JPH06322329A - Explosion-proof adhesive tape for orthoblend base material - Google Patents

Abstract

PURPOSE:To provide an inexpensive explosion-proof adhesive tape using, as base, an orthoblend with glass yarns woven as wefts, useful for preventing cathode-ray tubes from implosion, and having proof compressive breaking strength inherent in glass yarns and flexibility inherent in natural or synthetic fibers. CONSTITUTION:The objective explosion-proof adhesive tape so designed that a single side of a base material is provided with a pressure-sensitive tack agent layer and the opposite side with hot-melt type adhesive layer. The base material consists of an orthoblend using natural or synthetic fibers as warp component and, as weft component, eithter (A) glass yarns singly or (B) such blended yarns that glass yarns and natural or synthetic fibers of the same kina as the warp component are alternately or every several numbers woven. This adhesive tape has a lateral proof compressive breaking strength of >=5kgf/cm based on 0.5mm of mold match line difference in height. The natural or synthetic fibers are pref. 20-30S in single fiber count, while the glass yarns are pref. 50-200 denier in single fiber fineness. It is preferable that glass yarns account for >=1/4 of the texture (numver of yarns) of the wefts.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an explosion-proof pressure-sensitive adhesive tape for use in a treatment for preventing implosion of a cathode ray tube used in a television or the like.

[0002]

2. Description of the Related Art A cathode ray tube used in a television or the like may be implosed by a slight shock because the inside thereof is extremely vacuum. In order to prevent this implosion, the vicinity of the maximum outer diameter portion of the cathode ray tube is tightly fastened with a metal band to perform explosion-proof treatment. This metal band may damage the glass surface when directly bonded to the glass cathode ray tube, and when the band is tightened, the curved surface of the cathode ray tube causes the band to slip and the tightening and reinforcing effect may not be achieved. is there.

In order to avoid such a disadvantage caused by the direct contact between the metal band and the glass cathode ray tube, an explosion-proof adhesive tape is interposed between the metal band and the cathode ray tube. Adhesive tape prevents cracks from entering when a shock is applied to the cathode ray tube, and even if the cathode ray tube is destroyed by the shock, it holds glass fragments by adhesion with the tightening band,
It also plays the role of minimizing the scattering.

Conventionally, double-sided pressure-sensitive adhesive tapes, epoxy prepregs, etc. have been used as the explosion-proof pressure-sensitive adhesive tapes used for the above purpose.
It has become mainstream to use an adhesive tape using a glass cloth as a tape substrate as described in Japanese Patent No. 4291.

However, in the case of a cloth made of glass fiber alone, it is difficult to cut at the time of taping, breakage and strength decrease occur when the tape is rewound, and adhesion to a large-sized or flat type cathode ray tube is poor. However, there are drawbacks such as the use of a fiber surface treatment agent such as a silane coupling agent, which is expensive and requires a high technology in order to apply and hold the adhesive layer.

[0006]

DISCLOSURE OF THE INVENTION The present invention provides an explosion-proof tape for preventing implosion of a cathode ray tube, which is formed by sticking a tape around the mold match line near the maximum outer diameter portion of the cathode ray tube with an adhesive surface. An object of the present invention is to provide an explosion-proof adhesive tape for use in performing implosion-proof treatment by tightening a heated metal band on the surface of a heat-melting adhesive layer to complete the adhesion between the cathode ray tube and the band. Is.

Further, the present invention provides an inexpensive pressure-sensitive adhesive tape for interwoven cloth substrate explosion-proofing, which effectively utilizes the compressive breaking strength property of glass fiber as a material for the base material of the pressure-sensitive adhesive tape for explosion protection. The purpose is to do.

[0008]

In order to solve the above-mentioned problems, the present invention uses a yarn composed of natural or synthetic fibers as a warp component, and a glass yarn as a weft component alone or as a component similar to the warp component. The pressure-sensitive adhesive layer is provided on one side of the base material made of the interwoven fabric in which the yarn made of the natural or synthetic fiber is woven alternately or at intervals of several lines, and the heat-melting adhesive layer is provided on the opposite side. And the weft component is 0.5m high
5kgf / c for m mould match line step
The pressure-sensitive adhesive tape for explosion proof has a compression cutting resistance of m or more.

