JP2012031533A - Stranded wire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stranded wire that can sufficiently exert an effect of forming a resin film for a long period, has a high durability and is excellent in reliability.SOLUTION: A stranded wire 1 is provided with a resin film 4 formed on at least outer peripheral surface side. The resin film 4 is mainly composed of a polyvinyl butyral resin which has a butyralation degree of 40-85 mol% and whose content of hydroxy group in a molecule is regulated within a range of 11-27 wt.%.

Description

  The present invention relates to a stranded wire such as a PC stranded wire or a metal wire, and more particularly to a stranded wire having a resin film formed on the outer peripheral surface thereof.

  Various twisted wires in which a resin film is formed on the peripheral surface side of a twisted wire such as a PC twisted wire or a metal wire for the purpose of corrosion prevention of the twisted wire have been proposed as shown in the following patent documents.

  These patent documents describe the use of various materials such as an epoxy resin, a polyethylene resin, a polyester resin, and a polyvinyl chloride resin as a synthetic resin used for forming the resin film.

JP-A-6-322679 JP-A-7-90786 JP 2003-62523 A JP 2007-319770 A JP 2007-32259 A JP 2007-32269 A

  However, in the stranded wire having the resin coating formed of the material as described above, the hardness of the resin coating is low, the pulling strength from the concrete is weak, the weather resistance of the resin coating is poor, or the stranded wire is wound up. If left untreated, the resin film will crack or the resin film will peel off from the surface of the stranded wire, and the effect of forming the resin film on the peripheral surface side of the stranded wire will be sufficient for a long period of time. There is a problem that it cannot be demonstrated.

  An object of the present invention is to provide a highly durable stranded wire excellent in reliability, which can overcome such drawbacks of the prior art and sufficiently exhibit the effect of forming a resin film over a long period of time.

In order to achieve the above object, the first means of the present invention is a stranded wire having a resin film formed at least on the outer peripheral surface side.
The resin film is a resin film mainly composed of a polyvinyl butyral resin having a butyralization degree of 40 to 85 mol% and a hydroxyl group content in the molecule of 11 to 27% by weight. It is a feature.

In order to achieve the above object, the second means of the present invention is a stranded wire in which a resin film is formed at least on the outer peripheral surface side.
The resin film is a resin film mainly composed of a polyvinyl butyral resin having a butyralization degree of 40 to 85 mol% and a hydroxyl group content in the molecule of 11 to 27% by weight,
It is characterized by having inorganic coarse particles fixed by the resin film and forming innumerable protrusions protruding from the surface of the resin film.

According to a third means of the present invention, in the first or second means,
The said resin film contains the organic antioxidant which has the following molecular structural formula of 5 weight% or less with respect to the said polyvinyl butyral resin.

In the formula, R1 to R8: a linear or branched alkyl group having 1 to 4 carbon atoms or hydrogen,
l, m, n: each an integer of 1 to 10,
X: N or O heteroatom.

  The present invention is configured as described above, and the effect of forming the resin film can be sufficiently exhibited over a long period of time, and a highly durable stranded wire excellent in reliability can be provided.

It is an expanded sectional view of the strand wire concerning the 1st example of the present invention. It is an expanded sectional view of the strand wire which concerns on 2nd Example of this invention. It is an expanded sectional view of the strand wire concerning the 3rd example of the present invention. It is an expanded sectional view of the strand wire which concerns on 4th Example of this invention. It is an expanded sectional view of the strand wire which concerns on 5th Example of this invention. It is an expanded sectional view of the strand wire which concerns on 6th Example of this invention. It is the further principal part expanded sectional view of the strand wire which concerns on the 4th-6th Example of this invention. It is a side view of the strand wire which concerns on the 4th-6th Example of this invention. It is a schematic block diagram of the whole processing apparatus which manufactures the strand wire which concerns on 5th Example of this invention. It is a schematic block diagram of the electrostatic fluid immersion apparatus used in the Example of this invention. It is sectional drawing of the coarse particle spraying part in the coarse particle spraying apparatus used in the Example of this invention.

Next, each embodiment of the present invention will be described with reference to the drawings.
(Structure of stranded wire)
First, the structure of the strand wire which concerns on the Example of this invention is demonstrated. FIG. 1 thru | or 6 is an expanded sectional view of the strand wire which concerns on each Example of this invention.

  The stranded wire 1 according to the first embodiment shown in FIG. 1 is composed of one central strand 2 and six outer peripheral strands 3 arranged around the central strand 2. The outer peripheral surfaces of the central strand 2 and the outer peripheral strand 3 are individually covered with a resin coating 4, and the twist shown in FIG. 1 is obtained by twisting the central strand 2 and the outer peripheral strand 3 with each other. Line 1 is obtained.

  Therefore, in the case of this stranded wire 1, a plurality of voids 5 are formed inside, and the strands 2 and 3 are not constrained.

  The stranded wire 1 according to the second embodiment shown in FIG. 2 is composed of one central strand 2 and six outer peripheral strands 3 arranged around the central strand 2. Instead of individually covering the outer peripheral surfaces of the strands 2 and 3 with the resin coating 4 as in the stranded wire 1 according to the first embodiment, a continuous resin coating 4 is formed on the entire outer peripheral surface of the stranded wire 1. ing. Also in the case of the stranded wire 1 according to this embodiment, a plurality of voids 5 are formed inside the stranded wire 1.

