WO2019003838A1 - Pressure measurement material - Google Patents

Abstract

The invention relates to a pressure measuring material comprising: a microcapsule A having an electron donor dye precursor therein; and a microcapsule B having no electron donor dye precursor therein, and having a solvent having a melting point or pour point less than or equal to 30 ° C and a polar organic compound having a melting above 30 ° C within it.

Description

Material for pressure measurement

The present disclosure relates to a pressure measurement material.

Materials for measuring pressure (that is, materials used for measuring pressure) are used in applications such as a bonding process of liquid crystal glass, solder printing on a printed circuit board, pressure control between rollers, and the like. As an example of the material used for pressure measurement, there is, for example, a pressure measurement film represented by Prescale (trade name; registered trademark) provided by Fuji Film Co., Ltd., for example.

In recent years, materials for pressure measurement for measuring minute pressure have been studied.
For example, in JP 2009-19949 A, a pressure measurement material having a color density difference ΔD of 0.02 or more before and after pressurization at 0.05 MPa in order to obtain a visible or readable density with a minute pressure Has been proposed.

Further, in JP 2009-63512 A, as a two-sheet type pressure measurement material capable of obtaining good color development at low pressure, the number average wall thickness σ in the microcapsules and the surface roughness Ra of the developer layer are used. Attention is focused on the material for pressure measurement in which color development against rubbing is suppressed.

As described in JP-A-2009-19949 and JP-A-2009-63512 described above, materials for pressure measurement for measuring minute pressure have been studied.
However, in recent years, due to the progress in product sophistication and high definition, there is an increasing need to more precisely grasp the area to which a minute pressure is applied.
For example, in the field of liquid crystal panels, a vacuum bonding method may be adopted as a bonding method in response to an increase in area, and in this case, a pressure less than 0.1 MPa (that is, atmospheric pressure) It is necessary to grasp the added area precisely.
Moreover, in the field of smartphones, in order to improve the yield at the time of bonding, along with the thinning of modules, bonding at a minute pressure of 0.05 MPa or less is required. For this reason, in the field of smartphones, it is necessary to accurately grasp the area to which a minute pressure of 0.05 MPa or less is applied.

Under the above-mentioned conditions, the measurable pressure range of the pressure measurement film marketed, that is, the pressure range in which color development can be obtained by pressurization is in the range of 0.05 MPa or more. For this reason, when a weak pressure below 0.05 MPa is applied to the commercially available pressure measurement film, the color difference required for detection is insufficient, or the pressure difference is obtained even if color is obtained. It is difficult to obtain the density gradation necessary for the judgment.

In the prior art, for example, as in the pressure measurement material described in JP-A-2009-19949, a material is proposed in which the color density difference ΔD is improved before and after pressurization at 0.05 MPa. However, if it is attempted to increase the sensitivity so that visible or readable concentration and density gradation can be obtained even by application of a minute pressure below 0.05 MPa, coloration due to rubbing or the like during handling is likely to occur. To be
Therefore, even under a pressure range of 0.05 MPa or less, color development is satisfactorily achieved, color development corresponding to a minute pressure difference (that is, density gradation) is obtained, and unnecessary color development can be suppressed by rubbing or the like. Establishment of technology is desired.

An object of one embodiment of the present invention is to provide a pressure measurement material which is excellent in gradation of color development under a minute pressure of 0.05 MPa or less and in which color development due to rubbing is suppressed.

