JP3074947B2 - Double-sided adhesive tape for attaching rubbing cloth - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a double-sided adhesive tape for attaching a rubbing cloth used in a liquid crystal panel manufacturing process.

[0002]

2. Description of the Related Art Double-sided adhesive tapes are used in combination with the base material, the adhesive material, the thickness of the adhesive, and the like, depending on the intended use.
Many have different characteristics.

[0003] The base material of the double-sided adhesive tape includes types of plastic films such as polyester, polypropylene and vinyl chloride, non-woven fabric, Japanese paper and foam.

A pressure-sensitive adhesive made of a synthetic resin is used as an adhesive formed on one or two surfaces of a base material.

Conventional double-sided adhesive tapes for rubbing cloth are:
One substrate and two substrates have the same adhesive strength on one surface and two
The adhesive strength of the surface is changed, the rubbing cloth is adhered with the stronger adhesive strength, and the adhesive strength of the weaker adhesive strength is adhered to the rubbing roller. Some are formed thicker than the adhesive layer on the roller side.

[0006]

The pressure-sensitive adhesive material used for the double-sided adhesive tape has a large difference in the adhesive strength depending on the applied pressure and the effective adhesive area.

[0007] The base material has an appropriate thickness to the tape, and has a property of easily securing an effective adhesive area at the time of pressure bonding (generally, a flexible base material is used), a property of easily peeling, and a property of transparency (general). (A plastic substrate having a strong substrate) is used, and the adhesive strength can be varied depending on the type of the substrate.

In a rubbing step in a liquid crystal panel manufacturing process,
There is an operation of attaching a rubbing cloth to a rubbing roller. The mainstream of the attaching method is an attaching method using a double-sided adhesive tape.

The structure of the rubbing cloth as one of the adherends is as follows.
Woven yarn such as rayon, nylon, cotton, etc. is woven into W-shape or V-shape into a base fabric composed of woven yarn such as polyester for warp and weft, and weaving the warp and weft in a lattice. A back coating of a resin agent is formed from the back surface. For this reason, the adhesive surface of the rubbing cloth inherently has irregularities having a height h of about 0.1 to 0.5 mm caused by weaving of the bristle.

[0010] The bonding surface of the rubbing roller, which is the other adherend, is a very smooth surface because it is manufactured by precision machining.

The characteristics required of a double-sided adhesive tape for attaching a rubbing cloth are that the adhesive strength is required so that the number of rubbing treatments can be performed in accordance with a predetermined production number, and that the rubbing roller is manually replaced from the surface of the rubbing roller when replacing the rubbing cloth. It is easy to peel off, and has good workability with little adhesive remaining.

For example, in the case of a double-sided adhesive tape in which the base material is a non-woven fabric having flexibility and high adhesive strength and formed on one and two sides with an acrylic pressure-sensitive adhesive, the pressure-sensitive adhesive is often used as a base material. Impregnated into the material and adhere to the substrate with the thickness and softness of the substrate
It absorbs irregularities, so it is easy to secure an effective bonding area and the bonding strength is moderate, but it is very difficult to peel off once again (removability) once it is applied due to its poor base strength and base stretchability. . This double-sided adhesive tape is suitable for bonding to irregularities such as the rubbing cloth bonding surface , and has an adhesive strength that enables the number of rubbing treatments according to the specific production number. There is a problem that requires a lot of labor and time.

For this purpose, there is a method in which the rubbing roller is heated to a specific temperature to reduce the adhesive strength of the double-sided adhesive tape, thereby improving the workability of peeling. A problem that requires a heating facility occurs.

The base material is a plastic base material such as a polyester film or a polypropylene film,
A double-sided adhesive tape formed of an acrylic pressure-sensitive adhesive has inflexibility and poor cushioning properties, so it is difficult to secure an effective area for bonding to uneven surfaces. The adhesive strength to the body is hardly obtained, and the fabric is peeled off from the seam portion of the rubbing cloth until the predetermined number of rubbing treatments is reached, resulting in poor quality.