The explosion-proof pressure-sensitive adhesive tape of the present invention will be described with reference to the drawings. FIG. 1 is a sectional view of the explosion-proof pressure-sensitive adhesive tape of the present invention, and FIGS. 2 to 4 show the pressure-sensitive adhesive tape. FIG. 3 is a weaving diagram of warp threads and weft threads of a mixed woven fabric used as a base material.

As shown in FIG. 1, in the tape of the present invention, a heat-melting adhesive layer is formed on one surface of a base material made of a mixed woven fabric in which glass fibers are woven into weft threads, and a pressure-sensitive adhesive is formed on the other surface. Layers have been formed.

As shown in FIG. 2, in the interwoven fabric used as the base material, yarns made of natural or synthetic fibers such as cotton yarns, rayon yarns or polyester yarns are used as warp yarns, and all weft yarns are glass yarns. Used, or as shown in FIG. 3, the glass yarn and the same yarn as the warp yarn are alternately arranged, or, as shown in FIG. 4, the same yarn as the glass yarn and the warp yarn. Glass yarn is woven so that and are arranged every several yarns.

As the threads made of natural or synthetic fibers to be woven into the mixed woven cloth, those having a count of 10s to 40s, preferably 20s to 30s are used. Similarly, the glass thread is 25d to 500d, preferably 50d to 20.
Threads of 0d thickness are used. 2 for both warp and weft
It is preferable to weave at a density of 10 to 50 yarns per 5 mm, and it is preferable that at least ¼ or more of the weft yarn structure (number of yarns) is glass yarn.

The interwoven cloth formed by weaving the above warp and weft is usually 0.05 mm or more, preferably 0.1 mm.
The tape base material having the above thickness is used as the tape base material of the present invention. If the yarn diameter is too thin, it may cause insufficient strength during taping or insufficient compression cutting resistance, and if it is too thick, the gap between the cathode ray tube and the band may become large and slip may occur.

It is necessary that the above-mentioned woven cloth has a transverse compressive cutting strength that can withstand the pressure applied to the portion of the mold match line formed near the maximum outer diameter of the cathode ray tube in contact with the step. In particular, it is necessary to have a transverse compressive cutting resistance of 5 kgf / cm or more for a mold match line step having a height of 0.5 mm.

The tape based on the above-mentioned woven cloth is lapped by pressure so as to cover the mold match line around the cathode ray tube with the pressure-sensitive adhesive layer, and then the tape is heat-melt-bonded. A metal band heated to 60 ° C. or more on the agent layer, for example, a stainless steel plate or the like is circulated and tightened to complete the adhesion between the tape and the band, and thereby the cathode ray tube surface and the metal band through the tape. Plays a role of firmly bonding and.

The hot-melt adhesive layer formed on one surface of the base material of the tape of the present invention has excellent releasability from the pressure-sensitive adhesive layer formed on the opposite surface of the base material. Although it has excellent adhesiveness to the surface of the base material, when it comes into contact with a heated metal band, only the contact portion is melted by heat and the metal band can be firmly adhered to the base material. It is a thing.

As the heat-melting adhesive, one having a good film-forming ability, a melting point of 60 to 200 ° C., flexibility at room temperature, and high adhesiveness to a metal is used.
For example, resins such as polyethylene, ester resin, acrylic graft polyethylene, ethylene-vinyl acetate copolymer, styrene-butadiene copolymer, ethylene-acrylic copolymer, and polyamide are used alone or as a blend. When these resins do not have a sufficient releasing property for the pressure-sensitive adhesive layer on the opposite surface, an appropriate amount of releasing agent can be applied to the adhesive layer. Adhesive ^{layer, 10g / m 2 ~100g / m} 2, preferably is coated on the tape base material in an amount in the range of ^{30g / m 2 ~70g / m 2} .

The pressure-sensitive adhesive layer formed on the opposite surface of the tape of the present invention has good adhesiveness to the glass surface,
It is composed of an adhesive having high cohesiveness that resists shearing, and is usually formed of an acrylic or rubber adhesive as a material showing high adhesion to a substrate, but exhibits the above properties. Other than the above-mentioned pressure-sensitive adhesives can be used as long as they are used. These adhesives have a tape base material surface of 30 g / m ^{2 to} 3
00 g / m ² , preferably 50 g / m ^{2 to} 200 g / m
It is formed in the range of ² .

If the coating amount of the heat-melting adhesive and the pressure-sensitive adhesive is too large, the metal band becomes slippery, which is not preferable, and if it is too small, the adhesive force between the metal band and the cathode ray tube becomes insufficient. Become.

