JP4954109B2 - Resin sheet laminated metal plate for image scanner - Google Patents

Description

  The present invention relates to a resin sheet laminated metal plate for an image scanner in which a metal plate and a resin sheet are integrated.

  In recent years, acquisition, recording, storage, and the like of images as digital data have been promoted in various fields. For example, an attempt is made to construct a so-called digital archive by storing public documents, old documents, or art works as digital image data. Also, for example, in the medical field, recording of digital images of images obtained by various examinations is being promoted along with digitization of medical charts. At this time, in an inspection method in which an image (in this specification, “image” may be a latent image) is formed on a medium such as a film or an imaging plate, such as an X-ray transmission imaging method, In order to record as digital image data, it is necessary to scan the medium with an image scanner.

  In an image scanner, generally, a scanning mechanism for reading an image formed on a medium is housed inside the casing. For example, a medium inserted from an insertion port provided in the casing is transferred to the scanning mechanism. The image is read by a scanning mechanism after being transported inside. The medium from which the image has been read is conveyed again inside the apparatus and discharged from the discharge port, or after being erased from the latent image by an imaging plate or the like, it is accommodated in a cassette for reuse.

  Generally, a metal plate is used for the housing of the image scanner. However, when the housing is simply made of a metal plate, the inner wall of the housing and the medium come into contact with each other when the medium is transported inside the device, and the scratches are sized so as to affect image reading (for example, In some cases, scratches having a width of a few hundreds of μm or more in width are attached to the surface of the medium. In order to accurately read the image formed on the medium, it is desirable that the occurrence of such scratches be suppressed as much as possible. Particularly in the medical field, in order to prevent misdiagnosis and to make an accurate diagnosis, not only the surface on which the image is formed on the medium (for example, the photosensitive surface on the film) but also the opposite surface (that is, the image is formed). The occurrence of the scratch due to the contact with the inner wall of the housing must be suppressed as much as possible.

In order to suppress the occurrence of such scratches, it is conceivable to use a resin sheet laminated metal plate in which a metal plate and a resin sheet are integrated instead of a simple metal plate. As a conventional resin sheet laminated metal plate, for example, Patent Document 1 discloses a laminate in which the surface of a metal plate is coated with an ultrahigh molecular weight polyethylene resin.
JP 2001-205735 A

  However, the laminate disclosed in Patent Document 1 is premised on use as a sliding member having excellent self-sliding properties and self-abrasion resistance, and the surface of an article such as the medium in contact with the laminate is damaged. Is not considered at all. As will be described later, it is difficult to suppress the occurrence of the scratches on the surface of the medium in contact with the polyethylene sheet by simply covering the surface of the metal plate with an ultrahigh molecular weight polyethylene sheet.

  Therefore, the present invention affects the reading of an image formed on the medium (typically, a scratch on the surface of the object) even when the object to be scanned (typically the medium such as a film) comes into contact. It is an object of the present invention to provide a resin sheet laminated metal plate for an image scanner that can suppress the occurrence of scratches having a size such as that given.

  In the resin sheet laminated metal plate for an image scanner of the present invention, the metal plate and the ultra-high molecular weight polyethylene porous sheet are integrated so that the porous sheet is exposed, and measured by a Bowden-Leven type friction tester. The dynamic friction coefficient of the surface of the porous sheet is 0.20 or less.

  According to the present invention, a metal sheet and an ultrahigh molecular weight polyethylene porous sheet having a surface dynamic friction coefficient of a predetermined value or less are integrated into a resin sheet laminated metal sheet so that the porous sheet is exposed. Even when the scanning object (typically the medium such as a film) comes into contact, scratches on the surface of the object (typically affecting the reading of an image formed on the medium). Generation of size scratches) can be suppressed.

  The present invention will be described below with reference to the drawings.

  FIG. 1 is a cross-sectional view schematically showing an example of the resin sheet laminated metal plate of the present invention. A resin sheet laminated metal plate 1 shown in FIG. 1 has a structure in which a metal plate 2 and an ultrahigh molecular weight polyethylene porous sheet 3 are laminated and integrated so that one whole main surface of the porous sheet 3 is exposed. Have An adhesive layer 4 is disposed between the metal plate 2 and the porous sheet 3. The dynamic friction coefficient of the surface (exposed surface) of the porous sheet 3 measured by a Bowden-Lowen type friction tester is 0.20 or less (hereinafter, the dynamic friction coefficient measured by the friction tester is simply referred to as “dynamic friction coefficient”). Say).