The following modes are included in the specific means for solving said subject.
<1> A microcapsule A which contains an electron donating dye precursor,
A microcapsule B which contains a solvent having a melting point or a pour point of 30 ° C. or less and a polar organic compound having a melting point of more than 30 ° C. and does not contain an electron donating dye precursor,
Materials for pressure measurement including.
<2> The pressure measurement material according to <1>, wherein the polar organic compound having a melting point of more than 30 ° C. is a compound having an alkyl group having 12 or more carbon atoms and an amide bond.
The polar organic compound whose melting | fusing point is 30 degreeC or more is at least 1 sort (s) selected from the group which consists of a salicylic acid type compound, the salt of a salicylic acid type compound, a phenol type compound, and a sulfonamide type compound as described in <1>. Material for pressure measurement.
The material for pressure measurement according to any one of <1> to <3>, wherein the median diameter D50B of the volume standard of the <4> microcapsule B is larger than the median diameter D50A of the volume standard of the microcapsule A.
<5> A first material in which a color former layer containing microcapsules A is disposed on a first substrate, and a developer layer containing an electron accepting compound are disposed on a second substrate The second material,
Equipped with
The material for pressure measurement according to any one of <1> to <4>, wherein at least one of the first material and the second material contains a microcapsule B.
<6> On the color former layer of the first material, the color developer layer of the second material having the same area as the color former layer of the first material is brought into contact with the color former layer of the first material, The material for pressure measurement according to <5>, wherein the difference in color density after subtraction of the first material after repeated movements of the first material 20 times is less than 0.02 before the abrasion is less than 0.02.
<7> The concentration difference obtained by reducing the concentration after applying a pressure at 0.04 MPa from the concentration after applying a pressure at 0.05 MPa and applying a pressure at 0.04 MPa is 0.20 or more <1> The material for pressure measurement as described in any one of <6>.

According to one embodiment of the present invention, there is provided a pressure measurement material which is excellent in gradation of color development under a minute pressure of 0.05 MPa or less and in which color development due to rubbing is suppressed.

Hereinafter, the pressure measurement material of the present disclosure will be described in detail.
In the present disclosure, a numerical range represented using “to” means a range including numerical values described before and after “to” as the lower limit value and the upper limit value.
The upper limit value or the lower limit value described in a certain numerical value range may be replaced with the upper limit value or the lower limit value of the other stepwise description numerical value range in the numerical value range described stepwise in the present disclosure. In addition, in the numerical range described in the present disclosure, the upper limit value or the lower limit value described in a certain numerical range may be replaced with the value shown in the example.
In the present disclosure, the amount of each component in the composition means the total amount of the plurality of substances present in the composition unless a plurality of substances corresponding to each component are present in the composition. Do.
In the present disclosure, a combination of two or more preferred embodiments is a more preferred embodiment.

<Material for pressure measurement>
The material for pressure measurement of the present disclosure comprises a microcapsule A containing an electron donating dye precursor, a solvent having a melting point or a pour point of 30 ° C. or less (hereinafter abbreviated as “specific solvent” as appropriate) and a melting point or a fluid. A microcapsule B which contains a polar organic compound having a point of more than 30 ° C. (hereinafter, appropriately abbreviated as “specific polar organic compound”) and does not contain an electron donating dye precursor.

The electron donating dye precursor contained in the microcapsule A develops a color by contacting with the electron accepting compound which is a developer for causing the electron donating dye precursor to develop color.
As the specific polar organic compound contained in the microcapsule B, measurement performance such as sensitivity and color development can be improved in measurement of pressure or pressure distribution using color development reaction between electron donating dye precursor and color developer. Compounds can be selected.

As materials used for measurement of pressure, conventionally proposed and widely used, all such materials are suitable for detection of pressure in the range of 0.05 MPa or more applied when pressurized Used for On the other hand, in recent years, with high functionalization and high definition of products, the required pressure detection capability has become a range below 0.05 MPa. Although materials for pressure measurement described in JP-A-2009-19949 and JP-A-2009-63512 are conventionally provided, the pressure range suitable for detection deviates from the pressure range required in recent years. There is a possibility that

On the other hand, it is difficult to design a material for pressure measurement so that good color development can be obtained with a minute pressure, and concentration gradation appears in response to a wide pressure range. For example, when the sensitivity is increased to detect with a minute pressure, color development occurs with too little pressure as a result of which the pressure range in which density gradation appears is likely to narrow and moreover color develops due to slight rubbing during handling. It is easy to mix the color which is not planned to.

In view of the above, in the material for pressure measurement of the present disclosure, microcapsules A containing an electron donating dye precursor, a solvent having a melting point or a pour point of 30 ° C. or less (specific solvent) and a polar organic compound having a melting point of more than 30 ° C. A compound (specific polar organic compound) is contained, and microcapsules B not containing an electron donating dye precursor are mixed.

