JP2002105411A - Adhesive tape - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the decrease in tackiness with time when a halogen-free flame-retardant resin composition made from a base polymer comprising a polyolefin polymer is used for the base material in an adhesive tape consisting of a base material and an adhesive layer formed on the surface of the base material. SOLUTION: The base material 1 used comprises a flame-retardant resin composition made by blending 100 pts. base polymer comprising a polyolefin polymer with 0.5-50 pts. calcium carbonate or talc, and having a specific gravity of at most 1.14, an oxygen index of at least 24 and a heavy metal content of at most 0.1 wt.%. The base material 1 has a surface with an average roughness of 0.3-1 μm or a ten-point average roughness of 3-10 μm.

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 wiring work of electric wires and cables and the like, which does not generate harmful gas during combustion and has good adhesiveness.

[0002]

2. Description of the Related Art Conventionally, this kind of adhesive tape has a thickness of 0.1 to 0.3 mm made of soft polyvinyl chloride.
A tape-shaped base material having a width of 15 to 30 mm and having an adhesive layer made of a butyl rubber-based adhesive or the like formed on one surface (hereinafter referred to as a PVC adhesive tape) is widely used.

[0003] Meanwhile, there is a movement to stop using vinyl chloride-based plastic, which is a source of dioxin, since environmental issues are now considered important. For this reason, vinyl chloride is also being used for coating materials such as electric wires and cables, and vinyl chloride is being demanded for adhesive tapes used for connection of electric wires and cables.

[0004] In order to satisfy this demand, a resin composition forming a base material of an adhesive tape, a mixture of a polyolefin polymer and a flame retardant of a metal hydroxide such as magnesium hydroxide, is used. A proposal has been made to impart the same level of flame retardancy so that dioxin and halogen-containing gas are not generated during combustion.

However, such a pressure-sensitive adhesive tape made of a polyolefin polymer has a problem in that the adhesive strength is inferior to that of a pressure-sensitive adhesive tape made of PVC. In particular, the adhesive force decreases significantly with time, for example, self-back surface adhesive force; a state in which an adhesive layer of another adhesive tape is laminated on the surface of the base material of the adhesive tape and two adhesive tapes are adhered to each other, in other words, the adhesive tape May be reduced to about 1/5 of the initial value after two weeks.

[0006]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to reduce the adhesive strength of a pressure-sensitive adhesive tape having a substrate made of a flame-retardant resin composition containing a polyolefin-based polymer as a base polymer, and particularly to reduce the adhesive strength over time. Is to prevent it.

[0007]

An object of the present invention is to provide a polyolefin-based polymer as a base polymer, and blending 0.5 to 50 parts of calcium carbonate or talc with 100 parts (parts by weight, hereinafter the same) of the base polymer. And a specific gravity of 1.14 or less, an oxygen index of 24 or more, and a heavy metal content of 0.1.
The problem can be solved by using a substrate made of a flame-retardant resin composition containing no more than 1% by weight of halogen. Also,
It is preferable that the average roughness of the substrate surface is 0.3 to 1 μm or the ten-point average roughness is 3 to 10 μm.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
FIG. 1 shows an example of the pressure-sensitive adhesive tape of the present invention. In the figure, reference numeral 1 denotes a base material, and 2 denotes a pressure-sensitive adhesive layer. The base material 1 is obtained by extrusion molding, inflation molding, and calender molding of the flame-retardant resin composition, and has a width of 15 to 30 mm and a thickness of 0.1.
~ 0.3mm tape-like material and base material 1
The average roughness of the surface is 0.3 to 1 μm, or the ten-point average roughness of the surface of the substrate 1 is 3 to 10 μm. The surface roughness of the substrate surface in the present invention refers to the surface roughness that can be controlled according to JIS B0601.

The flame-retardant resin composition uses a polyolefin-based polymer as a base polymer, and blends 0.5 to 50 parts of calcium carbonate or talc with respect to 100 parts of the base polymer. A composition not containing a halogen element such as chlorine, fluorine, or bromine having an oxygen index of 24 or more and a heavy metal content of 0.1% by weight or less is used.

