JP2003020460A - Double-faced adhesive tape free from releasing liner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a double-faced adhesive tape free from a releasing liner and produced by using a strong and tough paper as the substrate. SOLUTION: A paper substrate 1 is produced by using a pulp composition composed of 30-65% short fiber pulp, 10-55% kraft pulp, 5-20% synthetic pulp such as polyester and 10-40% long fiber pulp taking the total pulp composition as 100%. The double-faced adhesive tape 4 free from a releasing liner is produced by forming a tacky adhesive layer 2 on one surface of the paper substrate, forming an adhesive layer 3 releasable from the tacky adhesive layer 2 on the reverse side of the paper substrate and winding the product. A waste paper pulp can be used as the short fiber pulp. The double-faced adhesive tape 4 free from a releasing liner is cleanly releasable at the interface of both adhesive layers without causing the delamination of the substrate and is cleanly peelable also from an adherend.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to a paper-based, non-release liner-double sided adhesive tape.

[0002]

2. Description of the Related Art When a nameplate, a poster or the like is attached and fixed, the adhered portion is not necessarily a smooth surface but is often a rough surface. With double-sided adhesive tape made of plastic film or non-woven fabric as the base material, increasing the thickness of the base material causes sawtooth cutters.
Since it can not be easily cut with, only a thin base material can be made, and if such a double-sided adhesive tape is used, sufficient adhesion can be obtained due to lack of thickness. It may not be possible, and fixing may be insufficient.

Paper is effective as a base material for a double-sided adhesive tape which has a sufficient thickness, is flexible, and is easy to cut. However, the paper-based material has a low internal strength, so when the material wound in a roll is unwound, the base material internally breaks and the middle of the base material layer is broken. There is a disadvantage that it cannot be used as a double-sided adhesive tape because it tears and peels off.

[0004]

The inventors of the present invention have conducted various studies on non-release liner-double-sided adhesive tape, and when short fiber pulp is mixed in pulp, the inside of the paper substrate is The inventors have found that a double-sided pressure-sensitive adhesive tape having increased strength, toughness, and flexibility can be obtained, and completed the present invention.

[0005]

DISCLOSURE OF THE INVENTION According to the present invention, a short-type pulp, a kraft pulp, a synthetic pulp, and a long-fiber pulp are mixed to form a paper base material, and another type of pressure-sensitive adhesive which can be peeled on both sides of the base material. A layer is formed into a non-release liner-double-sided adhesive tape. The above-mentioned paper base material is short fiber pulp 30 to 65% (weight%;
The same shall apply hereinafter), Kraft pulp 10-55%, Synthetic pulp 5-
20%, 10-40% long fiber pulp,
Try to be 100%. The short fiber pulp is preferably a mixture of fibers having a fiber diameter of 5 to 35 μm and a fiber length of 0.5 to 4 mm, and waste paper pulp can be used as such a short fiber pulp.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION There are short fiber pulp, kraft pulp, synthetic pulp, and long fiber pulp as the components forming the base material of the double-sided adhesive tape. The short fiber pulp has a fiber diameter of about 5 to 35 μm and a fiber length of about 0.5 to 4 mm. Kraft pulp has an average fiber diameter of about 40 μm and an average fiber length of about 4 to 5 mm. Synthetic pulp is a pulp formed from polyvinyl alcohol, polyester or other synthetic resin, and has an average fiber diameter of about 16 μm and an average fiber length of about 4 to 5 mm. Has an average fiber diameter of about 45
The average fiber length is about 5 to 6 mm. The short fiber pulp is 30 to 65%, the kraft pulp is 10 to 55%, the synthetic pulp is 5 to 20%, the long fiber pulp is 10 to 40%, and the total fiber content is 100%. To do.

