JPH11297239A - Explosion-proof tape for cathode-ray tube and explosion-proof structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily and safely remove an explosion-proof tape attached to the outside periphery of a panel part of a cathode-ray tube and a shrink-fit metal band mounted on it, effectively reuse a cathode-ray tube which is mistakingly treated in dismantling recycling and explosion-proof treatment, and also implement easily the charge prevention of the cathode-ray tube as needed. SOLUTION: This explosion-proof tape is a tape 1 that has adhesive layers 12 on one surface of a supporting base material 11; and is wound around the outside periphery of a panel part of a cathode-ray tube through the adhesive layers and to mount a metal band 2 on it by means of shrinking fit; and wherein the supporting base material 11 is formed by including at least a propylene polymer layer of which content of a propylene ingredient is 40 wt.% and is formed wider than the metal band 2; and is an explosion-proof tape having the adhesive layers 12 only on the wider parts; and this explosion-proof structure is composed, without positioning the metal band 2 just above the adhesive layers 12 on the supporting base material 11 forming the wound layer of the explosion-proof tape, by mounting the metal band 2 on the wound layer by means of shrinking fit.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an explosion-proof tape and an explosion-proof structure for a CRT capable of easily removing an explosion-proof tape adhered to an outer periphery of a CRT and a metal band shrink-fitted thereon, thereby efficiently recycling the CRT.

[0002]

2. Description of the Related Art CRTs, which are diversified as television picture tubes, monitors for personal computers, word processors, and the like, are formed as vacuum glass tubes and are therefore subjected to explosion-proof treatment for the purpose of preventing implosion. I have. As the explosion-proof treatment, a structure is generally used in which an explosion-proof tape is wound around the outer periphery of a panel portion of a cathode ray tube, and a metal band is shrink-fitted thereon.

[0003] The explosion-proof tape is intended to prevent displacement of the metal band and to prevent damage to the cathode-ray tube due to the metal band. According to such an explosion-proof structure, the inside of the cathode-ray tube is large due to a vacuum. The bending moment due to the air pressure is relaxed and reduced by the bending moment in the opposite direction acting based on the tightening pressure of the metal band, thereby preventing implosion.

Heretofore, as the explosion-proof tape, there has been known a rubber-based tape which strongly adheres to a cathode ray tube on an entire surface of one side of an insulating support substrate obtained by laminating a layer made of polyester or polyethylene on a cloth made of glass or cotton. And those provided with an adhesive layer of acrylic or the like have been known. According to this, when the explosion-proof tape is adhered via the adhesive layer and the metal band is shrink-fitted thereon, the support base of the explosion-proof tape is melted and adheres firmly to the metal band.

[0005] However, from the viewpoints of preserving the global environment and effectively utilizing resources, it is necessary to collect the discarded cathode ray tubes,
If you try to recycle the glass material,
Since the metal band is firmly adhered to the cathode ray tube via the melt-solidified layer of the explosion-proof tape, especially the residue of the thermal decomposition of the adhesive layer generated during shrink fitting of the metal band, it is difficult to remove it. The protruding molten solidified explosion-proof tape is firmly adhered to the cathode ray tube, which requires mechanical processing such as shaving and polishing, and requires many hours and labor to complete the treatment. There was a problem that it was easily damaged, which had substantially stopped the recycling of cathode ray tubes.

In the above, if the explosion-proof tape is not sufficiently removed from the cathode ray tube, the explosion-proof tape component is carbonized when the cathode ray tube is disassembled into a panel portion and a funnel portion to form a cullet and melt to obtain a recycled glass. However, the quality of the glass material obtained by the reducing action is reduced. The lead glass forming the panel portion of the cathode ray tube is required to be particularly high in purity, and the incorporation of such impurities makes it difficult to regenerate the lead glass for forming the panel.

In addition, in the conventional explosion-proof structure, when an adhesion error such as misalignment of the metal band occurs, even if the metal band is cut and removed, the molten and solidified material of the explosion-proof tape remains in the cathode ray tube. And the cathode ray tube is easily scratched. Such a cathode ray tube can be salvaged and reused by removing the explosion-proof tape residue, but if it is damaged during the removal of the explosion-proof tape residue, it may be exploded due to stress concentration and cannot be put to practical use.

On the other hand, the surface of a cathode ray tube tends to be positively charged due to electrostatic induction. Therefore, discharge measures are usually taken for the cathode ray tube. Conventionally, as a countermeasure against the discharge, a method has been adopted in which metal particles are applied to the panel portion of a cathode ray tube to form an electrode, the electrode and an explosion-proof tape are connected with a metal tape, and the metal tape is connected to a ground electrode. I was However, there has been a problem that the work of applying metal particles and the work of connecting metal tape require a lot of time and labor.