Specific examples of polyolefin polymers include polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, ethylene-butene-
One or more blended polymers such as one copolymer are used. Among them, ethylene-ethyl acrylate copolymer (50 to 70% by weight) and ethylene-vinyl acetate copolymer (30 to 50% by weight) A polymer blended with the above is preferable because the feeling of hand-cutting of the obtained pressure-sensitive adhesive tape is improved, and a feeling of use equivalent to that of a conventional PVC pressure-sensitive adhesive tape is obtained.

In order to obtain an oxygen index of 24 or more,
A non-halogen flame retardant is added. Non-halogen flame retardants include magnesium hydroxide, aluminum hydroxide,
Flame retardance of metal hydroxides such as calcium hydroxide and silane-treated metal hydroxides, surface-treated with a silane coupling agent to enhance affinity for base polymers, gum-like silicone, silicone resin powder, etc. Auxiliaries are used.

The amount of the metal hydroxide to be added is 40 to 50 parts based on 100 parts (parts by weight, hereinafter the same) of the base polymer. If the amount is less than 40 parts, the improvement in flame retardancy is insufficient, and the amount exceeds 50 parts. And the specific gravity exceeds 1.14, and the mechanical strength decreases.
The compounding amount of the flame retardant aid is 5 to 10 parts with respect to 100 parts of the base polymer. When the amount is less than 5 parts, the effect of the addition is not exhibited, and when the amount exceeds 10 parts, the specific gravity increases, which is not preferable.

When the oxygen index of the flame-retardant resin composition is less than 24, the flame retardancy is inferior to that of the pressure-sensitive adhesive tape made of PVC and cannot be used as a substitute. In addition, by setting the specific gravity to 1.14 or less, it is possible to perform separation based on the specific gravity from a conventional PVC product. Further, by setting the heavy metal content to 0.1% by weight or less, cadmium, lead, and the like, which are detrimental to the combustion ash, are reduced to the regulated values or less, thereby facilitating disposal.

The flame-retardant resin composition further comprises a base material 1
Calcium carbonate or talc is blended in order to impart a desired roughness to the surface of the rubber and prevent the adhesive strength from decreasing over time. These calcium carbonate or talc may be used alone or in a mixture at an arbitrary ratio. The particle size of the calcium carbonate or talc is also related to the surface roughness of the substrate 1, but is preferably from 0.1 to 5 μm, particularly preferably from 1 to 2 μm. It has a high affinity with the base polymer and is preferred.

The amount of the calcium carbonate or talc is 0.5 to 50 based on 100 parts of the base polymer.
Parts, preferably 1 to 10 parts. If the amount is less than 0.5 part, the effect of preventing a decrease in the adhesive strength cannot be obtained, and the average roughness of the substrate 1 is less than 0.3 μm or the ten-point average roughness is less than 3 μm. When the amount of these components exceeds 50 parts, the base material 1
Becomes harder and the mechanical properties are reduced, and the average roughness of the substrate 1 exceeds 3 μm, or the ten-point average roughness exceeds 10 μm.

The composition may optionally further contain an antioxidant, a coloring agent, an inorganic filler, an ultraviolet absorber and the like, if necessary. Further, the flame-retardant resin composition desirably has a volume resistance value of 10 ¹³ Ω · cm or more, and a pressure-sensitive adhesive tape obtained thereby has a sufficient electric insulating property, and is similar to a pressure-sensitive adhesive tape made of PVC. It can also be used for electrical insulation.

The pressure-sensitive adhesive layer 2 is not particularly limited, and is a well-known pressure-sensitive adhesive, for example, an SBR pressure-sensitive adhesive, an acrylic pressure-sensitive adhesive, a natural rubber-based pressure-sensitive adhesive, an isoprene rubber-based pressure-sensitive adhesive, an isobutylene rubber-based pressure-sensitive adhesive. An adhesive or the like is appropriately selected and used depending on the use or the like.

As the SBR-based pressure-sensitive adhesive, styrene-butadiene rubber is used as a main component. Softeners, fillers such as carbon black, silicates, calcium carbonate, clay, toluene,
Solvents such as hexane and unleaded gasoline, and those containing an antioxidant and the like are used. When an SBR adhesive is used, the thickness of the adhesive layer 2 is 0.02 to 0.04.
mm. If it is less than 0.02 mm, the adhesive strength is insufficient,
When the thickness exceeds 0.04 mm, the adhesive strength becomes excessive and the workability is reduced.