  The stranded wire 1 according to the third embodiment shown in FIG. 3 is formed with a continuous resin film 4 on the outer peripheral surface thereof, and is the same as the resin film 4 in the internal gap 5 (see FIG. 2) of the stranded wire 1. Filled with resin.

  Therefore, in the case of the stranded wire 1 according to this embodiment, the outer peripheral surface of the stranded wire 1 is covered and connected by the continuous resin coating 4, and the inside of the stranded wire 1 is connected by the filling resin layer 6. The whole is solid integrated.

  In the stranded wire 1 according to the fourth embodiment shown in FIG. 4, the difference from the stranded wire 1 shown in FIG. 1 is that the resin coating 4 formed on the strands 2 and 3 contains inorganic coarse particles 7. It is a point.

  As shown in FIG. 4, since some of the inorganic coarse particles 7 protrude from the surface of the resin coating 4, each strand 2 when the strands 2 and 3 are twisted to produce a strand 1. , 3, and 3, the protruding portion of the inorganic coarse particles 7 protruding from the surface of the resin coating 4 bites into the resin coating 4 of the adjacent strands 2 and 3, and the resin is passed through countless inorganic coarse particles 7. The coatings 4 are connected.

  In the stranded wire 1 according to the fifth embodiment shown in FIG. 5, the difference from the stranded wire 1 shown in FIG. 2 is that the resin coating 4 formed on the outer peripheral surface of the stranded wire 1 contains inorganic coarse particles 7. It is a point.

  In the stranded wire 1 according to the sixth embodiment shown in FIG. 6, the difference from the stranded wire 1 shown in FIG. 3 is that the resin coating 4 formed on the outer peripheral surface of the stranded wire 1 contains inorganic coarse particles 7. It is a point.

  FIG. 7 is a further enlarged cross-sectional view of the main part in the vicinity of the resin coating 4 of the wires 2 and 3 in the fourth to sixth embodiments. As shown in the figure, the inorganic coarse particles 7 are embedded in the resin film 4, but some of them protrude from the resin film 4 and have innumerable protrusions 8.

  FIG. 8 is a side view of the stranded wire 1 according to the fourth to sixth embodiments. As shown in the figure, a resin coating 4 containing inorganic coarse particles 7 is provided on the outer peripheral surface of the stranded wire 1, and innumerable irregularities are formed on the surface.

(Composition of resin film)
In each of the embodiments described above, the resin coating 4 is made of a material mainly composed of polyvinyl butyral resin (hereinafter abbreviated as PVB resin).

  The PVB resin is a polymer compound having a three-dimensional structure obtained by condensing polyvinyl alcohol and an aldehyde using an acid catalyst such as hydrochloric acid, sulfuric acid or nitric acid. As the aldehyde, an aldehyde having 2 to 6 carbon atoms is preferable, and n-butyraldehyde is particularly preferable among them.

  This PVB resin-based coating has a hydroxyl group in its molecule, so it has good adhesion to metals and inorganic coarse particles, and does not deteriorate even when exposed to the outdoors for a long period of time. In addition, it has a feature that it can sufficiently withstand the alkalinity of concrete.

  The degree of butyralization of the PVB resin is 40 to 85 mol%, preferably 50 to 85 mol%. When the degree of butyralization is in the above-described range, the resin coating 4 having excellent fluidity, uniform film thickness, and no pinholes can be formed. The content of vinyl ester units is 0.1 to 30 mol%, the content of vinyl alcohol units is 10 to 50 mol%, the degree of polymerization is 200 to 1700, preferably 250 to 1000, and the acid value is 0.7 mgKOH / g or less. It is.

  The content of hydroxyl groups in the PVB resin molecule is 11 to 27% by weight, preferably 18 to 27% by weight, and more preferably 18 to 21% by weight. If the hydroxyl group content in the molecule is less than 11% by weight, the hydroxyl group content is originally low, so that the adhesive strength to the strands is insufficient, while the hydroxyl group content in the molecule exceeds 27% by weight. Water absorption results in a decrease in adhesive strength. Therefore, by regulating the hydroxyl group content in the molecule to a range of 11 to 27% by weight, the adhesive strength with the strands is strong and a high anticorrosive effect is exhibited over a long period of time.

  The PVB resin is preferably in the form of aggregated particles of primary particles. The average particle size of the primary particles is 5 μm or less, and the maximum particle size is 10 μm or less. The average particle size of the aggregated particles is 150 μm or less, and the maximum particle size is 250 μm or less. The average particle size of the aggregated particles is preferably 130 μm or less, and more preferably 100 μm or less. In addition, a primary particle is a particle | grains produced | generated initially in the acetalization reaction of polyvinyl alcohol here.

  The powder coating having such a particle diameter has excellent fluidity, can form a resin film 4 having a uniform film thickness and no pinholes, has high adhesive strength with the wires 2 and 3, and has a high anticorrosive effect. .

  An antioxidant is added in the range of 0.02 to 5% by weight with respect to the PVB resin. When the content of the antioxidant is less than 0.02% by weight, the effect of the antioxidant is not sufficiently exhibited and the flex resistance of the resin coating 4 is not sufficient. On the other hand, if the content of the antioxidant is more than 5% by weight, pinholes are generated in the resin coating 4 or the adhesive strength of the resin coating 4 to the strands 2 and 3 tends to decrease.

