JP2002255670A - Adhesive tape for aging concrete and aging method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adhesive tape for aging concrete which covers the surface of concrete easily and surely when aging the concrete, generates no deterioration during a term necessary for the aging and, further, easily perform a removal thereof and to provide a concrete aging operation which shortens an operation time and reduces an operation load in laying the concrete, does not require a specified worker for aging such that the quality of concrete can be surely enhanced without a skilled worker only if the surface of concrete is covered with the adhesive tape and is excellent in operational efficiency. SOLUTION: This adhesive tape 5 for aging concrete comprises a substrate layer 1 and an adhesive agent layer 2 which is disposed on one surface and, therein, the maximum load F which is gained by the product of tear strength TR and thickness t of the substrate layer 1 is generally 5-40 N.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adhesive tape used for curing concrete, and more particularly, to an adhesive tape which does not deteriorate during curing of concrete and is suitable for removal treatment after curing concrete. The present invention relates to an adhesive tape for concrete curing which has an excellent tear strength and is easy to handle.

[0002]

[Background Art] Concrete can be said to be a fundamental material of society indispensable in modern times, regardless of whether it is invisible on a daily basis, such as roads, stations, buildings, etc.
Many concretes are used. It is used as a footing foundation and is the foundation of a house.
It is often used as a structural material in conjunction with rebar, and its use requires the property of concrete to maintain its strength permanently. It is important to provide a sufficiently high quality.

[0003] In order to improve the quality of concrete, and in particular to provide required strength and durability as a structural material, it is necessary to perform sufficient curing during concrete construction. Concrete curing means that the concrete has hardened sufficiently,
It is performed so that the prescribed strength is given, and it is necessary to maintain a temperature suitable for hydration of cement contained in concrete, and to maintain a wet state so that the water required for the hydration reaction of the cement is not insufficient. Is desirable. Generally, a curing period of at least one month, preferably at least three months, is required, and under favorable conditions, the longer the period, the better the quality.

If the concrete is left uncured without being cured, the surface will dry due to direct sunlight or wind, and the cement will not undergo a sufficient hydration reaction, and cracks will proceed due to high temperatures in the summer months when summer days continue. Furthermore, there is a problem that the hydration reaction of the cement becomes slow due to low temperature in winter or the like where freezing can occur, so that sufficient strength cannot be exhibited. For example, according to the Cement Association Concrete Pamphlet No. 50 (1956), when concrete is constantly left in the air without curing, the compressive strength of concrete is reduced to less than half compared to the case where the concrete is constantly wet cured. It has been reported. Further, it has been confirmed that the compressive strength is improved even after six months have passed under wet conditions. Thus, curing is a very important step in concrete construction work.

Conventionally, in curing during concrete construction, for example, a form used for concrete casting should not be removed for a long period of time, or it should be covered with a vinyl sheet for construction or sprinkled with water as much as possible. A method of preventing drying was adopted.

However, when casting concrete using a formwork, there is a tendency to remove the formwork as early as possible due to restrictions on work processes and restrictions on delivery dates. If the formwork is removed early, the concrete will be exposed directly to the open air,
As described above, the quality is degraded due to a temperature change, drying, or the like. Also, after removing the formwork, covering with a vinyl sheet for construction or spraying water regularly as a curing process is cumbersome due to an increase in the number of work processes, labor and labor are increased, and efficiency is poor. In general, since the concrete is apparently solidified, the work is reduced due to lack of knowledge and knowledge, drying cannot be completely prevented or watering is unevenly performed, and the hydration reaction is not performed uniformly. There was a problem that the quality of the concrete deteriorated without curing.

[0007] As described above, in the concrete curing operation performed to enhance the quality such as strength and durability,
There is a need for a curing method that does not require holding the formwork for a long period of time, saves labor as much as possible, and preferably shortens the construction period so that it can respond to a short delivery time. Various proposals have conventionally been made in response to such circumstances.