The acrylic pressure-sensitive adhesive has a glass transition temperature obtained by copolymerizing two or more kinds of various acrylates.
The main component is an acrylic copolymer of 20 ° C or less,
If necessary, the above-mentioned tackifiers, softeners, fillers, solvents, antioxidants and the like are appropriately blended. When an acrylic pressure-sensitive adhesive is used, the thickness of the pressure-sensitive adhesive layer 2 is 0.005 to 0.03 mm. 0.005
If it is less than 0.03 mm, the adhesive strength is insufficient, and if it exceeds 0.03 mm, the adhesive strength becomes excessive and the workability is reduced.

Acrylic pressure-sensitive adhesives generally have a higher adhesive strength than butyl rubber-based pressure-sensitive adhesives, SBR-based pressure-sensitive adhesives, etc., so that a sufficiently strong pressure-sensitive adhesive force can be obtained even if the thickness of the pressure-sensitive adhesive layer 2 is small. If the thickness of the pressure-sensitive adhesive layer 2 is small, it is possible to increase the thickness of the substrate 1 if the thickness of the entire pressure-sensitive adhesive tape is kept constant, and it is possible to increase the mechanical strength of the pressure-sensitive adhesive tape of the substrate 1. Become.

As the natural rubber-based pressure-sensitive adhesive, natural rubber is used as a main component, and the above-mentioned tackifier, softener, filler,
What appropriately mixed a solvent, an antioxidant, and the like is used. When a natural rubber-based pressure-sensitive adhesive is used, the thickness of the pressure-sensitive adhesive layer 2 is 0.005 to 0.03 mm. 0.0
If it is less than 05 mm, the adhesive strength is insufficient, and if it exceeds 0.03 mm, the adhesive strength becomes excessive and the workability is reduced.

As the isoprene rubber-based pressure-sensitive adhesive, one containing isoprene rubber as a main component, and the above-mentioned tackifier, softener, filler, solvent, antioxidant and the like appropriately blended is used. When an isoprene rubber-based adhesive is used, the thickness of the adhesive layer 2 is 0.005 to 0.03 mm.
It is said. If it is less than 0.005 mm, the adhesive strength is insufficient,
If it exceeds 0.03 mm, the adhesive strength will be excessive and workability will be reduced.

As the isobutylene rubber-based pressure-sensitive adhesive, isobutylene rubber is used as a main component, and the above-mentioned tackifier,
Those appropriately mixed with a softening agent, a filler, a solvent, an antioxidant and the like are used. When an isobutylene rubber-based adhesive is used, the thickness of the adhesive layer 2 is 0.005 to 0.0
3 mm. If it is less than 0.005 mm, the adhesive strength is insufficient, and if it exceeds 0.03 mm, the adhesive strength becomes excessive and the workability is reduced.

The method for producing such a pressure-sensitive adhesive tape is not particularly limited, but the above-described flame-retardant resin composition is kneaded, and is extruded, blow-molded, calendered, or the like to a thickness of 0.1 to 0.1 mm. There is a method in which a 3 mm wide film is manufactured, and the above-mentioned various adhesives are applied to one side of the film to a predetermined thickness by a coating device, and then cut into a width of 10 to 30 mm by a slitter and wound. In this case, by performing a corona treatment, a primer treatment, and the like on the surface of the substrate 1 on which the adhesive is applied,
It is also possible to adopt a method of improving the adhesive strength between the pressure-sensitive adhesive layer 2 and the substrate 1.

In such an adhesive tape, the base material 1 is a resin composition having a polyolefin-based polymer as a base polymer, an oxygen index of 24 or more, a specific gravity of 1.14 or less, and a heavy metal content of 0.1% by weight or less. Since it is made of a material, it exhibits flame retardancy equal to or higher than that of an adhesive tape made of PVC, can be separated from specific polyvinyl chloride products with specific gravity, does not generate harmful substances during combustion, and emits no smoke. Also PVC
Significantly less than adhesive tape.

