KR20220073981A - Eco-friendly release paper coating solution using reactive emulsifier - Google Patents

Abstract

The present invention relates to an eco-friendly release paper coating solution using a reactive emulsifier, and more specifically, to an eco-friendly release paper coating solution using a reactive emulsifier that does not use polyethylene as a coating layer, so that the release paper paper can be recycled, and the heat resistance of the release paper is improved. .
The present invention provides a release paper coating solution 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; And 15 to 25 parts by weight of a reactive emulsifier; may provide an eco-friendly release paper coating solution containing.

Description

Eco-friendly release paper coating solution using reactive emulsifier

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

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

The conventional release paper uses kraft paper or release paper with a high pulp content as the lowermost surface to enhance moisture resistance, and a polyethylene (PE: Polyethylene) layer and a silicone layer are sequentially stacked on the upper surface.

However, since this conventional release paper is manufactured by laminating 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, so recycling is impossible. And it causes environmental pollution problems such as the mass production of polluting waste.

In addition, since a separate incineration facility is required to process the release paper coated with the polyethylene layer, there is a problem in that the used release paper is discarded as it is left unattended, thereby contaminating the environment.

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 cannot withstand the temperature of 160°C and shrinkage occurs. Therefore, there is a problem that the process defect rate occurs.

In order to solve this problem, Korea Patent No. 10-0315994 discloses a release paper that forms a base coating layer with a water-soluble polymer material and forms a silicone release agent layer. Although the technology for the manufacturing method of .

In addition, Korean Patent Application Laid-Open No. 10-2005-0111949 discloses a method for manufacturing a silicone release paper that can be recycled by first coating with an acrylic film, and a second coating with silicone on the upper surface of the acrylic film to prevent blocking, and a technology related to a silicone release paper However, since methanol and toluene, which are petroleum-based organic solvents, are used in the preparation of the coating solution, there is a problem that the eco-friendliness is somewhat lacking.

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

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

Objects of the present invention are not limited to the objects mentioned above, and other objects not mentioned will be clearly understood by those of ordinary skill in the art from the following description.

In order to achieve the above object, the present invention provides a release paper coating solution with 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; and 15 to 25 parts by weight of a reactive emulsifier.

According to a preferred embodiment, the silicone emulsion comprises 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 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.

According to a preferred embodiment, the reactive emulsifier is sodium para-styrene sulfonate.

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

In addition, the present invention may 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 solution according to the present invention is eco-friendly because paper can be recycled because it does not form a polyethylene coating layer. The advantage is that it can be minimized.

1 is a flowchart illustrating a method for preparing an eco-friendly release paper coating solution using a reactive emulsifier according to a preferred embodiment of the present invention.

Advantages and features of the present invention, and a method of achieving them, will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in a variety of different forms, and only these embodiments allow the disclosure of the present invention to be complete, and common knowledge in the technical field to which the present invention belongs It is provided to fully inform the possessor 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 will be described in detail for the implementation of the present invention. Irrespective of the drawings, like reference numbers refer to like elements, and "and/or" includes each and every combination of one or more of the recited items.

The terminology used herein is for the purpose of describing the embodiments, and is not intended to limit the present invention. In this specification, the singular also includes the plural unless specifically stated otherwise in the phrase. As used herein, “comprises” and/or “comprising” does not exclude the presence or addition of one or more other components in addition to the stated components.

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

The eco-friendly release paper coating solution using the reactive emulsifier according to the present invention was prepared by including a silicone emulsion, an aqueous acrylic emulsion and a reactive emulsifier, and the coating solution is not formed of polyethylene, so it is separated from the release paper after use and the paper can be reused. , it is possible to minimize process defects 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. Silicone oil is generally a colorless and transparent liquid. It has characteristics such as water repellency, antifoaming property, releasability and electrical insulation properties. In addition, silicone oil is widely used in the form of an emulsion emulsified in water, and for example, it is used in the form of a water-soluble emulsion in various mold release agents, shampoos, fiber treatment agents, and the like.