According to Japanese Patent Application Laid-Open No. 9-158472, a method for curing concrete using a sheet has been proposed. In this method, as shown in FIG.
And a curing sheet 14 composed of a pair of water-impermeable adhesive films 17 and 18 arranged on both sides so as to sandwich it,
The cured sheet 14 is attached to the inner surface of the formwork 10 and the concrete body 16 is cast therein.
6 This is a method of leaving the product in a bonded state without peeling it off from the surface. According to such a curing method, the curing sheet 14 remains firmly on the surface of the concrete body 16 even after the mold 10 is removed, and the curing sheet 14 has both heat insulation and water impermeability. It is stated that the concrete body 16 can be prevented from drying due to temperature changes such as insolation in the hot weather or low temperature in the middle of the cold and can maintain a wet state, and as a result, good quality can be given to concrete.

[0009] However, as disclosed, this method requires that the adhesive force between the mold and the adhesive film be selected to be lower than the adhesive force between the adhesive film and the concrete. If the adhesive strength between the frame and the adhesive film is weakened, the curing sheet is displaced at the time of placing the concrete, and there is a problem that the concrete surface cannot be effectively protected and cured. On the other hand, if the adhesive force between the mold and the adhesive film is increased, the adhesive film is peeled off when the mold is removed, and there is a problem that concrete cannot be covered.

According to Japanese Patent Application Laid-Open No. 10-61184, a method for curing concrete using a sheet is also proposed. In this method, as shown in FIG. 4, a concrete body 16 is cast using a mold, and after the concrete body 16 has hardened, the mold is removed.
This is a method in which a curing sheet 24 made of a synthetic resin film 7 and a water-impermeable synthetic resin film 25 is adhered to the surface of the concrete body 16. According to such a curing method, after the mold is removed, the curing sheet 24 impermeable to moisture is attached to the concrete body 1.
It is stated that since the six surfaces are protected, the concrete body 16 can be kept wet, so that good quality can be given to the concrete.

However, this method, as disclosed, selects a photodegradable film or an alkali-degradable film as the synthetic resin film. Therefore, in practice, the curing period is controlled by the degree of sunlight. In addition, there is a problem that the concrete portion causes a shift in the deterioration time of the film, so that curing may not be sufficient depending on the location, or the film may remain, resulting in deterioration of the appearance.

[0012]

[Problems to be solved by the invention]
In the concrete curing work, long-term holding of the formwork to improve the quality such as strength and durability is not preferable from the viewpoint of the work site and restrictions on the delivery date. Therefore, it was considered to be a desirable method to adopt a method of covering the concrete surface in some way as a curing step after removing the formwork as in the above proposal. The challenge is to cover the concrete surface,
The purpose was to apply a material that could be handled easily and fulfilled the role of maintaining the moist state to improve the quality of concrete for a desired period of time.

The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to make it possible to easily and reliably cover a concrete surface when curing the concrete. In, and to provide a pressure-sensitive adhesive tape for concrete curing that does not deteriorate during a period necessary for curing, and that can be easily removed.
This requires special curing work, such as shortening the work time and work load when laying concrete, as long as the concrete surface is covered, even non-experts can surely improve the quality of concrete. The object is to realize concrete curing work with excellent work efficiency.

[0014] The present inventors have arranged the problems of the conventional sheet for covering a concrete surface, and as a result of various studies, have found that a plastic film such as polypropylene that is hardly deteriorated by light and pH fluctuation and has no water permeability. Using a moderately thin film, it is excellent in handleability of the film and workability at the time of sticking, and while keeping costs down, large tears that are difficult to tear or separate even if a tear occurs temporarily when removing It has been found that the above object can be achieved by a concrete curing adhesive tape having strength and a curing method using the adhesive tape.

