JP4601040B2 - Binding tape - Google Patents

Description

  The present invention relates to a bundling tape for bundling electric wires and cables used in electric devices and automobiles. Units such as “parts” indicating the blend composition of the binding tape of the present invention are displayed on a mass basis unless otherwise specified.

  Resin composition containing a halogenated vinyl resin such as polyvinyl chloride as a bundling tape for bundling electric wires and cables of electrical equipment and automobiles because of its low production cost and excellent flame retardancy. Films made from these materials have been used. For example, when an electric wire / cable is burned for incineration disposal, corrosive hydrogen chloride gas is generated from the polyvinyl chloride resin composition. Therefore, in recent years, attempts have been made to use an olefin resin composition such as polyethylene as an insulator that does not use a halide as an insulator for electric wires and cables in places that generate high temperatures, such as an automobile wire harness. However, even when an olefin-based resin composition that is not a halide is used as an insulator for an automobile electric wire such as an automobile wire harness, when using a halide for a binding tape used for focusing or protecting an automobile electric wire or the like, during combustion, Halogen gas will be generated. Therefore, non-halogen binding tapes that do not generate harmful halogen-based gas during combustion are beginning to be used for binding tapes used for focusing and protecting such automobile wires.

As a binding tape using a film made of such a non-halogen resin composition as a raw material, the applicant of the present invention uses a composition comprising ethyl acrylate and ethylene and magnesium hydroxide as a film base. The tape characterized by having performed is disclosed (for example, patent document 1).
Japanese Patent Laid-Open No. 5-201462

However, bundling tape using films made of these non-halogen resin compositions as raw materials is, for example, easy to use and hand-cut to be used as a tape for bundling complex wires and cables in automobile engine rooms. There was a problem with sex.

An object of the present invention is to provide a bundling tape that solves the conventional drawbacks and has a good balance of flexibility, winding workability, and hand cutting properties required as a bundling tape.

That is, the present invention is a binding tape in which the film base is composed of 1 to 200 parts of a polypropylene resin and 1 to 100 parts of an inorganic filler having a particle diameter of 0.5 μm to 10 μm with respect to 100 parts of an ethylene acrylate copolymer. is there. The ethylene acrylate copolymer is a binding tape selected from an ethylene-ethyl acrylate polymer, an ethylene-methyl acrylate polymer, and an ethylene-propyl acrylate polymer.

Furthermore, it is a binding tape obtained by irradiating a film substrate with an electron beam and crosslinking. Furthermore, it is a binding tape having a back adhesive strength of 1.5 to 5.0 N / 10 mm in accordance with JIS C 2107. Further, it is a binding tape in which an adhesive layer is formed on one side of a film base material.

A bundling tape having excellent flexibility and workability and cutting ability equivalent to that of a polyvinyl chloride tape can be obtained.

In general, when a film substrate is composed of a composition in which an inorganic filler is added to a polyolefin resin, the flexibility and extensibility required for a binding tape are required from the viewpoint of followability to the adherend and winding workability. Considering this, high-density polyethylene (HDPE) having a relatively high melting point is not suitable as the polyolefin resin, and low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and very low-density polyethylene (VLDPE). It is preferable to use a polyolefin resin having a low melting point such as medium density polyethylene (MDPE), ethylene-vinyl acetate copolymer (EVA), or ethylene-ethyl acrylate copolymer (EEA). However, such a low melting point polyolefin resin is likely to be thermally deformed, and a binding tape based on a polyolefin resin as a base material cannot provide good results in terms of heat distortion resistance.

In the present invention, the reason why the polypropylene resin is blended with the ethylene acrylate copolymer is that the melting point of the polypropylene resin alone is 130 to 170 ° C., so that the processing temperature when the binding tape is produced in a high temperature and narrow temperature range is as follows. (180 to 220 ° C.) must be set, but when an ethylene acrylate copolymer resin is blended, the processing temperature range can be lowered and expanded, which makes it easier to manufacture. Moreover, it is because handling property and touch are similar to the conventional PVC binding tape as a binding tape.

Examples of the ethylene acrylate copolymer that can be used for the film substrate include an ethylene-ethyl acrylate polymer, an ethylene-methyl acrylate polymer, an ethylene-propyl acrylate polymer, and the ethylene acrylate copolymer is, Each of them may be used alone, or a plurality of them may be used in combination. Also, a modified product obtained by replacing the acrylic acid with methacrylic acid, a modified product obtained by adding or substituting a low molecule such as maleic anhydride containing a functional group such as a carboxyl group to the copolymer, if necessary, etc. Is a conventionally known one or a mixture thereof, and the type and mixing ratio of the resin can be arbitrarily selected according to various conditions such as required characteristics and cost of the film substrate.

