JP2001031919A - Tape and pressure-sensitive adhesive tape - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a tape and a pressure-sensitive adhesive tape each of which can be incinerated without forming noxious gases and each of which has an improved performance of protecting the objects bundled therewith by forming an olefin resin film having a specified MD tensile modulus, a specified MD stress, and a specified MD residual stress into a tape. SOLUTION: This tape is formed from an olefin resin film having the following properties: an MD tensile modulus of 150-1,500 kgf/cm2, having no yield point when elongated in the MD, having a stress of 50-300 kgf/cm2 when elongated by 50% in the MD, and having a residual stress of 25-160 kgf/cm2 after 1 min after a 50% elongation in the MD. The tape is produced by forming a film of a polypropylene resin having resin eluate amounts of 40-70 wt.%, based on the total polypropylene resin, at 0 deg.C, of 10-30 wt.% at above 0 to 70 deg.C, and of 20-40 wt.% at above 70 deg.C as measured by cross fractionation and stretching the film at a ratio of 1.1-5 at 60-150 deg.C in the MD or TD.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tape and an adhesive tape, and more particularly to a tape and an adhesive tape used for binding or protecting an air conditioner pipe.

[0002]

2. Description of the Related Art A method in which a tape is spirally wound around a bandage for the purpose of binding and protecting electric wires, pipes, tubes, and the like, and the end of the winding or both ends of the beginning and end of the winding are fixed with an adhesive tape. Is widely practiced. In this method, for example, in a pipe connecting an indoor unit and an outdoor unit of an air conditioner, (1) a copper pipe coated with a heat insulating foam for sending a working fluid from the indoor unit to the outdoor unit, (2) a pipe from the outdoor unit to the indoor unit Bundling and protecting a collection of copper tubes coated with insulating foam that returns the working fluid, (3) covered electric wires that supply power to drive the outdoor unit, and (4) tubes that drain condensed water from the indoor unit For this purpose, a tape made of a soft vinyl chloride resin is spirally wound, and the end of the winding or both the beginning and the end of the winding are fixed with an adhesive tape.

[0003] Such a tape made of a soft vinyl chloride resin has flexibility and is easily stretched, so that it can follow the irregularities of the above-mentioned material to be bound well, and since it has no yield point when stretched, it is a colored tape. Will not whiten and impair the appearance,
Since it has a moderate residual stress at the time of elongation, the objects to be tied can be effectively tied. If the residual stress at the time of binding is small, the binding may be loosened, and if it is large, the heat insulating foam may be crushed. On the other hand, the tape made of a soft vinyl chloride resin has an appropriate residual stress due to the relaxation of the stress at the time of binding, so that the binding is not loosened and the heat insulating foam is not crushed and cut by pulling by hand. Therefore, it was suitable for the above use.

[0004] However, a tape made of a soft vinyl chloride resin generates harmful gas when incinerated, which is not preferable from an environmental point of view. Therefore, development of a tape other than the soft vinyl chloride resin and suitable for the above use is desired. As a tape which is flexible and easily stretched without generating harmful substances by incineration and which has an appropriate residual stress and strength at the time of stretching, for example, JP-A-51-107871 and JP-A-51-1078.
No. 72 proposes a stretchable tape combining rubber and a stretchable woven fabric. However, this tape is expensive because it is composed of rubber and elastic knitted fabric, and cannot be cut even if it is strongly pulled by hand.

An olefin resin is suitable as a substrate which does not generate harmful gas by incineration.
JP-A-218043 proposes an adhesive film for surface protection using a resin composed of a hard segment and a soft segment as an olefin resin as a base material. When the adhesive film is applied to a member having a three-dimensional curved surface during processing of a protected object and when the film is torn, galling, floating,
This has the effect that contamination and tearing of the protected object are less likely to occur. However, although the above adhesive film does not generate harmful gas by incineration, since it is an adhesive film for surface protection, it has a small residual stress and is not suitable for use in binding air conditioner piping and the like.