  The molecular weight of the antioxidant is 380 to 1000, preferably 400 to 800, and more preferably 600 to 800. If an antioxidant having a molecular weight of 380 or more is used, the bending resistance of the resin coating 4 is further improved, the resin coating 4 is not easily peeled off or cracked with respect to the wires 2 and 3, and the fluidity when the resin is melted. Can be formed, and the resin film 4 without pinholes can be formed. When the molecular weight exceeds 1000, the compatibility with the PVB resin is lowered, and it becomes difficult to form a good resin film 4.

  The melting point of the antioxidant is 80 to 230 ° C, preferably 90 to 180 ° C. When having such a melting point, dry blending with PVB resin powder is possible.

Specifically, an organic compound having the following molecular structural formula is preferable as the antioxidant.

In the formula, R1 to R8: a linear or branched alkyl group having 1 to 4 carbon atoms or hydrogen,
l, m, n: each an integer of 1 to 10,
X: N or O heteroatom.

  Examples of the linear or branched alkyl group having 1 to 4 carbon atoms include methyl, ethyl, propyl, i-propyl, n-propyl, i-butyl, n-butyl, and t-butyl.

Specific examples of the antioxidant include, for example, hexamethylenebis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate],
O 3,9-bis {1,1-dimethyl-2- [β- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy] ethyl} 2,4,8,10-tetraoxaspiro [5,5] -undecane,
O N, N'-hexane-1,6-diylbis [3- (3,5-di-t-butyl-4-hydroxyphenylpropionamide)],
1,3,5-tris (4-t-butyl-3-hydroxy-2,6-xylylmethyl) -1,3,5-tridiamine-2,4,6- (1H, 3H, 5H) -trione,
2,6-di-t-butyl-4- [4,6-bis (octylthio) -1,3,5-triazinylamino] phenol,
1,3,5-tris (3,5-di-t-butyl-4-hydroxybenzyl) -1,3,5-tridiamine-2,4,6- (1H, 3H, 5H) -trione,
○ 4,4'-Butyldenbis (6-t-butyl-3-methylphenol)
And so on.

  In addition to this antioxidant, other antioxidants or phosphorus heat stabilizers, hydroxylamine heat stabilizers, sulfur heat stabilizers and the like can be used in combination.

  As the inorganic coarse particles 7, for example, one kind or a mixture of two or more kinds selected from alumina, ceramic, silica sand, glass, iron, stainless steel and the like are used. The average particle diameter of the inorganic coarse particles 7 used is 50 μm to 1 mm, preferably 100 μm to 1 mm.

(Manufacturing process of stranded wire)
Next, an example of a manufacturing process of the stranded wire according to each of the above embodiments will be described.

○ Manufacturing process example of stranded wire according to the first embodiment (a) Wire → resin powder coating → heating and melting → cooling → twisting wire processing.
Resin powder is applied to the surfaces of the strands 2 and 3, heated and melted and cooled to form a resin coating 4 on the surfaces of the strands 2 and 3, and then twisted by twisting. Line 1 is assumed.

(B) Wire → resin melt application → cooling → twist wire processing.
By passing the strands 2 and 3 through the resin heating and melting tank, the surface of the strands 2 and 3 is applied by applying the resin melt to the surfaces of the strands 2 and 3 and cooling it. A resin coating 4 is formed on the substrate, and then a stranded wire process is performed to obtain a stranded wire 1.

(C) Twisted wire → twisting process → resin powder application → heating and melting → cooling → twisting process.
The strands 2 and 3 are separated by twisting back the strands, and resin powder is applied to the surfaces of the strands 2 and 3. By heating and melting it and cooling it, the resin film 4 is formed on the surfaces of the strands 2 and 3, and then twisted wire processing is performed to obtain a twisted wire 1 again.

(D) Twisted wire → twisting process → resin melt application → cooling → twisting process.
The strands 2 and 3 are separated by untwisting the stranded wires, and the strands 2 and 3 are passed through a resin heating and melting tank to heat and melt the resin on the surfaces of the strands 2 and 3. By applying an object and cooling it, a resin coating 4 is formed on the surfaces of the strands 2 and 3, and then a stranded wire process is performed to obtain a stranded wire 1 again.

○ Example of manufacturing process of stranded wire according to second embodiment (e) Twisted wire → coating outer peripheral resin powder → heating and melting → cooling.
A resin film 4 is formed on the outer peripheral surface of the stranded wire 1 by applying an outer peripheral resin powder coating on the outer peripheral surface of the stranded wire 1, heating and melting it, and cooling it.

(F) Stranded wire → Application of outer peripheral resin melt → Cooling.
The resin film 4 is applied to the outer peripheral surface of the stranded wire 1 by passing the stranded wire 1 through the heat melting tank of the resin, applying the heated melt of the resin to the outer peripheral surface of the stranded wire 1 and cooling it. Form.

Example of manufacturing process of twisted wire according to third embodiment (g) Wire → resin powder coating → heating and melting → cooling → twisting wire processing → peripheral resin powder coating → heating melting → cooling.
Resin powder is applied to the surfaces of the strands 2 and 3, heated and melted and cooled to form a resin coating 4 on the surfaces of the strands 2 and 3, and then twisted by twisting. Line 1 is assumed.