Thereby, the material for pressure measurement of the present disclosure can achieve color formation balance to a minute pressure, and even if the pressure is as low as 0.05 MPa or less, the material has excellent gradation of color development and coloration due to rubbing. It is possible to provide a suppressed pressure measurement material.
Here, the "toning property of color development" means the property that the color density increases with the increase of the applied pressure. A particularly preferable color development gradation is a property in which the color development density linearly increases (that is, the pressure and the color development density are proportional) as the pressure increases in a pressure range of 0.06 MPa or less.

Specifically, when pressure is applied to the pressure measurement material of the present disclosure, the microcapsule A is broken, whereby the electron donating dye precursor is in contact with the electron accepting compound (i.e., the developer), A colored area is formed. When the applied pressure is not uniform in the application area, the color is developed to a concentration corresponding to the pressure, and a color development area having gradation of density is formed.

The mixture of the microcapsules A and the microcapsules B in the material for pressure measurement of the present disclosure suppresses the breakage of the microcapsules A by the destruction of the microcapsules B when an unexpected minute pressure is applied. Unnecessary color development can be suppressed. That is, the microcapsule B has a function of suppressing the destruction of the microcapsule A (i.e., a function as a dummy capsule) by the destruction of the microcapsule B itself.

The specific solvent contained in the microcapsule B can improve the reactivity between the electron donating dye precursor and the developer when the microcapsule A is broken. Further, as the specific polar organic compound encapsulated by the microcapsule B, improvement of measurement performance such as sensitivity and color developability in measurement of pressure or pressure distribution using color development reaction of electron donor dye precursor and developer The compound which can contribute to can be selected. Therefore, the inclusion of the microcapsules B further improves the measurement performance of the material for pressure measurement.

Thereby, the material for pressure measurement of the present disclosure is excellent in color development at minute pressure while suppressing unnecessary color formation at minute pressure due to rubbing and the like, and concentration gradation corresponding to a wide pressure range. It is thought that it can be reproduced.

[Microcapsule A]
Microcapsule A is a microcapsule encapsulating an electron donating dye precursor which is a color forming component. The microcapsules A preferably contain a solvent, and may further contain other components such as an auxiliary solvent, an additive and the like, if necessary.

-Electron donating dye precursor-
The electron donating dye precursor is not particularly limited as long as it has a property of giving a electron or accepting a proton (hydrogen ion; H ⁺ ) such as an acid to develop a color, and it is colorless. Is preferred.
In particular, the electron donating dye precursor has a partial skeleton such as lactone, lactam, sultone, spiropyran, ester, amide, etc., and when contacted with an electron accepting compound described later, these partial skeletons open or Preference is given to colorless compounds which cleave.

As the electron donating dye precursor, those known in pressure-sensitive copying paper or thermosensitive recording paper applications can be used. For example, triphenylmethanephthalide compounds, fluoran compounds, phenothiazine compounds, indolylphthalide compounds, leucoauramine compounds, rhodamine lactam compounds, triphenylmethane compounds, diphenylmethane compounds, triazene compounds, Examples include various compounds such as spiropyran compounds and fluorene compounds.
For details of the above compounds, the description in JP-A-5-257272 can be referred to.
The electron donating dye precursors may be used singly or in combination of two or more.

From the viewpoint of enhancing the color forming property in a minute pressure range of 0.05 MPa or less and developing a high concentration at a minute pressure, that is, concentration change (concentration gradient) corresponding to a wide pressure range, Those having a high molar extinction coefficient (ε) are preferred. The molar absorption coefficient (ε) of the electron donating dye precursor is preferably 10000 mol ⁻¹ · cm ⁻¹ · L or more, more preferably 15000 mol ⁻¹ · cm ⁻¹ · L or more, and further more preferably Is preferably 25000 mol ^-1 · cm ^-1 · L or more.

As a preferable example of the electron donor dye precursor in which ε is in the above range, 3- (4-diethylamino-2-ethoxyphenyl) -3- (1-ethyl-2-methylindol-3-yl) -4 is mentioned. -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-methyl ester Luran (ε = 22000), 6-diethylamino-3-methyl-2- (2,6-xylidino) -fluoran (ε = 19000), 2- (2-chloroanilino) -6-dibutylaminofluoran (ε = 21000) And 3, 3-bis (4-dimethylaminophenyl) -6-dimethylaminophthalide (ε = 16000), 2-anilino-6-diethylamino-3-methylfluoran (ε = 16000), and the like.

