JP5020037B2 - Pressure distribution measurement method - Google Patents

Description

  The present invention relates to a pressure distribution measuring method using a pressure measuring material for measuring a pressure distribution such as a surface pressure.

  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.

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 materials conventionally used for measuring pressure and pressure distribution such as Patent Document 1 do not develop color in a very small pressure region below 0.1 MPa, such as around 0.05 MPa, or are sufficient. Color density cannot be obtained. For this reason, as described above, it cannot be used in a process where a slight pressure change affects product quality variation, or even if color is developed, it cannot be analyzed or controlled in detail when it is captured as data by scanning or the like. Etc. remained. Moreover, in the technique using the surface plate which has fine unevenness | corrugation on the surface of patent document 2, it uses for the use for which flexibility (flexibility) and thinness, such as pinching pressure measurement in a conveyance roller, are required, for example. I can't. Moreover, in the technique using the rubber elastic mat in which the convex portions of Patent Documents 3 and 4 are formed, the elastic mat itself serves as a cushion for relaxing the pressure distribution. It cannot be used for applications where thinness is required and accurate pressure distribution needs to be measured, such as suppression pressure measurement in a silicon wafer polishing process.

  The present invention has been made in view of the above, and an object thereof is to provide a pressure distribution measuring method capable of measuring a minute pressure or pressure distribution in vacuum pressure bonding.

<1> When the electron-donating colorless dye precursor encapsulated in the microcapsule and an electron-accepting compound that develops the color of the electron-donating colorless dye precursor, and the volume standard median diameter of the microcapsule is A μm In addition, there are 5000 to 30000 microcapsules having a diameter (A + 5) μm or more per 2 cm × 2 cm , and the pressure distribution in vacuum press bonding is measured using a pressure measuring material capable of measuring a pressure range of 0.1 MPa or less. A pressure distribution measurement method characterized by:
<2> before KOR microcapsules is ^{δ / D = 1.0 × 10 -3} ~2.0 × 10 -2 [[delta]: number average wall thickness of microcapsule (μm), D: the microcapsule volume standard The median diameter (μm)] relationship is satisfied, The pressure distribution measuring method according to <1> above.
<3> The pressure distribution measuring method according to <1> or <2>, wherein the pressure measurement material has a color density difference ΔD before and after pressing at 0.05 MPa is 0.02 or more. .

<4> prior Symbol pressure distribution measuring method according to any one of the above <1> to <3>, wherein the microcapsule volume standard median diameter A ([mu] m) is 10 to 40 [mu] m.

< 5 > The above-mentioned <1>, wherein a concavo-convex sheet satisfying the following condition (A) or (B) is further used, and the convex part of the concavo-convex sheet is arranged and measured so as to contact the pressure measuring material. The pressure distribution measuring method according to any one of> to < 4 >.
<Condition: (A)>
When there is a conical convex part made of soft resin on the base part with a thickness of 0.05 mm or more, the total thickness is 0.5 mm or less, and the color development area formed by pressing is read with a scanner to obtain the pressure The reading resolution of the scanner is I, the number of gradations read by the scanner is N, the height of the convex portion is H, the apex angle of the convex portion is θ, and the pressurization is the measurement lower limit of the material for pressure measurement When the diameter of the color-development region when performed under pressure is D _max ,
tan (θ / 2) = I × (N + 1) / (2 × H) and D _max ≧ I × (N + 1) is satisfied.
<Condition: (B)>
On the base portion having a thickness of 0.05 mm or more made of hard resin, there are a plurality of convex portions made of hard resin having an exposed surface parallel to the base portion, and the total thickness is 0.5 mm or less. When the area is S, the interval between the plurality of convex portions 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 the pressure measurement material is R,
The relationship of S = (L × L) / R is satisfied.

  ADVANTAGE OF THE INVENTION According to this invention, the pressure distribution measuring method which can measure the micro pressure in vacuum pressure bonding or its pressure distribution can be provided.

The pressure distribution measuring method of the present invention comprises an electron donating colorless dye precursor encapsulated in a microcapsule and an electron accepting compound for coloring the electron donating colorless dye precursor, and the volume standard median of the microcapsule When the diameter is A μm, there are 5000 to 30000 microcapsules having a diameter (A + 5) μm or more per 2 cm × 2 cm, and a pressure measurement material capable of measuring a pressure range of 0.1 MPa or less is used. It is characterized by measuring a pressure distribution in the pressure bonding.
The pressure distribution measuring method of the present invention can measure a minute pressure or pressure distribution in vacuum pressure bonding by adopting the above configuration.

The pressure measurement method of the present invention is not particularly limited as long as it is a method for measuring the pressure distribution in vacuum pressure bonding using the pressure measurement material, but (1) a pressure measurement method using only a pressure measurement material, and (2 ) When the following condition (A) or (B) is satisfied, a pressure distribution measurement method in which a concavo-convex sheet is further used and the convex part of the concavo-convex sheet is arranged and measured so as to contact the pressure measuring material is a preferred embodiment. .
<Condition: (A)>
When there is a conical convex part made of soft resin on the base part with a thickness of 0.05 mm or more, the total thickness is 0.5 mm or less, and the color development area formed by pressing is read with a scanner to obtain the pressure The reading resolution of the scanner is I, the number of gradations read by the scanner is N, the height of the convex portion is H, the apex angle of the convex portion is θ, and the pressurization is the measurement lower limit of the material for pressure measurement When the diameter of the color-development region when performed under pressure is D _max ,
tan (θ / 2) = I × (N + 1) / (2 × H) and the relationship of D _max ≧ I × (N + 1) is satisfied.
<Condition: (B)>
On the base portion having a thickness of 0.05 mm or more made of hard resin, there are a plurality of convex portions made of hard resin having an exposed surface parallel to the base portion, and the total thickness is 0.5 mm or less. When the area is S, the interval between the plurality of convex portions 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 the pressure measurement material is R,
The relationship of S = (L × L) / R is satisfied.

Among the pressure measuring methods (1) and (2), the method (2) is preferable because it can measure a pressure range of a fine pressure. Among the methods (2), the pressure measurement methods satisfying conditions A and B satisfy the conditions (2A) and (2B) pressure measurement methods (hereinafter simply referred to as the method (2A) as appropriate). , Also referred to as (2B) method).
Hereinafter, each measurement method of (1), (2A) and (2B) will be described in detail.

<(1) Pressure measurement method using only pressure measurement material>
In this invention, although the example of embodiment of the measuring method using only the material for pressure measurement is demonstrated, it is not limited to the following embodiment.
The pressure measurement material in the present embodiment includes an electron donating colorless dye precursor encapsulated in a microcapsule and an electron accepting compound (developer) for coloring the electron donating colorless dye precursor, and the microcapsule And a mono-sheet type in which the electron-accepting compound is provided on a single substrate and a two-sheet type (an electron-donating colorless dye sheet and a developer sheet) provided on separate substrates. The pressure measurement material is preferably the two-sheet type from the viewpoint of storage stability and handling. The pressure measurement material will be described later in detail.

