KR20140009789A - Water-based coating composition for paper and manufacturing method therof - Google Patents

Abstract

The present invention relates to a water-based coating composition for paper which protects the surface of a printed matter for a long time by increasing the abrasion resistance of the water-based coating agent for paper when paper containing a printed matter on the surface is coated with the water-based coating agent, exhibits luxurious appearance by making the surface of the printed matter glossy and improves quality of a packing box and the like manufactured by using coated paper, and a manufacturing method thereof. The manufacturing method manufactures the water-based coating agent for paper by using a stirring container in which a stirring operation is consistently performed and comprises: a step (S10) of putting styrene acryl emulsion and water into the stirring container; a step (S20) of mixing an antifoaming agent and a solvent with high boiling point and putting the ingredients into the stirring container; a step (S30) of putting wax into the stirring container; and a step (S40) of putting a surfactant into the stirring container. [Reference numerals] (S10) Put acryl emulsion and water into a stirring container; (S20) Put an antifoaming agent and a solvent with high boiling point by mixing ingredients; (S30) Put wax into the stirring container; (S40) Put a surfactant into the stirring container

Description

Water-based coating composition for paper and manufacturing method therof

The present invention relates to an aqueous coating composition for paper and a method for manufacturing the same, and in particular, to increase the wear resistance of the aqueous coating for paper so that the surface of the printed material is protected for a long time when the aqueous coating for paper is coated on a paper having a print on the surface. And an aqueous coating composition for paper and a method of manufacturing the same for improving the quality of a packaging box manufactured by using coated paper so that gloss is given to a surface of a printed matter so as to express an elegant appearance.

In the printing industry, especially in the paper packaging industry, the coating process is an essential process. That is, many coatings are made to protect the surface of the printed matter and to express a more elegant appearance.

The coating agent used for such a coating is called an over print varnish (OPV) because it is coated on the substrate. The overprint varnish is an ultraviolet curing type which is 100% of a solid content which is cured by an oil-based solvent using an organic solvent, water-based water and ultraviolet rays.

When oil-based coatings are used in packaging boxes, volatile substances that are harmful to the body are emitted, whereas water-based coatings or UV coatings are attracting attention as eco-friendly products because they do not emit harmful substances during coating and are easily recycled. In recent years, the demand for water-based coatings and ultraviolet coatings has been the majority.

However, in order to apply an ultraviolet coating, not only an expensive ultraviolet curing facility capable of implementing ultraviolet curing is required, but also an ultraviolet coating is expensive.

Aqueous coatings physically form a coating by evaporation of the solvent to exert a surface protection function. For this reason, an aqueous polymer synthetic resin becomes a main component and provides various characteristics such as wear resistance and activity by various additives. The composition and morphology of the major resins are important factors in determining the performance of the coating. Aqueous synthetic resins are acrylic resins, alkyd / polyester resins, polyurethane resins, epoxy resins, and the like. Among these, an aqueous coating agent is mainly used acrylic resin (or styrene acrylic resin).

In addition, various additives are used for the workability of the aqueous coating agent and the surface condition and surface protection function after forming the coating film. At this time, the additives include a surfactant, a solvent, a wax, an antifoaming agent, and the like.

The box containing the merchandise is loaded and shipped to the dealer or consumer. During this process, if the box itself is scratched or if the printed contents are difficult to see, it will result in a loss of value. In order to prevent such a problem from occurring, the wear resistance of the aqueous coating agent should be increased.

To improve wear resistance, the amount of wax used must be increased. However, when the amount of wax used is increased, the problem of gloss decreases. Degradation of gloss will result in poor commerciality.

Therefore, in order to manufacture a commercial packaging box, it is necessary to develop an aqueous coating composition having high abrasion resistance and high gloss effect when the aqueous coating agent is coated on the packaging box.

The present invention has been made in order to solve the above-mentioned problems, it is to increase the wear resistance of the water-based coating agent for paper, when the water-based coating agent for paper is coated on a paper having a print on the surface to protect the surface of the print for a long time and It is an object of the present invention to provide an aqueous coating composition for paper and a method of manufacturing the same for improving the quality of a packaging box manufactured using coated paper so that gloss is given to give an elegant appearance.

In order to achieve this object,

According to an aspect of the present invention,

Styrene acrylic emulsions, antifoaming agents, high boiling point solvents, waxes, surfactants and water.

The wax is characterized in that any one or two or more of polyethylene emulsion wax, paraffin wax and silicone wax are mixed.

