CN100584915C - Adhesive and coating film for electrical material using same - Google Patents

Abstract

The invention provides and a kind ofly have the tackiness agent of excellent adhesiveproperties etc. and use this tackiness agent to form binder layer and weather resistance and the high electric material coating film of operability in temperature province wide from low temperature to the pyritous.This tackiness agent comprises the polyester thermoplastic resin or contains the hot melt based resin composition of this resin, described polyester thermoplastic resin has crystallinity, and to adopt the loss tangent (tan δ) in the temperature dispersion curve that Measurement of Dynamic Viscoelasticity obtains be 4.9 * 10 under-40 ℃～40 ℃ ^-2Or 4.9 * 10 ^-2More than, the peak-peak of this loss tangent (tan δ) is in-15 ℃～40 ℃ scope, and fusing point is 95 ℃～130 ℃.

Description

Adhesive and coating film for electrical material using same

technical field

The present invention relates to an adhesive and a coating film for electrical materials using the adhesive. In more detail, it relates to an adhesive having adhesiveness in a wide temperature range from low temperature to high temperature, an adhesive layer is formed using the adhesive, and heat bonding can be performed by methods such as thermal lamination or thermal pressing. Covering film for electrical materials suitable for applications such as covering the core wire of wiring wires such as electrical equipment or electronic equipment (for example, for reinforcing plates (protective tapes) for flexible flat cables).

Background technique

A laminated film having an adhesive layer bonded by thermal fusion generally includes a base material and an adhesive layer, and a biaxially stretched polyester film is used as the base material in consideration of mechanical strength and electrical insulation. For example, when it is necessary to impart flame retardancy to the laminated film, a flame retardant is added to the adhesive layer, and when it is necessary to impart concealment, a pigment or dye is added to the adhesive layer.

The above-mentioned laminated film is useful as a constituent member such as a flat wire used in wiring of electric equipment, electronic equipment, etc., and can be used for insulating protection by covering a core wire. A flat electric wire can usually be obtained by heat-compression-bonding a covered covering body and a laminated film using a heated roll or a heat press to integrate them. Therefore, a pressure-sensitive adhesive layer that can be integrated by heating and melting is required for a laminated film. As a material constituting the adhesive layer, a hot-melt resin mainly composed of vinyl chloride resin, polyester resin, polyolefin resin, or the like can be used.

For constituting the adhesive layer, polyester-based resins generally used have a glass transition temperature (Tg) of 0° C. or higher, and those whose Tg is around room temperature are often used. However, it was confirmed that the adhesive performance was significantly lowered with Tg as the boundary, and the adhesive sometimes peeled off from the adherend when used in winter or in a low-temperature region. In particular, in recent years, adhesiveness at low temperature has been demanded from the viewpoint of quality. Therefore, low temperature characteristics are improved by using what has Tg of -22 degreeC - 0 degreeC as a polyester type hot-melt resin composition (for example, refer patent document 1).

In addition, at the time when such improvement was carried out, there were no commercially available polyester-based hot-melt resins having a lower Tg, so there was a limit to improving low-temperature characteristics. However, the required performance is increasing year by year, and the use of the conventional low Tg polyester hot-melt resin cannot stably meet the requirement of maintaining good adhesive properties, and a polyester hot-melt resin with high adhesive performance and stability is required.

In addition, the laminated film having such an adhesive layer has strong self-adhesive (blocking) properties, and when it is made into a packaged product, it is often peeled off and misaligned, resulting in poor handling characteristics. Therefore, methods such as attaching a masking film to the surface of the adhesive have been adopted.

In recent years, there have been further demands on durability, but polyester-based hot-melt resins are no longer sufficient. For example, durability under high temperature and high humidity is also being emphasized, and use in fields requiring higher reliability is also increasing. For example, in a high-temperature and high-humidity environment with a temperature of 80°C and a humidity of 85%RH, when it is necessary to maintain an adhesive strength of 169 hours, the conventional laminated film has a lower cohesive force due to hydrolysis of the adhesive, and delamination occurs , In addition, when the multilayer film is used for covering signal lines, there is a problem that defects such as short circuits of signal lines occur.

In particular, when the above laminated film is used for a reinforcing plate (protective tape) used at an end portion of a flexible flat cable or the like, the end portion is inserted into a connector. In winter when the temperature drops, etc., the reinforcement board is bent and delamination is likely to occur, and it is required to improve the adhesive strength at low temperature.

