JP5258238B2 - Uneven sheet and pressure measuring method - Google Patents

Description

The present invention relates to a concavo-convex sheet and a pressure measurement method for performing pressure measurement using a pressure measurement material that develops color at a pressurization site.

  The material for pressure measurement is used for applications such as liquid crystal glass bonding, solder printing on printed circuit boards, and pressure adjustment between rollers. Such a material for pressure measurement includes, for example, a pressure measurement film represented by a prescale (trade name) provided by FUJIFILM Corporation.

  As an example of this pressure measurement film, a pressure measurement sheet using a color reaction between an electron donating colorless dye precursor and an electron accepting compound is disclosed (for example, see Patent Document 1), and 0.1 MPa to 20 MPa. It is said that it can be measured within a certain pressure range. The pressure measurement film has the characteristics that it can be used by cutting the film into an arbitrary size according to the measurement site, and, unlike so-called pressure-sensitive copying paper, which causes a color reaction due to high linear pressure due to writing pressure, It has the feature that pressure can be measured.

In recent years, the necessity of measuring the distribution of minute pressures has been increasing due to higher functionality and higher definition of products. For example, in the bonding of liquid crystal panels, the number of vacuum bonding methods increases as the area increases, and pressure distribution measurement in the region of atmospheric pressure of 0.1 MPa or less is important.
In solder printing on a printed circuit board, handling in a pressure region including a minute pressure of 0.1 MPa or less is increasing due to high definition of electronic components and multilayering of the substrate. There is a growing demand for accurate pressure distribution measurements.
In addition, fields that require minute pressure distribution measurement, such as pinching pressure measurement on transport rollers in the manufacturing process of copiers and printers, and pressing pressure measurement in polishing of silicon wafers in the semiconductor manufacturing process, are increasing. .

As a technique for measuring a minute pressure, a technique using a combination of the pressure measuring film and a surface plate having uniform fine irregularities on the surface (for example, see Patent Document 2), the pressure measuring film There is known a technique (for example, see Patent Documents 3 and 4) using a combination of a rubber elastic mat having a large number of convex portions on one side.
Japanese Patent Publication No.57-24852 JP-A-6-331467 JP-A-9-329513 Japanese Patent Laid-Open No. 10-62276

However, the technique using a surface plate having fine irregularities on the surface cannot be used for applications that require flexibility (flexibility) or thinness, such as pinching pressure measurement in a transport roller.
Also, in the technology using a rubber elastic mat having convex portions, the elastic mat itself acts as a cushion to relieve pressure distribution, especially in the bonding pressure measurement of a liquid crystal panel and the polishing process of a silicon wafer. It cannot be used for applications where thinness is required, such as pressure suppression measurement, and where accurate pressure distribution needs to be measured.

  The present invention has been made in view of the above, and an object thereof is to provide a concavo-convex sheet capable of measuring a minute pressure below a measurement lower limit of a pressure measurement material or a distribution thereof, and to achieve the object. To do.

The present inventor obtained knowledge that the problems can be solved by specifying the properties of the uneven sheet and the relationship between the pressure measurement material and the uneven sheet, and completed the present invention based on the knowledge.
That is, specific means for solving the above-described problems are as follows.

<1> As a color developer that develops a color by reacting with the color former and the material B having a color former layer containing a microcapsule containing an electron donating colorless dye precursor and a solvent as a color former. The material A having a developer layer containing the electron accepting compound is superimposed on the base material so that the surface of the color former layer and the surface of the developer layer face each other, and the pressure measurement lower limit is 0. A concavo-convex sheet for measuring pressure in a pressure range below the lower limit of pressure measurement, used together with a material for pressure measurement at 0.02 MPa to 0.05 MPa,
On a base portion having a thickness of 0.05 mm or more made of a hard resin having a Young's modulus of 500 MPa or more, a height of 0.1 mm to 0.3 mm made of a hard resin having a Young's modulus of 500 MPa or more having an exposed surface parallel to the base portion . It has a plurality of protrusions and has a total thickness of 0.5 mm or less.
The pressure of the pressure measurement material with respect to the pressure measurement lower limit when the area of the exposed surface is S, the interval between the plurality of convex portions is L, and pressure measurement is performed using both the uneven sheet and the pressure measurement material. When the ratio of the lower limit of measurement is R,
S = (L × L) / R
It is the uneven | corrugated sheet | seat characterized by satisfy | filling this relationship.

<2> The concavo-convex sheet according to <1>, wherein the convex portion has a cylindrical shape.
<3> The concavo-convex sheet according to <1>, wherein the shape of the convex portion is a shape obtained by cutting a cone whose bottom surface is in contact with the base portion by a plane parallel to the bottom surface.
<4> (a) The uneven sheet according to any one of <1> to <3>, wherein the uneven sheet is convex between the object to be measured and the pressure measurement material that develops color at the pressed part. (B) pressing the exposed surface parallel to the base of the convex portion against the pressure measuring material by pressurization, and placing the pressure measuring material on the pressure measuring material Forming a color development region having a density corresponding to the pressure by the convex portion, and (c) reading the color development region with a scanner to obtain a pressure, wherein the area of the exposed surface is S, and the plurality of convex portions When the interval between the parts is L, and the ratio of the pressure measurement lower limit of the pressure measurement material to the pressure measurement lower limit when the pressure measurement is performed using both the uneven sheet and the pressure measurement material is R,
S = (L × L) / R
It is the pressure measuring method characterized by satisfy | filling this relationship.

  The uneven | corrugated sheet | seat which can measure the micro pressure below the measurement lower limit of the material for pressure measurements, or its distribution can be provided.

The concavo-convex sheet of the present invention is an concavo-convex sheet for performing pressure measurement using with a pressure measurement material, and is an exposed surface parallel to the base portion on a base portion having a thickness of 0.05 mm or more made of a hard resin. A plurality of convex portions made of hard resin having a total thickness of 0.5 mm or less, an area of the exposed surface being S, an interval between the plurality of convex portions being L, the concavo-convex sheet and the pressure measuring material When the ratio of the pressure measurement lower limit of the pressure measurement material to the pressure measurement lower limit when pressure measurement is performed together with R is R,
S = (L × L) / R
It is configured to satisfy the relationship.

  By forming the concavo-convex sheet as described above, when pressure is applied between the object to be measured and the material for pressure measurement at a pressure measurement lower limit value specific to the material for pressure measurement, the pressure in the object to be measured The pressure is amplified about ((L × L) / S) times by the relationship between the area of the surface to which the pressure is applied and the area of the exposed surface where the pressure is concentrated. For this reason, even when the pressure applied between the object to be measured and the pressure measurement material is equal to or lower than the measurement lower limit specific to the pressure measurement material, the pressure value or the pressure distribution can be accurately measured. Especially suitable for pinching pressure measurement on transport rollers in copier or printer manufacturing process, laminating pressure measurement in glass substrate bonding in liquid crystal display manufacturing process, pressing pressure measurement in polishing silicon wafer in semiconductor manufacturing process, etc. is there.

In the present invention, the “interval between a plurality of convex portions” refers to the distance between the exposed surface center of a convex portion and the exposed surface center of another convex portion closest to the convex portion.
In the present invention, the “pressure measurement lower limit of the pressure measurement material” refers to the measurement lower limit when pressure measurement is performed with the pressure measurement material alone without using it together with the uneven sheet. The pressure measurement material has a specific measurement lower limit depending on its configuration, but when used in combination with the concavo-convex sheet of the present invention, the pressure measurement sensitivity becomes R times (that is, measurement specific to the pressure measurement material). Measurement of 1 / R of the lower limit value is possible). From the viewpoint of obtaining the effect of the present invention more effectively, the specific range of R is preferably 2 to 20, and more preferably 5 to 10.
Hereinafter, the ratio R of the pressure measurement lower limit of the pressure measurement material to the pressure measurement lower limit when the pressure measurement is performed using both the uneven sheet and the pressure measurement material may be referred to as “pressure amplification factor R”.

  The pressure range that can be measured by the pressure measurement method using the concavo-convex sheet of the present invention is preferably a range that is not more than the lower limit of measurement of the pressure measurement material used together. From the viewpoint of more effectively achieving the effects of the present invention, a range of 0.002 to 0.08 MPa is preferable, and a range of 0.004 to 0.04 MPa is more preferable.

The uneven sheet in the present invention has a plurality of convex portions made of hard resin having an exposed surface parallel to the base portion on the base portion having a thickness of 0.05 mm or more made of hard resin, and has a total thickness of 0.5 mm or less. Configured. Here, the total thickness is the sum of the thickness of the base portion and the height of the convex portion.
If the total thickness is greater than 0.5 mm, the uneven sheet may act as a cushion during pressure measurement, and accurate pressure distribution measurement may not be possible. From the viewpoint of more effectively achieving the effects of the present invention, the total thickness is preferably 0.05 mm to 0.4 mm, more preferably 0.07 mm to 0.3 mm.