In some cases, an adhesive tape is used for bundling the above-mentioned heat insulating material for air conditioner pipes. As an adhesive tape having an olefin resin as a base material, for example, JP-A-45-3403
No. 9 proposes a resin based on a resin composition mainly composed of an ethylene-vinyl acetate copolymer. However, this adhesive tape has insufficient heat resistance, productivity in the drying process after applying the adhesive, storage at high temperatures in summer,
Since there are problems in winding workability, durability after winding, and the like, it has been difficult to use it as a substitute for vinyl tape.

[0007] Japanese Patent Application Laid-Open No. 52-100536 discloses that
(a) ethylene-α-olefin copolymer, (b) low-density polyethylene, and (c) high-density polyethylene and polypropylene, a pressure-sensitive adhesive tape based on a uniaxially stretched film of a polyolefin composition comprising at least one of: Proposed. However, this pressure-sensitive adhesive tape has the drawback that it is too hard and the relaxation of residual stress is insufficient, and when it is wound around an object to be tied, not only does it cause many "wrinkles" to impair the appearance, but also causes penetration of rainwater and the like. Therefore, it is difficult to use as a substitute for a vinyl tape because the protection performance of the binding object is insufficient.

In Japanese Patent Application Laid-Open No. 58-71975, a polypropylene layer is provided on both surfaces, and a soft resin layer having a flexural modulus at 20 ° C. of 1 × 10 ³ kg / cm ² or less is provided as an intermediate layer. An adhesive tape using a stretched laminated sheet as a base material is disclosed. However,
This base material has a drawback that when tension is applied, the soft resin of the intermediate layer protrudes from the end surface of the tape base material and becomes sticky, so that the workability is reduced, and dirt adheres, and the commercial value is significantly reduced. For this purpose, as described in this publication, it is necessary to reduce the thickness of the base material to one-fifth or less of ordinary vinyl tape. In addition, there is a problem in that the film lacks in hiding power and impairs the appearance.

Further, Japanese Patent Application Laid-Open No. 63-35678 proposes a pressure-sensitive adhesive tape having a base material obtained by stretching a sheet made of a blend of polypropylene or a polypropylene-based copolymer with a linear low-density polyethylene. Have been. However, this pressure-sensitive adhesive tape is too hard and has insufficient relaxation of residual stress, so when it is wound around an object to be tied, many "wrinkles" are generated, which not only impairs the appearance but also causes rainwater to enter, so that There is a problem that the protection performance is insufficient.

[0010]

SUMMARY OF THE INVENTION In view of the above drawbacks, an object of the present invention is to produce no harmful gas during incineration,
An object of the present invention is to provide a tape and an adhesive tape which can suitably bind electric wires, pipes, tubes, cans, and the like, particularly air conditioner piping.

[0011]

The tape of the present invention is characterized by comprising an olefin resin film having the following physical properties. (1) The tensile modulus in the MD direction is 150 to 1500 kgf /
cm ² , (2) no yield point when stretched in the MD direction, (3) stress of 50 to 3 when stretched 50% in the MD direction
00kgf / cm ^2, 1 and extends 50% (4) MD Direction
The residual stress after one minute is 25 to 160 kgf / cm ² .

When the tensile modulus in the MD direction of the olefin-based resin film becomes too small, it becomes too soft and the strength is reduced, so that the heat-insulating foam for air conditioner piping is loosened or rattled. Is insufficient, and the ability to follow irregularities is reduced, so that 150 to 1500 kgf /
limitation cm ^2, preferably 400~1200kgf
/ Cm ² .

When the olefin-based resin film has a yield point, the tape colored above the yield point is whitened so that the appearance is reduced, or the tensile strength is reduced above the yield point, and the tape is spirally wound around a copper tube. In such a case, it is not possible to apply a necessary stress and it is not possible to bind beautifully. Therefore, it is necessary to have no yield point, and it is preferable that the stress gradually increases with elongation.

When the olefin resin film is stretched,
The smaller the stress, the smaller the stress required for spiral winding
The appearance of the tied material is reduced
Insufficient binding power and heat insulation when wound
Since the foam is crushed and the heat insulating effect is reduced, 5 in the MD direction.
The stress at 0% elongation is 50-300 kgf / cm ^Two
, Preferably 80 to 150 kgf / cm^Twoso
is there.

