The present invention is a structure used for the piezoelectric element, braided piezoelectric element is coated with a conductive layer braid using piezoelectric fiber, to fabrics like piezoelectric elements and devices using them with the braided piezoelectric element.
BACKGROUND
[0002]
　Conventionally, techniques are disclosed a number related to the element using a piezoelectric material. For example, for devices coated with piezoelectric polymer conductive fibers in Patent Document 1, it is disclosed that the electrical response is excellent for rubbing. Regarding element wound with piezoelectric polymer in a coil shape in the non-patent document 1, electrical response example due to the expansion and contraction in the axial direction of the coil and the torsional deformation about the axis of the coil is disclosed. The Patent Document 2 discloses a fibrous material made of a piezoelectric polymer, the fibrous material is described as a piezoelectric effect occurs largely when worked parallel or perpendicular force and the fiber axis (movement) of ing.
　Piezoelectric sheet of Patent Document 3 can output an electrical signal by the expansion and contraction deformation to the piezoelectric sheet (stress). However, in the first place poor in flexibility because it is a sheet-like, such usage can be freely bent as fibers and cloth is not possible.
[0003]
　However the above prior art documents, while generating efficiently piezoelectric signal to stretching movement, for the exercises other than the expansion and contraction does not disclose a specific configuration so as not to generate a piezoelectric signal. Further, to increase the utilization efficiency of the piezoelectric signal, not disclosed for the central axis and the outer opposite polarity charge to each other (ie opposite sign charge) concrete structure to generate a structure. Therefore, performance of the piezoelectric elements can be used such as sensors and adsorbent was insufficient.
[0004]
　In addition, in recent years, so-called wearable sensor has attracted attention, products of shape, such as glasses type and watch began out into the world. However, these devices, there is a sense of wearing, the ultimate wearable, cloth-like and that is shaped like a garment that is desired. Such sensors, a piezoelectric element is known using a piezoelectric effect of the piezoelectric fibers. For example, Patent Document 1 includes two conductive fibers and one of the piezoelectric fibers, while having these contacts each other, the piezoelectric element is disclosed comprising a piezoelectric units are arranged on substantially the same plane It is. Further, Patent Document 2, a fibrous material made of a piezoelectric polymer, or a molded product, in order to generate a piezoelectric by the tension which is added thereto in the axial direction, in a direction different from the addition direction of such tension piezoelectric material is disclosed which is characterized by being configured by adding torsion.
[0005]
　On the other hand, in recent years, input to a so-called touch panel system device, i.e. touch input device has increased significantly. Not only ticket vending machines of bank ATM and the train station, a smart phone, a cellular phone, a portable game machine, such as in portable music players, coupled with the development of flat-panel display technology, adopted the touch panel system as an input interface device has increased significantly . As means for realizing such a touch panel method, a method using a piezoelectric sheet or piezoelectric fibers are known. For example, Patent Document 4, a touch panel using a piezoelectric sheet made of poly-L-lactic acid having a stretching axis oriented in a predetermined direction is disclosed.
[0006]
　The sensor of these wearable sensors and touch panel, even for little stress generated in the piezoelectric material by small deformations applied to the piezoelectric material, be taken out large electrical signal is desired. For example, it is desired to take out even a large electric signal stably by a relatively small stress generated in the piezoelectric material by the act of rubbing the surface with such bending and stretching operation and the finger.
[0007]
　The piezoelectric fibers of Patent Document 1 is an excellent material which can be applied to various applications, not necessarily though not the relatively capable of outputting a large electric signals to occur stress with small variations, to obtain a large electrical signal not explicitly also for the technology. The piezoelectric element described in Patent Document 1, susceptible to noise for conductive fiber as a signal line is exposed, and susceptible to deterioration or damage of the material due to external stress. Furthermore, it does not disclose a structure that allows convenient installation the piezoelectric element to a substrate such as another fabric, in the piezoelectric element described in Patent Document 1, still has room for improvement with respect to practical use .
[0008]
　The piezoelectric fibers of Patent Document 2, by keeping was previously twisted piezoelectric fibers in a special manufacturing method, it outputs an electric signal to the tension or compression to the piezoelectric fibers. However, Patent Document 2, the bending and the bend or stretch the piezoelectric fibers, techniques for generating sufficient electrical signal to the shear stress due to the act of rubbing the surface of the piezoelectric fibers is not disclosed. Therefore, when using such a piezoelectric fiber, it is difficult to take out just enough electrical signal stresses occurring at relatively small deformations such as rubbing the surface.
[0009]
　Piezoelectric sheet of Patent Document 4 can output an electrical signal by the deformation to the piezoelectric sheet (stress). However, the first place such usage can be freely bent as poor cloth in flexibility in order in the form of a sheet is not possible.
CITATION
Patent Document
[0010]
Patent Document 1: WO 2014/058077
Patent Document 2: JP 2000-144545 Patent Publication
Patent Document 3: JP 2014-240842 Patent Publication
Patent Document 4: JP 2011-253517 JP
Non-patent literature
[0011]
Non-Patent Document 1: Japanese Journal of Applied Physics 51, Volume 09LD16 page
Summary of the Invention
Problems that the Invention is to Solve
[0012]
　The present invention has been made in consideration of the above situation, the first object of the present invention, selectively responding to cause efficient available electric polarization with respect to stretching deformation (stress) and to provide a capable cylindrical or cylindrical piezoelectric structure.
[0013]
　A second object of the present invention, by stress generated by the relatively small deformations, can be taken out large electrical signal, also is capable of suppressing a noise signal, further less susceptible to damage from external fibrous to provide a piezoelectric element.
[0014]
　A third object of the present invention, by stress generated by the relatively small deformation, large electrical signal can be taken out, using the piezoelectric element of fibrous capable of suppressing noise signals, and other fabrics like to provide a fabric-like piezoelectric element can be simply placed into the substrate.