When using alone an electron donating dye precursor having a molar absorption coefficient ε in the above range, or mixing two or more types including an electron donating dye precursor having a molar absorption coefficient ε in the above range The ratio of the electron donative dye precursor having a molar absorption coefficient (ε) of 10000 mol ⁻¹ · cm ⁻¹ · L or more in the total amount of the electron donating dye precursor is less than 0.05 MPa The range of 10% by mass to 100% by mass is preferable, and the range of 20% by mass to 100% by mass is more preferable from the viewpoint of enhancing color development in a minute pressure range and expressing concentration change (concentration gradient) with respect to a wide pressure range. Preferably, the range of 30% by mass to 100% by mass is more preferable.
When two or more types of electron donating dye precursors are used, it is preferable to use two or more types in which ε has a ^{value of} 10000 mol ⁻¹ · cm ⁻¹ · L or more, respectively.

The molar absorption coefficient (ε) can be calculated from the absorbance when the electron donating dye precursor is dissolved in an aqueous 95% acetic acid solution. Specifically, in a 95% acetic acid aqueous solution of an electron donative dye precursor whose concentration is adjusted so as to have an absorbance of 1.0 or less, the length of the measuring cell is A cm, and the concentration of the electron donative dye is B mol When / L and absorbance are C, they can be calculated by the following equation.
Molar extinction coefficient (ε) = C / (A × B)

-solvent-
The microcapsule A preferably contains at least one solvent.
As the solvent, known solvents in pressure-sensitive copying paper or thermosensitive recording paper applications can be used.
Specific examples of the solvent include alkyl naphthalene compounds such as diisopropyl naphthalene, diaryl alkane compounds such as 1-phenyl-1-xylyl ethane, alkyl biphenyl compounds such as isopropyl biphenyl, triaryl methane compounds, alkyl benzene compounds Aromatic hydrocarbons such as compounds, benzyl naphthalene compounds, diaryl alkylene compounds, aryl indane compounds; aliphatic hydrocarbons such as isoparaffin; soybean oil, corn oil, cottonseed oil, rapeseed oil, olive oil, coconut oil, castor oil, fish oil, etc. Natural animal and vegetable oils; natural high-boiling fractions such as mineral oils; and the like.

You may use a solvent individually by 1 type or in mixture of 2 or more types.
The mass ratio of the solvent to the electron donating dye precursor (solvent: precursor) contained in the microcapsule A is preferably in the range of 98: 2 to 30: 70 in terms of color developability, 97: 3 The range of ̃40: 60 is more preferable, and the range of 95: 5 to 50:50 is more preferable.

-Co-solvent-
The microcapsules A may contain an auxiliary solvent, if necessary.
As an auxiliary solvent, the solvent whose boiling point is 130 degrees C or less is mentioned.
More specifically, examples of the auxiliary solvent include ketone compounds such as methyl ethyl ketone, ester compounds such as ethyl acetate, and alcohol compounds such as isopropyl alcohol.

-Other ingredients-
The microcapsules A may contain other components other than the above, as necessary.
Other components may include additives such as ultraviolet light absorbers, light stabilizers, antioxidants, waxes, and odor control agents.

-Volume based median diameter of microcapsule A (D50A)-
The volume-based median diameter (hereinafter also referred to as “D50A”) of the microcapsule A is not particularly limited, but is preferably more than 10 μm and less than 40 μm.
When D50A is less than 40 μm, the coloring property does not become too high, so that coloring due to rubbing or the like can be further suppressed.
When D50A is more than 10 μm, unevenness on the surface of the layer containing microcapsules A (for example, application unevenness in a mode of applying and forming a color former layer containing microcapsules A) can be further suppressed.
The D50A is preferably 20 μm to 35 μm, and more preferably 25 μm to 35 μm.

In the present disclosure, “median diameter of volume standard of microcapsules” refers to particles on the large diameter side and the small diameter side when the particle diameter with which the volume total becomes 50% is divided into two based on the threshold value. The diameter that the sum of the volume of becomes equal.