The base portion needs to have a thickness of 0.05 mm or more from the viewpoint of ease of manufacture and ease of handling.
From the viewpoint of more effectively achieving the effects of the present invention, the thickness of the base portion is preferably 0.05 mm to 0.15 mm, more preferably 0.05 mm to 0.1 mm.

The shape of the convex portion is not particularly limited as long as it has an exposed surface parallel to the base portion. For example, the shape of the convex portion can be a cylindrical shape, a polygonal prism shape (triangular prism, quadrangular prism, etc.) ( For example, see FIGS. In addition, the side surface of the convex portion is not limited to the case where the side surface is perpendicular to the base portion, and the exposed surface area parallel to the base portion and the area of the surface in contact with the base portion may be different (for example, (See FIG. 2).
FIG. 1 is a perspective view showing an uneven sheet 10 according to the first embodiment. A cylindrical convex portion 14 is provided on the sheet-like base portion 12.
FIG. 2 is a perspective view showing the concavo-convex sheet 20 according to the second embodiment. On the sheet-like base portion 12, a convex portion 15 having a shape in which a cone whose bottom surface is in contact with the base portion is cut by a plane parallel to the bottom surface (hereinafter also referred to as “trapezoidal cylindrical shape”) is provided.
FIG. 3 is a perspective view showing an uneven sheet 30 according to the third embodiment. A quadrangular prism-shaped convex portion 16 is provided on the sheet-like base portion 12.
FIG. 4 is a perspective view showing an uneven sheet 40 according to the fourth embodiment. A triangular prism-shaped convex portion 17 is provided on the sheet-like base portion 12.

The base in the present invention is made of a hard resin.
In the present invention, the “hard resin” refers to a resin having a Young's modulus of 500 MPa or more.
The hard resin used for the base is preferably polyethylene terephthalate (PET), polyethylene, polystyrene, polypropylene, polycarbonate, acrylic, more preferably polyethylene terephthalate (PET), polycarbonate, acrylic, and particularly preferably polyethylene terephthalate (PET). .

The convex part in this invention consists of hard resin.
As hard resin used for a convex part, a hard thermoplastic resin and a hard UV curable resin are preferable, and a hard UV curable resin is more preferable.
As the hard thermoplastic resin, polycarbonate and hard acrylic are preferable, and hard acrylic is more preferable.
As the hard UV curable resin, an acrylic UV curable resin is preferable.
In the present invention, “UV” means ultraviolet (Ultra Violet).

It is preferable that the convex part in this invention is the hardness of the grade which does not deform | transform with a pressure from a viewpoint which show | plays the effect by this invention more effectively.
The Young's modulus of the convex portion is preferably 500 MPa or more, and more preferably 1000 MPa or more.
The parallel exposed surface at the base of the convex portion in the present invention, from the standpoint of demonstrating the effect of the invention more ^effectively, preferably 0.05 mm 2 to 20 mm ^2, more preferably 0.1 mm 2 to 5 mm ² .
The distance between the convex portions in the present invention is preferably 1 mm to 10 mm, more preferably 2 mm to 5 mm, from the viewpoint of more effectively achieving the effects of the present invention.
The height of the convex portion in the present invention is preferably 0.05 mm to 0.45 mm, more preferably 0.1 mm to 0.3 mm, from the viewpoint of more effectively achieving the effects of the present invention.
The density of the convex portions in the present invention is preferably 1 piece / mm ^{2 to} 100 pieces / mm ² from the viewpoint of more effectively achieving the effects of the present invention, and 4 pieces / mm ^{2 to} 25 pieces / mm ^2. More preferred.

<Method for producing uneven sheet>
The method for producing the concavo-convex sheet in the present invention is not particularly limited, a method for producing using a photolithography method, a method for producing using a hot press method, a method for producing using a pattern roll and a UV curable resin, etc. Various methods can be used.

  Among these, a method of manufacturing using a pattern roll and a UV curable resin is preferable from the viewpoint that the thickness of the uneven sheet can be reduced and formed uniformly. For example, a monomer solution that is a precursor of a UV curable resin is supplied between a pattern roll in which a reverse pattern (concave portion) of a convex portion of a concavo-convex sheet is formed on a surface and a base material that is continuously supplied. The supplied monomer solution is irradiated with UV light to form a convex portion made of UV curable resin on the substrate, and the convex portion formed by peeling the formed convex portion from the pattern roll to obtain a base material, Furthermore, the method of winding up this base material is suitable if necessary.

FIG. 5 is a cross-sectional view schematically showing the concavo-convex sheet manufacturing apparatus 60 used in the preferable manufacturing method.
The concavo-convex sheet manufacturing apparatus 60 includes a supply roller 22 that continuously supplies the base material 42 from the upstream side to the downstream side of the conveyance path that continuously conveys the base material 42 that serves as a base, and the supplied base material The transport roller 24, the transport roller 26, the transport roller 28, and the take-up roller 32 for winding up the base material 42 are configured to continuously transport 42. Further, a coating device 34 is provided at a position facing the transport roller 24 through the transport path of the base material 42 so that the monomer solution 36 that is a precursor of the UV curable resin can be applied onto the base material 42. It has become. Between the conveyance roller 26 and the conveyance roller 28, a cylindrical pattern roll 50 is provided. During this period, the base material 42 is deformed along the arc of the pattern roll 50, and the pattern roll rotates. It is designed to move together. The surface of the pattern roll 50 is provided with a concave portion 41 (in FIG. 5, only a portion of the concave portions is provided with a reference numeral 41 for convenience) which is a reverse pattern of the convex portion of the concavo-convex sheet to be manufactured. In addition, a UV light source 31 for curing the monomer solution 36 supplied on the substrate 42 is provided at a position facing the pattern roll 50 via the conveyance path of the substrate 42.

Next, a method for producing an uneven sheet using the uneven sheet manufacturing apparatus 60 will be described.
First, the base material 42 is continuously supplied by the supply roller 22, and the monomer solution 36 is continuously applied on the supplied base material 42 by the coating device 34.
The width of the base material 42 (the length in the direction orthogonal to the transport direction S) is preferably 200 mm to 2000 mm. The length of the base material 42 is preferably 100 m to 4000 m. The thickness of the base material 42 is preferably 50 μm to 450 μm. The conveyance speed is preferably 0.5 m / min to 50 m / min. Coating width of the monomer solution 36 is preferably 100Mm～1800mm, the coating amount of the monomer solution ^{36, 2ml / m 2 ~200ml / m} 2 is preferred.

The base material 42 to which the monomer solution 36 is applied is deformed along the arc of the pattern roll 50 that rotates in the rotation direction R after passing through the conveyance roller 26 and is conveyed in accordance with the rotation. At this time, the monomer solution 36 is filled between the recess 41 on the surface of the pattern roll 50 and the substrate 42.
Here, the rotation speed of the pattern roll 50 is preferably equal to the conveyance speed of the substrate 42. The diameter of the pattern roll 50 is preferably 100 mm to 500 mm, and the width of the pattern roll 50 is preferably 300 mm to 2200 mm.

Next, UV light (ultraviolet light) is irradiated from the UV light source 31 to the base material 42 and the monomer solution 36 that move in accordance with the rotation of the pattern roll 50, and the monomer solution 36 is cured to be made of a UV curable resin. The convex portion 44 is formed on the base material 42. UV irradiation dose at this ^{time, 100mJ / cm 2 ~2000mJ / cm} 2 is preferred.

Next, when the base material 42 passes the conveyance roller 28, the formed convex portion 44 is peeled off from the pattern roll 50. The base material 42 on which the convex portions 44 are formed is taken up by the take-up roller 32.
The wound base material 42 with the convex portion 44 is cut into an appropriate size according to the application and used as an uneven sheet.
In addition, although the case where the convex part 44 is cylindrical shape is represented in FIG. 5, the shape of the convex part of the uneven | corrugated sheet which can be manufactured with the manufacturing method of the said uneven sheet | seat is not restricted to a cylindrical shape. For example, by appropriately changing the shape of the concave portion on the surface of the pattern roll 50, the convex portion can be formed in other shapes such as the trapezoidal cylindrical shape, the triangular prism shape, and the quadrangular prism shape described above.