The above-mentioned short fiber pulp has a small fiber diameter, a medium diameter, a thick one, a short fiber length, a medium fiber length, and a fiber diameter smaller than those concentrated in a narrow portion within the above range. It is preferable that long ones are variously combined to have a wide distribution and mixed various diameters and lengths. As the short fiber pulp, it is more preferable to use one in which fibrils are formed on the surface by further beating a normal pulp, and waste paper pulp can be used as such.
Since the waste paper pulp is one in which virgin pulp is once used as paper and then beaten to be made into paper again, various fiber diameters and fiber lengths are mixed, and the above fibrils are also effective, so it is effective. Can be used for

Due to the short fiber pulp distributed over such a wide range, the fibrils are entangled with each other during the papermaking process, and the constituent pulp fibers are strongly bound to each other to increase the internal strength of the base material. The use of short fiber pulp tends to reduce air permeability and permeability, but since thin and long synthetic pulp and thick and long long fiber pulp are also mixed, toughness also increases and there is also a necessary thickness. , A proper gap will also be generated. Since each adhesive formed on both sides of the base material also penetrates through the gaps, the strength of the base material is further increased and the base material is less likely to be torn or broken. The thickness of the paper base material is about 40 to 85 μ, preferably about 50 to 80 μ, and the basis weight is about 20 to 60 g / m ² , preferably about 30 to 50 g / m ^2. It should be about m ² .

If the above base material is impregnated with a resin in advance, the internal strength of the base material can be further increased to ensure the reliability. As the impregnating agent, acrylic ester resin,
Urethane resin, styrene-butadiene rubber (SB
R), acrylonitrile-butadiene rubber (NBR),
Butyl rubber, polyisobutylene, and other resins can be used, and those having a glass transition temperature of 25 ° C. or lower are preferable. If the glass transition temperature is high, the tear strength will decrease, the anchoring property of the adhesive to the base material will decrease, and the adhesive will remain on the adhered site when peeling off the double-sided adhesive tape that has been applied. .

The coating amount of the impregnating agent is preferably about 6 to 30 g / m ² , and preferably about 10 to 20 g / m ² . It is preferable to determine the coating amount of the impregnating agent by the air permeability of the base material coated with the impregnating agent (JIS P-8117: represented by the time required for 100 ml of air to pass through an area of 645 mm ² ). The temper is preferably 3 seconds or less. The application of the impregnating agent can make the surface of the pressure-sensitive adhesive layer in contact with the surface smooth and improve the anchoring force of the pressure-sensitive adhesive.

For the pressure-sensitive adhesive layers 2 and 3 formed on both sides of the base material 1, rubber-based, acrylic-based, or other pressure-sensitive adhesives can be used depending on the application. For such cases, it is often convenient to use an acrylic adhesive.

The pressure-sensitive adhesive layer 2 provided on one surface of the base material of the non-peeling liner-double-sided tape 4 and the pressure-sensitive adhesive layer 3 provided on the other surface are overlapped when wound, A pressure-sensitive adhesive having a slightly different pressure-sensitive adhesive property is used so that it can be peeled off at the interface between both pressure-sensitive adhesive layers 2 and 3 when returned.

The above-mentioned rolled non-release liner paper double-sided adhesive tape has a rewinding force when rewound.
Approximately with 15mm width tape under rewinding condition of 1000mm / min.
It is preferable to set it to about 0.5 to 12 N, preferably about 3 to 10 N. The measurement of this unwinding force is
JISZ0 except that the rewind speed is set to 1000 mm / min.
It carried out according to 237.

The above-mentioned non-release liner paper double-sided adhesive tape is wound around a winding core and wound, and a silicone-based UV-curable resin is applied to both sides of the tape to irradiate ultraviolet rays, or an alkyl-based emulsion or the like. When the anti-adhesion treatment to prevent stickiness due to the adhesive by applying the anti-adhesion agent of
Handling becomes easier.