Patent Document 1: JP-A-2001-279226

Contents of the invention

The problem to be solved by the invention

The present invention is made in view of the above circumstances, and its object is to provide an adhesive having excellent adhesive performance in a wide temperature range from low temperature to high temperature, and to use the adhesive to form an adhesive layer, and the durability It is a useful film for a coating film for electrical materials with high handleability, especially for a reinforcing plate (protective tape) used at the end of a flexible flat cable or the like.

means of solving problems

As a result of repeated intensive studies, the inventors of the present invention have found that the loss tangent (tan δ) in the temperature dispersion curve obtained by dynamic viscoelasticity measurement is specified, and a crystalline polyester-based hot-melt resin having a predetermined melting point or a resin containing the same The hot-melt resin composition can solve the above-mentioned problems, and based on this finding, the present invention has been completed.

That is, the present invention provides the following adhesives and coating films for electrical materials.

1. An adhesive, the adhesive comprising a polyester hot-melt resin or a hot-melt resin composition containing the resin, the polyester hot-melt resin has crystallinity, and is obtained by dynamic viscoelasticity measurement The loss tangent (tanδ) in the temperature dispersion curve is 4.9×10 ^-2 or more at -40°C to 40 ^° C, and the maximum peak value of the loss tangent (tanδ) is at -15°C to 40°C range, and the melting point (Tm) is 95°C to 130°C.

2. The adhesive according to 1 above, wherein the hot-melt resin composition contains 0.05 to 2 parts by mass of an oxazoline-based additive based on 100 parts by mass of the polyester-based hot-melt resin.

3. The adhesive according to the above 1, wherein the hot-melt resin composition contains 0.05 to 2 parts by mass of the carbodiimide-based additive based on 100 parts by mass of the polyester-based hot-melt resin.

4. A cover film for electrical materials obtained by forming an adhesive layer using the adhesive described in any one of 1 to 3 above on at least one surface of a plastic base material film.

5. The cover film for electrical materials according to the above 4, wherein the surface roughness of the adhesive layer is 10-point average roughness (Rz) of 1 μm or more.

6. The cover film for electrical materials according to the above 5, wherein the surface roughness of the pressure-sensitive adhesive layer is 10-point average roughness (Rz) of 10 μm or more.

7. The covering film for electrical materials according to any one of 4 to 6 above, which is bonded and used for reinforcement of electrical materials.

8. The covering film for an electrical material according to the above 7, wherein the electrical material is a flexible flat cable.

The effect of the invention

According to the present invention, an adhesive having adhesiveness in a wide temperature range from a low temperature to a high temperature can be obtained, and a coating film for electrical materials formed by laminating the adhesive has high durability and handling properties membrane.

Detailed ways

The adhesive of the present invention contains a crystalline polyester-based hot-melt resin or a polyester-based hot-melt resin composition containing the resin. The polyester-based hot-melt resin may also be a mixture of two or more kinds. In addition, the polyester-based hot-melt resin composition is a composition in which additives described later are added to the polyester-based hot-melt resin. Polyester-based hot-melt resins are polycondensation polymers of dibasic acids and diols. Specific examples of the dibasic acid include terephthalic acid, isophthalic acid, succinic acid, adipic acid, sebacic acid, and dodecanedioic acid. Examples of the diol include ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, cyclohexanediol, polyoxygen glycol and the like.

As the crystalline polyester-based hot-melt resin used in the present invention, compared to producing a polyester-based hot-melt resin having predetermined viscoelastic properties by polymerization, by mixing two kinds in a processing step such as an adhesive coating step The method of obtaining a polyester-based hot-melt resin having predetermined viscoelastic properties by using two or more polyester-based hot-melt resins is highly effective in improving self-adhesiveness described later.

In this case, an incompatible resin is preferable as the crystalline polyester-based hot-melt resin to be mixed. In the case of mixing incompatible polyester-based hot-melt resins, for example, polyesters that are crystalline and have a glass transition temperature (hereinafter, sometimes abbreviated as Tg) in the range of -5°C to 40°C A method in which a hot-melt resin is mixed with a low Tg polyester-based hot-melt resin below -5°C as the main component. At this time, resin with a Tg of -5°C to 40°C exists in the domain part, and since the resin below -5°C that improves low-temperature characteristics exists as a matrix, low-temperature characteristics can be maintained and self-adhesiveness can be improved.

On the other hand, when mixing compatible polyester-based hot-melt resins, even if a resin of a binary system or more than a binary system is used, the mutual Tg or melting point (hereinafter , sometimes abbreviated as Tm) causes interaction, so it causes Tg to rise or Tm to fall. Therefore, in the end, it will be in the same state as when a mono-system resin is used, and there is a concern that a sufficient effect cannot be obtained.