Means for Solving the Problems
[0015]
　The present inventors have found that the first result of intensive studies to achieve the purpose of high those to align the piezoelectric polymer having a piezoelectric constant d14, the cylindrical or cylindrical side by a specific orientation structure with the body, efficiently found that is generated the opposite polarity charge to the central axis side and the outer cylindrical or cylindrical with respect to expansion deformation, thereby achieving the present invention.
[0016]
　Further, the present inventors have found that the second As a result of intensive studies to achieve the object, as a combination of conductive fibers and piezoelectric fibers, braided piezoelectric fiber surface of the conductive fiber comprising a core in coated, can be further efficiently extracted electric signals by braided piezoelectric element provided with a conductive layer on its periphery, and discovered that can suppress the noise signal, further the core and piezoelectric fiber thickness It found that made the relationship less susceptible to damage from external by a specific range, reaching the present invention.
[0017]
　Furthermore, the present inventors have found that the third As a result of intensive studies to achieve the object, as a combination of conductive fibers and piezoelectric fibers, braided piezoelectric fiber surface of the conductive fiber comprising a core in covering, further it can be efficiently extracted electric signals by braided piezoelectric element provided with a conductive layer on its periphery, to further discovered that the noise signal can be suppressed, securing it to the fabric with a particular shape in, found that will be able to easily install less susceptible to damage from the outside and to substrates such as another fabric, we have reached the present invention.
[0018]
　That is, according to the present invention, the following (1) to (12) are provided as a means for achieving the first object (the first invention), means for achieving the second object (second invention) below (13) to (20) is provided as a means for achieving the third object (third invention) below (21) to (31) is provided as.
(1) a structure arranged oriented piezoelectric polymer to a cylindrical or cylindrical, the orientation angle of the piezoelectric polymer relative to the direction of the central axis of the cylindrical or columnar shaped piezoelectric polymer is arranged and at 15 ° or more 75 ° or less, the piezoelectric polymer is mainly a crystalline polymer having an absolute value less 0.1pC / N or more 1000pC / N value of the piezoelectric constant d14 when the 3-axis alignment axis wherein the component further the piezoelectric polymer may include a P body the value of the piezoelectric constant d14 contains a positive crystalline polymer as a main component, and N containing the negative of the crystalline polymer as a main component, the portion where the center axis of the structure has a length of 1 cm, the weight of the P body orientation axis is arranged by winding a spiral Z twist direction ZP, orientation axis by winding a spiral S-twist direction array helix the weight of the P body that is SP, the orientation axis Z lay direction ZN the mass of placed the N body by winding, the weight of the N body orientation axis is arranged by winding a spiral S twist direction and SN, and the smaller of the (ZP + SN) and (SP + ZN) the T1, when a larger one T2, the value of T1 / T2 is 0 to 0.8, structure.
(2) the piezoelectric polymer comprises as a main component polylactic -L- acid or poly -D- acid structure according to (1).
(3) the piezoelectric polymer comprises a P comprising poly -D- acid as the main component, and an N body comprising poly -L- acid as the main component, a structure according to (2).
(4) when said telescopic deformation in the direction of the piezoelectric polymer is cylindrical is arranged or cylindrical center axis of the given, charges of opposite polarity to the central axis side and outer cylindrical shape or cylindrical shaped It occurs, (1) - structure according to any one of (3).
(5) The piezoelectric polymer is fibrous, those filamentary or tape-like, braided, twisted cord-like, and is constituted by a covering thread or pull aligned thread, of (1) to (4) structure according to any one.
(6) the piezoelectric polymer constitutes only one closed area in a cross section perpendicular to the cylindrical or cylindrical central axis of the structure according to any one of (1) to (4) .
(7) (1) to (6) and the structure according to any one of the element comprising a conductive body and disposed adjacent to the structure.
(8) The piezoelectric polymer is arranged in a cylindrical and disposed the conductor to the position of the central axis of the cylindrical element described in (7).
(9) the now conductors from conductive fibers, wherein the piezoelectric polymer is arranged to be assembled in a braided around the conductive fibers as a piezoelectric fiber, element according to (8).
(10) piezoelectric polymer has arranged the conductor on the outside of the deployed cylindrical or cylindrical, element according to (7).
(11) the conductor is made of conductive fibers, wherein the piezoelectric polymer is a conductive fiber around the arranged cylindrical or cylindrical is arranged to be assembled in a braided, according to (10) element of.
(12) and the device according to any one of (7) to (11),
　Depending on the charge piezoelectric polymer occurs when the elastic deformation in the direction of the central axis of the arranged cylindrical or cylindrical is given, and an output terminal for an electrical signal generated by the conductor is output,
　sensor and an electric circuit for detecting an electric signal which is output through the output terminal.
(13) and said conductive fiber core formed by a device according to the braid-like so as to cover the core portion and a sheath portion formed of a piezoelectric fibers (9),
　wherein a conductive layer provided around the sheath
includes a is the ratio d / Rc of the thickness d of the layer of piezoelectric fibers are 1.0 or more to the radius Rc of the core, braided piezoelectric element.
(14) the coverage of the sheath portion by the conductive layer is 25% or more, braided piezoelectric element according to (13).
(15) the conductive layer is formed by fibers, braided piezoelectric element according to (13) or (14).
(16) (13) fabric-like piezoelectric element comprising a braided piezoelectric element according to any one of - (15).
(17) the fabric further comprises conductive fibers in contact intersects the at least a portion of the braided piezoelectric element, the fabric-like piezoelectric element according to (16).
(18) more than 30% of the fibers crossing the a fibers forming fabric and the braided piezoelectric element is conductive fibers, cloth-like piezoelectric element according to (17).
(19) (13) to the braided piezoelectric element according to any one of (15),
　and amplifying means for amplifying the electric signal output from said braided piezoelectric element in response to applied pressure,
　And output means for outputting the electrical signal amplified by the amplifying means
　devices with.