The flame retardant resin composition constituting the base material 1 contains 0.5 to 50 parts of calcium carbonate or talc with respect to 100 parts of the base polymer. When the roughness is 0.3 to 1 μm or the ten-point average roughness is 3 to 10 μm, an appropriate surface roughness is given to the substrate 1, and as is clear from the specific examples described below, The lowering is prevented, and as a result, the adhesive strength is increased, and the adhesiveness to electric wires, cables, and the like is improved, and workability is improved.

The following is a specific example. A flame-retardant resin composition having the compounding composition shown in Tables 1 and 2 was prepared, and this was blown-molded to obtain a 0.2-mm-thick base film. The average roughness and the ten-point average roughness of the surface of this film were measured with a stylus type surface roughness measuring instrument specified in JIS B 0651. One side of this film was coated with an acrylic pressure-sensitive adhesive to a thickness of 0.03 mm and cut with a slitter to form a pressure-sensitive adhesive tape having a width of 20 mm.

In Tables 1 and 2, resin A was an ethylene-ethyl acrylate copolymer, resin B was an ethylene-vinyl acetate copolymer, and an antioxidant was a phenolic antioxidant. Was. A calcium carbonate having an average particle size of 1.5 μm and a talc having an average particle size of 1 μm were used. With respect to the adhesive force of this adhesive tape, the change with time of the adhesive force to stainless steel and the change with time of the self-back surface adhesive force were measured. The results are shown in Tables 1 and 2.

[0029]

[Table 1]

[0030]

[Table 2]

From the results shown in Tables 1 and 2, from 0.5 to 50 parts of calcium carbonate or talc were added, and the average roughness of the substrate surface was adjusted to 0.3 to 1 μm or the ten-point average roughness was adjusted to 3 points. It can be seen that by setting the thickness to 10 μm, the time-dependent decrease in the adhesive strength is extremely effectively prevented.

[0032]

As described above, according to the pressure-sensitive adhesive tape of the present invention, it has a flame-retardant performance equal to or higher than that of a conventional PVC pressure-sensitive adhesive tape, and generates harmful substances such as dioxin and halogen-containing gas during combustion. And the amount of smoke generated is small. Further, specific gravity separation from conventional polyvinyl chloride products becomes possible, and waste disposal becomes easy. Further, there is obtained such an effect that the adhesive force does not decrease with time, has an appropriate adhesive force in actual use, and improves workability.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of an adhesive tape of the present invention.

[Explanation of symbols]

 1. Base material 2. Adhesive layer

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4J002 BB021 BB061 BB071 BB111 BB151 BF031 BG021 DE046 DE236 DJ046 FD130 FD340 GJ00 4J004 AA04 AA05 AA10 AB01 CA03 CA04 CC02 CD08 DB01 EA01 FA05

Claims (4)

[Claims] 1. A polyolefin-based polymer is used as a base polymer, and 100 parts by weight of the base polymer is
0.5-50 parts by weight of calcium carbonate is blended, and specific gravity is 1.
A pressure-sensitive adhesive tape having a pressure-sensitive adhesive layer provided on the surface of a base material comprising a flame-retardant resin composition containing no halogen and having an oxygen index of 14 or less, an oxygen index of 24 or more and a heavy metal content of 0.1% by weight or less. 2. A polyolefin-based polymer is used as a base polymer, and based on 100 parts by weight of the base polymer.
0.5 to 50 parts by weight of talc are blended, and the specific gravity is 1.14 or less, the oxygen index is 24 or more, and the heavy metal content is 0.1% by weight or less. , An adhesive tape provided with an adhesive layer. 3. The flame-retardant resin composition contains 40 to 50 parts by weight of a metal hydroxide and 5 to 10 parts by weight of a flame-retardant aid based on 100 parts by weight of a base polymer. Item 3. The pressure-sensitive adhesive tape according to Item 1 or 2. 4. An average roughness of a substrate surface is 0.3 to 1 μm,
4. The pressure-sensitive adhesive tape according to claim 1, wherein the ten-point average roughness of the substrate surface is 3 to 10 μm. 5.