KR20210147675A - Waterproof tape having improved stepped adhesion - Google Patents

Abstract

The disclosed content relates to a waterproof tape having excellent step adhesion as well as excellent impact resistance and waterproofness by forming a foamed adhesive layer each having a plurality of pores on one surface and the other surface of a base layer. The waterproof tape excellent in step adhesion according to the embodiment is formed on a base layer and one and the other surface of the base layer, respectively, and includes first and second foamed adhesive layers formed of a foamed resin, wherein the first and second foamed adhesive layers include an acrylic resin, a foaming agent, a curing agent, a solvent, and a plasticizer, wherein the foaming agent is included in an amount of 0.01 to 5 parts by weight based on 100 parts by weight of the acrylic resin.

Description

Waterproof tape with excellent step adhesion {WATERPROOF TAPE HAVING IMPROVED STEPPED ADHESION}

The present specification relates to a waterproof tape having excellent step adhesion, and more particularly, to a waterproof tape having excellent impact resistance and step adhesion that can be used in electronic devices such as smartphones, PCs, mobile medical devices, etc. will be.

A double-sided tape is mainly used for assembling an electronic device having an image display device or an input device mounted thereon. On the other hand, this double-sided tape is used to adhere a cover panel for protecting the surface of an electronic device to a touch panel module or a display panel module, or is used to bond a touch panel module and a display panel. Adhesive performance between parts is easily lost, and there is a risk of easy damage when external pressure is applied. In addition, when a mobile device carried by a user in a humid environment or a beach is submerged in water, there is a problem in that a large amount of moisture penetrates therein and the device is damaged.

As a method for improving such a problem, Patent Document 1 discloses a base layer formed by forming an acrylic foam coating layer on the upper surface of a polyester film, an adhesive layer formed on the upper and lower surfaces of the base layer, and the other than the adhesive layer It is disclosed for a double-sided tape for a touch screen panel with excellent impact resistance consisting of a release layer formed on the surface, and in Patent Document 2, (A) an epoxy resin, (B) rubber particles, (C) polyurethane, a plate-like filler and always A curable epoxy resin-based adhesive composition comprising at least one additive selected from the group consisting of an agent (D) a latent curing agent and (E) a plasticizer is disclosed.

The above-mentioned Patent Document 1 is located between the touch screen panel module and the liquid crystal module and firmly adheres the touch screen panel module and the liquid crystal module, and suggests a structure showing excellent heat resistance and impact resistance, but it is composed of five layers including a polyester film. Because it is composed, there is a problem that the tissue is not dense and the thickness can be increased. Patent Document 2 also suggests a composition capable of exhibiting excellent impact resistance while forming strong adhesion even on oil or contaminated metal surfaces, but does not present any effect on step adhesion or waterproofness.

Republic of Korea Patent Publication No. 10-2013-0092112 (2013.08.20) Republic of Korea Patent Registration No. 10-1352811 (2014.01.13)

An object of the present disclosure is to provide a waterproof tape having excellent impact resistance and waterproof properties as well as excellent step adhesion, which exhibits excellent step adhesion.

In addition, it is not limited to the technical problems as described above, and it is obvious that another technical problem may be derived from the following description.

As one embodiment, the disclosure includes a base layer and first and second foamed adhesive layers each formed on one and the other surface of the base layer, and having a plurality of pores, the first and second foamed adhesive layers Silver includes an acrylic resin, a foaming agent, a curing agent, a solvent, and a plasticizer, wherein the foaming agent is included in an amount of 0.01 to 10 parts by weight based on 100 parts by weight of the acrylic resin.

According to an embodiment disclosed in the present specification, the waterproof tape having excellent step adhesion has excellent step adhesion by forming a foamed adhesive layer formed of a foamed resin on one side and the other surface of the base layer, respectively, and thus has excellent impact resistance and waterproof properties. there is

1 is a perspective view showing a waterproof tape according to an embodiment of the content disclosed in the present specification.
Figure 2 is a schematic diagram for explaining the experimental method of Experimental Example 1.

