JPH11333993A - Ageing sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ageing sheet used for covering an equipment article to protect the same, capable of being bonded to the equipment, not extremely lowered in tackiness even if bonding and separation are repeated, not generating size remaining at a time of separation and not almost lowered in tackiness even by washing. SOLUTION: In an ageing sheet wherein a self-bonding layer 3 is formed on the rear surface a vinyl chloride resin foam layer 1 through an intermediate layer 2 (a mixed resin layer of a vinyl chloride resin and an ethylene/vinyl acetate copolymer resin or a single resin layer of an ethylene/vinyl acetate copolymer resin) based on EVA, a self-bonding layer of an acrylic resin having self-bonding strength 1/4 or more the first self-bonding strength even after the bonding and separation to a coated steel panel is repeated five times is formed as the self-bonding layer 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a curing sheet for protecting equipment made of painted steel plate or the like during construction.

[0002]

2. Description of the Related Art Switchboards in buildings and factories are generally manufactured using painted steel plates or the like. If work is performed around such a switchboard, the switchboard and surrounding equipment may be damaged by the impact of construction materials.Therefore, blue sheets that are usually used as covering materials at construction sites, etc. Using a protective sheet called, the switchboard and surrounding equipment are covered and protected.

[0003]

However, since the conventional blue sheet is used simply by covering the equipment, or partially temporarily fixed with an adhesive tape, the blue sheet moves during the operation. There is a problem that the equipment is easily exposed due to being turned or turned up, and it is difficult to sufficiently cover and protect the equipment.

Moreover, since the conventional blue sheet is thin and inferior in shock absorption, there is a problem that even if the blue sheet is covered with equipment, the equipment is liable to be damaged by an external object. The blue sheet was liable to burn due to welding sparks and the like, and there was also a risk of fire.

The present invention relates to a curing sheet which can solve the above-mentioned problems and can be applied to equipment and the like. Even if the application and the peeling are repeated, the adhesive strength is not extremely reduced. The purpose of the present invention is to provide a cured sheet which does not cause "residual" and hardly loses its adhesive strength even when washed with water.

[0006]

In order to achieve the above object, a curing sheet according to claim 1 of the present invention comprises a vinyl chloride resin foam layer and a vinyl chloride resin and an ethylene-vinyl acetate copolymer resin. A cured sheet in which an adhesive layer is formed via a mixed resin layer or a single resin layer of an ethylene-vinyl acetate copolymer resin (hereinafter, referred to as an EVA-based intermediate layer), wherein the adhesive layer is attached to a coated steel sheet. 5 peels
An acrylic resin adhesive layer having an adhesive strength of 1/4 or more of the initial adhesive strength even after repeated times.

The cured sheet according to claim 2 of the present invention is the cured sheet according to claim 1, wherein the vinyl chloride resin foam layer has an apparent specific gravity of 0.5 to 0.65 g / cm ^3. The curing sheet according to claim 3, wherein the thickness of the intermediate layer mainly composed of EVA is 0.1 to 0.5 mm. is there.

The curing sheet according to claim 1 of the present invention has a pressure-sensitive adhesive layer formed on the back surface of a foamed vinyl chloride resin layer through an intermediate layer mainly composed of EVA. Can be applied to cover and protect, and there is no need to worry about moving or rolling like a conventional blue sheet. Moreover, this adhesive layer is an acrylic resin adhesive layer having an adhesive strength of 1/4 or more of the initial adhesive strength even after repeating the application and peeling to the coated steel sheet five times,
Even if the application and the peeling are repeated, the decrease in the adhesive strength is small, so that the curing sheet does not peel off by its own weight even when used repeatedly 20 times as described later.

Further, since the intermediate layer mainly composed of EVA has an excellent bonding force to both the vinyl chloride resin foam layer and the adhesive layer made of acrylic resin, the intermediate layer mainly composed of EVA is interposed therebetween. The curing sheet according to claim 1, wherein the adhesive layer is formed on the back surface of the vinyl chloride resin foam layer, has a large peel strength of the adhesive layer. Therefore, when the curing sheet attached to the equipment is peeled off, the so-called “adhesive residue” in which the adhesive layer is peeled off and remains on the surface of the equipment does not occur. In addition, the above EVA
When the adhesive layer is formed with a main intermediate layer interposed, the adhesive strength hardly decreases even if the cured sheet is washed with water, so that it can be washed with water. The thickness of the intermediate layer mainly composed of EVA is suitably in the range of 0.1 to 0.5 mm as in the curing sheet of the third aspect.

