KR100457731B1 - Black ink composition for digital stencil printing - Google Patents

Abstract

The present invention relates to a dark blue ink composition for digital light use, and more particularly, in a water-in-oil (W / O) type emulsified digital ink composition composed of 20 to 80% of oil phase and 80 to 20% of water phase. In addition, the oil-soluble component is composed of 3-15% fat-soluble resin made of long whey alkyd resin, 2-15% fat-soluble colorant made of carbon black, which is an inorganic pigment, and polyoxyethylene having an HLB value of 3-10. 1 to 20% of emulsifier mixed with stearic amine derivative and sorbitan monooleate at a constant ratio, 3 to 15% of volatile solvent as a non-Romatic component, and 5 to 20 of nonvolatile solvent which is liquid paraffin % To 1% by weight of hydroxypropyl cellulose in the composition ratio of the aqueous phase component, and 5% to 15% by weight of water-soluble colorant which is a dark blue ultrafine raw material having a diameter of less than 1 µm. Wetting agent is 3 to 10%, It is a dark blue ink composition for use in digital lamps, which adds 40-77% of ion-exchanged water to solubilize water, and has excellent storage and stability, good separation of paper from ink drums during printing, and There is no retina, there is an advantage that does not cause trouble even when left in the printing machine. In addition, by using the black and white ink composition of the present invention, it is effective to obtain a printed material having a high printing density, high bleeding property, no blurring, no staining, and clear color.

Description

Black ink composition for digital stencil printing

The present invention relates to a dark-color ink composition for digital isoprinting, and more particularly, to an oil phase containing a fat-soluble resin, a fat-soluble colorant, an emulsifier, a volatile solvent and a nonvolatile solvent, a water-soluble resin, a water-soluble colorant, a humectant, and water. It is characterized by consisting of the water.

Digital copy printing is a stencil printing method, which forms an opening in an image portion of an original, passes ink through the opening, and prints on the surface of the printed object. In the conventional case, an impact method, a friction method, and an electrical Since the openings were formed on the base paper by using an energy method, the openings were relatively small, and each of them had to use a less viscous or fluid ink to pass through the openings. It was not good and it was difficult to get high quality prints.

In recent years, the thermal print head method can be used to heat the paper and form a relatively large opening, thereby making it possible to use a water-in-oil emulsion ink having a viscosity.

Water-in-oil emulsion ink is emulsion of oil phase and water phase. Generally, pigment particle and water particle are dispersed in micro phase in oil, which is a dispersion medium, and it is easy to separate oil from ink and cause oil bleeding on printed matter. Easy to let In addition, it is difficult to preserve the initial quality of the emulsion ink for a long time, and especially in a high temperature environment (50 to 70 ° C.), the aggregation of pigment particles in the dispersoid and the aggregation of water phase particles are accelerated, and the initial quality is extremely maintained. There was a difficult problem.

In addition, when the water-insoluble colorant is contained in the oil phase of the emulsion ink, the oil phase first penetrates into the to-be-printed object, and the water-insoluble colorant rises thereon, which takes time to penetrate and dry the ink and causes bleeding of the ink. In addition, since the ink component penetrates to the deeper portion of the printed object, there is a problem that the printing density is lowered and the back non-penetration tends to occur.

In addition, since the ink component does not remain on the surface of the printed object at a high rate of penetration of the ink component into the printed object, the ink component penetrates into the printed object, reducing the printing density of the print and increasing the exudation of the ink. Backing is reduced because it does not remain on the surface of the printed material. On the other hand, when ink penetrates slowly, the ink component tends to remain on the surface of the printed object, and the printing density on the print is increased and the exudation is reduced, but the ink component remains in a large amount on the surface of the printed object, thereby increasing the backing of the ink.

In order to solve the above problems, domestic patent registration No. 10-0196955 proposed an emulsion ink which is not affected by the ink penetration rate by adding an extender pigment, but after the oil phase has penetrated the water phase. Therefore, even when the extender pigment is included in the water phase, it has been found that the penetration rate and drying characteristics of the ink cannot be improved. In addition, Japanese Patent Application Laid-open No. Hei 8-245915 discloses an emulsion for stencil printing using a reversible thermosensitive polymer compound. However, this is a method of changing the physical properties of the ink by adding a wax and a reversible thermosensitive high-molecular compound, so that the viscoelasticity of the ink is not maintained by the phase stability of the emulsion itself, it is forced to the ink through the addition of additives By providing viscosity, it is possible to prevent print stability and leakage of ink. It is expected, but the wax or gamonseong storage stability due to the viscosity change of ink according to the temperature, so that dependent on the physical properties of the polymer will be lower.