In addition, when an amorphous resin having a low Tg is used, in the coating film for electrical materials of the present invention described later, even if embossing is applied to the adhesive layer, the shape of the embossing is broken over time, and the contact The area gradually increases, and the self-adhesiveness becomes high, causing problems during use. The above disadvantages can be improved by using a crystalline polyester-based hot-melt resin.

As the polyester-based hot-melt resin, for example, commercially available ones can be used. Specifically, Toyobo Co., Ltd. product names "Byron GM900", "Byron GM920", "Byron GA6400", Toyo Trade names "Byron GM990", "Byron GA5410", "Byron GM995" manufactured by Bosei Co., Ltd., "Aron Melt PES111", "PES111EE", "Aron Melt PES120E", "Aron Melt PES120H" manufactured by Toagosei Co., Ltd. ", Toray Co., Ltd. product name "Kemitsuto R248", etc., and by mixing them as necessary, the desired polyester-based hot-melt resin can be obtained.

When the adhesive constituting the adhesive layer uses only one type of polyester hot-melt resin as an active ingredient, it is necessary to make the loss tangent (tanδ) in the temperature dispersion curve obtained by dynamic viscoelasticity measurement be between -40°C and 40°C. The range is 4.9×10 ^{-2 or} more. When a mixture of two or more polyester-based hot-melt resins is used as an active ingredient, the loss tangent (tanδ) in the mixture needs to be 4.9×10 ^-2 or 4.9× in the range of -40°C to 40°C 10 ^-2 or more.

In addition, in the present invention, the melting point (Tm) of the polyester-based hot-melt resin needs to be in the range of 95 to 130°C, and is preferably in the range of 100 to 120°C. The polyester hot-melt resin is a crystalline substance, and when the Tm is 95°C or higher, the heat resistance is improved, and when the Tm is 130°C or lower, the adhesion of the coating film for electrical materials of the present invention is improved. Good adhesion. When using a mixture of two or more polyester-based hot-melt resins, the Tm of the mixture is in the range of 95 to 130°C, and within the range that does not impair the effect of the present invention, it is also possible to mix Tm of 95 to 130°C. Polyester-based hot-melt resins outside the ℃ range. In addition, in the following description, polyester-type hot-melt resin also includes the case where the mixture of two or more types is mixed.

The maximum peak of the above-mentioned loss tangent (tan δ) of the polyester-based hot-melt resin used in the present invention needs to be in the range of -15°C to 40°C, and from the viewpoint of workability (blocking resistance), it is preferably -5°C or - Resin above 5°C.

In polyester hot-melt resins, the ester group located in the polymer backbone is easily decomposed by moisture, especially the accelerated decomposition by moisture and heat, which is prone to decrease the adhesive force due to the decrease of molecular weight. In order to prevent this decrease in adhesive force, a polyester-based hot-melt resin composition in which an oxazoline-based additive and/or a carbodiimide-based additive is added to a polyester-based hot-melt resin is preferable as the binder. When extruding this resin composition, three-dimensional crosslinking proceeds, improving the durability against heat and humidity. It remains fully cohesive even after hours.

The oxazoline-based additives or carbodiimide-based additives have the effect of trapping acid components that promote hydrolysis during extrusion processing or wet heat durability tests. In addition, since there is an effect of chain extension by reacting with the terminal acid of the polyester component generated by decomposition, the molecular weight of the polyester-based hot-melt resin can be prevented from decreasing.

Oxazoline additives or carbodiimide additives theoretically increase the more they are added, and the durability increases. However, if the crosslinking reaction during processing proceeds excessively, it is necessary to increase the viscosity or cause gelation. Note that it is necessary to determine the amount to be added in consideration of processing stability and heat and humidity resistance.

Therefore, the addition amount of the oxazoline-based additive, the carbodiimide-based additive, or a combination of these additives is preferably in the range of 0.05 to 2% by mass relative to 100 parts by mass of the polyester-based hot-melt resin, in order to improve processability. In view of this, it is more preferably 0.05 to 0.5% by mass. As the oxazoline additives used in the present invention, for example, commercially available ones can be used, specifically, Mikuni Chemical Co., Ltd. product name "1-3PBO", (KK) Nippon Catalyst Co., Ltd. product Trade name "EPOCROS RPS-1005" etc. Examples of carbodiimide-based additives include Nisshin Industries Co., Ltd. product name "Calvodilite HMV08CA", Bayer Co., Ltd. product names "Stabacure I", "Stabacure P", etc. .