[0010] Furthermore, since the vinyl chloride resin foam layer is self-extinguishing, there is no fear that it will spread even if the welding sparks fly. Moreover, since the foam layer has good shock absorption properties, even if it hits with an object, it will not be shocked. To protect the equipment. In particular, as in claim 2, the apparent specific gravity is 0.5 to
A cured sheet using a foamed vinyl chloride resin layer having a thickness of 0.65 g / cm ³ and a thickness of 1.0 to 2.5 mm requires equipment equipment because the foamed layer has excellent shock absorption and an appropriate thickness. Since it can be sufficiently protected and has good flexibility and bendability, it can be covered and affixed along irregularities on the surface of the equipment.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic cross-sectional view of a curing sheet according to the present invention. As shown, the curing sheet has an adhesive layer on the back surface of a vinyl chloride resin foam layer 1 with an intermediate layer 2 mainly composed of EVA. 3 is a sheet having a three-layer structure in which No. 3 is formed.

The foamed vinyl chloride resin layer 1 has a thickness of 0.5 to 0.1 mm.
Thickness 1.0 to 2 having an apparent specific gravity of 65 g / cm ^3.
5 mm foam layer, in which D
It contains 20 to 30% by weight of OP, and contains an inorganic filler such as calcium carbonate as a filler. Further, pigments such as titanium oxide and carbon and stabilizers are also contained in appropriate amounts.

The foamed vinyl chloride resin layer having an apparent specific gravity of more than 0.65 g / cm ³ is inferior in shock absorption (cushioning property), flexibility, flexibility and the like, and has an apparent specific gravity of more than 0.5 g / cm ³ . The small vinyl chloride resin foam layer
Any of them are unsuitable as the vinyl chloride resin foam layer 1 of the curing sheet because they are too flexible and have low strength to hardly protect the equipment.

A vinyl chloride resin foam layer having a thickness of less than 1 mm is too thin to absorb a shock sufficiently, while a vinyl chloride resin foam layer having a thickness of more than 2.5 mm has flexibility and flexibility. However, it is difficult to apply it along the unevenness of the surface of the equipment because of its reduced property, and it is still unsuitable as the foamed vinyl chloride resin layer 1 of the curing sheet.

The plasticizer DOP is blended to give the vinyl chloride resin foam layer 1 an appropriate degree of flexibility, and if the blending amount is less than 15% by weight, the foam layer 1 Insufficient flexibility makes it difficult to adhere along the irregularities of the equipment. On the other hand, if the amount is more than 35% by weight, the vinyl chloride resin foam layer 1 becomes too soft and the The bleed-out on the surface of the layer 1 causes an inconvenience that stickiness becomes severe.

Further, an inorganic filler such as calcium carbonate is compounded to reduce thermal expansion and contraction at the same time as increasing the amount.

As described above, since the foamed vinyl chloride resin layer 1 containing a large amount of DOP is inferior in adhesion (adhesion) to the adhesive layer 3 made of an acrylic resin, the adhesive layer 3 is formed of the foamed vinyl chloride resin layer 1. If it is formed directly on the back surface, it is difficult to make the adhesive layer 3 strongly adhere (adhere). Therefore, in this cured sheet, the EVA-based intermediate layer 2 having excellent adhesion (adhesion) to both the vinyl chloride resin foam layer 1 and the acrylic resin adhesive layer 3, that is, the vinyl chloride resin Ethylene-vinyl acetate copolymer resin (hereinafter referred to as EVA)
By forming a mixed resin layer or a single resin layer of EVA on the back surface of the vinyl chloride resin foam layer 1 and forming the adhesive layer 3 via the intermediate layer 2 mainly composed of EVA, the adhesive layer 3
To increase the peel strength of the adhesive layer 3,
When removing the curing sheet attached to the equipment, the adhesive layer 3
Does not adhere to the surface of the equipment and cause so-called “adhesive residue”.

A curing sheet in which the acrylic resin adhesive layer 3 is directly formed on the back surface of the vinyl chloride resin foam layer 1 is as follows:
When washed with water, the adhesive strength of the adhesive layer 3 is reduced, and the adhesive layer 3 is easily detached from the vinyl chloride resin foam layer 1. Therefore, washing with water is impossible. However, when the EVA-based intermediate layer 2 is interposed, an acrylic resin adhesive layer is used. Since the adhesive layer 3 is firmly adhered, the adhesive layer 3 does not come off even after washing with water, and the adhesive strength is almost restored to the original state when there is no moisture, so that the adhesive layer 3 can be reused.

The mixing ratio of the vinyl chloride resin and EVA in the intermediate layer 2 mainly composed of EVA is 0: 100 to 2 by weight.
When the ratio of EVA is lower than the above range, the flexibility of the intermediate layer 2 mainly composed of EVA is reduced, so that it is difficult to obtain a cured sheet having good flexibility and flexibility. .

The EVA-based intermediate layer 2 contains 20 to 30% by weight of a plasticizer such as DOP in the vinyl chloride resin, so that the vinyl chloride resin retains its softness. If the amount is too large, bleeding occurs on the surface, which may adversely affect the adhesive layer 3.