[0015]

Means for Solving the Problems According to the present invention, there is provided an adhesive tape which is used at the time of curing of concrete and covers the surface of concrete, comprising at least a base material layer and one surface of the base material layer. Wherein the maximum load F of the substrate layer, which is determined by the product of the tear strength TR and the thickness t, is approximately 5 to 40 N. Tape is provided. The tear strength TR is preferably defined as the smaller one of the MD-direction tear strength and the CD-direction tear strength.

Further, according to the present invention, concrete is poured into a formwork, the formwork is removed after the placed concrete is hardened, and the hardened concrete is left for a predetermined period in a state where the surface of the hardened concrete is covered with an adhesive tape. A method for curing concrete, comprising, as an adhesive tape, at least a base layer and an adhesive layer provided on one surface of the base layer, and the tear strength TR and the thickness of the base layer A concrete curing method is provided, wherein a concrete curing adhesive tape is used, wherein a maximum load F obtained by multiplying by t is approximately 5 to 40 N. The tear strength TR is MD
The tear strength in the CD direction or the tear strength in the CD direction is preferably defined as the smaller one.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the pressure-sensitive adhesive tape for concrete curing of the present invention will be specifically described, but the present invention is not construed as being limited to these, and the present invention is not limited thereto. Various changes, modifications, and improvements may be made based on the knowledge of those skilled in the art without departing from the scope. The present invention relates to an adhesive tape for concrete curing which is used to cover the surface of concrete, protect the concrete for a predetermined period of time, keep the concrete wet, and improve the quality of the concrete. It is. It may be in the form of a sheet or a roll, and its form is not limited.

In the present invention, concrete refers to a mixed material in which dissimilar materials are combined, and as long as it is a mixed material that requires curing for a predetermined period, individual materials contained in concrete are not limited. The adhesive tape for concrete curing of the present invention, for example, Portland cement, and cement such as mixed cement comprising silica and the like,
It can be suitably used for curing various well-known concretes composed of aggregates such as sand and gravel, admixtures such as water reducing agents, and water.

The pressure-sensitive adhesive tape for concrete curing of the present invention comprises at least a base material layer and a pressure-sensitive adhesive layer. Before use, a release liner is preferably provided on the surface of the pressure-sensitive adhesive layer of the pressure-sensitive adhesive tape. In addition, it is also preferable to perform a primer treatment or a back surface treatment agent treatment as necessary.

In the present invention, as a means for peeling the adhesive tape stuck to the concrete surface after curing is completed,
The adhesive tape itself has photodegradability and alkali degradability, so that the sheet does not peel off naturally due to sunlight or alkali components oozing out of concrete, but should be removed manually or by machine, so that it can be easily removed. The feature is that the tear strength of the adhesive tape is increased.
In general, when adhesive tape is to be peeled, it often breaks in the middle and it is necessary to turn over the adhesive part many times. When the adhesive tape has a low tear strength, the adhesive tape may be torn or separated from the tear. By increasing the tear strength of the adhesive tape,
Even if a tear occurs at the work site, it will not be torn or separated from it, and it will be possible to peel off the adhesive part at one place and pull it off without tearing on the way at once, greatly improving workability And shorten the construction period.

Further, since the adhesive tape for concrete curing of the present invention uses a material that is hardly deteriorated even outdoors, it maintains a good wet state for a desired period until the cover on the concrete surface is removed by the adhesive tape. To protect the concrete surface, so that it can be cured. The adhesive tape for curing the concrete of the present invention almost completely prevents moisture to evaporate over the entire surface of the concrete, so that a good wet state is maintained over the entire area of the concrete surface, and therefore, a concrete of good quality can be produced. It is possible to get.

In the present invention, the tear strength of the pressure-sensitive adhesive tape is defined as follows. That is, the maximum load F (N) obtained by multiplying the tear strength TR (N / m) and the thickness t (m) of the base material layer is preferably in the range of approximately 5 to 40 N (unit). May be omitted). This is expressed by the following equation: 5 <TR × t = F <40 The maximum load F per thickness t is the tear strength TR.