In addition, in Korean Patent Registration No. 10-0196978, tertiary amine mixture was added to the aqueous phase to prevent separation of the oil phase and the aqueous phase and to improve the shelf life of the emulsion ink, but the bleeding property of the emulsion ink was not good, and in Korean Patent Publication No. 1999-0073354 Emulsion ink was prepared by mixing various compositions of oil phase and water phase to prevent bleeding and spreading of printed matter, but the temperature stability and storage stability of the ink were not taken into consideration, making it difficult to store for a long time.

In addition, the domestic patent registration number 0185529 is an environmentally friendly, and suggests an ink composition for use in digital rotation, such as excellent back staining, back non-permeability, etc., but the storage of the ink is pointed out as a problem due to the composition, such as ethylene glycol.

Therefore, the present invention, in order to solve the problems with the conventional ink composition, an oil phase including a fat-soluble resin, a fat-soluble colorant, an emulsifier, a volatile solvent and a non-volatile solvent and an aqueous phase containing a water-soluble resin, a water-soluble colorant, a wetting agent and water. The purpose of this invention is to provide a clear print without smearing, smearing, or backing, and at the same time, to provide an excellent digital light-color ink composition that does not collapse the emulsion according to temperature and duration during storage. .

In order to achieve the above object, the present invention provides a water-soluble resin, a water-soluble colorant, a wetting agent, and water 20-80% by weight containing an oil-soluble resin, a fat-soluble colorant, an emulsifier, a volatile solvent and a nonvolatile solvent. The present invention provides a dark blue ink composition for digital light use, comprising 20% by weight. When less than 20% by weight based on the oil phase, the storage stability is poor due to unstable phase when preparing water-in-oil (W / O) emulsion ink, and 80 When the weight percentage is exceeded, the ink viscosity decreases and the weather stability in the printing machine is reduced.

The blending ratios described below are based on 100% by weight of a dark blue ink composition for digital light use.

As the fat-soluble resin contained in the oil phase in the present invention, rosin-modified phenolic resins, long whey alkyd resins, petroleum resins, and the like are used, and a blending ratio of 3 to 15% by weight is appropriate. If the fat-soluble resin is less than 3% by weight, the ink viscosity is weak and adhesion to the paper to be printed is poor, and the friction resistance is poor. When the fat-soluble resin is more than 15% by weight, the dryness is slowed, the backing resistance is poor, and the heat resistance is poor.

Inorganic pigments, such as carbon black, are used as a fat-soluble colorant, The compounding ratio shall be 2-15 weight%. If the colorant is less than 2% by weight, the concentration of the ink composition is low. If the colorant is more than 15% by weight, the dispersibility of the ink composition is inferior, and the particles of the ink composition become larger, which causes the emulsion to collapse, and also causes screen retardation during printing.

As the emulsifier, a polyoxyethylene stearic amine derivative having a HLB (hydrophile-lipophile-balance) value of about 3 to 10 and a sorbitan monooleate are mixed in a ratio of about 1: 1, and the mixing ratio is 1 to 20. It is suitable to make it by weight%. If the HLB value is less than 3, the lipophilic property becomes strong, and if it exceeds 10, the hydrophilic property becomes strong, and the function as an emulsifier is weakened, making it difficult to emulsify the oil phase and the water phase. In addition, when the emulsifier is less than 1% by weight, it is difficult to form an emulsion, and when it exceeds 20% by weight, the viscosity becomes high, making it difficult to supply ink on a printing press.

Volatile solvents vary in dryness and storage stability of the ink depending on the volatilization temperature range. Therefore, an aromatic free type solvent having an appropriate volatilization temperature is used, and the blending ratio is 3 to 15 weight. %. The use of an aromatic volatile solvent not only brings about a phase change by volatilization of the aromatic component over time, but also a change in the concentration and drying of the ink. The aromatic component is harmful to the human body and has a bad smell. It is preferable not to. If the volatile solvent that does not contain an aromatic component is less than 3% by weight, the drying may be slow, causing backing problems. If the content of the volatile solvent exceeds 15% by weight, the emulsion phase formation becomes unstable and the emulsion collapses, resulting in retinal contamination and contamination of the print head. It can be cause.

As a nonvolatile solvent, liquid paraffin-based mineral oil is used, and the mixing ratio thereof is 5 to 20% by weight. The use of vegetable oil such as linseed oil as a non-volatile solvent causes the ink to oxidize and dry, causing a problem of film formation.If the mineral oil is less than 5% by weight, the film's dryness becomes faster, resulting in damage during reprinting and screen retina. If it exceeds 20% by weight, the drying property is delayed, causing backing.