(20) and the cloth-like piezoelectric element according to (17) or (18),
　and amplifying means for amplifying the electric signal output from said fabric-like piezoelectric element in response to applied pressure,
　is amplified by the amplifying means and output means for outputting an electrical signal,
　the device comprising a.
(21) a fabric-like piezoelectric element braided piezoelectric element is fixed to the fabric, the braided piezoelectric element,
　a core part formed by the conductive fibers, braided of so as to cover the core portion and device according to and a sheath portion formed of the piezoelectric fibers (9),
　a conductive layer provided on the periphery of the sheath
provided with, per 5cm of the braided piezoelectric element relative to the fabric pullout strength is 0.1N or higher, cloth-like piezoelectric element.
(22) the coverage of the braided piezoelectric element by fibers constituting the fabric is more than 30% on both sides of the fabric, fabric-like piezoelectric element according to (21).
(23) wherein the fabric braided piezoelectric element is fixed in a state or knitted state is woven, fabric-like piezoelectric element according to (21) or (22).
(24) the interlayer of the double woven fabric or a double knit fabric braided piezoelectric element is sandwiched, fabric-like piezoelectric element according to (21) or (22).
(25) the and the from the fabric braided piezoelectric element is partially exposed, the conductive fibers and / or the conductive layer and the other member is electrically connected to the braided piezoelectric element in the exposed portion is, cloth-like piezoelectric element according to any one of (21) to (24).
(26) the coverage of the sheath portion by the conductive layer is 25% or more, (21) a fabric-like piezoelectric element as claimed in any one of - (25).
(27) the conductive layer is formed by fibers, cloth-like piezoelectric element according to any one of (21) to (26).
(28) the total fineness of the piezoelectric fibers, the conductive fibers total fineness 1 times or more of it is 20 times or less, the fabric-like piezoelectric element according to any one of (21) to (27).
(29) one per fineness of the piezoelectric fibers, the conductive fibers total fineness of 1/20 or more, it is 2 times or less, the fabric according to any one of (21) - (28) Jo piezoelectric element.
(30) the fabric, at least a portion further comprises an electrically conductive fiber in contact crossing, (21) a fabric-like piezoelectric element according to any one of - (29) of the braided piezoelectric element.
(31) (21) and the cloth-like piezoelectric element as claimed in any one - (30),
　an electric signal output from said electrically conductive fibers in accordance with the applied pressure is contained in the cloth-like piezoelectric element an electric circuit for detecting,
　the device comprising a.
Effect of the invention
[0019]
　By the first invention, Elastic selectively respond to (stress), can provide an efficient cylindrical capable of causing the available electric polarization or cylindrical piezoelectric structure.
[0020]
　Further, by the second invention, by stress generated by the relatively small deformations, it can be taken out large electrical signal can provide a piezoelectric element fibrous can further suppress noise signals.
[0021]
　Further, by the third invention, by stress generated by the relatively small deformation, large electrical signal can be taken out, using the piezoelectric element of fibrous capable of suppressing noise signals, and other substrates such as fabric It can provide fabric-like piezoelectric element can be easily installed to. Furthermore, according to the third invention, the predetermined value coverage on both sides of the fabric of braided piezoelectric element by the fibers constituting the fabric, for example, by such more than 50%, rubbing from the outside, heat, it is possible to hardly damaged due to light.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022]
[FIG. 1A] is a schematic view showing a cylindrical piezoelectric structure according to an embodiment of the first invention.
[FIG 1B] is a schematic view showing a piezoelectric structure cylindrical according to an embodiment of the first invention.
FIG. 2 is a side view showing the cylindrical piezoelectric structure according to an embodiment of the first invention.
3 is a schematic view for explaining the method of calculating the orientation angle theta.
It is a schematic view showing a configuration example of a braided piezoelectric element according to the embodiment of FIG. 4 the first invention.
Is a schematic view showing a configuration example of a cloth-like piezoelectric element in accordance with the embodiment of FIG. 5 the first invention.
6 is a block diagram illustrating a device comprising a piezoelectric element according to the embodiment of the first to third aspects of the invention.
7 is a schematic diagram showing a configuration example of a device comprising a fabric-like piezoelectric element according to the embodiment of the first invention.
8 is a schematic diagram showing another configuration example of a device comprising a fabric-like piezoelectric element according to the embodiment of the first invention.
[FIG 9A] is a micrograph showing a cross section of braided piezoelectric element according to the embodiment.
[FIG. 9B] is a micrograph showing a cross section of braided piezoelectric element according to the embodiment.
[FIG 9C] is a micrograph showing a cross section of braided piezoelectric element according to the embodiment.
FIG. 10 is a schematic diagram showing a configuration example of a braided piezoelectric element according to an embodiment of the second invention and the third invention.
11 is a micrograph showing a cross section of braided piezoelectric element according to an embodiment of the second invention.
12 is a schematic diagram showing a configuration example of a cloth-like piezoelectric element according to an embodiment of the second invention.
13 is a schematic diagram showing a configuration example of a device comprising a braided piezoelectric element according to an embodiment of the second invention.
14 is a schematic diagram showing a configuration example of a device comprising a fabric-like piezoelectric element according to an embodiment of the second invention.
15 is a schematic diagram showing another configuration example of a device comprising a fabric-like piezoelectric element according to an embodiment of the second invention.
FIG. 16 is a schematic diagram showing another configuration example of a device comprising a fabric-like piezoelectric element according to an embodiment of the second invention.
17 is a schematic diagram showing a configuration example of a cloth-like piezoelectric element according to the embodiment of the third invention.
18 is a schematic diagram showing another configuration example of a cloth-like piezoelectric element according to the embodiment of the third invention.
19 is a schematic diagram showing another configuration example of a cloth-like piezoelectric element according to the embodiment of the third invention.
[Figure 20] is a schematic diagram showing another configuration example of a cloth-like piezoelectric element according to the embodiment of the third invention, (a) is a perspective view, (b) is a side view.
