KR102481955B1 - Eco-friendly release paper coating solution using nonionic surfactant - Google Patents

Abstract

The present invention relates to an eco-friendly release paper coating liquid, and more particularly, to an eco-friendly release paper coating liquid using a non-ionic surfactant having improved heat resistance and capable of recycling paper of release paper because polyethylene is not used as a coating layer.
The present invention relates to a release paper coating liquid with improved heat resistance, comprising: 20 to 30 parts by weight of a silicone emulsion; 50 to 60 parts by weight of an aqueous acrylic emulsion; 15 to 25 parts by weight of a nonionic surfactant; And 10 to 15 parts by weight of soft water; it is possible to provide an eco-friendly release paper coating solution containing.

Description

Eco-friendly release paper coating solution using nonionic surfactant

The present invention relates to an eco-friendly release paper coating liquid, and more particularly, to an eco-friendly release paper coating liquid using a non-ionic surfactant with improved heat resistance and capable of recycling paper of release paper because polyethylene is not used as a coating layer.

Release paper is a protective paper finely coated with a silicon release agent attached to the back side to protect adhesive components such as adhesive tapes and sheets, and has a surface treatment so that it can be easily peeled off when using the adhesive surface.

Conventional release paper has kraft paper or release paper having a high pulp content as the lowermost surface to enhance moisture resistance, and a polyethylene (PE) layer and a silicone layer are sequentially laminated on the upper surface.

However, as these conventional release papers are manufactured by combining polyethylene with paper in a coating or laminating method, when discarded after use, the paper and the coated polyethylene layer cannot be separated or decomposed from each other, making recycling impossible. and causes environmental pollution problems such as the mass production of pollutant waste.

In addition, as a separate incineration facility is required to treat the release paper coated with the polyethylene layer, the used release paper is discarded in an unattended state, causing environmental pollution.

In addition, as the release paper used in the conventional double-sided tape is made of paper, polyethylene, and silicone, the polyethylene inserted in the middle does not withstand the temperature of 160 ° C and shrinks, resulting in polyethylene shrinkage (curl, curl) There is a problem that a process defect rate occurs because release is impossible when it occurs.

In order to solve this problem, Korean Patent Registration No. 10-0315994 discloses a release paper that forms a base coating layer with a water-soluble polymer material, forms a silicone release agent layer, and then puts the release paper in water to dissolve the water-soluble polymer material and separate the silicone release agent layer. However, when preparing the silicone release agent layer, as normal hexane and toluene are mixed, toluene can cause harmful effects on the nervous system, which can threaten the safety of workers. .

In addition, Korean Patent Publication No. 10-2005-0111949 discloses a method for manufacturing a silicone release paper that is first coated with an acrylic component film and a second coating with silicone on the upper surface of the acrylic film to prevent blocking and can be recycled, and a technology related to the silicone release paper However, there is a problem that the environment-friendliness is somewhat insufficient by using methanol and toluene, which are petroleum-based organic solvents.

Republic of Korea Patent Registration No. 10-0315994 (2001.11.15.) Republic of Korea Patent Publication No. 10-2005-0111949 (2005.11.29.)

The present invention has been made to solve the above problems, and an object of the present invention is to improve heat resistance so that it can withstand a high-temperature hot air drying process, to manufacture a coating layer without using polyethylene, and to recycle the used release paper into paper. An object of the present invention is to provide an environmentally friendly release paper coating solution.

The objects of the present invention are not limited to the above-mentioned objects, and other objects 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 provides a release paper coating solution having improved heat resistance according to a preferred embodiment of the present invention, comprising: 20 to 30 parts by weight of a silicone emulsion; 50 to 60 parts by weight of an aqueous acrylic emulsion; 5 to 10 parts by weight of a nonionic surfactant; and 10 to 15 parts by weight of soft water.

According to a preferred embodiment, the silicone emulsion contains 70 to 80 parts by weight of polydimethylsiloxane, 15 to 20 parts by weight of a nonionic surfactant, and 5 to 10 parts by weight of soft water.

