KR102023160B1 - Method of preparing eco-friendly coating paper for paper cup and coating paper therefrom - Google Patents

Abstract

The present invention relates to a method for preparing eco-friendly coating paper for paper cups, comprising the steps of: preparing a substrate with pulp slurry containing poly lactic acid (PLA) and pulp; preparing a water-dispersible acrylic polyurethane resin; preparing a coating solution including a mixture of the water-dispersible acrylic polyurethane resin and clay treated with an organic agent; and applying the coating solution to the substrate and drying the same to form a coating layer.

Description

TECHNICAL OF PREPARING ECO-FRIENDLY COATING PAPER FOR PAPER CUP AND COATING PAPER THEREFROM}

The present invention relates to a method for producing an eco-friendly coated paper for paper cups and coated paper accordingly.

Generally, paper food containers include paper pots, paper cups, chicken boxes, and cup noodles containers, and most of them provide water resistance and oil resistance to the paper in order to solve the hygroscopic problem of the paper.

In particular, paper food containers such as paper cups should have water resistance because they basically serve to contain water or beverages. Currently, coated papers used in most paper cups are manufactured by coating synthetic resin such as polyethylene (PE), PET (PET), polypropylene (PP), or laminating them on paper. Among the synthetic resins coated on paper, polyethylene is generally used for the purpose of waterproofing, such as food hygiene, excellent elongation, easy processing, and low price.

However, polyethylene coated paper food containers are likely to release environmental hormones by plasticizers added to polyethylene during use and disposal.

In addition, the recycling of polyethylene coated paper food container has a lot of problems in reality. For example, in order to recycle polyethylene coated paper food containers, there is a problem that pulp fibers of the paper are damaged and hardened in the process of removing polyethylene coated on paper.

In addition, in the process of removing polyethylene, most polyethylenes are not easily dissociated in a basic solution such as sodium hydroxide, but also some of them are dissociated in a basic solution at a boiling temperature. When recycling paper that has not been dissociated with polyethylene, the paper from the paper machine sticks to the surrounding rollers as it passes through the high-temperature drying process, significantly reducing the paper quality.

As such, the demand for environmentally friendly paper coatings has increased, and many attempts have been made. In Korean Patent Laid-Open No. 10-2010-0137850, core-shell structured copolymer latex is coated through a conventional papermaking facility of paper to provide basic physical properties such as water resistance, oil resistance, heat sealing, and the like. Presented a manufacturing method having eco-friendliness. The copolymerized latex presented is expected to be easily recycled because it has alkali dissociation properties, but the blocking phenomenon that the rolled papers stick together during the manufacturing process of high temperature and high pressure due to the physical properties of the copolymer latex itself leads to mass production in the actual papermaking process. There is a difficult problem to lose.

Republic of Korea Patent Publication No. 10-2010-0137850 (published Dec. 31, 2010)

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems, and to provide a method for producing an eco-friendly coated paper for paper cups in which the biodegradable coating layer coated on the substrate is alkali dissociated and is very easy to decompose.

In addition, to provide an environmentally-friendly coating paper prepared from the manufacturing method of the eco-friendly coating paper for paper cups.

The problem to be solved by the present invention is not limited to the problem (s) mentioned above, and other object (s) not mentioned will be clearly understood by those skilled in the art from the following description.

In order to achieve the above object, the present invention comprises the steps of preparing a substrate from a pulp slurry containing pulp and poly lactic acid (PLA); Preparing a water-dispersible acrylic polyurethane resin; Preparing a coating solution including a mixture of the water-dispersible acrylic polyurethane resin and the clay treated with the organic agent; It provides an environmentally friendly coating paper manufacturing method for a paper cup comprising a; and coating the coating liquid on the substrate and drying to form a coating layer.

The preparing of the substrate may include preparing a substrate to be dried on a drying roll by pulp slurry containing 50 to 90 wt% of the pulp and 10 to 50 wt% of the PLA in a paper machine.

The preparing of the water-dispersible acrylic polyurethane resin may include preparing a first prepolymer by mixing and reacting a polyol, dimethylolpropionic acid (DMPA), and an isocyanate (first step); Preparing a second prepolymer having an acrylate group by adding and reacting an acrylic monomer to the first prepolymer of the first step (second step); Preparing an acrylic polyurethane by adding a neutralizing agent to the second prepolymer of the second step (third step); And preparing a water-dispersible acrylic polyurethane resin by mixing the acrylic polyurethane of the third step with water (fourth step).

