KR20090104305A - Nonconducting ink composition for halogen free-type and manufacturing method of ink composition - Google Patents

Abstract

PURPOSE: A halogen free-type nonconductive ink composition is provided to improve concentration and adhesive force of a ink composition while evenly dispersing carbon black particles and coating it with a non-conductive resin. CONSTITUTION: A halogen free-type nonconductive ink composition comprises: a non-conductive resin mixture 50 ~ 55 weight% mixed with cellulose acetate, urethane resin, polyester resin and polyesterpolyol; carbon black 10 ~ 15 weight%; solvent 25 ~ 30 weight% mixed with at least one selected from the group consisting of methyl ethyl ketone, toluene and ethylacetate; and at least one mixing additive 1 ~ 2 weight% selected from wax and silica.

Description

Non-conducting ink composition for halogen free-type and manufacturing method of ink composition

The present invention relates to an ink composition and a method for producing an ink composition having a minimum content of halogen and excellent in nonconductivity.

Inks are manufactured to have different characteristics according to color and use, and the type and compounding ratio of each component constituting the ink may be different in order to match the characteristics, but basically the ink uses a pigment for color expression and a resin and resin for adhesion. Dissolves the solvent in common.

Herein, the resin is coated with pigments, each of which is sufficiently dispersed in a state of dissolving in a solvent, having fluidity. Close contact.

On the other hand, ink is widely used in fields related to electronic devices such as printing used in electronic devices such as printers, copiers, and faxes that automatically output printed matter, packaging for painting the case of electronic devices, or screen protection of LCD screens. . Therefore, it is preferable that the ink has non-conductivity to prevent malfunction of the electronic device as well as to increase the induction efficiency of the droplet upon particle discharge. In addition, in the electronics industry, in order to minimize interference with electronic components, ink having a volume resistance of more than 10 ⁹ Ω is required.

Typical inks have a relatively low volume resistivity of 10 ⁷ Ω when printed on plastic films. This is because the carbon black widely used as the composition constituting the ink contains activated carbon having conductivity, and thus the conductivity of the carbon black is reflected throughout the ink. For reference, carbon black is a black powder produced when incomplete combustion of natural gas, oil, acetylene, tar, wood, etc. is mainly used as a raw material for ink, printing ink, paint, etc. And chemical composition are well known.

Conventionally, in order to improve the nonconductivity of the ink composition, an ink composition has been developed in which carbon black particles are individually coated with a resin of a nonconductive material to maximize the volume resistance. By the way, the resin of the non-conductive material used to manufacture the ink composition is a harmful component to the human body as well as a halogen component, such as polyvinyl chloride (PVC) resin, the process of incineration or processing the printed matter printed with the conventional ink composition Has released substances that could cause environmental pollution.

Accordingly, there is an urgent need for an ink composition that limits the conductivity of carbon black while retaining the properties of the ink such as printability, adhesion, gloss and concentration while including a non-halogen resin. However, it has been technically very difficult to increase the volume resistivity of inks comprising carbon black more than 100 times from the volume resistivity of common inks to meet the standards required by the electronics industry while minimizing contamination.

Accordingly, the present invention has been made to solve the above problems, while maintaining the properties of the ink as it is, the halogen component harmful to the human body and the environment is removed, non-conductive improved halogen-free to minimize the reaction with electronic devices It is a technical problem to provide a type of nonconductive ink composition and a method for producing an ink composition.

The present invention to achieve the above technical problem,

50 to 55% by weight of a non-conductive resin mixture in which cellulose acetate, urethane resin, polyester resin and polyester polyol are mixed; 10-15 weight% carbon black; 25-30% by weight of one or more solvents mixed in the group consisting of methyl ethyl ketone, toluene and ethyl acetate; Halogen free type non-conductive ink composition consisting of 1 to 2% by weight of at least one mixed additive selected from wax and silica.