The median diameter of the volume standard of the microcapsules in the microcapsules of the present disclosure is specifically measured by the following method.
First, a dispersion of microcapsules is obtained. The obtained dispersion is applied onto an arbitrary support and dried to form a coated film. The surface of the obtained coated film is photographed at a magnification of 150 with an optical microscope, and the sizes of all microcapsules in the range of 2 cm × 2 cm are measured and calculated.

-Number average wall thickness of microcapsules A-
The number average wall thickness of the microcapsule A depends on various conditions such as the material of the capsule wall, D50A, etc., but from the viewpoint of color development in a minute pressure range of 0.05 MPa or less, 0.01 μm to 0.15 μm Is preferable, and 0.02 μm to 0.10 μm is more preferable.

In the present disclosure, the wall thickness of a microcapsule refers to the thickness (μm) of the capsule wall of the microcapsule (for example, a resin film forming the microcapsule). The term "microcapsule" as used herein includes both microcapsule A and microcapsule B described later.
The number average wall thickness of microcapsules is the thickness (μm) of each capsule wall of five microcapsules determined by scanning electron microscopy (SEM), and the measured value of the thickness of capsule wall obtained (five) It refers to the number average value obtained by number average (that is, simple average) of the measured values).
Specifically, first, the microcapsule-containing liquid is applied onto any substrate (for example, the first substrate) and dried to form a coating film. A cross section of the obtained coated film is prepared, and the cross section is observed using an SEM. From the obtained SEM image, arbitrary 5 microcapsules are selected. The cross sections of the five selected microcapsules are observed to determine the thickness of the capsule wall in each of the five microcapsules. The measured values of the thickness of the capsule wall (five measured values) are number-averaged, and the obtained number-average value is taken as the number average wall thickness of the microcapsules.

The ratio of the number average wall thickness of the microcapsule A to the D50A of the microcapsule A (that is, the number average wall thickness / D50A ratio) is 1.0 from the viewpoint of color development in a minute pressure range of 0.05 MPa or less × 10 ⁻³ to 4.0 × 10 ⁻³ is preferable, and 1.3 × 10 ⁻³ to 2.5 × 10 ⁻³ is more preferable.

[Microcapsule B]
The microcapsule B contains a solvent having a melting point or a pour point of 30 ° C. or less (specific solvent) and a polar organic compound having a melting point of more than 30 ° C. (specific polar organic compound) and an electron donating dye precursor as a color forming component It is a microcapsule which does not contain. The microcapsules B may further contain auxiliary solvents, additives and the like, if necessary.

The microcapsule B has a function as a dummy capsule which suppresses the destruction of the microcapsule A, and the specific polar organic compound and the specific solvent which are released out of the capsule when the microcapsule B is broken, the present disclosure The measurement performance of the pressure measurement material is further improved.

-Solvent with melting point or pour point below 30 ° C-
The microcapsules B enclose a solvent (specific solvent) having a melting point or a pour point of 30 ° C. or less.
The specific solvent contained in the microcapsule B may be only one type, or two or more types. The specific solvent can function as an oil component.

As a specific solvent which microcapsule B contains, it can apply as an oil ingredient which microcapsule B contains, and if melting | fusing point or pour point is 30 degrees C or less, there will be no restriction | limiting in particular. The specific solvent is a solvent capable of dissolving or dispersing the specific polar organic compound.
When using the pressure measurement material of the present disclosure that the melting point or pour point of the specific solvent is 30 ° C. or less, for example, room temperature (the most versatile measurement environment (specifically, a recommended measurement environment)) When used in a temperature environment near 25 ° C., the inclusion of the microcapsule B in the pressure measurement material is in a state of having fluidity.

The fact that the melting point or pour point of the specific solvent is 30 ° C. or less can be judged by whether or not the inclusions of the microcapsules are visually fluid at 30 ° C. The fact that the microcapsule inclusions are in a fluid state is an indicator that the melting point or the pour point of the specific solvent is 30 ° C. or less.
When performing more detailed measurement, it can confirm, for example by the test method of JIS K 2269 (1987).
When two or more specific solvents are contained, the melting point or pour point of the specific solvent may be confirmed by visual observation at 30 ° C. whether it is liquid or not in a state where two or more of the specific solvents are mixed.
In the case where the specific solvent is a commercially available product put on the market, the literature value can be used as the melting point or the pour point when a literature value such as a catalog value exists.

