conductivity adjusting agent, a humectant, water and the like, mixing and stirring, and then filtering with a filter having a pore size of 10 μm or less. . Mixing and stirring can be carried out by a high-speed disperser or emulsifier in addition to a stirrer equipped with a normal blade.

The viscosity at 25 ° C. of the ink-jet ink used in the present invention is preferably adjusted to a range of 2 to 10 cps. If the viscosity is too low, the formation of ink dots on the printing medium will be poor, and the print density will be low. On the other hand, if the viscosity is too high, there will be problems with poor ejection and poor drying.
From the viewpoint of viscosity and ejection stability, the solid content in the ink is preferably 10 to 20% by weight.

  The surface tension is adjusted to a range of 20 to 30 mN / m from the mixed solvent ratio of ethanol and water, although there is an influence of other additives. When the ink exhibits a surface tension of generally less than 25 mN / m, the dot gain increases and the print density tends to decrease. Moreover, when marking with a continuous type printer, it is preferable to adjust the electric conductivity of the ink in the range of 0.5 to 2 mS / cm. In addition, the pH of the inkjet ink is preferably 5.0 to 6.8.

  When marking the egg surface using the inkjet ink of the present invention on the egg surface, the marking is performed by marking by an inkjet method, and a marked egg is obtained. Inkjet methods include continuous methods (multi-value deflection, binary deflection), drop-on-demand methods (Bubble Jet (registered trademark) method, piezo method, solenoid valve method, etc.), etc., but marking at high speed For the marking of curved surfaces such as eggs and soft surfaces, the continuous method is suitable.

In the present invention, the print surface may be dried by air drying before and after printing.
It is desirable to adjust the supply of the air flow at this time so that the airflow is applied simultaneously with the marking or within 0.5 seconds. As a result, the spread of the printing dots and the drying speed are controlled, and good printing is formed even for minute condensation on the surface of an egg or the like.

Eggs to be marked are not limited to chickens and quails, but can also be applied to research birds and reptile eggs.
The data to be marked can be written together with the production location, harvest date and time, producer, date, special symbols, and the like.
For eggs and the like, if marking is performed in conjunction with data such as size and egg collection information, quality can be presented to the consumer, resulting in a high-value-added product.
These notations give reliability to the distribution form of the product as a reliable display method of the route.

Hereinafter, the present invention will be described in detail with reference to examples. In the examples, parts and% indicate parts by weight and% by weight, respectively.
Example 1
In the first step, 25 parts of Kolyan pigment, 60 parts of ethanol, and 15 parts of water (ethanol: water = 80: 20), a total of 100 parts, are stirred and mixed. The obtained mixed solution is filtered through a filter paper having a pore diameter of 1 μm to obtain a cuolian dye extract B. At this time, the concentration of non-volatile solids in the cucumber dye extract was 15%.
Subsequently, in the second step, 60 parts of the collan dye extract B, 10 parts of shellac resin solution, 5 parts of sodium lactate solution, 15 parts of ethanol, and 10 parts of water are mixed with stirring. The obtained mixed solution was filtered with a filter paper having a pore size of 1 μm, and lignite pigment: 9% by weight, shellac resin: 5% by weight, sodium lactate: 2.5% by weight, ethanol: 60.8% by weight, water: 22.7 A weight percent inkjet ink was obtained.
The shellac resin solution is a 50% ethanol solution, and the sodium lactate solution is a 50% aqueous solution.

(Examples 2-7 and Comparative Examples 1-5)
An inkjet ink was prepared in the same manner as in Example 1 except that the raw materials shown in Table 1 were used.

The inks obtained in Examples and Comparative Examples were measured for viscosity (mPa · s), surface tension (mN / m) and electrical conductivity (mS / cm) at 25 ° C.
The viscosity is measured using a viscometer (“RB80L” manufactured by Toki Sangyo Co., Ltd.), and the surface tension is measured using a surface tension meter (“Surface Tensiometer” manufactured by KYOWA INTERFACE). Was measured using a conductivity meter ("C66 type conductivity meter" manufactured by Milwaukee Japan).

