KR20050030350A - Double-sided pressure sensitive tape - Google Patents

Abstract

Provided is a double-sided adhesive tape which is excellent in noise and vibration screening effect, has a low surface resistance, remarkably removes static elasticity and is excellent in adhesive strength and solvent resistance. The double-sided adhesive tape comprises a urethane composite resin(11) whose both sides are coated with an adhesive(10a, 10b); and a releasing paper or a releasing film is adhered to the back surface of the urethane composite resin. Preferably the urethane composite resin is obtained by adding a curing agent to a dispersion of 5-30 wt% of gamma -Fe2O3 and Ba-ferrite and 1-20 wt% of carbon black and talc dispersed in polyol, and the double-sided adhesive tape is obtained by coating the obtained one on a releasing paper or a releasing film. Preferably the urethane composite resin layer has a thickness of 5-100 micrometers and the each adhesive layer has a thickness of 0.01-2 mm.

Description

Double-sided Pressure Sensitive Tape

The present invention relates to a double-sided adhesive tape. More specifically, the present invention relates to a double-sided adhesive tape, characterized in that the adhesive is coated on both sides of the urethane composite resin and the release paper or release film is attached to the back side.

In general, materials having hardness, such as metal, glass, and acrylic, are known to have low vibration damping and sound insulation effects, and are used as casings (eg, hard disk cases) for products that generate noise and vibration using these materials. In order to do this, separate vibration damping and sound insulation means should be provided. Conventionally, double-sided tapes in which acrylic and / or rubber-based adhesives are applied to polymer base materials such as polyester or polyurethane are used as such vibration damping and sound insulation means. However, these conventional double sided tapes have some problems. For example, when a double-sided tape of a polyester or polyurethane base layer is adhered between two plates (for example, stainless steel) and then the plate is forcibly molded by pressing or punching, a double-sided tape of polyester or polyurethane base layer Due to this restoring force, the stress relief of the amorphous adhesive proceeds as time passes, and as a result, the adhesive force of the double-sided tape drops at the cut or banded portion of the plate, resulting in a fine gap between the plate and the double-sided tape. ) Occurs. In another example, when the plate is washed with a solvent such as trichloro ethane, a portion of the adhesive may be eluted or leached at the edge of the plate.

Problems inherent in conventional double-sided tapes, including these problems, could be significantly resolved by the applicant of the present application by replacing the conventional polyester or polyurethane base layer with an aluminum base layer as the base layer of the double-sided tape. The double-coated tape (aluminum double-sided adhesive tape) coated with a pressure-sensitive adhesive on both sides of the aluminum base layer is disclosed in Korean Utility Model Registration No. 20-0322853 of the applicant. Aluminum double sided adhesive tapes may also be disadvantageous in several respects as the electronics and computers in which they are used become more advanced. For example, the thickness of the aluminum sheet used as the base layer of the double-sided tape increases in proportion to reducing the noise generated when the head reads and writes the hard disk from 30 dB to 20 dB or less. Since the flexibility is reduced in proportion to the manufacturing process, that is, the coating and winding process is difficult. In another example, the electromagnetic shielding ability of the aluminum double-sided adhesive tape is not satisfactory, and may also be uncompetitive in weight or price.

Accordingly, an object of the present invention is to solve the above problems of double-sided adhesive tapes based on polyester, polyurethane, and aluminum, and to realize excellent physical properties in sound insulation, vibration damping, electric wave breaking, electrostatic removal, adhesion, holding force, solvent resistance, and the like. A new press double sided adhesive tape is provided.

The inventors of the present invention achieved the above object by using a urethane composite resin prepared by dispersing an inorganic and metal powder in a conventional polyol, adding a curing agent, and drying and curing the base layer of a double-sided adhesive tape.

The present invention provides a double-sided adhesive tape characterized in that the adhesive is coated on both sides of the urethane composite resin and a release paper or a release film is attached to the back side thereof.

One aspect of the present invention includes a double-sided adhesive tape for press composed of a three-layer sandwich of the adhesive layer + urethane composite resin layer + adhesive layer. It is manufactured by coating the adhesive on both sides to improve chemical interaction / bonding force between different materials between layers and to strengthen the flexibility and plastic deformation of the urethane composite resin sheet. It is used to prevent adhesion deterioration and crevice caused by residual stress after being pressed and punched, and shows strong resistance not to be damaged even at high temperature washing of trichloroethane. In addition, the urethane composite resin layer exhibits an effective sound insulation / dust damping function and blocks harmful electromagnetic waves.