When the total weight percentage of the styrene acrylic emulsion, antifoaming agent, high boiling point solvent, wax, surfactant, and water is 100% by weight,

The styrene acrylic emulsion is characterized in that 80 to 87% by weight.

When the total weight percentage of the styrene acrylic emulsion, antifoaming agent, high boiling point solvent, wax, surfactant, and water is 100% by weight,

The antifoaming agent is characterized in that 0.1 to 0.4% by weight.

When the total weight percentage of the styrene acrylic emulsion, antifoaming agent, high boiling point solvent, wax, surfactant, and water is 100% by weight,

The high boiling point solvent is BDG (Butyl Diglycol) is characterized in that 1 to 3% by weight.

When the total weight percentage of the styrene acrylic emulsion, antifoaming agent, high boiling point solvent, wax, surfactant, and water is 100% by weight,

The wax is characterized in that 6 to 10% by weight.

When the total weight percentage of the styrene acrylic emulsion, antifoaming agent, high boiling point solvent, wax, surfactant, and water is 100% by weight,

The surfactant is characterized in that 1 to 3% by weight.

When the total weight percentage of the styrene acrylic emulsion, antifoaming agent, high boiling point solvent, wax, surfactant, and water is 100% by weight,

The water is characterized in that 1 to 6% by weight.

According to another aspect of the present invention,

As a method of manufacturing an aqueous coating agent for paper using a stirring vessel that is continuously stirred inside,

Putting a styrene acrylic emulsion and water into the stirring vessel (S10);

Mixing the antifoaming agent and the high boiling point solvent into the stirring vessel (S20);

Putting a wax into the stirring vessel (S30); And

Putting a surfactant in the stirring vessel (S40);

And a control unit.

The wax is characterized in that any one or two or more of polyethylene emulsion wax, paraffin wax and silicone wax are mixed.

In the step (S40), the surfactant is put into the stirring vessel, characterized in that the stirring of the stirring vessel is performed for 30 minutes to 1 hour.

When the total weight percentage of the styrene acrylic emulsion, antifoaming agent, high boiling point solvent, wax, surfactant, and water is 100% by weight,

The styrene acrylic emulsion is characterized in that 80 to 87% by weight.

When the total weight percentage of the styrene acrylic emulsion, antifoaming agent, high boiling point solvent, wax, surfactant, and water is 100% by weight,

The antifoaming agent is characterized in that 0.1 to 0.4% by weight.

When the total weight percentage of the styrene acrylic emulsion, antifoaming agent, high boiling point solvent, wax, surfactant, and water is 100% by weight,

The high boiling point solvent is BDG (Butyl Diglycol) is characterized in that 1 to 3% by weight.

When the total weight percentage of the styrene acrylic emulsion, antifoaming agent, high boiling point solvent, wax, surfactant, and water is 100% by weight,

The wax is characterized in that 6 to 10% by weight.

When the total weight percentage of the styrene acrylic emulsion, antifoaming agent, high boiling point solvent, wax, surfactant, and water is 100% by weight,

The surfactant is characterized in that 1 to 3% by weight.

When the total weight percentage of the styrene acrylic emulsion, antifoaming agent, high boiling point solvent, wax, surfactant, and water is 100% by weight,

The water is characterized in that 1 to 6% by weight.

The present invention increases the abrasion resistance of the aqueous coating agent for paper so that the aqueous coating agent for paper is coated on a paper having a print on the surface, so that the surface of the print is protected for a long time and the gloss is given to the surface of the print. There is an effect that the quality of the packaging box and the like produced by using the coated paper expressed.

Figure 1 is a flow chart showing one embodiment of a process for producing an aqueous coating agent for paper according to the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Figure 1 is a flow chart showing one embodiment of a process for producing an aqueous coating agent for paper according to the present invention. At this time, each step (S10 to S40) for the aqueous coating agent for paper is carried out at room temperature.

In FIG. 1, first, water for lowering the viscosity of styrene acrylic emulsion and styrene acrylic emulsion, which are the main raw materials, is added to a stirring vessel continuously stirred inside (S10). At this time, the stirring drive in the stirring vessel is continuously performed unless the operator controls to stop the stirring drive.

The antifoaming agent and the high boiling point solvent are mixed and placed in a stirring container (S20).

Put the wax in the stirring vessel (S30). At this time, the wax is preferably any one or two or more of polyethylene emulsion wax, paraffin wax and silicone wax.