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 may be implemented in various 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. Like reference numerals refer to like elements throughout.

In describing the embodiments of the present invention, if it is determined that a detailed description of a well-known function or configuration may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted. In addition, the terms to be described later are terms defined in consideration of functions in an embodiment of the present invention, which may vary according to intentions or customs of users and operators. Therefore, the definition should be made based on the content throughout this specification.

1 is a perspective view showing a waterproof tape according to an embodiment of the content disclosed in the present specification.

Hereinafter, a waterproof tape according to a preferred embodiment of the disclosed subject matter will be described in detail with reference to FIG. 1 .

Referring to FIG. 1 , the waterproof tape 100 according to the disclosure is formed on a base layer 10 and one and the other surfaces of the base layer 10, respectively, and first and second foamed adhesive layers made of foamed resin. (21, 22) may be included. The thickness of the waterproof tape 100 may be 100 to 400 μm, preferably 180 to 220 μm, more preferably 190 to 210 μm, and the step adhesive strength is 3.5 to 4.5 when the step is 140 to 160 μm. kgf, and the elongation may range from 200 to 350%.

The base layer 10 is a layer serving as a base material of the waterproof tape 100, and there is no particular limitation as long as it is a durable material, but polyethylene terephthalate (PET), polybutyleneterephthalate (PBT), Polyurethane (PU), Polyethylene (PE), Polypropylene (Polypropylene, PP), Polyvinylchloride (PVC), Polystyrene (PS), Polymethylmethacrylate (PMMA), At least one selected from the group consisting of Ethylene-vinylacetatecopolymer (EVA), polycarbonate (PC), polyethylenenaphthalate (PEN), and polyimide (PI), preferably It may be at least one selected from the group consisting of polyethylene (PE) and polyurethane (Polyurethane, PU). In addition, the base layer 10 may be formed of a foamed resin material, and may be in a form in which a plurality of pores are formed in the base layer 10 by foaming of the foaming agent, in which case the plurality of pores are spaced apart at regular intervals in a regular shape. However, it may be formed irregularly or may be formed in a form extending from the inside to the outside. And, the diameter of the pores may be 0.1 ~ 50㎛, preferably 0.1 ~ 10㎛, more preferably 0.1 ~ 5㎛. As described above, since the base layer 10 has a shape in which a plurality of pores are formed, elongation and step adhesion performance may be further improved.

The thickness of the base layer 10 may be 10 ~ 300㎛, preferably 50 ~ 150㎛, more preferably 80 ~ 120㎛. If the thickness of the base layer 10 is less than 10 μm, the tape may be easily deformed or contracted by an external impact, and if it exceeds 300 μm, the overall thickness of the tape may be thickened, and foamed adhesion As the thickness of the layer is formed to be relatively thin, it is not preferable because impact resistance and adhesion performance may be deteriorated.

The foamed adhesive layer 20 includes first and second foamed adhesive layers 21 and 22 respectively formed on one surface and the other surface of the base layer 10, wherein the first and second foamed adhesive layers 21 and 22 ) each may have a thickness of 10 to 150 μm, preferably 30 to 70 μm, and more preferably 40 to 60 μm. If the thickness of the first and second foamed adhesive layers 21 and 22 is less than 10 μm, the adhesive performance and impact resistance may be reduced, and if it exceeds 150 μm, the adhesive performance may be deteriorated, or desired elongation and step adhesiveness can be difficult to implement. When the foamed adhesive layer 20 satisfies the above-mentioned range, the step adhesion of the waterproof tape is excellent, and appropriate workability and durability can be realized.