  Examples of the polypropylene resin include polypropylene homopolymer, high crystallinity homopolymer with high crystallinity, polypropylene random copolymer which is a propylene-ethylene copolymer, polypropylene block polymer, polypropylene and CH2 = CHR (R: carbon number 2 ~ 8 aliphatic and aromatic) polymerized polypropylene block polymers, polypropylene as a hard segment, ethylene-propylene rubber (EPR), ethylene-propylene diene rubber (EPDM), acrylonitrile butadiene rubber (NBR), natural rubber (NR) There are polypropylene polymers (TPO) that are polymerized in a melt kneading and reactor using, for example, a segment. Polypropylene resins may be used alone or in combination of two or more.

  The compounding quantity of a polypropylene-type resin is the range of 1-200 parts with respect to 100 parts of ethylene acrylate ester copolymers. When the polypropylene resin is less than 1 part, the base material is soft and easily stretched, and workability and hand cutting performance are lowered. On the other hand, when the amount of the polypropylene resin exceeds 200 parts, the processing temperature of the base material increases, the workability is lost, the base material becomes rigid, the pinhole resistance decreases, and the flexibility is lost.

The reason for blending inorganic fillers is to improve the hand cutting property of the film base material, while increasing the heat conduction during the molding process to increase the cooling effect of the film base material and to suppress the distortion generated in the film base material. Because. The particle diameter of the inorganic filler is in the range of 0.5 μm to 10 μm. When the particle diameter is less than 0.5 μm, workability and hand cutting properties are deteriorated. On the other hand, when the particle diameter exceeds 10 μm, the tensile strength and breaking elongation of the film base material are lowered, and the flexibility is lowered and pinholes are generated. The particle diameter is an average particle diameter measured by a laser diffraction method.

As the inorganic filler, for example, aluminum hydroxide, magnesium hydroxide, zirconium hydroxide, calcium hydroxide, potassium hydroxide, Barium, ammonium polyphosphate, polyphosphoric acid amide, oxide Jirikoniumu, magnesium oxide, zinc oxide, titanium oxide, molybdenum, hydrotalcite, snake tight, zinc borate, zinc borate anhydride, metaboric acid zinc, barium metaborate, antimony oxide, antimony trioxide, antimony pentoxide, red phosphorus, talc, alumina, silica, boehmite , Bentonite, sodium silicate, calcium silicate, calcium sulfate, calcium carbonate, magnesium carbonate and the like. You may use these individually or in combination of multiple types.

The compounding quantity of an inorganic filler is the range of 1-100 parts with respect to 100 parts of ethylene acrylate ester copolymers. When the inorganic filler is less than 1 part, the flame retardancy is not improved, and workability and hand cutting properties are also deteriorated. On the other hand, when the amount of the inorganic filler exceeds 100 parts, the tensile strength and the elongation at break are reduced, and the flexibility and the pinhole are generated. Furthermore, whitening of the cut surface of the tape cannot be suppressed, resulting in poor appearance.

When an inorganic filler is blended as a non-halogen flame retardant, the char (carbonized layer) can be formed and the flame retardancy of the film substrate can be improved.

  The shape of the binding tape is temperature dependent. For example, when the binding tape is placed at a high temperature of 120 ° C. or higher, the film base material of the binding tape is deformed or contracted. However, this temperature dependence can be reduced by irradiating the film substrate with an electron beam for crosslinking. In addition, the irradiation amount of the electron beam at this time has a good range of 10-30 Mrad (mega rad). The range of 15 to 25 Mrad is preferable. If the irradiation amount is less than 10 Mrad, the temperature dependency is not improved. On the other hand, when the irradiation amount exceeds 30 Mrad, the film base material is deteriorated by the electron beam, and a problem occurs in workability in post-processing.

A cross-linking agent for promoting electron beam cross-linking may be added. Specific examples of the crosslinking agent include low molecular weight compounds and oligomers having at least two carbon-carbon double bonds in the molecule, such as acrylate compounds, urethane acrylate oligomers, and epoxy acrylate oligomers.

In addition to inorganic flame retardants, organic flame retardants, colorants, antioxidants, ultraviolet absorbers, lubricants, stabilizers, and other additives as long as they do not interfere with the effects of the present invention. Can be blended.