<Pressure measurement method>
Here, although the example of embodiment of the pressure measuring method using the uneven | corrugated sheet | seat of this invention is demonstrated, it is not limited to the following embodiment.
The pressure measurement method in this embodiment is:
(A) The above-described uneven sheet of the present invention is disposed between the object to be measured and the pressure measurement material that develops a color at the pressurization site in a direction in which the convex portion of the uneven sheet is on the pressure measurement material side. Process,
(B) pressing the exposed surface parallel to the base of the convex portion to the pressure measurement material by pressurization and forming a color development region having a density corresponding to the pressure by the convex portion on the pressure measurement material;
(C) reading the color development area with a scanner to obtain pressure;
Have
The pressure of the pressure measurement material with respect to the pressure measurement lower limit when the area of the exposed surface is S, the interval between the plurality of convex portions is L, and pressure measurement is performed using both the uneven sheet and the pressure measurement material. When the ratio of the lower limit of measurement is R,
S = (L × L) / R
It is configured to satisfy the relationship.

  When the pressure measurement method is configured as described above, when pressure is applied between the object to be measured and the pressure measurement material at the measurement lower limit value of the pressure measurement material, the pressure is about ((L × L ) / S) times amplified. For this reason, even when the pressure applied between the object to be measured and the pressure measurement material is equal to or lower than the measurement lower limit specific to the pressure measurement material, the pressure value or the pressure distribution can be accurately measured.

<(A) Process>
In the step (a), the concavo-convex sheet according to the present invention is disposed between the object to be measured and the pressure measurement material that develops the pressurizing portion in a direction in which the convex portion of the concavo-convex sheet is on the pressure measurement material side. It is a process to do.
There are no particular limitations on the object to be measured, and liquid crystal panels, glass substrates, silicon wafers, printed substrates, and transfer rollers for copying machines and printers can be used.

<(B) Process>
In the step (b), an exposed surface parallel to the base of the convex portion is pressed against the pressure measuring material by pressurization, and a color developing region having a density corresponding to the pressure by the convex portion is formed on the pressure measuring material. It is a process to do.

Here, with reference to FIG. 6A, FIG. 6B, FIG. 7A, FIG. 7B, FIG. 8A, and FIG. explain.
6 (A), 7 (A), and 8 (A) are diagrams conceptually showing a state of pressurization in one embodiment of the present invention. In FIG. 6A, FIG. 7A, and FIG. 8A, a pressure measuring material 64 is disposed between the measured object 61 and the measured object 62, and further, the measured object 62 and the pressure are measured. Between the measurement material 64, the concavo-convex sheet 70 is arranged in such a direction that the convex portion 74 is on the pressure measurement material 64 side. The pressure applied between the DUT 61 and the DUT 62 (in FIGS. 6 to 8, pressure is applied from each side with a pressure P) is concentrated on the convex portion of the concave and convex sheet, and the pressure on the convex portion. A color development region 68 having a color density corresponding to the above is formed in the pressure measurement material 64. The pressure measuring material 64 in the above embodiment is a two-sheet type, which will be described later, and an electron donating colorless dye sheet 64A in which a coloring layer is provided on a substrate, and a developer layer on a substrate. The developer sheet 64 </ b> C thus formed is superposed so that the color-developing layer and the developer layer are in contact with each other.

6A is a cross-sectional view conceptually showing a state at low pressure, and FIG. 6B is a plan view conceptually showing the pressure measurement material in FIG. 6A. As shown in FIGS. 6A and 6B, the pressure applied to the convex portion 74 is low, and the color density of the coloring region 68 is low.
FIG. 7A is a cross-sectional view conceptually showing a state at an intermediate pressure, and FIG. 7B is a plan view conceptually showing the pressure measurement material in FIG. 7A. . As shown in FIGS. 7A and 7B, the pressure applied to the convex portion 74 is higher than that at the time of low pressure, and the color density of the coloring region 68 is high.
8A is a cross-sectional view conceptually showing a state at high pressure, and FIG. 8B is a plan view conceptually showing the pressure measurement material in FIG. 8A. As shown in FIGS. 8A and 8B, the pressure applied to the convex portion 74 is further increased as compared with the case of the intermediate pressure, and the color density of the coloring region 68 is further increased.
Note that the deformation amount of the convex portion 74 does not change (preferably, it does not deform by pressurization) through the low pressure, the medium pressure, and the high pressure, and the area itself of the color development region 68 does not change.

  Note that the pressurization in the present invention is not limited to the above-described embodiment, and for example, either one of the measurement object 61 and the measurement object 62 may be fixed and the pressure may be applied only from the other. In addition, as a material for pressure measurement, materials other than the above-described two-sheet type such as a mono-sheet type pressure measurement sheet can be used. Moreover, the number (density) of the convex part provided in the uneven | corrugated sheet | seat can be set suitably.

<(C) Process>
The step (c) in the present invention is a step of obtaining the pressure by reading the color development region with a scanner.
As the scanner, for example, a scanner that moves the line sensor along the pressure measurement material, a scanner that uses a two-dimensional CCD area sensor, or the like can be used.
The method for obtaining the pressure is not particularly limited.For example, based on the relationship between the color density of the color development area obtained in advance and the pressure, a method for converting the color density of the read color development area into a pressure value, etc. Can be used. Further, the pressure distribution can be obtained by connecting the positions where the pressures are equal to each other and performing multidimensional display. Further, the average pressure applied to the object to be measured can be obtained based on the ratio between the total area of the read color developing regions and the area where the pressure is actually applied to the object to be measured.

Here, although preferable embodiment of (c) process is described with reference to FIGS. 9-11, this invention is not limited to this form. In this embodiment, the color density of each color-development region is read by a scanner, the pressure applied by the convex portion is obtained, and the distribution of the pressure is displayed in a multidimensional manner by connecting positions where the pressure is equal.
FIG. 9 is a plan view showing an example of the pressure measurement material after the step (b), and FIG. 10 is a diagram conceptually showing the configuration of the pressure image analyzer, and FIG. FIG. 11 is a diagram two-dimensionally showing the pressure measurement result, and FIG. 11B is the pressure measurement result along the line AA in FIG. 11A.

In FIG. 9, a plurality of color development regions 68 having various color densities corresponding to the pressing pressure by the convex portions are formed on the pressure measurement material 64 which is a pressure measurement material (in FIG. 9, some color development regions are shown). Only 68 is attached).
In the pressure image analyzing apparatus 100 shown in FIG. 10, a scanner 80 for reading a color development area, a microcomputer 82 for calculating pressure and pressure distribution from the read color development area, and a multi-dimensional display of the obtained pressure and pressure distribution. And a dimension display means 94.

The image of the color development region 68 (pressing point) of the pressure measurement material 64 shown in FIG. 9 is read by the scanner 80 shown in FIG.
The output of the scanner 80 is input to the microcomputer 82. The microcomputer 82 has various functions configured by software. The pressurization point reading means 84 takes in the output of the scanner 80 and obtains the coordinate position and color density of each color development region 68. The pressure detecting means 86 calculates a pressure P ₀ corresponding to this color density. That is, a conversion table, map, or conversion formula for calculating the conversion of the pressure P ₀ corresponding to each color density is stored in advance in the look-up table (LUT) 88, and the pressure detection unit 86 uses the LUT 88 to calculate the pressure P _0. Is calculated.

The equal pressure distribution calculating means 90 obtains the pressure distribution by connecting the positions where the pressures using the pressure P ₀ of the coloring area 68 become equal. That is, when the color development region 68 is positioned on a lattice having a constant interval as shown in FIG. 11A, the distribution is shown with the pressure P ₀ of the color development region 68 on the AA line as the vertical axis. 11 (B). In FIG. 11 (A), a pressing point with a large color density and a high pressing pressure in the color development region is represented by a plot with a large radius, and a pressing point with a low color density and a low pressing pressure is represented by a plot with a small radius. Yes.

In FIG. 11 (B), P ₁ , P ₂ , P ₃ , P ₄ ,... Indicate the pressures at the pressurization points Q ₁ , Q ₂ , Q ₃ , Q ₄ ,. Show. In the equal pressure distribution calculating means 90, a smooth curve connecting the points P ₁ , P ₂ , P ₃ , P ₄ ,... Is obtained by using, for example, a mathematical interpolation method. Various methods can be used as the interpolation method. For example, a method of obtaining a polynomial or a multidimensional curve connecting a certain number of points P ₁ , P ₂ , P ₃ , P ₄ ,.

Using the pressure curve thus obtained, the equal pressure distribution calculating means 90 obtains coordinates R _a , R _b , and R _c that become predetermined constant pressures (set pressures) P _a , P _b , and P _c . More operations the A-A line and another line B-B, repeated for grid lines, such as line C-C, by connecting the coordinate R _a becomes set pressure P _a, FIG. 11 (A) it can be obtained an equal pressure line S _a shown in. Similarly, the equal pressure lines S _b and S _c can be obtained by connecting the coordinates R _b and R _c which become the set pressures P _b and P _c .

Here, the setting pressures P _a , P _b , and P _c can be arbitrarily changed by the setting changing means 92. By changing the set pressures P _a , P _b , P _c ,..., The positions and intervals of the isobaric lines S _a , S _b , S _c shown in FIG. It is convenient to specify.

