Method for manufacturing eco-friendly embossed release paper with improved embossing treatment

Abstract

The present invention relates to an eco-friendly release liner, and more specifically, to an eco-friendly embossed release liner and a method for manufacturing the same, which eliminates conventional polyethylene (PE) processing and secures water-repellent and eco-friendly properties while enhancing air-free functionality through embossing. To this end, the method for manufacturing an eco-friendly embossed release liner comprises the steps of: forming a primer layer on one side of a paper substrate layer; forming an embossed layer on the primer layer; and forming a silicone coating layer on the embossed layer.

Description

Technology Field

[0001] The present invention relates to an eco-friendly release liner, and more specifically, to a method for manufacturing an eco-friendly embossed release liner that eliminates conventional polyethylene (PE) processing and secures water dissolution and eco-friendliness, while enhancing air-free functionality through embossing. Background Technology

[0002] Release paper (also called 'release paper') serves to protect the surface of an object while maintaining the surface properties of the object by forming an adhesive layer on one or both sides of the base paper. It is attached to the surface of the object through the adhesive layer and is peeled off and separated when the object is used.

[0003] Such release liners are widely used across various industries. Examples include packaging tapes, sticker labels, synthetic leather, and various electronic components. Meanwhile, the cross-sectional structure of the release liner is generally manufactured by applying a coating layer and a release agent layer (or adhesive layer) to one or both sides of a synthetic resin film or paper substrate.

[0004] In the manufacture of conventional release paper, polyethylene (PE) resin is a representative material forming the coating layer applied to the base paper. It prevents moisture penetration into the paper substrate and fills in the rough surface of the substrate to flatten the surface, improve gloss, and provide tensile strength. Furthermore, it plays a role in preventing the adhesive layer applied thereon from penetrating into the substrate while simultaneously enabling the formation of a smooth film.

[0005] However, such conventional release papers require a separate manufacturing process involving equipment and energy to melt solid raw materials, such as PE or PP, at high temperatures in a short period of time to coat them onto a paper substrate, and this coating layer is susceptible to high temperatures when forming adhesive or bonding layers, which can cause peeling problems.

[0006] Furthermore, regarding conventional release paper, almost the entire volume is discarded and incinerated because it is practically impossible to separate the paper substrate (pulp) from the synthetic resin coating layer even when dissolved in water for regeneration or recycling. It is pointed out that this is undesirable from an environmental perspective, as the combustion of the resin contained on the surface of the release paper during incineration has a harmful effect on the atmospheric environment and is disadvantageous in terms of resource recycling. Prior art literature

[0007] Patent Document 1: Republic of Korea Registered Patent No. 10-2025343 The problem to be solved

[0008] The present invention aims to solve the above-mentioned problems by providing a method for manufacturing an eco-friendly embossed release liner that eliminates conventional polyethylene (PE) processing and uses raw materials capable of resource recycling to ensure water dissociability and eco-friendliness, while also enhancing air-free functionality through embossing.

[0009] The above and other objects and advantages of the present invention will become apparent from the following description describing preferred embodiments. means of solving the problem

[0010] The above objective can be achieved by a method for manufacturing an eco-friendly embossed release paper, comprising the steps of: forming a primer layer on one side of a paper substrate layer; forming an embossed layer on the primer layer; and forming a silicone coating layer on the embossed layer.

[0011] The paper of the above paper substrate layer has a weight of 70 to 130 g / m² 2It is characterized by having a basis weight of 100 to 150 μm and a thickness of 100 to 150 μm.

[0012] The above primer layer is characterized by being formed by a primer composition comprising PVA resin, latex, and calcium carbonate.

[0013] The above embossing layer is characterized by being formed through an embossing forming device comprising: an unwinder for unwinding a substrate wound in a roll; a rewinder for winding the unwound substrate back into a roll shape; an embossing roll for forming an embossing pattern by applying pressure to the surface of the substrate; a coating section for performing silicone coating; a chamber for performing curing; and a cooling roll for performing cooling after curing.

[0014] The step of forming the above silicone coating layer is characterized by forming an embossed layer by the embossing forming device and then transferring it to the coating section to perform the step.

[0015] The copper plate pressure of the embossing roll is characterized by being 1,145 to 1,155 kgf / cm².