  An adhesive layer may be formed on one side of the film substrate. As a pressure-sensitive adhesive for constituting the pressure-sensitive adhesive layer, a commonly used pressure-sensitive adhesive can be used as appropriate, and for example, a rubber-based pressure-sensitive adhesive or an acrylic pressure-sensitive adhesive can be used. Moreover, in order to make these adhesives have desirable performance, tackifiers, anti-aging agents, curing agents, and the like can be blended.

As the base polymer of the rubber-based adhesive, natural rubber, recycled rubber, silicone rubber, isoprene rubber, styrene butadiene rubber, polyisoprene, NBR, styrene-isoprene copolymer, styrene-isoprene-butadiene copolymer and the like are preferable.

  A crosslinking agent, a softening agent, a filler, a flame retardant, etc. can be added to a rubber-type adhesive as needed. Specific examples include isocyanate crosslinking agents as crosslinking agents, liquid rubber as softening agents, calcium carbonate as fillers, and inorganic flame retardants such as magnesium hydroxide and red phosphorus as flame retardants.

Examples of the acrylic pressure-sensitive adhesive include a homopolymer of (meth) acrylic acid ester or a copolymer with a copolymerizable monomer. (Meth) acrylic acid ester or copolymerizable monomer includes (meth) acrylic acid alkyl ester (for example, methyl ester, ethyl ester, butyl ester, 2-ethylhexyl ester, octyl ester, etc.), (meth) acrylic acid glycidyl ester , (Meth) acrylic acid, itaconic acid, maleic anhydride, (meth) acrylic acid amide, (meth) acrylic acid N-hydroxyamide, (meth) acrylic acid alkylaminoalkyl ester (for example, dimethylaminoethyl methacrylate, t- Butylaminoethyl methacrylate), vinyl acetate, styrene, acrylonitrile and the like. Of these, as the main monomer, an alkyl acrylate ester whose homopolymer (homopolymer) usually has a glass transition temperature of −50 ° C. or lower is preferred.

The tackifying resin agent can be selected in consideration of the softening point, compatibility with each component, and the like. Examples include terpene resins, rosin resins, hydrogenated rosin resins, coumarone / indene resins, styrene resins, aliphatic and alicyclic petroleum resins, terpene-phenol resins, xylene resins, and other aliphatic carbonizations. Examples thereof include hydrogen resins and aromatic hydrocarbon resins. The softening point of the tackifying resin is preferably 65 to 130 ° C, and moreover, an alicyclic saturated hydrocarbon resin of a petroleum resin having a softening point of 65 to 130 ° C, a polyterpene resin having a softening point of 80 to 130 ° C, and a softening point of 80 to 130. More preferred is a glycerin ester of hydrogenated rosin at 0 ° C. These can be used either alone or in combination.

  The anti-aging agent is used to improve the rubber-based pressure-sensitive adhesive because it has an unsaturated double bond in the rubber molecule and is likely to deteriorate in the presence of oxygen or light.

  Examples of the anti-aging agent include phenolic anti-aging agents, amine-based anti-aging agents, benzimidazole-based anti-aging agents, dithiocarbamate-based anti-aging agents, phosphorus-based anti-aging agents and the like alone or as a mixture. it can.

Examples of the curing agent for the acrylic pressure-sensitive adhesive include isocyanate-based, epoxy-based, and amine-based ones, and may be a mixture of these alone or a mixture thereof.

  Specific examples of the isocyanate curing agent include polyvalent isocyanate compounds such as 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylene diisocyanate, and diphenylmethane. -4,4'-diisocyanate, diphenylmethane-2,4'-diisocyanate, 3-methyldiphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, dicyclohexylmethane-2,4'-diisocyanate, Examples include lysine isocyanate.

  The back adhesive strength according to JIS C 2107 of the binding tape is preferably in the range of 1.5 to 5.0 N / 10 mm. When the back adhesive strength is less than 1.5 N / 10 mm, peeling occurs when the binding tape is wound around an electric wire or cable. On the other hand, if the back adhesive strength exceeds 5.0 N / 10 mm, the rewinding becomes heavy and the bundling tape is stretched when the bundling tape is wound around an electric wire / cable, resulting in poor workability at the time of winding. There is.

  The value of the back surface adhesive strength is a value calculated from a measurement value using a tensile tester, and examples of an evaluation apparatus that can perform such a measurement include trade name “AGS-500A” manufactured by Shimadzu Corporation. It is done.