[0015]

(Example) (Example 1) Short fiber pulp (waste paper pulp) 50
%, Kraft pulp 20%, vinylon pulp 10%, and long fiber pulp 20% to form a paper having a thickness of 70 μ as a base material. Composition of 2-ethylhexyl acrylate 92%, vinyl acetate 5%, acrylic acid 3%, weight average molecular weight 90
In the meantime, an acrylic pressure-sensitive adhesive to which an appropriate amount of a cross-linking agent was added was laminated on one surface of the above base material to a thickness of 50 μm by a transfer method to form a pressure-sensitive adhesive layer. Further, on the other surface of the above-mentioned substrate, an acrylic pressure-sensitive adhesive having a composition of butyl acrylate 92%, vinyl acetate 5%, acrylic acid 3%, a weight average molecular weight of 950,000, and an appropriate amount of a crosslinking agent added, Similarly, a pressure-sensitive adhesive layer was formed by laminating to a thickness of 50 μm by the transfer method. This double-sided adhesive tape
Aged at 40 ° C for 3 days, and put this on a core with an outer diameter of 82 mm and a width of 15 mm.
The tape was wound for 18 m to obtain a non-peeling liner-double-sided adhesive tape.

(Comparative Example 1) Short fiber pulp (waste paper pulp)
Paper having a thickness of 70 μ was formed as a base material by a composition ratio of 0%, kraft pulp 70%, vinylon pulp 10%, and long fiber pulp 20%. Others were the same as in Example 1 above.

(Comparative Example 2) Short fiber pulp (waste paper pulp)
Paper having a thickness of 70 μ was formed as a base material by the composition ratio of 75%, kraft pulp 0%, vinylon pulp 10%, and long fiber pulp 15%. Others were the same as in Example 1 above.

(Test) Ten pieces of each of the above-mentioned Example 1, Comparative Example 1 and Comparative Example 2 were prepared, and the above-mentioned 1000 mm / mi was prepared.
It was rewound at a speed of n.

(Results) Example 1; For all of the 10 pieces, the base material was able to be peeled off at the interface of both adhesive layers without cracking. The unwinding force was 8.5N. Comparative Example 1; 9 out of 10 cracked base materials and could not be used as a tape. Comparative Example 2 Regarding 9 out of 10, the base material was broken and could not be used as a tape.

(Example 2) Short fiber pulp (waste paper pulp)
Paper having a thickness of 70μ was formed by the composition ratio of 45%, kraft pulp 30%, vinylon pulp 10%, and long fiber pulp 15%.
This was impregnated with an impregnating agent having a glass transition temperature of −45 ° C. with a mixture of butyl rubber and a phenol resin, and the air permeability was 2.1.
A second substrate was created. On one side of this substrate, 2-ethylhexyl acrylate 85%, vinyl acetate 10%, acrylic acid 5%
%, An acrylic pressure-sensitive adhesive having a weight average molecular weight of 850,000 and an appropriate amount of a crosslinking agent was laminated to a thickness of 50 μm by a transfer method to form a pressure-sensitive adhesive layer. On the other surface of the base material,
A composition of 85% butyl acrylate, 10% vinyl acetate, 5% acrylic acid, a weight average molecular weight of 950,000, and an acrylic adhesive with an appropriate amount of cross-linking agent was also applied by the transfer method.
A pressure-sensitive adhesive layer was formed by laminating it to a thickness of μ. This double-sided adhesive tape was wound around a core having an outer diameter of 82 mm with a width of 15 mm for 18 m to obtain a non-peeling liner double-sided adhesive tape.

Example 3 An acrylic emulsion having a glass transition temperature of −48 ° C. was used as an impregnating agent.
A substrate with an air permeability of 1.8 seconds was created. Others were the same as in Example 2 above.

Comparative Example 3 A vinyl acetate / acrylic acid copolymer resin having a glass transition temperature of 45 ° C. was used as an impregnating agent, and a substrate having an air permeability of 1.9 seconds was prepared. Others were the same as in Example 2 above.

(Test) Ten of each of the above-mentioned Example 2, Example 3, and Comparative Example 3 were prepared, stored at 40 ° C. for 10 days, and then rewound at the above-mentioned speed of 1000 mm / min. It was

(Results) Example 2; 10 out of 10 did not change the base material and could be peeled off at the interface of both adhesive layers. Unwind force is 8.7
It was N. Example 3; 10 out of 10 could be peeled off at the interface of both pressure-sensitive adhesive layers without causing cracking of the substrate. The unwinding force was 5.6N. Comparative Example 3: About 9 out of 10 pieces, the base material caused internal destruction, and the base material was broken, so that it could not be used as a tape.