Put the surfactant in the stirring vessel (S40). At this time, the surfactant is put in a stirring vessel, the stirring of the stirring vessel is preferably performed for 30 minutes to 1 hour.

When the total weight percentage of styrene acrylic emulsion, antifoaming agent, high boiling point solvent, wax, surfactant, and water is 100% by weight, the styrene acrylic emulsion is 80 to 87% by weight, the antifoaming agent is 0.1 to 0.4% by weight, and the high boiling point is The solvent is BDG (Butyl Diglycol), 1 to 3% by weight, wax is 6 to 10% by weight, surfactant is 1 to 3% by weight and water is preferably 1 to 6% by weight.

On the other hand, after the stirring of the step (S40) is completed, a small amount of water may be added to check the viscosity to be suitable for the use viscosity.

Looking at each of the components described above in more detail as follows.

First, it is preferable that the styrene acrylic emulsion has a shell-core structure. The shell portion is an acrylic having hydrophilicity, and the core portion is an emulsion form having a composition of styrene having hydrophobicity. This is because emulsion resins generally have high solids and low viscosity resins, which can result in good gloss while slow drying and poor leveling. Means for solving these problems are as follows.

When the drying rate of the aqueous coating is slow, blocking occurs, and when the drying rate is fast, poor gloss or cracking occurs. Therefore, there is a need for a high boiling point solvent capable of maintaining an appropriate drying time.

When the content of the styrene acrylic emulsion is less than 80% by weight, the adhesion is poor, and when the content of the styrene acrylic emulsion is more than 87% by weight, the gloss decreases.

When the aqueous coating is coated on paper, it is preferable to use an antifoaming agent that can remove bubbles in the emulsion itself in order to prevent pin-hole phenomenon.

The antifoaming agent uses a silicone antifoaming agent.When the content of the antifoaming agent is used at less than 0.1% by weight, the defoaming ability decreases, the defoaming time is long, and the pinhole phenomenon occurs on the coated surface after drying, resulting in surface defects. If it is used by weight or more, there is a problem in the wettability.

High boiling point solvents may be used alone or in combination of two or more of butyl diglycol (diethylene glycol methyl ether) and dipropyl glycol methyl ether having a boiling point of 180 ° C. or higher, and when the content of the high boiling point solvent is less than 1% by weight, drying time This too fast may cause cracks on the coating surface, when used more than 3% by weight caused poor gloss or blocking.

In order to improve the wear resistance, mainly wax is used. When excessive amount of wax is used, the wear resistance is improved, but the gloss is reduced. Therefore, in order to improve the wear resistance and minimize the deterioration of gloss, it is recommended to use two or more waxes. In addition, it is preferable to select a wax of an appropriate particle because the wax determines the properties of wear resistance and gloss depending on the particle size.

That is, the wax can be used alone or two or more of polyethylene emulsion wax, paraffin wax, and silicone wax. If the wax content is less than 6% by weight, the wax is good, but the wear resistance is poor and there is a possibility of blocking. When used at 10% by weight or more, the wear resistance is excellent but the gloss is lowered.

In order to improve the adhesion between the coating agent and the paper, it is preferable to use a surfactant having wettability.

For example, if the surfactant is less than 1% by weight to use an anionic surfactant, the wettability of the coating is lowered, resulting in poor wear resistance, and when it is used more than 3% by weight, the adhesion to the ink surface is poor. It improves abrasion resistance, but the viscosity increases and the defoaming decreases.

In addition, referring to Tables 1 to 4, each Example and Comparative Example according to the present invention are as follows.

division Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Styrene acrylic emulsion 80 83 86 82 87 85 Antifoam 0.3 0.1 0.3 0.2 0.4 0.3 High boiling point solvent 3 3 One 2 One One Wax 8 7 6 10 6 8.6 Surfactants 3 2 3 One One 3 water 5.7 4.9 3.7 4.8 4.6 2.1

division Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Styrene acrylic emulsion 88 79 86 86 85 84 Antifoam 0.2 0.2 0 0.5 0.3 0.3 High boiling point solvent 2 3 One One 0 3.5 Wax 5 9.3 6 6 7 6 Surfactants 2 3 3 3 3 3 water 2.8 5.5 4 3.5 4.7 3.2 division Comparative Example 7 Comparative Example 8 Comparative Example 9 Comparative Example 10 Styrene acrylic emulsion 86 81 83 82 Antifoam 0.3 0.3 0.2 0.2 High boiling point solvent 2.5 2.5 3 3 Wax 4.6 11 8 6 Surfactants 2 2 0.5 4 water 4.5 3.8 5.3 4.8

division Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Viscosity (seconds) 27 29 26 28 28 26 Drying time (seconds) 95 90 75 90 80 75 Parcel time (second) 120 210 165 180 135 155 Polish 71 72 72 70 73 71 Leveling ability Good Good Good Good Good Good Wear Resistance (Number of Times) 1,500 1,500 1,500 1,500 1,500 1,500

division Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Viscosity (seconds) 31 25 29 29 30 29 Drying time (seconds) 120 85 80 80 50 210 Parcel time (second) 250 185 350 105 210 450 Polish 71 69 71 72 71 61 Leveling ability Bad Good Good Good Good Good Wear Resistance (Number of Times) 1,500 1,100 1,500 1,200 1,500 1,500 division Comparative Example 7 Comparative Example 8 Comparative Example 9 Comparative Example 10 Viscosity (seconds) 28 27 28 32 Drying time (seconds) 100 85 75 80 Parcel time (second) 165 180 120 380 Polish 72 64 70 71 Leveling ability Good Bad Good Good Wear Resistance (Number of Times) 1,000 1,500 1,200 1,500

Table 1 shows the compounding ratio of the aqueous coating composition for high wear-resistant paper coating in weight% and Table 2 shows the other compounding ratios in weight% for comparison with Table 1.

And Table 3 shows the test results of viscosity, drying time, defoaming time, gloss, wear resistance, etc. according to the mixing ratio of Table 1 and Table 4 shows the viscosity, drying time, defoaming time according to the mixing ratio of Table 2 to compare with Table 3 It shows test results such as gloss and wear resistance.

Viscosity is measured by using Cup No. 3, and the measuring method is to measure the time when the flow of the aqueous coating is lost while the finger is removed after the opening of the cup is closed with a finger and the aqueous coating is poured.

The drying time is measured by coating the aqueous coating on the test paper with a bar coater 3 at room temperature and then touching the drying time.

The defoaming time was measured by adding 5 g of water to 20 g of the aqueous coating and shaking it vigorously 100 times before disappearing all the bubbles.

Gloss is measured using a glossmeter.

The leveling property is to check the surface phenomenon staining when the test paper is coated with an aqueous coating agent 3 with a bar coater.

The abrasion resistance is determined by the number of times the ink comes out when the test paper is coated with an aqueous coating agent with a bar coater 3 and rubbed with a dried specimen in a Sutherland type wear resistance tester at a load of 900 g.

Comparing Examples 1 and 5 with Comparative Examples 1 and 2, it can be seen that the leveling property is poor, the drying time is delayed and the viscosity is increased according to the use of 88% by weight of the styrene acrylic emulsion. It can be seen that the result is poor wear resistance.

Comparing Examples 2 and 5 with Comparative Examples 3 and 4, when the antifoaming agent is not used, the antifoaming property is lowered, and when 0.5% by weight of the antifoaming agent is used, the wettability is lowered due to the properties of the silicone, which is the main component of the antifoaming agent, and the wear resistance is lowered. can see.

Comparing Examples 2 and 3 with Comparative Examples 5 and 6, drying time may be too fast without using a high boiling point solvent, resulting in cracking of the coated surface, and 3.5% by weight may result in gloss degradation. .

Comparing Examples 4 and 5 with Comparative Examples 7, 8, the gloss is lowered according to the use of 11% by weight of the wax, the leveling property is poor, and the wear resistance is lowered when the 4.6% by weight is used.

Comparing Examples 5 and 6 with Comparative Examples 9 and 10, the wettability is deteriorated with the use of 0.5 wt% of the surfactant, resulting in poor abrasion resistance and defoamer resistance with the use of the 4 wt%.

Based on the results of these experiments, the aqueous coating composition for high abrasion resistance paper coating is 80 to 87% by weight of styrene acrylic emulsion, 0.1 to 0.4% by weight of antifoaming agent, 1 to 3% by weight of high boiling point solvent, 6 to 10% by weight of wax, surfactant It is preferable that it consists of a composition containing 1-3 weight% and 1-6 weight% of water.

The present invention increases the abrasion resistance of the water-based coating agent for paper so that the water-based coating agent for paper is coated on paper having a print on the surface, so that the surface of the print is protected for a long time and the gloss is given to the surface of the print. There is an advantage that the quality of the packaging box and the like is produced using the paper expressed and coated.

Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. In addition, it is a matter of course that various modifications and variations are possible without departing from the scope of the technical idea of the present invention by anyone having ordinary skill in the art.