The foamed adhesive layer 20 may be formed of a foamed resin, and a plurality of pores may be formed by foaming of the foaming agent. Specifically, the foamed adhesive layer 20 may include an acrylic resin, a foaming agent, a curing agent, a solvent, and a plasticizer, preferably 90 to 110 parts by weight of an acrylic resin, 0.01 to 10 parts by weight of a foaming agent, 0.01 to 5 parts by weight of a curing agent , 90 to 110 parts by weight of a solvent and 0.01 to 3 parts by weight of a plasticizer may be included.

Acrylic resin is a material added to control the adhesiveness of the foamed adhesive layer, and is a copolymer of two or more mixed monomer components. Normal butyl acrylate, 2-ethylhexyl acrylate, methyl acrylate, cyclohexyl methacrylate , acrylic acid, and preferably the acrylic resin is 40 to 60 parts by weight of normal butyl acrylate, 30 to 90 parts by weight of 2-ethylhexyl acrylate, 1 to 10 parts by weight of methyl acrylate, 1 to cyclohexyl methacrylate 5 parts by weight and 1 to 10 parts by weight of acrylic acid may be polymerized, and in this case, the weight average molecular weight may be 500,000 to 700,000, preferably 600,000. When the acrylic resin satisfies the above-mentioned range, the viscosity of the foamed pressure-sensitive adhesive layer is appropriately adjusted, so that the adhesiveness and the adhesive force can be excellent at the same time.

A foaming agent is a substance added to reduce the weight of a product by forming a pore lattice by generating gas when producing a product through the extrusion/injection process and to provide buffering, elongation, and impact resistance. There are physical foaming agents and chemical foaming agents. As the physical foaming agent, one or more selected from the group consisting of pentane, hexane, and Freon gas may be used, and as the chemical foaming agent, a bicarbonate-based inorganic foaming agent such as sodium hydrogen carbonate or hydrazine and urea (Hydrazine) may be used. Azodicarbonamide (ADCA), p,p'-oxybisbenzenesulfonylhydrazide (p,p'-oxybis(benzenesulfonyl hydrazide), OBSH), toluenesulfide prepared by polymerization and oxidation of urea) At least one organic blowing agent selected from the group consisting of phonylhydrazide (p-Toluenesulfonylhydrazide), dinitrosopentamethylene tetramine (N,N'-Dinitroso pentamethylene tetramine, DPT), and barium azodicarboxylate (BaAC) can be used Among them, the organic foaming agent may form bubbles as it decomposes and generates nitrogen and carbon dioxide gas at a temperature of 160 to 210°C. Such a foaming agent may be included in an amount of 0.01 to 10 parts by weight, preferably 0.01 to 5 parts by weight, more preferably 0.1 to 3 parts by weight, based on 100 parts by weight of the acrylic resin. If the foaming agent is less than 0.01 parts by weight, it is difficult for the foamed adhesive layer to have high moisture permeability and proper porosity, and if it exceeds 10 parts by weight, more pores may be generated by the gas generated from the foaming agent. When the above-mentioned range is satisfied, a plurality of pores are formed with an appropriate density by the gas generated from the foaming agent, so that adhesion and impact resistance may be more excellent.

A curing agent is a material added to enable cross-linking between resins, and may be appropriately selected and mixed according to the shape of the functional group of the polymer. As the curing agent, one or more selected from the group consisting of toluene diisocyanate (TDI) and isocyanate may be used.

The solvent is a material added for adjusting the viscosity correction and workability during adhesive coating, and drying of the adhesive surface and the inside, and there is no significant limitation in its use. The solvent is at least one selected from the group consisting of toluene, methyl alcohol, ethyl acetate, and methyl ethyl ketone, preferably methyl ethyl ketone. can be used

The plasticizer is a material added to provide flexibility and elasticity to facilitate molding. In the disclosed content, it is preferable to use adipic acid.

