JPH05339544A - Surface protective film or sheet for cathode ray tube, and method for protecting surface of cathode ray tube - Google Patents

Abstract

PURPOSE:To obtain the title thermoplastic resin film or sheet which, when temporarily bonded to the pretreated front surface of a cathode ray tube, neither leaves adhesive cement behind nor causes clouding on the surface and which is useful for preventing damage to an attachment in the assembly step by forming a self-adhesive layer on one side of the film or sheet under specified conditions. CONSTITUTION:A self-adhesive layer 11 is formed by applying a self-adhesive (e.g. an acrylic self-adhesive) to one side of a thermoplastic resin film or sheet 1pref. having a 1% modulus of 0.05-0.5kg/cm (e.g. a low-density PE film) along at least one edge of the side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface protecting film or sheet for a cathode ray tube and a method for protecting a cathode ray tube in the process of incorporating an accessory.

[0002]

2. Description of the Related Art Conventionally, in the manufacture of cathode ray tubes, the main body of the cathode ray tube is first made of glass, and accessory parts such as an electron gun are incorporated into the cathode ray tube. A surface protective film having a pressure-sensitive adhesive layer provided on the entire one surface of the plastic resin film was temporarily attached to the front surface of the cathode ray tube. Recently, for the purpose of preventing the reflection of the surrounding scene on the front surface of the cathode ray tube and improving the color development,
BACKGROUND ART A coating film is formed with a chemical agent, or surface treatment is performed by roughening with a strong acid.

[0003]

However, a surface protection film having a pressure-sensitive adhesive layer on one side of a conventional thermoplastic resin film is temporarily attached to such a cathode ray tube whose surface has been surface-treated. And, the adhesive causes a chemical reaction by contacting the chemical agent forming the coating film, or enters the concave portion of the rough surface, even after peeling the surface protective film,
There has been a problem that the adhesive component remains, causing contamination such as adhesive residue and cloudiness.

The present invention solves the above-mentioned problems of the prior art, and even in a CRT having a surface treated on the front surface, no adhesive residue or fogging occurs after peeling, and no damage occurs in the process of assembling accessory parts. It is an object of the present invention to provide a surface protection film or sheet for a cathode ray tube and a method for protecting a cathode ray tube that can prevent the above.

[0005]

According to a first aspect of the present invention, a pressure-sensitive adhesive layer is formed along at least one end of one surface of a thermoplastic resin film or sheet. According to the invention, a width of 10 mm or more is attached so that a part of the pressure-sensitive adhesive layer of the pressure-sensitive adhesive tape is exposed to the outside in a width of 5 to 100 mm along both ends of the thermoplastic resin film or sheet. According to the invention of Item 3, a pressure-sensitive adhesive layer is formed on one entire surface of a thermoplastic resin film or sheet, and another thermoplastic resin film or sheet is laminated leaving both ends of the pressure-sensitive adhesive layer. ,
According to the invention of claim 4, the 1% modulus of the thermoplastic resin film or sheet is 0.05 to 0.5 kg / cm,
According to the invention of claim 5, the surface protection film or sheet for a cathode ray tube according to any one of claims 1 to 4 is temporarily attached to the front surface of the cathode ray tube so that the adhesive layer does not come into contact with the front surface of the cathode ray tube. It is what

The raw material of the thermoplastic resin film or sheet used in the invention of claims 1 to 4 is:
Since the plasticizer contained in the soft polyvinyl chloride may exude to the surface and contaminate the surface of the Braun tube, a polyolefin resin such as polyethylene or polypropylene, or polyethylene terephthalate is preferably used.

The thickness of the thermoplastic resin film or sheet is not particularly limited, but is preferably 20 to 200 μm,
More preferably, it is 40 to 100 μm. If it is less than 20 μm, the strength is insufficient and the effect of preventing damage is small. 200 μm
If it exceeds, the waist is too strong and it is difficult to follow the curvature of the front surface of the cathode ray tube.