If the maximum load F of the base material layer is smaller than 5 N, the base material layer is apt to be torn when peeled off, and the workability such as troublesome removal of the adhesive tape is reduced, which is not suitable for short delivery work. On the other hand, in order to prevent the adhesive tape from tearing, the larger the maximum load F for tearing the adhesive tape, the better. However, the resin or the like used as a normal base material layer has a limit on the tear strength TR. Although t is increased, that is, the maximum load F is increased by increasing the thickness of the base material layer, a thick adhesive tape is difficult to handle and increases the cost, which is not practical and is not preferable.

The tear strength TR of a resin or the like used in the base layer, which will be described later, is approximately 400 kN / m or less.
It is practical that the thickness t of the base material layer is 100 μm or less. Therefore, the maximum load F of the base material layer is preferably 40 N or less.

Incidentally, the tear strength TR is determined by Japanese Industrial Standard K7.
311. The thickness t refers to the thickness of the cutout portion of the rectangular tear test piece (FIG. 5) used in the tear test.

When a resin or the like used for the base material layer is processed into a film shape or a sheet shape, the strength may vary depending on the pulling direction. In the present invention,
In consideration of the actual work of applying the adhesive tape for curing to concrete and peeling it off, it is preferable that the maximum load F of the base material layer be 5 N or more even when pulled from any direction. That is, the tear strength TR is the tear strength in the MD direction of the base material layer or CD.
The maximum load F of the substrate layer, which is determined by the product of the tear strength TR and the thickness t, may be in the range of approximately 5 to 40 N even if the tear strength in the direction is smaller. preferable.

In the present invention, it is preferable to provide a release liner for protecting the pressure-sensitive adhesive layer before use in terms of storage, transportation, and handling during operation. However, the surface of the release liner on the pressure-sensitive adhesive layer side is preferably made of silicon. It is more preferable that the release agent is treated with a release agent such as a system release agent, a long-chain alkyl-based release agent, or a fluorine-based release agent because the release property between the pressure-sensitive adhesive layer and the release liner is improved.

An epoxy resin, a vinyl copolymer having a carboxyl group, an acrylic copolymer, or the like is used to improve the adhesiveness and the adhesive durability between the base material layer and the pressure-sensitive adhesive layer. It is also preferable to provide a primer layer between them. It is also preferable to perform a back surface treatment on the opposite side of the base material layer from the pressure-sensitive adhesive layer using a release treatment agent such as a fluorine-based, long-chain alkyl-based, or silicon-based release agent.

Hereinafter, the pressure-sensitive adhesive tape for concrete curing of the present invention will be described in more detail with reference to the drawings.
FIG. 1 is a sectional view showing one embodiment of the adhesive tape for concrete curing of the present invention. As shown in FIG. 1, the adhesive tape 5 for curing concrete includes a base layer 1 and an adhesive layer 2 provided on one surface of the base layer 1. A primer layer 3 is provided between
The back surface treatment agent layer 4 is provided on the side opposite to the pressure-sensitive adhesive layer 2.
Usually, before use, a release liner is often provided on the surface of the pressure-sensitive adhesive layer 2 opposite to the base material layer 1 (not shown).

By providing the primer layer 3, when the curing of the concrete is completed and the concrete curing adhesive tape 5 is pulled to be removed,
It is possible to prevent only the base material layer 1 from peeling and the adhesive layer 2 from remaining on the concrete surface. When the pressure-sensitive adhesive layer 2 remains on the concrete surface, even if the tear strength of the base material layer 1 is large,
Workability cannot be improved. By the primer layer 3,
It is important that the base material layer 1 and the pressure-sensitive adhesive layer 2 are firmly integrated.

The surface of the release liner on the side of the pressure-sensitive adhesive layer 2 is subjected to a release agent treatment such as a treatment with a silicon-based release agent,
The releasability between the pressure-sensitive adhesive layer and the release liner is improved.
When the release liner is made of a material having good releasability, the release agent treatment may not be performed.