[0015] On the other hand, since it has the feature that the substrate strength and the substrate stretchability are excellent, the removability from the rubbing roller is satisfied. Therefore, there is also a double-sided adhesive tape in which the adhesive strength on the rubbing cloth side is made stronger than the adhesive strength on the rubbing roller side to secure the adhesive strength on the rubbing cloth side and to simultaneously obtain removability on the rubbing roller side. However, since the plastic substrate itself is inferior in flexibility, the rubbing cloth cannot be provided with an adhesive strength against the unevenness of the rubbing cloth bonding surface, and the rubbing cloth peels off as described above.

From the above, in the conventional double-sided adhesive tape configuration, the adhesion between the adherend having the uneven surface and the smooth adherend can provide sufficient adhesive strength to the uneven surface, and the tape can be peeled off again. It is difficult to simultaneously satisfy satisfactory characteristics and achieve a predetermined number of rubbing treatments.

In view of the above, an object of the present invention is to provide a double-sided adhesive tape which does not cause the above-mentioned problems.

[0018]

In order to solve the above-mentioned problems, a first base material having flexibility, a second base material having stretchability, and three adhesive layers are provided. A first base material having flexibility is sandwiched between the second adhesive layers, and a second base material having extensibility is sandwiched between the second adhesive layer and the third adhesive layer, and are combined into a laminate. A means having the above configuration is used.

Based on the above-mentioned means, a double-sided adhesive tape having an adhesive formed on one and two sides of a nonwoven fabric base and a double-sided adhesive tape having an adhesive formed on one and two sides of a plastic base are bonded together. Using the combined double-sided adhesive tape for applying a rubbing cloth, the double-sided adhesive tape side formed of a nonwoven fabric substrate is attached to the rubbing cloth side, and the double-sided adhesive tape side formed of a plastic base material is attached to the rubbing roller side.

[0020]

The surface of the rubbing cloth bonded surface, which is one of the adherends, has irregularities of about 0.1 to 0.5 mm. Further, the rubbing cloth is a woven fabric, does not have planar accuracy as in the case of machining, and has unevenness in height. In addition, since it is coated with a resin agent for the purpose of preventing the rubbing cloth from coming off and imparting the strength of the base cloth, it is hard and does not have the flexibility of a normal cloth.

In order to secure the adhesive strength of such an uneven surface, it is important how large an effective adhesive area can be obtained. In other words, the contact between the adhesive layer of the double-sided adhesive tape and the rubbing cloth bonding surface is not a surface contact but a collection of point contacts. It is necessary to obtain a high anchoring effect of bonding by making the adhesive layer bite more during the bonding. Since the base material of the double-sided adhesive tape adds a function to make it easy to secure the effective bonding area during pressure bonding, the anchoring effect of bonding differs depending on the material properties of the base material, and there is a large difference in bonding strength and removability. .

However, the height variation of the unevenness is absorbed,
In order to make the double-sided adhesive tape deeply bite the convex part with the applied pressure, use a nonwoven fabric, Japanese paper, or a base material made of foam that has more flexibility than increasing the adhesive strength of the double-sided adhesive tape. By digging the protrusions into the base material, the adhesive layer penetrates deeply between the protrusions and increases the anchoring effect of bonding, so it is easy to think that adhesive strength to the uneven surface can be obtained. Can be

On the other hand, the rubbing roller, which is the other adherend, is manufactured by precise mechanical cutting, so that the surface roughness is low.
A certain degree there. Assuming the surface roughness of the machined object as a collection of countless low V-grooves, the double-sided adhesive tape with flexibility cuts into countless V-grooves, resulting in a higher anchoring effect of bonding, Obtain stronger adhesive strength. Since the rubbing roller is recycled, the rubbing cloth is replaced.
At this time, the removability of the double-sided adhesive tape largely depends on the workability of cloth replacement. When a flexible substrate is used, when peeled from the rubbing roller, the peeling adhesive strength is stronger than the tensile strength of the substrate, so the substrate is broken in the middle and there is no continuity in re-peeling, Problems that require a lot of effort and time.