<Example 1>

Prepare a polyethylene film to a thickness of 100 μm as a base layer, and acrylic resin (50 parts by weight of normal butyl acrylate, 40 parts by weight of 2-ethylhexyl acrylate, 5 parts by weight of methyl acrylate, 3 parts by weight of cyclohexyl methacrylate, and 2 parts by weight of acrylic acid polymerization, weight average molecular weight 600,000) 100 parts by weight, methyl ethyl ketone 100 parts by weight, SDI's MSH-320 1 part by weight, toluene diisocyanate 1 part by weight, and a A mixture of 0.5 parts by weight of dipic acid was added to a thickness of 40 μm, and then coated and foamed at 170° C. to prepare a waterproof tape (200 μm) having a foamed adhesive layer having a thickness of 50 μm.

<Example 2>

100 μm thick foamed polyurethane prepared by comma-coating a mixture of 100 parts by weight of urethane resin, 100 parts by weight of methyl ethyl ketone, 1 part by weight of SDI's MSH-320 and 1 part by weight of isocyanate, followed by drying and foaming at 170° C. A waterproof tape (200 μm) was prepared in the same manner as in Example 1, except that the film was used as the base layer.

<Example 3>

100 parts by weight of urethane resin, 100 parts by weight of methyl ethyl ketone, 1 part by weight of micro-hollow balls in which silica and calcium carbonate are mixed in a 2: 1 weight ratio, and 1 part by weight of isocyanate are comma-coated, dried and foamed at 170° C. A waterproof tape (200 μm) was prepared in the same manner as in Example 1, except that the 100 μm thick foamed polyurethane film prepared by the method was used as the base layer.

<Example 4>

100 μm thick foamed polyurethane prepared by comma-coating a mixture of 100 parts by weight of urethane resin, 100 parts by weight of methyl ethyl ketone, 1 part by weight of SDI's MFL-7 and 1 part by weight of isocyanate, followed by drying and foaming at 170° C. A waterproof tape (200 μm) was prepared in the same manner as in Example 1, except that the film was used as the base layer.

<Example 5>

A waterproof tape (200 μm) was prepared in the same manner as in Example 1, except that a polyurethane film was used as the base layer.

<Comparative Example 1>

Prepare a polyethylene terephthalate film to a thickness of 25 μm as a base layer, and acrylic resin (50 parts by weight of n-butyl acrylate, 40 parts by weight of 2-ethylhexyl acrylate, methyl acrylate on one side and the other side of the polyethylene terephthalate film, respectively) 5 parts by weight, 3 parts by weight of cyclohexyl methacrylate, and 2 parts by weight of acrylic acid polymerization, weight average molecular weight 600,000) 100 parts by weight, 100 parts by weight of methyl ethyl ketone, and 1 part by weight of isocyanate A mixture of 1 part by weight was added to a thickness of 70 μm. Then, it was coated and foamed at 170° C. to prepare a waterproof tape (200 μm) having a foamed adhesive layer having a thickness of 87.5 μm.

<Comparative Example 2>

A waterproof tape (200 μm) was prepared in the same manner as in Comparative Example 1, except that a mixture of 100 parts by weight of acrylic resin, 100 parts by weight of methyl ethyl ketone, 1 part by weight of SDI's MSH-320 and 1 part by weight of isocyanate was used. did

Experimental Example 1. Physical property evaluation

In order to evaluate the physical properties of the waterproof tapes according to Examples 1 to 5, an experiment was conducted as follows.

(1) Adhesion evaluation

After cutting the waterproof tapes prepared in Examples 1 to 5 and Comparative Examples 1 and 2 to a width of 25 mm X a length of 200 mm, the adhesive strength was evaluated according to ASTM D3330 standard, and the results are shown in Table 1 below.

(2) Step adhesion evaluation

As shown in FIG. 2, the waterproof tapes (width 25mm X length 200mm) prepared in Examples 1 to 5 and Comparative Examples 1 and 2 are attached to both sides of a T-shaped block (width 50mm X length 50mm) And to another T-shaped block, a single-sided tape (thickness of 50㎛, 100㎛, 150㎛) cut to 10mm in width X 50mm in length was attached on both sides. Then, the waterproof tapes were combined and pressed so that they were crossed, and after 30 minutes at room temperature, the time of detachment was measured using a UTM facility, and the results are shown in Table 1 below.