The pressure measurement method of this embodiment is preferably composed of steps (a) to (c).
(A) Process: The process of arrange | positioning a to-be-measured object and the material for pressure measurement in the vacuum chamber of a vacuum press-bonding apparatus.
(B) Step: A step of reducing pressure until the pressure in the vacuum chamber reaches a desired pressure.
(C) Step: releasing the vacuum in the vacuum chamber, taking out the pressure measurement material, reading the color density of the color development region formed in the pressure measurement material, and measuring the pressure distribution based on the color density .

The pressure measurement method of this embodiment will be specifically described below with reference to FIG. 1, but is not limited thereto.
FIG. 1 is a perspective view showing an embodiment of a pressure measuring method in vacuum bonding according to the present invention.
The pressure distribution in the present invention can be measured by performing the following steps (a) to (c).

<(A) Process>
In the step (a), the object to be measured (glass substrates 104 and 106) is placed in the vacuum chamber 110 of the vacuum pressure bonding apparatus 100, and the pressure measurement material 102 (102A and 102C) is further formed on the entire surface of the object 104 to be measured. ).

The vacuum pressure bonding apparatus is not particularly limited, and a known vacuum pressure bonding apparatus, a vacuum chamber, or the like can be used.
The objects to be measured 104 and 106 are not particularly limited, and a liquid crystal panel, a glass substrate, a silicon wafer, a printed board, a transfer roller of a copying machine or a printer, or the like can be used. When the measurement object is a liquid crystal panel, a UV curable resin 112 is provided between the measurement objects 104 and 106.
In this embodiment, among the pressure measurement materials described later, a two-sheet type pressure measurement material comprising an electron donating colorless dye sheet and a developer sheet is used, but the present invention is not limited to this.
Furthermore, the material for pressure measurement may be one sheet type or two sheet types used alone, or may be used in combination of a plurality of one sheet type and / or two sheet types as required. Not.
Regarding the positional relationship between the object to be measured and the pressure measuring material in the vacuum chamber, the pressure measuring material may be located on the entire lower surface of the object to be measured or between the glass substrates 104 and 106 of the object to be measured. It may also be selected as necessary.
Although the size of the pressure measurement material is smaller than the size of the object to be measured, it can be measured using a plurality of pressure measurement materials. From the viewpoint of measurement of surface pressure distribution and accuracy of surface pressure measurement, the pressure distribution It is preferable that the size is the same as the size of the object to be measured.

<(B) Process>
In this step, the pressure in the vacuum chamber 110 is reduced by a vacuum pump (not shown) through the pressure reducing port V of the vacuum chamber 110 until the pressure in the vacuum chamber 110 reaches a desired pressure.

  In the step (b), the object to be measured (glass substrates 104 and 106) and the pressure measurement material 102 in the vacuum chamber 110 that has been decompressed are made by the air vent embossed sheets (180 μm PET) 108 provided above and below them. The pressure measurement material that has been pressure-bonded and pressed is colored according to a desired pressure (degree of vacuum).

The desired pressure is a pressure of 0.1 MPa or less, preferably 0.0 to 0.09 MPa, more preferably 0.0 to 0.08 MPa, from the viewpoint of obtaining a sufficient pressure-bonding effect, and 0.0 to 0.08 MPa. 0.70 MPa is particularly preferable. The use of a pressure measurement material capable of measuring a pressure of 0.1 MPa or less is preferable in that a device or the like that has conventionally been difficult to measure can be measured.
The apparatus used for the pressure reduction is a vacuum pump, but is not particularly limited as long as the pressure can be reduced, and a known pressure reduction apparatus can be used.
In the present embodiment, the object to be measured is pressure-bonded using an air vent embossed sheet, but there is no particular limitation as long as it has a function of allowing air to be released and pressure-bonding the object to be measured.
Examples of the material of the air vent embossed sheet include polyethylene terephthalate, polyethylene, polystyrene, polypropylene, polycarbonate, and acrylic from the viewpoint that it is preferable to have hardness without cushioning properties.

<(C) Process>
The vacuum in the vacuum chamber 110 is released, the pressure measurement material 102 decompressed in the step (b) is taken out, the superposed electron-donating colorless dye sheet 102A and the developer sheet 102C are peeled off, and the pressure The color density (D) of the color development area formed on the developer sheet 102C is read in accordance with the degree of color, and the in-plane pressure distribution is measured based on the color density.

The color density distribution formed on the developer sheet is analyzed by reading the density distribution with a pressure image analysis system using a scanner (for example, FPD-9210, manufactured by FUJIFILM Corporation). By doing so, the pressure distribution can be measured.
Moreover, it can measure simply by observing the color density visually.

<(2A) Pressure Measurement Method Using Pressure Measurement Material and Convex Sheet (Convex is Conical)>
The pressure measurement method of the present embodiment (hereinafter, also simply referred to as (2A) pressure measurement method) is (a) a total of having a conical convex portion made of a soft resin on a base portion having a thickness of 0.05 mm or more. A step of disposing a concavo-convex sheet having a thickness of 0.5 mm or less between the object to be measured and a pressure measurement material that develops a pressure at a position where the convex portion is on the pressure measurement material side; ) Pressing the convex portion of the concavo-convex sheet against the pressure measurement material by pressurization, deforming the convex portion, and forming a color development region having an area corresponding to the deformation amount of the convex portion on the pressure measurement material; And (c) reading the color development area with a scanner to obtain pressure, wherein the reading resolution of the scanner is I, the reading gradation by the scanner is N, the height of the convex portion is H, and the convexity The apex angle of the part is θ, the pressurization is the pressure measurement material When the diameter of the color regions when performing a constant lower pressure to a D _max,
tan (θ / 2) = I × (N + 1) / (2 × H), and
D _max ≧ I × (N + 1)
It is configured to satisfy the relationship.

  When measuring the pressure applied to the object to be measured using the pressure measurement material that develops color at the pressurization site, the concavo-convex sheet is placed on the side where the convex part becomes the pressure measurement material and the pressure measurement material By being sandwiched between the object to be measured, the pressure applied to the entire object to be measured can be concentrated on the convex part of the uneven sheet. For this reason, even when the pressure applied to the whole object to be measured is equal to or lower than the measurement lower limit specific to the material for pressure measurement, pressure measurement and pressure distribution measurement can be performed. However, depending on the properties of the concavo-convex sheet (for example, the thickness of the base, the height of the bulge, the shape of the bulge, the hardness of the bulge (the amount of deformation), etc.), the pressure is relaxed by the concavo-convex sheet itself. May cause inconveniences that may occur and the number of steps for classifying the pressure value at each measurement point may be insufficient, and so on.