  In such a resin sheet laminated metal plate 1, the resin sheet integrated with the metal plate 2 is a porous sheet 3 having a porous surface coefficient of dynamic friction of 0.20 or less. In particular, even when the medium such as a film) comes into contact, scratches on the surface of the object (typically scratches of a size that affects reading of an image formed on the medium) are generated. Can be suppressed. As will be described later in the examples, such an effect can be obtained by using a resin sheet integrated with a metal plate, an ordinary non-porous normal ultra-high molecular weight polyethylene sheet, or a porous sheet 3 generally having a dynamic friction coefficient on the surface. It cannot be obtained by using a fluororesin sheet such as polytetrafluoroethylene, which is considered to be as small as. In addition, in the fluororesin sheet, there is another problem that the fluororesin sheet is likely to be partially scraped when the object to be scanned comes into contact, and powdery foreign matter is likely to be generated. The fluororesin sheet is inferior in productivity as a resin sheet laminated metal plate as compared with an ultrahigh molecular weight polyethylene porous sheet, for example, a special surface treatment is required to be integrated with the metal plate.

  In addition, the resin sheet laminated metal plate 1 is suitable for, for example, a housing of an image scanner or a wall surface of a conveyance path of a scanning object in the image scanner because of the characteristics such as high strength and impact resistance of the metal plate 2. Can be used. When the housing (or the wall surface) of the image scanner is constituted by the resin sheet laminated metal plate 1, the porous sheet 3 faces the inside of the housing (on the side where the scanning object is transported in the transport path). By doing so, it is possible to suppress the occurrence of scratches on the surface of the object when the scan object is transported through the housing (on the transport path).

  In the resin sheet laminated metal plate 1 shown in FIG. 1, the entire one main surface (the main surface opposite to the main surface facing the metal plate 2) of the porous sheet 3 is exposed. As for the porous sheet in a sheet | seat laminated metal plate, the whole main surface does not necessarily need to be exposed. For example, when the casing of the image scanner is configured, at least a part of the surface of the porous sheet 3 is exposed, such as only a portion of the porous sheet that may be touched by the scan target is exposed. Just do it.

  The dynamic friction coefficient of the surface of the porous sheet 3 is preferably 0.18 or less. In this case, the generation of scratches on the surface of the scan target can be further suppressed. In addition, although the minimum of the said dynamic friction coefficient is not specifically limited, For example, it is about 0.10.

  The dynamic friction coefficient of the surface of the porous sheet 3 can be controlled, for example, by changing the average pore diameter, porosity, etc. of the porous sheet 3. In addition, when the metal plate 2 and the porous sheet 3 are integrated with each other, for example, when both are integrated by thermal lamination, the control can also be performed by changing the temperature or pressure of the thermal lamination. is there. Generally, when the temperature of the thermal laminate is raised (when the pressure is increased), the dynamic friction coefficient of the surface of the porous sheet 3 tends to increase.

  The lower limit of the thickness of the porous sheet 3 is not particularly limited, but 0.05 mm or more is preferable and 0.1 mm or more is more preferable in order to more reliably suppress the generation of scratches on the surface of the scan target. Moreover, although the upper limit of the thickness of the porous sheet 3 is not specifically limited, For example, it is good also as about 0.5 mm or about 0.3 mm. When the resin sheet laminated metal plate 1 is used for a housing, a conveyance path, etc. of an image scanner, it is usually necessary to deform to a predetermined shape, but when the thickness becomes excessively large, the resin sheet laminated metal plate 1 is deformed to the above shape. In some cases, the porous sheet 3 may peel from the metal plate 2.

  The thickness of the porous sheet 3 is preferably in the range of about 0.05 to 0.5 mm in consideration of the use as a housing of the image scanner.

  The average pore diameter of the porous sheet 3 is not particularly limited, but is usually about 10 to 100 μm, and preferably about 15 to 40 μm.

  Other characteristics (compression elastic modulus and Shore D) preferable as the porous sheet 3 are shown below. In addition, the porous sheet 3 does not necessarily satisfy the numerical ranges of both characteristics shown below.