In order to improve workability or functionality, the adhesive of the present invention may contain a polyolefin resin, epoxy resin, or the like as an active ingredient, if necessary. They also have stress relaxing and crystallization promoting effects. Examples of polyolefin-based resins include high-density polyethylene, low-density polyethylene, ultra-low-density polyethylene, linear low-density polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate Copolymer, ethylene-vinyl acetate-maleic anhydride terpolymer, ethylene-ethyl acrylate-maleic anhydride terpolymer, ethylene-glycidyl methacrylate copolymer, ethylene-vinyl acetate-methacrylate shrink Glyceride terpolymer, ethylene-ethyl acrylate-glycidyl methacrylate terpolymer, etc. These may be used alone or in combination of two or more. Adhesive function-imparted substances, such as acid modification, can also be used as needed. However, when an acid-modified adhesive resin is used, there is a concern that hydrolysis may occur during extrusion processing or a heat-and-moisture durability test, etc., resulting in performance degradation.

In addition, as the epoxy resin, either bisphenol A type or novolac type can be used, but from the viewpoint of compatibility and adhesiveness, bisphenol A type epoxy resin with a softening point of about 100°C is preferable. . In addition, since epoxy resin is particularly effective in bonding metals, adding a small amount according to the application can improve the bonding strength to metals. However, if it is added in excess of the necessary amount, it may conversely have adverse effects due to bleed-out during the film forming process, so care must be taken.

The addition amount of polyolefin resin is about 1-40 mass parts normally with respect to 100 mass parts of polyester-type hot-melt resins, Preferably it is 5-10 mass parts. The addition amount of an epoxy resin is about 1-10 mass parts normally with respect to 100 mass parts of polyester-type hot-melt resins, Preferably it is 2-5 mass parts.

Flame retardancy is often required for products coated with the coating film for electrical materials of the present invention. Therefore, in order to make the coating film itself self-extinguishing, the adhesive layer of the coating film, that is, the adhesive of the present invention preferably contains a flame retardant. As the flame retardant, flame retardants based on halogen compounds such as bromine and chlorine are particularly preferred, but known additive flame retardants such as phosphorus, nitrogen, and metal hydroxides can also be used. mixture. These flame retardants can be used in an additive amount within a range that does not adversely affect the physical properties of the adhesive.

The adhesive of the present invention preferably has moderate fluidity from the viewpoint of workability. The melt viscosity value, which is an index of moderate fluidity, is preferably in the range of 300 to 5000 Pa·s as measured by an elevated pour point tester at a measurement temperature of 160°C and a shear rate of 10 sec ⁻¹ . If the melt viscosity of the adhesive is 300 Pa·s or more, the adhesive will not bleed out from the plastic film as the substrate when processing under heat and pressure, so there is no risk of trouble in production sex. In addition, if the melt viscosity is 5000 Pa·s or less, the fluidity is also sufficient, so there will be no troubles such as generation of voids between the coating body and the coating film.

The covering film for electrical materials of the present invention is a covering film in which an adhesive layer is formed using the above-mentioned adhesive on at least one surface of a plastic base material. In addition, in general, the boundary between a film and a sheet is not clear, and it is difficult to clearly distinguish it. However, the "film" in the present invention includes both the film and the sheet. In the present invention, the thickness of the pressure-sensitive adhesive layer is preferably in the range of 0.1 to 2.0 times the thickness of the plastic base material film in consideration of the thickness of the object to which the cover film is applied.

In the present invention, the pressure-sensitive adhesive layer has a function of exhibiting adhesiveness at low temperature. When an adhesive having a low Tg is used, since the processing is often performed at a temperature of Tg or higher, when a cover film for electrical materials is used, blocking tends to occur on the cover film. In particular, blocking is likely to occur when the cover film is wound on a roll until the crystallization of the crystalline polyester-based hot-melt resin as the main component is completed.

Therefore, as a method for preventing blocking, the method described below is preferable. That is, as long as the crystalline polyester-based hot-melt resin, which is the main component of the adhesive, is sufficiently crystallized, the self-adhesiveness will be low and will not hinder the workability. Time, therefore, it is necessary to minimize the contact area of the adhesive surface as much as possible. Therefore, in order to lower the self-adhesiveness until the crystallization is sufficient, it is appropriate to provide fine unevenness on the surface of the adhesive layer.