  The outer peripheral resin powder is applied to the outer peripheral surface of the stranded wire 1 with the resin coating 4 and heated to melt the resin coating 4 and the outer peripheral resin powder previously on the outer peripheral surface of the stranded wire 1. By cooling, a thick resin coating 4 is formed on the outer peripheral surface of the stranded wire 1.

  Also, by heating and cooling after the application of the outer peripheral resin powder, the resin coating 4 formed inside the stranded wire 1 is melted to fill the gap between the strands 2 and 3, thereby forming the filled resin layer 6.

(H) Twisted wire → twisting processing → resin powder coating → heating and melting → cooling → twisting wire processing → peripheral resin powder coating → heating melting → cooling.
The strands 2 and 3 are separated by twisting back the strands, and resin powder is applied to the surfaces of the strands 2 and 3. By heating and melting it and cooling it, the resin film 4 is formed on the surfaces of the strands 2 and 3, and then twisted wire processing is performed to obtain a twisted wire 1 again.

  The outer peripheral resin powder is applied to the outer peripheral surface of the stranded wire 1 with the resin coating 4 and heated to melt the resin coating 4 and the outer peripheral resin powder previously on the outer peripheral surface of the stranded wire 1. By cooling, a thick resin coating 4 is formed on the outer peripheral surface of the stranded wire 1.

  Also, by heating and cooling after the application of the outer peripheral resin powder, the resin coating 4 formed inside the stranded wire 1 is melted to fill the gap between the strands 2 and 3, thereby forming the filled resin layer 6.

(I) Twisted wire → heating → extruding resin film and filled resin layer → cooling.
The stranded wire 1 is heated and passed through the crosshead part of the extruder. Since this crosshead part is supplied with a high-temperature resin melt,
While the gap 5 between the strands 2 and 3 is filled with the molten resin, the molten resin is also supplied to the outer peripheral portion of the stranded wire 1 and cooled, so that the thick resin film 4 is formed on the outer periphery of the stranded wire 1. As it is formed, a filling resin layer 6 is formed inside the stranded wire 1.

Example of manufacturing process of stranded wire according to the fourth embodiment (j) Wire → resin powder application → heat melting → inorganic coarse particle spraying → cooling → twisted wire processing.
Resin powder is applied to the surfaces of the strands 2 and 3, heated and melted, and the inorganic coarse particles 7 are sprayed and cooled when the resin coating is kept in a molten state, whereby the strands 2 and 3 The resin film 4 containing the inorganic coarse particles 7 is formed on the surface of the film, and then the stranded wire is processed to obtain the stranded wire 1.

(K) Elementary wire → resin melt application → inorganic coarse particle spraying → cooling → twisted wire processing.
By passing the strands 2 and 3 through the resin heating and melting tank, the resin melt is applied to the surface of the strands 2 and 3, and the inorganic coarse particles are kept in a molten state. By spraying 7 and cooling, the resin coating 4 containing the inorganic coarse particles 7 is formed on the surfaces of the strands 2 and 3, and then a stranded wire process is performed to obtain a stranded wire 1.

(L) Twisted wire → twisting processing → resin powder coating → heating and melting → inorganic coarse particle spraying → cooling → twisting wire processing.
The strands 2 and 3 are separated by twisting back the strands, and resin powder is applied to the surfaces of the strands 2 and 3. By heating and melting it and spraying and cooling inorganic coarse particles 7 when the resin film is kept in a molten state, a resin film 4 containing inorganic coarse particles 7 is formed on the surfaces of the wires 2 and 3. Then, stranded wire processing is performed to obtain a stranded wire 1 again.

(M) Twisted wire → twisting processing → resin melt application → inorganic coarse particle spraying → cooling → twisting wire processing.
The strands 2 and 3 are separated by untwisting the stranded wires, and the strands 2 and 3 are passed through a resin heating and melting tank to heat and melt the resin on the surfaces of the strands 2 and 3. The resin coating 4 containing the inorganic coarse particles 7 is formed on the surfaces of the strands 2 and 3 by spraying the inorganic coarse particles 7 and cooling them when the resin coating is kept in a molten state. Then, stranded wire processing is performed to obtain a stranded wire 1 again.

Example of manufacturing process of stranded wire according to fifth embodiment (n) Twisted wire → outer peripheral resin powder application → heat melting → inorganic coarse particle spraying → cooling.
By applying an outer peripheral resin powder coating on the outer peripheral surface of the stranded wire 1, heating and melting it, and spraying and cooling the inorganic coarse particles 7 when the resin coating is kept in a molten state, the stranded wire 1 A resin coating 4 containing inorganic coarse particles 7 is formed on the outer peripheral surface.

(O) Stranded wire → Application of outer peripheral resin melt → Spraying inorganic coarse particles → Cooling.
By passing the stranded wire 1 through the resin heat melting tank, the resin heat melt is applied to the outer peripheral surface of the stranded wire 1, and the inorganic coarse particles 7 are blown when the resin film is kept in a molten state. By attaching and cooling, the resin film 4 including the inorganic coarse particles 7 is formed on the outer peripheral surface of the stranded wire 1.