Another aspect of the present invention includes a double-sided adhesive tape for pressing composed of a five-layer sandwich of an adhesive layer + a urethane composite resin layer + an adhesive layer + a urethane composite resin layer + an adhesive layer. Since the five-layer sandwich can further reduce noise / vibration and block harmful electromagnetic waves, the liquid phase flow is reduced by relatively reducing the thickness of the adhesive layer.

In the present invention, the urethane composite resin is prepared by mixing or dispersing an inorganic and metal powder in a conventional polyol and adding a curing agent, followed by drying (about 120 ° C.) and curing in a conventional manner. The thickness of the urethane composite resin is 5 to 100 µm. Inorganic and metal powders effectively exhibit sound insulation / dust damping effects. Metallic powders can effectively achieve harmful electromagnetic shielding and can also use electromagnetic sensors, which provides the advantage of achieving process automation. In addition, product quality control functions are added in the automated manufacturing line by using magnetic field signals caused by magnetic metal powder or sandwich panel structure dependent resonance frequencies.

Inorganic powders used in the urethane composite resin of the present invention include, but are not limited to, silicate minerals (eg, antigorite, serpentine, chrysotile, talc, ampiboles), metal oxides (eg, aluminum oxide, titanium oxide). , Iron oxides), metal salts (eg, chalk, barite, inorganic pigments), pearlite, mica, carbon black. Preferred are pearlite, talc and carbon black. These components may be used alone or in combination of two or more, with an amount of 1 to 20% based on the total weight of the urethane composite resin.

Metal powder introduced into the urethane composite resin of the present invention is not limited to these, but Supermalloy (80% Ni / Fe / Mo), SuperPerm 80 (80% Ni / Fe / Mo), SuperPerm 49 (50% Ni / Fe), Square 80 (80% Ni / Fe / Mo), Square 50 (50% Ni / Fe), Microsil (3% Si / Fe), Supermendur (49% Co / 49% Fe / V), Alloy 48 (Ni / Fe ), Round Permalloy (Ni / Fe), Square Orthonol ^?? (Ni / Fe), Mumetal (77% Ni / 5% Cu / 1.5% Cr / Fe), Ni99.6 (Ni> 99.6%), Duranik.301 (96.5% Ni / 4.4% Al / 0.3% Fe / 0.5 % Si / 0.6% Ti), NiCu30Fe (66.5% Ni / 2.5% Fe / Cu), Nicu30Al (66.5% Ni / 29.5% Cu / 2.7% Al / 1.0% Fe / 0.6% Ti), Invar Nilo 36 (36% Ni / Fe), Ni-span C-902 (42% Ni / 5.2% Cr / 2.5% Ti / 0.5% Al / Fe), 50/50 NiFe (50% Ni / 50% Fe), NiCr80 20 (80% Ni / 20% Cr), NiCr20TiAl (76% Ni / 19.5% Cr / 2.4% Ti / 1.4% Al), NiCr20Co18Ti (59% Ni / 19.5% Cr / 16.5% Co / 2.45% Ti / 1.45% Al) and NiMo30 (28% Mo / 5% Fe / 2.5% Co / 1% Cr / 0.3% V / Ni). Still other metal powders include magnetic materials (ferromagnetic, paramagnetic and diamagnetic). The most representative magnetic materials are gamma ferric oxide (γ-Fe ₂ O ₃ ), synthetic margemite (Fe ₂ O ₃ ), and Ba-ferrite. These components may be used alone or in combination of two or more, and an amount of 5% to 30% is used based on the total weight of the urethane composite resin.

Curing agent isocyanate-based (e.g. TDI (toluene diisocyanate) or Trimer, HDI (hexamethylene diisocyanate), IPDI (isophorone diisocyanate)), phosphate-based (tribasic sodium phosphate) or epoxy-based (polyamine, poly Amides, polysulfides) can be used. Its use amount is 1% to 10% based on the total weight of the urethane composite resin.