The first step may be to prepare the first prepolymer by mixing and reacting 5 to 10 parts by weight of dimethylol propionic acid and 20 to 60 parts by weight of isocyanate based on 100 parts by weight of the polyol.

The second step may be a step of preparing the second prepolymer having an acrylate group by adding 10 to 25 parts by weight of the acrylic monomer to 100 parts by weight of the polyol to the first prepolymer of the first step.

The fourth step may be to prepare a water-dispersible acrylic polyurethane resin by mixing the acrylic polyurethane of the third step with 250 to 550 parts by weight of water based on 100 parts by weight of the polyol.

In the preparing of the coating solution, 90 to 98 wt% of the water-dispersible acrylic polyurethane resin and 2 to 10 wt% of clay treated with an organic agent are mixed to prepare a mixture, and the mixture is dispersed in water to prepare a coating solution. It may be a step.

The clay treated with the organic agent may be montmorillonite modified with a quaternary ammonium salt.

The forming of the coating layer may be a step of forming a coating layer by applying the coating solution 4 to 5 g / m ² on at least one surface of the substrate.

In addition, the present invention is a substrate formed of a pulp slurry comprising pulp and PLA; And a coating layer formed of a coating liquid containing a mixture containing a water-dispersible acrylic polyurethane resin and clay treated with an organic agent.

According to the present invention, the coating layer formed on the substrate replaces the polyethylene coated paper cup which is difficult to recycle, and is easily dissociated by alkali dissolution. Thus, an eco-friendly coating paper for paper cups capable of recycling the paper pulp serving as the substrate may be manufactured.

In addition, the environmentally-friendly coating paper for paper cups prepared according to the present invention using a substrate containing pulp and biodegradable polymer, it is possible to improve the rate of spontaneous decomposition than the substrate containing only pulp when the paper cup is buried in the soil when discarded.

In addition, the eco-friendly coated paper for paper cups prepared according to the present invention can be heat-bonded using ultrasonic as well as heat-compression can greatly increase the manufacturing efficiency of the paper cups.

The effects of the present invention are not limited to the above-described effects, but should be understood to include all the effects deduced from the configuration of the invention described in the detailed description or claims of the present invention.

1 is a process flow chart illustrating a manufacturing process of an environmentally friendly coated paper manufacturing method for a paper cup according to an embodiment of the present invention.

Before describing the present invention in detail, the terms or words used herein are not to be construed as being limited to ordinary or dictionary meanings, but in order for the inventor of the present invention to explain his invention in the best way. Concepts of various terms may be properly defined and used, and furthermore, it is to be understood that these terms or words should be interpreted as meanings and concepts corresponding to the technical spirit of the present invention.

In other words, the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting the teachings of the invention. It should be understood that the term is defined in consideration.

In addition, in the present specification, the singular expressions may include the plural expressions unless the context clearly indicates otherwise, and similarly, the plural expressions may include the singular meanings. do.

Throughout this specification, when a component is described as "comprising" another component, the component may further include any other component rather than excluding any other component unless otherwise stated. It can mean that you can.

In addition, in the following, in the following description of the present invention, detailed descriptions of configurations known to unnecessarily obscure the subject matter of the present invention, for example, known technology including the related art, may be omitted.

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

1 is a process flow chart illustrating a manufacturing process of an environmentally friendly coated paper manufacturing method for a paper cup according to an embodiment of the present invention.

Referring to Figure 1, the manufacturing method of eco-friendly coated paper for paper cups according to an embodiment of the present invention comprises the steps of preparing a substrate with a pulp slurry containing pulp and PLA (Poly lactic acid); Preparing a water-dispersible acrylic polyurethane resin; Preparing a coating solution including a mixture of the water-dispersible acrylic polyurethane resin and the clay treated with the organic agent; And applying the coating solution to the substrate and drying to form a coating layer.

First, a substrate is prepared from a pulp slurry containing pulp and PLA (Poly lactic acid) (S100).