[0009]

SUMMARY OF THE INVENTION The present invention provides an explosion-proof treatment which can easily and safely remove an explosion-proof tape applied to the outer periphery of a panel portion of a cathode ray tube and a metal band shrink-fitted thereon.
An object of the present invention is to develop an explosion-proof tape and an explosion-proof structure of a CRT that can efficiently disassemble and recycle a CRT or reuse a CRT that has undergone an explosion-proof treatment, and can easily achieve antistatic charging of the CRT if necessary.

[0010]

According to the present invention, there is provided a tape having a pressure-sensitive adhesive layer on one side of a supporting substrate, wound around the panel portion of the cathode ray tube through the pressure-sensitive adhesive layer, and shrink-fitting a metal band thereon. And the supporting base material has a propylene component content of 4
An explosion-proof tape, comprising at least a propylene-based polymer layer of 0% by weight or more, formed wider than the metal band, and having an adhesive layer only in the wide portion, and an explosion-proof tape thereof Is wound around the outer periphery of the panel portion of the cathode ray tube, and the metal band is shrink-fitted onto the winding layer in a state where the metal band is not positioned above the adhesive layer in the supporting base material forming the winding layer. An object of the present invention is to provide a CRT explosion-proof structure.

[0011]

According to the present invention, even if the supporting base material is melted and adhered to the metal band or the cathode ray tube at the time of shrink fitting of the metal band, the adhesive force is such that the displacement of the metal band due to the shearing force can be prevented. The metal band can be easily removed from the explosion-proof tape, and the supporting substrate can be easily removed from the cathode ray tube. This is due to the fact that the supporting base material having the above-described structure has a low melt adhesion to a metal band or a CRT. On the other hand, the configuration as a wide supporting substrate in which the shrink-fitting metal band is not positioned on the adhesive layer can prevent the adhesive layer from being thermally decomposed at the time of shrink-fitting of the metal band, thereby preventing the residue from being thermally decomposed. In addition, the initial characteristics of the pressure-sensitive adhesive layer can be favorably maintained.

Therefore, the metal band can be cut, and can be easily and efficiently removed even by manual work by heating and expanding in accordance with shrink fitting, and the explosion-proof tape remaining on the cathode ray tube is also adhered through the supporting base material. It can be easily and efficiently peeled off even by manual operation integrally with the layer. as a result,
Glass that has a metal tube and explosion-proof tape applied to the CRT as an explosion-proof treatment is easily removed via manual work, dismantles the CRT into a panel part and a funnel part, and melts it to maintain a high purity before treatment. The material can be recycled, and it can be used efficiently for recycling as a glass material of the same quality as before regeneration.

[0013] Further, even in the event of a manufacturing error such as a bonding error such as a displacement of a metal belt during the explosion-proof treatment, the metal band and the explosion-proof tape are removed more easily and without damage than the CRT, and the CRT is salvaged. It can be efficiently reused without dismantling the CRT.

On the other hand, in the case where a conductive material is used as a supporting base material in the thickness direction via conductive fibers, the cathode ray tube can be discharged. That is, the charging of the cathode ray tube first energizes the conductive fibers of the supporting substrate, and then energizes the metal band on the conductive fibers. Therefore, it is possible to discharge by connecting the metal band in the CRT of the explosion-proof structure to the ground electrode provided on the outer wall panel, and the explosion-proof structure can also serve as a discharge mechanism and form an explosion-proof and discharge structure with a small number of parts. .

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The explosion-proof tape of the present invention has an adhesive layer on one side of a supporting base material, is wound around the outer periphery of a CRT panel portion via the adhesive layer, and a metal band is shrink-fitted thereon. Wherein the supporting base material has at least a propylene-based polymer layer having a propylene component content of 40% by weight or more, and is formed wider than the metal band, and only in the wide portion thereof. It has a pressure-sensitive adhesive layer and, if necessary, conductive fibers, and conducts electricity in the thickness direction.

FIG. 1 shows an example of an explosion-proof tape according to the present invention.
(A), (b) and FIGS. 2 (a), (b). FIG. 3 shows an example of an explosion-proof structure according to the present invention. FIG. 1
(A), FIG. 2 (a) is a front sectional view, FIG. 1 (b), FIG.
(B) is a plan view. 1 is an explosion-proof tape, 11 is a supporting base material, 12 is an adhesive layer, and 13 is a conductive fiber provided as needed. Reference numeral 2 denotes a metal band, and reference numeral 3 denotes a cathode ray tube including a panel portion 31 and a funnel portion 32. In FIG. 1, the metal band 2 shrink-fitted on the explosion-proof tape 1 is shown by a virtual line.