The isobars S _a , S _b , and S _c thus obtained are output by the multidimensional display means 94. For example, the isobaric lines S _a , S _b , and S _c shown in FIG. 11A are printed out or displayed as an image by a printer or CRT. Color display may be performed by changing the display color for each predetermined pressure range indicated by the isobaric lines S _a , S _b , and S _c . Further, the pressure may be displayed three-dimensionally in the height direction.

  As a result, the color development region 68 of the pressure measuring material 64 appearing in a lattice shape can be changed to a pressure distribution that is continuously displayed in two dimensions or in multiple dimensions. Therefore, the pressure distribution can be immediately known visually, and handling becomes extremely simple.

<Material for pressure measurement>
Next, the pressure measurement material used with the uneven | corrugated sheet | seat of this invention is demonstrated.
The pressure measuring material is an electron accepting colorless dye precursor (hereinafter also referred to as “coloring agent”) and a microcapsule encapsulating a solvent, and an electron accepting property that reacts with the electron donating colorless dye precursor to cause color development. The compound (hereinafter also referred to as “developer”) is preferably formed by providing (preferably coating) a single substrate or a separate substrate.

  In the case of the so-called mono-sheet type, in which the material for pressure measurement in the present invention is a so-called mono-sheet type in which the microcapsules and the electron-accepting compound are provided on a single substrate, the substrate and the substrate A developer-containing developer layer and a microcapsule-containing color developer layer, which are provided in this order from the substrate side, are placed on the material, and are sandwiched between the parts where pressure or pressure distribution is to be measured. Pressurize with.

  In the case of the so-called two-sheet type in which the material for pressure measurement in the present invention is provided by coating the microcapsule and the electron-accepting compound on separate substrates, on the substrate such as a sheet or a film. A material A having a developer layer containing a developer and a material B having a microcapsule-containing color former layer on a substrate such as a sheet or a film. Both materials are stacked so that the surface where the colorant is present (color developer layer surface) and the surface where the electron accepting compound of material A is present (color developer layer surface) face each other. Apply pressure between the parts to be measured.

By pressurizing as described above, the microcapsule is broken and the inclusion containing the electron donating colorless dye precursor is released, and the electron donating colorless dye precursor and the electron accepting compound react to color. Is seen. At this time, the inclusion containing the electron-donating colorless dye precursor is released more in response to the pressure applied, and the amount of reaction with the electron-accepting compound increases, so that deep color development is obtained.
Among the above, from the viewpoint of storage stability and handleability, the pressure measurement material is prepared by coating the microcapsules enclosing the electron-donating colorless dye precursor and the electron-accepting compound on separate substrates. It is more preferable that the two-sheet type is provided.

  The material for pressure measurement in the present invention is colored before and after pressurization at 0.05 MPa from the viewpoint of obtaining a concentration that can be read with a very small pressure (especially a pressure of less than 0.1 MPa (preferably surface pressure)). The density difference ΔD is preferably 0.02 or more.

(Base material)
The substrate constituting the pressure measurement material in the present invention may be any of a sheet shape, a film shape, a plate shape, and the like, and specific examples include paper, plastic film, synthetic paper and the like. The same is true regardless of whether the pressure measurement material is in the mono-sheet type or the two-sheet type.

Specific examples of the paper include high-quality paper, medium-quality paper, reprint paper, neutral paper, acid paper, recycled paper, coated paper, machine-coated paper, art paper, cast-coated paper, fine-coated paper, and tracing paper. And recycled paper. Specific examples of the plastic film include a polyester film such as a polyethylene terephthalate film, a cellulose derivative film such as cellulose triacetate, a polyolefin film such as polypropylene and polyethylene, and a polystyrene film.
In addition, specific examples of the synthetic paper include polypropylene and polyethylene terephthalate biaxially stretched to form a large number of microvoids (such as Yupo), and those made of synthetic fibers such as polyethylene, polypropylene, polyethylene terephthalate, and polyamide, The thing which laminated | stacked these on a part of paper, one surface, both surfaces, etc. are mentioned. However, the present invention is not limited to these.
Among these, a plastic film and synthetic paper are preferable, and a plastic film is more preferable in that the color density generated by pressurization is higher.

(Electron-donating colorless dye precursor)
In the present invention, the microcapsules contained in the color former layer of the pressure measuring material preferably include at least one electron donating colorless dye precursor.
As the electron-donating colorless dye precursor that can be encapsulated in the microcapsule, a known one can be used for the application of pressure-sensitive copying paper or heat-sensitive recording paper. For example, triphenylmethane phthalide compound, fluorane compound, phenothiazine compound, indolyl phthalide compound, leucooramine compound, rhodamine lactam compound, triphenylmethane compound, diphenylmethane compound, triazene compound, Various compounds such as spiropyran compounds and fluorene compounds can be used.
Details of these compounds are described in JP-A-5-257272, and the electron-donating colorless dye precursor can be used alone or in combination of two or more.

The electron-donating colorless dye precursor enhances color developability at a pressure (preferably surface pressure) of less than 0.1 MPa, and obtains a high concentration at a slight pressure (enhances a concentration change (concentration gradient) with respect to a pressure change). Therefore, those having a high molar extinction coefficient (ε) are preferable. The molar extinction coefficient (ε) of the electron-donating colorless dye precursor is preferably 10000 mol ⁻¹ · cm ⁻¹ · L or more, more preferably 15000 mol ⁻¹ · cm ⁻¹ · L or more, Further, it is preferably 25000 mol ⁻¹ · cm ⁻¹ · L or more.

  Preferable examples of the electron donating colorless dye precursor having ε in the above range include 3- (4-diethylamino-2-ethoxyphenyl) -3- (1-ethyl-2-methylindol-3-yl) -4- Azaphthalide (ε = 61000), 3- (4-diethylamino-2-ethoxyphenyl) -3- (1-n-octyl-2-methylindol-3-yl) phthalide (ε = 40000), 3- [2, 2-bis (1-ethyl-2-methylindol-3-yl) vinyl] -3- (4-diethylaminophenyl) -phthalide (ε = 40000), 9- [ethyl (3-methylbutyl) amino] spiro [12H -Benzo [a] xanthene-12,1 '(3'H) isobenzofuran] -3'-one (ε = 34000), 2-anilino-6-dibutylamino-3-methylfluor Run (ε = 22000), 6-diethylamino-3-methyl-2- (2,6-xylidino) -fluorane (ε = 19000), 2- (2-chloroanilino) -6-dibutylaminofluorane (ε = 21000) ), 3,3-bis (4-dimethylaminophenyl) -6-dimethylaminophthalide (ε = 16000), 2-anilino-6-diethylamino-3-methylfluorane (ε = 16000), and the like.

When the molar extinction coefficient ε is used alone as an electron donating colorless dye precursor in the above range, or when the molar extinction coefficient ε is used in combination of two or more containing an electron donating colorless dye precursor in the above range, The ratio of the electron donating colorless dye precursor having a molar extinction coefficient ε of 10,000 mol ⁻¹ · cm ⁻¹ · L or more to the total amount of the electron donating colorless dye precursor is less than 0.1 MPa (preferably From the viewpoint of improving color developability at (surface pressure) and obtaining a high concentration at low pressure (increasing concentration change (concentration gradient) with respect to pressure change), the range of 10 to 100% by mass is preferable, and the range of 20 to 100% by mass is preferable. More preferably, the range of 30-100 mass% is more preferable.
When two or more kinds of electron-donating colorless dye precursors are used, it is preferable to use two or more kinds each having an ε of 10,000 mol ⁻¹ · cm ⁻¹ · L or more.

The molar extinction coefficient (ε) can be calculated from the absorbance when an electron-donating colorless dye is dissolved in a 95% aqueous acetic acid solution. Specifically, in a 95% acetic acid aqueous solution of an electron donating colorless dye whose concentration is adjusted so that the absorbance is 1.0 or less, the measurement cell length is Acm, and the electron donating colorless dye concentration is B mol. / L, where the absorbance is C, it can be calculated by the following formula.
Molar extinction coefficient (ε) = C / (A × B)

The amount of the electron-donating colorless dye precursor (for example, the coating amount) is 0.1 to 5 g / m ² in terms of the mass after drying from the viewpoint of enhancing the color developability at a low pressure (preferably less than 0.1 MPa). Is preferably 0.1 to 4 g / m ² , and more preferably 0.2 to 3 g / m ² .