[0016] The above-mentioned embossing layer is characterized in that the length of one side of the embossing (either horizontal or vertical) is 920㎛ to 980㎛, the ribs between the embossings are 300 to 320㎛, and the depth is 13 to 17㎛. Effects of the invention

[0017] According to the present invention, by excluding conventional polyethylene (PE) processing and using raw materials with excellent resource circularity and water dispersibility, it is possible to secure eco-friendliness while exhibiting stable release power, and furthermore, provide an eco-friendly embossed release paper with enhanced air-free function through embossing.

[0018] In addition, according to the present invention, in the manufacture of eco-friendly embossed release paper, through a series of continuous processes including an embossing surface treatment step and process features, it is possible to achieve the effects of process simplification, cost reduction, and shortening of processing time, and to form the specifications or shapes of the embossing pattern more precisely, thereby significantly contributing to the improvement of overall quality.

[0019] The above-mentioned eco-friendly embossed release liner can maintain high inherent physical properties of the release liner, such as release strength, along with excellent eco-friendliness.

[0020] The above-mentioned eco-friendly embossed release liner can be applied, for example, to interior sheets, double-sided tape, packaging tape, masking tape, sticker labels, medical patches, synthetic leather, various electronic components, etc., but the examples of application are not limited thereto.

[0021] However, the effects of the present invention are not limited to those mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art from the description below. Brief explanation of the drawing

[0022] Figure 1 schematically shows the structure of an eco-friendly embossed release liner according to one embodiment of the present invention. FIG. 2 is a diagram showing the manufacturing process of an eco-friendly embossed release liner according to one embodiment of the present invention in sequence. Figure 3 is a photograph showing an embossing roll used for embossing treatment during the manufacturing process of an eco-friendly embossed release paper according to one embodiment of the present invention. FIGS. 4 and FIGS. 5 are enlarged photographs showing the surface of an embossed layer formed according to one embodiment of the present invention. FIG. 6 is a photograph of an actual product of an eco-friendly embossed release liner manufactured according to one embodiment of the present invention. Specific details for implementing the invention

[0023] The present invention will be described in detail below with reference to the embodiments and drawings. These embodiments are presented merely as examples to explain the invention more specifically, and it will be obvious to those skilled in the art that the scope of the invention is not limited by these embodiments.

[0024] Furthermore, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present invention pertains, and in the event of a conflict, the description in this specification, including the definitions, shall prevail.

[0025] To clearly explain the proposed invention in the drawings, parts unrelated to the description have been omitted, and similar parts throughout the specification have been given similar reference numerals. Furthermore, when a part is described as "comprising" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components. Additionally, the term "part" as described in the specification refers to a single unit or block that performs a specific function.

[0026] In each step, identification codes (1st, 2nd, etc.) are used for convenience of explanation and do not describe the order of the steps; the steps may be performed differently from the specified order unless a specific order is clearly indicated in the context. That is, the steps may be performed in the same order as specified, substantially simultaneously, or in the reverse order.

[0028] Hereinafter, embodiments and examples of the present invention will be described in detail with reference to the attached drawings. However, the present invention may not be limited to these embodiments and examples and drawings.

[0030] Figure 1 schematically shows the structure of an eco-friendly embossed release liner according to one embodiment of the present invention.

[0031] Referring to FIG. 1, the eco-friendly embossed release liner may include: a paper substrate layer (100); a primer layer (200) formed on one side of the paper substrate layer (100); an embossed layer (300) formed on the primer layer (200); and a silicone coating layer (400) formed on the embossed layer (300).

[0032] The above-mentioned eco-friendly embossed release liner can ensure human safety, water dispersibility, resource circularity, and eco-friendliness by not using polyethylene (PE) film and organic solvents as in conventional release liner, and may have enhanced air-free functionality while exhibiting stable release power.

[0034] First, a paper substrate layer (100) may be prepared. The paper substrate layer (100) may be composed of a material commonly referred to as paper. The paper substrate layer (100) may be made of paper with excellent strength and support.

[0035] The above paper may include paper base paper made of pulp, such as, for example, all types of kraft paper including general kraft paper, extended kraft paper, and semi-extended kraft paper, white paper, white release paper, yellow release paper, single / double-sided art paper, roll paper, and food paper. In some cases, the paper base layer (100) may use primer-treated clay-coated paper. However, the types of materials constituting the paper base layer (100) are not limited thereto.

[0036] The paper of the paper substrate layer (100) has a weight of 50 to 150 g / m² 2 The basis weight, specifically, 70 to 130 g / m² 2 The weight of, for example, 130 g / m 2It is desirable to have a basis weight of .