(3) Elongation evaluation

After cutting the waterproof tapes prepared in Examples 1 to 5 and Comparative Examples 1 and 2 to 25mm in width X 150mm in length, the distance at break was measured while pulling at a speed of 50mm/min using a UTM facility. , the results are shown in Table 1 below.

(4) Impact deformation evaluation

After cutting the waterproof tapes prepared in Examples 1 to 5 and Comparative Examples 1 and 2 to 15.5mm in width X 15.5mm in length X 0.7mm in width, 45mm in width X 45mm in length X 4mm in thickness of a magnesium plate having a center hole of 10mm attached in the middle. Then, after attaching the tempered glass to the upper surface, it was allowed to sit at 24°C for 72 hours.

After positioning two blocks of 50 mm in height X 50 mm in length at an interval of 35 mm, the examples and comparative examples prepared above were positioned so that the tempered glass plate was facing down. Then, a stainless steel rod with a diameter of 5 mm was placed in the magnesium plate hole, and a 50 g weight was dropped onto the metal rod from a height of 150 mm to apply an impact until the magnesium plate and the tempered glass plate were separated. The number of applied impacts is shown in Table 1 below.

Two blocks of 50 mm in height X 50 mm in length were placed on a jig that could be fixed, and the prepared examples and comparative examples were vertically erected, and then fixed by allowing 10 mm to intersect between the blocks. A stainless steel metal rod with a diameter of 5 mm was placed on the upper surface of the vertically positioned tempered glass plate, and a 50 g weight was dropped onto the metal bar from a height of 500 mm to apply an impact until the magnesium plate and the tempered glass plate were separated. The number of applied impacts is shown in Table 1 below.

(5) Reworkability and residue evaluation

After cutting the waterproof tapes prepared in Examples 1 to 5 and Comparative Examples 1 and 2 to 25mm in width X 150mm in length, attach to a tempered glass specimen (70mm in width X 200mm in length) at room temperature, and remove after 72 hours and the results are shown in Table 1 below.

When the waterproof tape was removed from the tempered glass, it was marked as OK and NG depending on the presence or absence of breakage, and if a part of the waterproof tape remained, it was marked as a residue.

(6) waterproof rating

The waterproof tapes prepared in Examples 1 to 5 and Comparative Examples 1 and 2 were prepared in a rectangular shape of 47.3 mm in width X 47.3 mm in length X 0.7 mm in width, and this was prepared in a rectangular shape of 60 mm in width X 60 mm in length X 6.5 mm in thickness. It was attached on a polycarbonate plate of the same size as the magnesium plate. And a glass plate (width 50mm X length 50mm X thickness 2.8mm) was attached. Then, it was allowed to stand at 24° C. for 72 hours, put in a water tank filled with water, and collected after 144 hours had elapsed to check whether it was running or not, and the results are shown in Table 1 below.

Pass and NG were marked, respectively, depending on whether there was a leak.

Table 1 is a table showing the evaluation results of Experimental Example 1.

division Example 1 Example 2 Example 3 Example 4 Example 5 Comparative Example 1 Comparative Example 2 Adhesion (gf/25mm) 2,700 2,800 2,800 2,700 2,600 2,900 2,600 step
adhesion
(kgf) 50㎛ 4.8 4.7 4.5 4.5 4.3 4.1 4.5 100㎛ 4.8 4.7 4.5 4.4 4.3 3.7 4.2 150㎛ 4.2 4.1 3.8 3.9 3.6 0.5 2.3 Elongation (%) 210 250 280 240 320 40 40 impact deformation
(number) Perpendicular 8 14 10 11 6 One 10 shear 5 10 11 13 7 One 12 residue does not exist does not exist does not exist does not exist does not exist does not exist does not exist Waterproof OK OK OK OK OK NG OK

As a result, Examples 1 to 5 and Comparative Examples 1 and 2 showed similar values in the adhesive force in steps of 50 μm and 100 μm, but the adhesive strength of Examples 1 to 5 was remarkably excellent in steps of 150 μm. level was confirmed. In addition, it was found that the elongation characteristics of the Examples were very superior to those of the Comparative Examples.