In order to produce the tacky adhesive tape used in the present invention, a hot-melt adhesive which has been previously melted at a temperature of 250 ° C. to 450 ° C. is formed into a film by an extruder and laminated on a substrate. In the case of resin that does not run on the machine, after applying or impregnating the substrate directly with a roll coater or dip coater, or after forming a film on the separator,
The heat-melting adhesive layer is formed by transferring to a substrate.

The pressure-sensitive adhesive layer on the opposite side is applied by a roll coater when it is a solvent type, and by using a calender when it is a solventless type, and particularly an extruder can be used as a solventless type adhesive. In this case, it can be applied by extrusion at the same time as the adhesive layer.

The adhesive tape produced as described above is supplied in a state of being slit into a necessary width so that it can be automatically wound. Needless to say, a separator is not required because the releasability between the heat melting adhesive layer and the pressure sensitive adhesive layer is excellent. Therefore, the taping machine for sticking to the cathode ray tube may have a simple structure, and at the same time, since it is a viscous adhesive tape having a strong base material strength, it has an advantage that a taping operation can be performed at high speed.

A metal tightening band expanded or forcibly stretched above the yield value of the material by induction heating, high frequency heating or flame heating is fitted into the taped cathode ray tube or is attached by tightening. To be done.

Therefore, the heated band is integrated with the CRT through the adhesive tape at the moment of contact with the adhesive tape wound around the CRT, and the band is further cooled. A high tightening force can be obtained by this, and as a result, an excellent reinforcing effect is exhibited.

Since the tape of the present invention is made of a mixed woven fabric as a base material, it not only has excellent adhesion to a flat tube or a large tube having a complicated curved surface, but also can be affected by heat and pressure during banding. Since the melted adhesive layer reaches the glass surface, the effect of fixing the permanent fluidity of the pressure-sensitive adhesive appears, the adhesive force between the cathode ray tube and the band is improved, and the fixing force of the pressure-sensitive adhesive layer is also improved. A high reinforcing effect can be obtained. Furthermore, the heat-melting type adhesive layer exposed on the surface, which is not in contact with this tightening band, retains a beautiful appearance without picking up dust and the like as it is.

The cathode ray tube reinforced by the tape of the present invention adheres to the surface of the cathode ray tube only by cutting only the tightening band and peeling it by 180 ° even if an abnormality is found in the finishing inspection step and it is necessary to recover. It has the advantage that it can be easily peeled off without leaving any glue residue on the layers, and the production loss rate is minimal.

[0027]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. Example 1 With a thickness of 0.25 mm, the weaving density is 16 yarns / 25 m in the longitudinal direction.
m (Suft yarn, yarn count RNS20s), 16 transverse directions / 2
Using a 5 mm (glass yarn, 75 d) interwoven cloth as a base material, polyethylene having a melting temperature of 90 ° C. as a heat-melting adhesive was laminated on one surface thereof as a layer having a coating amount of 37 g / m ² using an extruder, Then, an acrylic pressure sensitive adhesive roll coater was used to form a pressure sensitive pressure sensitive adhesive layer having a coating amount of 43 g / m ^{2 on} the opposite surface to manufacture an explosion proof adhesive tape having a total thickness of 0.27 mm.

A steel wire having a diameter of 0.5 mm was attached to the pressure-sensitive adhesive surface of the tape in parallel with the warp threads of the base material, and a pressure of 20 kgf / cm was applied for 10 seconds. The compression cutting resistance of the tape obtained by measuring the tensile strength of the tape was 12.5 kgf / cm.

The peeling force of the tape from the pressure-sensitive adhesive layer side against the glass plate and the peeling force of the heat-melting adhesive layer side from the stainless steel plate were applied at 300 ° C. for 5 seconds under a pressure of 10 kg / cm ^2. As a result of measuring the samples prepared by using a constant speed tension type tensile tester, respectively, 700 gf / cm, 85
It was 0 gf / cm. Further, the shear adhesive force to the glass plate on the pressure-sensitive adhesive layer side and the shear adhesive force to the stainless steel plate on the heat-melting adhesive layer side were measured on the measurement sample prepared under the same preparation conditions as the peel force measurement sample. Results, 15.6 each
It was kgf / m ² and 13.4 gf / cm ² .