The thickness of the intermediate layer 2 mainly composed of EVA is 0.1 to
It is appropriate to be within the range of 0.5 mm, and 0.1 mm
If the thickness is thinner, the adhesive layer 3 is easily peeled off, which causes inconvenience such as adhesive residue on equipment. If the thickness is more than 0.5 mm, inconvenience such as reduced flame retardancy occurs.

The adhesive layer 3 is an acrylic resin adhesive layer having an adhesive strength not less than 1/4 of the initial adhesive strength even after repeating the application and peeling to the coated steel sheet five times. Even if it is repeated several times, the curing sheet maintains its adhesive strength such that it does not peel off from the coated steel sheet by its own weight.

More specifically, the adhesive layer 3 has an initial adhesive strength of about 20 to 120 gf / 25 mm in a 90-degree peel test according to JIS Z 0237 described later. An adhesive layer having an initial adhesive strength of less than 20 gf / 25 mm, for example, an adhesive layer of about 5 gf / 25 mm,
Before repeating the pasting and peeling 20 times, the adhesive strength decreases and the curing sheet comes off under its own weight, while the initial adhesive strength is greater than 120 gf / 25 mm,
For example, an adhesive layer having a thickness of about 500 gf / 25 mm has too strong an adhesive force, so that the cured sheet may not be easily peeled off and adhesive residue may be left, which is not preferable.

In particular, the adhesive layer 3 of an acrylic resin having a relatively high crosslink density and containing a large amount of an acrylate having a high glass transition point and having a small tackiness and a small tackiness is preferable.
The soft adhesive layer with a large tack adheres in a state where the dust is entangled with the adhesive layer, so it is difficult for the dust to fall off even when washed with water, but the slightly harder adhesive layer with less tack simply attaches the dust to the adhesive layer The garbage can be easily washed away with water, because it does not get entangled.

It is sufficient that the thickness of the adhesive layer 3 is about 50 to 150 μm.

[0027] The curing sheet having the above structure is used, for example, when performing plumbing work around a switchboard of a building or a factory.
It is put on a switchboard made of painted steel plate or the like and peripheral equipment, and is attached with the adhesive force of the adhesive layer 3. When the curing sheet is attached to equipment such as a switchboard in this manner, the equipment does not move or roll up as in the case of a conventional blue sheet, so that equipment can be sufficiently covered and protected. As described above, since the adhesive layer 3 has a small decrease in adhesive strength even after repeated application and peeling, the curing sheet does not fall off from the equipment by its own weight even when used repeatedly. , Can be securely attached.

Further, in this cured sheet, since the vinyl chloride resin foam layer 1 is self-extinguishing, there is no fear that it will spread even if welding sparks adhere, and the foam layer 1 has good shock absorbing properties. It is possible to absorb the impact even if the object hits and to protect the equipment sufficiently, and because it has good flexibility and flexibility, it can fit along the unevenness of the surface of the equipment. Can be coated and affixed.

Further, in this curing sheet, since the peel strength of the adhesive layer 3 is increased by interposing the intermediate layer 2 mainly composed of EVA, "paste residue" may occur when the curing sheet is peeled off from the equipment. In addition, even if it is washed with water, the adhered dust can be easily washed away without lowering of the adhesive strength or detachment of the adhesive layer 3.

Next, more specific examples and comparative examples of the present invention will be described.

Example 1 A resin sheet mixed with a vinyl chloride resin and EVA (using a vinyl acetate content of 40%) (thickness: about 0.3 mm, vinyl chloride resin and EV)
A resin mixture containing a foaming agent was applied on a base sheet having a mixing ratio of 1: 9) with the resin A, and the paste was passed through a heating furnace at a predetermined temperature to give a thickness of about 2 mm and an apparent specific gravity of 0.1. A laminated sheet of a vinyl chloride resin foam sheet of 58 g / cm ³ and the above-mentioned mixed resin sheet (an EVA-based sheet) was prepared. Then, a thickness of about 0.1 m is formed on the surface of the mixed resin sheet (sheet mainly composed of EVA) of the laminated sheet.
m of an acrylic resin adhesive layer was formed with a roll coater to produce a cured sheet having an overall thickness of about 2.4 mm.

[0032] This curing sheet is JIS Z 0
A peel test according to 237 was performed, and the adhesive strength was measured. That is, the cured sheet cut to a width of 25 mm was adhered to the coated steel sheet, and after 1 hour, the cured sheet was peeled off at a crosshead speed of 200 mm / min by 90 degrees, and the initial adhesive strength was measured. As a result, the initial adhesive strength was 40 gf / 25 mm as shown in Table 1 below, and no adhesive residue was observed.