In the present invention, the explosion-proof tape is a support base material having at least a propylene-based polymer layer having a propylene component content of 40% by weight or more, having an adhesive layer on one side, and a metal to be shrink-fitted thereon. A band formed wider than the band and having an adhesive layer only in the wide portion is used.

The propylene-based polymer forming the above-mentioned supporting base material is, for example, a homopolymer of propylene or a random or block type of propylene and ethylene prepared so that the content of the propylene component is 40% by weight or more. Copolymers and ethylene-propylene rubber,
Examples thereof include a mixture of polypropylene and polyethylene, and a mixture of two or more of these polymers.

A support base material having a layer made of propylene homopolymer on at least the surface thereof is preferable from the viewpoint of easy peeling from the shrink-fitted metal belt. On the other hand, when the shrink-fitting position of the metal band in the cathode ray tube is tapered or the like and the band can slip and cause a position shift, when a position fixing measure such as a shift prevention measure is desired,
A support base material that generates some adhesive strength with the metal band at the time of shrink fitting can also be used.

In order to achieve the above-mentioned adhesive strength,
It contains components such as ethylene and isoprene which show good adhesion to metal bands, such as the above-mentioned copolymers containing ethylene components or polyethylene mixtures, or copolymers or mixtures thereof containing isoprene or butadiene etc. A support substrate having at least a surface made of a layer made of a propylene-based polymer can be preferably used.

In the above, a propylene-based polymer which is preferable in terms of compatibility of the metal band with ease of peeling and adhesion to prevent slippage, has a propylene component content of 50% by weight.
As mentioned above, it is especially 55 to 95% by weight, especially 65 to 85% by weight. The content of the propylene component is 40% by weight.
If the propylene-based polymer is less than the above, the adhesive force with the shrink-fitted metal band becomes excessive, and it is difficult to achieve simple peeling of the metal band by manual operation or the like.

On the other hand, the above-mentioned prevention of slippage of the metal band is as follows.
It is also possible to cope with the uneven effect of the coarse cloth made of glass, cotton, or the like. In that case, a support base material or the like obtained by laminating a film made of the propylene-based polymer on the cloth is used. In this case, a propylene homopolymer may be used.

The thickness of the supporting substrate can be appropriately determined according to the size of the cathode ray tube and the like, and can be set to a thickness exceeding 1 mm, but is generally 5 to 500 μm, preferably 10 to 3 μm.
00 μm, especially 20-200 μm. Appropriate surface treatment such as corona treatment, plasma treatment, sputter etching treatment, flame treatment, primer treatment with a primer, etc. is performed on the surface of the support substrate with the adhesive layer to improve the adhesion to the adhesive layer. be able to.

As shown in the figure, the adhesive layer 12 has only one end in the width direction on one side of the support base material 11 along the length direction.
It is provided with a width that does not overlap with the metal band 2 mounted thereon. Thereby, when the metal band is shrink-fitted, the temperature is transmitted to the adhesive layer via the support base material, and the adhesive layer is prevented from being thermally decomposed to become a thermal decomposition residue.

For the formation of the above-mentioned pressure-sensitive adhesive layer, for example, a suitable pressure-sensitive adhesive such as a rubber-based or acrylic-based pressure-sensitive adhesive can be used. Preferred adhesive layers are those that can be peeled off integrally with the supporting substrate without leaving any adhesive on the cathode ray tube, or those that can be easily decomposed by heating even if adhesive remains, and can be easily removed by heat treatment.

Such an adhesive layer is of a type that hardly causes adhesive residue, such as a polyisobutylene-based adhesive or an acrylic-based adhesive having a copolymer of an alkyl acrylate and acrylic acid as a base polymer such as lauryl methacrylate; Further, it can be formed of an appropriate known pressure-sensitive adhesive of a type which is easily decomposed by heating even if the adhesive remains.

The adhesive layer may be attached to the supporting substrate by, for example, mixing the components such as a base polymer via a solvent such as toluene or ethyl acetate as necessary, and then adhering the adhesive liquid comprising the mixture to the supporting substrate. It is performed by an appropriate method such as a method of applying and drying on a predetermined part by an appropriate method such as a doctor blade method or a method of transferring a band-shaped adhesive layer provided on a separator to a supporting substrate according to the method. be able to. The thickness of the adhesive layer may be appropriately determined, but is generally 1 to 500 μm.
m, especially 3 to 200 μm, especially 5 to 100 μm.