  As a method for controlling the value of the back surface adhesive strength, it is possible to combine known methods such as a method for adjusting the formulation of an adhesive and the like, a method for adjusting molding conditions during molding, and the like.

As a method for adjusting the formulation of the pressure-sensitive adhesive, there is a method based on the amount of the tackifier added in the rubber-based or acrylic pressure-sensitive adhesive. For example, increasing the amount of terpene phenol as a tackifier increases the back surface adhesive strength.

As a method for adjusting the molding conditions at the time of molding the binding tape, there is a method by controlling the thickness when the adhesive is applied. For example, if the adhesive is applied thickly, the back adhesive strength increases.

There is also a method of applying a release agent to the back surface of the binding tape. For example, by applying an alkyl pendant release agent, the back adhesive strength is reduced.

The means for forming the film substrate is not particularly limited, but the above-mentioned various materials can be mixed with conventional melt-kneading and various mixing devices (single- or twin-screw extruder, roll, Banbury mixer, various kneaders, etc.). It is obtained by mixing the components so that they are uniformly dispersed, forming the mixture into a film by a calendering machine, and cutting it to a desired tape width. As the roll arrangement method in calendar molding, for example, a known method such as L-type, reverse L-type, and Z-type can be adopted, and the roll temperature is usually set in the range of 150 to 220 ° C, preferably 160 to 200 ° C. .

  The thickness of a film base material is 10-1000 micrometers normally, Preferably it is 50-400 micrometers. Since the bundling tape corresponds to the operation of winding around electric wires having various forms, generally, the workability decreases as the thickness of the film base increases.

As a method for applying the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer of the binding tape, the pressure-sensitive adhesive imparting agent and the anti-aging agent to the film substrate, a conventionally known method can be used, for example, a casting method, a roll coater method. Reverse coater method, doctor blade method, etc. can be used. Although the thickness of an adhesive layer can be suitably selected in the range which does not impair adhesiveness and handleability, 5-40 micrometers is preferable normally. More preferably, it is 10-30 micrometers. If it is 5 μm or less, the adhesive strength may be lowered, and if it exceeds 40 μm, the coating performance is deteriorated.

  Hereinafter, examples according to the present invention will be described with reference to Table 1 in comparison with comparative examples.

  In Table 1, “back adhesive strength” was measured according to JIS C 2107. In an evaluation test chamber set to a temperature of 23 ± 2 ° C. and a humidity of 50 ± 5% RH, the test piece is pressure-bonded to a SUS test plate with a binding tape to be tested, and the pressure roller is 300 mm / min. The value when the test piece was peeled off from the test plate at a speed of 300 mm / min was defined as the back adhesive strength, and the average value of n = 3 or more was described.

  In Table 1, “pinhole resistance” means that a binding tape formed to a length of 100 mm is stretched to a length of 200 mm at a tensile speed of 300 mm / min, and the presence or absence of pinholes on the surface of the binding tape is visually observed. It is determined. Those having no pinholes were evaluated as good (◯), and those having one or more pinholes were determined as defective (x).

  In Table 1, “flexibility” means that when the binding tape is wound around the wire / cable in a half wrap shape, the end of the terminal part is peeled off when the binding tape is wrapped around the wire / cable and the end of the winding is cut. The presence or absence was judged visually. Those with no floating or terminal peeling were evaluated as good (◯), and those with floating or terminal peeling were determined as poor (×).

  In Table 1, “operability” refers to the determination of usability when a binding tape is wound around a 1 mm diameter wire / cable. When the winding tape was not stretched or cut during winding, it was judged as good (◯), and when it was stretched or broken, it was judged as bad (x).

  In Table 1, “hand cutting property” refers to evaluation of the state of the cut surface of the binding tape by cutting the binding tape formed to a length of 100 mm in the horizontal direction with a human hand. A sample with a clean cut was defined as good (◯), and a sample with a cut extended was defined as defective (x).

  In addition, in “Comprehensive evaluation” in Table 1, a case where all the characteristic values were good (◯) was judged appropriate (◯), and a case where any one of the characteristic values was not satisfied was judged unsuitable (×).

