A PRESSURE SENSITIVE ADHESIVE TAPE

Abstract

The pressure sensitive adhesive tape is superior in moisture resistance because of its high peel strength and is easy to peel from an adherend by including a filler in the adhesive layers.

Claims

1. A pressure sensitive adhesive tape, comprising a substrate layer and adhesive layers laminated on both faces of the substrate layer, wherein the thickness of the substrate layer is 25 μm to 500 μm and the substrate layer comprises a thermoplastic synthetic rubber and a reinforcement, the thickness of each adhesive layer is 10 μm to 240 μm respectively and the substrate layer comprises a thermoplastic synthetic rubber and a filler, the filler is a particle having the diameter of 0.01 μm to 120 μm, and the peel strength of the pressure sensitive adhesive tape is 6,000 to 25,000 gf/20 mm.

2. The pressure sensitive adhesive tape according to claim 1, wherein the filler is made of a glass, a metal, an inorganic particle, aluminum hydroxide, polyethylene, or polypropylene.

3. The pressure sensitive adhesive tape according to claim 1, wherein the content of the filler is 5 to 15 wt % per the total weight of the adhesive layer.

4. The pressure sensitive adhesive tape according to claim 1, wherein the peel strength of the pressure sensitive adhesive tape is 10,000 to 24,000 gf/20 mm.

5. The pressure sensitive adhesive tape according to claim 1, wherein the stretch release strength of the pressure sensitive adhesive tape is 3,000 gf or less.

6. The pressure sensitive adhesive tape according to claim 1, wherein the adhesive layers laminated on both sides of the substrate layer has the chemical compositions equal to or different from each other, the adhesive powers equal to or different from each other, the thicknesses equal to or different from each other, or the colors equal to or different from each other.

7. The pressure sensitive adhesive tape according to claim 1, wherein the reinforcement is fumed silica or titanium oxide.

8. The pressure sensitive adhesive tape according to claim 1, wherein the content of the reinforcement is 5 to 15 wt % per the total weight of the substrate layer.

9. The pressure sensitive adhesive tape according to claim 1, wherein the elongation of the pressure sensitive adhesive tape is 1,500 to 3,500%.

10. The pressure sensitive adhesive tape according to claim 1, wherein the tensile strength of the pressure sensitive adhesive tape is 1 MPa to 10 MPa.

11. The pressure sensitive adhesive tape according to claim 1, wherein the substrate layer has the structure in which 1 to 6 partial substrate layers of 25 μm to 85 μm thickness are laminated.

12. The pressure sensitive adhesive tape according to claim 1, wherein the adhesive layer has the structure in which 1 to 3 partial adhesive layers of 10 μm to 80 μm thickness are laminated.

13. The pressure sensitive adhesive tape according to claim 1, wherein the thermoplastic synthetic rubber is a polystyrene copolymer.

14. The pressure sensitive adhesive tape according to claim 13, wherein the polystyrene copolymer comprises a polybutadiene block or a polyisoprene block in addition to a polystyrene block.

15. The pressure sensitive adhesive tape according to claim 1, wherein the substrate layer or the adhesive layer further comprises one or more additives selected from the group consisting of a tackifier, a UV stabilizer, an antioxidant, and a toning agent.

16. The pressure sensitive adhesive tape according to claim 1, wherein the pressure sensitive adhesive tape further comprises a non-adhesive tap which covers part of the surface of at least one adhesive layer.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0054] FIG. 1 is a schematic drawing illustrating the structure and the principle of the pressure sensitive adhesive tape of the present invention.

DETAILED DESCRIPTION OF THE EMBODIMENT

[0055] Hereinafter, preferable examples and comparative examples are presented for understanding the present invention. However, the following examples are only for illustrating the present invention and the present invention is not limited to or by them.

EXAMPLES

[0056] Step 1) Preparation of Partial Substrate Layers

[0057] After mixing 11.4 g of Vector 4411A, 45.6 g of Vector 4113A, 43 g of tackifier (Haritack PH), 1 g of antioxidant (Irganox® 1010), 1 g of UV stabilizer (Tinuvin 477), 0.5 g of oil-based toning agent (white), 10 g of hydrophobic dry silica (AEROSIL® R 972), 7 g of titanium oxide (COTIOX KA-100), and 85 g of toluene, the partial substrate layer 1 having the thickness of 75 μm was prepared from the mixture by a hot air drying method.

[0058] Furthermore, the partial substrate layers 2 to 4 were prepared by the same method above, except changing their composition ratios as illustrated in the following Table 1.

TABLE-US-00001 TABLE 1 Partial substrate layers 1 2 3 4 Vector 4411A 11.4 g 60 g 10.6 g 31.8 g Vector 4113A 45.6 g — 42.4 g 21.2 g Haritack PH 43 g 40 g 47 g 47 g Irganox 1010 1 g 1 g 1 g 1 g Tinuvin 477 1 g 1 g 1 g 1 g Oil-based 0.5 g 0.5 g 0.5 g 0.5 g toning agent (white) (white) (white) (white) AEROSIL R972 10 g 10 g 10 g 10 g COTIOX KA-100 7 g 7 g 7 g 7 g Toluene 85 g 65 g 70 g 70 g

[0059] Step 2) Preparation of Partial Adhesive Layers

[0060] After mixing 45 g of SIS 1221, 55 g of tackifier (Haritack PH), 1 g of antioxidant (Irganox® 1010), 1 g of UV stabilizer (Tinuvin 477), 0.05 g of oil-based toning agent (blue), 10 g of aluminum hydroxide (BF 083), and 85 g of toluene, the partial adhesive layer 1 having the thickness of 85 μm was prepared from the mixture by a hot air drying method.