[0037] The above paper substrate layer (100) may be formed with a thickness of 100 to 200 μm, specifically 100 to 150 μm, more specifically 130 to 140 μm, for example, 135 μm. If the thickness of the above paper substrate layer (100) deviates from the aforementioned range, it may not have sufficient support, and its durability may be reduced, such as by being damaged by folding due to low hardness, or the weight of the release liner may increase, leading to increased distribution costs and manufacturing costs.

[0039] Next, a primer layer (200) may be formed on one side of the paper substrate layer (100). The primer layer (200) may be formed by coating a primer composition on one side of the paper substrate layer (100).

[0040] The primer layer (200) may smooth the rough upper surface of the paper substrate layer (100) to increase the efficiency of the subsequent embossing process and facilitate the smooth coating of a silicone coating layer, which is a release material layer, on the embossed surface. In addition, the primer layer (200) can replace the conventionally used PE film, is environmentally friendly, and improves water dispersibility, thereby ensuring excellent recyclability and resource circularity.

[0041] The above primer composition is a water-soluble composition and may include, for example, PVA resin, latex and calcium carbonate. In this case, the latex may refer to styrene butadiene rubber (SBR).

[0042] The above primer composition forms a primer layer to perform the function of a conventional PE resin layer, while enhancing physical properties such as preventing curling and moisture penetration, and providing excellent recyclability by exhibiting water dissociation dispersibility.

[0043] The method of coating to form the primer layer (200) is not particularly limited and can be performed according to known techniques.

[0044] For example, the primer composition may be stirred using a stirrer for 1 to 2 hours, and then coated on the paper substrate layer (100) using, for example, a gravure coating method or a reverse kiss method. After coating, the primer layer (200) may be formed by drying with hot air or cold air at 100 to 120°C for 2 to 5 minutes.

[0045] The thickness of the primer layer (200) is preferably formed to be, for example, 1 to 3 μm, or, for example, 2 μm.

[0046] If the thickness of the primer layer (200) exceeds the aforementioned range, there is a concern that the subsequent embossing process will not proceed smoothly, thereby degrading the quality of the embossing layer.

[0047] In some cases, a printed layer (not shown) may be formed on one side of the paper substrate layer (100) before forming a primer layer (200) on the paper substrate layer (100). The printed layer (not shown) may be intended to indicate identification or design of the release paper product, for example, a logo, color, pattern, etc.

[0048] The above-mentioned printing layer may be formed according to known techniques commonly used in the field, provided that the physical properties of the primer layer formation are not impaired.

[0050] Next, an embossed layer (300) can be formed on the primer layer (200).

[0051] The above embossed layer (300) may refer to an embossed pattern layer having an uneven structure that can form a passage for air movement, formed by embossing the surface of the paper substrate layer (100), specifically, the primer layer (200) formed on the substrate layer (100). The shape of the embossed pattern constituting the embossed layer (300) is not particularly limited, and any shape is possible as long as a passage for air movement can be formed.

[0053] FIG. 2 is a diagram showing the manufacturing process of an eco-friendly embossed release liner according to one embodiment of the present invention in sequence.

[0054] Referring to FIG. 1 and FIG. 2 together, the paper substrate layer (100) having the primer layer (200) formed thereon can be fed into an embossing forming device and passed between two or more rotating rolls to perform an embossing surface treatment through a process of processing with heat and pressure.

[0055] The above-described embossing device may be capable of performing a continuous process in the form of a roll-to-roll, for example, and may comprise an unwinder for unwinding a substrate wound in a roll, a rewinder for winding the unwound substrate back into a roll shape, an embossing roll for forming an embossing pattern by applying pressure to the surface of the substrate; a coating section for performing silicone coating; a chamber for performing curing; and a cooling roll for performing cooling after curing.

[0056] In addition, a plurality of units are provided for each section from the unwinder to the rewinder, for example, a corona unit, an infeed unit, an embossing unit, a printing unit, a gravure 3-stage roll, a gravure 5-stage roll, chamber zones 1 to 5, a cooling roll unit, and an outfeed unit are provided and connected in sequence to the unwinder, and these can be connected and arranged up to the rewinder.

[0057] However, the configuration of the above-mentioned embossing device is not limited thereto and may further include known components commonly used in the field without limitation.

[0058] After unwinding the paper substrate layer (100) on which the primer layer (200) is formed using an unwinder, an embossing roll can be used to form an embossment.

[0060] FIG. 3 is a photograph showing an embossing roll used for embossing treatment during the manufacturing process of an eco-friendly release paper according to one embodiment of the present invention.