The residual stress when the olefin-based resin film is stretched in the MD direction is such that when the residual stress is small, the material to be tied becomes loose or loose, and when the residual stress is large, the heat insulating foam is crushed when wound. In some cases, the heat insulation effect may be reduced, or the end of the tape in the width direction may be curled, thereby deteriorating the appearance. Therefore, the residual stress after 50 minutes in the MD direction is limited to 25 to 160 kgf / cm ² after 1 minute. Is done.

[0016] The tensile modulus is JIS K 7127.
According to the standard, a film having a thickness of 150 μm and a width of 10 mm is gripped in the MD direction at a distance between gripping tools of 40 mm.
It was measured by a tensile test at a speed of 00 mm / min. The stress when the film is stretched by 50% in the MD direction is the stress when the film is stretched by 1.5 times in the above measurement. The stress after stopping the stretching and holding the film as it is for 1 minute is MD stress. Is the residual stress one minute after elongating 50% in the direction.
In the present invention, extending 50% in the MD direction means extending 1.5 times in the MD direction.

As the olefin resin used in the present invention, any olefin resin may be used as long as it has the above-mentioned physical properties, but polypropylene having a weight average molecular weight (Mw) of 80,000 to 600,000 is preferred. It is a system resin.
When the weight average molecular weight (Mw) is less than 80,000, sufficient tape strength cannot be obtained, and when it exceeds 600,000, flexibility is insufficient.
More preferably, the weight average molecular weight is 170,000 to 440,000.
The weight average molecular weight (Mw) is, for example, WATERS
It is measured by a high-temperature GPC “150CV” manufactured by the company.

The resin elution amount of the above-mentioned polypropylene resin measured by the cross fractionation method is 40 to 70% by weight of the total amount of the polypropylene resin at 0 ° C, and 10 to 30% of the total amount of the polypropylene resin above 0 ° C and 70 ° C or less. It is preferable that the amount is more than 70% by weight and 20 to 40% by weight of the total amount of the polypropylene resin.

If the amount of resin eluted at 0 ° C. is less than 40% by weight of the total amount of the polypropylene resin, the tensile elasticity of the tape becomes too large and the ability to follow the pipe insulation material is insufficient. If the amount is more than 10% by weight, the strength of the tape is reduced, and the binding power to the pipe insulation is insufficient. More preferably, it is 45 to 60% by weight.

The resin elution amount at a temperature exceeding 0 ° C. and 70 ° C. or less is:
50% if less than 10% by weight of total polypropylene resin
The residual stress of the tape after elongation becomes too large, and if it exceeds 30% by weight, the stress at 50% elongation of the tape becomes insufficient.
More preferably, it is 15 to 25% by weight.

When the resin elution amount at more than 70 ° C. is less than 20% by weight of the total amount of the polypropylene resin, the strength of the tape is insufficient. Lack of followability. More preferably, it is 25 to 40% by weight.

The elution amount by the cross fractionation method referred to in the present invention is a value measured by the following method. First, a polypropylene-based resin is dissolved in o-dichlorobenzene at 140 ° C or a temperature at which the resin is completely dissolved, and then cooled at a constant rate. A thin polymer layer is crystallized on the surface of an inert carrier prepared in advance. It is produced in the order of high molecular weight and high molecular weight. Next, the temperature of the formed polymer layer is continuously or stepwise increased, the concentrations of the eluted components are sequentially detected, and the composition distribution (crystallinity distribution) is measured. This is referred to as temperature rise elution fractionation. At the same time, the eluted components are analyzed by high-temperature GPC to measure the molecular weight and the molecular weight distribution.

In the present invention, the temperature rise elution fractionation (TREF = Temperature Rising E)
and a high-temperature GPC (SEC = Size Exclusion)
The measurement was carried out using a cross-separation chromatograph (trade name “CFC-T150A”, manufactured by Mitsubishi Chemical Corporation) equipped with both Chromatograph portions as a system.

The above-mentioned polypropylene resin is preferably obtained by polymerizing ethylene and propylene monomers in the presence of polypropylene, that is, by a reactor blending method. No.-205439, and are marketed under the trade names of "Cataroy" by Montell and "PER" by Tokuyama.