In order to obtain the removability of the double-sided adhesive tape, a plastic substrate such as polypropylene, polyester, vinyl chloride or the like which has a substrate strength and an extensibility that can withstand the peeling adhesive strength is suitable. However, a plastic substrate having high strength and stretchability has a disadvantage that flexibility is inferior.On the other hand, the repulsion of the substrate acts strongly against the pressing force to be adhered, and the convex portion is deep in the substrate. Since it is difficult to bite, the thickness of the adhesive layer is only about 30 to 40 μm, and it is difficult to absorb the unevenness in height of the unevenness, so that a large effective bonding area cannot be obtained, and a predetermined required adhesive strength for unevenness cannot be obtained.

Therefore, the flexible base material is used as the first base material, the stretchable base material is used as the second base material, and the first base material and the second base material are bonded with the second adhesive layer. A base material that has been combined into a laminate is formed. Then, a first adhesive layer is formed on the surface of the first base material, and a third adhesive layer is formed on the surface of the second base material. By bonding an adherend having a surface, and by bonding an adherend having a smooth surface on the third adhesive layer side to the second substrate having a small anchoring effect and a strong substrate strength, Adhesive strength and removability on a smooth surface can be simultaneously obtained, and the required properties can be satisfied.

The rubbing cloth having irregularities is well impregnated with an adhesive and is held and held by a double-sided adhesive tape formed of a flexible nonwoven base material having a cushioning property.
Since it is fixed, a sufficient bonding effective area is secured, and a suitable bonding strength is obtained. On the other hand, a rubbing roller having a smooth surface is a plastic base material having a thin base material and a poor cushioning property, and a double-sided adhesive tape formed with an adhesive layer capable of sufficiently obtaining an adhesive strength with a smooth surface, Due to the strength of the plastic base material and the stretchability of the base material, a function with good removability satisfying the adhesive strength with the rubbing roller is obtained.

The double-sided adhesive tape formed by laminating and bonding two double-sided adhesive tapes formed from the base materials having the contradictory characteristics has a strong adhesive strength to the rubbing cloth and a removability from the rubbing roller. egoism,
The desired number of rubbing treatments can be reached.

The bonding between the nonwoven fabric substrate and the plastic substrate is the bonding between the adhesive layers, and a sufficient bonding strength can be obtained.
The substrate is not peeled off by the rubbing treatment load, and breakage or displacement due to the shearing action does not occur.

[0029]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a structural view of a double-sided tape according to one embodiment of the present invention, and FIG. 2 is a cross-sectional view showing a state in which a rubbing cloth is adhered to a rubbing roller.

First, the specifications of the double-sided tape used in the embodiment will be described. In FIG. 1, a first adhesive layer 2a and a second adhesive layer 2
b formed and second made of polypropylene
A double-sided adhesive tape for applying a rubbing cloth, which is obtained by laminating a third adhesive layer 4a and a fourth adhesive layer 4b on one surface and two surfaces of a base material 5 so as to be free of wrinkles and bubbles. 6 was produced. Then, in order to process the double-sided adhesive tape to a specific size, the separators 1a, 1b are respectively placed on the first adhesive layer 2a and the fourth adhesive layer 4b formed on the front and back surfaces of the double-sided adhesive tape 6 for applying a rubbing cloth. Was pasted. The adhesive used was an acrylic pressure-sensitive adhesive.

Next, a configuration for attaching a rubbing cloth to a rubbing roller will be described using this embodiment.

In FIG. 2, the separator 1b on the side of the second base material 5 of the double-sided adhesive tape 6 for applying a rubbing cloth processed to a specific size was peeled off and affixed to the outer peripheral surface of the rubbing roller 8 by the fourth adhesive layer 4b. Thereafter, the separator 1a on the first base material 3 side was peeled off, and the rubbing cloth 7 was stuck on the first adhesive layer 2a so as to prevent wrinkles while slightly pressing the rubbing cloth 7 from above.

A rubbing treatment comparison experiment was conducted with the above structure under a constant rubbing condition, and the results of evaluation of the conventional method based on the adhesive strength to the rubbing cloth and the removability from the rubbing roller are shown in Table 1. . The adhesive strength in Table 1 is a reference value in a manufacturer's catalog of a 180 ° peel adhesion test after 20 hours with respect to stainless steel.

The rubbing roller is made of aluminum.
The width of the adhesive double-sided tape was 25 mm, and the number of rubbing rollers to be attached was the same as 14 sheets.