Specifically, the surface roughness of the adhesive layer is preferably 10-point average roughness (Rz) of 1 μm or more, more preferably 10 μm or more. In particular, the coating film is provided with such minute irregularities, and the polyester-based hot-melt resin is crystallized after the coating film is rolled up, so that the film forming speed can be increased. However, the surface roughness is easily affected by the winding state of the film. When the winding tension is strong, the surface roughness of the adhesive may change, so care is required.

As a method of providing fine unevenness on the surface of the adhesive layer, during the manufacture of the cover film described later, and when the resin temperature is high, when the cover film is taken up with a roll, it can be used on both sides. A method of transferring an embossment to a roughened chill roll, or a method using an embossed film to transfer the embossment on the surface of the adhesive layer.

In addition, when the surface of the adhesive layer is flat, when using a hot-press type lamination machine to bond the cover film, since the temperature of the bottom surface of the processing machine itself rises significantly during the hot-press preheating, the adhesive surface starts to melt with residual heat, It becomes a false close state with the object to be bonded, and it is difficult to extract the entrapped air during the bonding, and air bites frequently occur between the object to be bonded, so that sufficient bonding strength cannot be obtained. question. Or due to the biting of air, the coating film exceeds the specified thickness.

For such a problem, by performing fine embossing on the surface of the pressure-sensitive adhesive layer, even when using a hot-press type laminating machine, the bonding process characteristics can be improved.

In the coating film of the present invention, as the plastic base material film, for example, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polymethyl Pentene (manufactured by Mitsui Petrochemical Industries Co., Ltd., trade name "TPX", stretched polypropylene (OPP), unstretched polypropylene (CPP) and other films. From the perspective of mechanical strength and heat resistance, preferred The polyethylene terephthalate (PET) film and the polyethylene naphthalate (PEN) film are especially preferably a biaxially stretched PET film and a biaxially stretched PEN film.

In the present invention, the thickness of the plastic base material film is not particularly limited, and it can usually be about 12 to 250 μm.

As a method of forming an adhesive layer on the above-mentioned plastic base material film using the above-mentioned adhesive, a so-called solvent coating method in which an adhesive component or the like is dispersed in a solvent and then coated on a base material can be used, and Although any of the so-called solvent-free coating methods that do not use a solvent, in the present invention, it is preferably produced by a so-called solvent-free coating method.

In the solventless coating method, a common ink coating method can be used, and the coating method can be applied or determined according to the melt viscosity or thermal stability of the binder. For example, it is possible to knead the components of the adhesive uniformly using an extruder or a kneader, then temporarily cool it, and reheat it with a hot-melt high-frequency heating electrode, etc., and use a slit coater A method of coating on a base material while kneading uniformly, etc. Alternatively, after uniformly kneading the components of the adhesive and forming a film into a film, the film adhesive and the base material can be bonded together to form a coating film. Bonding can be performed, for example, by methods such as heating and pressing.

In order to improve the adhesion between the plastic base material film and the adhesive layer, corona discharge treatment can be implemented on the adhesive layer side of the base material film, and an adhesion-promoting coating can also be provided on the base material film if necessary. layer ). Examples of the adhesive for anchor coating used in the anchor coating include polyester-based, polyurethane-based, acrylic-based, vinyl chloride-vinyl acetate copolymer-based adhesives, and the like. In addition, it is preferable to use a coating method such as a roll coating method or a gravure coating method for coating the adhesive for thickening coating.

In the present invention, the layer of the tackifier coating adhesive is laminated before stretching the base material film, and the tackifier coating layer may be formed by simultaneously stretching the base material and the layer of the tackifier coating adhesive. The thickness of the adhesion-promoting coating can generally be about 0.1-5 μm.

Example

Hereinafter, although an Example demonstrates this invention in more detail, this invention is not limited to these examples at all. In addition, various measurements and evaluations of the polyester-based hot-melt resins used in Examples and the like were performed as follows.

(1) Determination of glass transition temperature (Tg) and melting point (Tm)

Using a differential scanning calorimeter (Perkin Elma), measure the glass transition temperature (Tg) and melting point (Tm) of polyester-based hot-melt resins at a temperature of -60°C to 200°C and a scanning speed of 10°C/min. ).

(2) Determination of the loss elastic modulus in the temperature dispersion curve obtained by dynamic viscoelasticity measurement

The loss elastic modulus in the temperature dispersion curve obtained by the dynamic viscoelasticity measurement of the polyester-based hot-melt resin composition or hot-melt resin was measured using a dynamic viscoelasticity measuring device (manufactured by Ai Tai Yi Ace Japan Co., Ltd.) . The measurement conditions are deformation mode stretching, temperature -100° C. to measurement limit temperature, and a heating rate of 3° C./min.