21 is a schematic diagram showing a configuration example of a device comprising a fabric-like piezoelectric element according to the embodiment of the third invention.
FIG. 22 is a schematic diagram showing another configuration example of a device comprising a fabric-like piezoelectric element according to the embodiment of the third invention.
FIG. 23 is a schematic diagram showing another configuration example of a device comprising a fabric-like piezoelectric element according to the embodiment of the third invention.
DESCRIPTION OF THE INVENTION
[0023]
　It will be described in detail for the first invention.
(Cylindrical or cylindrical piezoelectric structure)
　structure of the present invention (piezoelectric structure) includes a piezoelectric polymer oriented, oriented piezoelectric polymer is placed in a cylindrical or cylindrical . 1A is a schematic view showing a piezoelectric structure 1-1 cylindrical according to the embodiment, FIG. 1B is a schematic view showing a piezoelectric structure 1-2 cylindrical according to the embodiment. The shape of the outer edge and the inner edge of the bottom surface of the cylindrical or columnar shaped piezoelectric polymer is placed is most preferably a true circle, it may be oval, or a flattened circular.
[0024]
(Piezoelectric polymer)
　piezoelectric polymer contained in the piezoelectric structure of the present invention is a molded body of a polymer which is uniaxially oriented, the absolute value of the piezoelectric constant d14 of when the orientation axis and three axes 0 the crystalline polymer having the following values .1pC / N or more 1000pC / N as main components. "Comprising as a main component" in the present invention refers it accounts for more than 50% by weight of the components. Further, the crystalline polymer in the present invention, a 1 wt% or more crystalline portion is a polymer comprising a amorphous portion other than the crystal unit, the crystalline portion and the amorphous portion and the mass of the crystalline polymer a mass of the sum of and.
　Can be suitably used as the crystalline polymer contained in the piezoelectric polymer of the present embodiment, the absolute value is less 0.1pC / N or more 1000pC / N value of the piezoelectric constant d14 of when the orientation axis and three axes the crystalline polymer having, for example, "Piezoelectricity of biopolymers" (Eiichi Fukada, Biorheology, Vol.3, No.6, pp.593) as shown in, cellulose, collagen, keratin, fibrin, poly -L- alanine, poly -γ- methyl -L- glutamate, poly -γ- benzyl -L- glutamate, may be mentioned poly -L- acid. Further, poly -D- alanine optical isomers of these polymers, poly -γ- methyl -D- glutamate, poly -γ- benzyl -D- glutamate, poly -D- lactic code d14 is Gyakuto It becomes, but as the absolute value of d14 is estimated to take the same value. The value of d14 show different values ​​depending molding conditions and the purity and measurement atmosphere, but to achieve the object of the present invention, actually the crystalline polymer in the piezoelectric polymer used crystallinity and crystal orientation degrees measured therewith a uniaxially stretched film having the same crystallinity and degree of crystal orientation created using the crystalline polymer, the absolute value of d14 of the film is at a temperature that is actually used 0 .1pC / N or more 1000pC / N may be Shimese the following values, as the crystalline polymer contained in the piezoelectric polymer of the present embodiment is not limited to the particular crystalline polymer listed above. Although measurement of the d14 of the film samples may take various known methods, for example a sample with metal is deposited electrodes on both surfaces of the film sample, rectangle having four sides from the stretching direction 45 degrees inclined direction the cut, by measuring charges produced on both sides of the electrode when subjected to tensile load in its longitudinal direction, it is possible to measure the value of d14.
[0025]
　In this embodiment the poly -L- lactic acid and poly -D- acid are particularly preferably used. Poly -L- lactic acid and poly -D- acid shows a piezoelectric exceeding 10pC / N as the absolute value of d14 example readily oriented crystallization by uniaxial stretching after melt film. On the other hand, the polarization treatment of the typical polyvinylidene fluoride moldings are piezoelectric polymer has a piezoelectric constant of the high d33, very low in absolute value of d14, it is used as the crystalline polymer of the present invention it can not be.
[0026]
　Poly -L- acid, respectively polylactic -D- lactic acid, for the polarization for the same stress are reversed, that the present invention by taking the arrangement specific as described below, to form a more preferable structure It can become.
[0027]
　The piezoelectric polymer may be used as alloy of polymers that do not exhibit the other piezoelectric but, if used polylactic acid as a main piezoelectric polymer, at least 60 wt% or more of the total mass of the alloy as a reference in preferably contains the polylactic acid, more preferably 70 mass% or more, and most preferably at least 90 mass%.
[0028]
　The polymer other than polylactic acid in the case of the alloy, polybutylene terephthalate, polyethylene terephthalate, polyethylene naphthalate copolymers, polymethacrylates, and the like as a preferable example, but not limited thereto.
[0029]
(Orientation angle of the piezoelectric polymer)
　in the structure where the piezoelectric polymer arranged in a cylindrical or columnar form of the invention, the central axis of the cylindrical or columnar shaped piezoelectric polymer is disposed (hereinafter, simply " the orientation angle θ of the piezoelectric polymer relative to the direction of to as the central axis ") is 15 ° or more 75 ° or less. When this condition is satisfied, by giving a direction of the center axis of the Elastic respect piezoelectric structure (tensile stress and compressive stress), a piezoelectric effect corresponding to the piezoelectric constant d14 of the crystalline polymer contained in the piezoelectric polymer efficiently utilized, it can be generated efficiently charges of opposite polarity to the central axis side and outer piezoelectric structure. From this viewpoint, it is preferred that the orientation angle θ of the piezoelectric polymer is less than 65 ° 25 ° or more with respect to the direction of the central axis, more preferably at 35 ° or more 55 ° or less, at 40 ° to 50 ° there it is more preferable. With this arrangement of piezoelectric polymer, the orientation direction of the piezoelectric polymer will be spiraling.