(solvent)
The microcapsules in the present invention preferably include at least one kind of solvent together with the electron donating colorless dye precursor.
As the solvent included in the microcapsule, a known solvent can be used for pressure-sensitive copying paper. For example, alkylnaphthalenes such as diisopropylnaphthalene, diarylalkanes such as 1-phenyl-1-xylylethane, alkylbiphenyls such as isopropylbiphenyl, other triarylmethanes, alkylbenzenes, benzylnaphthalenes, diarylalkylenes, arylindanes Aromatic hydrocarbons such as dibutyl phthalate, isoparaffins, etc., natural oils such as soybean oil, corn oil, cottonseed oil, rapeseed oil, olive oil, coconut oil, castor oil, fish oil, and mineral oils And high boiling point fractions. You may use a solvent individually by 1 type or in mixture of 2 or more types.

  If necessary, a solvent having a boiling point of 130 ° C. or lower, such as ketones such as methyl ethyl ketone, esters such as ethyl acetate, alcohols such as isopropyl alcohol, and the like can be added as an auxiliary solvent.

(Method for producing microcapsules)
The microcapsules encapsulating the electron-donating colorless dye precursor and the solvent can be obtained by any method known per se, such as interfacial polymerization method, internal polymerization method, phase separation method, external polymerization method, coacervation method, etc. Can be manufactured.

  The wall material of the microcapsule is particularly limited from the water-insoluble and oil-insoluble polymers conventionally used as the wall material of the microcapsule containing the electron donating colorless dye precursor of the pressure-sensitive recording material. Can be used without Among these, urethane / urea resin (polyurethane / urea), melamine / formaldehyde resin, and gelatin are preferable as the wall material. From the viewpoint of obtaining good color at low pressure (preferably less than 0.1 MPa), polyurethane / urea, A formaldehyde resin is more preferable, and a polyurethane / urea containing a urethane bond is particularly preferable.

Here, a case where polyurethane / urea is used will be described as an example.
The preparation of a dispersion of polyurethane-urea wall microcapsules encapsulating an electron-donating colorless dye precursor can be carried out using a known method in pressure-sensitive copying paper applications. For example, a solution (oil phase) obtained by dissolving an electron-donating colorless dye precursor and a polyvalent isocyanate in a solvent is used as a hydrophilic solution (for example, a capsule wall-forming substance such as a polyol or polyamine). There is a method of emulsifying and dispersing in water or the like; aqueous phase), and coating the oil droplets in the obtained emulsified dispersion with polyurethane / urea to form microcapsules. At this time, by heating, the polymer formation reaction proceeds at the oil droplet interface, and the microcapsule wall can be formed.

  During the process of microencapsulation, a reaction modifier such as a polyvalent hydroxy compound and a polyvalent amine may be added. Specific examples of the polyvalent hydroxy compound include aliphatic or aromatic polyhydric alcohols, hydroxy polyesters, hydroxy polyalkylene ethers, alkylene oxide adducts of polyvalent amines, and the like. Among them, aliphatic or aromatic polyhydric alcohols and alkylene oxide adducts of polyvalent amines are preferable, and alkylene oxide adducts of polyvalent amines are more preferable.

Any polyvalent amine may be used as long as it has _two or more —NH groups or —NH ₂ groups in the molecule. Specific examples of the compound include aliphatic polyamines such as diethylenetriamine, triethylenetetramine, 1,3-propylenediamine, and hexamethylenediamine; epoxy compound adducts of aliphatic polyamines; alicyclic compounds such as piperazine Examples include polyvalent amines; heterocyclic diamines such as 3,9-bis-aminopropyl-2,4,8,10-tetraoxaspiro- (5,5) undecane, and the like.

  The amount of polyhydric hydroxy compound or polyamine added is appropriately determined depending on the type and amount of polyisocyanate used and the desired capsule membrane hardness. In the case of adding a polyvalent hydroxy compound or a polyvalent amine, the ratio (mass ratio) of “total amount of polyvalent hydroxy compound and / or polyvalent amine: amount of polyvalent isocyanate” is 0.1: 99.9-30. : 70 is preferable, and 1:99 to 25:75 is more preferable. Further, the addition amount of the polyvalent hydroxy compound is preferably 99.9: 0.1 to 70:30, and 99: 1 to 75:25 in terms of mass ratio of polyvalent isocyanate: polyvalent hydroxy compound. More preferably, it is more preferably 98: 2 to 80:20.

  The addition timing of the polyvalent hydroxy compound or polyvalent amine may be added in advance to the solvent or auxiliary solvent for dissolving the electron donating colorless dye precursor, or may be added before or after emulsification dispersion. Good.

  In the hydrophilic solution, as an emulsifier, various amphoteric polymers, ionic polymers, nonionic polymers such as gelatin, starch, carboxymethyl cellulose, polyvinyl alcohol, polyalkylbenzene sulfonate, polyoxyethylene sulfate, A polyoxyalkyl ether, a modified product thereof, an isobutylene-maleic anhydride copolymer, or the like may be added.

  As the polyvalent isocyanate, those known for pressure-sensitive copying paper can be used. For example, an isocyanurate of hydrogenated xylylene diisocyanate (generally referred to as hydrogenated XDI), an isocyanurate of isophorone diisocyanate (generally referred to as IPDI), 4,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate and trimethylene Adducts with methylolpropane, hexamethylene diisocyanate burette, hexamethylene diisocyanate isocyanurate, hexamethylene diisocyanate isocyanurate compound bonded with aliphatic diol (eg, alkylene diol) by urethane bond, polymethylene poly Phenyl isocyanate, carbodiimide-modified diphenylmethane diisocyanate, adduct of tolylene diisocyanate and trimethylol propane, xylylene di Adduct of socyanate and trimethylolpropane, isocyanurate of tolylene diisocyanate, adduct of hydrogenated xylylene diisocyanate and trimethylol propane, adduct of isophorone diisocyanate and trimethylol propane, xylylene diisocyanate And a tris- (p-isocyanatophenyl) thiophosphite. Polyvalent isocyanate can be used individually by 1 type or in mixture of 2 or more types.

  In addition to the above electron-donating colorless dye precursor, solvent, and auxiliary solvent, the microcapsule may contain an additive as necessary. Examples of the additive include an ultraviolet absorber, a light stabilizer, an antioxidant, a wax, and an odor inhibitor.

  The mass ratio between the solvent encapsulated in the microcapsule and the electron donating dye precursor (solvent: precursor) is preferably in the range of 98: 2 to 30:70, and 97: 3 to 40 in terms of color developability. : 60 is more preferable, and 95: 5 to 50:50 is more preferable.

  The wall thickness of the capsule wall of the microcapsule depends on various conditions such as the type of capsule wall material and the capsule diameter, but is not limited as long as it can be broken by a slight pressure (at least 0.05 MPa). Can be arbitrarily selected. Among these, from the viewpoint of obtaining good color developability at a low pressure of less than 0.1 MPa, the preferable wall thickness is in the range of 0.005 to 2.0 μm, more preferably in the range of 0.05 to 0.30 μm. Preferably, it is 0.06-0.28 μm when the median diameter A of the microcapsule is 10-40 μm. The wall thickness of the capsule wall is particularly preferably 0.07 to 0.27 μm when the capsule wall of a microcapsule having a median diameter A of 10 to 40 μm is made of polyurethane urea.

The microcapsule encapsulating the electron-donating colorless dye precursor is formed using polyurethane / urea containing a urethane bond as a wall material and satisfying the relationship shown in the following formula 1 at a low pressure (preferably less than 0.1 MPa). And particularly preferable in terms of obtaining good color development. By forming a microcapsule that satisfies this relational expression, it is possible to form a coloring system that easily develops color even under pressure in a low pressure region (preferably a pressure region of less than 0.1 MPa). In the following formula 1, δ represents the number average wall thickness (μm) of the macrocapsules, and D represents the median diameter (μm) of the volume standard of the microcapsules.
1.0 × 10 ⁻³ ≦ δ / D ≦ 2.0 × 10 ⁻² Formula 1
When the δ / D value is within the above range, the balance between the capsule size and the capsule wall thickness is good, the capsule content does not leak over time, and the capsule content does not leak over time. Good color development can be obtained in the region).

  In the present invention, the wall thickness refers to the thickness of a resin film (so-called capsule wall) that forms capsule particles of microcapsules, and the number average wall thickness (μm) refers to the individual capsule walls of five microcapsules. An average value obtained by obtaining the thickness with a scanning electron microscope and averaging it.

Of the above-mentioned range of δ / D value, the δ / D value is 2.0 × 10 ⁻³ to in view of obtaining good color (coloring) in a low pressure region (preferably a pressure region of 0.1 MPa or less). 1.5 × 10 ⁻² is preferable, and 3.0 × 10 ^{−3 to} 1.3 × 10 ⁻² is more preferable.