Example of manufacturing process of stranded wire according to sixth embodiment (p) Wire → resin powder coating → heat melting → cooling → twisting wire processing → peripheral resin powder coating → heating melting → inorganic coarse particle spraying → cooling.
Resin powder is applied to the surfaces of the strands 2 and 3, heated and melted and cooled to form a resin coating 4 on the surfaces of the strands 2 and 3, and then twisted by twisting. Line 1 is assumed.

  The outer peripheral resin powder is applied to the outer peripheral surface of the stranded wire 1 with the resin coating 4, and the resin coating 4 and the outer peripheral resin powder previously on the outer peripheral surface of the stranded wire 1 are integrally melted by heating and melting it. .

  By spraying the inorganic coarse particles 7 while cooling the resin coating and cooling it, a thick resin coating 4 containing the inorganic coarse particles 7 is formed on the outer peripheral surface of the stranded wire 1.

  Also, by heating and cooling after the application of the outer peripheral resin powder, the resin coating 4 formed inside the stranded wire 1 is melted to fill the gap between the strands 2 and 3, thereby forming the filled resin layer 6.

(Q) Twisted wire → twisting processing → resin powder coating → heating and melting → cooling → twisting wire processing → peripheral resin powder coating → heating melting → injection of inorganic coarse particles → cooling.
The strands 2 and 3 are separated by twisting back the strands, and resin powder is applied to the surfaces of the strands 2 and 3. By heating and melting it and cooling it, the resin coating 4 is formed on the surfaces of the strands 2 and 3, and then twisted wire processing is performed to obtain a twisted wire 1.

  The outer peripheral resin powder is applied to the outer peripheral surface of the stranded wire 1 with the resin coating 4, and the resin coating 4 and the outer peripheral resin powder previously on the outer peripheral surface of the stranded wire 1 are integrally melted by heating and melting it. .

  By spraying the inorganic coarse particles 7 while cooling the resin coating and cooling it, a thick resin coating 4 containing the inorganic coarse particles 7 is formed on the outer peripheral surface of the stranded wire 1.

  Also, by heating and cooling after the application of the outer peripheral resin powder, the resin coating 4 formed inside the stranded wire 1 is melted to fill the gap between the strands 2 and 3, thereby forming the filled resin layer 6.

(R) Twisted wire → heating → extrusion molding of resin film and filled resin layer → injection of inorganic coarse particles → cooling.
The stranded wire 1 is heated and passed through the crosshead part of the extruder. Since this crosshead part is supplied with a high-temperature resin melt,
The gap 5 between the strands 2 and 3 is filled with the molten resin, and the molten resin is also supplied to the outer peripheral portion of the stranded wire 1 to form a thick resin film 4.

  By spraying and cooling inorganic coarse particles 7 while the resin coating 4 is kept in a molten state, a thick resin coating 4 containing the inorganic coarse particles 7 is formed on the outer peripheral surface of the stranded wire 1. At the same time, the filling resin layer 6 is formed inside the stranded wire 1.

  In the manufacturing process example, the step of applying the resin powder to the strands or the untwisted strands and then heating and melting them was described. After heating the strands or the untwisted strands, You may take the process of apply | coating resin powder and fuse | melting the said resin powder with residual heat.

(Schematic configuration of stranded wire processing equipment)
FIG. 9 is a schematic configuration diagram of the entire processing apparatus for manufacturing the stranded wire 1 with the inorganic coarse particles 7 according to the manufacturing process example (n) of the fifth embodiment.

  As shown in the figure, the stranded wire processing apparatus 10 includes a carry-in device 11 composed of rollers, an electrostatic fluidized immersion device 12, a high-frequency heating device 13, an inorganic coarse particle spraying device 14, and a carry-out device composed of rollers. Mainly composed of 15. These devices are arranged in the order described above along the conveying direction X of the stranded wire 1 to constitute one production line.

The electrostatic fluid dipping device 12 has a powder coating fluid tank 16 in the inside thereof, and performs the adhesion of the powder mainly composed of the PVB resin described above to the stranded wire 1.
The high-frequency heating device 13 has a high-frequency heating coil 17 inside, and performs melting of PVB resin powder.
The inorganic coarse particle spraying device 14 includes an inorganic coarse particle spraying portion 18 and a cooling chamber 19 inside, and performs the above-described spraying of inorganic coarse particles and cooling / solidification of the resin coating 4.
Then, as shown in FIG. 5, a resin coating 4 is formed on the outer peripheral surface from the carry-out device 15, and the treated stranded wire 1 in which the sprayed inorganic coarse particles 7 are partially embedded in the resin coating 4 is continuously carried out. The

  In this way, a series of highly durable anticorrosion treatments for the stranded wire 1 are performed. As shown in FIG. 9, the stranded wire 1 passes through the flow tank 16, the high-frequency heating coil 17, and the spray unit 18. By doing so, a highly durable anticorrosion treatment is performed without rotating the stranded wire 1. Moreover, between the said carrying-in apparatus 11 to the carrying-out apparatus 15, the elongate strand wire 1 is conveyed in the tension | tensile state, without loosening.

  When the stranded wire 1 having only the resin coating 4 formed on the outer peripheral surface as shown in FIG. 2 is manufactured, the inorganic coarse particle spraying device 14 shown in FIG. 9 may be omitted.