(Example 1) The film base of the binding tape in this example was formulated with 100 parts of ethylene-ethyl acrylate (made by Mitsui DuPont) as an ethylene acrylate ester copolymer and a polypropylene random copolymer (Idemitsu) as a polypropylene resin. 60 parts), 30 parts of magnesium hydroxide (manufactured by Kamishima Chemical Co., Ltd.) as an inorganic filler with a particle size of 3.0 μm, and other small amounts of stabilizers, lubricants, and colorants. The back adhesive strength is 3.0 N / 10 mm. As a pressure-sensitive adhesive, it contains a rubber-based pressure-sensitive adhesive made of a mixture of natural rubber and SBR. This compounding agent is kneaded with a Banbury mixer, formed into a thickness of about 0.1 mm by calendering, and then a tape having a width of 25 mm. Then, the binding tape of Example 1 was obtained.

  In Example 1, all the characteristic values were evaluated as good, and a bundling tape having the desired flexibility, winding workability, hand cutting ability, and the like was obtained. The comparative examples described below are the same as the present examples unless otherwise specified.

  Example 2 The composition was the same as in Example 1 except that 30 parts of a polypropylene random copolymer and 30 parts of a reactor polypropylene (TPO) were used. All the characteristic values were evaluated as good, and the intended binding tape was obtained.

  Example 3 The composition was the same as in Example 1 except that the adhesive was changed from a rubber adhesive to an acrylic adhesive. All the characteristic values were evaluated as good, and the intended binding tape was obtained.

  (Comparative Examples 1 and 2) In Comparative Example 1 in which the blending amount of the propylene random copolymer of Example 1 was changed to 0.5 part, workability and hand cutting properties were obtained because the film substrate was too soft and stretched. There wasn't. Moreover, in the comparative example 2 which changed the compounding quantity of the propylene random copolymer of Example 1 to 300 parts, the film base material became hard and pinhole resistance and a softness | flexibility were not obtained.

  (Comparative Examples 3 to 4) In Comparative Example 3 in which the blending amount of magnesium hydroxide in Example 1 was changed to 0.5 part, the film base material became soft and workability and hand cutting properties were not obtained. In Comparative Example 4 in which the compounding amount of magnesium hydroxide in Example 1 was changed to 150 parts, the film base material became hard and pinhole resistance and flexibility were not obtained.

  (Comparative Examples 5 to 6) In Comparative Example 5 in which the particle size of magnesium hydroxide in Example 1 was changed to 0.3 μm, the film substrate became soft and workability and hand cutting properties were not obtained. In Comparative Example 6 in which the magnesium hydroxide particle diameter of Example 1 was changed to 15.0 μm, the film substrate became hard and pinhole resistance and flexibility were not obtained.

  Although not shown in Table 1, the heat deformation rate of Example 1 was −43%. This heat deformation rate is the deformation rate of the length in the longitudinal direction of the bundling tape that has been heat-treated at 140 ° C. for 5 minutes and then left at 23 ° C. for 30 minutes or more, and the bundling tape before treatment. This shows the temperature dependence of. As another example, when the film base material of Example 1 was crosslinked by irradiation with an electron beam of 20 Mrad, the heating deformation rate was −6%, and the temperature dependency was reduced.

Examples 1 and 2 have the same tensile strength, elongation at break, electrical insulation (volume resistivity value of 1 × 10 ¹² Ω · cm or more), electrical resistance and breakdown voltage equivalent to those of conventional polyvinyl chloride tapes. It was.

Claims (4)

The average of the film substrate measured with 100 parts of ethylene-ethyl acrylate polymer (i) 1 to 200 parts of a polypropylene random copolymer or a mixture of this and a reactor polypropylene (TPO) and (ii) laser diffraction particle size of 0.5 ~ 10 m, aluminum hydroxide, magnesium hydroxide, zirconium hydroxide, calcium hydroxide, potassium hydroxide, barium hydroxide, ammonium polyphosphate, polyphosphoric acid amide, oxide Jirikoniumu, magnesium oxide, zinc oxide , Titanium oxide, Molybdenum oxide, Hydrotalcite, Snakeite, Zinc borate, Anhydrous zinc borate, Zinc metaborate, Barium metaborate, Antimony trioxide, Antimony trioxide, Antimony pentoxide, Red phosphorus, Talc, Alumina, Silica, Boehmite , Bentonite Sodium silicate, calcium silicate, at least one binding tape comprising an inorganic filler 1-100 parts chosen calcium sulfate, calcium carbonate and magnesium carbonate.   The binding tape according to claim 1, wherein the film base material is crosslinked by irradiating with an electron beam.   The binding tape according to claim 1 or 2, wherein the back surface adhesive strength in accordance with JIS C 2107 is 1.5 to 5.0 N / 10 mm. The binding tape according to claim 1, wherein an adhesive layer is formed on one side of the film substrate.