[0030]
　Further, by arranging the piezoelectric polymer, shear deformation and that rubbing the surface of the piezoelectric structure, bending or deformation as bending the central axis, with respect to torsional deformation around an axis on the central axis it can be a piezoelectric so as not to generate a large charge on the central axis side and the outside of the structure, i.e. piezoelectric structures to generate a selectively large charge with respect to the central axis of the telescopic.
　The orientation angle θ of the piezoelectric polymer relative to the direction of the central axis, the parallel projection view of a cylindrical or columnar shaped piezoelectric polymer is placed from the side, the direction of the central axis, overlaps the central axis Te is the angle which the orientation direction forms the piezoelectric polymer of the portion in front. For example, FIG. 2 is a view of the piezoelectric structure 1 of cylindrical form according to the embodiment from the side. In the example of FIG. 2, the piezoelectric structure is a structure wound with tape of the piezoelectric polymer oriented in the longitudinal direction in a spiral shape. Line indicating the orientation direction of the tape portion at the near side overlaps the center axis CL is OL, the angle between CL and OL theta (the 0 degree or more and 90 degrees or less), a piezoelectric high with respect to the direction of the central axis it is the orientation angle of the molecule.
[0031]
　Due to the use of a thin piezoelectric polymer as a tape in FIG. 2, the alignment direction of the piezoelectric polymer is generally coincides with the orientation direction of the tape surface was observed from the side, with a thick piezoelectric polymer cylinder If made piezoelectric structure shape and, in the case of cylindrical piezoelectric structure, compared with the orientation direction of the surface which can be observed from the side, the orientation direction of the interior is close to the direction of the central axis closer to the central axis It made for differences between the direction and the inside of the alignment direction orientation of the surface occurs. Further, the alignment direction of the tape surface was observed from the side since the apparent taking an S-or inverted S-shape, it requires high magnification magnified observation for accurate observation.
[0032]
　From this point of view, the orientation angle θ of the piezoelectric polymer relative to the direction of the central axis, oriented fibers in the longitudinal direction, a structure wound filament or tape helically (eg twine, covering yarn, braids and the like in the case of), it is measured by the following method as much as possible. Taking a side photograph of the piezoelectric structure, to measure the helical pitch HP of piezoelectric polymer 2. As the helical pitch HP is 3, required until coming to the surface again from one piezoelectric polymer 2 surface around the back surface is a straight line distance between the center axis direction. Further, after fixing the structure by an adhesive if necessary, and photographed cut out the section vertical to the central axis of the piezoelectric structure, measuring the outer radius Ro and an inner radius Ri of the portion piezoelectric structure occupies to. Outer and inner edges of the cross section in the case of oval or flattened circle, the average value of the major axis and the minor axis and Ro and Ri. Piezoelectric structure in the case of cylindrical and Ri = 0. Calculating the orientation angle θ of the piezoelectric polymer relative to the direction of the central axis from the following equation.
　θ = arctan (2πRm / HP) (0 ° ≦ θ ≦ 90 °)
　although = 2 Rm (Ro 3 -Ri 3 ) / 3 (Ro 2 -Ri 2 ), i.e. in the cross-sectional area weighted average of the piezoelectric structure it is the radius.
[0033]
　Piezoelectric polymer in a side photograph of the piezoelectric structure has a uniform surface, if the helical pitch of the piezoelectric polymer can not be determined, passing through the central axis of the piezoelectric structure and fixed with adhesive or the like fractured in a plane, in a direction perpendicular to the fractured, subjected to wide angle X-ray diffraction analysis to transmit X-rays in a sufficiently narrow range so as to pass through the central axis, taking the angle between the center axis to determine the orientation direction , and θ.
[0034]
　As braid or multiple covering yarn, there will spiral drawn along the orientation direction of the piezoelectric polymer, two or more helices having different helical direction (S twist direction or Z twist direction) Yara plugs pitch simultaneously for piezoelectric structures, respectively perform the above measured piezoelectric polymer in each helical direction and helical pitch, a piezoelectric polymer of any one helical direction and the helical pitch that satisfies the condition described above is necessary.
[0035]
　However, the polarity of charges produced on the central axis side and the outer side with respect to the central axis of the telescopic deformation of the piezoelectric structure (reference numeral) along the alignment direction of a piezoelectric polymer to a helix of S-twist arrangement and the case has, the orientation direction of the same piezoelectric polymer in the case of arranging along the spiral of the Z twist is to become the opposite polarities, along the alignment direction of a piezoelectric polymer to a helix of S-twist If you place arranged for the simultaneously along the helix Z twist (for example, when teamed with braid using a fiber made from one piezoelectric polymer both yarn S twist direction of the yarns and Z twist direction), stretching deformation since the generated charge can not be efficiently utilized cancel each other in the S twist direction and the Z twist direction with respect to not preferred. Thus, as an aspect of the present invention, a piezoelectric polymer, a P body comprising as a main component a crystalline polymer the value is a positive piezoelectric constant d14, and N containing the negative of the crystalline polymer as a main component hints, the portion where the central axis of the piezoelectric structure having a length of 1 cm, spiral mass of P body arranged by winding a spiral orientation axis Z twist direction ZP, the orientation axis S twist direction the mass of the deployed P body by winding a SP, ZN mass axis of orientation is arranged by winding a spiral Z lay direction the N bodies, N body orientation axis is arranged by winding a spiral S-twist direction the mass SN, and, (ZP + SN) and (SP + ZN) the smaller of the T1, when a larger one T2, is 0.8 or less the value of T1 / T2 is less than 0, preferably 0 or 0 .5 is less than or equal to. In particular, piezoelectric polymer, a P body comprising poly -D- acid as the main component, and a N comprising poly -L- acid as the main component, the central axis of the piezoelectric structure is 1cm long for parts with is, ZP mass orientation axis Z twist direction is arranged by winding a spiral P-body, the orientation axis of the mass of the P body arranged by winding a spiral S twist direction SP, the orientation axis There was ZN mass of N bodies arranged by winding a spiral Z twist direction, the orientation axis of the mass of the N bodies arranged by winding a spiral S twist direction and SN, the (ZP + SN) and (SP + ZN) of the smaller T1, when the larger was the T2, the value of T1 / T2
　Furthermore, as poly -L- lactic acid and poly--D- acid, a piezoelectric polymer comprising different crystalline polymer sign of d14 each other, and mixed along one spiral of S twist or Z twist placing, for generating charge for elastic is unavailable efficiently cancel each other, which is not preferable.