When the pressure measuring method is the configuration of the present embodiment, that is, when a concavo-convex sheet satisfying the above relationship is used, the pressure applied between the object to be measured and the pressure measuring material by pressure is the pressure. When it is the measurement lower limit of the measurement material, the convex portion of the concavo-convex sheet is crushed until the height becomes almost zero, and the diameter (area) of the coloring region becomes maximum. On the other hand, when the pressure is less than the measurement lower limit of the material for pressure measurement, the convex portion will be crushed to a height, and the diameter (area) of the coloring region at this time is the measurement lower limit. This is smaller than the diameter (area) of the coloring region.
Therefore, by reading the diameter (area) of the color development area with a scanner, the pressure applied between the object to be measured and the pressure measurement material by pressurization is less than the measurement lower limit specific to the pressure measurement material. However, the pressure value or 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 “measurement lower limit of the pressure measurement material” refers to the measurement lower limit when the pressure measurement material alone is used for pressure measurement without being used together with the uneven sheet. Although the pressure measurement material has a specific measurement lower limit depending on its configuration, the pressure measurement sensitivity can be improved by using it in combination with the concavo-convex sheet (that is, the measurement lower limit specific to the pressure measurement material). Pressure below the value can be measured).

In the present invention, the reading resolution I of the scanner is the minimum width that the scanner can read. In the present invention, the diameter of the color development region is actually a continuous value according to the pressure at the time of pressurization, but as a stepwise (discontinuous) value for each resolution I at the time of reading by the scanner. Read.
The reading gradation N by the scanner in this embodiment indicates a stage when reading the diameter of the color development region, and can be set in advance.
In this embodiment, when the read value of the diameter of the color development region is I, the gradation is “0” (0 gradation), and when the read value is 2I, the gradation is “1” (1 gradation). When the reading value is 3I, the gradation is “2” (2 gradations), and when the reading value is I × (N + 1), the gradation is “N” (N gradations).

In the pressure measurement method of this embodiment, between the I and the N, and the diameter D _{max of the} color development region when the pressurization is performed at a pressure that is a measurement lower limit of the pressure measurement material,
D _max ≧ I × (N + 1)
There is a relationship.
When D _max is smaller than “I × (N + 1)”, the number of steps when classifying the pressure value at each measurement point is insufficient, and the minute pressure below the measurement lower limit of the pressure measurement material or its distribution Can not be measured.
From the viewpoint of obtaining the effect of the present invention more effectively,
D _max = I × (N + 1)
It is preferable to satisfy the relationship.

The pressure measurement method of this embodiment is particularly suitable for pressure measurement when the pressure applied between the object to be measured and the pressure measurement material is in the range of P _{min to} P _max below.
P _min : Pressure at which the reading value of the diameter of the coloring area is I P _max : Pressure at which the reading value of the diameter of the coloring area is I × (N + 1) Here, P _max is equal to or lower than the measurement lower limit specific to the material for pressure measurement Pressure.
In the present embodiment, the diameter of the color development region at the pressure P _min may be referred to as D _min . The D _min is equal to the I.

The specific range of the reading resolution I of the scanner is preferably 0.2 mm or less and more preferably 0.15 mm or less from the viewpoint of more effectively achieving the effects of the present invention.
The specific range of the reading gradation N of the scanner is preferably 10 or more and more preferably 15 or more from the viewpoint of more effectively achieving the effects of the present invention.
It is preferable that the pressure range which can be measured in the pressure measurement method of this embodiment is a range below the measurement lower limit 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.

<(A) Process>
In the step (a) in the present invention, a concavo-convex sheet having a total thickness of 0.5 mm or less having a conical convex portion made of a soft resin on a base portion having a thickness of 0.05 mm or more is used. It is a process of arrange | positioning in the direction from which the said convex part turns into the said pressure measurement material side between the pressure measurement materials which color.
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.
FIG. 2 is a perspective view showing the concavo-convex sheet 10 in one embodiment of the present invention. A conical convex portion 14 is provided on the sheet-like base portion 12. In FIG. 2, for convenience of explanation, the number of convex portions is nine, but in the present invention, the number of convex portions, the density, and the like are not limited (preferred density will be described later).

<(B) Process>
In the step (b) in the present invention, the convex portion of the concavo-convex sheet is pressed against the pressure measuring material by pressurization, the convex portion is deformed, and the color of the area corresponding to the deformation amount of the convex portion is formed on the pressure measuring material. This is a step of forming a region.

Here, referring to FIGS. 3A, 3B, 4A, 4B, 5A, and 5B, an embodiment of pressurization is described. explain.
3 (A), 4 (A), and 5 (A) are diagrams conceptually showing the state of pressurization in one embodiment of the present invention. 3A, FIG. 4A, and FIG. 5A, the pressure measurement material 24 is disposed between the DUT 20 and the DUT 22, and the DUT 22 and the pressure are further measured. Between the measurement material 24, the concavo-convex sheet 10 is arranged in such a direction that the convex portion 14 is on the pressure measurement material 24 side. Due to the pressure applied between the object to be measured 20 and the object to be measured 22 (in FIG. 3 to FIG. 5, the pressure P is applied from both sides by the pressure P), the convex part of the concave-convex sheet is deformed, and the deformation amount of the convex part A color development region 28 having a corresponding area is formed in the pressure measurement material 24. The pressure measurement material 24 in the above embodiment is a two-sheet type, which will be described later, an electron donating colorless dye sheet 24A provided with a coloring layer on a base material, and a color developing layer provided on the base material. The developer sheet 24 </ b> C thus formed is superposed so that the color-developing layer and the developer layer are in contact with each other.

3A is a cross-sectional view conceptually showing a state at a low pressure, and FIG. 3B is a plan view conceptually showing the pressure measurement material in FIG. As shown in FIGS. 3A and 3B, the amount of deformation of the convex portion is small, and the area of the color development region 28 is also small.
4A is a cross-sectional view conceptually showing a state at medium pressure, and FIG. 4B is a plan view conceptually showing the pressure measurement material in FIG. 4A. . As shown in FIGS. 4A and 4B, the deformation amount of the convex portion and the area of the coloring region 28 are larger than those at the time of low pressure.
5A is a cross-sectional view conceptually showing a state at high pressure, and FIG. 5B is a plan view conceptually showing the pressure measurement material in FIG. 5A. As shown in FIGS. 5A and 5B, the deformation amount of the convex portion and the area of the color development region 28 are larger than those at the intermediate pressure.