Acrylic is colorless and transparent, has good chemical resistance, has good electrical insulation and water resistance, and acrylic resin is easy to process mechanically and has excellent abrasion resistance, so it is widely used in various industries. In addition, since the conventional acrylic emulsion is produced with an organic solvent, it causes various environmental problems, and therefore, an aqueous acrylic emulsion is used throughout the industry in terms of environment-friendliness.

The eco-friendly release paper coating solution using the reactive emulsifier according to the present invention is an improvement of the intermediate coating layer coated on the paper (base paper) constituting the conventional release paper, and the release paper produced by the coating solution of the present invention is laminated on the intermediate coating layer. It is preferable to include a silicone layer that allows easy peeling from the adhesive layer.

In addition, the affinity release paper coating solution using the reactive emulsifier according to the present invention is prepared in a liquid phase, and the coating layer is not formed with polyethylene, so paper can be reused. and has excellent heat resistance.

Therefore, the release paper prepared according to the present invention is a release paper with a low pulp content, rather than a release paper with a high pulp content used for conventional release paper, as the coating solution is applied between the paper and the silicone layer. It works.

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

1 is a flowchart illustrating a method for preparing an eco-friendly release paper coating solution using a reactive emulsifier according to a preferred embodiment of the present invention.

1, the eco-friendly release paper coating solution using the reactive emulsifier according to the present invention includes the steps of preparing a silicone emulsion (S10), preparing an aqueous acrylic emulsion (S20), and adding a reactive emulsifier (S30).

According to the present invention, the eco-friendly release paper coating solution includes 20 to 30 parts by weight of a silicone emulsion, 50 to 60 parts by weight of an aqueous acrylic emulsion, and 15 to 25 parts by weight of a reactive emulsifier.

According to the present invention, the eco-friendly release paper coating solution does not use an organic solvent as it uses a silicone emulsion and an aqueous acrylic emulsion in the form of an emulsion, and the reaction of the eco-friendly release paper coating solution can be made stably by using a reactive emulsifier.

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 and 20 parts by weight of a reactive emulsifier.

When the eco-friendly release paper coating solution contains more than 25 parts by weight of the reactive emulsifier, the residual adhesion rate can be improved, but the heat resistance is lowered, and when it contains less than 15 parts by weight, the reaction does not occur well, so the coating solution is not properly formed. it may not be

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

According to a preferred embodiment, the silicone emulsion comprises 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 contains 75 parts by weight of the polydimethylsiloxane, 15 parts by weight of the nonionic surfactant, and 10 parts by weight of soft water, and after mixing the polydimethylsiloxane and the nonionic surfactant, the temperature of 40 to 45° C. It is prepared by raising the temperature and stirring with a furnace, 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, the polydimethylsiloxane is used in an amount of 75 parts by weight, and when it is included in an amount of less than 70 parts by weight, it does not exhibit sufficient heat resistance characteristic of silicone oil, and 80 parts by weight When included in excess, it may lead to an increase in the nonionic surfactant as the silicone content increases.

The nonionic surfactant is sodium lauryl sulfate (Sodium Lauryl Sulfate), stearyltrimethylammonium chloride (Stearyltrimethylammonium) and polyoxyethylene alkyl ether (polyoxyethylene alkyl ether) selected from the group consisting of one or a mixture of two or more can be used. have.

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, 20 When included in excess of parts by weight, the coatability 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, and it serves to stabilize the silicone emulsion by making the reaction of the silicone emulsion uniform, and when the soft water contains more than 10 parts by weight , the stability of the silicone emulsion may be deteriorated.

In addition, since the silicone emulsion is prepared using the soft water, the soft water can stabilize the silicone emulsion, and the coating solution can form a water-resistant and oil-resistant protective film on the paper.

The silicone emulsion according to the present invention is preferably 70 to 80 parts by weight, and when it contains less than 70 parts by weight, sufficient release force cannot be obtained. Smoothness may be reduced.

