KR20000023728A - Flat cable and method of manufacturing the same - Google Patents

Abstract

PURPOSE: A flat cable is provided to apply a press-coating process in manufacturing the cable having a superior bending characteristic. CONSTITUTION: A flat cable having a superior bending characteristic comprises: a pluralityof flat type conductors disposed in parallel; and an insulated resin layer at least contacting the flat type conductors. The flat type conductors are buried in the insulated resin layer and the insulated resin layer is a press-coating layer composed of thermoplastic resin having a bending elastic rate of 800 to 2400 MPa.

Description

Flat cable and its manufacturing method {FLAT CABLE AND METHOD OF MANUFACTURING THE SAME}

For example, the printing portion of the printer is connected to the transmission mechanism of the operation signal with a flat cable, and receives a operation signal from the transmission mechanism to perform a predetermined print operation. In the course of the print operation, the flat cable violently repeats the stretching motion. Therefore, the flat cable used in such a field is required not to be disconnected even in a long time repeated bending.

Herein, repeated bending refers to repeating the operation of changing the bending radius of the flat cable or moving the bending part.

Conventionally, as the flat cable repeating the above-described stretching motion, one having a cross-sectional structure shown in FIG. 1 is known.

In the case of this flat cable (A), the layer (2) which consists of adhesive resin compositions, such as a saturated polyester copolymer, between resin films 3 and 3 like an electrically insulating polyethylene terephthalate film as an outer layer, A plurality of flat conductors 1 (4 in the drawing) arranged in parallel in the inner layers 2 and 2 are formed as an inner layer, and the inner layers 2 and 2 are embedded at predetermined intervals. The above-mentioned inner layer 2 and outer layer 3 constitute an insulating resin layer of this flat cable.

This flat cable A is manufactured using the manufacturing line shown in FIG.

That is, first, the plurality of flat conductors 1 are sent out from the bobbin 4 in a state where they are arranged in parallel at a predetermined interval. And from the pair of rolls 5a and 5b, the resin films 3a and 3b in which the layers 2 and 2 of the adhesive resin composition are formed on the surface of the flat conductor 1 side are sent out, and the In contact with the upper and lower surfaces of one of the flat conductors 1, they are introduced to the roll surfaces of the pair of heating rolls 6a and 6b, and the whole is hot pressed to become the flat cable A shown in FIG. It is wound. Moreover, when adhesive resin composition is a thing of thermal crosslinking | crosslinking, crosslinking advances simultaneously with thermocompression bonding in the process which passes this heating roll 6a, 6b.

In the above-described production line, an important problem in relation to the characteristics of the flat cable is that the flat conductor 1 is in close contact with the inner layer 2 so that both are not peeled off, and the outer resin films 3a and 3b are also in the inner layer. (2,2) is in close contact with each other. This is because if such a state is insufficient, it may peel off from each other during the above-described stretching movement, resulting in a malfunction of the flat cable.

When manufacturing a flat cable with the manufacturing line shown in Fig. 2, the conditions such as the traveling speed of the flat conductor 1, the temperature and pressure applied by the heating rolls 6a and 6b are related to the requirements for the flat cable to be manufactured. Appropriately selected. In order to increase the productivity at the time of flat cable production, it is preferable to basically increase the line speed.

However, if the line speed of the production line is set to a certain speed or more, even if the temperature and pressure in the heating rolls 6a and 6b are adjusted, the adhesive force between the inner layers 2 in the flat cable A coming out of the heating roll is weakened. There is a problem that does not become a flat cable that can withstand the stretching movement of the.

This is because the amount of heat supplied from the heating rolls 6a and 6b to the inner layers 2 and 2 through the resin films 3a and 3b is insufficient. As a result, the softening of the adhesive resin composition of the inner layer 2 and the accompanying adhesive force thereof are reduced. This is because it is not sufficiently expressed.

From this, the manufacture of the flat cable A is tried using the manufacturing line shown in FIG.

This manufacturing line arrange | positions a pair of heating roll 6c, 6d further downstream of the heating roll 6a, 6b in the manufacturing line shown in FIG. 2, and the flat cable which came out from the heating roll 6a, 6b. This is a line to heat press again. In the case of this line, since the amount of heat from the heating rolls 6c and 6d is further added to the inner layer 2, the overall line speed can be increased as compared with the production line shown in FIG.

However, even in this manufacturing line, it is difficult to realize a large line speed, and as a current state, the line speed can only be increased up to several m / min.

By the way, in the manufacturing line of an electric wire, the method of extrusion coating insulating resin to a conductor is used a lot. This extrusion coating method is considered to be promising for increasing the line speed in the production line of flat cables. In fact, Japanese Patent Laid-Open No. 49-57381, Japanese Patent Laid-Open No. 62-206710, and Japanese Patent Laid-Open No. Hei 1-276514 all disclose a method of manufacturing a flat cable by an extrusion coating method.