  In the present invention, in particular, an electron-donating colorless dye precursor, which is one of the color forming components, is encapsulated in a microcapsule, and (A + 5) μm when the volume standard median diameter is Aμm. The number of the above microcapsules is preferably 5000 to 30000 per 2 cm × 2 cm. As a result, among the microcapsules encapsulating the electron-donating colorless dye precursor, a large size having a predetermined diameter or larger is selectively present, so that the density (for example, 0.02 or higher) that can be read by visual recognition or scanning. ΔD of) is suitably obtained.

  In addition, the volume standard median diameter of the microcapsules is such that the color density at a very low pressure (particularly less than 0.1 MPa (preferably surface pressure)) is increased, and visibility and readability during scanning are improved. 10 to 40 μm is preferable, 13 to 37 μm is more preferable, and 15 to 35 μm is more preferable.

  Among the above, the median diameter of the microcapsule volume standard is 15 to 35 μm from the viewpoint of increasing the color density at a pressure of less than 0.1 MPa (preferably surface pressure) and improving the visibility and the readability at the time of scanning. In some cases, it is particularly preferable that 7000 to 28000 microcapsules of (15 to 35 μm) +5 μm or more exist per 2 cm × 2 cm.

In the present invention, the median diameter of the volume standard is the sum of the volume of the particles on the large diameter side and the small diameter side when the entire microcapsule is divided into two with the particle diameter at which the cumulative volume is 50% as a threshold value. It is a diameter D ⁵⁰ that is a quantity. The median diameter of the volume standard is calculated by applying a microcapsule solution to a support, photographing the surface with an optical microscope at a magnification of 150 times, and measuring the size of all microcapsules in the range of 2 cm × 2 cm. Is the value to be

(Preparation of preparation solution for color former layer formation)
The microcapsules can be obtained as a dispersion liquid as described above. The microcapsule dispersion liquid is a preparation liquid (particularly a coating liquid) for forming a color former layer containing an electron donating colorless dye precursor as it is. It is good. Further, the microcapsule dispersion obtained as described above is further added with a starch or starch derivative fine powder, a buffer such as cellulose fiber powder, a water-soluble polymer binder such as polyvinyl alcohol, a vinyl acetate, an acrylic. System, hydrophobic polymer binders such as styrene / butadiene copolymer latex, fluorescent brighteners, antifoaming agents, penetrating agents, UV absorbers, preservatives, and other preparations (especially coating solutions) Good.
The prepared liquid (particularly the coating liquid) thus obtained is applied on a substrate by coating or the like, and dried to form a color former layer constituting the pressure measuring material. .

  When the preparation liquid for forming the color former layer is used as a coating liquid, the coating method of the coating liquid can be performed by applying and drying using a normal coating machine. Specific examples of the coating machine include an air knife coater, a rod coater, a bar coater, a curtain coater, a gravure coater, an extrusion coater, a die coater, a slide bead coater, and a blade coater.

  In the case where the pressure measurement material in the present invention is a two-sheet type constituted by coating the electron-donating colorless dye precursor-encapsulated microcapsules and the electron-accepting compound on separate substrates, for example, By applying the coating liquid on a desired sheet-like substrate directly or via another layer and drying, a sheet material on which at least a color former layer is formed can be obtained. In addition, in the case of a mono-sheet type configured by coating the electron-donating colorless dye precursor encapsulated microcapsules and the electron-accepting compound on a single sheet-like substrate, for example, on a desired substrate The above-mentioned coating solution is applied on the formed developer layer described later, and dried to obtain a pressure measurement material.

(Electron-accepting compound)
The developer layer constituting the pressure measuring material in the present invention preferably contains at least one electron accepting compound (developer).
Examples of the electron-accepting compound contained in the developer layer in the present invention include inorganic compounds and organic compounds. Specific examples of the inorganic compound include acidic clay, activated clay, attapulgite, zeolite, bentonite, and clay materials such as kaolin. Examples of the organic compound include metal salts of aromatic carboxylic acids, phenol formaldehyde resins, metal salts of carboxylated temperphenol resins, and the like. Among them, acid clay, activated clay, zeolite, kaolin, metal salt of aromatic carboxylic acid, metal salt of carboxylated temperphenol resin are preferable, and acid clay, activated clay, kaolin, metal salt of aromatic carboxylic acid More preferred.

  Preferable specific examples of the metal salt of the aromatic carboxylic acid include 3,5-di-t-butylsalicylic acid, 3,5-di-t-octylsalicylic acid, 3,5-di-t-nonylsalicylic acid, 3, 5-di-t-dodecylsalicylic acid, 3-methyl-5-t-dodecylsalicylic acid, 3-t-dodecylsalicylic acid, 5-t-dodecylsalicylic acid, 5-cyclohexylsalicylic acid, 3,5-bis (α, α-dimethyl) Benzyl) salicylic acid, 3-methyl-5- (α-methylbenzyl) salicylic acid, 3- (α, α-dimethylbenzyl) -5-methylsalicylic acid, 3- (α, α-dimethylbenzyl) -6-methylsalicylic acid, 3- (α-methylbenzyl) -5- (α, α-dimethylbenzyl) salicylic acid, 3- (α, α-dimethylbenzyl) -6-ethylsalicylic acid, 3-phenyl Zinc salts, nickel salts such as 5- (α, α-dimethylbenzyl) salicylic acid, carboxy-modified terpene phenol resin, salicylic acid resin which is a reaction product of 3,5-bis (α-methylbenzyl) salicylic acid and benzyl chloride , Aluminum salts, calcium salts and the like.

(Preparation of developer dispersion)
When the electron-accepting compound is the above-described inorganic compound, the developer dispersion can be prepared by mechanically dispersing the inorganic compound in an aqueous system, and the electron-accepting compound is an organic compound. In this case, the organic compound can be prepared by mechanically dispersing in an aqueous system or dissolving it in an organic solvent.
For details, the method described in JP-A-8-207435 can be referred to.

(Preparation of the developer for forming the developer layer)
The electron-accepting compound dispersion liquid prepared as described above may be used as a preparation liquid (particularly a coating liquid) for forming a developer layer containing an electron-accepting compound as it is. In addition, a preparation liquid (particularly a coating liquid) for forming a developer layer includes, as a binder, a styrene-butadiene copolymer latex, a vinyl acetate latex, an acrylate latex, polyvinyl alcohol, polyacrylic acid, Synthetic or natural polymer substances such as maleic anhydride-styrene-copolymer, starch, casein, gum arabic, gelatin, carboxymethylcellulose, methylcellulose and the like may be added. Further, as pigments, kaolin, calcined kaolin, kaolin aggregate, heavy calcium carbonate, light calcium carbonate in various forms (rice granular, square, spindle-shaped, rugged, spherical, aragonite columnar, amorphous, etc.), Talc, rutile type or anatase type titanium dioxide or the like may be added. Furthermore, if desired, an optical brightener, an antifoaming agent, a penetrating agent, and an antiseptic can be added.

  When the developer for forming the developer layer is used as a coating solution, the coating solution can be applied and dried using a normal coating machine. Specific examples of coating machines include blade coaters, rod coaters, air knife coaters, curtain coaters, gravure coaters, bar coaters, roll coaters, extrusion coaters, die coaters, slide bead coaters, blade coaters, etc. Can do.

  In the case where the pressure measurement material in the present invention is a two-sheet type constituted by coating electron-donating colorless dye precursor encapsulated microcapsules and electron-accepting compounds on separate substrates, for example, A coating material containing a colorant is applied directly or via another layer on a desired sheet-like substrate and dried to obtain a sheet material on which at least a developer layer is formed. In addition, in the case of a monosheet type in which a microcapsule encapsulating an electron-donating colorless dye precursor and an electron-accepting compound are coated on a single sheet-like substrate, for example, a desired sheet-like substrate The developer layer constituting the pressure measurement material can be formed by applying a developer-containing coating solution directly or via another layer and drying the coating solution.

The amount of the electron-accepting compound (developer) in the developer layer (in the case of coating, the coating amount) is preferably 0.1 to 30 g / m ² in terms of the mass after drying, more preferably the inorganic compound. case is 3 to 20 g / ^{m 2,} in the case of the organic compound is 0.1-5 g / ^{m 2,} more preferably, in the case of the inorganic compound is 5 to 15 g / ^{m 2,} in the case of organic compounds 0.2 to 3 g / m ² .

  The material for pressure measurement in the present invention has an inherent lower limit of the pressure measurement range depending on its configuration. The lower limit of the pressure measurement range is preferably 0.01 to 0.1 MPa, more preferably 0.02 to 0.05 MPa.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not limited to a following example.

[Example 1]
<Preparation of uneven sheet>
The uneven | corrugated sheet | seat (1) in which a base part and a convex part consist of a hard thermoplastic resin was produced by the method manufactured using a hot press system.
Here, hard acrylic was used as the hard thermoplastic resin.