Next, in the aqueous acrylic emulsion manufacturing 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 contains 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 is mixed with 55 parts by weight of 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. is manufactured by

Here, the butyl acrylate has a low glass transition temperature, and serves to impart adhesion 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 (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 methyl methacrylate, ethyl methacrylate, and tert-butyl methacrylate.

The acrylamide (Acrylamide) serves to crosslink the aqueous acrylic emulsion.

As another example, the acrylamide (Acrylamide) can 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, etc. may be added to the silicone emulsion and aqueous acrylic emulsion compositions of the present invention as needed.

Next, in the reactive emulsifier adding step (S30), the reactive emulsifier is added while stirring the silicone emulsion and the aqueous acrylic emulsion, and the reactive emulsifier has a property of imparting excellent water resistance to the eco-friendly release paper coating solution itself.

The reactive emulsifier has a function as an emulsifier in the emulsion polymerization process, so that it is immobilized by a chemical bond to the polymer backbone by copolymerizing with a monomer. By greatly reducing the amount of the emulsifier, it is possible to react more stably.

According to a preferred embodiment, the reactive emulsifier uses sodium p-styrene sulfonate.

As another example, the reactive emulsifier may be used instead of sodium vinyl sulfonate.

According to the present invention, the reactive emulsifier has an unsaturated bond structure and is a surface active monomer soluble in water, and thus can supplement the adhesion and water resistance of the coating surface.

The eco-friendly release paper coating solution using the reactive emulsifier according to the present invention can adjust the viscosity by using a thickener to improve coatability, and additionally, a tackifier, a wetting agent, a leveling agent, a thickener, an antifoaming agent, a dispersing agent, It may further include additives such as UV stabilizers, antioxidants, anti-corruption agents and fillers.

In addition, the release paper prepared with the eco-friendly release paper coating solution using the reactive emulsifier according to the present invention is composed of paper (base paper) / eco-friendly release paper coating liquid layer / silicone layer when produced as a single-sided release paper, and in the case of double-sided release paper, single-sided on both sides of the paper It has a structure of silicone layer / eco-friendly release paper coating liquid layer / paper / eco-friendly release paper coating liquid layer / silicone layer by performing the same coating operation.

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 prepared with the eco-friendly release paper coating solution using the reactive emulsifier 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. .

In addition, when used as a moisture-proof packaging material, which is a paper product packaging paper, it can be used as a final packaging paper for printing flat paper products that are 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 reactive emulsifier according to the present invention can be coated with a smooth surface even on paper (base paper) with a low smoothness as the smoothness is improved by using the reactive emulsifier.

In addition, the release paper according to the present invention forms a coating layer by coating the paper (base paper) with an eco-friendly release paper coating solution using a reactive emulsifier, and the coated paper with the coating layer according to the present invention is primed for silicone coating and put into a coating machine. , a silicone layer is formed by applying silicone on the coated paper pretreated with a primer, and as the applied silicone layer is dried using a chamber, the release paper has release property, and the dried release paper is cooled to stabilize the quality It is preferable to manufacture by

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 thereto. Content not described here will be omitted because it can be technically inferred sufficiently by a person skilled in the art.

Example 1

After mixing 75 g of polydimethylsiloxane and 15 g of sodium lauryl sulfate as a nonionic surfactant, the temperature is raised to a temperature of 40 to 45° C. and stirred, the stirring speed is lowered, and 10 g of soft water is added and further stirred for 1 hour. Silicone emulsion was prepared.

A prepared aqueous acrylic emulsion was prepared by mixing 55 g of butyl acrylate, 30 g of styrene, and 10 g of acrylamide, dropping it into ion-exchanged water at a temperature of 80 to 85° C. for 4 hours, followed by further stirring for 2 hours.

A coating solution was prepared by mixing 20 g of sodium para styrene sulfonate as a reactive emulsifier while stirring 25 g of the silicone emulsion and 55 g of the aqueous acrylic emulsion, and the coating solution was coated on paper to form a coating layer. A sample of 50 mm x 175 mm was prepared with a release paper prepared by drying and then cooling.