The compression elastic modulus (compression elastic modulus in the direction perpendicular to the main surface) of the porous sheet 3 is preferably in the range of about 100 to 1000 kgf / cm ² (9.8 to 98 MPa), and 200 to 400 kgf / cm ² (19. The range of about 6-39.2 MPa) is more preferable. When the compression elastic modulus of the porous sheet 3 is in the above range, the generation of scratches on the surface of the scan target can be further suppressed. In addition, the compression elastic modulus of the porous sheet 3 is obtained by laminating three porous sheets having a thickness of 2 mm to form a multilayer body having a thickness of 6 mm, and then using the tensile and compression tester (Tensilon tester). Measure the stress generated when compressed at a constant speed in the direction perpendicular to the principal surface, the slope of the point indicating the maximum curvature in the curve drawn with the horizontal axis as time (compression amount) and the vertical axis as the measured stress Find it from

  Shore D indicating the hardness of the porous sheet 3 is preferably in the range of about 30 to 52, and more preferably in the range of about 35 to 46. When the Shore D of the porous sheet 3 is in the above range, the generation of scratches on the surface of the scan target can be further suppressed. The Shore D may be evaluated using a so-called Shore D hardness meter or a type D durometer defined in JIS K6253.

  The ultra high molecular weight polyethylene constituting the porous sheet 3 is preferably a polyethylene having a viscosity average molecular weight in the range of about 500,000 to 10,000,000, and more preferably a polyethylene having a molecular weight in the range of about 1,000,000 to 7,000,000.

  The ultrahigh molecular weight polyethylene porous sheet 3 can be formed from ultrahigh molecular weight polyethylene as a raw material based on a known method, for example, a method disclosed in JP-A-2-24129. In the method disclosed in the above publication, since the porous sheet is formed by sintering the ultra-high molecular weight polyethylene particles as a raw material without adding any additive, the porous sheet 3 having a low impurity content. It can be.

  As the ultra high molecular weight polyethylene used as a raw material, commercially available materials such as Hi-Zex Million manufactured by Mitsui Chemicals, Hostalen GUR manufactured by Ticona, and the like can be used.

  Moreover, as the porous sheet 3, you may use a commercially available ultra high molecular weight polyethylene porous sheet, for example, a sun map manufactured by Nitto Denko Corporation.

  The type of the metal plate 2 is not particularly limited, and may be a plate of various metals and alloys, for example, an iron plate such as a steel plate or an aluminum plate. Moreover, if necessary, a plating layer such as a zinc plating layer may be formed on the surface thereof.

  When the resin sheet laminated metal plate 1 is used as a housing of an electronic device, the metal plate 2 is preferably a galvanized steel plate. Commercial products such as JFE Excel Zinc (manufactured by JFE Steel) can be used for the galvanized steel sheet.

  The thickness of the metal plate 2 is not particularly limited, and may be appropriately selected according to the use of the resin sheet laminated metal plate 1. When the resin sheet laminated metal plate 1 is used as a housing of an image scanner, the thickness of the metal plate 2 is generally about 1 to 2 mm.

  In the resin sheet laminated metal plate of the present invention, the method for integrating the ultrahigh molecular weight polyethylene porous sheet and the metal plate is not particularly limited. However, as in the resin sheet laminated metal plate 1 shown in FIG. Therefore, it is preferable that the porous sheet 3 and the metal plate 2 are integrated. As described above, when the resin sheet laminated metal plate 1 is used for a housing of an image scanner or the like, usually, deformation to a predetermined shape is required, but the porous sheet 3 and the metal plate 2 are bonded to each other. In the case of being integrated via 4, it is possible to suppress both peeling at the time of deformation.

  The type of the adhesive layer 4 is not particularly limited, and may be a layer made of a hot melt adhesive, for example. In this case, the porous sheet 3 and the metal plate 2 can be integrated by a technique such as thermal lamination, and the resin sheet laminated metal plate 1 having excellent productivity can be obtained.

  In the case where the adhesive layer 4 is a layer made of a hot melt adhesive, it can be said that in the resin sheet laminated metal plate 1, the metal plate 2 and the porous sheet 3 are integrated via the hot melt adhesive.