[0036]
(Piezoelectric configuration of structure)
　As described above, in the piezoelectric structure of the present invention, the alignment direction of the piezoelectric polymer is arranged to draw a spiral. Such particular as an arrangement to become piezoelectric structures such fibers to align the piezoelectric polymer in the longitudinal direction, using a filament or tape, twisted, covering yarn, and as is preferred aspects like braid. When using a tape, using a tape was oriented in a direction other than the longitudinal direction of the tape, and that wound spirally, also be used those molded cylinder and parallel to the longitudinal direction and the central axis it can. From the viewpoint of improvement of the orientation degree and productivity, the fibers were oriented in the longitudinal direction by stretching, twisting using a filament or tape, and more preferably covering yarn and braid, from the viewpoint of the stability of the structure, braid especially preferable.
[0037]
　Piezoelectric structure of the present invention, when given stretch deformation in the direction of the central axis, opposite polarity charges are generated on the central axis side and the outer. Its usage form is not particularly limited, operation by adsorption and desorption and attraction / repulsion of materials, electromagnetic wave generation, but can also be used for an electric stimulation to the living body, for taking out efficiently the charges as a signal and energy, the center axis side and / or forms to be arranged conductor outside is more preferable. When placing the conductor on the outside is more preferable in that it can be used as efficiency and shields it charges to arrange the conductive body so as to cover the entire cylindrical side or cylindrical side surface of the piezoelectric structure, a conductive body only partially be disposed.
　Productivity, folding endurance, from the viewpoint of the stability of the structure, braided piezoelectric structure to be described below are most preferred.
[0038]
(Braided piezoelectric element)
　braided piezoelectric structure 4 according to the embodiment (hereinafter, referred to as braided piezoelectric element) is a schematic view showing a configuration example of a.
　Braided piezoelectric element 101 includes a core 103 formed by the conductive fibers B, and the sheath portion 102 formed by braided piezoelectric fibers A so as to cover the core 103 includes a sheath part 102 is a piezoelectric structure cylindrical in the present invention. Piezoelectric fibers A may include a polylactic acid as a main component.
[0039]
　In braided piezoelectric element 101, the outer peripheral surface of at least one of the conductive fibers B are a number of piezoelectric fibers A surrounds dense. When deformation occurs in the braided piezoelectric element 101, stress due to deformation occurs in the respective plurality of piezoelectric fibers A, whereby an electric field is generated in the respective plurality of piezoelectric fibers A (piezoelectric effect), as a result, the conductive fibers B voltage change by superimposing an electric field of a number of piezoelectric fibers a surrounding is presumed to arise in the conductive fibers B. That electrical signal from the conductive fibers B as compared with the case of not using the braided sheath portion 102 of the piezoelectric fibers A is increased. Thus, the braided piezoelectric element 101, by stress generated by the relatively small deformation, it is possible to take out a large electrical signal. The conductive fibers B may be a plurality of lines.
　Here, of course that the contact state of the signal intensity detected via the conductive fiber B is a core part and the piezoelectric fibers A is a sheath unchanged, it is preferable that the constrained stronger. For example, by increasing the tension when Crossed piezoelectric fibers in braiding machine, it is possible to obtain a more strongly constrained braid. On the other hand, polylactic acid (PLA) fiber strength is weak, and since the high friction, the fibers in the braiding machine of the yarn path undergoes a single yarn breakage, it may be impossible to obtain a beautiful braid. That is, in braiding process, since the fibers by a route carrier for holding a bobbin wound with the fiber moves surface plate is gradually braided while repeating loosened or stretched by accumulation of the bobbin momentarily generally PLA fibers it is difficult to braiding over a period of high tension. However, such difficulties were found to be improved by applying twisting processed into PLA fibers. Specifically, it is preferably subjected to twisting processing in twist number of 10 ~ 5000T / m to PLA fibers. 10T / m is smaller than a is not obtained the effect of twisting, the greater 5000T / m, made trouble prone during fiber tends twist processing. Further, the angle of the orientation axis direction of the PLA is no longer suitable for the axial deformation of the braid when the braid, there is a risk that the signal strength decreases. Number of twists is more preferably at least 30T / m, still more preferably 50T / m or more. The upper limit number of twist less, more preferably 3000T / m, more preferably not more than 1500T / m. The method of twisting process is not particularly limited, any twisting processing method known can be applied. Moreover, twisting processed fiber is preferably heat treated, twisted state is easier to handle the fibers are immobilized by heat treatment. The method of heat treatment is not particularly limited, the temperature generally of interest fibers Tg ~ Tm is preferably selected, the program may be processed by the humidity.
[0040]
　Here, the piezoelectric fibers A preferably contains a polylactic acid as a main component. It is preferred that the lactic acid unit in the polylactic acid is 90 mol% or more, more preferably 95 mol% or more, more preferably 98 mol% or more.
[0041]
　In braided piezoelectric element 101, as far as it achieves the object of the present invention, it may be performed commingled etc. in combination with other fibers other than sheath 102 in the piezoelectric fibers A, conductive the core unit 103 commingled etc. in combination with other fibers other than fibers B may be performed.
[0042]
　The length of the braided piezoelectric element composed of a sheath portion 102 of the core 103 and the braided piezoelectric fibers A conductive fibers B are not specifically limited. For example, the braided piezoelectric element is continuously produced in the manufacturing, it may be utilized to cut the length required for subsequent. The length of the braided piezoelectric element 1 mm ~ 10 m, preferably, 5 mm ~ 2m, more preferably from 1 cm ~ 1 m. The length is too short fiber shape convenience is lost, also would require emerges consider the resistance of the conductive fiber B is too long in length.