(3) Determination of 10-point average roughness (Rz)

The surface roughness of the pressure-sensitive adhesive layer was measured using a three-dimensional roughness measuring machine (manufactured by Kosaka Laboratories).

Examples 1-5 and Comparative Examples 1-4

The polyester-based hot-melt resins shown in Table 1-1 and Table 1-2 were used as adhesives. When mixing two kinds of resins, use a Henschel mixer to fully premix the polyester hot-melt resins in the amount shown in Table 1-1 and Table 1-2, and put them into the temperature setting to come out from the nozzle. After extruding into a sheet form in an extruder with a resin temperature of 180° C., it was cooled with a casting roll to form a film for an adhesive layer with a thickness of 50 μm. When one kind of polyester-based hot-melt resin is used, it is charged into the extruder without pre-mixing.

A base material film [100 μm thick biaxially stretched polyethylene terephthalate ( PET) film] and the film for the adhesive layer were bonded together to produce a laminated film having an adhesive layer.

Since the surface of the adhesive layer of the obtained laminated film is roughened, the surface roughness is transferred to the surface of the adhesive layer with a roughened cooling roll after heat lamination and before the resin is cured. Make the wrapping film.

The following evaluations were performed on the obtained coating film. The results are shown in Table 1-1 and Table 1-2. In addition, the obtained evaluation results of adhesiveness, handleability, heat resistance, and adhesion were evaluated comprehensively, and "◎" was extremely good, "○" was good, "△" was slightly better, and "×" Because it is not practical.

(1) Preparation of sample 1 for evaluation

The 2 sheets of the obtained covering films were stacked so that the adhesive layers faced each other, and were sandwiched between a set of rolls (metal roll/rubber roll) consisting of a heated metal roll and an unheated rubber roll. ) between the roller nip (nip) pressure of 98N/cm (linear pressure), bonding speed of 0.5m/min under the conditions of bonding, the preparation of the sample 1 for evaluation. When the adhesive contains two types of polyester-based hot-melt resins, the bonding temperature is 20°C higher than the melting temperature of the resin with a higher Tm among these resins.

(2) Evaluation of Low Temperature Adhesiveness (Measurement of Peel Strength)

The prepared evaluation sample 1 was cut into a width of 10 mm, and used in a tensile testing machine (material testing machine "201X" with a constant temperature bath, Co., Ltd. ) manufactured by Intesco) The 180-degree peel strength of the sample was measured at a peeling speed of 10 mm/min. The measurement results were evaluated based on the evaluation criteria shown below, and indicated with symbols. In the present invention, as long as the measured value is 500 g/cm or more, it is a practically acceptable level.

<Evaluation criteria>

1500g/cm or more than 1500g/cm or coagulation failure, matrix material failure: A

1000g/cm or more than 1000g/cm but less than 1500g/cm: B

500g/cm or more but less than 1000g/cm: C

Less than 500g/cm: D

(3) Evaluation of heat resistance

The prepared evaluation sample 1 was cut into a size of 60 mm×90 mm, and stood at an angle of 45 degrees in an oven at 100° C. to check whether there was flow of the adhesive or warping of the sample. At this time, when either the flow of the adhesive or the warping of the sample was not confirmed, the evaluation was "good", and even if only any of the flow of the adhesive or the warping of the sample was confirmed, Rated as "Bad".

(4) Operational evaluation

Evaluation of blocking resistance (blocking resistance) a, b was performed. The obtained covering film was cut into a width of 5 cm and a length of 20 cm. Two cut coating films were stacked so that the adhesive layers faced each other, and a load of 4.9 N was applied in an oven at a temperature of 40° C., held for 24 hours, and then taken out to prepare a sample a for evaluation. In addition, the adhesive layer of the cut coating film was superimposed on the untreated PET film (thickness 100 μm), and the obtained material was applied with a load of 4.9 N in an oven at a temperature of 40 ° C, kept for 24 hours, and then taken out. Sample b for evaluation was prepared.

For the obtained two kinds of evaluation samples a and b, a tensile tester (material testing machine "201X" with constant temperature layer, manufactured by Intesco Co., Ltd.) was used in an atmosphere of 23°C to measure 180 Peel strength was used to evaluate the blocking resistance of samples a and b based on the following criteria. As long as the measured value is less than 300 g/cm, it is a practically acceptable level.