In the inventions of claims 1 and 3, the pressure-sensitive adhesive for forming the pressure-sensitive adhesive layer on one surface of the thermoplastic resin film or sheet is not particularly limited, and a rubber-based pressure-sensitive adhesive or an acrylic pressure-sensitive adhesive is preferable. used. To form the pressure-sensitive adhesive layer, the raw material resin may be dissolved in a solvent for coating or may be melted by heating and laminated. The thickness of the pressure-sensitive adhesive layer is generally 5 to 40 μm.

In order to improve the affinity between the thermoplastic resin film or sheet used in the first and third aspects of the invention and the adhesive layer, the surface of the thermoplastic resin film or sheet is subjected to corona discharge treatment. May be.

The thermoplastic resin film or sheet used in the invention of claim 4 has a 1% modulus of 0.05 to 0.5 kg / cm. If it is less than 0.05 kg / cm,
When the surface protection film or sheet is too weak and the surface protection film or sheet is temporarily attached to the surface of the cathode ray tube, the elongation of the film or sheet is large, and after the temporary attachment, the film or sheet tends to shrink and spontaneously peel off. If it exceeds 0.5 kg / cm, the waist is too strong and it is difficult to follow the curve of the front surface of the cathode ray tube, and wrinkles are formed.

As a raw material for the support of the pressure-sensitive adhesive tape used in the second aspect of the present invention, a polyolefin resin such as polyethylene or polypropylene, or polyethylene terephthalate is preferably used. The thickness of the support is not particularly limited, but is preferably 20 to 200 μm, more preferably 40 to 100 μm. If it is less than 20 μm, it is too stiff and it is difficult to attach it to the thermoplastic resin film, and if it exceeds 100 μm, the circumference of the adhesive tape adhesive part and the non-adhesive part are too different when it is formed into a roll. For this reason, the non-sticking portion of the thermoplastic resin film or sheet has folds and wrinkles, resulting in a poor external appearance and poor workability during temporary attachment to the cathode ray tube.

The pressure-sensitive adhesive forming the pressure-sensitive adhesive layer of the pressure-sensitive adhesive tape used in the invention of claim 2 is not particularly limited, and a rubber-based pressure-sensitive adhesive or an acrylic pressure-sensitive adhesive usually used as a pressure-sensitive adhesive of a pressure-sensitive adhesive tape is used. Agents are preferably used. To form the pressure-sensitive adhesive layer, the raw material resin may be dissolved in a solvent for coating or may be melted by heating and laminated. The thickness of the pressure-sensitive adhesive layer is generally 5 to 20 μm. In order to improve the affinity between the support of the adhesive tape and the adhesive layer, the support surface may be subjected to corona discharge treatment.

The width of the portion of the adhesive tape that is adhered to the thermoplastic resin film or sheet is 10 mm or more. 10 mm
If it is less than this range, the adhesive strength between the adhesive tape and the thermoplastic resin film or sheet will be insufficient, and the adhesive tape will peel off from the thermoplastic resin film or sheet with time after temporary attachment to the cathode ray tube. The upper limit is not specified, but exceeding 50 mm is not practical in terms of cost.

The width of the portion of the pressure-sensitive adhesive layer of the pressure-sensitive adhesive tape exposed to the outside of the thermoplastic resin film or sheet is 5 to 100 mm. If it is less than 5 mm, the adhesive strength with the cathode ray tube becomes insufficient, so after the temporary attachment to the cathode ray tube, the adhesive tape peels off from the cathode ray tube over time,
If it exceeds 100 mm, the adhesive strength with the CRT is too strong, and the workability when peeling off the surface protective film or sheet before incorporating the CRT into the frame of the TV deteriorates.