For example, Japanese Laid-Open Patent Publication No. 49-57381 covers a plurality of insulated conductors to extrude a hollow resin tube, and then guides the whole to a pair of rolls having annular grooves, and the hollow tube is thermally deformed. The method of making a flat cable is proposed.

However, in this prior art, an insulated conductor must be prepared in advance, and a roll having an annular groove is required, so that the manufacturing cost is increased, and the whole insulation layer is formed by the insulation layer of the insulated conductor and the deformed hollow tube layer. The two-layer structure not only increases the material cost but also makes it difficult to form a thin insulating layer. Therefore, a flat conductor is used as a conductor, and it is unsuitable as the manufacturing method of the flat cable which requires the outstanding flexibility.

Japanese Laid-Open Patent Publication No. 62-206710 proposes a method for producing a flat cable in which a resin is extruded and coated on a conventional round conductor, and the resin is introduced into a molding machine having a desired cross-sectional shape when the resin is in a semi-melt state and cooled and solidified. have.

In this prior art, however, it is very difficult to use flat conductors as conductors and to coat them with a uniform and thin insulating layer. Therefore, it is virtually impossible to obtain a thin flat cable with excellent flexiblity in this prior art.

Japanese Unexamined Patent Application Publication No. Hei 1-276514 discloses a flat cable manufactured by extruding a soft insulator onto a plurality of flat conductors, taking into account the heat shrinkage of the soft insulator in the extrusion coating, and adjusting the spacing between the flat conductors. A method is proposed.

However, in this prior art, nothing has been examined regarding the characteristic that disconnection does not occur when the obtained flat cable is repeatedly stretched. In addition, the embodiment of the prior art shows that after the end of the extrusion coating is cooled with water, but if the extrusion coating layer is thin, the problem is that the entire flat cable is curved when cooled with water as described above.

As described above, although each of the above prior arts discloses a flat cable manufactured by the extrusion coating method, it is difficult to say that these flat cables have excellent flexibilities.

The present invention relates to a flat cable and a method for manufacturing the same. More particularly, the present invention relates to a flat cable, and more particularly, has excellent life characteristics during repeated bending, and can be used as a cable for a steering rotary connector or a harness cable of an automobile, for example. Flat cable and how to manufacture it under high productivity.

1 is a cross-sectional view showing a cross-sectional structure of a conventional flat cable example (A);

2 is a schematic view showing an example of a production line of a conventional flat cable;

3 is a schematic view showing an example of another conventional production line;

4 is a sectional view showing a cross-sectional structure of an example (B1) of a flat cable of the present invention;

5 is a schematic view showing a production line of the flat cable of the present invention;

6 is a plan view showing the positional relationship between the extruded needle pole and the extrusion die in the crosshead;

7 is a side view showing the positional relationship between the extruded needle pole and the extrusion die in the crosshead;

8 is a sectional view showing a cross-sectional structure of an example (B2) of another flat cable of the present invention;

9 is a cross-sectional view showing a cross-sectional structure of an example (B3) of still another flat cable of the present invention.

SUMMARY OF THE INVENTION An object of the present invention is to provide a flat cable having superior flexibilities (flexibility) compared to a conventional flat cable, and a flat cable manufacturing method which can significantly increase the line speed of a manufacturing line in order to apply an extrusion coating method. To provide.

In order to achieve the above object, in the present invention, in the flat cable in which a plurality of parallel conductors arranged in parallel are embedded in the insulating resin layer, at least the insulating resin layer in contact with the flat conductor is thermoplastic with a bending modulus of 800 to 2400 MPa. A flat cable comprising an extruded coating layer made of a resin is provided, and a plurality of flat conductors are arranged in parallel and sent to the crosshead of the extruder, and the thermoplastic resin having a bending elastic modulus of 800 to 2400 MPa is supplied to the crosshead. Provided is a method of manufacturing a flat cable, wherein the conductor is subjected to extrusion coating.

4 shows a cross-sectional structure of a first example of a flat cable of the present invention.

In this flat cable B1, the flat conductors 1 arranged in parallel at predetermined intervals are embedded in an extruded coating layer 8 made of a thermoplastic resin described later and functioning as an insulating resin layer.

In the case of this flat cable (B1), the extruded coating layer (8) is an insulating resin layer because the extruded coating layer (8) is not a bonding structure of two films, but is an integrated structure as in the conventional flat cable (A) shown in Fig. 1. The situation in which the upper surface portion 8a and the lower surface portion 8b of 8) are peeled off does not occur. That is, even if the whole is repeatedly stretched, the pressure applied locally to the flat conductor 1 is properly dispersed, so that the extrusion coating layer 8 is not separated by the stress at the time of stretching.

Moreover, although it is preferable that the flat conductor 1 and the extrusion coating layer 8 adhere | attached with each other, both do not necessarily need to be in the bonded state. In the formation of the extruded coating layer 8 described later, the thermoplastic resin extruded and coated with the flat conductor 1 shrinks during the extrusion coating, so that the flat conductor 1 and the extruded coating layer 8 are in close contact even if they are not in an adhesive state. Because inflexibility is intact.