<Evaluation criteria>

Less than 100g/cm: A

100g/cm or more but less than 300g/cm: B

300g/cm or more than 300g/cm: C

(5) Adhesiveness (evaluation of adhesion in an atmosphere of 23°C)

The obtained covering film was cut into a width of 30 cm and a length of 40 cm. Two cut coating films were stacked so that the pressure-sensitive adhesive layers faced each other, held at a press temperature of 120° C. and a pressure of 0.3 MPa for 1 minute, and then cooled to room temperature to prepare a sample c for evaluation. In addition, the adhesive layer of the obtained coating film was cut into a sample with a width of 30 cm and a length of 40 cm, laminated on an untreated PET film (thickness 100 μm), and held at the same pressing temperature and pressure as above for 1 minute. , cooled to room temperature, and prepared evaluation sample d.

The obtained two kinds of evaluation samples c and d were measured at a peeling speed of 10 mm/min using a tensile tester (material testing machine "201X" with a constant temperature bath, manufactured by Intesco Co., Ltd.) in an atmosphere of 23°C. 180 degree|times peeling strength evaluated sticking characteristic c, d based on the reference|standard shown below. As long as the measured value is 1000 g/cm or more, it is a practically acceptable level.

<Evaluation criteria>

1500g/cm or more than 1500g/cm or coagulation failure, matrix material failure: A

1000g/cm or more than 1000g/cm but less than 1500g/cm: B

500g/cm or more but less than 1000g/cm: C

Less than 500g/cm: D

[Table 1]

Table 1-1

[Table 2]

Table 1-2

(Note)

1) Bilon GM920: Polyester-based hot-melt resin, manufactured by Toyobo Co., Ltd., trade name

2) Bilon GA6400: Polyester-based hot-melt resin, manufactured by Toyobo Co., Ltd., trade name

3) Aronmelt PES111: Polyester-based hot-melt resin, manufactured by Toagosei Co., Ltd., trade name

4) Aronmelto PES120H: Polyester-based hot-melt resin, manufactured by Toagosei Co., Ltd., trade name

5) Aronmelto PES126E: Polyester-based hot-melt resin, manufactured by Toagosei Co., Ltd., trade name

6) Kemituto R248: Polyester-based hot-melt resin, manufactured by Toray Co., Ltd., trade name

As can be clearly seen from Table 1-1 and Table 1-2, the coating films of Examples 1 to 5 exhibit excellent adhesiveness in the low temperature range of 0°C or below, and do not produce stickiness in the high temperature range of 100°C. The flow of the mixture does not cause deformation of the base material, and it can be bonded well at a temperature of 120 ° C. Moreover, since the surface roughness of Rz of 1 μm or more is formed on the surface of the adhesive layer, it is also suitable for low-temperature materials. Materials with excellent operability and processability can be provided. That is, it can be seen that these coating films are high-level coating films that can be put to practical use in any of the evaluations, and therefore show a good level or more in the overall evaluation.

Example 6

The additives of the type and amount shown in Table 2-1 and Table 2-2 are added to the adhesive components used in Example 1, fully premixed with a Henschel mixer, and put into the temperature setting as from the nozzle The resulting resin was extruded into a sheet at a temperature shown in Table 2 in an extruder, and then cooled with a casting roll to form a film for an adhesive layer with a thickness of 50 μm.

The base material [biaxially stretched PET film with a thickness of 100 μm] and the formed adhesive layer applied with polyurethane-based tackifier coating were used for Film lamination to produce a laminated film with an adhesive layer.

In order to roughen the surface, the adhesive surface of the laminated film is heated and laminated, and before the resin is cured, the surface roughness is transferred to the surface of the adhesive layer with a roughened cooling roll, and the package is produced. lamination.

In addition, for comparison, the same operation was performed on a sample without adding an additive, and a coating film was produced. The following evaluations were performed on the obtained coating film. The results are shown in Table 2-1 and Table 2-2.

(1) Evaluation of moisture and heat resistance

The prepared evaluation sample 1 was cut into a width of 10 mm, placed in a high-temperature, high-humidity tank under a high temperature and high humidity of 80° C.×85% RH, and peeling evaluation was performed after 169 hours.

<Evaluation criteria>

Peel strength maintains 80% or more compared to the initial stage: A

Peel strength maintains 60% or more compared to the initial stage: B

Peel strength maintains 40% or less relative to the initial stage: C

(2) Evaluation of extrusion stability

A 10 m ² (1 m×10 m) PSA sheet after extrusion for 8 hours was collected, and a crosslinked gel of 50 μm or more was evaluated based on the following evaluation criteria.