(Schematic configuration of electrostatic fluid immersion device)
FIG. 10 is a schematic configuration diagram of the electrostatic fluid immersion apparatus 12 used in the embodiment of the present invention.

  As shown in the figure, the fluid tank 16 is disposed in a powder recovery cover 21. A space 22 is formed in the lower part of the fluid tank 16, a dry air blower pipe 23 is connected to the lower space 22, and a blower 24 is provided at the base of the dry air blower 23.

  A porous electrode 25 is disposed above the space 22, and the porous electrode 25 is connected to the negative electrode of the high voltage generator 26. A porous plate 27 is disposed on the porous electrode 25, and the upper portion of the porous plate 27 is a fluid space 29 that forms a fluidized layer of the powder 28. A powder paint supply pipe 30 is connected to the flow space 29, and a blower 31 is provided at the base of the powder paint supply pipe 30.

  A long stranded wire 1 is inserted through the flow space 29, and the stranded wire 1 is grounded while being conveyed. A sampling tube 32 is inserted into the flow space 29, and a powder amount detector 33 is provided at the base of the sampling tube 32.

  A powder recovery tube 34 is connected to the upper part of the powder recovery cover 21, and an attracting machine 35 is provided in the powder recovery tube 34.

  The dry air 36 is supplied from the blower 24 through the dry air blow pipe 23 to the lower space 22 of the fluid tank 16, while the powder 28 is supplied from the blower 31 through the powder coating material supply pipe 30 to the flow space. 29 is supplied and filled.

  The dry air 36 supplied to the lower space part 22 rises through the porous electrode 25 and the porous plate 27, fluidizes innumerable powders 28 in the flow space part 29 to form a fluidized bed, The stranded wire 1 is immersed in a cloud-like floating layer of the powder 28 formed on the fluidized bed.

  The boundary between the fluidized bed of the powder 28 and the cloud-like floating layer is not clear, but there is a difference in the concentration distribution of the powder 28 between the fluidized bed and the cloud-like floating layer.

  By applying a high voltage (for example, 30 to 120 KV) to the porous electrode 25 by the high voltage generator 26, the dry air 36 passing through the porous electrode 25 is ionized, whereby the powder 28 has a negative charge. Have. On the other hand, the stranded wire 1 is held at a positive charge by the high voltage generator 26. By passing the stranded wire 1 having a positive charge through the floating layer of the powder 28 having a negative charge, the powder 28 is electrostatically attached to the outer peripheral surface of the stranded wire 1 and the charge is stabilized. .

  As described above, the stranded wire 1 passes through the floating layer, so that the powder 28 is well wrapped around the upper side of the stranded wire 1, and the powder 28 adheres almost uniformly to the entire circumference of the stranded wire 1. .

The powder 28 that has not adhered to the stranded wire 1 is recovered from the upper part of the powder recovery cover 21 through the powder recovery tube 34, and is not shown in the figure, but is again transferred to the stranded wire 1. Electrostatic spraying a powder made of a thermosetting resin such as an epoxy resin onto a stranded wire that has reached a high temperature state, and the adhered powder is heated and melted by the heat held by the stranded wire, and the outer periphery of the stranded wire A method of forming a resin film on the surface has been adopted.

  However, in this method, since a non-adhering powder undergoes a slight curing reaction due to heat generated from the stranded wire, reuse of the recovered powder deteriorates the quality of the resin coating. In order to avoid this problem, the yield of the powder is at most about 70%, which is uneconomical and causes an increase in production cost.

  On the other hand, in this embodiment, since the electrostatic fluid immersion apparatus 12 is used, there is no thermal influence on the powder 28, and the PVB resin used in the present invention is thermoplastic, like an epoxy resin. Thus, no curing reaction occurs, that is, the powder 28 does not change in quality. Therefore, 100% of the collected powder 28 can be reused, and the quality of the resin coating is stable even with the reused powder 28.

  Moreover, according to this electrostatic fluid immersion apparatus 12, since powder coating can be performed in the fluid tank 16 without scattering many powders in air | atmosphere, the working environment can be improved.

  The filling state of the powder 28 in the fluidized tank 16 is monitored by the powder amount detector 33, and based on the detection result, the conveying speed of the stranded wire 1, the air flow rate of the dry air 36, the powder 28 The amount of powder 28 attached to the stranded wire 1 can be controlled by adjusting the supply amount and the recovered amount thereof, and thick film coating is possible.

  FIG. 10 shows the case where the stranded wire 1 is processed. However, when the resin coating 4 is formed on the outer peripheral surface of the strands (2, 3) constituting the stranded wire 1, the strands 1 are replaced with the strands 1. The line (2, 3) may be passed through the electrostatic fluid immersion apparatus 12 shown in FIG.

  In addition, as described in the above embodiment, when the resin powder is applied in a state in which the stranded wire is untwisted and divided into the strands 2 and 3, the untwisting is performed to What is necessary is just to pass in the electrostatic fluid immersion apparatus 12 in the state which opened the space | interval.

By passing through the floating layer of the powder 28 with the spacing between the strands 2 and 3, the powder 28 freely flows between the strands 2 and 3, 3 uniformly adhere to the outer peripheral surface.

(Configuration of inorganic coarse particle spraying device)
FIG. 11 is a cross-sectional view of the coarse particle spraying portion 18 in the inorganic coarse particle spraying device 14.