Specifically, the pulp slurry is prepared by mixing 50 to 90% by weight of the pulp and 10 to 50% by weight of the PLA, the pulp slurry is paper-making in a paper machine, and the paper substrate (for example, paper pulp) is dried on a drying roll Prepare the substrate.

PLA is a biodegradable polymer, and is generally known to be hydrolyzed by water, low molecular weight, and then degraded by microorganisms.

Therefore, in the present invention of manufacturing a substrate from a pulp slurry containing wood pulp, which is a raw material of paper, and biodegradable polymer PLA, when it is buried in the soil after using the substrate, the rate of natural decomposition can be improved, thereby reducing environmental pollution. You can.

Next, to prepare a water-dispersible acrylic polyurethane resin (S200).

This step (S200) comprises the steps of mixing and reacting a polyol, dimethylolpropionic acid (DMPA) and isocyanate to prepare a first prepolymer (first step); Preparing a second prepolymer having an acrylate group by adding and reacting an acrylic monomer to the first prepolymer of the first step (second step); Preparing an acrylic polyurethane by adding a neutralizing agent to the second prepolymer of the second step (third step); And preparing a water-dispersible acrylic polyurethane resin by mixing the acrylic polyurethane of the third step with water (fourth step).

In addition, the step (S200) may further include a step (Fifth step) by adding a chain extender to the water dispersion acrylic polyurethane resin of the fourth step.

This step (S200) will be described in detail as follows.

The first step is to prepare a first prepolymer by mixing and reacting a polyol, dimethylolpropionic acid (DMPA) and isocyanate.

Specifically, the first prepolymer may be prepared by mixing and reacting 5 to 10 parts by weight of dimethylol propionic acid and 20 to 60 parts by weight of isocyanate based on 100 parts by weight of a polyol having a number average molecular weight of 500 to 2000.

When the number average molecular weight of the polyol is less than 500, the dispersion stability is lowered, and when the coating layer is formed with a coating liquid prepared therefrom, the processability is not easy, and when the number average molecular weight is more than 2000, the coating liquid prepared therewith When the coating layer is formed, the flexibility of the coating layer may be increased so that overall physical properties may decrease.

The polyol is polytetramethylene glycol (PTMG), polycaprolactone (polycaprolactone (PCL), polypropylene glycol (PPG), polyethylene glycol (polyethylene glycol, PEG), polycarbonatediol (PCDL) It may be one or more selected from the group consisting of. Specifically, the polyol may be polytetramethylene glycol (PTMG).

The dimethylol propionic acid is used for the introduction of a hydrophilic group, with respect to 100 parts by weight of the polyol, may be used in 5 to 10 parts by weight, when less than 5 parts by weight of water dispersion stability may be lowered, 10 parts by weight When exceeded, hydrolysis resistance may fall.

The dimethylol propionic acid can be added in a dissolved state in a solvent, for example, can be added by dissolving in a solvent such as N-methyl-2-pyrrolidone, methanol or ethanol. Specifically, the solvent may be N-methyl-2-pyrrolidone.

The solvent may be added to 120 to 200 parts by weight based on 100 parts by weight of dimethylol propionic acid.

The isocyanate is aliphatic diisocyanate, 4,4-dicyclohexylmethane diisocyanate (H ₁₂ MDI), isophorone diisocyanate (IPDI), 1,4-cyclohexanedi Isocyanate (1,4-cyclohexylmethane diisocyanate, CHDI), or aromatic diisocyanate, 4,4'-diphenylmethane diisocyanate (MDI), 2,4- or 2,6-toluene It may be at least one selected from the group consisting of diisocyanate (2,4- or 2,6-toluene diisocyanate, TDI). Specifically, the isocyanate may be isophorone diisocyanate (IPDI).

The isocyanate may be used in an amount of 20 to 60 parts by weight based on 100 parts by weight of the polyol, and when less than 20 parts by weight, the polyurethane may not be sufficiently synthesized, and when it is more than 60 parts by weight, the dispersion stability may be lowered. .

In this case, the first step may be carried out for 3 hours or more in a state in which the temperature of the reactor is raised to 70 to 90 ℃.

The second step is to prepare a second prepolymer having an acrylate group by adding and reacting an acrylic monomer to the first prepolymer of the first step.