  Further, the stability with time of the ink stored at 25 ° C. for 1 month was evaluated by visually confirming the precipitation. ○ indicates that no precipitation was observed at the bottom of the ink container, and X indicates that precipitation was observed at the bottom of the ink container.

The inks obtained in the examples and comparative examples were placed in an ink tank of a continuous type ink jet printer and marked on the eggshell, which is a printing medium, without applying hot air, and the ejection stability and the like were evaluated.
<Discharge stability>
○: Can be printed after circulating the filled ink ×: Cannot be printed due to agglomeration of the dilution shock in the tank, clogging of the circulation filter, ejection failure, etc. <Print density>
○: Identifiable ×: Not identifiable <dot sharp> (smear) (Evaluates the form of character dots printed on red eggs)
○: The dot diameter is sharp ×: The dot diameter blurs <water resistance> (observation evaluation of the printed part of the boiled egg for 10 minutes after printing)
○: Characters in the printed part can be identified ×: Characters in the printed part cannot be identified

  About the ink (Examples 1-3, Comparative Examples 1-5) which used the Kolyan pigment | dye as an edible pigment | dye, it diluted so that OD value of 450 nm might be set to 1.5 using 99 degree fermentation ethanol, and spectroscopy The absorption wavelength was measured with a photometer. From the obtained OD spectrum (spectral spectrum), a peak is detected near the spectral absorption of 487 nm, and a valley is detected between 400 nm and 486 nm. D. Value / valley O.D. D. The value was calculated.

As shown in Examples 1 to 7, the ink-jet ink for eggshell of the present invention is excellent in aging / ejection stability and water resistance.
On the other hand, in Comparative Example 1 in which the pigment was extracted from the primary pigment with a mixed solvent of ethanol: water 75:25 and the amount of water in the ink was large, the dissolution / filterability was poor and the ejection test could not be performed.
Further, even when the same extract as the dye extract used in Example 1 was used, Comparative Example 2 with a large amount of water in the ink had the same result as Comparative Example 1, and the amount of ethanol in the ink was large. As shown in Comparative Example 3, the character dots printed on the red chicken eggs are blurred. The printed matter in the case of Example 1 is shown in FIG. 1, and the printed matter in the case of Comparative Example 1 is shown in FIG. In the case of FIG. 1, it can be seen that dot formation with less blur is clearly formed, and it is easy to identify with high print density.
Comparative Examples 4 and 5 are cases where there is a large amount of ethanol at the time of pigment extraction, and character dots bleed on the red egg shell as in Comparative Example 3.

Claims (4)

It is a mixed solvent containing 75 to 85% by weight of ethanol and 15 to 25% by weight of water with respect to the whole solvent, and moreover than a crude dye containing a cucumber dye, a tan dye, a turmeric dye, a bixin, or an anato dye, , Turmeric dye, bixin, or anato dye, and 60 to 69 wt% ethanol, 15 to 23 wt% water, and 1 to 9 wt% dye obtained in the first step with respect to the total ink A second step for producing an inkjet ink comprising 4 to 8% by weight of shellac resin,
A method for producing a printed eggshell, comprising a third step of printing the ink-jet ink produced in the second step on the eggshell.   1 to 9% by weight of one or more pigments selected from the group consisting of 60 to 69% by weight of ethanol, 15 to 23% by weight of water, scoyl pigment, rosewood pigment, turmeric pigment, bixin, and anato pigment based on the total ink Inkjet ink for eggshell comprising 4 to 8% by weight of shellac resin, wherein the dye is a mixed solvent containing 75 to 85% by weight of ethanol and 15 to 25% by weight of water with respect to the whole solvent, An ink-jet ink for eggshells, which is obtained by extracting a wolfberry dye, a rosen dye, a turmeric dye, a bixin, or an anato dye from a crude dye containing a tannin dye, a turmeric dye, a bixin or an anato dye.   When the dye was diluted so that the OD (optical density) value of 450 nm was 1.5, the minimum value of 400 to 487 nm was defined as the valley OD value, and the maximum value of 450 to 520 nm was determined. The ink jet ink for eggshell according to claim 2, wherein the peak OD value / valley OD value is 1.03 or more when the peak OD value is used.   An eggshell printed with the ink-jet ink for eggshell according to claim 2 or 3.

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