According to a preferred embodiment, the aqueous acrylic emulsion contains 40 to 50 parts by weight of ethyl acrylate, 25 to 35 parts by weight of styrene, and 20 to 25 parts by weight of acrylamide.

According to a preferred embodiment, the coating layer formed of the release paper coating liquid has a heat resistance temperature of 150 to 160° C. and a residual adhesion rate of 80 to 85%.

In addition, the present invention can provide a release paper manufactured by the above-described manufacturing method in order to achieve the above object.

As described above, the eco-friendly release paper coating liquid according to the present invention is eco-friendly because paper can be recycled as it does not form a polyethylene coating layer, and the heat resistance of the coating liquid is improved, resulting in process defects caused by using conventional polyethylene with low heat resistance. It is an advantage to be able to minimize .

1 is a flow chart showing a method for manufacturing an eco-friendly release paper coating liquid using a nonionic surfactant according to a preferred embodiment of the present invention.

Advantages and features of the present invention, and methods of achieving them, will become clear with reference to the detailed description of the following embodiments taken in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various different forms, only these embodiments make the disclosure of the present invention complete, and common knowledge in the art to which the present invention belongs. It is provided to fully inform the holder of the scope of the invention, and the present invention is only defined by the scope of the claims.

With reference to the accompanying drawings below, specific details for the practice of the present invention will be described in detail. Like reference numbers refer to like elements, regardless of drawing, and "and/or" includes each and every combination of one or more of the recited items.

Terms used in this specification are for describing the embodiments and are not intended to limit the present invention. In this specification, singular forms also include plural forms unless specifically stated otherwise in a phrase. As used herein, "comprises" and/or "comprising" does not exclude the presence or addition of one or more other elements other than the recited elements.

Unless otherwise defined, all terms (including technical and scientific terms) used in this specification may be used in a meaning commonly understood by those of ordinary skill in the art to which the present invention belongs. In addition, terms defined in commonly used dictionaries are not interpreted ideally or excessively unless explicitly specifically defined.

An eco-friendly release paper coating solution using a nonionic surfactant according to the present invention was prepared by preparing a coating solution including a silicone emulsion, an aqueous acrylic emulsion nonionic surfactant, and soft water. The coating solution is not formed of polyethylene and is separated from the release paper after use to obtain paper can be reused, and process defects can be minimized by improving the heat resistance of the release paper.

Silicone is widely applied in various industrial fields due to its unique inorganic and organic properties, and silicone oil is generally a colorless and transparent liquid. It has characteristics such as water repellency, antifoaming, releasability and electrical insulation. In addition, silicone oil is widely used in the form of an emulsion emulsified in water, and is used in the form of a water-soluble emulsion in, for example, various release agents, shampoos, and fabric treatment agents.

Acrylic is colorless and transparent, has good chemical resistance, good electrical insulation and water resistance, and acrylic resin is easy to process mechanically and has excellent wear resistance, so it is widely used in various industries. In addition, since conventional acrylic emulsions are produced with organic solvents and cause various environmental problems, aqueous acrylic emulsions are used throughout the industry in terms of eco-friendliness.

The eco-friendly release paper coating liquid using a nonionic surfactant according to the present invention is an improvement of the intermediate coating layer coated on the top of the paper (base paper) constituting the conventional release paper, and the release paper produced by the coating liquid of the present invention is on top of the intermediate coating layer. It is preferable to include a silicon layer that is laminated and easily peeled off from the adhesive layer.

In addition, the friendly release paper coating liquid using a nonionic surfactant according to the present invention is manufactured in a liquid phase, and the paper can be reused because the coating layer is not formed of polyethylene, and it is eco-friendly because it does not use an organic solvent, and has water resistance, oil resistance and content It has good properties and has excellent heat resistance.

Therefore, the release paper prepared according to the present invention is coated with a coating liquid between the paper and the silicone layer, so that release paper can be manufactured using general white paper with a low pulp content, rather than a release paper with a high pulp content used for conventional release papers. It works.

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

1 is a flow chart showing a method for manufacturing an eco-friendly release paper coating liquid using a nonionic surfactant according to a preferred embodiment of the present invention.