The adhesive strength with the rubbing cloth is determined by comparing the number of rubbing treatments until the seam of the rubbing cloth is peeled off when the rubbing cloth is attached to the rubbing roller or the cloth is lifted off the adhesive. The goal was to achieve at least 150 times.

For removability from the rubbing roller, no post-treatment such as solvent immersion or heat treatment was performed, and the rubbing cloth was removed manually after the above-mentioned adhesive strength test. The operation time from the start of the peeling operation to the completion of the peeling of 14 double-sided adhesive tapes was compared.

[0038]

[Table 1]

In comparison with these conventional examples, in this embodiment, the number of times the rubbing process was performed before the seam was peeled off by the rubbing treatment load was 80 times or more at the maximum, and the work time for peeling the double-sided adhesive tape from the rubbing roller was large. However, a significant time reduction from 16 hours to 3 minutes was achieved. Furthermore, no peeling or destruction was observed at the bonding interface between the substrates. As described above, according to the present example, the adhesive strength to the rubbing cloth and the removability from the rubbing roller were simultaneously excellent, and the effect of reaching the target number of rubbing treatments was recognized.

In this case, the experiment was carried out with 14 double-sided adhesive tapes having a width of 25 mm and affixed to a rubbing roller with 14 rubbing rollers. It is clear that the effects of the adhesive strength to the rubbing cloth and the removability from the rubbing roller are further enhanced.

In this embodiment, the flexible substrate is limited to nonwoven fabric and the stretchable plastic substrate is limited to polypropylene. However, the flexible substrate is made of Japanese paper or foam, and the stretchable substrate is limited to nonwoven fabric. The same effect can be obtained by applying polyester, vinyl chloride or the like.

Further, the adhesive strength of the first adhesive layer was made stronger than the adhesive strength of the fourth adhesive layer to give a difference. However, the thickness of the pressure-sensitive adhesive material or the adhesive was changed depending on the adherend. By making the thickness of the material appropriate, the same effect can be obtained even if the first adhesive layer and the fourth adhesive layer have the same adhesive strength. Further, the second adhesive layer, the third adhesive layer, and the two adhesive layers were bonded between the first base material and the second base material. It may be affixed with an adhesive layer.

[0043]

As described above, according to the present invention, a substrate having flexibility and a substrate having stretchability are bonded with an adhesive to bond an adherend having irregularities and an adherend having a smooth surface. By applying a double-sided adhesive tape composed of a combined base material structure, it has the adhesive strength necessary for holding and fixing the adherend, has a strong adhesive strength on uneven surfaces, and has good removability on smooth surfaces. Two properties were obtained simultaneously.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a double-sided tape according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a state in which a rubbing cloth according to one embodiment of the present invention is attached to a rubbing roller.

[Description of Signs] 1a Separator 1b Separator 2a First adhesive layer 2b Second adhesive layer 3 First substrate 4a Third adhesive layer 4b Fourth adhesive layer 5 Second substrate 6 Double-sided adhesive for rubbing cloth application Tape 7 rubbing cloth 8 rubbing roller

────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-3-264926 (JP, A) JP-A-4-84123 (JP, A) JP-A-3-209428 (JP, A) JP-A 64-64 20349 (JP, A) JP-A-63-207881 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G02F 1/1337

Claims (2)

(57) [Claims] 1. A first base material having flexibility, a second base material having extensibility, and three adhesive layers, having flexibility between the first adhesive layer and the second adhesive layer. Sandwich the first base material,
A second extensible layer between the second adhesive layer and the third adhesive layer;
A structure in which coalesced into a product layered sandwich the substrate, the first
The first adhesive layer is a rubbing cloth side and the third adhesive layer is a rubbing cloth.
A double-sided adhesive tape for attaching a rubbing cloth, wherein the double-sided adhesive tape is on the side of a roller . 2. A double-sided adhesive tape in which an adhesive layer is formed on one and two surfaces of a nonwoven fabric substrate and one and two surfaces of a plastic substrate.
The double-sided adhesive tape on which the adhesive layer is formed is bonded and united, and the adhesive layer on the outer side of the nonwoven fabric substrate is rubbed.
The adhesive layer on the outside of the plastic substrate
A double-sided adhesive tape for applying a rubbing cloth, which is on the rubbing roller side .