  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 20 and the measurement object 22 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 the resolution I and the gradation N using 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, a method of converting the read area of the color development region into a pressure value based on the relationship between the area of the color development region obtained in advance and the pressure is used. Can do. 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. 6-8, this invention is not limited to this form. In this embodiment, the area 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. 6 is a plan view showing an example of the pressure measurement material after the step (b), FIG. 7 is a diagram conceptually showing the configuration of the pressure image analyzer, and FIG. FIG. 8 is a diagram two-dimensionally showing the pressure measurement result, and FIG. 8B is the pressure measurement result along the line AA in FIG. 8A.

In FIG. 6, a plurality of color development regions 28 having various diameters corresponding to the deformation amount of the convex portion are formed on the pressure measurement material 24 that is a pressure measurement material. In FIG. 6, reference numeral 28 is given only to a part of the coloring regions.
In the pressure image analysis apparatus 50 shown in FIG. 7, a scanner 30 for reading a color development area, a microcomputer 32 for calculating pressure and pressure distribution from the read color development area, and the obtained pressure and pressure distribution are displayed in a multidimensional manner. And multi-dimensional display means 44.

The image of the color development region 28 (pressing point) of the pressure measurement material 24 shown in FIG. 6 is read by the scanner 30 shown in FIG.
The output of the scanner 30 is input to the microcomputer 32. The computer 32 has various functions configured by software. The pressurization point reading means 34 takes the output of the scanner 30 and obtains the coordinate position and area of each color development region 28. The pressure detector 36 calculates a pressure P ₀ corresponding to this area. That is, a conversion table, map, or conversion formula for calculating the conversion of the pressure P ₀ corresponding to each area is stored in advance in the lookup table (LUT) 38, and the pressure detection means 36 uses this LUT 38 to store the pressure P _0. Is calculated.

The equal pressure distribution calculating means 40 obtains the pressure distribution by connecting the positions where the pressures using the pressure P ₀ of the color development region 28 become equal. That is, when the color development region 28 is positioned on a lattice with a constant interval as shown in FIG. 8A, the distribution is shown with the pressure P ₀ of the color development region 28 on the AA line as the vertical axis. It becomes like 8 (B).

In FIG. 8B, 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 40, 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 40 obtains coordinates R _a , R _b , and R _c that become predetermined constant pressures (set pressures) P _a , P _b , and P _c . Repeating the calculation of the above A-A line and another line B-B, with respect to grid lines, such as line C-C, by connecting the coordinate R _a becomes set pressure P _a, FIG. 8 (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 set pressures P _a , P _b , and P _c can be arbitrarily changed by the setting changing means 42. 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 44. For example, the isobaric lines S _a , S _b , and S _c shown in FIG. 8A 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 28 of the pressure measuring material 24 appearing in a lattice shape can be changed to a pressure distribution continuously displayed in two dimensions or multi dimensions. Therefore, the pressure distribution can be immediately known visually, and handling becomes extremely simple.

<(2B) Pressure measurement method using a pressure measurement material and a concavo-convex sheet having a convex portion having an exposed surface parallel to the base portion>
The concavo-convex sheet in this embodiment has a plurality of convex portions made of a hard resin having 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, and has a total thickness of 0.5 mm. The following uneven sheet (hereinafter also referred to as “uneven sheet B” as appropriate). Details will be described later.
Here, although the example of embodiment of the pressure measuring method using the uneven | corrugated sheet | seat B is demonstrated, it is not limited to the following embodiment.
The pressure measurement method in this embodiment is:
(A) a step of arranging the concavo-convex sheet between the object to be measured and the pressure measurement material in which the pressurization site develops a color so that the convex portion of the concavo-convex sheet is on 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 and obtaining pressure,
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 concave-convex sheet of the present embodiment is placed between the object to be measured and the pressure measurement material that develops the pressure, and the convex portion of the concave-convex sheet faces the pressure measurement material. It is a process of arranging.
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, referring to FIGS. 17A, 17B, 17A, 18B, 19A, and 19B, an embodiment of pressurization is described. explain.
FIG. 17A, FIG. 18A, and FIG. 19A are diagrams conceptually showing the state of pressurization in one embodiment of the present invention. In FIG. 17A, FIG. 18A, and FIG. 19A, a pressure measurement material 64 is disposed between the object to be measured 61 and the object to be measured 62, and further, the object to be measured 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 (pressurized by pressure P from both sides in FIGS. 17 to 19) concentrates on the convex portion of the concave-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.

FIG. 17A is a cross-sectional view conceptually showing a state at a low pressure, and FIG. 17B is a plan view conceptually showing the pressure measurement material in FIG. As shown in FIGS. 17A and 17B, the pressure applied to the convex portion 74 is low, and the color density of the coloring region 68 is low.
18A is a cross-sectional view conceptually showing a state at medium pressure, and FIG. 18B is a plan view conceptually showing the pressure measurement material in FIG. 18A. . As shown in FIGS. 18A and 18B, the pressure applied to the convex portions 74 is higher than that at the time of low pressure, and the color density of the coloring region 68 is high.
FIG. 19A is a cross-sectional view conceptually showing a state at high pressure, and FIG. 19B is a plan view conceptually showing the pressure measurement material in FIG. 19A. As shown in FIGS. 19A and 19B, 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. 20-22, 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. 20 is a plan view showing an example of the pressure measurement material after the step (b), FIG. 21 is a diagram conceptually showing the configuration of the pressure image analyzer, and FIG. FIG. 22 is a diagram two-dimensionally showing the pressure measurement result, and FIG. 22B is the pressure measurement result along the line AA in FIG. 22A.

In FIG. 20, 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. 20, some color development regions are shown). Only 68 is attached).
In the pressure image analyzing apparatus 100 shown in FIG. 21, 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.

An image of the color development region 68 (pressing point) of the pressure measurement material 64 shown in FIG. 20 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 at regular intervals as shown in FIG. 22A, the distribution is shown with the pressure P ₀ of the color development region 68 on the AA line as the vertical axis. 22 (B). In FIG. 22 (A), a pressing point having a large color density in the color development region and a high pressing pressure is represented by a plot having a large radius, and a pressing point having a low color density and a low pressing pressure is represented by a plot having a small radius. Yes.

In FIG. 22 (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 . Repeating the calculation of the above A-A line and another line B-B, with respect to grid lines, such as line C-C, by connecting the coordinate R _a becomes set pressure P _a, FIG. 22 (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. 22A 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]
The pressure measurement material used in the present invention will be described in detail below.
The material for measuring pressure in the present invention is not particularly limited as long as it is a material capable of measuring a pressure range of 0.1 MPa or less, and among them, an electron-donating colorless dye precursor (hereinafter referred to as “color former”). A microcapsule encapsulating (preferably further containing a solvent) and an electron-accepting compound (hereinafter also referred to as “developer”) that reacts with the electron-donating colorless dye precursor to cause color development. It is preferable that the microcapsules are provided on a single base material or on separate base materials. In particular, the microcapsule has δ / D = 1.0 × 10 ^{−3 to} 2.0 × 10 ⁻² [δ : Number average wall thickness (μm) of macrocapsules, D: median diameter (μm) of volume standard of microcapsules] is preferably satisfied.
The pressure measuring material can measure in a pressure range of 0.1 MPa or less by adopting the above configuration.