Moreover, since the adhesive bond layer is not interposed between the flat conductor 1 and the extrusion coating layer 8, peeling between them is suppressed. Furthermore, since the extrusion coating layer 8 can be continuously formed by the extrusion coating which will be described later with respect to the parallel conductor 1 arranged in parallel, a flat cable can be manufactured cheaply and expressway, In comparison, since the mutual spacing between the flat conductors 1 arranged in parallel can be narrowed, miniaturization of the flat cable can be realized.

Here, as a material of the flat conductor 1, oxygen free copper, phosphorus bronze, tough pitch copper, tin plating copper, nickel plating copper, etc. are mentioned as a preferable example. As a flat conductor, the thing cut | disconnected copper foil, the thing which rolled the conducting wire, etc. can be used suitably. In addition, you may mix the flat conductor 1 which differs in thickness and width according to the use of the flat cable to manufacture.

As a thermoplastic resin which comprises the said insulated resin layer 8, what has the bending elastic modulus 800-400 Mpa at the time of using it as a coating material, before performing extrusion coating mentioned later is used. Preferably the bending elastic modulus is 1000-2000 MPa.

When the extrusion coating layer 8 is formed by using a thermoplastic resin having a bending elastic modulus less than 800 MPa before extrusion coating, the extrusion coating layer 8 cannot flatly disperse the stress applied to the flat cable at the time of stretching, thereby obtaining the flat cable. When the flat conductor 1 is disconnected at an early stage and the extruded coating layer 8 is formed by using a thermoplastic resin having a bending elastic modulus before extrusion coating of more than 2400 MPa, the flat conductor 1 by stretching This is because cracking or the like occurs in the extruded coating layer 8 before the end of life, and the function as a flat cable cannot be maintained.

In addition, the bending elastic modulus referred to in the present invention refers to a value (value at a temperature of 23 ° C.) obtained by a regulation method specified in ASTM D790.

As a kind of such a thermoplastic resin, the following are mentioned as a preferable example.

First, it is a polyamide resin.

Polyamide-based resins are preferred as materials for increasing the repeated flexural life characteristics of flat cables because they have good self-lubricating properties and excellent wear resistance. In addition, the polyamide-based resin is preferably used when manufacturing flat cables for automobiles, because the natural frequency is small, the logarithmic damping rate is high, and thus the vibration can be absorbed and noise can be suppressed during operation of the flat cable. Do. In particular, it is preferable to use it for the flat cable for steering rotary connectors of automobiles. Moreover, polyamide resin is preferable because it can smoothly perform extrusion coating to the flat conductor 1, even if it raises the line speed of the manufacturing line mentioned later, and can manufacture the flat cable with the said characteristic favorable under high productivity.

As a polyamide resin, generally, it is a high molecular compound which has a peptide bond (-CONH-) as a repeating unit, Ring-opening polymers, such as (epsilon) -caprolactam and ω-laurolactam, hexamethylenediamine, and methac, depending on a polymerization type. Polycondensates of diamines such as silylenediamine, 2,4,4- or 2,2,4-trimethylhexamethylenediamine with dibasic acids such as adipic acid, sebacic acid, dodecanedioic acid and terephthalic acid, 11-aminoundecanoic acid And polycondensates of aminocarboxylic acids such as 12-aminododecanoic acid. These are generally called nylon, and examples thereof include nylon 6, nylon 66, nylon 610, nylon 12, nylon 11, nylon 46, nylon MXD · 6, nylon 6/66, nylon 106 and the like.

Among these, in addition to the above properties, nylon 12 is particularly excellent in the above-described polyamide-based resins, and has good adhesion with metals, and can ensure flexibility even at low temperatures, and hence its flexibility is not deteriorated. It is preferable to use it especially when manufacturing a flat cable for automobiles.

Next preferred thermoplastic resin in the extrusion coating layer 8 is a polyolefin resin. Since this polyolefin resin does not generally adhere to the flat conductor 1 except for a special one, a flat cable made of this resin is preferable in that the terminal processing can be easily performed.

As such a polyolefin resin, polypropylene, polyethylene, an ionomer, etc. are mentioned, for example. In addition to the above-mentioned characteristics, polypropylene has excellent extrusion processability and also has a small shrinkage difference in the longitudinal and transverse directions even in extrusion coating, so that a flat cable having a desired design dimension can be produced at a high yield and therefore inexpensively. desirable.

In addition, a polymer alloy having a sea island structure is also a preferred thermoplastic resin. By using polymer alloy, extrusion coating can be carried out smoothly even if the line speed of the production line is increased. Also, when the flat cable is stretched, island component is dispersed in sea component, so stress at the time of stretching This dispersion / attenuation yields very good repeated flexural life characteristics.