The pressure-sensitive adhesive used in the present invention includes acrylic, rubber, urethane, silicone, and the like, and typically has a low Tg (transition temperature) in order to exert strong adhesive force, and introduces a polar group that exhibits a secondary bonding force with a urethane composite resin. Energy storage for deformation is largely designed. Preferred pressure-sensitive adhesives of the present invention include acrylic pressure-sensitive adhesives. An acrylic adhesive consists of an acrylic resin, a hardening | curing agent, and the organic solvent. Acrylic resins are the main monomers, namely BA (butyl acrylate), 2-HEA (ethyl hexyl acrylate), VA (vinyl acrylate), MA (methyl acrylate), EA (ethyl acetate), MMA ( 20-50 parts by weight of methyl methacrylate) and 1-10 parts by weight of a functional monomer, ie AA (acrylic acid), HEMA (hydroxyl ethyl methacrylate), HEA, MAA (methacrylic acid) It is a mixture using vice. It provides a site of reaction with the curing agent to partially cure to inhibit residue and migration, and also to control the degree of networking (the amount of stored energy needed) by the amount of curing agent. The curing agent may use 0.5-5 parts by weight of isocyanate based (TDI (toluene diisocyanate) or Trimer, HDI (hexamethylene diisocyanate), IPDI (isophorone diisocyanate)) or glycidyl zylene diamine. The solvent is used for coating workability, in particular for viscosity and wetting with the base film, and a cosolvent system is used to optimize in consideration of the solubility of the resin and the drying process. That is, 50-70 parts by weight of ethylene acetate, toluene and hexane are mixed. The resulting functional monomer copolymer has an OH / COOH reaction site, thus forming partial networking after the curing agent reaction to control cohesion and adhesion of the pressure sensitive adhesive.

Hereinafter, the configuration of the present invention will be described in detail with reference to FIGS. 1 and 2.

The first aspect of the present invention shown in FIG. 1 is a urethane double-sided adhesive tape having a three-layer structure. After coating a urethane composite resin solution containing a curing agent to a release paper or a release film and drying (about 120 ° C.) and curing, a urethane composite resin film 11 having a thickness of 15 μm was prepared, and a polymer adhesive 10a was formed on both sides of the urethane film. , 10b) transfer coating, and using a double-sided release paper or a release film to produce a double-sided adhesive tape in a roll (roll), one surface (iron plate, glass plate, acrylic plate, etc.) (12a) of one side of the double-sided adhesive tape It adheres to the adhesive 10a coated on it, and attaches one side of the other plate 12b to the adhesive 10b of the other side of the double-sided adhesive tape, thereby laminating the two plates 12a and 12b and punching them to the required size and shape. And pressing.

A first aspect of the present invention shown in Figure 2 is a urethane double-sided adhesive tape of a five-layer structure. Two sheets of 15 μm urethane composite resin films 21a and 21b each prepared by coating a urethane composite resin solution containing a curing agent on a release paper or a release film, drying and curing, were first laminated with an adhesive 20a, and then a urethane composite resin. Transfer coating of the polymer adhesive (20b, 20c) on both sides of the film (21a, 21b), and using a double-sided release paper or a release film to produce a double-sided adhesive tape in a roll, one plate (iron plate, glass plate, acrylic plate, etc.) (20a 2 sides of the plate 20a, 20b by attaching one side of the sheet to the adhesive 20b coated on one side of the double-sided adhesive tape, and attaching one side of the other plate 20b to the adhesive 20c on the other side of the double-sided adhesive tape. Are laminated and punched and pressed to the required size and shape.

Hereinafter, the present invention will be described in more detail through examples. However, these examples merely illustrate aspects of the invention and should not be construed as limiting the scope of the invention.

Example 1

After dispersing 5% γ-Fe ₂ O ₃ , 3% talc and 2% carbon black in urethane resin, 3% TDI was added to roll coating 25 μm on the release paper, dried and cured at 120 ° C. After preparing in sheet form, transfer-coating the adhesive (40% acrylic resin, 58% organic solvent, 1% TDI and 1% tetraglycidyl xylene diamine) on both sides by 40 μm, and then aged at 60 ° C. for 15 hours. After pressing and punching two sheets of stainless steel plate of 2 mm thickness, the noise / vibration blocking property (test method KSC1502 / 1507) and solvent resistance by TCE solvent cleaning for solvent resistance test were evaluated. In addition, adhesive force (test method: KS A1107), holding force (test method: KS A1107 ), initial adhesive force (test method: JIS K6714), and surface resistance (test method: ASTM D257) were measured.