  The type of hot melt adhesive is not particularly limited, and hot melt adhesives such as ethylene vinyl alcohol (EVA), polyimide, and polyolefin can be used.

  The structure of the resin sheet laminated metal plate of the present invention is not particularly limited as long as the metal plate and the ultrahigh molecular weight polyethylene porous sheet are integrated so that the porous sheet is exposed. For example, the resin sheet laminated metal plate provided with arbitrary layers other than a metal plate and the said porous sheet may be sufficient, and it does not specifically limit about the position where the said arbitrary layers are arrange | positioned.

  The part in which the resin sheet laminated metal plate of the present invention is used in the image scanner is not particularly limited. For example, as described above, the resin sheet laminated metal plate of the present invention can be suitably used for a housing and a wall surface of a conveyance path in which an object to be scanned is conveyed in an image scanner.

  The specific structure of the image scanner that can use the resin sheet laminated metal plate of the present invention is not particularly limited. The image scanner includes at least a scan mechanism that reads an image of a scan target (typically, an image formed on the medium such as a film). In addition to the mechanism, for example, a transport mechanism that transports the scan target is provided. You may have. When the image scanner includes a transport mechanism, the effect of using the resin sheet laminated metal plate of the present invention on the housing of the scanner or the wall surface of the transport path is increased.

  More specifically, an image scanner in which the resin sheet laminated metal plate of the present invention is used includes, for example, a housing provided with an insertion port for inserting a scanning object, and the image scanner that stores the image in the housing. A scanning mechanism for reading and a transport mechanism for transporting a scan object from the insertion port to the scan mechanism are provided.

  When the resin sheet laminated metal plate of the present invention is used for the housing of the image scanner, the resin sheet laminated metal plate is arranged so that the porous sheet in the resin sheet laminated metal plate of the present invention faces the inside of the housing. Good. When the resin sheet laminated metal plate of the present invention is used in the conveyance path of the scan object in the image scanner, the porous sheet in the resin sheet laminated metal plate of the present invention faces the side where the scan object is conveyed in the conveyance path. Thus, a resin sheet laminated metal plate may be disposed. By using the resin sheet laminated metal plate of the present invention in this way, even when a scan object (typically, the medium such as a film) comes into contact with the casing or the wall surface of the conveyance path, It is possible to suppress the occurrence of scratches on the surface (typically scratches having a size that affects reading of an image formed on the medium).

  The object to be scanned is not particularly limited, but the object is an article such as a photographic film, an X-ray film, or an imaging plate that is easily scratched on its surface and that the scratch easily affects the scan result. In addition, the effect of using the resin sheet laminated metal plate of the present invention for an image scanner is increased.

  Hereinafter, the present invention will be described in more detail with reference to examples. The present invention is not limited to the examples shown below.

  In this example, after laminating various resin sheets including an ultra-high molecular weight polyethylene porous sheet via a hot melt adhesive on the surface of a metal plate, the both are integrated by heat laminating to form a resin sheet laminated metal. A plate was prepared and its characteristics were evaluated.

  First, a method for producing a resin sheet laminated metal plate sample will be described.

-Sample 1-
After preparing a galvanized steel sheet (JFE Steel Corporation, JFE Excel Zinc: thickness 1 mm) as a metal plate, and applying a hot melt adhesive (Mitsui Chemicals Admer) with a thickness of 50 μm on the surface of the steel sheet, zinc Ultra high molecular weight polyethylene porous sheet (Sunmap manufactured by Nitto Denko Corporation: thickness 0.2 mm, average pore diameter 17 μm, compression modulus 350 kgf / cm ² , Shore D46) so as to sandwich the hot melt adhesive together with the plated steel sheet Arranged.

  Next, the temperature of the steel plate is raised to 200 ° C., and while applying force between the steel plate and the porous sheet (pressure 30 kgf / 600 mm width, linear velocity 0.5 m / min), both are heat laminated and integrated. Thus, a resin sheet laminated metal plate (Sample 1) was formed.

-Sample 2-
A resin sheet laminated metal plate (sample 2) was formed in the same manner as in sample 1, except that the temperature of the steel plate during heat lamination was 175 ° C.