As shown in FIG. 1, the eco-friendly release paper coating solution using a nonionic surfactant according to the present invention is prepared by silicone emulsion (S10), aqueous acrylic emulsion (S20), addition of nonionic surfactant (S30) and soft water (S40). ) step.

According to the present invention, the eco-friendly release paper coating solution includes 20 to 30 parts by weight of silicone emulsion, 50 to 60 parts by weight of aqueous acrylic emulsion, 15 to 25 parts by weight of nonionic surfactant, and 10 to 15 parts by weight of soft water.

According to the present invention, the eco-friendly release paper coating liquid does not use organic solvents as silicone emulsion and aqueous acrylic emulsion are used in the form of emulsions, and the reaction of the eco-friendly release paper coating liquid can be stably achieved by using nonionic surfactants.

According to a preferred embodiment, it is appropriate to prepare a coating solution by mixing 25 parts by weight of the silicone emulsion and 55 parts by weight of the aqueous acrylic emulsion while stirring, mixing 20 parts by weight of a nonionic surfactant, and adding 10 parts by weight of soft water.

When the eco-friendly release paper coating liquid contains more than 25 parts by weight of the nonionic surfactant, it does not perform the proper function of the coating liquid, and when it contains less than 15 parts by weight, the reaction is not performed well and the coating liquid is not properly formed.

In the silicone emulsion preparation step (S10), after mixing polydimethylsiloxane and a nonionic surfactant, soft water is added to prepare a silicone emulsion, and the silicone emulsion has excellent release properties and coating properties, so that the heat resistance of the eco-friendly release paper coating liquid improve

According to a preferred embodiment, the silicone emulsion includes 70 to 80 parts by weight of polydimethylsiloxane, 15 to 20 parts by weight of a nonionic surfactant, and 5 to 10 parts by weight of soft water.

Specifically, the silicone emulsion includes 75 parts by weight of the polydimethylsiloxane, 15 parts by weight of a nonionic surfactant, and 10 parts by weight of soft water, and after mixing the polydimethylsiloxane and the nonionic surfactant, a temperature of 40 to 45 ° C. It is prepared by raising the temperature and stirring, lowering the stirring speed, adding soft water and further stirring for 1 hour.

The polydimethylsiloxane is a silicone oil, and according to a preferred embodiment, 75 parts by weight of the polydimethylsiloxane is used, and when it is included in less than 70 parts by weight, it does not exhibit sufficient heat resistance, which is a characteristic of silicone oil, and 80 parts by weight If it is included in excess, it may result in an increase in the nonionic surfactant as the silicon content increases.

The nonionic surfactant may be used in combination with one or two or more selected from the group consisting of sodium lauryl sulfate, stearyltrimethylammonium, and polyoxyethylene alkyl ether. there is.

According to a preferred embodiment, it is appropriate to use 15 parts by weight of sodium lauryl sulfate as the nonionic surfactant, and when the nonionic surfactant is included in less than 15 parts by weight, the emulsification reaction may not occur properly. When included in excess of parts by weight, the coating properties of the silicone emulsion may be impaired.

According to a preferred embodiment, it is appropriate to use 10 parts by weight of the soft water, which serves to stabilize the silicone emulsion by making the reaction of the silicone emulsion even, and the soft water is contained in excess of 10 parts by weight , the stability of the silicone emulsion may deteriorate.

In addition, as the silicone emulsion is prepared using the soft water, the soft water can stabilize the silicone emulsion, and the coating liquid can form a water- and oil-resistant barrier on paper.

The silicone emulsion according to the present invention is preferably 70 to 80 parts by weight, when it is included in less than 70 parts by weight, sufficient release force cannot be obtained, and when it is included in more than 80 parts by weight, the crosslinking degree and dispersibility are lowered and the coating layer Smoothness may deteriorate.

Next, in the aqueous acrylic emulsion preparation step (S20), an aqueous acrylic emulsion is prepared by mixing butyl acrylate, styrene and acrylamide, and the aqueous acrylic emulsion has moisture resistance, solvent resistance and water resistance, and has excellent heat resistance. .