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 pressurization of 0.1 MPa or less. You can choose.
Among these, from the viewpoint of obtaining good color developability at a low pressure of 0.05 MPa or less, 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 is good at a low pressure of less than 0.1 MPa. This is particularly preferable in terms of obtaining color development. By forming the microcapsule satisfying this relational expression, it is possible to form a coloring system that easily develops color even under pressure in a low pressure region (pressure region 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 contents do not leak, and the low pressure region (preferably a pressure of less than 0.1 MPa). 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.

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

  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 alone in a site where pressure or pressure distribution is to be measured. Or put and pressurize.

  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. Material A (developer sheet) having a developer layer containing developer and Material B (color developer sheet) having a microcapsule-containing color developer layer on a substrate such as a sheet or film. Both materials are configured so that the surface where the microcapsules of material B are present (color developer layer surface) and the surface where the electron accepting compound of material A is present (surface of the developer layer) face each other. , And in a stacked state, press between the parts where pressure or pressure distribution is to be measured, or place and pressurize.

  Pressurization can be performed by applying pressure (point pressure, linear pressure, surface pressure, etc.) by a point, a line, or a surface by any method. In the present invention, particularly in a low pressure range of less than 0.1 MPa, the density difference for identifying a minute pressure difference is small, and this is effective when a surface pressure that makes it difficult to grasp the differential pressure is applied.

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 pressure measurement material according to the present invention uses a color development reaction between an electron donating colorless dye precursor and an electron accepting compound from the viewpoint of obtaining a readable concentration difference, and before and after pressurization at 0.05 MPa. It is preferable that the color density difference ΔD is configured to be 0.02 or more.

In the present invention, it is preferable that a density difference ΔD (≧ 0.02) that can be read by visual recognition or scanning is expressed by applying a slight pressure of 0.05 MPa.
By adopting such a configuration, it is possible to detect and measure minute pressure differences and pressure distributions that increase with the enhancement of functionality and definition of products in recent years.

  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 microstandard of (A + 5) μm or more when the median diameter of the volume standard of the microcapsule is Aμm. By setting the number of capsules to 5,000 to 30,000 per 2 cm × 2 cm, the microcapsules encapsulating the electron-donating colorless dye precursor are selectively made to be larger than a predetermined diameter. A ΔD of 0.02 or more, which is a density that can be read by visual recognition or scanning, is preferably obtained.

  If the median diameter of the microcapsule volume standard is A μm, if the number of microcapsules of (A + 5) μm or more is 5000 or more per 2 cm × 2 cm, the microcapsules encapsulating the electron-donating colorless dye precursor will develop color. The number of relatively large size capsules that are affected increases, resulting in higher color density and better readability. On the other hand, when the number is 30000 or less, capsule destruction (that is, color development) is likely to occur at a slight pressure of 0.05 MPa.

  As described above, the microcapsules of (A + 5) μm or more increase the color density when a fine pressure of 0.05 MPa is applied, and improve visibility and reading at the time of scanning, 5000 per 2 cm × 2 cm. The case where -30000 pieces exist is preferable, and the case where 7000-28000 pieces exist is still more preferable.

  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, in the present invention, the median diameter of the volume standard of the microcapsule is used in order to increase the color density at a pressure of less than 0.1 MPa (preferably the surface pressure) and improve the visibility and the readability at the time of scanning. Is 15 to 35 μm, it is particularly preferred that there are 7000 to 28000 microcapsules of (15 to 35 μm) +5 μm or more 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

(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)
The microcapsule contained in the color former layer of the pressure measuring material in the present invention contains at least one kind of electron-donating colorless dye precursor.
As the electron-donating colorless dye precursor 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, Furthermore, 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 a low pressure (less than 0.1 MPa ( From the viewpoint of increasing color developability (preferably surface pressure) and obtaining a high concentration at low pressure (increasing concentration change (concentration gradient) with respect to pressure change), a range of 10 to 100% by mass is preferable, and 20 to 100% by mass is preferable. The range is more preferable, and the range of 30 to 100% by 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 the electron-donating colorless dye precursor is dissolved in a 95% aqueous acetic acid solution. Specifically, in a 95% acetic acid aqueous solution of an electron donating colorless dye precursor whose concentration was adjusted so that the absorbance was 1.0 or less, the measurement cell length was Acm, and the electron donating colorless dye precursor was When the concentration is B mol / L and 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 microcapsule in the present invention includes 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.

  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.

  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, melamine / 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 for the capsule wall material 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 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 electron donating colorless dye precursor, the solvent, and the 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.

(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 of the material for pressure measurement in the present invention 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 developer dispersion liquid (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.

<Uneven sheet>
The uneven sheet used in the present invention is the uneven sheet used in the pressure measurement methods (2A) and (2B) (hereinafter also referred to as “uneven sheet A” and “uneven sheet B” as appropriate). Hereinafter, the uneven sheets A and B will be described in detail.

<Uneven sheet A>
The concavo-convex sheet A used in the (2A) pressure measuring method has a conical convex portion made of a soft resin on a base portion having a thickness of 0.05 mm or more, and is configured to have a total thickness of 0.5 mm or less. The 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 to 0.4 mm, and more preferably 0.07 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 to 0.15 mm, more preferably 0.05 to 0.1 mm.

There is no particular limitation on the material of the base portion, and materials such as hard resin and soft resin (for example, soft resin of the same material as the convex portion) can be used.
Among these, a hard resin is preferable from the viewpoint of ease of production and ease of handling, and from the viewpoint of more accurately measuring pressure or its distribution.
In the present invention, the “hard resin” refers to a resin having a Young's modulus of 500 MPa or more.
As the hard resin, polyethylene terephthalate (PET), polyethylene, polystyrene, polypropylene, polycarbonate, acrylic and the like are preferable, polyethylene terephthalate (PET), polycarbonate and acrylic are more preferable, and polyethylene terephthalate (PET) is particularly preferable.

The convex part in the said uneven | corrugated sheet A consists of soft resin, and has a conical structure.
In the present invention, “soft resin” refers to a resin having a Young's modulus of 50 MPa or less.
As the soft resin, soft UV curable resin and soft acrylic are preferable, and soft UV curable resin is more preferable.
The soft UV curable resin is preferably an acrylic UV curable resin.
In the present invention, “UV” means ultraviolet light (Ultra Violet).