Specifically, the second prepolymer having the acrylate group may be prepared by adding 10 to 25 parts by weight of the acrylic monomer to the first prepolymer of the first step and reacting the same.

The acrylic monomer is one selected from the group consisting of methyl methacrylate, methacrylate, acrylonitrile, ethyl acrylate, ethyl methacrylate, butyl methacrylate, cyclohexyl methacrylate, methacrylonitrile and vinyl acetate It may be abnormal. Specifically, the acrylic monomer may be methyl methacrylate.

The acrylic monomer may be used in an amount of 10 to 25 parts by weight based on 100 parts by weight of the polyol used in the first step. When the acrylic monomer is less than 10 parts by weight, the effect of improving water resistance may be insignificant. The storage stability of the prepared coating liquid may be lowered.

In this case, in the second step, the prepolymer having an acrylate group may be prepared by reacting the reactor at a temperature of 70 to 90 ° C. for 3 to 8 hours.

The third step is to prepare an acrylic polyurethane by adding a neutralizing agent to the second prepolymer of the second step.

Specifically, an acrylic polyurethane may be prepared by adding a neutralizing agent until the second prepolymer of the second step becomes pH 7 to 10.

The neutralizing agent may be ammonia, ethylamine, butylamine, dimethylamine, diethylamine diisopropylamine, dimethylethylamine, benzylamine, ethanolamine, diethanolamine, triethanolamine, triethylamine, tributylamine, methyldiethanol It may be at least one selected from the group consisting of amine, diethylethanolamine, dimethylethanolamine, normal methylmorpholine, diisopropanolamine. Specifically, the neutralizing agent may be triethylamine.

The addition of the neutralizing agent is preferably carried out in a state in which the temperature of the reactor after the second step is lowered to 50 ° C or less.

The fourth step is to prepare a water-dispersible acrylic polyurethane resin by mixing the acrylic polyurethane of the third step with water.

Specifically, the water-dispersible acrylic polyurethane resin may be prepared by mixing 250 to 550 parts by weight of water in the acrylic polyurethane of the third step.

In the fourth step, two methods may be considered to prepare the water-dispersible acrylic polyurethane resin. That is, water is gradually added to the acrylic polyurethane of the third stage, followed by stirring to prepare a water-dispersible acrylic polyurethane resin, or water acrylic acrylic polyurethane resin is gradually added to the water, followed by stirring. Can be prepared.

On the other hand, in the fourth step, some alcohol solvents may be used for the purpose of improving workability as necessary, for example, methanol, ethanol, isopropanol, butanol, methylcellulose, ethyl solso as alcohol solvents. One or more selected from the group consisting of bro can be used.

The water may be used in an amount of 250 to 550 parts by weight based on 100 parts by weight of the polyol used in the first step, and when less than 250 parts by weight, coating property may be reduced when the coating liquid prepared therein is coated on a substrate. In the case of more than 550 parts by weight, it may be difficult to form a coating layer having a desired thickness when coating the substrate with a coating liquid prepared therein.

The fifth step may be optionally added, the reaction by adding a chain extender to the water-dispersible acrylic polyurethane resin of the fourth step.

Specifically, the fifth step may be to add and react 1 to 5 parts by weight of a chain extender to the water-dispersible acrylic polyurethane resin of the fourth step.

The chain extender may use diamines and diol compounds, specifically, a compound containing two primary or secondary amino groups and two hydroxyl groups, ethylenediamine, propylenediamine, butylenediamine, pentylenediamine, hexamethylenediamine , Ethylenediol, propylenediol, butylenediol, pentylenediol, hexamethylenediol may be one or more selected from the group consisting of.

The chain extender may be used in an amount of 1 to 5 parts by weight based on 100 parts by weight of the polyol used in the first step, and when it is less than 1 part by weight, the chain extension effect may be insignificant, and when it is greater than 5 parts by weight, the storage may be performed. Stability may be degraded.

On the other hand, the chain extender is preferably added after dilution in water.

Next, to prepare a coating solution including a mixture of the prepared water-dispersible acrylic polyurethane resin and clay treated with an organic agent (S300).

In this step (S300), to prepare a mixture by mixing 90 to 98% by weight of the water-dispersible acrylic polyurethane resin and 2 to 10% by weight of clay treated with an organic agent, the mixture is dispersed in water to prepare a coating solution. Step.