According to a preferred embodiment, the aqueous acrylic emulsion includes 50 to 60 parts by weight of butyl acrylate, 25 to 35 parts by weight of styrene, and 10 to 15 parts by weight of acrylamide.

Specifically, the aqueous acrylic emulsion was mixed with 55 parts by weight of the butyl acrylate, 30 parts by weight of styrene, and 10 parts by weight of acrylamide, and then added dropwise to ion-exchanged water at a temperature of 80 to 85 ° C. for 4 hours and further stirred for 2 hours. It is manufactured by

Here, the butyl acrylate has a low glass transition temperature and serves to impart adhesiveness to the aqueous acrylic emulsion.

As another example, the butyl acrylate may be replaced with one selected from ethyl acrylate and lauryl methacrylate.

The styrene has a high glass transition temperature and serves to impart strength to the aqueous acrylic emulsion.

As another example, the styrene may be used as one selected from methylmethacrylate, ethylmethacrylate, and t-Butylmethacrylate.

The acrylamide serves to cross-link the aqueous acrylic emulsion.

As another example, the acrylamide may be used as one selected from methacrylic acid, 2-hydroxyethyl methacrylate, and itaconic acid.

In addition, other preservatives, pH adjusting agents, viscosity adjusting agents, stabilizers and the like may be added to the silicone emulsion and aqueous acrylic emulsion compositions of the present invention, if necessary.

Next, in the step of adding the nonionic surfactant (S30), the nonionic surfactant is added while stirring the silicone emulsion and the aqueous acrylic emulsion, and the nonionic surfactant emulsifies the silicone emulsion and the aqueous acrylic emulsion. added to increase stability.

The nonionic surfactant has a low critical micelle concentration, high solubilization power, and low foaming power, thereby increasing the stability of the eco-friendly release paper coating liquid.

According to a preferred embodiment, the nonionic surfactant is polyoxyethylene alkyl ether.

According to another embodiment, the nonionic surfactant may be added in consideration of the HLB value (Hydrophile-Lipophile Balance, hydrophilic-lipophilic balance).

At this time, the nonionic surfactant may be added by mixing two different components, alkylphenol polyoxyethylene ether, polyoxyalkylene alkyl ester, sodium lauryl Two or more selected from the group consisting of Sodium Lauryl Sulfate and Stearyltrimethylammonium may be mixed and used.

The nonionic surfactant is preferably a mixture of a component with a small HLB value and a component with a large HLB value, more preferably, a small HLB value is 5 to 12, and a large HLB value is selected from 12 to 20, respectively, to obtain a final HLB value It is appropriate to adjust to 10 to 13.

In addition, when two or more of the nonionic surfactants are mixed and used, stability at room temperature and high temperature is improved.

Next, in the soft water adding step (S40), soft water is added to the coating liquid to which the non-ionic additive is added to prepare a coating liquid, and the soft water is added to increase the stability of the eco-friendly release paper coating liquid.

According to the present invention, the soft water is stirred for 30 minutes after adding a nonionic surfactant while stirring the silicone emulsion and the acrylic emulsion, and lowering the stirring speed to add 10 to 15 parts by weight of soft water and stir for 30 minutes it is desirable

Here, the soft water is preferably added after adding the nonionic surfactant, and when the soft water is added together with the nonionic surfactant, no reaction occurs due to the addition of the soft water.

According to a preferred embodiment, 10 parts by weight of the soft water is added, and when added in less than 10 parts by weight, there is no reaction that occurs according to the addition of the soft water, and when added in excess of 15 parts by weight, the stability of the environmentally friendly release paper coating liquid is increased. Rather, there is a problem of falling.

The eco-friendly release paper coating solution using a nonionic surfactant according to the present invention can adjust the viscosity using a thickener to improve coating properties, and additionally, an antistatic agent, a tackifier, a wetting agent, a leveling agent, and a thickener. , Antifoaming agents, dispersing agents, UV stabilizers, antioxidants, anti-rotting agents and additives such as fillers may be further included.