The above-mentioned olefin-based resin includes low-density polyethylenes other than those described above as long as the effects of the present invention are not impaired.
Olefin resins such as linear low-density polyethylene, high-density polyethylene, ethylene-vinyl acetate copolymer, ethylene-α-olefin copolymer, polypropylene, and polybutene may be added. Further, additives such as antioxidants, ultraviolet absorbers, light stabilizers, slip agents, antiblocking agents, etc .; inorganic fillers such as calcium carbonate, talc, mica, etc. may be added, and colored with pigments, dyes, etc. May be done.

As a method for producing a tape comprising the above-mentioned olefin resin, any conventionally known method for producing a film such as a T-die method, an air-cooled or water-cooled inflation method, or a calender method can be applied. The method is preferable because the thickness accuracy is good. In order to improve molding efficiency and workability, other olefin-based resins may be laminated on one or both sides of the tape as long as the effects of the present invention are not impaired, and printing is performed on one or both sides of the tape after molding. May be done.

Although the above-mentioned tape can provide a sufficient effect as a tape for air conditioner piping even if it is not stretched, in order to further enhance the effect of the present invention, the stretching temperature is 60 to 150.
It is preferred that the film be stretched at least in one of the MD direction and the TD direction at a temperature of 1.1 ° C. and a draw ratio of 1.1 to 5 times.
The stretching in the MD direction is performed to increase the stress at the time of stretching,
Stretching in the TD direction is performed in order to enhance hand-cutting properties.

If the stretching temperature is less than 60 ° C., the stress of the stretched tape is too high to perform sufficient stretching.
If the temperature exceeds 50 ° C., stress relaxation after elongation becomes insufficient in the case of stretching in the MD direction, and hand-cutting properties become insufficient in the case of stretching in the TD direction. Preferably a stretching temperature of 75 to 120
° C.

If the stretching ratio is less than 1.1 times, the stretching effect is not sufficiently exhibited, and if it exceeds 5 times, the tape becomes too hard and the flexibility is insufficient. Preferably stretch ratio 1.5
~ 2.5 times.

The stretching method is not particularly limited as long as the tape can be stretched in at least one direction. Examples thereof include tenter stretching, longitudinal uniaxial stretching, simultaneous biaxial stretching, sequential biaxial stretching, roll rolling stretching, and tube stretching. For example, a method such as color stretching is preferably used, and an annealing treatment may be performed as necessary.

The thickness of the tape may be appropriately determined depending on the application, but is generally preferably 20 to 300 μm.
More preferably, it is 100 to 170 μm. The tape width may be appropriately determined depending on the application, but is generally 10 to 10.
200 mm is preferred, and more preferably 30 to 70 mm
It is. Further, one or both sides of the tape may be embossed in order to improve the appearance of the tape or adjust the slip.

By using the above tape as a substrate and forming an adhesive layer on one surface of the substrate, an adhesive tape is obtained.
As the pressure-sensitive adhesive, conventionally known pressure-sensitive adhesives such as acrylic, rubber, urethane, and silicone are used.
As the method for forming the pressure-sensitive adhesive layer, any conventionally known method can be adopted, for example, a method in which a pressure-sensitive adhesive solution or an emulsion is applied to one surface of a substrate and dried; And a method of co-extruding a substrate and a melt-type pressure-sensitive adhesive. The thickness of the pressure-sensitive adhesive layer is appropriately determined depending on the application, but is generally preferably 10 to 50 μm.

A release agent layer may be provided on the non-adhesive layer side of the pressure-sensitive adhesive tape. In order to enhance the anchor effect (adhesion) between the substrate and the pressure-sensitive adhesive layer and the release agent layer, May be subjected to a corona treatment.

[0034]

In order to bind an air conditioner pipe or the like with the tape or the adhesive tape of the present invention, one end of the tape or the adhesive tape is fixed to an object to be bound, spirally wound while being pulled, and then the other end is fixed. Unite by This tape is flexible and easy to stretch and has no yield point, so it follows the unevenness of the material to be tied well, so the appearance of the tied material is excellent, and the stress increases with elongation, so the material to be tied loose or rattle Since the foam has no residual stress and has an appropriate residual stress, the foam is not crushed when, for example, the heat-insulating foam is bound, so that the heat insulating performance is not reduced.