Specifically as a specific solvent which microcapsule B contains, the compound whose melting | fusing point or pour point is 30 degrees C or less is mentioned among the compounds mentioned above as a solvent which can be included in microcapsule A. From the viewpoint of color forming property and solubility or dispersibility of the specific polar organic compound, diarylalkane compounds such as 1-phenyl-1-xylylethane (melting point: ≦ −50 ° C.), aliphatic hydrocarbons such as isoparaffin, etc. are preferable .
A commercial item can be used as a specific solvent. IP Solvent 1620 (synthetic isoparaffin, Idemitsu Kosan Co., Ltd., pour point: <−70 ° C.), IP Solvent 2835 (synthetic isoparaffin, Idemitsu Kosan Co., Ltd., pour point: -70 ° C), Hysol (registered trademark) SAS 296 (a mixture of 1-phenyl-1-xylyl ethane and 1-phenyl-1-ethylphenyl ethane, pour point: -47.5 ° C, Shin Nippon Oil Co., Ltd.), etc. Can be mentioned.

The mass ratio (specific solvent: specific polar organic compound) of the specific solvent and the specific polar organic compound to be described later, which is encapsulated in the microcapsule B (specific solvent: specific polar organic compound), is from the viewpoint of the effect expression expected for the specific polar organic compound. There is no particular limitation as long as the inside is fluid. For example, when the solubility of the specific solvent in the specific polar organic compound is high, the ratio of the specific solvent can be reduced in the mass ratio of the specific solvent to the specific polar organic compound. The mass ratio may be set in consideration of the balance between the solubility of the specific solvent in the specific polar organic compound and the viscosity of the specific solvent in the specific polar organic compound dissolved state.

-Polar organic compounds with a melting point above 30 ° C-
The microcapsule B encloses a polar organic compound (specific polar organic compound) having a melting point of more than 30 ° C.
The number of the specific polar organic compounds contained in the microcapsules B may be only one or two or more.
In the microcapsule B, the content of the specific polar organic compound is not particularly limited as long as the inside of the microcapsule B has fluidity. The mass ratio of the specific solvent to the specific polar organic compound is appropriately set in consideration of the balance between the solubility of the specific solvent in the specific polar organic compound and the viscosity of the specific solvent in the specific polar organic compound dissolved state. Good.

The specific polar organic compound encapsulated by the microcapsule B is an organic compound having a melting point of more than 30 ° C. and having polarity, which is a pressure or pressure using a color reaction between the electron donating dye precursor and the developer. In the measurement of distribution, a compound which contributes to the improvement of measurement performance such as sensitivity and color development can be selected.

The melting point of the specific polar organic compound can be confirmed by a general method (capillary method) as a visual melting point measurement method. Specifically, it can be confirmed by the melting point measurement method described in JIS K6220-1 (2015).

In the present disclosure, a polar organic compound means a compound having at least one atom selected from an oxygen atom, a nitrogen atom, and a sulfur atom.
Specific examples of the partial structure having at least one atom selected from an oxygen atom, a nitrogen atom, and a sulfur atom in the specific polar organic compound include, for example, an amide bond, a urethane bond, a urea bond, and an ether bond. And an ester bond, a sulfonyl bond, a sulfonamide group, an amino group, a hydroxy group, a carboxy group, a sulfo group and the like. These partial structures may be contained alone or in combination of two or more in the molecular structure of the polar organic compound.

As a specific polar organic compound, a compound (ie, a sensitizer) which accelerates a color development reaction between an electron donating dye precursor and a developer for causing the electron donating dye precursor to develop color, or an electron donating dye precursor It is preferable that it is a compound (that is, a developer) having a color developing ability to cause

When the microcapsule B contains a developer, the pressure measurement material of the present disclosure is to combine both the developer not contained in the microcapsule and the microcapsule B containing a developer. Is preferred. It is preferable to use microcapsules B containing a color developing agent together with a color developing agent not contained in the microcapsules, because an effect of improving the color developing ability can be obtained and undesired color development can be suppressed.