The thickness of the base part of the obtained uneven sheet (1) was 0.1 mm, and the total thickness was 0.3 mm. Moreover, the shape of the convex part was a cylindrical shape.
In this convex part, the diameter of the lower surface (surface in contact with the base) and the upper surface (exposed surface parallel to the base) is 0.714 mm, and the height (distance from the base to the exposed surface) is 0.2 mm. Met.
Moreover, the convex part was arrange | positioned at the grid | lattice form of a 2 mm space | interval.
Moreover, when the Young's modulus after hardening of a convex part was measured with Tensilon (RTM-50 made from Orientec), it was 1000 MPa.

<Preparation of pressure measurement material>
-Preparation of electron-donating colorless dye precursor-encapsulated microcapsule solution (A)-
In 70 parts of diarylethane, 18 parts of the following compound (A) as an electron donating colorless dye precursor was dissolved to obtain a solution A. Next, 0.4 part of an ethylenediamine butylene oxide adduct dissolved in 1 part of methyl ethyl ketone was added to the stirring solution A to obtain a solution B. Further, 2 parts of a trimethylolpropane adduct of tolylene diisocyanate dissolved in 1 part of methyl ethyl ketone was added to the stirring solution B to obtain a solution C. And said solution C was added to the solution which melt | dissolved 6 parts of polyvinyl alcohol in 150 parts of water, and it emulsified and dispersed. 300 parts of water was added to the emulsified liquid after emulsification and dispersion, and the mixture was heated to 70 ° C. with stirring, cooled for 1 hour and then cooled. Water was added to adjust the concentration to obtain an electron-donating colorless dye precursor-encapsulated microcapsule liquid (A) having a solid concentration of 18%.

The number average wall thickness (δ) of the obtained microcapsules was 0.11 μm, and the median diameter D ⁵⁰ in the volume standard was 20 μm. The number average wall thickness is an average value obtained by averaging the capsule wall thicknesses of five microcapsules with a scanning electron microscope, and the median diameter is obtained by applying a microcapsule solution to a desired support and using an optical microscope. The image was taken at 150 times, and the size of all the microcapsules in the range of 2 cm × 2 cm was measured and calculated. δ / D was 0.006.

-Preparation of electron-donating colorless dye precursor-encapsulated microcapsule solution (B)-
The electron-donating colorless dye precursor-encapsulated microcapsule liquid (A) obtained above is subjected to cross-flow filtration multiple times using a filter with a pore size of 25 μm, and an electron-donating colorless dye precursor-encapsulated microcapsule of 25 μm or more. Removed. Water was added thereto to adjust the concentration to obtain an electron donating colorless dye precursor-encapsulated microcapsule liquid (B) having a solid concentration of 18%.

-Preparation of electron-donating colorless dye sheet-
50 parts of the electron donating colorless dye inclusion precursor microcapsule (A) obtained above and 50 parts of the electron donating colorless dye precursor inclusion microcapsule (B) are mixed, and the polyethylene terephthalate (PET) having a thickness of 75 μm is mixed. On the sheet, a color former layer was formed by coating and drying with a bar coater so that the mass after drying was 5.0 g / m ^2, and an electron donating colorless dye sheet was obtained.

-Preparation of developer-containing liquid-
To 100 parts of sulfuric acid-treated activated clay (electron-accepting compound), 5 parts of a 40% aqueous sodium hydroxide solution and 300 parts of water are added and dispersed with a homogenizer, and further, 50 parts of a 10% aqueous solution of sodium salt of casein, and 30 parts of styrene-butadiene latex was added to prepare a developer-containing liquid containing an electron accepting compound (developer).

The obtained developer-containing liquid was coated on a 75 μm thick polyethylene terephthalate sheet with a bar coater so that the solid coating amount was 10 g / m ² , and dried to form a developer layer. A developer sheet was obtained.
As described above, a two-sheet type pressure measuring material comprising an electron donating colorless dye sheet and a developer sheet was produced. The pressure measurement range of this pressure measurement material is 0.04 to 0.4 MPa.

<Pressure measurement>
Using the concavo-convex sheet and the pressure measurement material obtained above, the pinching pressure measurement on the transport roller in the printer manufacturing process was performed.
Specifically, first, an electron-donating colorless dye sheet and a developer sheet were overlapped so that the color former layer and the developer layer were in contact with each other to obtain a two-sheet type pressure measurement material. Next, the concavo-convex sheet and the pressure measuring material are overlapped so that the convex portion is on the developer sheet side to form a laminated body, and the laminated body is passed between two conveying rollers facing each other. I let you.
After the passage, a grid-like color development region was formed on the developer sheet.

  A grid-like color development area formed on the developer sheet is read by a reading system (pressure image analyzer shown in FIG. 10) having a scanner, a calculation section, and a display section, and the density of each color development area is set to a pressure value. Converted into

<Pressure measurement result>
The pressure measurement result for the color development region of 15000 points was an average value of 0.02 MPa, and the difference between the maximum value and the minimum value was 0.03 MPa.
As described above, the pressure and its distribution could be satisfactorily measured within the range of 0.04 MPa or less, which is the measurement lower limit of the pressure measurement material.

Here, the pressure measurement lower limit in the case of performing pressure measurement using both the uneven sheet (1) and the pressure measurement material was confirmed as follows.
First, five types of cuboid weights having a bottom surface of 2 cm × 2 cm and weights of 0.001 MPa, 0.002 MPa, 0.003 MPa, 0.004 MPa, and 0.005 MPa were prepared. Next, each weight was placed on a laminated body in which an uneven sheet and a pressure measurement material were overlapped, and each color development area was read by a reading system. As a result, the color density was too thin to be read at 0.001 MPa, 0.002 MPa, and 0.003 MPa, but could not be read at 0.004 MPa and 0.005 MPa.
From the above, the pressure measurement lower limit in the case of performing pressure measurement using both the uneven sheet (1) and the pressure measurement material was 0.004 MPa, and the pressure gain R was 10.
Therefore, in the above measurement,
S = (0.714 / 2) ² × π = 0.400,
(L × L) / R = (2.0 × 2.0) /10=0.40,
S = (L × L) / R
The relationship was established.

[Example 2]
<Pressure measurement>
Using the concavo-convex sheet obtained in Example 1 and the pressure measurement material, the bonding pressure measurement in the adhesion of the glass substrate in the liquid crystal display manufacturing process was performed.
First, the laminated body was comprised like Example 1. FIG. Next, two glass substrates used for manufacturing a liquid crystal display were prepared, the laminate was sandwiched between the two, and the process of the reduced pressure bonding process was performed. The above process was adjusted to −0.1 MPa by a decompression device.
After the decompression bonding process, a grid-like color development region was formed on the developer sheet.

  A grid-like color development area formed on the developer sheet is read by a reading system (pressure image analyzer shown in FIG. 10) having a scanner, a calculation section, and a display section, and the density of each color development area is set to a pressure value. Converted into

<Pressure measurement result>
The pressure measurement result for the color development region of 15000 points was an average value of 0.01 MPa, and the difference between the maximum value and the minimum value was 0.02 MPa.
As described above, the pressure and its distribution could be satisfactorily measured within the range of 0.04 MPa or less, which is the measurement lower limit of the pressure measurement material.

Example 3
<Pressure measurement>
Using the concavo-convex sheet obtained in Example 1 and the pressure measurement material, the pressing pressure measurement in the polishing of the silicon wafer in the semiconductor manufacturing process was performed.
First, the laminated body was comprised like Example 1. FIG. Next, the laminate was sandwiched between the stage of the silicon wafer polishing apparatus and the silicon wafer, and a pressing pressure of 0.005 MPa, which was a set pressure in the polishing process, was applied.
After the polishing process, a grid-like color development region was formed on the developer sheet.

  A grid-like color development area formed on the developer sheet is read by a reading system (pressure image analyzer shown in FIG. 10) having a scanner, a calculation section, and a display section, and the density of each color development area is set to a pressure value. Converted into

<Pressure measurement result>
The pressure measurement result for the color development region of 15000 points was an average value of 0.005 MPa, and the difference between the maximum value and the minimum value was 0.01 MPa.
As described above, the pressure and its distribution could be satisfactorily measured within the range of 0.04 MPa or less, which is the measurement lower limit of the pressure measurement material.

Example 4
<Preparation of uneven sheet (2)>
The uneven sheet (2) was produced using the uneven sheet manufacturing apparatus 60 shown in FIG.
First, the base material 42 was continuously supplied by the supply roller 22, and the monomer solution 36 was continuously applied on the supplied base material 42 by the coating device 34. Here, as the base material 42, a PET (polyethylene terephthalate, hereinafter the same) film having a width of 450 mm and a thickness of 100 μm was used. The supply speed and the conveyance speed were 2 m / min. As the monomer solution 36, a mixture of an acrylic monomer and a photopolymerization initiator was used (detailed composition is as follows). The coating amount of the monomer solution 36 was 60 ml / m ² and the coating width was 300 mm.