The clay treated with the organic agent is montmorillonite modified with a quaternary ammonium salt, and the quaternary ammonium salt is dimethylbenzyl hydrogenated tallow quaternary ammonium, and dimethyl dehydrogenated tallow quaternary. ammonium), methyl tallow bis-2-hydroxyethyl quaternary ammonium, dimethyl hydrogenated tallow 2-ethylhexyl quaternary ammonium It may be one or more selected from the group consisting of, specifically, may be dimethyl hydrogenated tallow 2-ethylhexyl quaternaryammonium.

In the present invention, montmorillonite modified with quaternary ammonium, which can be used as clay treated with an organic agent, is known as nanoclay. Such nanoclays are known as inorganic additives that can give various advantages such as excellent heat resistance, low gas permeability, and flame retardancy. However, since these nanoclays exhibit strong hydrophilicity, in the present invention, the surface of the clay is added after being modified with an organic agent in order to easily mix with the water-dispersible acrylic polyurethane.

Finally, the coating solution is applied to the substrate and dried to form a coating layer (S400).

In this step (S400), the coating solution is applied to at least one surface of the substrate 4 to 5 g / m ² and dried to form a coating layer.

The coating layer may be dried by an ultraviolet drying device consisting of an ultraviolet lamp, a hot air device, a cooling device.

Specifically, the hot air is sprayed for 1 to 5 minutes at a temperature of 50 to 200 ℃ in the hot air device, while the cooling wind is injected in the cooling device can rapidly cool the coating layer at a temperature of -10 to 10 ℃ for 1 to 3 minutes. have.

If the hot air temperature and time of the hot air device is less than 50 ℃ and 1 minute may not be able to dry to the inside of the coating layer, when 200 ℃ and more than 5 minutes may be a stain on a portion of the coated paper on which the coating layer is formed on the substrate.

In addition, when rapidly cooling the coating layer at a temperature of −10 to 10 ° C. for 1 to 3 minutes while cooling wind is injected from the cooling apparatus, curling of the coated paper may be prevented. If the cooling temperature and time is less than -10 ° C and 1 minute, a problem may occur that the coated paper sticks to the roller provided in the ultraviolet drying device. Can be generated.

UV drying device is a device applied sterilization and sterilization treatment, constant temperature, humidity control method, irradiates ultraviolet rays to the coated paper and internal curing action by the ultraviolet rays, thereby completely drying the coating layer. In addition, by changing the physical properties of the coating layer by the internal curing action to improve the hardness of the coating layer.

The coating solution may be coated on the substrate by selecting any one of a knife coating coating, a reverse roll coating, an air knife coating, and a wire rod coating method.

In this step, the coating liquid is applied to one surface of the substrate to 4 to 5 g / m ² to form a coating layer, which is coated to a small amount to ensure the production rate, the substrate (for example when applying the coating liquid in this range) It is possible to prevent curling of the paper pulp from occurring.

On the other hand, the coating layer may be made of 1 to 3 degrees, preferably to form 3 degrees, to enhance the physical properties of the eco-friendly coated paper for paper cups. For example, when coating the coating solution 12 to 15 g / m ² at a time, the water, oil, barrier properties, heat sealing properties required after coating may be lower than when continuous 3 degree coating.

By the (S100) to (S400) of the present invention can be produced an eco-friendly coating paper for paper cups.

The eco-friendly coating paper for paper cups may include a substrate containing pulp and PLA, and a coating layer containing clay treated with a water-dispersible acrylic polyurethane resin and an organic agent.

 Hereinafter, the present invention will be described in more detail with reference to Examples and Experimental Examples. However, these examples are only for the understanding of the present invention, and the scope of the present invention in any sense is not limited to these examples.

Example

Example 1

Substrate manufacturing

A pulp slurry was prepared by mixing 60 wt% of wood pulp with PLA and 40 wt% of PLA, followed by papermaking using the pulp slurry to prepare a substrate through a drying roll at 80 ° C.