Such polymer alloys include, for example, ① polyamide-based resin as a sea component, polypropylene modified with epoxy or the like as a component, ② polypropylene as a sea component, and polyamide-based resin modified with an acid. Commercialized from polypropylene and made as a component, ③ made of ethylene / propylene copolymer as a sea component, made of polypropylene as a component, ④ ethylene-propylene block copolymer, ⑤ polyamide to modified polyphenylene ether Graft-polymerized resins, and? -Modified polyphenylene ethers and blends of polybutylene terephthalate.

The following polymer alloys based on polyamide-based resins and epoxy-modified polypropylenes in the above-described polymer alloys are preferable because they can improve the cyclic flexural life characteristics of flat cables. The polymer alloy will be described below.

This polymer alloy uses polyamide-based resin as a sea component and an epoxy-modified polypropylene described later as a island component. Here, as polyamide resin, the polyamide resin already illustrated as a preferable example of the thermoplastic resin used by this invention can be employ | adopted.

The epoxy modified polypropylene is synthesized by polymerizing a polypropylene polymer, an epoxy group-containing vinyl monomer, and an aromatic vinyl monomer in the presence of a radical initiator.

As a polypropylene polymer used for the synthesis | combination of the said epoxy-modified polypropylene, it is based on a propylene homopolymer or propylene, and it is a copolymer of another olefin monomer or ethylenic vinyl monomer, and content of polypropylene is 75 weight% The above is used. Specifically, isotactic polypropylene, a propylene-ethylene copolymer, a propylene-butene copolymer, etc. are mentioned. These may be used independently, or may mix and use two or more types, and may mix and use with another polymer, unless the property is impaired further.

Examples of the epoxy group-containing vinyl monomers include glycidyl methacrylate, glycidyl acrylate, allyl glycidyl ether and methacryl glycidyl ether, and these may be used alone or in combination of two or more. You may also In particular, glycidyl methacrylate is preferable.

It is preferable that the usage-amount of the epoxy-group-containing vinyl copolymer at the time of synthesis | combination shall be 10 weight part or less with respect to 100 weight part of usage-amounts of the said polypropylene polymer. This is because when the amount is more than 10 parts by weight, the obtained epoxy-modified polypropylene is not only low molecular weight, but also has high water absorption and deteriorates mechanical strength properties. Preferable usage-amount is 0.1-5 weight part with respect to 100 weight part of polypropylene-type polymers.

Aromatic vinyl monomers are used to improve the graft polymerization efficiency of epoxy group-containing vinyl monomers to propylene-based polymers and to improve compatibility of polyamide-based resins such as epoxy-modified polypropylenes and sea-components in polymer alloys of interest. Specific examples thereof include styrene, methyl styrene, vinyl toluene, vinyl xylene, ethyl vinyl benzene, isopropyl styrene, chloro styrene, dichloro styrene, bromostyrene and the like. These may be used independently, and may mix and use two or more types.

In order to prevent low molecular weight of the synthesized epoxy-modified polypropylene and to improve compatibility with the polyamide-based resin, the amount of the aromatic vinyl monomer is 50 parts by weight or less based on 100 parts by weight of the propylene-based polymer. It is preferable. In addition, it is preferable that the usage-amount of an aromatic vinyl monomer is the same quantity or more as the usage-amount of the said epoxy group containing vinyl monomer for the same reason. It is preferable that it is an amount of 1 to 5 times specifically ,.

Synthesis using the above components is carried out in the presence of a radical initiator using a mixing container such as an extruder or a closed container such as a Banberry mixer.

For example, when synthesizing with an extruder, a powder or pellet-like propylene polymer is fed to an extruder and heated to a temperature of 130 to 250 ° C. while being pressurized to melt it, and a radical initiator, an epoxy group-containing vinyl monomer, and an aromatic vinyl monomer are added thereto. After adding a fixed amount and mixing and kneading the polymerization reaction, the strands drawn from the die are cooled and pelletized by a pelletizer.

As a radical initiator, it is preferable to have the property which is easy to melt | dissolve in each said monomer, and the decomposition temperature exists in the range of 130-250 degreeC, For example, t-butyl per octet, bis (t-butyl peroxy) trimethyl cyclohexane, cyclohexa. Nonperoxide, benzoyl peroxide, dicumyl peroxide, t-butylperbenzoate, dimethyl-di (t-butylperoxy) hexane, dimethyl-di (t-butylperoxy) hexine and the like.

The radical initiator is usually used in an amount of 0.1 to 10 parts by weight, preferably 1 to 5 parts by weight based on 100 parts by weight of the total amount of the epoxy group-containing vinyl monomer and the aromatic vinyl monomer.

In addition, since the propylene polymer is a radically disintegratable polymer unlike an ethylene polymer, when melt heating is performed, the main chain is cut and the molecular weight is lowered. Thus, during the above-mentioned melt polymerization, the action of the epoxy group-containing vinyl monomer or the aromatic vinyl monomer is inhibited. It is preferable to add a stabilizer which is not added to the reaction system.