[0061] Furthermore, the partial adhesive layers 2 to 4 were prepared by the same method above, except changing their composition ratios as illustrated in the following Table 2.

TABLE-US-00002 TABLE 2 Partial adhesive layers 1 2 3 4 SIS1221 45 g 38 g 45 g 40 g Haritack PH 55 g 62 g 55 g 60 g Irganox 1010 1 g  1 g  1 g  1 g Tinuvin 477 1 g  1 g  1 g  1 g Oil-based 0.05 g  3 g  3 g  3 g toning agent (blue) (white) (white) (white) BF083 10 g 10 g 10 g  5 g Toluene 85 g 70 g 70 g 70 g

[0062] Step 3) Preparation of Pressure Sensitive Adhesive Tapes

[0063] After preparing a substrate layer by laminating the partial substrate layers, the pressure sensitive adhesive tapes were prepared by laminating the partial adhesive layers on both faces of the substrate layer as disclosed in the following Table 3.

TABLE-US-00003 TABLE 3 Thickness of the Adhesive layer Substrate layer layers Example 1 Partial adhesive layer 1 Partial substrate layer 1 640 μm (75 μm × 4) (85 μm × 2) Example 2 Partial adhesive layer 2 Partial substrate layer 2 640 μm (75 μm × 4) (85 μm × 2) Example 3 Partial adhesive layer 3 Partial substrate layer 3 640 μm (75 μm × 4) (85 μm × 2) Example 4 Partial adhesive layer 4 Partial substrate layer 4 640 μm (75 μm × 4) (85 μm × 2)

Comparative Examples

[0064] The pressure sensitive adhesive tapes of Comparative Examples 1 to 4 were prepared by the same method as in Example above, except that the filler (BF083) was not used in the preparation of the partial adhesive layer.

Experimental Example

[0065] The properties of the pressure sensitive adhesive tapes prepared in Example were measured by the following methods.

[0066] 1) Measurement of 180° Peel Strength

[0067] The pressure sensitive adhesive tape was cut into 20 mm width and a PET film of 25 μm thickness was attached to the opposite face of the measuring face thereof. The measuring face of the pressure sensitive adhesive tape was attached to a SUS adherend and the film was pressed by rolling a 2 kg roller back and forth once thereon. After 30 mins passed, the peel strength was measured by peeling the film 180° with the speed of 300 mm/min. At this time, the measurement was carried out by using a universal testing machine (UTM, LR5K plus of AMETEK company Co., Ltd.).

[0068] 2) Measurement of Tensile Strength and Elongation

[0069] The pressure sensitive adhesive tape was cut into 20 mm×60 mm size and both ends of the same were clamped in the UTM so that the measuring part where substantial deformation occurred was 20 mm×20 mm size. The tensile strength and the elongation were measured by pulling the tape with the speed of 300 mm/min.

[0070] 3) Comparison of Stretch Release Strength (Removability)

[0071] The pressure sensitive adhesive tape was cut into 20 mm×60 mm size and glass adherends were attached to both faces of the measuring part of 20 mm×40 mm. After 30 mins passed, the upper part (20 mm×20 mm) of the pressure sensitive adhesive tape was clamped in the UTM and the force when the pressure sensitive adhesive tape was peeled between the glass adherends was measured.

[0072] 4) Test of Moisture Resistance

[0073] The pressure sensitive adhesive tape was cut into 25 mm×25 mm size and attached to a SUS adherend by rolling a 2 kg roller back and forth once thereon. Subsequently, the specimen was loaded by a 1 kg weight and left in a thermo-hygrostat of 35° C. and 90% RH condition for 500 hrs. After eliminating the weight, whether the specimen was dropped out from the SUS adherend or not was checked.

[0074] The results of the measurements are listed in the following Table 4.

TABLE-US-00004 TABLE 4 Stretch release strength test (gf) Before adding After adding Tensile filler filler Peel strength strength Elongation (Comparative (Examples 1 Moisture (gf/20 mm) (MPa) (%) Examples 1 to 4) to 4) resistance Example 1 16,000 4.74 2800 3140 2600  pass.sup.1) Example 2 20,000 5.41 1700 3320 2850 pass Example 3 16,500 4.90 3200 3180 2690 pass Example 4 19,000 5.30 1700 3230 2800 pass .sup.1)pass: specimen was not dropped out from the SUS adherend

[0075] As shown in Table 4, the pressure sensitive adhesive tapes according to the present invention were not dropped out in the moisture resistance test because their peel strength was high. Furthermore, in comparison to the pressure sensitive adhesive tapes of Comparative Examples to which the filler was not added, it is recognizable that the pressure sensitive adhesive tapes according to the present invention show low stretch release strength, specifically, less than 3,000 gf, and are easy to peel.

[0076] Therefore, it is recognizable that the pressure sensitive adhesive tape according to the present invention is superior in moisture resistance because of its high peel strength and is easy to eliminate because of it low stretch release strength due to addition of the filler.