[0035]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described specifically with reference to examples, but the present invention is not limited to the examples.

(Example 1) Weight average molecular weight (Mw) 44
The resin elution amount measured by the cross fractionation method is 0 ° C
55% by weight, 18% by weight above 70 ° C and below 70 ° C, 70 ° C
100 parts by weight of a polypropylene-based resin (manufactured by Montell, trade name "Cataroy KS-353P") of 27% by weight, high-density polyethylene (MFR = 2.0 g / 10)
Min, density of 0.94g / cm ³⁾ 10 parts by weight, and, to obtain an olefinic resin film having a thickness of 120μm the resin composition consisting of titanium oxide 1 part by weight is extruded by T-die. The MFR of high-density polyethylene is JIS K7
The measurement was performed at a temperature of 190 ° C. and a load of 2.16 kgf in accordance with No.

The tensile modulus of the obtained film, the stress when the film was stretched by 50% in the MD direction, and the residual stress after 1 minute after being stretched by 50% in the MD direction were measured in accordance with JIS K 7127. The presence or absence of points was checked, and the results are shown in Table 1.

The above film was placed in a paper tube having an outer diameter of 37 mm for 20 minutes.
After winding with a length of m, the tape was slit to a width of 50 mm to obtain a tape. This tape is fixed to each of the objects to be tied having a length of 5 m described below in (1) to (4) with an adhesive tape at the start end of the tape, and then wound and tied while being pulled in a spiral manner to wrap the bandage. Then, the end of the winding was fixed with an adhesive tape to obtain a bundle. (1) an outer diameter of 28 mm through which a 9 mm outer diameter copper tube is passed;
8 mm-thick foamed polyethylene tube (2) 28 mm outer diameter with a 6 mm outer diameter copper tube inserted inside,
8mm thick foamed polyethylene tube (3) Flat cable with a long diameter of 14mm and a short diameter of 6mm in which three cores of copper wire of 2mm in diameter are coated with soft resin (4) A plastic drain hose of 20mm in outer diameter and 1mm in thickness

The appearance and binding property of each of the above-mentioned binding bodies were evaluated according to the following criteria, and the results are shown in Table 1. (A) Appearance (following irregularities and generation of wrinkles) Due to insufficient flexibility and elongation of the tape, wrinkles of 5 mm or more in length are generated in the TD direction of the tape at the bent portion of the pipe. The appearance was marked with x if the appearance was significantly impaired, the wrinkles with a length of less than 5 mm less than 5 in a winding length of 4 m, but practically no hindrance were indicated by ○, and those without any wrinkles were indicated with ◎. did.

(B) Appearance (whitening) The tape yielded due to tension and impaired appearance due to whitening was indicated by x, and the tape yielded without yielding and not whitened was indicated by ○.

(C) Appearance (insufficient concealment due to elongation) As a result of stretching of the tape due to tension, the thickness of the tape becomes thinner. Those which did not exist are indicated by ○.

(D) Bundling property (rattle, looseness) When the part of the material to be bound which is not wound with the tape was shaken by hand, the tape was cut off, and the tape was not cut but was partially cut.伸 び indicates that there was elongation or loosening, but there was no practical problem, and ◎ indicates that no rattling or loosening occurred.

Example 2 The olefin-based resin film obtained in Example 1 was roll-drawn at a draw ratio of 1.8 times using a heating furnace having a furnace length of 5 m and a furnace temperature of 110 ° C. to obtain a stretched film. Was. The same measurement as in Example 1 was performed for this stretched film, and the results are shown in Table 1. Furthermore, after producing a tape in the same manner as in Example 1 using this stretched film, the same appearance and binding property as in Example 1 were evaluated.
The results are shown in Table 1.

Comparative Example 1 Vinyl chloride resin (degree of polymerization: 10
00) A resin composition comprising 100 parts by weight and 48 parts by weight of dioctyl phthalate is calender-molded to a thickness of 120 parts.
A μm soft vinyl chloride film was obtained. The same measurement as in Example 1 was performed for this soft vinyl chloride film, and the results are shown in Table 1. Further, a tape was produced using this soft vinyl chloride film in the same manner as in Example 1,
The same appearance and cohesiveness as in Example 1 were evaluated, and the results are shown in Table 1.