As a raw material of the thermoplastic resin film or sheet laminated on the pressure-sensitive adhesive layer in the invention of claim 3, soft polyvinyl chloride contains plasticizer oozes on the surface to contaminate the surface of the cathode ray tube. Therefore, polyolefin resins such as polyethylene and polypropylene and polyethylene terephthalate are preferably used. The thickness of the laminated thermoplastic resin film or sheet is
Although not particularly limited, it is preferably 20 to 100 μm, more preferably 40 to 80 μm. If it is less than 20 μm, the strength is insufficient and the effect of preventing damage is small. When it exceeds 100 μm, the waist is too strong and it is difficult to follow the curvature of the front surface of the cathode ray tube. The size of the laminated thermoplastic resin film or sheet is not particularly limited, but it is necessary to have a size large enough to cover the front surface of the cathode ray tube.

The width of the pressure-sensitive adhesive layer left on both ends of the laminated thermoplastic resin film or sheet is 5 to 100.
mm. If it is less than 5 mm, the adhesive strength with the cathode ray tube becomes insufficient, so the adhesive tape will peel off from the cathode ray tube with time after temporary attachment to the cathode ray tube, and if it exceeds 100 mm, the adhesive strength with the cathode ray tube will be too strong. This is because the workability when peeling off the surface protection film or sheet before assembling into the TV frame becomes poor.

[0017]

According to the invention of claims 1 to 4, since the adhesive layer is formed so as to be exposed only at both ends of the surface protective film or sheet, the adhesive layer is temporarily attached so as not to contact the front surface of the cathode ray tube. You can do it.

According to a fifth aspect of the present invention, the surface protective film or sheet in which the adhesive layer is exposed only at both ends is temporarily attached to the front surface of the cathode ray tube so that the adhesive layer does not come into contact with the surface. Therefore, when the surface protection film or sheet after use is peeled from the cathode ray tube, no adhesive residue or clouding occurs.

[0019]

EXAMPLES Examples of the present invention will be specifically described below.
The invention is not limited to the examples. Example 1 As shown in FIG. 1, low-density polyethylene having a 1% modulus of 0.08 kg / cm (“Mirason manufactured by Mitsui Petrochemical Industry Co., Ltd.”
12 ") having a thickness of 100 μm and a width of 400 mm, one side of the thermoplastic resin film 1 is coated with an acrylic adhesive along both ends in the width direction to form an adhesive layer 11 having a thickness of 10 μm and a width of 25 mm. A surface protection film was obtained.

Example 2 As in Example 1, except that a thermoplastic resin film made of polypropylene having a 1% modulus of 0.46 kg / cm (“Mitsui Noblene FL-100” manufactured by Mitsui Toatsu Chemicals, Inc.) was used. Then, a surface protection film was obtained.

Example 3 As shown in FIG. 4, a low-density polyethylene (“Mirason 12” manufactured by Mitsui Petrochemical Co., Ltd.) having a thickness of 100 μm and a width of 4
A rubber-based pressure-sensitive adhesive is applied to one surface of a support 21 having a thickness of 40 μm and made of polypropylene along both ends in the width direction of the thermoplastic resin film 1 having a thickness of 00 mm.
Adhesive tape 2 with a width of 50 mm (“Taflight Tape # 835-B” manufactured by Sekisui Chemical Co., Ltd.) with a width of 25 mm for the adhesive layer 22
The surface protection film was obtained by sticking so that the minutes were exposed to the outside.

Example 4 Polypropylene (“Mitsui Noblen FL manufactured by Mitsui Toatsu Chemicals, Inc.
A surface protective film was obtained in the same manner as in Example 3, except that a thermoplastic resin film composed of -100 ") was used.

Example 5 The procedure of Example 3 was repeated except that the pressure-sensitive adhesive tape was attached so that a width of 40 mm of the pressure-sensitive adhesive layer was exposed to the outside.
A surface protection film was obtained.

Example 6 As in Example 3, except that the pressure-sensitive adhesive tape was attached so that the width of the pressure-sensitive adhesive layer was exposed to the outside of 5 mm.
A surface protection film was obtained.