Although preferred embodiments of the present invention have been described with reference to the accompanying drawings, the embodiments described in the present specification and the configurations shown in the drawings are only the most preferred embodiments of the present invention and represent all of the technical spirit of the present invention. Therefore, it should be understood that there may be various equivalents and modifications that can be substituted for them at the time of filing the present application. Therefore, the embodiments described above are to be understood as illustrative and not restrictive in all respects, and the scope of the present invention is indicated by the following claims rather than the detailed description, and the meaning and scope of the claims and their All changes or modifications derived from the concept of equivalents should be construed as being included in the scope of the present invention.

100: waterproof tape
10: base layer
20: foamed adhesive layer
21: first foamed adhesive layer
22: second foamed adhesive layer

Claims (10)

base layer; and
First and second foamed adhesive layers formed on one surface and the other surface of the base layer, respectively, and formed of a foamed resin;
The first and second foamed adhesive layers include an acrylic resin, a foaming agent, a curing agent, a solvent, and a plasticizer, wherein the foaming agent is included in an amount of 0.01 to 10 parts by weight based on 100 parts by weight of the acrylic resin. Excellent waterproof tape.
According to claim 1,
The base layer includes polyethylene terephthalate (PET), polybutyleneterephthalate (PBT), polyurethane (Polyurethane, PU), polyethylene (PE), polypropylene (PP), polychloride Vinyl (Polyvinylchloride, PVC), polystyrene (PS), polymethylmethacrylate (PMMA), ethylene-vinylacetatecopolymer (EVA), polycarbonate (polycarbonate, PC), polyethylene naphthalate (Polyethylenenaphthalate, PEN), and polyimide (Polyimide, PI), characterized in that at least one selected from the group consisting of a waterproof tape with excellent step adhesion.
According to claim 1,
The base layer is a waterproof tape with excellent step adhesion, characterized in that it is formed of a foamed resin.
According to claim 1,
The acrylic resin is 40-60 parts by weight of n-butyl acrylate, 30-90 parts by weight of 2-ethylhexyl acrylate, 1-10 parts by weight of methyl acrylate, 1-5 parts by weight of cyclohexyl methacrylate, 1-10 parts by weight of acrylic acid A waterproof tape with excellent step adhesion, characterized in that parts by weight are polymerized.
According to claim 1,
The blowing agent is azodicarbonamide (Azodicarbonamide, ADCA), p,p'-oxybisbenzenesulfonylhydrazide (p,p'-oxybis(benzenesulfonyl hydrazide), OBSH), toluenesulfonylhydrazide (p- Toluenesulfonylhydrazide), dinitrosopentamethylene tetramine (N,N'-Dinitroso pentamethylene tetramine, DPT), and barium azodicarboxylate (Bariumazodicarboxylate, BaAC), characterized in that at least one selected from the group consisting of excellent adhesion waterproof tape.
According to claim 1,
The curing agent is a waterproof tape with excellent step adhesion, characterized in that at least one selected from the group consisting of toluene diisocyanate (TDI) and isocyanate (Isocyanate).
According to claim 1,
Wherein the solvent is at least one selected from the group consisting of toluene, methyl alcohol, ethyl acetate, and methyl ethyl ketone.
According to claim 1,
The plasticizer is a waterproof tape with excellent step adhesion, characterized in that adipic acid (Adipic acid).
According to claim 1,
The first and second foamed adhesive layers have a thickness of 10 to 150 μm, respectively.
According to claim 1,
The step adhesive strength of the waterproof tape is 3.5 to 4.5 kgf when the step is 140 to 160 μm, and the elongation is 200 to 350%.

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