In the explosion-proof tape according to the present invention, as shown in FIG. 2, the conductive fiber 13 can be provided on the supporting base material 11 in a state where the conductive fiber 13 can be energized in the thickness direction. According to this, the electric charge of the cathode ray tube can be discharged through the conductive band through the conductive fiber to the metal band shrink-fitted thereon, thereby forming an explosion-proof structure that also serves as a discharge. The discharge is achieved by connecting an explosion-proof metal band provided on the cathode ray tube to a ground electrode provided on the outer wall panel.

The conductive fiber is provided on the supporting base material by, for example, a method in which conductive fiber is sewn on the supporting base material. An appropriate system that can be energized may be used. The conductive fibers also have a diameter of 0.01 to 2 mm, preferably 0.1 to 1 mm.
mm, in particular, metal fibers such as copper wires of 0.2 to 0.8 mm, carbon fibers, plastic fibers mixed with conductive powders such as metal powders and carbon powders, and conductive films such as metal films deposited or plated on plastic fibers. An appropriate material such as one adhered by a method or the like can be used.

The explosion-proof structure of the CRT according to the present invention is such that the explosion-proof tape 1 is wound around the outer periphery of the panel portion 31 of the CRT 3 as shown in FIG. The metal band is shrink-fitted onto the winding layer without the metal band 2 being positioned above.

The explosion-proof structure is formed, for example, by winding an explosion-proof tape around the panel portion of the cathode ray tube via the adhesive layer, and forming a metal band made of steel or the like narrower than the explosion-proof tape through the wound layer. Can be performed according to the conventional method except for the above-mentioned point, such as a method of shrink-fitting the center part of the explosion-proof tape.

The gap between the end of the adhesive layer and the end of the metal band in the explosion-proof tape can be appropriately determined based on the shrink-fitting temperature of the metal band and the like.
It is preferably from 0.5 to 10 mm, more preferably from 1 to 8 mm, particularly preferably from 2 to 6 mm, from the viewpoint of preventing the adhesive layer from being thermally decomposed at such a temperature and preventing the explosion-proof tape from being unnecessarily widened at such a temperature.

In the present invention, an explosion-proof tape which can be easily peeled off from a metal band is used. However, the force required for the explosion-proof treatment of a cathode-ray tube is, as described above, the bending moment acting on the cathode-ray tube having a vacuum inside via the atmospheric pressure. Since this is a tightening force via a metal band (FIG. 3, F) that can alleviate and reduce the force, the tightening force can be sufficiently generated only by the metal band. Therefore, even if the adhesive strength between the metal band and the explosion-proof tape is weak, the tightening force of the metal band can be sufficiently exerted. As a result, the present invention can exhibit the same explosion-proof effect as the conventional one.

[0034]

EXAMPLES Example 1 100 parts of propylene homopolymer (parts by weight, the same applies hereinafter)
50 μm thick and 5 width consisting of a mixture of
A weight average molecular weight of about 1 was added to both ends of one side of a 5 mm film.
An explosion-proof tape was obtained by providing a 20-μm-thick adhesive layer having a width of 5 mm and comprising 100,000 polyisobutylene. Next, an explosion-proof tape having a width of 55 mm is wound around and adhered to the outer periphery of the panel portion of the cathode ray tube via the adhesive layer.
Was heated at 500 ° C. so as not to be located on the adhesive layer of the explosion-proof tape and shrink-fitted to form an explosion-proof structure.

Example 2 An extruded film composed of a mixture of 30 parts of a propylene homopolymer, 40 parts of an ethylene / propylene random copolymer having an ethylene content of 30% by weight, and 30 parts of an ethylene homopolymer was stretched as a supporting substrate. Thickness 5
An explosion-proof tape was obtained according to Example 1 except that a 0 μm film was used, and an explosion-proof structure was formed using the tape. The acrylic pressure-sensitive adhesive is obtained by blending 60 parts of dibutyl phthalate and 4 parts of a melamine cross-linking agent with 100 parts of a base polymer obtained by copolymerizing 95 parts of butyl acrylate and 5 parts of acrylic acid.

Example 3 A copper wire having a diameter of 0.5 mm was sewn as a continuous line in the length direction of the support base material at the center in the width direction of the support base material, and was used as a support base material. An explosion-proof tape was obtained according to Example 1 and used to form an explosion-proof structure.