　Follows is a detailed description of each configuration.
[0043]
(Conductive fiber)
　as the conductive fibers B, as long as it exhibits conductivity, any known ones can be used. The conductive fibers B, for example, metal fibers, made of a conductive polymer fibers, carbon fibers, comprising a polymer obtained by dispersing conductive filler fibrous or granular fiber or conductive on the surface of the fibrous material, It includes fibers in which a layer having a. As a method for providing a layer having conductivity on the surface of the fibrous material is a metal coating, a conductive polymer coating, such as winding of the conductive fibers. Among these metal-coated conductive, durability, it preferred in view of flexibility. As a specific method of coating a metal, vapor deposition, sputtering, electrolytic plating, plating from the viewpoint of, but productivity such as electroless plating and the like are preferable. Such metal plated fibers may be referred to as a metal-plated fibers.
[0044]
　As the base of the fibers are coated with metal, a conductive can be a known fiber or without, for example, polyester fibers, nylon fibers, acrylic fibers, polyethylene fibers, polypropylene fibers, polyvinyl chloride fibers, aramid fibers, polysulfone fibers, polyether fibers, other synthetic fibers such as polyurethane fibers, it is possible to use cotton, hemp, natural fiber silk or the like, semisynthetic fibers acetate, etc., rayon, recycled fibers such as cupra. Based fiber is not intended to be limited to, can be used any known fibers, it may be used in combination of these fibers.
[0045]
　Metal coated on the base of the fibers shows a conductive, as long as the effect of the present invention may be either. For example, it is possible to use gold, silver, platinum, copper, nickel, tin, zinc, palladium, indium tin oxide, copper sulfide, and mixtures thereof and the like and alloys.
[0046]
　With organic fibers metal coated to the conductive fiber B with a bending resistance, it is much less conductive fibers break, excellent in durability and safety as a sensor using a piezoelectric element.
[0047]
　Conductive fibers B is also a multifilament bundled plurality of filaments, or may be a monofilament consisting of one filament. Write multifilament is preferred in view of the long stability of the electric characteristics. For monofilament (including spun yarn), the single yarn diameter is 1 [mu] m ~ 5000 .mu.m, preferably from 2 [mu] m ~ 100 [mu] m. More preferably from 3 [mu] m ~ 50 [mu] m. For multifilaments, the number of filaments is preferably one to 100,000 present, more preferably five-500, more preferably from ten to 100 present. However, the fineness-number of conductive fibers B, and fineness, the number of core 103 to be used in making the braid, also multifilament single conductive formed by a single plurality of yarns (monofilaments) It shall be counted as fiber B. Here, the core portion 103, even when using fibers other than the conductive fibers, the total amount of including it.
[0048]
　Handling decreases the intensity diameter of the fiber is small, it becomes difficult, also, flexibility is sacrificed if a larger diameter. It The sectional shape of the conductive fiber B is a circle or ellipse, is preferred in terms of design and manufacture of the piezoelectric element is not limited to this.
[0049]
　Moreover, since taking out efficiently electrical output from the piezoelectric polymer, low it is preferably an electric resistance, the volume resistivity of 10 -1 is preferably not more than Omega · cm, more preferably 10 -2 Omega · cm or less, more preferably 10 -3 or less Omega · cm. However, detection at sufficient resistivity intensity obtained for value, if the conductive fibers B of the electrical signal is not limited to this.
[0050]
　Conductive fibers B from application of the present invention, must be resistant to movement bending and twisting such iteration. As the indicator, knot strength, larger ones are preferred. Knot strength can be measured by JIS L1013 8.6 methods. The extent of proper knot strength to the present invention, is preferably 0.5 cN / dtex or more, more preferably 1.0 cN / dtex or more, still more preferably 1.5 cN / dtex or more , and most preferably 2.0 cN / dtex or more. As another index, flexural rigidity, smaller ones are preferred. Flexural stiffness, it is generally measured by the measuring device, such as a Kato Tech Co., Ltd. KES-FB2 pure bending tester. As the degree of suitable bending stiffness in the present invention, Toho Tenax Co., Ltd. Carbon Fiber "TENAX" (registered trademark) preferably small than HTS40-3K. Specifically, the bending rigidity of the conductive fiber × 10 0.05 -4 N · m 2 is preferably less / m, 0.02 × 10 -4 N · m 2 that is / m or less more preferably, 0.01 × 10 -4 N · m 2 and even more preferably less / m.

WE claims

[Requested item 1]
An oriented piezoelectric polymer structure was placed in a cylindrical or cylindrical body, the orientation angle of the piezoelectric polymer relative to the direction of the central axis of the cylindrical or columnar shaped piezoelectric polymer is disposed more than 15 ° and at 75 ° or less, the piezoelectric polymer comprises as a main component a crystalline polymer having an absolute value less 0.1pC / N or more 1000pC / N value of the piezoelectric constant d14 when the 3-axis alignment axis further wherein the piezoelectric polymer may include a P body the value of the piezoelectric constant d14 contains a positive crystalline polymer as a main component, and N containing the negative of the crystalline polymer as a main component, the structure the portion where the center axis has a length of 1 cm, the orientation axis Z twist direction mass ZP of the P body arranged by winding a helical orientation axes are arranged by winding a spiral S twist direction wherein the wound spiral mass of P body SP, the orientation axis Z lay direction The mass of the deployed the N body Te ZN, the mass of the N body orientation axis is arranged by winding a spiral S twist direction and SN, and the smaller of the (ZP + SN) and (SP + ZN) T1 , when the larger one and T2, the value of T1 / T2 is 0 to 0.8, structure.
[Requested item 2]
　The piezoelectric polymer comprises as a main component polylactic -L- acid or poly -D- acid structure of claim 1.
[Requested item 3]
　The piezoelectric polymer comprises a P comprising poly -D- acid as the main component, and an N body comprising poly -L- acid as the main component structure of claim 2.