Now, an example of a method for producing the adhesive tape 5 for curing concrete shown in FIG. 1 will be described below. First, a film made of an olefin resin such as polypropylene or polyethylene, or a polyester resin and having a predetermined thickness and a desired tear strength is prepared. Preferably, on one side of this film, an acrylic resin, a vinyl copolymer, or a rubber-based resin, a primer made of a polyester resin or the like is applied and dried, and then, on the primer, an acrylic-based, rubber-based, silicone-based An adhesive made of a resin or a fluorine resin is applied. On the surface of the film opposite to the surface on which the pressure-sensitive adhesive is applied, preferably, a long-chain alkyl-based release agent, a silicon-based release agent, or a back surface treatment agent comprising a fluorine-based release agent is applied, and the concrete curing of the present invention is applied. The adhesive tape 5 for use is obtained.

Next, a method for curing concrete using the adhesive tape for concrete curing of the present invention will be described. FIG. 2 is a cross-sectional view illustrating an example of the curing method, and shows an example in which the adhesive tape 5 for concrete curing of the present invention is applied to a concrete body 6 having a vertical wall surface.

A concrete form 6 is formed by placing a formwork (not shown) and pouring concrete into the formwork. When the concrete body 6 has solidified and the strength has reached a predetermined value, the mold is removed, and the adhesive tape 5 for concrete curing is attached so as to cover the open entire surface. FIG. 2 shows a state after the concrete curing adhesive tape 5 has been attached to the concrete body 6. It is preferable that the adhesive tape 5 for concrete curing be adhered to a large area at a time without cutting.

The base layer of the adhesive tape 5 for curing concrete prevents moisture from evaporating from the surface of the concrete body 6, and keeps the concrete body 6 in a good wet state suitable for curing. Then, while leaving the adhesive tape 5 for concrete curing on the surface, the concrete body 6
After curing for a predetermined period, the concrete curing adhesive tape 5 is peeled off from the concrete body 6 to complete the curing. Concrete body 6 kept in good wet condition
In addition, the adhesive tape 5 for concrete curing can be easily removed because the adhesive tape 5 for concrete curing hardly tears during the pulling.

Hereinafter, the constituent materials of the adhesive tape for concrete curing according to the present invention will be described. As described above, the adhesive tape for concrete curing is composed of at least the base material layer and the adhesive layer. The pressure-sensitive adhesive layer is for bonding concrete and the base material layer, and the base material layer,
The type is not particularly limited as long as it has good adhesiveness to the concrete and the tackiness is not lost by the alkali component diffused from the curing concrete. In general, a solvent-based acrylic adhesive, a solvent-based natural rubber-based adhesive, a solvent-based block copolymer-based adhesive, an emulsion-based acrylic adhesive, a hot-melt-based acrylic adhesive, and the like can be used. In terms of durability,
It is preferable to use an acrylic pressure-sensitive adhesive. The thickness of the pressure-sensitive adhesive layer is not limited, but generally 10 to 100 μm
It is about.

The base material layer is used to prevent moisture from evaporating from the concrete, and therefore, the type of the base material layer is not particularly limited as long as the evaporated moisture does not pass therethrough. Usually, plastic films such as olefin resins such as polypropylene and polyethylene, polyethylene terephthalate, and polyvinyl chloride can be used.

Although the thickness of the base material layer is not limited, it is generally about 20 to 150 μm, and is more preferably about 25 to 100 μm because strength and cost are not required. The color of the base material layer is not limited, such as white, black, milky white, transparent, etc., but in the dark color, sunlight is concentrated and concentrated, the concrete surface temperature under the tape varies, and curing is performed uniformly. White or milky white is preferred because it may not be present and if it is transparent, it may be forgotten to remove it.