In addition, the release paper made of the eco-friendly release paper coating liquid using the nonionic surfactant according to the present invention is composed of paper (base paper) / eco-friendly release paper coating liquid layer / silicone layer in the case of single-sided release paper, and in the case of double-sided release paper, both sides of the paper By performing the same coating operation as the cross section, it has a structure of silicone layer / eco-friendly release paper coating liquid layer / paper / eco-friendly release paper coating liquid layer / silicon layer.

According to the present invention, the aqueous acrylic emulsion included in the eco-friendly release paper coating liquid layer exhibits excellent heat resistance and moisture resistance in addition to solvent resistance and water resistance.

When the release paper made of the eco-friendly release paper coating liquid using the nonionic surfactant according to the present invention is used for synthetic leather or other film casting, it can be used as a heat-resistant release paper by utilizing the heat resistance and solvent resistance properties of the aqueous acrylic emulsion. can

In addition, when used as a moisture-proof packaging material for paper products, it can be used as a final packaging material for printing flat paper products sensitive to moisture by utilizing the moisture-proof property of the aqueous acrylic emulsion.

In addition, the eco-friendly release paper coating solution using the nonionic surfactant according to the present invention can increase the emulsion stability of the coating solution by using the nonionic surfactant.

In addition, the release paper according to the present invention is coated with an eco-friendly release paper coating solution using a nonionic surfactant on paper (base paper) to form a coating layer, and the coated paper having the coating layer according to the present invention is primed for silicone coating and applied to the coater In addition, silicone is applied on the coated paper pretreated with a primer to form a silicone layer, and as the coated silicone layer is dried using a chamber, the release paper has release properties, and to stabilize the quality of the dried release paper It is preferably prepared by cooling treatment.

Hereinafter, the configuration and operation of the present invention will be described in more detail through preferred embodiments of the present invention. However, the following examples are provided to aid understanding of the present invention, and the scope of the present invention is not limited to the following examples. Contents not described herein can be technically inferred by those skilled in the art, so descriptions thereof will be omitted.

Example 1

After mixing 75 g of polydimethylsiloxane and 15 g of sodium lauryl sulfate as a nonionic surfactant, the temperature was raised and stirred at a temperature of 40 to 45 ° C., and 10 g of soft water was added while lowering the stirring speed, followed by additional stirring for 1 hour. Silicone emulsion was manufactured.

A mixture of 55 g of butyl acrylate, 30 g of styrene, and 10 g of acrylamide was added dropwise to ion-exchanged water at a temperature of 80 to 85° C. for 4 hours and further stirred for 2 hours to prepare an aqueous acrylic emulsion.

While stirring 25 g of the silicone emulsion and 55 g of the aqueous acrylic emulsion, 20 g of polyoxyethylene alkyl ether was added as a nonionic surfactant, stirred for 30 minutes, lowered the stirring speed, added with 10 g of soft water, and stirred for 30 minutes to obtain a coating solution. The coating solution was coated on paper to form a coating layer, and after primer treatment, silicon coating was performed, and a sample of 50 mm x 175 mm was prepared with a release paper prepared by drying in a chamber and cooling treatment.

Comparative Example 1

Proceed in the same manner as in Example 1, but a coating solution was prepared by mixing 30 g of a nonionic surfactant, and a sample was prepared in the same manner as in Example 1 with the coating solution.

Comparative Example 2

Proceed in the same manner as in Example 1, but a coating solution was prepared by mixing 10 g of a nonionic surfactant, and a sample was prepared in the same manner as in Example 1 with the coating solution.

Comparative Example 3

Samples were prepared by preparing a coating solution in the same manner as in Example 1, but without adding a nonionic surfactant.

Test Example 1

In order to measure heat resistance, the samples of Example 1 and Comparative Examples 1 to 3 of the present invention were heated at 160 ° C to 180 ° C for 10 minutes, and then according to FINAT TEST METHOD No. 3 standard, at a 180 ° angle, the test speed was 300 mm per minute The peel force was measured when it was set to, and the results are shown in Table 1.