[Requested item 4]
　When stretch deformed in a direction of the piezoelectric cylindrical polymer is disposed or cylindrical center axis of the given, charges of opposite polarity is generated in the central axis side and outer cylindrical shape or cylindrical, structure according to any one of claims 1 to 3.
[Requested item 5]
　The piezoelectric polymer is fibrous, those filamentary or tape-like, braided, twisted cord-like, and is constituted by a covering thread or pull aligned thread, to any one of claims 1 to 4, structure described.
[Requested item 6]
　The piezoelectric polymer constitutes only one closed area in a cross section perpendicular to the cylindrical or cylindrical central axis of the structure according to any one of claims 1-4.
[Requested item 7]
　Device comprising a structure according to any one of claims 1 to 6, the conductive body and disposed adjacent to the structure.
[Requested item 8]
　The piezoelectric polymer is arranged in a cylindrical and disposed the conductor to the position of the central axis of the cylindrical device of claim 7.
[Requested item 9]
　The conductor is made of conductive fibers, wherein the piezoelectric polymer is arranged to be assembled in a braided around the conductive fibers as a piezoelectric fiber device of claim 8.
[Requested item 10]
　The piezoelectric polymer is arranged the conductor on the outside of the deployed cylindrical or cylindrical device of claim 7.
[Requested item 11]
　The conductor is made of conductive fibers, wherein the piezoelectric polymer is a conductive fiber around the arranged cylindrical or cylindrical is arranged to be assembled in a braided device of claim 10.
[Requested item 12]
　An element according to any one of claims 7 to 11,
　depending on the charge generated when the elastic deformation in the direction of the central axis of the cylindrical or columnar shaped piezoelectric polymer is placed is given, the an output terminal for electric signal is output that occurs in the conductor,
　the sensor comprises an electrical circuit for detecting an electric signal which is output through the output terminal.
[Requested item 13]
　A core portion formed by the conductive fibers, the device according to claim 9, and a sheath formed by braided of the piezoelectric fibers so as to cover the core portion,
　of the sheath a conductive layer provided around
with a is the ratio d / Rc of the thickness d of the layer of piezoelectric fibers are 1.0 or more to the radius Rc of the core, braided piezoelectric element.
[Requested item 14]
　Wherein by the conductive layer sheath of coverage is 25% or more, braided piezoelectric element according to claim 13.
[Requested item 15]
　The conductive layer is formed by fibers, braided piezoelectric element according to claim 13 or 14.
[Requested item 16]
　Fabric-like piezoelectric element comprising a braided piezoelectric element according to any one of claims 13-15.
[Requested item 17]
　The fabric further includes an electrically conductive fibers in contact intersects the at least a portion of the braided piezoelectric element, the fabric-like piezoelectric element according to claim 16.
[Requested item 18]
　More than 30% of the fiber that intersects the fiber a is and the braided piezoelectric elements forming the fabric is conductive fiber, cloth-like piezoelectric element according to claim 17.
[Requested item 19]
　A braided piezoelectric element according to any one of claims 13-15,
　and amplifying means for amplifying the electric signal output from said braided piezoelectric element in response to applied pressure,
　is amplified by the amplifying means and output means for outputting an electrical signal,
　the device comprising a.
[Requested item 20]
　A cloth-like piezoelectric element according to claim 17 or 18,
　and amplifying means for amplifying the electric signal output from said fabric-like piezoelectric element in response to applied pressure,
　outputs an electric signal amplified by the amplifying means and output means for,
　the device comprising a.
[Requested item 21]
　A fabric-like piezoelectric element braided piezoelectric element is fixed to the fabric, the braided piezoelectric element,
　a core part formed by the conductive fibers, braided of the piezoelectric so as to cover the core portion the element of claim 9, and a sheath portion formed of fibers,
　a conductive layer provided on the periphery of the sheath
with a pullout strength per 5cm of the braided piezoelectric element with respect to the fabric is 0.1N or higher, cloth-like piezoelectric element.
[Requested item 22]
　Coverage of the braided piezoelectric element according to fibers constituting the cloth is higher than both sides least 30% of said fabric, cloth-like piezoelectric element according to claim 21.
[Requested item 23]
　Wherein the fabric braided piezoelectric element is fixed in a state or knitted state is woven, fabric-like piezoelectric element according to claim 21 or 22.
[Requested item 24]
　Wherein the layers of the double woven fabric or a double knit fabric braided piezoelectric element is sandwiched, fabric-like piezoelectric element according to claim 21 or 22.
[Requested item 25]
　Wherein is exposed the braided piezoelectric element partially from the fabric, the exposed said conductive fibers and / or the conductive layer of the output portion the braided piezoelectric element and the other member are electrically connected the fabric-like piezoelectric element according to any one of claims 21-24.
[Requested item 26]
　The coverage of the sheath by the conductive layer is 25% or more, fabric-like piezoelectric element according to any one of claims 21-25.
[Requested item 27]
　The conductive layer is formed by fibers, cloth-like piezoelectric element according to any one of claims 21 to 26.
[Requested item 28]
　The total fineness of the piezoelectric fibers, the conductive fibers total fineness 1 times or more of is 20 times or less, the fabric-like piezoelectric element according to any one of claims 21-27.
[Requested item 29]
　One per fineness of the piezoelectric fibers, the conductive fibers total fineness of 1/20 or more, it is 2 times or less, the fabric-like piezoelectric element according to any one of claims 21-28.
[Requested item 30]
　The fabric, at least a portion further comprises conductive fibers in contact to cross the fabric-like piezoelectric element according to any one of claims 21 to 29 wherein the braided piezoelectric element.
[Requested item 31]
　A cloth-like piezoelectric element according to any one of claims 21-30,
　and an electric circuit for detecting an electric signal output from said conductive fibers contained in the cloth-like piezoelectric element in response to applied pressure ,
　device comprising a.