-Sample 3-
A resin sheet laminated metal plate (sample 3) was formed in the same manner as in sample 1 except that the temperature of the steel plate during heat lamination was set to 150 ° C.

-Sample A (comparative example)-
A resin sheet laminated metal plate (sample A) as a comparative example was formed in the same manner as in sample 1, except that the temperature of the steel plate at the time of thermal lamination was 220 ° C.

-Sample B (comparative example)-
Resin which is a comparative example in the same manner as Sample 1, except that the temperature of the steel plate during heat lamination is 200 ° C. and the magnitude of the pressure applied between the steel plate and the porous sheet is 50 kgf / 600 mm width. A sheet laminated metal plate (Sample B) was formed.

-Sample C (comparative example)-
After preparing a galvanized steel sheet (JFE Steel Corporation, JFE Excel Zinc: thickness 1 mm) as a metal plate, and applying a hot melt adhesive (Mitsui Chemicals Admer) with a thickness of 50 μm on the surface of the steel sheet, zinc A non-porous ultra high molecular weight polyethylene sheet (Nitto Denko Corporation No. 440: thickness 0.2 mm) was placed so as to sandwich the hot melt adhesive together with the plated steel sheet.

  Next, the temperature of the steel plate is raised to 175 ° C., and both are heat laminated while applying a force between the steel plate and the ultrahigh molecular weight polyethylene sheet (pressure 30 kgf / 600 mm width, linear velocity 0.5 m / min). A resin sheet laminated metal plate (sample C) as a comparative example was formed.

-Sample D (comparative example)-
After preparing a galvanized steel sheet (JFE Steel Corporation, JFE Excel Zinc: thickness 1 mm) as a metal plate, and applying a hot melt adhesive (Mitsui Chemicals Admer) with a thickness of 50 μm on the surface of the steel sheet, zinc A polytetrafluoroethylene sheet (No. 900 manufactured by Nitto Denko Corporation: thickness 0.2 mm) whose surface adhesion was improved by a sputter etching process was disposed so as to sandwich the hot melt adhesive together with the plated steel sheet. When placing the polytetrafluoroethylene sheet, the sputter-etching surface and the hot melt adhesive were in contact with each other.

  Next, the temperature of the steel plate was raised to 175 ° C., and while applying a force between the steel plate and the polytetrafluoroethylene sheet (pressure 30 kgf / 600 mm width, linear velocity 0.5 m / min), both were thermally laminated. A resin sheet laminated metal plate (sample D) as a comparative example was formed by integration.

  Next, for each sample produced as described above, the coefficient of dynamic friction on the surface of the resin sheet (exposed surface: the entire main surface of one of the resin sheets is exposed for each sample), the resin sheet and the metal plate And the degree of scratches (damage characteristics) formed on the surface of the plate when the imaging plate was brought into contact with the resin sheet. The evaluation method for each of the above items is shown below.

(Dynamic friction coefficient of resin sheet surface)
The dynamic friction coefficient of the resin sheet surface was evaluated using a Bowden-Leven type friction tester. Specifically, a steel ball (10 mmφ) is used as the contact, the load applied to the contact is 200 gf, the sliding speed of the sample is 150 mm / min, and the value of the dynamic friction coefficient during the fifth sliding is measured. Value.

  Note that the Bowden-Leben type friction tester is a type of reciprocating friction tester, in which a sample is linearly brought into contact with a contact while applying a load to the surface of the measurement sample. It is an apparatus that measures the friction coefficient of the sample surface by measuring the stress generated in the contact at that time and causing the contact to slide.

(Adhesion between resin sheet and metal plate)
The degree of adhesion between the resin sheet and the metal plate was evaluated by Erichsen evaluation used for evaluating the adhesion strength of the coating film. The specific evaluation method was performed based on the Eriksen test method specified in JIS Z2247 using the Eriksen tester specified in JIS B7729. In addition, the indentation depth of the punch of the testing machine with respect to each sample was 6 mm.

  As a result of the evaluation by the above method, the case where the resin sheet was not peeled from the metal plate was “◯”, and the case where the resin sheet was peeled from the metal plate was “x”.