[0061] Referring to Fig. 3, the embossing roll can be used by attaching a copper plate with a pattern processed by CNC or laser to the roll, or by processing the pattern on the metal roll itself.

[0062] For example, the embossing roll may be in the form of an embossing pattern formed on a steel core roller. Specifically, the embossing roll has a structure in which a top roll, an embo pattern roll, and a bottom roll are stacked in sequence, and these can constitute an embossing unit.

[0063] In order to form the embossed layer (300), pressure may be applied from top to bottom using the embossing roll. At this time, the conditions for forming the embossment may be, for example, by controlling the copper plate pressure, copper plate specifications, copper plate transport speed, etc. Depending on these conditions, the size, depth, sharpness, and degree of spreading of the embossed pattern constituting the embossed layer (300) may vary.

[0064] Under the above embossing formation conditions, the copper plate pressure may be, for example, 1,145 to 1,155 kgf / cm², or, for instance, 1,150 kgf / cm². The moving speed of the copper plate may be, for example, 10 to 50 mpm. The width of the embossing roll may be formed to a size of, for example, 1,400 to 1,700 mm. For example, it is preferable that the width of each of the top roll and bottom roll be formed to 1,700 mm, and the width of the embo pattern roll be formed to 1,400 mm.

[0065] Eco-friendly embossed release paper (130g / m²) manufactured according to one embodiment of the present invention 2 The embossing of the embossing layer (300) of the standard is preferably formed in a square shape, and the length of one side of the embossing (horizontal or vertical) is formed to be 920㎛ to 980㎛, and the ribs, which represent flat or connected parts between the embossings, are 300 to 320㎛, for example, 310㎛, and the depth, which represents the depth of the embossing layer, is 13 to 17㎛, specifically 15㎛.

[0066] In addition, when forming an embossment, for example, a 30-ton load cell can be used for uniform hydraulic pressure, and a dancer can be used to provide stability during operation. Additionally, grooves can be created in the rollers to provide smoothness to the fabric.

[0067] The conditions and methods for forming the embossing described above are not limited to those previously mentioned, and may follow known techniques commonly used in the field or be applied by modifying the design of such known techniques as desired.

[0069] Next, a silicone coating layer (400) can be formed on the embossed layer (300).

[0070] The above silicone coating layer (400) may be a release agent layer formed on the embossed layer (300). It may be formed by moving to the coating portion after the embossed layer (300) is formed, applying a silicone composition to the upper surface of the embossed layer (300), and then heat-curing it.

[0071] The above coating part may provide a coating method such as, for example, roll coating, gravure coating, extrusion coating, knife coating, Miyaba coating, dip coating, etc.

[0072] In the present invention, through a continuous process in which the embossed layer (300) is immediately transferred to a coating section to form a silicone coating layer (400), the process can be simplified and the process time can be saved.

[0073] The above silicone composition may be, for example, a solvent-free coating composition comprising a silicone component, a crosslinking agent, etc.

[0074] According to one embodiment of the present invention, the component composition of the silicone composition is characterized by being a solvent-free composition that does not contain organic solvents, and by having an optimal combination that can maintain both high release strength and the physical properties characteristic of release paper with only a minimal combination of components. As a result, compared to existing release paper manufacturing technologies, it is possible to achieve the effect of simultaneously securing excellent eco-friendliness, economic efficiency, and improved physical properties.

[0075] The above silicone composition comprises, for example, polydimethylsiloxane, a crosslinking agent, and a platinum catalyst, and may further include other known components commonly used in the field.

[0076] After coating the above silicone composition, it can be moved to a chamber to perform curing and form a silicone coating layer (400).

[0077] For example, the above curing may use a thermal curing method. For example, the above thermal curing may be performed using a hot air drying type chamber at 120 to 160°C for 10 seconds to 3 minutes, but is not limited thereto.

[0078] The thickness of the above silicon coating layer (400) can be formed to, for example, 0.5 to 2.5 μm, specifically, 0.8 to 1.2 μm, or, for example, 1 μm.

[0079] If the thickness of the silicone coating layer (400) is less than 0.8㎛, there is a concern that the detachment may not be smooth, and if the thickness of the silicone coating layer (400) exceeds 2.5㎛, the problem may occur where the silicone is excessively absorbed into the paper substrate layer (100) during the curing process and leaks out to the lower surface and side of the paper substrate layer (100).