Examples of such stabilizers include hindered phenolic stabilizers, phosphorus stabilizers, metal soaps, antacid adsorbents such as magnesium oxide, hydrotalcite, and the like. These may be added independently and may add two or more types. The addition amount is usually 0.01 to 1 part by weight, preferably 0.05 to 0.5 part by weight based on 100 parts by weight of the propylene polymer.

The polymer alloy used for forming an extrusion coating layer by mixing the epoxy-modified polypropylene and polyamide resin synthesize | combined in this way is prepared. In particular, the use of nylon 6 as the polyamide-based resin is preferable because the stretchability of the flat cable is increased, and the extrusion coating of the flat conductor can be performed smoothly even if the line speed of the production line is increased.

At this time, the mixing ratio of both can be set to 5 to 50% by weight of epoxy-modified polypropylene, and thus 95 to 50% by weight of polyamide-based resin.

When the mixing ratio of the epoxy-modified polypropylene is less than 5% by weight, the effect of sufficiently dispersing the stress applied to the flat cable at the time of stretching is not exhibited, and the repeated bending life characteristics are insufficient, and when it is larger than 50% by weight, This is because the elongation and strength of the polymer alloy under high temperature are reduced and extrusion coating becomes difficult, which makes it difficult to obtain a flat cable having good dimensional accuracy.

In addition, you may mix | blend carbon, various flame retardants, glass fiber, antioxidant, etc. with resin used by this invention as needed.

This flat cable B1 can be manufactured by the production line shown in FIG.

In this production line, the plurality of flat conductors 1 are sent out from the bobbin 4 in a state where they are arranged in parallel at a predetermined interval, and pass through the crosshead 10 mounted on the extruder 9 to the flat conductors 1. Extrusion coating is performed, and the obtained flat cable (B1) is wound by the roll (7).

In the crosshead 10, the extruded needle pole 11 and the extrusion die 12 are arrange | positioned, as shown to FIG. 6 and FIG. The extruded needle poles 11 are provided with a plurality of needle poles 11a (four in the drawing) which are guides for parallelly arranging the flat conductors 1 to be sent at predetermined intervals, and are formed in the extrusion die 12. A die hole 12a for regulating the appearance of the extruded coating layer to be formed is formed.

The flat conductor 1 sent to the extruded needle pole 11 is arranged in parallel with the nipple hole 11a, and its surrounding space 12b (in the crosshead) in the process of passing between the extruded needle pole 11 and the die 12. The extrusion coating layer is formed in the flat conductor 1 by being coated with the thermoplastic molten resin supplied to and passing through the die hole 12a.

The thermoplastic resin used at this time is as above-mentioned. Although the molecular weight of these thermoplastic resins is not specifically limited, Usually, the relative viscosity ((eta)) is 0.5 or more, Preferably it is 2.0 or more, The formation of an extrusion coating layer can advance smoothly, and also the mechanical strength, such as the strength and extension | stretching of the formed extrusion coating layer, are carried out. It is preferable because the strength characteristics are improved, and thus the stretchability of the obtained flat cable is improved, and further, the dimensional accuracy can be improved.

At this time, the gap between the nipple hole 11a of the extruded needle pole 11 and the die hole 12a of the die 12 is set when the flat conductors arranged in parallel from the needle pole 11a enter the die hole 12a. These flat conductors 1 are set at intervals capable of micromoving in the width direction so as to be in a final arrangement state up to.

Moreover, it is preferable to adjust the shape and pressure inside the die 12 so that the pressure of the molten resin applied to the upper surface and lower surface of the flat conductor 1 sent from the nipple hole 11a may become the same. It is for preventing the thickness nonuniformity of the flat cable obtained, and making the thickness of the extrusion coating layer above and below the flat conductor 1 more uniform.

The total thickness of the flat cable obtained is determined by the shape and size of the extruded nipole 11 and the extruded die 12. Since the molten resin shrinks slightly after the extrusion coating, the shrinkage of the extruded nipole or the extruded die is considered. It is desirable to design dimensions and shapes.

Cooling of the flat cable B1 coming out of the crosshead 10 is performed so that the whole will not bend after cooling. For example, if the formed extrusion coating layer is thin, it may be left to cool in the air as it is. This is because the molten resin naturally solidifies the whole evenly during the cooling process. During this cooling, cooling with water, for example, causes a shrinkage difference between the outside and the inside of the molten resin, and the flat cable should be avoided because the entire cable is not curved to form a flat shape.

Usually, the thickness of the extrusion coating layer 8 which contact | connects the upper surface and lower surface of a flat conductor is set to 0.02-0.5 mm. If the thickness is thinner than 0.02 mm, the performance as an insulating layer will not be sufficient, and if it is thicker than 0.5 mm, the flat cable itself will not bend well, and the function as a flat cable will be degraded. Cracking occurs and the extensible property deteriorates.