Comparative Example 1 In accordance with Example 1, 100 parts of masticated rubber and 80 parts of a natural rosin-based resin were applied to one surface of a 50 μm thick film made of a mixture of 100 parts of low-tensile polyethylene and 0.5 part of a slipping agent. Then, a rubber-based adhesive layer having a thickness of 20 μm comprising a mixture of 10 parts of phenol resin and 5 parts of zinc resin was provided to obtain an explosion-proof tape, which was used to form an explosion-proof structure.

Comparative Example 2 In accordance with Example 1, one side of a 50 μm thick stretched film made of a mixture of 60 parts of an ethylene homopolymer and 40 parts of an ethylene / propylene block copolymer having an ethylene content of 30% by weight was coated with acrylic acid. 95 parts of butyl and acrylic acid 5
Explosion-proof tape was obtained by providing an adhesive layer having a thickness of 20 μm made of an acrylic adhesive in which 20 parts of a terpene phenolic resin and 3 parts of an isocyanate crosslinking agent were blended with 100 parts of a base polymer obtained by copolymerizing the above parts. To form an explosion-proof structure.

Comparative Example 3 Example 1 was repeated except that an adhesive layer was provided on one entire surface of the supporting substrate.
An explosion-proof tape was obtained according to the above, and an explosion-proof structure was formed using the tape.

Evaluation Test 1 After removing the steel band from the cathode ray tubes obtained in Examples and Comparative Examples by expanding the steel band by conduction heating and removing the explosion proof tape component remaining on the cathode ray tube and the explosion proof tape component transferred to the steel band. The removability by hand was examined.

The above results were as follows. Example 1: Most of the explosion-proof tape was peeled off from the CRT together with the steel band, and the removal of the explosion-proof tape from the steel band through the finger and the removal of the explosion-proof tape remaining on the CRT were easy. Examples 2 and 3: Approximately half of the explosion-proof tape peeled off from the CRT together with the steel band, and it was easy to peel off the explosion-proof tape from the steel band via a finger and peel off the explosion-proof tape remaining on the CRT. there were. Comparative Examples 1 and 2: The support base material and the adhesive layer of the explosion-proof tape were firmly adhered to both the steel band and the CRT, and could not be removed by a finger. Comparative Example 3: The supporting substrate of the explosion-proof tape was firmly adhered to both the steel band and the CRT, and could not be removed by a finger.

Evaluation Test 2 An earth was placed on the metal belt having the explosion-proof structure obtained in Example 3, and the cathode ray tube was operated for one week to check the charged state.

[Brief description of the drawings]

FIG. 1 is an explanatory view of an example of an explosion-proof tape.

FIG. 2 is an explanatory view of another example of an explosion-proof tape.

FIG. 3 is an explanatory partial sectional view of an example of an explosion-proof structure.

[Explanation of symbols]

1: Explosion-proof tape (11: support base material 12: adhesive layer 1)
3: Conductive fiber 2: Metal band 3: CRT (31: Panel part)
32: funnel section)

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazunari Shibata 1-2-1, Shimohozumi, Ibaraki-shi, Osaka Nitto Denko Corporation (72) Inventor Mitsugu Hasegawa 1-1-1, Shimohozumi, Ibaraki-shi, Osaka No. 2 Inside Nitto Denko Corporation (72) Inventor Wasu, 6-7-35 Kita Shinagawa, Shinagawa-ku, Tokyo Inside Sony Corporation (72) Inventor Toshio Nagata 6-35, Kita-Shinagawa, Shinagawa-ku, Tokyo No. Sony Corporation

Claims (4)

[Claims] 1. A tape for providing a pressure-sensitive adhesive layer on one side of a support base material, winding the support layer on the outer periphery of a panel portion of a cathode ray tube, and shrink-fitting a metal band thereon. The material has at least a propylene-based polymer layer having a propylene component content of 40% by weight or more, and is formed wider than the metal band, and has an adhesive layer only in the wide portion. Explosion proof tape. 2. The explosion-proof tape according to claim 1, wherein the adhesive layer is made of polyisobutylene. 3. The explosion-proof tape according to claim 1, wherein the supporting substrate is energized in the thickness direction via conductive fibers. 4. The explosion-proof tape according to claim 1, which is wound around an outer periphery of a panel portion of a cathode ray tube, and in a state where a metal band is not positioned above an adhesive layer in a support base material forming the wound layer. An explosion-proof structure for a cathode ray tube, wherein the metal band is shrink-fitted on the winding layer.