Although the convex part in the said uneven | corrugated sheet A will not be specifically limited if it is the hardness which deform | transforms with a pressure, It is preferable that the Young's modulus of a convex part is 0.05-5 MPa, and it is 0.1-1 MPa. More preferred.
The apex angle of the convex portion in the concavo-convex sheet A is preferably 145 to 165 °, more preferably 150 to 160 °, from the viewpoint of more effectively achieving the effects of the present invention.
As a space | interval of the convex part in the said uneven | corrugated sheet A, 1-10 mm is preferable from a viewpoint which show | plays the effect by this invention more effectively, and 2-5 mm is more preferable.
The height of the convex portion in the uneven sheet A is preferably 0.05 to 0.45 mm, more preferably 0.1 to 0.3 mm, from the viewpoint of more effectively achieving the effects of the present invention.
As the density of the convex portion of the concavo-convex sheet A, from the standpoint of demonstrating the effect of the invention more effectively, preferably 1 to 100 / mm ^2, more preferably 4 to 25 pieces / mm ^2.

FIG. 9 is a cross-sectional view schematically showing the concavo-convex sheet 52 in one embodiment of the present invention ((2A) measurement method). The concavo-convex sheet in FIG. 9 has a form in which the base portion and the convex portion are made of the same material soft thermoplastic resin. Convex portions having a height H and an apex angle θ are provided at intervals L on the base portion having a thickness t1.
FIG. 10 is a cross-sectional view schematically showing an uneven sheet 54 according to another embodiment of the present invention. The concavo-convex sheet of FIG. 10 has a form in which the convex portion is a soft UV curable resin and the base material (base portion) is a hard resin. Convex portions having a height H and an apex angle θ are provided at intervals L on a base material (base portion) having a thickness t2.

<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, which is a precursor of a UV curable resin, is supplied between a pattern roll having a reverse pattern (concave portion) formed on the surface of a concavo-convex sheet and a continuously supplied substrate. Irradiating the supplied monomer solution with UV light to form a convex portion made of a UV curable resin on the substrate, and peeling the formed convex portion from the pattern roll to form a substrate on which the convex portion is formed. A method of winding up the substrate as needed is preferable.

FIG. 11 is a cross-sectional view schematically showing an uneven sheet manufacturing apparatus 60 used in the preferred manufacturing method.
The concavo-convex sheet manufacturing apparatus 60 continuously supplies the base material 82 from the upstream side to the downstream side of the transport path that continuously transports the base material 82 that is the base of the concavo-convex sheet (direction of the transport direction S). And a take-up roller 72 for taking up the base material 82. The feed roller 62 for carrying the base material 82 is provided. Further, a coating device 74 is provided at a position facing the transport roller 64 through the transport path of the base material 82 so that the monomer solution 76 that is a precursor of the UV curable resin can be applied onto the base material 82. It has become. Between the transport roller 66 and the transport roller 68, a cylindrical pattern roll 80 is provided. During this period, the base material 82 is deformed along the arc of the pattern roll 80, and the pattern roll is rotated. It is designed to move together. The surface of the pattern roll 80 is provided with a concave portion 81 (in FIG. 10, only a portion of the concave portions is provided with a reference numeral 81 for convenience) that is a reverse pattern of the convex portion of the concavo-convex sheet to be manufactured. Further, a UV light source 70 for curing the monomer solution 76 supplied on the base material 82 is provided at a position facing the pattern roll 80 via the transport path of the base material 82.

Next, a method for producing an uneven sheet using the uneven sheet manufacturing apparatus 60 will be described.
First, the base material 82 is continuously supplied by the supply roller 62, and the monomer solution 76 is continuously applied on the supplied base material 82 by the coating device 74.
As for the width | variety (length in the direction orthogonal to the conveyance direction S) of the base material 82, 200-2000 mm is preferable. The length of the base material 82 is preferably 100 to 4000 m. As for the thickness of the base material 82, 50-450 micrometers is preferable. The conveyance speed is preferably 0.5 to 50 m / min. The coating width of the monomer solution 76 is preferably 100 to 1800 mm, and the coating amount of the monomer solution 76 is preferably ² to 200 ml / m ² .

The base material 82 on which the monomer solution 76 is applied is deformed along the arc of the pattern roll 80 that rotates in the rotation direction R after passing through the transport roller 66, and is transported in accordance with the rotation. At this time, the monomer solution 76 is filled between the recess 81 on the surface of the pattern roll 80 and the substrate 82.
Here, the rotation speed of the pattern roll 80 is preferably equal to the conveyance speed of the base material 82. The diameter of the pattern roll 80 is preferably 100 to 500 mm, and the width of the pattern roll 80 is preferably 300 to 2200 mm.

Next, UV light (ultraviolet light) is irradiated from the UV light source 70 to the base material 82 and the monomer solution 76 that move in accordance with the rotation of the pattern roll 80, and the monomer solution 76 is cured to be made of a UV curable resin. A convex portion 84 is formed on the base material 82. In this case, the UV irradiation amount is preferably 100 to 2000 mJ / cm ² .

Next, when the base material 82 passes the transport roller 68, the formed convex portion 84 is peeled off from the pattern roll 80. The base material 82 on which the convex portions 84 are formed is taken up by the take-up roller 72.
The wound base material 82 with the convex portion 84 is cut into an appropriate size according to the application and used as an uneven sheet.

<Uneven sheet B>
The concavo-convex sheet B used in the (2B) pressure measurement method is a concavo-convex sheet for performing pressure measurement together with the pressure measurement material, 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 a hard resin having an exposed surface parallel to the base portion, having a total thickness of 0.5 mm or less, an area of the exposed surface being S, and an interval between the plurality of convex portions being L 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 using both the uneven sheet and the pressure measurement material is R, S = (L × L) / R
It is the uneven | corrugated sheet | seat comprised so that the relationship may be satisfy | filled.

  When the uneven sheet B has the above-described configuration, when pressure is applied between the object to be measured and the material for pressure measurement at a pressure measurement lower limit specific to the material for pressure measurement, 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 on which 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. In particular, it is suitable for pinching pressure measurement in a conveyance roller in a copier or printer manufacturing process, bonding pressure measurement in glass substrate adhesion in a liquid crystal display manufacturing process, and pressing pressure measurement in polishing a silicon wafer in a semiconductor manufacturing process. .