And at the time point where the extrusion coating layer solidified to some extent by air cooling, you may auxiliary water bath or hot water bath, and may finally adjust the temperature wound by a roll.

In the manufacturing line shown in FIG. 5, a preheating device may be fitted between the bobbin 4 and the crosshead 10 to preheat the flat conductor 1 and then be sent to the crosshead 10.

Although the preheating temperature at that time is selected from the relationship of resin to be used, it is normally set in the temperature range of 100-350 degreeC, especially 120-280 degreeC.

As the preheater, a gas heating device, a commercially available conductor heating device, or a high frequency induction heating device can be used.

The flat conductor 1 may be introduced into the crosshead 10 without preheating. The crosshead 10 may be introduced into the crosshead 10 by warming it to a temperature not exceeding the temperature of the resin supplied to the crosshead 10. According to these methods, the shape stability of a flat cable can be improved.

If the silane coupling agent is applied to the surface of the flat conductor prior to the extrusion coating on the flat conductor, the mutual adhesion between the flat conductor and the extruded coating layer is improved, and the stretchability of the flat cable can be improved.

Examples of the silane coupling agent to be used include those having at least one functional group selected from the group of an epoxy group, a methacryloxy group, an amino group, a chlor group and a mercapto group and a hydrolyzable group such as an alkoxy group such as a methoxy group and an ethoxy group. Can be.

Specifically, epoxy-based things, such as 3-glycidoxy propyl trimethoxysilane and 2- (3, 4- epoxycyclohexyl) ethyl trimethoxysilane; Methacryloxy compounds such as 3-methacryloxypropyltrimethoxysilane; 3-aminopropyltriethoxysilane, 3-aminopropylmethyldimethoxysilane, N- (2-aminoethyl) 3-aminopropyltriethoxysilane, N- (2-aminoethyl) 3-aminopropylmethyldimethoxy Amino-based ones such as silanes; Chlor-based ones such as 3-chloropropyltrimethoxysilane; Mercapto-based ones such as 3-mercaptopropyltrimethoxysilane; Can be mentioned.

As a coating method, a silane coupling agent may be diluted with solvents, such as water, methanol, ethanol, and toluene, and what is necessary is just to apply | coat or immerse the obtained solution using a brush or an application roll, and to dry it.

8 shows another flat cable B2.

This flat cable B2 is formed with the extrusion coating layer 13 further outside the extrusion coating layer 8 of the flat cable B1.

The extruded coating layer 13 may be made of the same material as the extruded coating layer 8, and may be, for example, polyvinyl chloride, polyethylene, polystyrene, polycarbonate, polyethylene terephthalate, polyacetal, polybutylene terephthalate, or modified polyphenyl. It may be comprised from other materials, such as a lene ether, a fluororesin, and rubber. In addition, the extrusion coating layer 13 is not limited to covering the entire circumference of the extrusion coating layer 8, and may cover a part of one side or both ends of the cable.

In the case of this type of flat cable, by appropriately selecting the material of the extruded coating layer 13, it is possible to bend more greatly and to improve the stretchability.

In the case of this type of flat cable, as shown in Fig. 8, the extrusion coating layer is not limited to a two-layer structure, and may be formed in a larger number of layers, but the extrusion coating layer 8 directly covering the flat conductor 1 (8). ) Is required to be composed of the above-mentioned thermoplastic resin.

9 shows another flat cable B3.

The flat cable B3 is thin in the thickness of the extruded coating layer 8 between the flat conductors 1 arranged in parallel and at both ends.

The flat cable B3 may be manufactured in the die 12 shown in Figs. 6 and 7 by making the shape of the die hole 12a the same as that of the cable B3 shown in Fig. 9, for example. The amount of extrusion of the molten resin into the inner space 12b of the crosshead 10 on which the extruded dice 12 and the extruded needle 11 shown in FIGS. 6 and 7 are arranged is adjusted, and the natural shrinkage of the molten resin is adjusted. It can also manufacture by.

In addition, in the flat cable of the present invention described above, in general, when the thickness of the flat conductor 1 becomes thick, the flexibility of the flat cable becomes worse, and as the thickness of the flat conductor 1 becomes thinner, the flexibility of the flat cable manufactured becomes It becomes good. However, if it is made too thin, handling becomes difficult, specifically, extrusion coating becomes difficult, and the mass productivity as a flat conductor also falls.

From such a thing, it is preferable that the thickness of the flat conductor to be used is 0.02-0.5 mm, and it is especially preferable that it is 0.03-0.2 mm. Moreover, although the width | variety of the flat conductor 1 is suitably determined by relationship with the objective use of a flat cable, it is about 0.9-4 mm normally.