The present invention to achieve the above technical problem,

27 to 33% by weight of cellulose acetate, 10 to 15% by weight of carbon black, 6 to 8% by weight of mixed solvent of methyl ethyl ketone, toluene and ethyl acetate, 1 to 2% by weight of at least one additive selected from wax or silica and polyester resin 4 to 6% by weight of the mixture of the polyester polyol and a first step of mixing for 1 to 2 hours by mixing in a mixer;

A second step of dispersing the stirred mixture in the first step for 4 to 5 hours using a disperser operating at 900 to 1000 RPM; And

A third step of further mixing and stirring the urethane resin 18 to 22% by weight, the adjuvant adjuvant 1 to 2% by weight, 20 to 24% by weight of a mixed solvent of methyl ethyl ketone, toluene, and ethyl acetate in the mixture dispersed in the second step;

It is an ink composition manufacturing method consisting of.

According to the present invention, the carbon black particles are uniformly dispersed and coated with a non-conductive resin to improve the concentration and adhesion of the ink composition, and the non-conductive resin has a minimum content of halogen, which is a kind of harmful substances, and the human body. Harmless to the environment as well as can effectively block the conductivity of the carbon black, the ink made of such a composition minimizes interference with sensitive electronic devices, thereby preventing the malfunction of the electronic devices.

As is well known, halogen is a Group 7 element of the periodic table, and among them, limited to harmful pollutants are bromine (Br) and chlorine (Cl). For reference, the allowable concentrations of bromine and chlorine are shown in [Table 1].

object Allowance Bromine (Br) 800 ppm (0.08%) Chlorine (Cl) 800 ppm (0.08%) Bromine and Chlorine Mixture 1000 ppm (0.10%)

As can be seen from the allowance of the halogen component shown in Table 1, in the synthesis of various compositions, the halogen component is limited to use only the minimum amount possible. However, since the ink composition excluding the halogen component is remarkably deteriorated in dispersibility and color development, the ink composition according to the present invention replaces polyvinyl chloride (PVC), and thus in polyurethane resin, polyester resin, polyester polyol, cellulose acetate One or more selected nonconductive resins are utilized as coatings for the carbon black particles. At this time, the illustrated non-conductive resin is mixed at 28 to 30% by weight.

The non-conductive resin thus prepared is mixed with each other for coating of black pigment carbon black particles. On the other hand, the ink composition according to the present invention further mixes the non-conductive additive in order to lower the conductivity. Wax or silica may be applied as such additives, and placed in the form of powders between the carbon black particles. As a result, the non-conductive additive increases the volume resistivity of the ink composition by forcibly spaced the gap between the carbon black particles while preventing the conduction between the carbon black particles.

Mixing of the carbon black powder, the non-conductive resin and the non-conductive additive is performed in the mixer for about 1 to 2 hours, through which the carbon black particles and the non-conductive additive are sufficiently coated with the non-conductive resin.

Subsequently, the mixture of the carbon black powder, the non-conductive resin and the non-conductive additive is added to a disperser and dispersed at 900 to 1000 RPM for 4 to 5 hours. The dispersed mixture thus forms an even distribution without agglomeration between the carbon black particles and the non-conductive additive particles, so that the color of the ink according to the present invention is expressed uniformly.

When the above-mentioned dispersion process is completed, the urethane resin is mixed so that physical properties are maintained by supplementing the loosened viscosity during the dispersion process.

The ink composition formed through this process retains the properties required as ink, while significantly reducing conductivity and minimizing halogen content.

Meanwhile, at least one selected from an aromatic hydrocarbon solvent, a ketone solvent, an acetate solvent, and a chlorine solvent may be used as the solvent of the mixture.

The aromatic hydrocarbon solvent is used at least one selected from the group consisting of toluene, benzene and xylene, the ketone solvent is used at least one selected from the group consisting of methyl ethyl ketone, isobutyl ketone and cyclohexanone, As the acetate solvent, at least one selected from the group consisting of ethyl acetate and butyl acetate is used. And as the chlorine solvent may be used at least one selected from the group consisting of methylene chloride and chloroform.

In the ink composition of the present invention, the solvent ratio is preferably 25 to 30% by weight.

Specific embodiments will be described below based on the constitution of the ink composition according to the present invention described above, but the ink composition according to the present invention is not limited to the following examples.

EXAMPLE

30 g of cellulose acetate, a kind of nonconductive resin, 13 g of carbon black, and 7 g of a mixed solvent in which methyl ethyl ketone, toluene, and ethyl acetate, which are one kinds of solvents, are mixed in a 4: 4: 2 weight ratio. Meanwhile, 1 g of a mixed additive mixed with a wax and silica, which are nonconductive additives, in a 1: 1 ratio, and 5 g of a mixed resin obtained by mixing a polyester resin and a polyester polyol in a 1: 1 ratio is added.