Test Example 2

In order to measure the residual adhesiveness, the samples of Example 1 and Comparative Examples 1 to 3 of the present invention were tested according to the FINAT TEST METHOD No.3 standard, and the peel adhesive force was measured at a test speed of 300 mm per minute at an angle of 180 °. The residual adhesion rate (ratio (%) to the standard peel force) was calculated, and the obtained value was used as the residual adhesion rate, and the results are shown in Table 1.

division Example 1 Comparative Example 1 Comparative Example 2 Comparative Example 3 heat resistance 160℃ 153℃ 150℃ 128℃ Residual Adhesion 82.5% 83.7% 81.1% 77.5%

As shown in Table 1, the residual adhesion rate means the degree of residue remaining on the adhesive surface during peeling, and as the performance of the release paper is evaluated higher as the residual adhesion rate is higher, Example 1 and Comparative Example Although the performance of the release paper of 1 was high, Example 1 showed excellent heat resistance, and Comparative Example 2, which contained a small amount of nonionic surfactant, showed low heat resistance, and Comparative Example 3, which did not contain a nonionic surfactant showed low values for both heat resistance and residual adhesiveness.

Test Example 3

In order to measure water resistance and oil resistance, 5 g of water and cooking oil were applied to the surface of each sample of Example 1 and Comparative Examples 1 to 3 of the present invention, left at room temperature for 24 hours, and the degree of wetness of water and cooking oil was visually observed. , and the results are shown in Table 2.

division Example 1 Comparative Example 1 Comparative Example 2 Comparative Example 3 water resistance ◎ ◎ ◎ ◎ oil resistance ◎ ○ ○ △

◎: Not wet at all, ○: Wet at 5% or less, △: Wet at 10% or less As shown in Table 2 above, Example 1 showed excellent water resistance and oil resistance as it was not wet at all in water and cooking oil. , Comparative Example 1 containing a large amount of nonionic surfactant and Comparative Example 2 containing a small amount of nonionic surfactant had excellent water resistance, but showed a wettability of 5% or less in oil resistance, and a comparison that did not contain a nonionic surfactant Example 3 showed a wetness of 10% or less.

In addition, the eco-friendly release paper coating liquid according to the present invention has excellent water resistance and oil resistance, and since the coating layer is manufactured without using polyethylene, the used release paper can be recycled as paper, and has heat resistance to withstand a high-temperature hot air drying process. improved

Although the embodiments of the present invention have been described with reference to the above and accompanying drawings, those skilled in the art to which the present invention pertains can implement the present invention in other specific forms without changing the technical spirit or essential features. You will understand that there is Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive.

S10: silicone emulsion manufacturing step
S20: aqueous acrylic emulsion manufacturing step
S30: Non-ionic surfactant addition step
S40: Soft water addition step

Claims (6)

In the release paper coating liquid with improved heat resistance,
20 to 30 parts by weight of a silicone emulsion;
50 to 60 parts by weight of an aqueous acrylic emulsion;
15 to 25 parts by weight of a nonionic surfactant; and
10 to 15 parts by weight of soft water; including,
The nonionic surfactant is polyoxyethylene alkyl ether,
The silicone emulsion is prepared with 70 to 80 parts by weight of polydimethylsiloxane, 15 to 20 parts by weight of a nonionic surfactant and 5 to 10 parts by weight of soft water,
As the silicone emulsion is prepared using the soft water, the soft water can stabilize the silicone emulsion, and the coating liquid forms a water- and oil-resistant barrier film on the paper,
The coating layer formed of the release paper coating liquid has a heat resistance temperature of 150 to 160 ° C and a residual adhesive rate of 80 to 85%. delete According to claim 1,
The aqueous acrylic emulsion is an eco-friendly release paper coating liquid using a nonionic surfactant, characterized in that 50 to 60 parts by weight of butyl acrylate, 25 to 35 parts by weight of styrene, and 10 to 15 parts by weight of acrylamide. delete delete A release paper prepared by the coating liquid of any one of claims 1 and 3.

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