Manufacture of Water Dispersible Acrylic Polyurethane Resin

30 g of polytetramethylene glycol with a number average molecular weight of 1000 and 13 g of isophorone diisocyanate were added to a 500 mL four-necked reactor connected with a thermometer, a cooler, a thermostat and a stirrer, and then 6 g of dimethylolpropionic acid was added thereto. It was dissolved in n-methyl-2-pyrrolidone and added, followed by stirring at 75 ° C. for 3 hours to obtain a first prepolymer.

4.5 g of methyl methacrylate was added to the first prepolymer and reacted for 4 hours to prepare a second prepolymer. After the preparation of the second prepolymer, the reaction temperature was lowered to 50 ° C. and triethylamine (TEA) was added slowly to adjust the pH to pH 7-10. Thereafter, 120 g of distilled water was slowly added to the reactor, followed by stirring at 1000 rpm. Then, 2 g of ethylenediamine (EDA) was added to 8 g of distilled water, and a diluted solution was added thereto, followed by stirring for 1 hour. Prepared.

Coating solution manufacturing

A mixture of 98 wt% of the water-dispersed acrylic polyurethane resin prepared above and 2 wt% of montmorillonite (Cloisite 25A) whose surface was modified with an organic agent was prepared. 40 wt% of the mixture and 60 wt% of water were stirred at room temperature to prepare a coating solution.

Eco-friendly coated paper manufacture for paper cups

The prepared substrate was put into a dry laminating coater, the coating solution was coated on the substrate with a coating amount of 4 g / m 2 to form a first coating layer, and then 4 g of the coating solution on the upper surface of the first coating layer. After coating with a coating amount of / m 2 to form a second coating layer, and again coated with a coating amount of 4 g / m 2 coating on the upper surface of the second coating layer to form a third coating layer. Then, the substrate having the first coating layer, the second coating layer, and the third coating layer formed on the ultraviolet drying device is dried, and the hot air is blown and dried for 3 minutes at 100 ° C. in the hot air device while irradiating ultraviolet rays, and then in the cooling device. Dried by rapid cooling at 5 ° C. and 3 minutes.

Example 2

In Example 1, instead of forming the first coating layer, the second coating layer, and the third coating layer on the upper surface of the substrate when manufacturing the eco-friendly coating paper for paper cups, except that only the first coating layer is formed on the upper surface of the substrate, Coated paper was prepared in the same manner.

Comparative example

Comparative Example 1

In Example 1, the coated paper was prepared in the same manner as in Example 1, except that the pulp slurry was prepared from 100% by weight of wood pulp instead of mixing PLA by 40% by weight of wood pulp when preparing the substrate. Prepared.

Experimental Example

Experimental Example 1

Biodegradability of the substrates prepared in Example 1 and Comparative Example 1 was measured, and the results are shown in Table 1 below.

Biodegradation test method: Weight loss method using cellulose and polymerase (Unit:%)

division Substrate composition Biodegradability (%) Example 1 Wood pulp 60 wt% 70.5 PLA 40 wt% Comparative Example 1 Wood pulp 100 wt% 15.2

Referring to Table 1, it can be seen that the biodegradability of Example 1 including the wood pulp and biodegradable polymer PLA is superior to the biodegradability of Comparative Example 2 containing only wood pulp without including the biodegradable polymer PLA.

Experimental Example 2

The coated papers prepared in Example 1 and Example 2 were tested for physical properties under the same conditions, and the results are shown in Table 2 below.

Properties Example 1 Example 2 Alkali dissociation and dispersibility has exist has exist Surface roughness, smoothness ◎ △ Oil resistance ◎ ○ Water supply ◎ ○ Speculation ◎ △ Breathable ◎ △ ◎ very good, ○ excellent, △ normal, × lack
Air permeability: ◎ <5cc / m ² , ○ 5 ~ 30cc / m ² , △ 30 ~ 60cc / m ² , ×> 60cc / m ²
Moisture permeability: ◎ <30 mg / m ² , ○ 30-50 mg / m ² , △ 50-200 mg / m ² , ×> 200 mg / m ²

<Test method>

Surface Roughness (Smoothness): KSM ISO 5627: 2011

Induction degree: KS M 7124: 2008

Water resistance: KS M 7025: 2012: 12

Speculation: KS M 7020: 2006: 11

Water vapor permeability (weight method): KS M ISO 2528

The surface roughness of the coated paper produced by the present invention is tested by the method of KSM ISO 5627: 2011, oil resistance is tested by the method of KS M 7124: 2008, water resistance is tested by the method of KS M 7025: 2012: 12, The breathability was tested by the method of KS M 7020: 2006: 11, and the breathability was tested by the method of KS M ISO 2528.