As the water-soluble resin contained in the water phase, cellulose-based water-soluble resins such as ethyl cellulose, carboxyl cellulose and hydroxy propyl cellulose are used, and the blending ratio is 1 to 10% by weight. If the water-soluble resin is less than 1% by weight, the viscosity of the ink composition is lowered and spreading occurs. If the water-soluble resin is more than 10% by weight, the film drying property is increased, which causes a problem of retinal screens during printing.

As a water-soluble colorant, a dark blue ultrafine raw material (jet base) is used, and the blending ratio is 5 to 15% by weight. If the water-soluble colorant is less than 5% by weight can not be obtained thick prints, when the water-soluble colorant exceeds 15% by weight can be reflected back. Since the water-insoluble pigment is contained in the aqueous phase, it is possible to obtain a printed product with a high concentration, and also to make it possible to disperse the particles of the ink composition to 1 占 퐉 or less, so that the storage composition of the ink composition is excellent.

As the humectant, glycerin, which can have not only a wetting effect but also a freezing effect, is used, and its blending ratio is 3 to 10% by weight. If the wetting agent is less than 3% by weight, the wetting effect and the freeze-preventing effect are less. If the wetting agent is more than 10% by weight, the storage stability of the ink composition may be impaired. Add water and use. The use of ion-exchanged water can provide a more stable emulsion-like ink composition, and can prevent phase separation and emulsion collapse of the ink by impurities contained in water.

In order to impart various functionalities of the ink composition to the water phase, a preservative, a transfer force improving agent, a rust preventive agent, an antifoaming agent, or the like may be added.

Hereinafter, the present invention will be described in detail as Examples and Comparative Examples. However, the present invention is not limited to the following.

Example 1

According to the blending ratio shown in Table 1 to prepare a dark blue ink composition for digital use. Enteric whey alkyd resin as fat-soluble resin, carbon black as fat-soluble colorant, sorbitan monooleate and stearic amine derivative as emulsifier, D110 solvent as parasol and non-volatile solvent as paraffin oil, are stirred and mixed with three roll mills. Prepare an oil phase. After dissolving hydroxy propyl cellulose, which is a water-soluble resin, in ion-exchanged water, a dark-colored ultrafine raw material (jet base), which is a water-soluble colorant, and glycerin, which is a humectant, are added, followed by sufficiently stirring and mixing to prepare an aqueous phase. The prepared aqueous phase is emulsified with a stirrer while gradually adding the oil phase to prepare a dark colored ink composition for digital lamp use.

Example 2

According to the mixing ratios shown in Table 1, enter the whey alkyd resin, rosin-modified phenolic resin, D110 solvent and paraffin oil, and dissolved by heating and cooling, and then sorbitan monooleate and polyoxyethylene stearic amine derivative by stirring and mixing Then, by rolling three roll mill to prepare an oil phase. After dissolving hydroxy propyl cellulose in ion-exchanged water by heating, a dark blue ultrafine raw material and glycerin were added thereto, followed by sufficiently stirring and mixing to prepare an aqueous phase. The prepared aqueous phase is emulsified with a stirrer while gradually adding the oil phase to prepare a dark colored ink composition for digital lamp use.

Example 3

According to the blending ratios shown in Table 1 below, the process of Example 1 was used to prepare a dark blue ink composition.

(Comparative Example 1)

Instead of the mixture of oily sorbitan monooleate and stearic amine derivative, the sorbitan monooleate was added in the digital isochrome ink composition of Example 1, and the remainder was the same as in Example 1. A dark colored ink composition is prepared for use in digital lighting.

(Comparative Example 2)

In the digital equivalent black ink composition of Example 1, a motor oil was added in place of the oily paraffin oil, and the remainder was the same to prepare a digital white ink ink composition using the same process as in Example 1.

(Comparative Example 3)

In the digital isochrome ink composition of Example 1, only the hydroxy propyl cellulose of the aqueous phase was not added, and the remainder was the same to prepare a digital isochrome ink composition in the same manner as in Example 1.

(Comparative Example 4)

In the aqueous phase of Example 1, only the dark blue ultrafine raw materials were added, and the remainder was the same, to prepare a digital light-colored dark ink composition in the same manner as in Example 1.

(Comparative Example 5)

Ethylene glycol was added in place of glycerin in the aqueous phase of Example 1, and the remainder was the same to prepare a dark blue ink composition for digital light use in the same manner as in Example 1.