Moreover, it is preferable that the thickness of the upper surface part 8a and the lower surface part 8b in the extrusion coating layer located above and below the flat conductor 1 is 0.02-0.5 mm, respectively. When the thickness is thinner than 0.02 mm, extrusion coating is difficult and reliability as the insulating layer is lowered. When the thickness is thicker than 0.5 mm, the bending property is remarkably lowered and the function as a flat cable is lost. As for the thickness of the extrusion coating layers 8a and 8b, it is more preferable that they are 0.030-0.2 mm.

Examples 1-4 and Comparative Examples 1-4

(1) A flat cable was manufactured as follows with the production line shown in FIG.

First, four flat conductors 1 of a tough pitch copper having a width of 1.0 mm and a thickness of 140 µm are sent out in parallel from the bobbins 4 in parallel, and the gaps of each other are aligned at 1.0 mm with guides (not shown), without preheating them. It was sent continuously to the crosshead (10).

The mutual spacing of the nipple holes 11a of the extruded nipples 11 in the crosshead 10 is 1.0 mm.

Nylon 12 (Diamide L2140, manufactured by Daicel Hums Co., Ltd., bending modulus 1200 MPa under measurement conditions of 23 ° C. and 50% relative temperature) was supplied to the crosshead 10 at a temperature of 240 ° C. Extrusion coating was carried out and air cooled. The line speed at this time is shown in Table 1.

The flat cable B3 of the cross-sectional structure shown in FIG. 9 was obtained continuously. And in the formed extrusion coating layer 8, the thickness of the upper surface part 8a and the lower surface part 8b was 0.08 mm, and the thickness in the center part between flat conductors was 0.23 mm. In addition, the width of the obtained flat cable (B3) was 9 mm. Let the obtained flat cable be Example 1.

The resin used to form the extruded coating layer 8 was polypropylene (2038, Chisopolypro manufactured by Chisso Co., Ltd., bending modulus of 1270 MPa), except that the temperature of the resin supplied to the crosshead was 210 ° C. A flat cable was manufactured in the same manner as in Example 1. Let the obtained flat cable be Example 2.

A flat cable was produced in the same manner as in Example 2 except that the resin used for forming the extruded coating layer 8 was polypropylene (2527 of Chixopolyprop from Chiso Co., Ltd., bending modulus 1960 MPa). Let the obtained flat cable be Example 3.

93% by weight of polypropylene, 2% by weight of glycidyl methacrylate, 5% by weight of styrene were mixed and stabilized by Chiba Chemical Co., Ltd .: 0.05% by weight of Iganox 1010, 0.05% by weight of phosphite 168 from the company and 0.1% by weight of calcium stearate as a stabilizer was added, and 30% by weight of pellets of epoxy-modified polypropylene obtained by synthesis in the presence of 0.2% by weight of dimethyldi (t-butylperoxy) hexine and Ubenoyl 1013NU2 (trade name, Ubegosan ( Note) Manufacture) Flat cable was prepared in the same manner as in Example 1 except that 70% by weight of the mixture was mixed and the mixture was fed to the crosshead at a temperature of 260 ° C. Let the obtained flat cable be Example 4.

And the bending elastic modulus of the said mixture was 1640 Mpa (measured value on condition of 23 degreeC of temperature, 50% of relative temperature).

The resin used to form the extruded coating layer 8 was a polymer alloy of polystyrene and polyphenylene ether (Zyron 540Z, manufactured by Asahi Kasei Co., Ltd., bending modulus of 2450 MPa), and the temperature of the resin supplied to the crosshead was A flat cable was manufactured in the same manner as in Example 1 except that it was 270 ° C. Let obtained flat cable be the comparative example 1.

The resin used to form the extruded coating layer 8 was a high-density polyethylene (J-REX-HD-C3502E manufactured by Nippon Polyolefin Co., Ltd., bending modulus of 780 MPa), and the temperature of the resin supplied to the crosshead was 210 ° C. A flat cable was manufactured in the same manner as in Example 1 except for the following. Let the obtained flat cable be the comparative example 2.

(2) A flat cable was manufactured as follows with the production line shown in FIG.

From the bobbin 4, four flat conductors 1 of tough pitch copper having a width of 1.0 mm and a thickness of 140 µm were sent out in parallel, and the gaps were arranged at 1.0 mm with guides (not shown) to heat the rolls 6a and 6b. )

At this time, the polyethylene terephthalate films 3a, 3b having a thickness of 38 μm, on which the polyester films 2, 2 having a thickness of 47 μm are laminated, are supplied from the rolls 5a, 5b, and the flat conductor ( It adhere | attached on the upper surface and lower surface of 1), and sent it to the heating rolls 6a and 6b, and the whole was heat-compression-bonded on the conditions of the surface temperature of a heating roll at 150 degreeC, and roll surface pressure 5 kg / cm <2>. The line speed at this time is shown in Table 1.

A flat cable having the cross-sectional structure shown in FIG. 1 and having a total thickness of 0.31 mm and a width of 9 mm was obtained. Let this be the prior art example 1.