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 the pressure measurement material alone is used for pressure measurement without being used together with the uneven sheet B. The pressure measurement material has a specific measurement lower limit depending on its configuration, but when used in combination with the concavo-convex sheet B of this embodiment, the pressure measurement sensitivity becomes R times (ie, the pressure measurement material specific 1 / R of the measurement lower limit value can be measured). 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 pressure measurement is performed using both the uneven sheet B 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 uneven sheet B in this embodiment is preferably a range that is equal to or lower than the measurement lower limit value 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 concavo-convex sheet B in this embodiment has a plurality of convex portions made of hard resin having an exposed surface parallel to the base portion on a base portion having a thickness of 0.05 mm or more made of hard resin, and has a total thickness of 0. It is configured to be 5 mm or less. 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 B 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. 13).
FIG. 12 is a perspective view showing the uneven sheet B10 according to the first embodiment. A cylindrical convex portion 14 is provided on the sheet-like base portion 12.
FIG. 13 is a perspective view showing a concavo-convex sheet B20 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. 14 is a perspective view showing an uneven sheet B30 according to the third embodiment. A quadrangular prism-shaped convex portion 16 is provided on the sheet-like base portion 12.
FIG. 15 is a perspective view showing an uneven sheet B40 according to the fourth embodiment. A triangular prism-shaped convex portion 17 is provided on the sheet-like base portion 12.

The base part in this embodiment consists of hard resin.
In this embodiment, “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, etc., more preferably polyethylene terephthalate (PET), polycarbonate, acrylic, and particularly preferably polyethylene terephthalate (PET). .

The convex part in this embodiment 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).

From the viewpoint of more effectively achieving the effects of the present invention, it is preferable that the convex portion in the present embodiment has a hardness that does not deform due to pressure.
The Young's modulus of the convex portion is preferably 500 MPa or more, and more preferably 1000 MPa or more.
As the exposed surface parallel to the base portion of the projecting portion in the present embodiment, from the viewpoint of the effect of the invention with greater effectiveness ^is preferably ^{0.05mm 2 ~20mm 2, 0.1mm 2 ~5mm} 2 Gayori preferable.
The distance between the convex portions in the present embodiment 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 this embodiment 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 this embodiment is preferably 1 piece / mm ^{2 to} 100 pieces / mm ² from the viewpoint of more effectively achieving the effect of the present invention, and 4 pieces / mm ^{2 to} 25 pieces / mm ^2. Is more preferable.

<Method for producing uneven sheet B>
The manufacturing method of the concavo-convex sheet B in this embodiment is not particularly limited, a method of manufacturing using a photolithography method, a method of manufacturing using a hot press method, a method of manufacturing using a pattern roll and a UV curable resin. 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 B is thin and can be formed uniformly. For example, a monomer solution that is a precursor of a UV curable resin is supplied between a pattern roll on which the reverse pattern (concave portion) of the convex portion of the concave-convex sheet B is formed and a substrate that is continuously supplied. Irradiate the supplied monomer solution with UV light to form a convex portion made of UV curable resin on the base material, and peel the formed convex portion from the pattern roll to obtain a base material on which the convex portion is formed. Further, if necessary, a method of winding the substrate is suitable.

FIG. 16 is a cross-sectional view schematically showing the concavo-convex sheet B manufacturing apparatus 60 used in the preferable manufacturing method.
The concavo-convex sheet B 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 serving as a base, and the supplied base. The conveyance roller 24 which conveys the material 42 continuously, the conveyance roller 26, the conveyance roller 28, and the winding roller 32 for winding up the base material 42 are comprised. 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 recess 41 (in FIG. 5, only a part of the recesses are provided with a reference numeral 41 for convenience) that is a reverse pattern of the protrusions of the uneven sheet B 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 manufacturing the concavo-convex sheet B using the concavo-convex 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 the uneven sheet B.
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 B 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.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not limited to a following example. Unless otherwise specified, “part” is based on mass.

[Example 1]
(Preparation of electron-donating colorless dye sheet (1))
-Preparation of electron-donating colorless dye precursor-encapsulated microcapsule solution (A)-
As an electron donating colorless dye, 18 parts by mass of the compound (A) was dissolved in 70 parts by mass of isopropyl biphenyl to obtain a solution A. 0.4 parts by mass of an ethylenediamine butylene oxide adduct dissolved in 1 part by mass of methyl ethyl ketone was added to the stirring solution A to obtain a solution B. A solution C was obtained by adding 2 parts by mass of a trimethylolpropane adduct of tolylene diisocyanate dissolved in 1 part by mass of methyl ethyl ketone to the solution B being stirred. Solution C was added to a solution obtained by dissolving 6 parts by mass of polyvinyl alcohol in 150 parts by mass of water, and emulsified and dispersed. 300 parts by weight of water was added to the emulsion, heated to 70 ° C. while stirring, stirred for 1 hour, and then cooled to obtain a coating liquid containing microcapsules encapsulating an electron-donating colorless dye. The median diameter of the obtained microcapsules based on the volume standard was 20 μm.

-Preparation of electron-donating colorless dye sheet (1)-
This microcapsule coating solution was applied and dried on a 75 μm-thick polyethylene terephthalate (PET) sheet so that the mass after drying was 3.0 g / m ^2, and the electron-donating colorless dye sheet (1) Got.

(Preparation of developer sheet (1))
-Preparation of developer containing coating solution-
To 100 parts by weight of sulfuric acid-treated activated clay, 5 parts by weight of 40% aqueous sodium hydroxide and 300 parts by weight of water are added and dispersed with a homogenizer. Further, 50 parts by weight of 10% aqueous sodium salt of casein, 30 parts by weight of styrene-butadiene latex Was added to prepare a developer (electron-accepting compound) -containing coating solution.
-Production of developer sheet (1)-
On a 75 μm thick polyethylene terephthalate (PET) sheet, a developer-containing coating solution was applied so that the solid content coating amount was 10 g / m ² to obtain a developer sheet (1).

(Preparation of pressure measurement material (1))
The electron donating colorless dye sheet (1) and the developer sheet (1) obtained above are obtained by combining the surface of the color former layer of the electron donating colorless dye sheet and the surface of the developer layer of the developer sheet. The materials for pressure measurement (1) were produced by superimposing them facing each other.

(Preparation of uneven sheet (1))
Using the concavo-convex sheet A manufacturing apparatus 60 shown in FIG. 11, a concavo-convex sheet (1) having a base portion made of a hard resin and a convex portion made of a soft resin as shown in FIG. 10 was produced.
First, the base material 82 was continuously supplied by the supply roller 62, and the monomer solution 76 was continuously applied on the supplied base material 82 by the coating device 74. Here, as the substrate 82, 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 76, an acrylic monomer and a photopolymerization initiator diluted with methyl ethyl ketone to 67 mass% were used (detailed composition is as follows). The coating amount of the monomer solution 76 was 90 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 base material 82 coated with the monomer solution 76 is brought into close contact with the arc of the pattern roll 80, and the pattern roll 80 is applied while filling the monomer solution 76 between the concave portion 81 on the surface of the pattern roll 80 and the base material 82. It was rotated at a speed of 2 m / min. As the pattern roll 80, 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 82 and the monomer solution 76 are irradiated with UV light (ultraviolet light, wavelength 365 nm) from the UV light source 70 to cure the monomer solution 76 to form a convex portion 84 made of an acrylic UV curable resin. did. The UV irradiation amount was 1000 mJ / cm ² .