Mixing ratio of black ink composition for digital light use (unit: weight%) Ink formulation Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Oily ingredient Fat-soluble resin Whey Alkyd Resin 5 3 5 5 5 5 5 5 Rosin Modified Phenolic Resin - 2 - - - - - - coloring agent Carbon black 5 5 5 5 5 5 5 5 Emulsifier Sorbitan monooleate 2 2 2 4 2 2 2 2 Stearic amine derivatives 2 2 2 - 2 2 2 2 Volatile Solvents YK D-110 ¹⁾ 5 5 5 5 5 5 5 5 Nonvolatile Solvent Paraffin oil 10 10 10 10 - 10 10 10 Motor oil - - - - 10 - - - Water component Water soluble resin Hydroxypropyl cellulose 3 2 3 3 3 - 3 3 Water Soluble Coloring Agent Ink color ultra fine raw materials (jet base) 10 10 5 10 10 10 - 10 Humectant glycerin 5 5 5 5 5 5 5 - Ethylene glycol - - - - - - - 5 water Ion exchange water 53 54 58 53 53 56 63 53

Note 1) Model number of domestic S K company

The test results of the digital light-used black ink compositions prepared through the examples and the comparative examples are shown in Table 2 below.

Test results of digital black ink compositions prepared through Examples and Comparative Examples Ink Test Results Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Print density 1.96 1.94 1.65 1.89 1.85 1.90 1.35 1.97 Non-invasive 0.02 0.02 0.02 0.03 0.02 0.03 0.01 0.03 Smearing Friction resistance Storage stability Temperature stability dry Back voice

Assessment Methods : Satisfied as black ink composition for digital lamps.

: Dissatisfied with black ink composition for digital lighting

The ink composition test method of Table 2 is as follows.

Print Density: After printing 1000 sheets by pulp paper, measure the density of the entire printed area with a color density meter.

Back non-invasive: After printing 100 sheets by pulp paper, the density of the front part of the back side is measured by color density meter

Smearing: Observe the smearing of the letters using an optical microscope.

Friction resistance: After 100 sheets are printed with pulp paper, 10 round trips are measured with a friction tester.

Storage stability: Visually observe the emulsion collapse state of the ink composition by standing at 50 ℃ for 5 weeks.

Temperature stability: Visually observe the emulsion collapse state of the ink composition by standing at 80 ℃ for 1 week.

Drying: Visually assessing whether the ink composition on the printed page dried within 30 seconds.

Backing property: Visually assess the backing condition after printing 1000 sheets by pulp paper.

As can be seen from Table 2 above, when Example 1 is compared with Comparative Example 1, it can be seen that the stearic amine derivative improves the temperature and storage stability of the ink composition, and comparing Example 1 with Comparative Example 2 It can be seen that paraffin oil improves dryness and stability. In addition, when comparing Example 1 and Comparative Example 3 it can be seen the role of hydroxy propyl cellulose, which is a water-soluble resin, when comparing the Example 1 and Comparative Example 4 it can be seen the importance of the dark blue ultrafine raw materials, Example 1 In Comparative Example 5 and the glycerin can be seen that to improve the overall properties of the ink composition.

The black and white ink composition of the present invention has no odor because it contains no aromatic components, so it is not harmful to the human body, and the oil composition of the ink composition is low and the emulsion is not easily separated, so it is excellent in storage and stability, and ink even when printing. The separation of the paper from the drum is good, there is no clogging of the printing drum screen, there is an advantage that does not cause trouble even when left in the printing machine. In addition, by using the black and white ink composition of the present invention, it is effective to obtain a printed material having a high printing density, high bleeding property, no blurring, no staining, and clear color.

Claims (7)

Oil-in-water (W / O) type emulsified digital ink composition composed of 20 ~ 80% of oil phase and 80 ~ 20% of water phase, in which the fat-soluble resin which is long whey alkyd resin in composition ratio of oil phase component Emulsifiers containing 15%, a fat-soluble colorant consisting of carbon black, an inorganic pigment, 2-15%, and a polyoxyethylene stearic amine derivative having a HLB value of 3-10, and sorbitan monooleate at a constant ratio. Is 1 to 20%, the non-volatile solvent as a non-romatic component is 3 to 15%, the non-volatile solvent to be liquid paraffin is 5 to 20%, and the water-soluble composition to be hydroxypropyl cellulose in the composition ratio of the aqueous phase component. The resin is 1 to 10%, the water-soluble colorant which is a dark blue ultrafine raw material having a diameter of less than 1 μm is 5 to 15%, and the wetting agent which is glycerin is 3 to 10%. Digital light, characterized in that 40 to 77% added For meoksaek ink composition. delete delete delete delete delete delete