~ Monomer solution composition ~
・ Acrylic monomer ・ ・ ・ 66 parts by mass ・ Photopolymerization initiator ・ ・ ・ 1 part by mass ・ Methyl ethyl ketone ・ ・ ・ 33 parts by mass

  Next, the substrate 42 coated with the monomer solution 36 is brought into close contact with the arc of the pattern roll 50, and the pattern roll 50 is applied while the monomer solution 36 is filled between the recess 41 on the surface of the pattern roll 50 and the substrate 42. It was rotated at a speed of 2 m / min. As the pattern roll 50, a pattern roll having a diameter of 350 mm and a width (length in the rotation axis direction) of 500 mm was used.

Next, the base material 42 and the monomer solution 36 are irradiated with UV light (ultraviolet light, wavelength 365 nm) from the UV light source 31 to cure the monomer solution 36 to form a convex portion 44 made of an acrylic UV curable resin. did. The UV irradiation amount was 1000 mJ / cm ² .

  Next, when the base material 42 passed the conveyance roller 28, the formed convex portion 44 was peeled from the pattern roll 50. Furthermore, the base material 42 (uneven sheet (2)) on which the convex portions 44 were formed was wound up by the winding roller 32.

Thus, an uneven sheet (2) was obtained.
The thickness of the base part of the obtained uneven sheet (2) was 0.1 mm, and the total thickness was 0.3 mm. In addition, the shape of the convex portion was a shape in which a cone whose bottom surface was in contact with the base portion was cut by a plane parallel to the bottom surface.
In this convex part, the diameter of the lower surface (bottom surface in contact with the base) is 1.0 mm, the diameter of the upper surface (exposed surface parallel to the base) is 0.714 mm, and the height (from the base to the exposed surface) is The distance) was 0.2 mm.
Moreover, the convex part was arrange | positioned at the grid | lattice form of a 2 mm space | interval.
Moreover, when the Young's modulus after hardening of a convex part was measured with Tensilon (RTM-50 made from Orientec), it was 1000 MPa.

When the pressure measurement lower limit in the case of performing pressure measurement using both the uneven sheet (2) and the pressure measurement material was measured by the same method as in Example 1, it was 0.004 MPa, and the pressure gain R was 10 Met.
Therefore, in the above measurement,
S = (0.714 / 2) ² × π = 0.400,
(L × L) / R = (2.0 × 2.0) /10=0.40,
S = (L × L) / R
The relationship was established.

In Example 1, it replaced with the uneven | corrugated sheet | seat (1), and measured the pinching pressure in a conveyance roller similarly to Example 1 except using the uneven | corrugated sheet | seat (2) obtained above.
The pressure measurement result for 15000 points was an average value of 0.02 MPa, and the difference between the maximum value and the minimum value was 0.03 MPa.
As described above, the pressure and its distribution could be satisfactorily measured within the range of 0.04 MPa or less, which is the measurement lower limit of the pressure measurement material.

Example 5
Except for using the concavo-convex sheet (2) produced in Example 4, the adhesion pressure measurement in the adhesion of the glass substrate in the liquid crystal display production process was performed in the same manner as in Example 2.
The pressure measurement result for 15000 points was an average value of 0.01 MPa, and the difference between the maximum value and the minimum value was 0.02 MPa.
As described above, the pressure and its distribution could be satisfactorily measured within the range of 0.04 MPa or less, which is the measurement lower limit of the pressure measurement material.

Example 6
Except for using the concavo-convex sheet (2) produced in Example 4, the pressing pressure measurement in the polishing of the silicon wafer in the semiconductor manufacturing process was performed in the same manner as in Example 3.
The pressure measurement result for 15000 points was an average value of 0.005 MPa, and the difference between the maximum value and the minimum value was 0.01 MPa.
As described above, the pressure and its distribution could be satisfactorily measured within the range of 0.04 MPa or less, which is the measurement lower limit of the pressure measurement material.

[Comparative Example 1]
Except for using the following concavo-convex sheet, in the same manner as in Example 2, the bonding pressure measurement in the adhesion of the glass substrate in the liquid crystal display manufacturing process was performed.
The pressure measurement result for 15000 points was an average value of 0.01 MPa, and the difference between the maximum value and the minimum value was 0.003 MPa or less.
As described above, in the range of 0.04 MPa or less which is the measurement lower limit of the material for pressure measurement, the difference between the maximum value and the minimum value becomes too small, and the pressure distribution cannot be measured accurately. .

~ Uneven sheet of Comparative Example 1 ~
Base and convex material: SBR
Base thickness: 1mm
Convex height: 1mm
Convex apex angle: 100 °
Convex part interval: 2 mm

It is the perspective view which showed the uneven | corrugated sheet which concerns on 1st Embodiment. It is the perspective view which showed the uneven | corrugated sheet which concerns on 2nd Embodiment. It is the perspective view which showed the uneven | corrugated sheet which concerns on 3rd Embodiment. It is the perspective view which showed the uneven | corrugated sheet which concerns on 4th Embodiment. It is sectional drawing which showed typically the example of the uneven | corrugated sheet manufacturing apparatus used for the manufacturing method of the uneven | corrugated sheet of this invention. (A) is sectional drawing which showed notably the mode at the time of the low pressure in one Embodiment of this invention, (B) is a top view of the material for pressure measurements in (A). (A) is sectional drawing which showed notionally the mode at the time of the intermediate pressure in one Embodiment of this invention, (B) is a top view of the material for pressure measurements in (A). (A) is sectional drawing which showed notably the mode at the time of the high voltage | pressure in one Embodiment of this invention, (B) is a top view of the material for pressure measurements in (A). It is the top view which showed the example of the material for pressure measurements in one Embodiment of this invention. It is the figure which showed notionally the structure of the pressure image analyzer in one Embodiment of this invention. (A) It is the figure which showed the pressure measurement result in one Embodiment of this invention two-dimensionally, (B) is a pressure measurement result along the AA line of (A).

Explanation of symbols

10, 20, 30, 40, 70 Concavity and convexity sheet 12 Base part 14, 15, 16, 17, 44, 74 Convex part 60 Concavity and convexity sheet manufacturing apparatus 61 Object to be measured 62 Object to be measured 64 Material for pressure measurement 68 Color development region

Claims (4)

Electron acceptor as a color developing agent that reacts with the color former and has a color developer layer containing a microcapsule encapsulating an electron donating colorless dye precursor and a solvent as a color former on the substrate. The material A having a developer layer containing a functional compound on a substrate is overlaid so that the surface of the color former layer and the surface of the developer layer face each other, and the pressure measurement lower limit is 0.02 MPa to A concavo-convex sheet for performing pressure measurement in a pressure range below the pressure measurement lower limit using together with a material for pressure measurement at 0.05 MPa ,
On a base portion having a thickness of 0.05 mm or more made of a hard resin having a Young's modulus of 500 MPa or more, a height of 0.1 mm to 0.3 mm made of a hard resin having a Young's modulus of 500 MPa or more having an exposed surface parallel to the base portion . It has a plurality of protrusions and has a total thickness of 0.5 mm or less.
The pressure of the pressure measurement material with respect to the pressure measurement lower limit when the area of the exposed surface is S, the interval between the plurality of convex portions is L, and pressure measurement is performed using both the uneven sheet and the pressure measurement material. When the ratio of the lower limit of measurement is R,
S = (L × L) / R
An uneven sheet characterized by satisfying the above relationship.   The concavo-convex sheet according to claim 1, wherein a shape of the convex portion is a cylindrical shape.   The concavo-convex sheet according to claim 1, wherein the shape of the convex portion is a shape obtained by cutting a cone whose bottom surface is in contact with the base portion by a plane parallel to the bottom surface. (A) Between the uneven | corrugated sheet | seat of any one of Claims 1-3, the convex part of this uneven | corrugated sheet | seat is the said to-be-measured object and the said pressure measurement material in which a pressurization site | part develops color. A step of arranging in a direction to be the pressure measurement material side;
(B) pressing the exposed surface parallel to the base of the convex portion to the pressure measurement material by pressurization and forming a color development region having a density corresponding to the pressure by the convex portion on the pressure measurement material;
(C) reading the color development area with a scanner to obtain pressure;
Have
The pressure of the pressure measurement material with respect to the pressure measurement lower limit when the area of the exposed surface is S, the interval between the plurality of convex portions is L, and pressure measurement is performed using both the uneven sheet and the pressure measurement material. When the ratio of the lower limit of measurement is R,
S = (L × L) / R
The pressure measurement method characterized by satisfy | filling the relationship of these.

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