Example 2

After dispersing 5% γ-Fe ₂ O ₃ , 3% talc and 2% carbon black in the urethane resin, 3% TDI was added, roll coating 15 μm on the release paper, drying and curing at 120 ° C. After making a sheet form and coating the adhesive (40% acrylic resin, 58% organic solvent, 1% TDI and 1% tetraglycidyl xylene diamine) on one side and dried, after laminating the two sheets, After transfer coating the adhesive on both sides by 40 μm, aged at 60 ° C. for 15 hours, two sheets of 2 mm thick stainless steel were laminated, pressed and punched, and then subjected to the same test method as described in Example 1. Noise / vibration barrier properties, solvent resistance, adhesion, holding force, initial adhesion, and surface resistance were measured.

Comparative Example 1

TDI 3% was added to the urethane resin in a roll coating of 25 μm on a release paper, dried and cured at 120 ° C. to prepare a sheet, and an adhesive was prepared and tested on both sides as in Example 1.

Comparative Example 2

After adding 3% of TDI to the urethane resin, roll coating of 15 μm on the release paper, drying and curing at 120 ° C. to prepare a sheet, and coating and drying the adhesive on one side of 20 μm, after laminating two sheets, The pressure-sensitive adhesive on both sides was prepared and tested as in Example 2.

The experimental results are shown in Table 1 below.

Item Example 1 Example 2 Comparative Example 1 Comparative Example 2 noise 18 dB 15 dB 24 dB 21 dB vibration 40 dB 35 dB 50 dB 45 dB Solvent resistance Good Good Elution Elution Surface resistance 108 108 1015 1015 Adhesive force (g / 25 mm) 1870 1800 1880 1800 Holding force (90 ℃ x120 minutes) Good Good 2 mm jungle 2 mm jungle

In the above examples and comparative examples, the double-sided adhesive tape according to the present invention has excellent noise and vibration blocking effect, and has a low surface resistance, which is excellent in the ability to remove static electricity. And it has excellent adhesion, holding strength and solvent resistance.

1 is a first embodiment in which two plates are laminated by a double-sided adhesive tape for pressing according to the present invention.

2 is a second embodiment in which two plates are laminated by a double-sided adhesive tape for pressing according to the present invention.

<Explanation of symbols for the main parts of the drawings>

10a, 10b, 20a, 20b, 20c adhesive

11, 21a, 21b urethane composite resin

12a, 12b, 20a, 20b plates

Claims (5)

Double-sided adhesive tape characterized in that the adhesive is coated on both sides of the urethane composite resin and the release paper or the release film is attached to the back side. The double-sided adhesive tape according to claim 1, further comprising an additional urethane composite resin layer and an adhesive layer. The method according to claim 1 or 2, wherein the urethane composite resin is mixed with a polyol of 5 to 30% by weight of γ-Fe ₂ O ₃ and Ba-ferrite, and 1 to 20% by weight of carbon black and talc 1 Double-sided pressure-sensitive adhesive tape, characterized in that to prepare a sheet by coating on a release paper or a release film by adding a curing agent of 10% by weight. The double-sided adhesive tape according to claim 1 or 2, wherein the thickness of each urethane composite resin layer is 5 to 100 µm and the thickness of each pressure-sensitive adhesive layer is 0.01 to 2 mm. The pressure sensitive adhesive according to claim 1 or 2, wherein the pressure sensitive adhesive comprises 20 to 50% by weight of a main monomer consisting of 2-HEA, VA, MA, EA, and MMA (hereinafter, based on the total weight of the pressure sensitive adhesive) and AA, HEMA, HEA, and MMA. Acrylic resin mixed with 1 to 10% by weight of functional monomer, 0.1 to 5% by weight of isocyanate and curing agent mixed with 0.1 to 3% by weight of tetraglycidyl xylenediamine and mixed with ethylene acetate, toluene and hexane Double-sided adhesive tape, characterized in that consisting of 50 to 70% by weight of the co-solvent.