Comparative Example 2 Linear low-density polyethylene (trade name "UltraZEX 2020" manufactured by Mitsui Chemicals, Inc.)
L ", MFR = 1.8 g / 10 min, density 0.920 g /
cm ³ ) was extruded with a T-die to obtain an olefin-based resin film having a thickness of 120 μm. The same measurement as in Example 1 was performed for this olefin-based resin film, and the results are shown in Table 1. Furthermore, after producing a tape in the same manner as in Example 1 using this olefin-based resin film, the same appearance and binding property as in Example 1 were evaluated.
It was shown to.

[0046]

[Table 1]

Example 3 One surface of the olefin resin film base material obtained in Example 1 was subjected to a 40 dyn corona discharge treatment, and an acrylic pressure-sensitive adhesive (trade name "SK Dyne" manufactured by Soken Chemical Co., Ltd.) was applied to the treated surface. 1502C ") A pressure-sensitive adhesive composition comprising 100 parts by weight and 5 parts by weight of an isocyanate-based crosslinking agent is applied, dried at 120 ° C. for 5 minutes, and a pressure-sensitive adhesive layer having a thickness of 30 μm is laminated. , And slit to a width of 50 mm to obtain an adhesive tape. This adhesive tape was evaluated for the same appearance and binding property as in Example 1, and the results are shown in Table 2.

Example 4 An adhesive tape was obtained in the same manner as in Example 3 except that the stretched film obtained in Example 2 was used as a substrate. This adhesive tape was evaluated for the same appearance and binding property as in Example 1, and the results are shown in Table 2.

(Comparative Example 3) A rubber-based pressure-sensitive adhesive was applied to one surface of the soft vinyl chloride film base material obtained in Comparative Example 1, and dried at 130 ° C. for 5 minutes to laminate a pressure-sensitive adhesive layer having a thickness of 30 μm. The obtained adhesive tape was obtained. This adhesive tape was evaluated for the same appearance and binding property as in Example 1, and the results are shown in Table 2.

Comparative Example 4 An adhesive tape was obtained in the same manner as in Example 3 except that the olefin resin film obtained in Comparative Example 2 was used as a substrate. This adhesive tape was evaluated for the same appearance and binding property as in Example 1, and the results are shown in Table 2.

[0051]

[Table 2]

[0052]

The tape or pressure-sensitive adhesive tape according to the present invention has the structure as described above. One end of the tape or pressure-sensitive adhesive tape is adhered to the material to be tied, and when the tape or the tape is tied while being pulled, the tape or pressure-sensitive adhesive tape is stretched to have a high stress. In the state, it can be tied to the object to be tied. After the tying, the tape or the adhesive tape can relieve the stress, but has a high residual stress, so that it can be tied tightly. It can be beautifully united.

Further, since the tape or pressure-sensitive adhesive tape of the present invention uses an olefin resin as a base material, there is no concern about environmental pollution due to harmful gases even when incinerated. Can be suitably used for binding applications.

Claims (4)

[Claims] 1. A tape comprising an olefin resin film having the following physical properties. (1) The tensile modulus in the MD direction is 150 to 1500 kgf /
cm ² , (2) no yield point when stretched in the MD direction, (3) stress of 50 to 3 when stretched 50% in the MD direction
00kgf / cm ^2, 1 and extends 50% (4) MD Direction
The residual stress after one minute is 25 to 160 kgf / cm ² . 2. An olefin resin having a weight average molecular weight of 8
10,000 to 600,000 polypropylene resin, the resin elution amount of which is measured by the cross fractionation method is 40 to 70% by weight of the total polypropylene resin amount at 0 ° C, and the total polypropylene resin amount is more than 0 ° C and 70 ° C or less. The tape according to claim 1, wherein the content is 10 to 30% by weight, and 20 to 40% by weight at a temperature exceeding 70C. 3. The tape according to claim 1, wherein the tape is stretched in at least one of the MD and TD directions and has a stretching ratio of 1.1 to 5 times. 4. An adhesive tape comprising a pressure-sensitive adhesive layer laminated on one surface of the tape according to claim 1.