Table 2 showing the test results showed that the physical properties of the coated paper according to Example 1 were superior to those of the coated paper according to Example 2.

In addition, the eco-friendliness of the coated paper produced by the present invention was certified that no impurities were included in the alkali dissociation and dispersibility test of the environmental labeling target product and certification criteria (EL 103: 2007) of the Ministry of Environment, Korea, and showed no adhesiveness Did. Thus, a level of reusability has been achieved.

The above description has been made using the embodiments of the technical idea of the present invention, and those skilled in the art to which the present invention pertains various modifications and variations without departing from the essential characteristics of the present invention.

Therefore, the embodiments described in the present invention are not intended to limit the technical spirit of the present invention but to explain, and the scope of the technical spirit of the present invention is not limited by these embodiments.

The protection scope of the present invention should be interpreted by the claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

Claims (10)

Preparing a substrate with a pulp slurry comprising pulp and poly lactic acid (PLA);
Preparing a water-dispersible acrylic polyurethane resin;
Preparing a coating solution including a mixture of the water-dispersible acrylic polyurethane resin and the clay treated with the organic agent; And
Forming a coating layer by applying the coating solution to the substrate and dried; Eco-friendly coated paper manufacturing method for a paper cup comprising a.
The method of claim 1,
Preparing the substrate,
The pulp slurry comprising the pulp 50 to 90% by weight and the PLA 10 to 50% by weight in a paper machine, and the step of preparing a substrate to be dried on a drying roll to produce an eco-friendly coated paper for paper cups.
The method of claim 1,
The step of preparing the water dispersion acrylic polyurethane resin,
Preparing a first prepolymer by mixing and reacting a polyol, dimethylolpropionic acid (DMPA) and an isocyanate (first step);
Preparing a second prepolymer having an acrylate group by adding and reacting an acrylic monomer to the first prepolymer of the first step (second step);
Preparing an acrylic polyurethane by adding a neutralizing agent to the second prepolymer of the second step (third step); And
The third step of mixing the acrylic polyurethane in water to produce a water-dispersible acrylic polyurethane resin (fourth step); Eco-friendly coated paper manufacturing method for a paper cup comprising a.
The method of claim 3,
The first step,
The manufacturing method of the eco-friendly coated paper for paper cups is a step of preparing the first prepolymer by mixing and reacting 5 to 10 parts by weight of dimethylol propionic acid and 20 to 60 parts by weight of isocyanate based on 100 parts by weight of the polyol.
The method of claim 3,
The second step,
10 to 25 parts by weight of the acrylic monomer with respect to 100 parts by weight of the polyol to the first prepolymer of the first step to produce the second prepolymer having an acrylate group to produce an eco-friendly coated paper for paper cups.
The method of claim 3,
The fourth step,
The method of manufacturing an eco-friendly coated paper for a paper cup is to prepare a water-dispersible acrylic polyurethane resin by mixing the acrylic polyurethane of the third step with 250 to 550 parts by weight of water with respect to 100 parts by weight of polyol.
The method of claim 1,
Preparing the coating solution,
90 to 98% by weight of the water-dispersible acrylic polyurethane resin and 2 to 10% by weight of clay treated with an organic agent are mixed to prepare a mixture,
Dispersing the mixture in water to prepare a coating solution for paper cup manufacturing method for eco-friendly paper.
The method of claim 1,
The clay treated with the organic agent is montmorillonite modified with a quaternary ammonium salt manufacturing method for paper cups.
The method of claim 1,
Forming the coating layer,
Method of producing an environmentally-friendly coating paper for paper cups is a step of forming a coating layer by applying the coating solution 4 to 5 g / m ² on at least one side of the substrate.
A substrate formed of a pulp slurry comprising pulp and PLA; And
Eco-friendly coating paper for paper cups comprising a; coating layer formed of a coating liquid containing a mixture containing a water-dispersible acrylic polyurethane resin and clay treated with an organic agent.

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