Claims (17)

An aqueous coating composition for paper, comprising styrene acrylic emulsion, antifoaming agent, high boiling point solvent, wax, surfactant, and water.
The method according to claim 1,
The wax is an aqueous coating composition for paper, characterized in that any one or two or more of polyethylene emulsion wax, paraffin wax and silicone wax are mixed.
The method according to claim 1,
When the total weight percentage of the styrene acrylic emulsion, antifoaming agent, high boiling point solvent, wax, surfactant, and water is 100% by weight,
The styrene acrylic emulsion is an aqueous coating composition for paper, characterized in that 80 to 87% by weight.
The method according to claim 1,
When the total weight percentage of the styrene acrylic emulsion, antifoaming agent, high boiling point solvent, wax, surfactant, and water is 100% by weight,
The antifoaming agent is an aqueous coating composition for paper, characterized in that 0.1 to 0.4% by weight.
The method according to claim 1,
When the total weight percentage of the styrene acrylic emulsion, antifoaming agent, high boiling point solvent, wax, surfactant, and water is 100% by weight,
The high boiling point solvent is BDG (Butyl Diglycol) and the aqueous coating composition for paper, characterized in that 1 to 3% by weight.
The method according to claim 1,
When the total weight percentage of the styrene acrylic emulsion, antifoaming agent, high boiling point solvent, wax, surfactant, and water is 100% by weight,
The wax is an aqueous coating composition for paper, characterized in that 6 to 10% by weight.
The method according to claim 1,
When the total weight percentage of the styrene acrylic emulsion, antifoaming agent, high boiling point solvent, wax, surfactant, and water is 100% by weight,
The surfactant is an aqueous coating composition for paper, characterized in that 1 to 3% by weight.
The method according to claim 1,
When the total weight percentage of the styrene acrylic emulsion, antifoaming agent, high boiling point solvent, wax, surfactant, and water is 100% by weight,
The water is an aqueous coating composition for paper, characterized in that 1 to 6% by weight.
As a method of manufacturing an aqueous coating agent for paper using a stirring vessel that is continuously stirred inside,
Putting a styrene acrylic emulsion and water into the stirring vessel (S10);
Mixing the antifoaming agent and the high boiling point solvent into the stirring vessel (S20);
Putting a wax into the stirring vessel (S30); And
Putting a surfactant in the stirring vessel (S40);
Method for producing a water-based coating for paper, comprising a.
The method of claim 9,
The wax is a method for producing an aqueous coating agent for paper, characterized in that any one or two or more of polyethylene emulsion wax, paraffin wax and silicone wax are mixed.
The method of claim 9,
Putting the surfactant in the stirring vessel in the step (S40), the stirring of the stirring vessel is a method for producing an aqueous coating for paper, characterized in that performed for 30 minutes to 1 hour.
The method of claim 9,
When the total weight percentage of the styrene acrylic emulsion, antifoaming agent, high boiling point solvent, wax, surfactant, and water is 100% by weight,
The styrene acrylic emulsion is a water-based coating method for producing a paper, characterized in that 80 to 87% by weight.
The method of claim 9,
When the total weight percentage of the styrene acrylic emulsion, antifoaming agent, high boiling point solvent, wax, surfactant, and water is 100% by weight,
The anti-foaming agent is an aqueous coating agent manufacturing method for paper, characterized in that 0.1 to 0.4% by weight.
The method of claim 9,
When the total weight percentage of the styrene acrylic emulsion, antifoaming agent, high boiling point solvent, wax, surfactant, and water is 100% by weight,
The high boiling point solvent is BDG (Butyl Diglycol) is a water-based coating method for producing a paper, characterized in that 1 to 3% by weight.
The method of claim 9,
When the total weight percentage of the styrene acrylic emulsion, antifoaming agent, high boiling point solvent, wax, surfactant, and water is 100% by weight,
The wax is a method for producing an aqueous coating agent for paper, characterized in that 6 to 10% by weight.
The method of claim 9,
When the total weight percentage of the styrene acrylic emulsion, antifoaming agent, high boiling point solvent, wax, surfactant, and water is 100% by weight,
The surfactant is a water-based coating method for producing a paper, characterized in that 1 to 3% by weight.
The method of claim 9,
When the total weight percentage of the styrene acrylic emulsion, antifoaming agent, high boiling point solvent, wax, surfactant, and water is 100% by weight,
The water is a water-based coating method for producing a paper, characterized in that 1 to 6% by weight.

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