Example 7 As shown in FIG. 6, a low density polyethylene (“Mirason 12” manufactured by Mitsui Petrochemical Industries, Ltd.) having a thickness of 50 μm and a width of 420
mm thermoplastic resin film 1 is subjected to corona discharge treatment (voltage 240V, current value 6A) on one side, and then 100 parts by weight of NR pale crepe and 75 parts by weight of polyterpene resin (mp = 100 ° C) on the entire corona discharge treated surface. Part, and an anti-aging agent (“Irganox 1010” manufactured by Ciba-Geigy) 2 parts by weight are applied to form an adhesive layer 11 having a thickness of 10 μm.
Low-density polyethylene (Mitsui Petrochemical Co., Ltd. “Mirason
A thermoplastic resin film 3 having a thickness of 50 μm and a width of 400 mm composed of 12 ″) was laminated on the pressure-sensitive adhesive layer 11 leaving both ends at a width of 10 mm to obtain a surface protective film.

Example 8 Polypropylene (“Mitsui Noblen FL, manufactured by Mitsui Toatsu Chemicals, Inc.
A surface protective film was obtained in the same manner as in Example 7, except that a thermoplastic resin film composed of -100 ") was used.

Example 9 The width of the thermoplastic resin film 1 forming the adhesive layer is 600
mm, and a surface protective film was obtained in the same manner as in Example 7 except that the both ends were laminated to leave a width of 100 mm.

Example 10 Low-density polyethylene (“Mirason manufactured by Mitsui Petrochemical Industry Co., Ltd.
12 ”) and an ethylene-vinyl acetate copolymer (“ Eva Flex 260 ”manufactured by Mitsui DuPont Polychemical Co., Ltd.) by a T-die so that the former has a thickness of 100 μm, the latter has a thickness of 20 μm and a width of 400 mm. Extruded by extrusion method, low density polyethylene (Mirase 1
A thermoplastic resin film 3 having a thickness of 50 μm and a width of 400 mm composed of 2 ″) was laminated on the pressure-sensitive adhesive layer 11 leaving both ends at a width of 10 mm to obtain a surface protective film.

Comparative Example 1 The same thermoplastic resin film as in Example 1 was subjected to corona discharge treatment (voltage 240 V, current value 6 A) on one side, and then an acrylic adhesive was applied to the entire surface of the corona discharge treated to a thickness of 10 μm. Was applied to form a pressure-sensitive adhesive layer to obtain a surface protective film.

Comparative Example 2 Low Density Polyethylene (“Mirason manufactured by Mitsui Petrochemical Industry Co., Ltd.
12 ”) and an ethylene-vinyl acetate copolymer (“ Eva Flex 260 ”manufactured by Mitsui DuPont Polychemical Co., Ltd.) by a co-extrusion method using a T-die so that the former thickness is 100 μm and the latter thickness is 20 μm. By extrusion molding, a surface protective film was obtained.

Comparative Example 3 The same adhesive tape as in Example 3 was adhered so that the adhesive layer 43 mm in width was exposed to the outside (adhesion width of the adhesive tape 2 to the thermoplastic resin film 1). Was 7 mm), and a surface protective film was obtained in the same manner as in Example 3.

Comparative Example 4 The procedure of Example 3 was repeated except that the pressure-sensitive adhesive tape was attached so that the width of the pressure-sensitive adhesive layer was 4 mm exposed to the outside.
A surface protection film was obtained.

Comparative Example 5 Example 3 was repeated except that a thermoplastic resin film made of ultra low density polyethylene (“Excellen VL200” manufactured by Sumitomo Chemical Co., Ltd.) having a 1% modulus of 0.04 kg / cm was used.
A surface protective film was obtained as described above.