  Next, when the base material 82 passed the conveyance roller 68, the formed convex portion 84 was peeled from the pattern roll 80. Furthermore, the base material 82 (concave / convex sheet (1)) on which the convex portions 84 were formed was wound up by the winding roller 72.

Thus, an uneven sheet (1) was obtained.
The thickness of the base part of the obtained uneven sheet (1) was 0.1 mm, and the total thickness was 0.3 mm. Further, the shape of the convex portion was a conical shape having an apex angle of 151.93 ° and a height of 0.2 mm. The convex portions were arranged in a lattice shape with an interval of 2 mm. The Young's modulus after the convex portion was cured was measured by Tensilon (RTM-50 manufactured by Orientec Co., Ltd.) and found to be 1 MPa.

(Evaluation / Measurement)
The material for pressure measurement obtained above is sandwiched between the air vent embossing sheet 107 of the apparatus for bonding two glass substrates by the vacuum pressure shown in FIG. The pressure was sucked with a vacuum pump until the pressure became 0.02 MPa, and then the vacuum was released, the pressure measuring material was taken out, and the two superimposed sheets were peeled to examine the color development state.
Although there was a trace of the air vent embossed sheet, it was confirmed that it was uniformly colored and pressed in a well-balanced manner.

[Example 2]
In Example 1, the UV curable resin in FIG. 1 was removed, and the pressure measurement material (1) produced in the same manner as in Example 1 was sandwiched between the two glass substrates (104 and 106). Suction was performed with a vacuum pump until the pressure reached 0.02 MPa.
In the same manner as in Example 1, the color development state of the pressure measurement material was examined.
Although it was confirmed that the pressure measurement material was uniformly colored, it was confirmed that the pressure was uniformly applied, but uneven coloring due to air leakage was partially observed.

[Example 3]
In Example 2, the pressure measurement material (1) and the concavo-convex sheet (1) are sandwiched between the two glass substrates (104 and 106), and the pressure in the chamber is 0.02 MPa as in Example 2. Suction was performed with a vacuum pump until
In the same manner as in Example 2, the color development state of the pressure measurement material was examined.
It was found that the pressure balance was poor because the pressure measuring material was darkly colored on one side. The position accuracy of the glass substrate was reviewed.
The color development was clearer than in Example 2, and air escaped from the gaps between the concavo-convex sheet (1).
After adjusting the positional accuracy of the glass plate, the same operation as described above was performed, and the color development state of the pressure measurement material was examined.
It was confirmed that the position measurement of the glass plate was well adjusted because the pressure measuring material was uniformly colored and pressed in a balanced manner.

[Comparative Example 1]
In Example 1, instead of using the pressure measurement material obtained in Example 1, the same applies except that the pressure measurement material produced by the method of Example 1 described in JP-B-57-24852 is used. Then, the state of color development was examined.
The pressure measuring material was hardly colored and the pressure distribution could not be examined.

[Comparative Example 2]
In Example 1, instead of using the pressure measurement material obtained in Example 1, the color development state was examined in the same manner except that NITTA Corporation Tactile Sensor BIG-MAT1300 was used. Since the vacuum system is a closed system, it could not be connected to the analysis system during suction with a vacuum pump.
The BIG-MAT 1300 was taken out and connected to the analysis system, but no information could be read.

It is sectional drawing which showed notionally the mode at the time of the low voltage | pressure in one Embodiment of this invention. It is the perspective view which showed the uneven | corrugated sheet in one Embodiment of this invention. (A) is sectional drawing which showed notionally 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 notably 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). It is sectional drawing which showed typically the uneven | corrugated sheet in one Embodiment of this invention. It is sectional drawing which showed typically the uneven | corrugated sheet in another embodiment of this invention. It is sectional drawing which showed typically the uneven | corrugated sheet manufacturing apparatus used for the preferable manufacturing method of an uneven | corrugated sheet in one Embodiment of this invention. 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 notionally 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 notably 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, 52, 54, 70 Uneven sheet A or B
12 Base part 14, 15, 16, 17, 44, 74, 84 Convex part 20, 22, 61, 62 Object to be measured 24, 64 Pressure measuring material 28, 68 Color development area 30 Scanner 60 Concavity and convexity sheet A or B manufacturing apparatus DESCRIPTION OF SYMBOLS 100 Vacuum pressure bonding apparatus 102 Pressure measuring material 104,106 Measured object 107,108 Air release embossed sheet 110 Vacuum chamber 112 UV curable resin V Depressurization port

Claims (5)

When the electron-donating colorless dye precursor encapsulated in the microcapsule and an electron-accepting compound that develops the color of the electron-donating colorless dye precursor, the diameter when the median diameter of the microcapsule volume standard is A μm (A + 5) There are 5000 to 30000 microcapsules of 2 μm × 2 cm or more, and the pressure distribution in vacuum pressure bonding is measured using a pressure measurement material capable of measuring a pressure range of 0.1 MPa or less. A characteristic pressure distribution measuring method. Before KOR microcapsules is ^{δ / D = 1.0 × 10 -3} ~2.0 × 10 -2 [[delta]: Macro number average wall thickness of the capsule ([mu] m), D: the volume standard microcapsules median diameter ( The pressure distribution measuring method according to claim 1, wherein the relationship of μm)] is satisfied.   The pressure distribution measuring method according to claim 1 or 2, wherein the pressure measuring material has a color density difference ΔD before and after pressurizing at 0.05 MPa of 0.02 or more. 4. The pressure distribution measuring method according to claim 1, wherein the volume standard median diameter A (μm) of the microcapsule is 10 to 40 μm. 5. The concavo-convex sheet satisfying the following condition (A) or (B) is further used, and the convex part of the concavo-convex sheet is arranged and measured so as to be in contact with the pressure measuring material. 5. The pressure distribution measuring method according to any one of 4 above.
<Condition: (A)>
When there is a conical convex part made of soft resin on the base part with a thickness of 0.05 mm or more, the total thickness is 0.5 mm or less, and the color development area formed by pressing is read with a scanner to obtain the pressure The reading resolution of the scanner is I, the number of gradations read by the scanner is N, the height of the convex portion is H, the apex angle of the convex portion is θ, and the pressurization is the measurement lower limit of the material for pressure measurement When the diameter of the color-development region when performed under pressure is D _max ,
tan (θ / 2) = I × (N + 1) / (2 × H) and D _max ≧ I × (N + 1) is satisfied.
<Condition: (B)>
On the base portion having a thickness of 0.05 mm or more made of hard resin, there are a plurality of convex portions made of hard resin having an exposed surface parallel to the base portion, and the total thickness is 0.5 mm or less. When the area is S, the interval between the plurality of convex portions 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 the pressure measurement material is R,
The relationship of S = (L × L) / R is satisfied.

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