[0080] The above silicone coating layer (400) may exhibit a release force of, for example, 5 to 15 gf / 25 mm.

[0082] After curing the above silicone coating layer (400), cooling can be performed by passing it through a cooling roll. The cooling maintains a constant temperature of the formed eco-friendly embossed release liner and can provide effects such as stabilizing the overall physical properties of the release liner, preventing shrinkage, and preventing deformation of the substrate.

[0083] The above cooling roll may be set to a temperature of 20 to 40°C, but is not limited thereto.

[0084] After performing the above cooling, the eco-friendly embossed release liner can be recovered again using a rewinder. Subsequently, further subsequent processes such as lamination, coating, and slitting can be performed.

[0086] FIGS. 4 and FIGS. 5 are photographs showing an embossed surface according to one embodiment of the present invention.

[0087] Referring to FIGS. 4 and 5, it was confirmed that the embossed layer according to one embodiment of the present invention has a distinct embossed shape and all embossed patterns are uniformly formed, and the horizontal length of the embossment is 973.606 μm, the vertical length of the embossment is 927.790 μm, the ribs are 303.397 μm and 310.158 μm, and the depth is 15 μm.

[0089] Figure 6 is an actual photograph of an eco-friendly embossed release liner manufactured according to one embodiment of the present invention.

[0090] Referring to FIG. 6, it was confirmed that the eco-friendly embossed release liner according to one embodiment of the present invention can secure excellent air-free functionality while exhibiting stable release power, and by using raw materials that allow for resource recycling without using PE film, it satisfies the standards for reducing harmful substances and pollution of the living environment, and as an eco-friendly release liner capable of dispersibility in water, it is a product capable of obtaining environmental label certification.

[0092] According to one embodiment of the present invention, by excluding conventional polyethylene (PE) processing and using raw materials with excellent resource circularity and water dispersibility, it is possible to secure eco-friendliness while exhibiting stable release power, and furthermore, provide an eco-friendly embossed release paper with enhanced air-free function through embossing.

[0093] In addition, according to the present invention, in the manufacture of eco-friendly embossed release paper, through a series of continuous processes including an embossing surface treatment step and process features, it is possible to achieve the effects of process simplification, cost reduction, and shortening of processing time, and to form the specifications or shapes of the embossing pattern more precisely, thereby significantly contributing to the improvement of overall quality.

[0094] The above-mentioned eco-friendly embossed release liner can maintain high inherent physical properties of the release liner, such as release strength, along with excellent eco-friendliness.

[0095] The above-mentioned eco-friendly embossed release liner can be applied, for example, to interior sheets, double-sided tape, packaging tape, masking tape, sticker labels, medical patches, synthetic leather, various electronic components, etc., but the examples of application are not limited thereto.

[0097] Optimal embodiments have been disclosed in the drawings and specification. Specific terms have been used herein, but are used only for the purpose of describing the invention and are not intended to limit the meaning or the scope of the invention as described in the claims. Therefore, those skilled in the art will understand that various modifications and equivalent alternative embodiments are possible therefrom. Accordingly, the true technical scope of protection of the invention should be determined by the technical spirit of the appended claims. Explanation of the symbols

[0098] 100: Substrate layer 200: Primer layer 300: Embossed layer 400: Silicone coating layer

Claims

Claim 1 The method comprises the steps of: forming a primer layer on one side of a paper substrate layer; forming an embossed layer on the primer layer; and forming a silicone coating layer on the embossed layer; wherein the embossed layer comprises: an unwinder for unwinding a substrate wound in a roll; a rewinder for winding the unwound substrate back into a roll shape; an embossing roll for forming an embossed pattern by applying pressure to the surface of the substrate; a coating section for performing silicone coating; a chamber for performing curing; and a cooling roll for performing cooling after curing. A method for manufacturing an eco-friendly embossed release paper with improved embossing treatment, characterized in that the method is performed through an embossing forming device equipped with, wherein the step of forming the silicone coating layer is performed by forming the embossing layer by the embossing forming device and then transferring it to a coating section, wherein the copper plate pressure of the embossing roll is 1,145 to 1,155 kgf / cm², the length of one side of the embossing of the embossing layer (either horizontal or vertical) is 920㎛ to 980㎛, the rib between the embossings is 300 to 320㎛, and the depth is 13 to 17㎛. Claim 2 Eco-friendly embossed release paper manufactured by the method for manufacturing eco-friendly embossed release paper with improved embossing treatment of claim 1.

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