Comparative Example 6 As in Example 3, except that a thermoplastic resin film made of polypropylene having a 1% modulus of 0.52 kg / cm (“HIPOL F600” manufactured by Mitsui Petrochemical Industry Co., Ltd.) was used. A surface protection film was obtained.

As shown in FIGS. 2, 3 and 5, the surface protective films obtained in Examples 1 to 10 and Comparative Examples 1 to 6 were subjected to surface treatment on the pressure-sensitive adhesive layer except for Comparative Examples 1 and 2. The cathode ray tube was temporarily adhered so as not to come into contact with the front surface of the cathode ray tube, and the presence or absence of wrinkles at the time of temporary adhesion and the presence or absence of peeling of the surface protective film after leaving for 60 minutes at 23 ° C. after temporary adhesion were tested. Then, as a result of the above test, Example 1 in which neither wrinkles nor peeling occurred
10 to 10 and the surface protection films obtained in Comparative Examples 1 and 2 were left for 60 minutes at room temperature after temporary attachment and then left in a heating furnace at 40 ° C. for 7 days and 14 days, and then on the surface of the cathode ray tube when peeled off. The presence or absence of glue residue or cloudiness was tested.

Table 1 shows the 1% modulus values and the test results of the thermoplastic resin films of Examples 1 to 10 and Comparative Examples 1 to 6 described above.

[Table 1] As described above, in Examples 1 to 10, there was no peeling during temporary attachment, and neither adhesive residue nor fogging occurred after peeling.
On the other hand, Comparative Example 1 already had an adhesive residue after standing for 60 minutes at room temperature, and Comparative Example 2 was cloudy. Comparative Examples 3 to 5 were peeled off over time, and Comparative Example 6 was wrinkled.

[0037]

The surface protection film or sheet for a cathode ray tube and the method for protecting a cathode ray tube according to the present invention are constructed as described above, and therefore, even in a cathode ray tube whose surface is subjected to a surface treatment, an adhesive residue or fogging occurs. Without damaging the attached parts during the assembly process.

[Brief description of drawings]

FIG. 1 is a cross-sectional view in a width direction showing an example of a surface protective film of the invention of claim 1.

FIG. 2 is a perspective view showing a method of temporarily attaching the surface protection film of the invention of claim 1.

FIG. 3 is a perspective view showing a temporarily attached state of the surface protective film of the invention of claim 1.

FIG. 4 is a cross-sectional view in the width direction showing an example of the surface protective film of the invention of claim 2.

FIG. 5 is an explanatory view showing a method of temporarily attaching the surface protective film of the invention of claim 2.

FIG. 6 is a cross-sectional view in the width direction showing an example of the surface protective film of the invention of claim 3.

[Explanation of symbols] 1 thermoplastic resin film 2 adhesive tape 3 thermoplastic resin film 11 adhesive layer 21 support 22 adhesive layer

Claims (5)

[Claims] 1. A surface protection film or sheet for a cathode ray tube, wherein a pressure-sensitive adhesive layer is formed along at least one end of one side of a thermoplastic resin film or sheet. 2. A part of the adhesive layer of the adhesive tape has a width of 5 to 5 along both ends of the thermoplastic resin film or sheet.
A surface protection film or sheet for a cathode ray tube, which is adhered to a width of 10 mm or more so as to be exposed to the outside of 100 mm. 3. A thermoplastic resin film or sheet having a pressure-sensitive adhesive layer formed on the entire surface on one side, and another thermoplastic resin film or sheet being laminated on the pressure-sensitive adhesive layer leaving both ends. Surface protection film or sheet for CRT. 4. The surface protection film or sheet for a cathode ray tube according to claim 1, wherein the thermoplastic resin film or sheet has a 1% modulus of 0.05 to 0.5 kg / cm. 5. The protection of a cathode ray tube, wherein the surface protection film or sheet for a cathode ray tube according to claim 1 is temporarily attached to the front surface of the cathode ray tube so that the adhesive layer does not come into contact with the front surface of the cathode ray tube. Method.