The release liner provided on the pressure-sensitive adhesive layer of the adhesive tape for concrete curing and removed when the tape is used may be a release liner or release paper generally used for an adhesive tape. . The release liner needs to be able to be easily manufactured into a roll shape, a sheet shape, or the like without deteriorating the adhesive properties of the pressure-sensitive adhesive, and is composed of a substrate that is easily peeled off from the pressure-sensitive adhesive. The type of the base material is not particularly limited as long as it can be easily produced in a roll shape, a sheet shape, or the like without lowering the adhesive properties of the adhesive. Paper such as crecord paper and Japanese paper, and woven fabric made of fibers such as rayon, polyester, nylon, and acrylic are used.
In addition, depending on the type of the adhesive, when the release effect between the release liner and the adhesive (for example, an olefin resin such as polypropylene and polyethylene), a release agent is not necessary,
In other cases, it is preferable to perform a release agent treatment on the surface in contact with the pressure-sensitive adhesive layer.

[0040]

EXAMPLES Hereinafter, the present invention will be described based on examples, but the present invention is not limited to these examples. (Example 1) A polyolefin film (FLJ-4002 manufactured by 3M) having a thickness of 80 µm was prepared as a base material layer.
When the tear strength of this film was measured according to Japanese Industrial Standard K7311, it was 164 kN / m in the MD direction and 113 kN / m in the CD direction.

After an acrylic primer was applied to the base layer at 0.3 μm, an acrylic pressure-sensitive adhesive (Denacol EX-421 manufactured by Nagase Kasei Co., Ltd. was added in an amount of 2 parts by weight per 100 parts by weight of TM-287 manufactured by Toagosei Co., Ltd.). Was added so that the thickness after drying was 30 μm. Then, 0.2 μm of a long-chain alkyl-based back surface treatment agent was applied to the surface of the base material layer opposite to the primer and the pressure-sensitive adhesive to obtain a pressure-sensitive adhesive tape for concrete curing.

Using the obtained adhesive tape for concrete curing, the concrete body was affixed to the concrete body from which the solidified form was removed, and the concrete body was cured. Curing was performed for three months, and then the adhesive tape for concrete curing was peeled off from the concrete body. The peelability was good and the tape could be easily removed without tearing. Table 1 shows the specifications and tear test results of the base layer of the used adhesive tape for concrete curing, and the ease of peeling of the adhesive tape for concrete curing after curing.

(Examples 2 to 5, Comparative Examples 1 to 3) The concrete body was cured under the same conditions as in Example 1 except that the material used for the base layer of the adhesive tape for concrete curing was changed. Of the adhesive tape for concrete curing was evaluated. Table 1 shows the specifications and tear test results of the base layer of the used adhesive tape for concrete curing, and the ease of peeling of the adhesive tape for concrete curing after curing.

In Table 1, PE is polyethylene, PP is polypropylene, PET is polyethylene terephthalate, PP / PE is a mixed resin in which the mixing ratio of PP and PE is 60:40 by weight, and EVA is EVA. Is ethylene-
1 shows a vinyl acetate copolymer. In addition, the ease of peeling is indicated by ○, and the cross indicates that the tape was frequently torn during the peeling, and it was difficult to remove all the tape. In addition, the material which comprises the concrete body used in each Example and each comparative example is Portland cement as a cement, gravel and sand as an aggregate, an AE water reducing agent as an admixture, and water. or,
The mixing ratio of cement, gravel, sand, admixture, and water is 25: 32: 32: 0.2: 11, respectively. In each of the examples and the comparative examples, the cured concrete body had a compressive strength of 40 N / mm ² or more, and had good quality as the concrete body.