(3) A flat cable was manufactured as follows with the production line shown in FIG.

That is, the heating rolls 6c and 6d disposed at the rear ends of the heating rolls 6a and 6b were operated under the condition of a surface temperature of 120 ° C. and a roll surface pressure of 5 kg / cm 2, and the line speeds as shown in Table 1 below. Operation was carried out under the same conditions as in the case of the conventional example 1 except that it was increased. Let the obtained flat cable be the prior art example 2.

About the above 8 types of flat cables, the service life at the time of repeated bending was measured by the following specification.

That is, each flat cable is cut into 400 mm in length to make a sample, the sample is wired in a U shape with a bending diameter of 10 mm, one end is fixed, and the other end is reciprocated for 100 minutes at a stroke of 200 mm for 100 minutes. The flexural motion was performed to measure the number of round trips until the first electrical disconnection (including instantaneous disconnection) occurred in the flat conductor. The larger this value is, the longer the service life of the flat cable is. The above result was shown in Table 1.

Bending Elastic Modulus of Used Resin (MPa) Line speed (m / min) Round trip number of exercise Example 1 Example 2 Example 3 Example 4 1200127019601640 50505050 180000160000410000820000 Comparative Example 1 Comparative Example 2 2450780 5050 4000060000 Conventional Example 1 Conventional Example 2 - 23 3000050000

The following are clear from Table 1.

(1) Regarding the production of the flat cables of Examples 1 to 4, the production line speed can be increased to 50 m / min. Moreover, the obtained flat cable showed the very excellent flexural property.

However, in the case of a comparative example, all have remarkably lower extrudability than Examples 1-4.

This is because the bending elastic modulus of the resin constituting the extrusion coating layer deviates from 800 to 2400 MPa in the case of each comparative example.

For example, as can be clearly seen in comparison with Example 4 and Comparative Example 1, even if all of the constituent resin of the extrusion coating layer is a polymer alloy, in the case of Comparative Example 1 is a polymer alloy having a bending elastic modulus exceeding 2400 MPa Elongation is falling considerably. From this, it is understood that the constituent resin of the extruded coating layer should use a bending elastic modulus of 800 to 2400 MPa.

(2) On the other hand, both of the conventional examples 1 and 2 can raise the line speed only to about 2 to 3 m / min, and further, the stretchability of the obtained flat cable has a low value. That is, productivity is very low compared with the Example, and the obtained flat cable is inferior in stretchability.

Examples 5-8

When manufacturing the flat cable of Example 1, the flat cable was manufactured by varying the thickness of the flat conductor used, the thickness of the upper and lower surfaces of the extruded coating layer to be formed, and the line speed as shown in Table 2, Flexibility was investigated. The results are shown in Table 2.

As can be clearly seen from Table 2, even if the thickness of the flat conductor is 0.25 mm and thick, the extrudability decreases as compared with that of the other examples even when the extruded layer is supplemented by thickening the extruded coating layer.

The flat cable of the present invention is very excellent in the life characteristics during repeated bending. In addition, according to the manufacturing method of the present invention, the line speed can be increased by 10 times or more as compared with the case of the conventional production line, and it is possible to manufacture the above-mentioned useful flat cable at a very high productivity at low cost.

The flat cable of the present invention is for use in which vigorous repetitive flexing motions are forced, such as various communication devices, home appliances, copying machines, computers, printers, image scanners, word processors, CD players, steering wheel connectors of automobiles, and other automobiles. As a cable used for wiring, the industrial value is very large. It can also be used for automotive wires and harnesses.

Claims (10)

Flat cable consisting of: The plurality of flat conductors arranged in parallel are embedded in the insulating resin layer; And, At least the insulating resin layer in contact with the flat conductor is an extrusion coating layer made of a thermoplastic resin having a bending modulus of 800 to 2400 MPa. The flat cable according to claim 1, wherein the thermoplastic resin is a polyamide resin. The flat cable according to claim 2, wherein the polyamide-based resin is nylon 12. The flat cable according to claim 1, wherein the thermoplastic resin is a polyolefin resin. The flat cable according to claim 4, wherein the polyolefin resin is polypropylene. The flat cable according to claim 1, wherein the thermoplastic resin is a polymer alloy. The flat cable according to claim 6, wherein the polymer alloy is an island-in-water polymer alloy based on polyamide-based resin and epoxy-modified propylene. The flat cable according to claim 7, wherein the mixing ratio of the polyamide-based resin is 50 to 95% by weight. The flat cable of Claim 1 whose thickness of a flat conductor is 0.02-0.5 mm, and the thickness in the part in which the said flat conductor of the said insulated resin layer exists is 0.02-0.5 mm. Method for producing a flat cable consisting of: A plurality of flat conductors are arranged in parallel and sent to the crosshead of the extruder; And A thermoplastic resin having a bending modulus of 800 to 2400 MPa is supplied to the crosshead to extrude the flat conductor.