According to the same test method as above, sticking and peeling to a coated steel sheet were repeated five times, and the adhesive strength of the cured sheet was measured each time, and the presence or absence of adhesive residue was examined. The results are shown in Table 1 below.

Next, the cured sheet cut to a width of 25 mm was adhered to a coated steel plate and left for 3 days, left for 7 days, left for 1 month, and peeled and pasted by the same test method as described above. The test was repeated five more times, and the adhesive strength of the cured sheet was measured each time, and at the same time, the presence or absence of adhesive residue was examined. The results are shown in Table 1 below.

Further, when the hardness and the flammability of the cured sheet were examined, the results shown in Table 1 below were obtained. Hardness was measured by JIS K-7215, type A method 3
The average values for one sample are shown, and the flammability is UL-94, HF for five samples.
-1 was measured based on the method of -1, wherein the carbonization distance was an average value of five samples, the after-flame time and the residual dust time were both 0 seconds, and there was no dripping matter combustion. Met.

Example 2 The cured sheet prepared in Example 1 was cut to a width of 25 mm, washed with water, dried, pasted on a coated steel plate, left for 1 hour, and left for 3 days. , For 7 days, and for 1 month, the peeling and sticking were repeated 5 times by the same test method as in Example 1, and the adhesive strength of the cured sheet was measured each time. Examined. The results are shown in Table 1 below.

[Table 1]

According to Table 1, the initial adhesive strength of the cured sheet of Example 1 which was not washed with water was 40 gf / 25 mm.
It is a moderate value that is neither too strong nor too weak. And the adhesive strength at the time of repeating sticking and peeling 5 times is 20.
gf / 25 mm, which indicates that the adhesive strength was maintained at １ ／ of the initial adhesive strength, and that the decrease in adhesive strength was small. In addition, those left for 3 days after application, those left for 7 days, and those left for one month have slightly increased initial adhesive strength. Is in the range of about 1/3 to about 1/4 of the adhesive strength, and it can be seen that the decrease in the adhesive strength is small.

The cured sheet of Example 2 washed with water also has an initial adhesive strength of 38 gf / 25 mm, and has almost the same adhesive strength as the cured sheet of Example 1 not washed with water. And the adhesive strength at the time of repeating sticking and peeling 5 times is 19 gf / 25 mm, maintaining the adhesive strength of 1/2 of the initial adhesive strength, and it turns out that the adhesive strength is hardly reduced. Also, as with the cured sheet of Example 2 which was washed with water, as with the cured sheet of Example 1, which was not washed with water, as the number of days left after application increased, the initial adhesive strength gradually increased, but was left for 3 days after application. What was done, what was left for 7 days, what was left for 1 month, the adhesive strength at the time of the fifth peeling was about 1/3 of the initial adhesive strength.
It is in the range of about 1/4, and it can be seen that the decrease in the adhesive strength is small as in the cured sheet of Example 1.

The cured sheet of Example 1 has a hardness of 51.7 and a suitable cushioning property, and therefore has a good shock absorption and can be sufficiently protected so as not to damage equipment. You can see that. Then, looking at the results of the flammability test, the carbonization distance was 27.6 mm, the afterflame time was 0 seconds, the residual dust time was 0 seconds, and there was no dripping material burning,
It can be seen that the sheet conforms to UL-94 and HF-1 standards and does not spread even if welding sparks or the like are attached.

[0040]

As is clear from the above description, the cured sheet of the present invention can be sufficiently protected by covering and affixing the equipment made of painted steel plate or the like, It does not spread even if the sparks etc. scatter, it has a suitable adhesive strength, it is easy to peel off, there is no adhesive residue, and even if it is repeatedly applied and peeled, the adhesive strength is small, so it can be used repeatedly, It has a remarkable effect that it can be washed with water when it gets dirty.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a curing sheet according to the present invention.

[Explanation of symbols]

 Reference Signs List 1 vinyl chloride resin foam layer 2 EVA-based intermediate layer 3 adhesive layer

Claims (3)

[Claims] 1. A mixed resin layer of a vinyl chloride resin and an ethylene-vinyl acetate copolymer resin or a single resin layer of an ethylene-vinyl acetate copolymer resin (hereinafter referred to as an EVA-based intermediate layer) The adhesive sheet has a pressure-sensitive adhesive strength of 1/4 or more of the initial pressure-sensitive adhesive strength even after repeating the application and peeling to the coated steel sheet five times. A curing sheet, characterized in that it is an acrylic resin adhesive layer. 2. A foamed vinyl chloride resin layer having a thickness of 0.5 to 0.6.
Thickness of 1.0 to 2.5 with an apparent specific gravity of 5 g / cm ³
The curing sheet according to claim 1, which is a foam layer having a thickness of 1 mm. 3. An intermediate layer mainly composed of EVA having a thickness of 0.1-0.
The curing sheet according to claim 1 or 2, which is 5 mm.