<Evaluation criteria>

Non-cross-linked gel: A

1 piece/1000m ² or more than 1 piece/1000m ² but less than 10 pieces/1000m ² of cross-linked gel: B

10 pieces/1000m ² or more than 10 pieces/1000m ² of cross-linked gel: C

[table 3]

table 2-1

[Table 4]

Table 2-2

(Note)

1) Carbodiline HMV-8CA: carbodiimide-based additives, manufactured by Nisshin Industries, Ltd., brand name

2) Starbuckell P: carbodiimide-based additives, manufactured by Bayel Co., Ltd., trade name

3) Epocross RPS-1005: oxazoline additive, manufactured by Japan Catalyst Co., Ltd., trade name

4) Parts by mass relative to 100 parts by mass of the binder component

Example 7

Add additives of the type and amount shown in Table 3 to the binder component used in Example 4, fully pre-mix with a Henschel mixer, and put into the temperature setting so that the temperature of the resin coming out of the nozzle is as shown in Table 3 In the extruder at the indicated temperature, after extruding into a sheet form, it was cooled with a casting roll to form a film for an adhesive layer with a thickness of 50 μm.

The base material [biaxially stretched PET film with a thickness of 100 μm] and the formed adhesive layer applied with polyurethane-based tackifier coating were used for Film lamination to produce a laminated film with an adhesive layer.

In order to roughen the surface, the adhesive surface of the laminated film is heated and laminated, and before the resin is cured, the surface roughness is transferred to the surface of the adhesive layer with a roughened roller to form a coating. membrane.

In addition, for the sake of comparison, the same operation was performed on the sample without adding the additive, and a coating film was produced. The same evaluation as in Example 6 was performed on the obtained coating film. The results are shown in Table 3.

[table 5]

table 3

(Note)

1) Carbodiline HMV-8CA: carbodiimide-based additives, manufactured by Nisshin Industries, Ltd., brand name

2) Starbuckell P: carbodiimide-based additives, manufactured by Bayel Co., Ltd., trade name

3) Parts by mass relative to 100 parts by mass of the binder component

As can be seen from Table 2-1, Table 2-2, and Table 3, by adding carbodiimide-based additives to the binder components, the heat and humidity resistance is remarkably improved. On the other hand, in the system without additives, a significant performance decrease of 40% was confirmed with respect to the initial adhesive performance.

In addition, it can be seen that in the case of high-temperature extrusion with additives or a large amount of additives, although the heat and humidity resistance itself improves, due to the intense reaction, the increase in cross-linking points and the increase in cross-linking density occur. Therefore, extrusion for a long time When it was taken out, it was defective in appearance due to the generation of a gel substance.

Industrial Applicability

The coating film for electrical materials in which the adhesive layer is formed using the adhesive of the present invention can be thermally bonded by heat lamination or hot pressing, and can be used to coat core wires of wiring wires such as electric equipment or electronic equipment. , especially a reinforcing plate (protective tape) used in an end portion of a flexible flat cable or the like is useful.

Claims (8)

1. tackiness agent, this tackiness agent comprises polyester thermoplastic resin or polyester thermoplastic resin composition, described polyester thermoplastic resin has crystallinity, and to adopt the loss tangent (tan δ) in the temperature dispersion curve that Measurement of Dynamic Viscoelasticity obtains be 4.9 * 10 under-40 ℃～40 ℃ ^-2Or 4.9 * 10 ^-2More than, the peak-peak of this loss tangent (tan δ) is in-15 ℃～40 ℃ scope, and fusing point (Tm) is 95 ℃～130 ℃.

2. according to the described tackiness agent of claim 1, wherein polyester thermoplastic resin composition contains 0.05～2 quality Fen De oxazoline class additive with respect to 100 mass parts polyester thermoplastic resins.

3. according to the described tackiness agent of claim 1, wherein polyester thermoplastic resin composition contains the Carbodiimides additive of 0.05～2 mass parts with respect to 100 mass parts polyester thermoplastic resins.

4. electric material coating film, its right to use of one side at least profit at the plastic matrix material film require each the described tackiness agent in 1～3 to form binder layer to obtain.

5. according to the described electric material coating film of claim 4, wherein the surfaceness of binder layer is that 10 mean roughness (Rz) are 1 μ m or more than the 1 μ m.

6. according to the described electric material coating film of claim 5, wherein the surfaceness of binder layer is that 10 mean roughness (Rz) are 10 μ m or more than the 10 μ m.

7. according to each described electric material coating film in the claim 4～6, it is to fit to use in the enhancing purposes of electric material.

8. according to the described electric material coating film of claim 7, wherein electric material is the flexible ribbon cable.