Here, cellulose acetate is suitable for supplementing dispersibility in place of PVC, which is a conventional coating resin of carbon black, and PVC including a halogen component is a main component to have dispersibility of particles, which is an essential condition for forming an excellent ink composition. to be.

The mixture thus prepared is stirred for 1 to 2 hours using a mixer to complete the primary mixture. Through this process, the carbon black particles are coated on the non-conductive resin, so that their conductivity is greatly reduced.

Once the primary mixture is complete, the primary mixture is placed in a disperser for dispersion and at least four times at 900 to 1000 RPM for four to five hours to complete the secondary mixture.

20 g of the urethane resin, 1 g of the adhesion enhancer, methyl ethyl ketone, toluene, and ethyl acetate were mixed together in a ratio of 4: 4: 2 by weight to the secondary mixture thus prepared, followed by stirring.

1 to 3 is an image of a component test result report of an ink composition sample according to the present invention, and the component test results of the ink composition sample prepared according to [Examples] in addition to [Tables 2 and 3] below. Explain.

element unit Detection limit (MDL) result Cadmium (Cd) mg / kg (ppm) 0.5 Not detected Pb mg / kg (ppm) 5 Not detected Mercury (Hg) mg / kg (ppm) 2 Not detected Hexavalent Chromium (CrVl) mg / kg (ppm) One Not detected

[Table 2] is a test result obtained by requesting a sample of the ink composition prepared according to the above-described [Example] by SGS Testing Korea Co, Ltd., It can be confirmed that no heavy metal is detected in this sample. . Here, the detection limit (METHOD DETECTION LIMIT; MDL) means the minimum measurable concentration which is statistically different from the error range of the background solution concentration when tested according to the designated process test method.

For reference, the detection methods for cadmium, lead, and mercury were 'US EPA 3052, US EPA 6010B, ICP' method, and the detection method for hexavalent chromium was applied to 'US EPA 3060A, US EPA 7196A, UV' method. It became.

element unit Detection limit (MDL) result Bromine (Br) mg / kg (ppm) 30 Not detected Chlorine (Cl) mg / kg (ppm) 30 339 Florin (F) mg / kg (ppm) 30 Not detected Iodine (I) mg / kg (ppm) 30 Not detected

[Table 2] is a test result obtained by requesting a sample of the ink composition prepared according to the above-described [Example] by SGS Testing Korea Co, Ltd., Bromine, Florin and iodine were not detected in this sample, 339 ppm chlorine was detected. However, since the amount of chlorine detected is less than the allowable value shown in Table 1, the halogen component included in the sample is not enough to reveal the harmfulness.

For reference, the 'EN 14582: 2007, IC' method is used for the detection method of the halogen component.

1 to 3 are images of the component test result report of the ink composition sample according to the present invention.

Claims (2)

50 to 55% by weight of a non-conductive resin mixture in which cellulose acetate, urethane resin, polyester resin and polyester polyol are mixed; 10-15 weight% carbon black; 25-30% by weight of one or more solvents mixed in the group consisting of methyl ethyl ketone, toluene and ethyl acetate; Halogen-free non-conductive ink composition, characterized in that 1 to 2% by weight of at least one mixed additive selected from wax and silica. 27 to 33% by weight of cellulose acetate, 10 to 15% by weight of carbon black, 6 to 8% by weight of one or more solvents mixed with methyl ethyl ketone, toluene and ethyl acetate, and one or more additives selected from wax or silica A first step of mixing 2 wt% and a mixture of 4 to 6 wt% of a polyester resin and a polyester polyol in a mixer and stirring for 1 to 2 hours; A second step of dispersing the stirred mixture in the first step for 4 to 5 hours using a disperser operating at 900 to 1000 RPM; And 18 to 22% by weight of the urethane resin, 1 to 2% by weight of the adhesive adjuvant, and 20 to 24% by weight of a solvent containing one or more solvents in the group consisting of methyl ethyl ketone, toluene and ethyl acetate were further mixed into the mixture dispersed in the second step. A third step of stirring; Ink composition manufacturing method characterized in that consisting of.

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