  As shown in the figure, the coarse particle spraying section 18 has a heated air introduction chamber 41, a coarse particle spray chamber 42, and a coarse particle supply pipe 43. The coarse particle supply pipe 43 extends through the heated air introduction chamber 41 and into the coarse particle spray chamber 42.

  The coarse particle blowing chamber 42 is provided adjacent to the heated air introduction chamber 41, and a heated air introduction hole 45 for supplying the heated air 44 from the heated air introduction chamber 41 to the coarse particle blowing chamber 42 is provided in the coarse particle blowing chamber 42. A plurality of (for example, 6 to 8) particles are formed around the particle supply pipe 43.

  The coarse particle spraying chamber 42 is formed in an annular shape so as to surround the insertion hole 46 through which the stranded wire 1 is inserted. And in the inner peripheral part of this coarse particle spray chamber 42, the cross-sectional shape which protruded toward the strand wire 1 to penetrate is attached to the convex narrow part forming member 47, and the front-end | tip part of the narrow part forming member 47, and further A tapered taper-shaped narrowing member 48 is provided.

  The narrow forming member 47 and the narrowing member 48 are formed in an annular shape so as to surround the stranded wire 1, and the narrow narrow forming member 47 and the narrowing member 48 constitute a coarse particle spray gun. A collection passage 49 is provided outside the narrow member 47 and the narrowing member 48.

Position adjustment means (not shown) adjusts the vertical and horizontal positions of the coarse particle spraying portion 18 so that the stranded wire 1 passes through the center of the insertion hole 46 provided in the coarse particle spraying portion 18. Is made. Since the stranded wire 1 passing through the central portion of the insertion hole 46 is conveyed in a tensioned state, the position of the stranded wire 1 in the insertion hole 46 hardly changes.

  The inorganic coarse particles 7 heated to about 100 ° C. or more in advance are vapor-phase-conveyed by coarse particle transport air (not shown) heated to about 100 to 200 ° C. and supplied into the coarse particle spraying chamber 42. Is done.

  On the other hand, the heated air 44 heated to about 100 to 200 ° C. is introduced into the heated air introduction chamber 41 and then supplied into the coarse particle spraying chamber 42 through the plurality of heated air introduction holes 45. Here, the heated air 44 and the coarse particles 7 are mixed to form a uniform mixed flow 50, which reaches the whole of the circular coarse particle spray chamber 42.

  The mixed flow 50 increases the flow rate by passing through the narrow portion at the tip of the narrow forming member 47, and further passes through the narrowing member 48 that gradually narrows in a tapered shape, thereby further increasing the flow rate of the mixed flow 50. It becomes a jet jet.

  On the outer peripheral surface of the stranded wire 1 passing through the center of the narrowing member 50, a resin film that has been melted by the high-frequency heating device 13 (see FIG. 9) is formed, so that the coarse particles ejected from the narrowing member 48 7 adheres to bite into the resin film on the stranded wire 1. Since the spraying of the coarse particles 7 is performed simultaneously over the entire peripheral surface of the stranded wire 1, the adhesion state of the coarse particles 7 is substantially uniform.

  When the coarse particles 7 at room temperature are sprayed on the molten resin film, the surface of the resin film immediately cools and solidifies, so that the coarse particles 7 do not sufficiently penetrate into the resin film, and the resin film ensures the coarse particles 7. It is difficult to fix to. On the other hand, in the present embodiment, since the mixed flow 50 of the coarse particles 7 heated to about 100 ° C. or higher and the heated air 44 of about 100 to 200 ° C. is sprayed on the molten resin film, There is no harmful effect, and the fixed state of the coarse particles 7 is stable.

  Since the coarse particles 7 are sprayed on the resin film while the stranded wire 1 passes through the insertion hole 46, the inner diameter of the insertion hole 46 is such that the coarse particles 7 sprayed on the resin film are not scraped off. Designed.

  Coarse particles 7 and heated air 44 not attached to the stranded wire 1 are sent to a recovery chamber (not shown) through a recovery passage 49 where they are separated and recovered into the coarse particles 7 and heated air 44 for reuse. Is done.

(Concrete example)
Next, specific examples of the present invention will be described.
A 15.2 mm PC strand 1 is passed through the electrostatic fluid immersion apparatus 12 shown in FIG. 9 by one central strand and six outer strands, and PVB resin is placed on the outer circumference of the PC strand 1. A powder coating containing the main component is adhered.

  The degree of butyralization of the PVB resin was 68 mol%, the hydroxyl group content in the molecule was 20 wt%, the average particle size of primary particles was 4 μm, and the average particle size of aggregated particles was 83 μm.

  As an antioxidant, N, N′-hexane-1,6-diylbis [3- (3,5-di-t-butyl-4-hydroxyphenylpropionamide) is used as an antioxidant with respect to 100 parts by weight of the PVB resin powder. And 0.5 parts by weight of the mixture was dry blended, and the mixed powder was supplied to the electrostatic fluidized immersion apparatus 12.

  The outer peripheral surface of the PC twisted wire 1 that has passed through the electrostatic fluid immersion apparatus 12 is PVB resin and N, N′-hexane-1,6-diylbis [3- (3,5-di-t-butyl- 4-hydroxyphenylpropionamide)] (antioxidant) is deposited with a film thickness of 400-800 μm.