Comparative Example 1

Proceeded in the same manner as in Example 1, but by mixing 30 g of a reactive emulsifier, a coating solution was prepared, and a sample was prepared in the same manner as in Example 1 with the coating solution.

Comparative Example 2

The same procedure as in Example 1, but 10 g of a reactive emulsifier was mixed to prepare a coating solution, and a sample was prepared in the same manner as in Example 1 with the coating solution.

Comparative Example 3

A sample was prepared by preparing a coating solution in the same manner as in Example 1, but without adding a reactive emulsifier.

Test Example 1

After heating the samples of Example 1 and Comparative Examples 1 to 3 of the present invention at 160 ° C. to 180 ° C. for 10 minutes at 160 ° C. to 180 ° C. in order to measure the heat resistance, according to the FINAT TEST METHOD No. 3 standard, the test speed at 180 ° angle 300 mm per minute The peel force at the time of being set to was measured, and the result is shown in Table 1.

Test Example 2

In order to measure the residual adhesion, 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 peeling adhesive force was measured when the test speed was 300 mm per minute at a 180° angle. to calculate the residual adhesive ratio (ratio (%) with respect to the reference peeling force), and the obtained value was taken as the residual adhesive ratio, and the results are shown in Table 1.

division Example 1 Comparative Example 1 Comparative Example 2 Comparative Example 3 heat resistance 160℃ 155℃ 150℃ 120℃ Residual adhesion rate 84.5% 84.9 80.2 67.5

As shown in Table 1, the residual adhesion rate means the degree of residue remaining on the attachment surface during peeling, and the higher the residual adhesion rate of the release paper, the higher the performance of the release paper. Although the performance of the release paper of No. 1 was high, Example 1 showed the best heat resistance, Comparative Example 2 containing a small amount of reactive emulsifier showed low heat resistance, and Comparative Example 3 containing no reactive emulsifier showed heat resistance and heat resistance. All of the residual adhesion rates showed low values.

Test Example 3

In order to measure water resistance and oil resistance, 5 g each of water and cooking oil was applied to the sample surfaces of Examples 1 and 3 of the present invention and left at room temperature for 24 hours, and the degree of wetness of water and cooking oil was visually observed. , 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 to 5% or less, △: wet to 10% or less As shown in Table 2, Example 1 and Comparative Example 1 were not wet at all in water and cooking oil, so excellent water resistance and It showed oil resistance, and Comparative Example 2 containing a small amount of reactive emulsifier had excellent water resistance, but oil resistance showed a wettability of 5% or less, and Comparative Example 3 without a reactive emulsifier showed a wettability of 10% or less. .

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

Although embodiments of the present invention have been described with reference to the above and the accompanying drawings, those of ordinary skill in the art to which the present invention pertains can practice the present invention in other specific forms without changing its technical spirit or essential features. You can 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: Water-based acrylic emulsion manufacturing step
S30: Reactive emulsifier addition step

Claims (6)

In the release paper coating solution with improved heat resistance,
20 to 30 parts by weight of silicone emulsion;
50 to 60 parts by weight of an aqueous acrylic emulsion; and
An eco-friendly release paper coating solution using a reactive emulsifier containing 15 to 25 parts by weight of a reactive emulsifier. The method of claim 1,
The silicone emulsion is an eco-friendly release paper coating solution using a reactive emulsifier, characterized in that 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. The method of claim 1,
The aqueous acrylic emulsion is an eco-friendly release paper coating solution using a reactive emulsifier, 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. The reactive emulsifier is an eco-friendly release paper coating solution using a reactive emulsifier, characterized in that it is sodium p-styrene sulfonate. The method of claim 1,
An eco-friendly release paper coating solution using a reactive emulsifier, characterized in that the coating layer formed of the release paper coating solution has a heat resistance temperature of 150 to 160° C. and a residual adhesion rate of 80 to 85%. A release paper prepared by the coating solution of any one of claims 1 to 5.

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