(Discussion) Good results were obtained in Examples 1 to 3, and in the case where the impregnating agent of Examples 2 and 3 was applied, the paper base material was further stabilized and the adhesive base material against the base material. It can be seen that the anchoring property has also improved. On the other hand, in Comparative Example 1, since the short fiber pulp is not used as the paper base material, the internal strength of the base material is low, internal destruction occurs and peeling occurs in the intermediate layer. In Comparative Example 2, Since the ratio of the short fiber pulp is large, the internal strength of the base material is high, but it is considered that the base material is torn due to poor toughness. Further, in Comparative Example 3, it can be seen that the base material causes internal destruction because the glass transition temperature of the impregnating agent applied to the base material is high.

[0026]

As described above, according to the present invention, the base material of the non-release liner-double-sided adhesive tape is composed of short fiber pulp, kraft pulp, synthetic pulp and long fiber pulp in a predetermined composition ratio. High internal strength and rich toughness,
A strong and durable substrate can be economically obtained. The base material is not destroyed even when it is rewound and peeled again, and it can be peeled off neatly at the interface between both adhesive layers,
It is easy to use and a preferable double-sided adhesive tape for paper can be obtained. Then, it can be peeled off cleanly from the adherend to which it is attached. Further, a better double-sided adhesive tape can be obtained by applying an impregnating agent having a low glass transition temperature such as an acrylic emulsion to the above base material.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention.

FIG. 2 is a partially enlarged cross-sectional view of FIG.

[Explanation of symbols]

1 base material 2,3 adhesive layer 4 Paper double-sided adhesive tape

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 4J004 AA05 AA10 AB01 CA03 CB01                       CB02 CC02 CD02 EA01 EA03                       EA05 FA08                 4L055 AA11 AC06 AC09 AF13 AF21                       AG64 AG71 AG76 AG79 AG89                       AH16 AH37 AH50 AJ01 AJ03                       EA04 EA08 EA16 FA13 FA16                       FA22 GA42 GA50

Claims (8)

[Claims] 1. Short fiber pulp 30 to 65%, kraft pulp
10-55%, synthetic pulp 5-20%, long fiber pulp 10-40%
A paper base material containing as a composition, a pressure-sensitive adhesive layer is provided on one surface of the paper base material, and a pressure-sensitive adhesive layer that can be peeled from the pressure-sensitive adhesive layer on the other surface is formed on the other surface of the paper base material. Adhesive tape. 2. The short fiber pulp has a fiber diameter of 5 to 35 μm.
2. The non-release liner double-sided adhesive tape according to claim 1, wherein fibers having a fiber length of 0.5 to 4 mm are mixed.
Pu. 3. The average fiber diameter of the kraft pulp is 40 μm.
The average fiber length is 4 to 5 mm, the average fiber diameter of synthetic pulp is 16 μ and the average fiber length is 4 to 5 mm, and the average fiber length of long fiber pulp is 45 μ and the average fiber length is 5 to 6 mm. Item 2. The non-release liner double-sided adhesive tape according to Item 1 or 2. 4. The non-release liner double-sided adhesive tape according to claim 1, wherein the short fiber pulp is formed of waste paper pulp. 5. The paper base material has a thickness of 40 to 85 μm and a basis weight of
The release-free liner double-sided adhesive tape according to any one of claims 1 to 4, which has a weight of 20 to 60 g / m ² . 6. The non-release liner double-sided adhesive tape according to claim 1, wherein the paper base material is impregnated with a resin having a glass transition temperature of 25 ° C. or lower. 7. The rewinding force of the rolled non-release liner double-sided adhesive tape is 0.5 N to 12 N when rewound on a 15 mm wide tape at 1000 mm / min.
6. The release-free liner double-sided adhesive tape according to any one of 6 above. 8. The non-release liner double-sided pressure-sensitive adhesive tape according to claim 1, wherein both sides of the wound double-sided pressure-sensitive adhesive tape are subjected to an adhesion preventing treatment for preventing stickiness.