The above tape was slitted into a width of 45 mm (length: 300 m) and wound up. The tape was wound around a mold match line step (maximum step 0.45 mm) near the outside of the cathode ray tube of a 29-inch color television for one round, and then the tape had an inner circumference length of 96% of the outer circumference of the cathode ray tube. A stainless steel tightening band was heated to about 450 ° C., fitted therein, rapidly cooled and tightened, and a required number of the tightened ones were manufactured, and a practical test described below was conducted.

Cut the band and tape of this test piece,
As a result of observing the thread breakage of the tape base material at the portions in contact with the respective positions of the long side portion, the corner portion and the short side portion of the cathode ray tube, there was no breakage of the base material in any of the portions.

The test specimen was kept at -45 ° C. for 5 hours and then +8.
As a result of measuring the displacement distance (mm) of the maximum displacement site after 10 cycles at 0 ° C. for 5 hours as one cycle, no displacement occurred.

Next, the forced displacement test of this test specimen was 70
In the atmosphere of ℃, the front side is fixed with the band part upward, a load of 120 kg is placed on the surface, and the distance (mm) of the maximum deviation part after holding for 30 minutes is measured.
Met.

When the front of this test piece was fixed upward and a 1-pound steel ball was dropped from a height of 5 feet, the number of cracks that passed directly under the band was 6.

When the test piece was dropped downward from a height of 1.5 m and broken, the glass retention rate (area measured with the naked eye) with respect to the entire circumference of the tightening band was 93%.

Examples 2 and 3 and Comparative Examples 1 and 2 Suft yarns are used as warp yarns, and the weft yarns are glass yarns alone (Example 3) or glass yarns and staple yarns are alternately woven (Example 2). A mixed woven fabric was produced, and a CRT explosion-proof pressure-sensitive adhesive tape was produced using the mixed woven fabric as a base material, and the adhesive property test and practical test were conducted in the same manner as described in Example 1. or,
As a comparative example, the same characteristic test and practical test were performed also on a cathode ray tube explosion-proof pressure-sensitive adhesive tape using a glass cloth whose warp and weft were made of glass (Comparative Example 1,
2). The results are shown in Tables 1 to 3.

[0037]

[Table 1]

[0038]

[Table 2]

[0039]

[Table 3]

From Tables 1 to 3, the pressure-sensitive adhesive tapes of Examples 2 and 3 of the present invention are the same as those found in the glass cloth alone base materials (Comparative Examples 1 and 2) in the peel test corresponding to rewinding. Not only the breakage of the material was not observed, but the explosion-proof property was also fully satisfied. In Comparative Examples 1 and 2 using the glass cloth base material, the tape lacks in flexibility, so that the base material may be cut off, which may interfere with taping to the cathode ray tube, or may be disadvantageous due to the tape base material being cut off due to the explosion-proof property after banding. There has occurred.

[0041]

As described above, according to the present invention, the pressure-sensitive adhesive tape for explosion is constructed by using as a base material a mixed woven fabric in which a number of glass yarns that give the mixed woven fabric sufficient transverse compressive cutting resistance as the weft yarn are woven. By doing so, it is possible to provide a viscous adhesive tape for explosion-proof cathode ray tube, which has the compression cutting resistance of glass yarn and the flexibility derived from natural or synthetic fiber yarn, has good adhesion to a cathode ray tube, and is inexpensive. It is a thing.

[Brief description of drawings]

FIG. 1 is a sectional view of an explosion-proof adhesive tape of the present invention.

FIG. 2 is a weaving diagram of a mixed woven fabric used as a base material for the tape of the present invention.

FIG. 3 is a weaving diagram of a mixed woven fabric used as a base material for the tape of the present invention.

FIG. 4 is a weaving diagram of the interwoven cloth used as the base material of the tape of the present invention.

Claims (1)

[Claims] 1. A natural or synthetic fiber yarn as a warp component,
Further, a pressure-sensitive adhesive layer is provided on one side of a base material made of a woven fabric in which glass yarn is singly used as a weft component, or natural or synthetic fiber yarns of the same type as the warp component are alternately or woven every few yarns, and the opposite surface is provided. Is provided with a heat-melting type adhesive layer, and it is 5k for a step of mold match line with a height of 0.5mm.
An explosion-proof pressure-sensitive adhesive tape having a transverse compressive cutting resistance of gf / cm or more.