(Scratched properties)
First, each sample was deformed to form a casing 11 having a feed roller 14 as shown in FIG. The surface of the feed roller 14 is made of rubber, and is fixed to the housing 11 in a rotatable state by a rotating shaft 15 that passes through the central axis thereof. In FIG. 2, only two feed rollers 14 are depicted, but in reality, more feed rollers 14 are rotatable so that the imaging plate 16 can be moved to the back side or the near side of the paper surface. It is fixed to the housing 11 with

  When each sample was deformed, the resin sheet 13 was placed on the feed roller 14 side, that is, the imaging plate 16 side with respect to the metal plate 12. The distance between the resin sheet 13 and the imaging plate 16 (A shown in FIG. 2) was 2 mm.

  The commercially available imaging plate 16 is moved back and forth between the back side and the near side of the paper surface of FIG. 2 with respect to such a case 11, and scratches generated on the surface of the plate on the case 11 side. Was evaluated. Specifically, when the scratch having the largest width among the scratches generated on the surface of the plate 16 is seen, if the width is less than 20 μm (that is, a scratch having a width of 20 μm or more is formed). “◎”, “◯” when the width is in the range of 20 to 150 μm, and “◯” when the width exceeds 150 μm (that is, when a scratch exceeding 150 μm in width is formed). × ”. In evaluating the scratch characteristics, the photosensitive surface of the imaging plate 16 was set to be opposite to the casing 11.

  The evaluation results of the above items in each sample are shown in Table 1 below. Moreover, about the damage | wound characteristic, when the housing | casing 17 equivalent to the housing | casing 11 of FIG. 2 is formed using the metal plate (said galvanized steel plate) which has not laminated | stacked the resin sheet instead of the resin sheet laminated metal plate (FIG. 3, the evaluation result of the case 17 is made of the metal plate 12 is shown in Table 1 together with the sample E.

  As shown in Table 1, in samples 1 to 3 having a structure in which a metal plate and an ultra-high molecular weight polyethylene porous sheet are integrated, and the dynamic friction coefficient of the surface of the porous sheet is 0.20 or less, Compared with the other samples, it was possible to suppress the occurrence of scratches having a width exceeding 150 μm on the surface of the imaging plate 16.

  In Sample A where the temperature of the thermal laminate is high and Sample B where the pressure of the thermal laminate is high, the dynamic friction coefficient of the surface of the porous sheet is 0.25, which is larger than those of Samples 1 to 3.

  In sample D using a polytetrafluoroethylene sheet as the resin sheet, the resin sheet and the metal plate could be integrated, but the degree of adhesion between them was inferior to that of samples 1 to 3 and samples A to C. It was. In sample E in which the resin sheets were not laminated, the size of the scratch generated on the surface of the imaging plate 16 was the largest among all the samples.

  According to the present invention, even when a scanning object (typically, the medium such as a film) comes into contact, scratches on the surface of the object (typically affecting the reading of an image formed on the medium). It is possible to provide a resin sheet laminated metal plate for an image scanner that can suppress the occurrence of scratches having a size that gives a large amount of damage.

It is sectional drawing which shows typically an example of the resin sheet laminated metal plate for image scanners of this invention. In an Example, it is a schematic diagram which shows the structure of the housing | casing formed in order to evaluate the damage characteristic with respect to an imaging plate. In an Example, it is a schematic diagram which shows the structure of another housing | casing formed in order to evaluate the damage characteristic with respect to an imaging plate.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Resin sheet laminated metal plate 2 Metal plate 3 Ultra high molecular weight polyethylene porous sheet 4 Adhesive layer 11 Housing 12 Metal plate 13 Resin sheet 14 Feed roller 15 Rotating shaft 16 X-ray film 17 Housing

Claims (4)

The metal plate and the ultra high molecular weight polyethylene porous sheet are integrated so that the porous sheet is exposed,
A resin sheet laminated metal plate for an image scanner, wherein the dynamic friction coefficient of the surface of the porous sheet measured by a Bowden-Leven type friction tester is 0.20 or less.   The resin sheet laminated metal plate for an image scanner according to claim 1, wherein the dynamic friction coefficient is 0.18 or less.   The resin sheet laminated metal plate for an image scanner according to claim 1, wherein the thickness of the porous sheet is in a range of 0.05 to 0.5 mm.   The resin sheet laminated metal plate for an image scanner according to claim 1, wherein the metal plate and the porous sheet are integrated via a hot melt adhesive.

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