[0045]

[Table 1]

(Tear Test) The tear test was conducted according to Japanese Industrial Standard K.
7311 (1995). The following describes the tear test method. The base material layer as a test piece is a right-angled tear test piece shown in FIG. 5 which is formed by punching. MD direction (flow direction of raw film)
When measuring the tear strength of
When measuring the tear strength in the CD direction (the width direction of the film raw material) in the D direction, the long direction of the test piece is the CD direction. The thickness t (m) of the notch portion of the test piece was measured, and the test piece was attached to a tensile tester, and a tensile speed of 300 ±
At 15 mm / min, pull until the test piece breaks,
Read and record the maximum load F (N) of the tester up to the rupture. The test is performed on three test pieces, and the average value is used as the test result. The tear strength TR (N / m) is determined by the following equation: TR = F / t.

(Consideration) As can be seen from Table 1, in Examples 1 to 5 using the pressure-sensitive adhesive tape for concrete curing of the present invention, the ease of peeling of the tape after curing was good, but that of Comparative Example With tapes 1 to 3, when the tape was to be removed after curing, the tape was easily torn and the peelability was not good.

[0048]

As described above, according to the pressure-sensitive adhesive tape for concrete curing of the present invention, it can be easily adhered to the surface of concrete, curing is completed, and the pressure-sensitive adhesive tape for concrete curing is peeled off from the surface of concrete. In this case, the handling and the operation are easy, and the adhesive tape itself does not deteriorate during curing, and does not cause evaporation and diffusion of water. Therefore, even if you are not an expert,
It has an excellent effect that high-quality concrete with sufficient strength and durability can be obtained. Public buildings such as roads, train stations, buildings, or private homes made of concrete with such high reliability provide long-term safety and security for people, and minimize secondary disasters during earthquakes. Can be suppressed.

[Brief description of the drawings]

FIG. 1 is a sectional view showing one embodiment of an adhesive tape for concrete curing of the present invention.

FIG. 2 is a sectional view illustrating an example of a curing method using the adhesive tape for concrete curing of the present invention.

FIG. 3 is a cross-sectional view showing an example of a conventional curing sheet.

FIG. 4 is a cross-sectional view showing another example of a conventional curing sheet.

FIG. 5 is a top view showing the shape of a test piece used for a tear test.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Base material layer, 2 ... Adhesive layer, 3 ... Primer layer, 4 ... Back surface treatment agent layer, 5 ... Adhesive tape for concrete curing, 6,
16 ... concrete body, 10 ... formwork, 12 ... support, 1
4, 24: curing sheet, 15: heat insulating member, 17, 18, ...
Adhesive film, 25: synthetic resin film, 27: adhesive.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Norihito Kondo 3-8-8 Minamihashimoto, Sagamihara-shi, Kanagawa F-term in Sumitomo 3M Limited (reference) 2E172 EA02 4G012 RB02

Claims (4)

[Claims] 1. An adhesive tape used for curing concrete and covering the surface of concrete, comprising at least a base material layer and an adhesive layer provided on one surface of the base material layer, The maximum load F of the substrate layer, which is determined by the product of the tear strength TR and the thickness t, is approximately 5 to 40.
N is an adhesive tape for concrete curing. 2. The method according to claim 1, wherein the tear strength TR is the MD of the base material layer.
The pressure-sensitive adhesive tape for concrete curing according to claim 1, which is the smaller one of the tear strength in the CD direction and the tear strength in the CD direction. 3. A method for curing concrete in which concrete is poured into a formwork, and after the poured concrete has hardened, the formwork is removed and the surface of the hardened concrete is covered with an adhesive tape for a predetermined period of time. In the pressure-sensitive adhesive tape, at least, a base layer, a pressure-sensitive adhesive layer provided on one surface of the base layer, the tear strength TR and thickness t of the base layer, A concrete curing method characterized by using a concrete curing adhesive tape, wherein the maximum load F obtained by the product of the above is approximately 5 to 40 N. 4. The method according to claim 1, wherein the tear strength TR is the MD of the base material layer.
The method for curing concrete according to claim 3, wherein the smaller one of the tear strength in the CD direction and the tear strength in the CD direction.