  Next, the PC stranded wire 1 is passed through the high-frequency heating device 13 and heated to about 200 to 300 ° C., thereby melting the PVB resin powder coating material and having a substantially uniform film thickness without pinholes. A resin film is formed. Subsequently, the PC stranded wire 1 carrying the molten resin coating is supplied to the inorganic coarse particle spraying device 14.

  In this coarse particle spraying device 14, alumina # 80 (average particle size 210 μm), which is inorganic coarse particles heated to about 150 ° C., is heated on the peripheral surface of the PC stranded wire 1 together with heated air of about 100 to 200 ° C. By spraying almost uniformly and immediately cooling in the cooling chamber 19, the resin film 4 in the molten state is solidified, and the sprayed inorganic coarse particles 7 are fixed by the resin film 4.

  As a result, as shown in FIG. 7 and FIG. 8, the inorganic coarse particles 7 partially protrude from the resin coating 4, and the highly durable anticorrosive PC stranded wire 1 having an innumerable surface state having innumerable protrusions 8 is formed. can get.

Next, the function and effect of each claim of the present invention will be described.
In the invention according to claim 1, the resin film covering at least the outer peripheral surface of the stranded wire has a butyralization degree of 40 to 85 mol%, and the hydroxyl group content in the molecule is restricted to a range of 11 to 27 wt%. It is a resin film mainly composed of polyvinyl butyral resin.

  This film mainly composed of polyvinyl butyral resin has good adhesion to strands (metals), inorganic coarse particles and concrete, has high bending resistance, and does not deteriorate even after long-term outdoor exposure. In addition, it has excellent weather resistance and can sufficiently withstand the alkalinity of concrete.

  In the invention according to claim 2, the resin film covering at least the outer peripheral surface of the stranded wire has a butyral degree of 40 to 85 mol%, and the hydroxyl group content in the molecule is regulated to a range of 11 to 27% by weight. A resin film mainly composed of polyvinyl butyral resin, characterized by having inorganic coarse particles fixed by the resin film and forming innumerable protrusions protruding from the surface of the resin film. is there.

  The film mainly composed of this polyvinyl butyral resin has the above-described features. And since the innumerable protrusion part by the inorganic coarse particle is formed in the resin surface, the extraction strength from concrete can be raised.

  The invention described in claim 3 is characterized in that the resin film contains an organic antioxidant having a specific molecular structural formula.

  Therefore, the effect of preventing oxidation of the resin film can be sufficiently exhibited, the bending resistance of the resin film can be maintained for a long period of time, and the resin film is not easily peeled off from or cracked against the strands.

  The stranded wire according to the present invention is suitable for a structure in a place particularly severe in corrosive environment conditions such as a building structure such as a building, a civil engineering structure, a bridge structure, a marine structure, a rockfall protection net, and various external cables. ing.

  1: Stranded wire, 2: Center strand, 3: Perimeter strand, 4: Resin coating, 5: Void, 6: Filled resin layer, 7: Coarse inorganic particles, 8: Protruding part, 10: Stranded wire processing device, 11: Loading device, 12: Electrostatic fluid immersion device, 13: High frequency heating device, 14: Inorganic coarse particle spraying device, 15: Unloading device, 16: Fluid tank, 17: High frequency heating coil, 18: Inorganic coarse particle blowing Attaching part, 19: cooling chamber, 21: powder recovery cover, 22: lower space part, 23: dry air blowing pipe, 24: blower, 25: porous electrode, 26: high voltage generator, 27: porous plate , 28: powder, 29: fluid space portion, 30: powder coating supply pipe, 31: blower, 32: sampling pipe, 33: powder amount detector, 34: powder recovery pipe, 35: attractor, 36 : Dry air, 41: Heated air introduction chamber, 42: Coarse particle spray chamber, 43: Coarse particle supply , 44: hot air, 45: hot air inlet hole, 46: through hole, 47: narrow member, 48: narrowing member, 49: recovery passage, 50: mixed flow, X: Stranded conveying direction.

In the example of the manufacturing process, the step of applying resin powder to the strand and then heating and melting was described. However, the strand is heated, and then the resin powder is applied, and the resin powder is applied by residual heat. A step of melting may be taken.

Claims (3)

In a stranded wire having a resin film formed at least on the outer peripheral surface side,
The resin film is a resin film mainly composed of a polyvinyl butyral resin having a butyralization degree of 40 to 85 mol% and a hydroxyl group content in the molecule of 11 to 27% by weight. Characteristic stranded wire. In a stranded wire having a resin film formed at least on the outer peripheral surface side,
The resin film is a resin film mainly composed of a polyvinyl butyral resin having a butyralization degree of 40 to 85 mol% and a hydroxyl group content in the molecule of 11 to 27% by weight,
A stranded wire having inorganic coarse particles fixed by the resin coating and forming innumerable protrusions protruding from the surface of the resin coating. In the stranded wire according to claim 1 or 2,
The stranded wire, wherein the resin film contains an organic antioxidant having a molecular structural formula of 5% by weight or less based on the polyvinyl butyral resin.

In the formula, R1 to R8: a linear or branched alkyl group having 1 to 4 carbon atoms or hydrogen,
l, m, n: each an integer of 1 to 10,
X: N or O heteroatom.

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