Among the specific organic compounds that can function as sensitizers, among the polar organic compounds known as sensitizers that can promote the reaction between the electron donating dye precursor and the electron donating dye precursor, the melting point exceeds 30 ° C. Compounds of Such a specific organic compound may be selected from compounds used as a sensitizer in applications of pressure-sensitive copying paper or thermosensitive recording paper. Moreover, you may use a commercial item as a specific organic compound which can function as a sensitizer.

As a specific organic compound which can function as a sensitizer, a compound having an amide bond, a compound having a sulfonamide group, a compound having a urea bond, a compound organic compound having a urethane bond, and the like are preferably mentioned.

Among these, as a specific organic compound which can function as a sensitizer, a compound having an amide bond is preferable, and a compound having an aliphatic group and an amide bond (hereinafter also referred to as a fatty acid amide) is more preferable. And compounds having an alkyl group and an amide bond (hereinafter also referred to as saturated fatty acid amides) are more preferable.
From the viewpoint of diffusion and compatibility, compounds having an alkyl group having 12 or more carbon atoms and an amide bond are particularly preferable. Examples of the compound having an alkyl group having 12 or more carbon atoms and an amide bond include the examples described later as specific examples of the saturated fatty acid amide, and among these, stearic acid amide is particularly preferable.

Examples of specific organic compounds that can function as sensitizers include fatty acid amides described in JP-A-5-10485 (specifically, long chain fatty acid amides having 16 or more carbon atoms in total, N having 20 or more carbon atoms in total. A compound having a molecular weight of 250 or more selected from -alkyl substituted long chain fatty acid amides and N, N-dialkyl substituted long chain fatty acid amides having 26 or more carbons in total.
In addition, as other examples of the specific organic compound which can function as a sensitizer, a compound described in paragraph 0031 of JP-A 06-210948, a compound described in paragraph 0045 of International Publication WO 2013/141224 A1, and The compounds described in paragraph 0063 of WO 2013/065704 A1 and the like can be mentioned.

Specific examples of the specific organic compound that can function as a sensitizer include the compounds described above including the compounds described above, but are not limited thereto. The melting points of the compounds exemplified below are all over 30 ° C.

Saturated fatty acid amide (eg, lauric acid amide, palmitic acid amide, stearic acid amide, behenic acid amide, hydroxystearic acid amide etc.), unsaturated fatty acid amide (eg, oleic acid amide, erucic acid amide etc.), N-substituted fatty acid An amide (eg, N-oleyl palmitic acid amide, N-stearyl stearamide, N-stearyl oleic acid amide, N-oleyl stearic acid amide, N-stearyl erucic acid amide, etc.), methylol amide (eg, methylol stearic acid amide) Etc.), saturated fatty acid bisamides (eg, methylenebisstearic acid amide, ethylenebiscapric acid amide, ethylenebislauric acid amide, ethylenebisstearic acid amide, ethylenebishydroxystearic acid amide, ethylene bisbe Acid amide, hexamethylene bisstearic acid amide, hexamethylene bisbehenic acid amide, hexamethylene hydroxystearic acid amide, N, N'-distearyl adipic acid amide, N, N'-distearyl adipic acid amide, N, N '-Distearyl sebacic acid amide etc.), unsaturated fatty acid bisamides (eg ethylene bis oleic acid amide, ethylene bis erucic acid amide, hexamethylene bis oleic acid amide, N, N'-dioleyl adipic acid amide, N, N '-Dioleyl sebacic acid amide etc.), aromatic bisamides (eg m-xylylene bis-stearic acid amide, m-xylylene bis-hydroxystearic acid amide, N, N'-stearyl isophthalic acid amide etc.), fatty acids Esteramides (eg, stearoamide) Stearate, etc.),

β-Naphthyl benzyl ether, N-stearyl urea, N, N′-distearyl urea, β-naphthoic acid phenyl ester, 1-hydroxy-2-naphthoic acid phenyl ester, 2- (p-methylbenzyloxy) naphthalene, 2 -Benzyloxynaphthalene, 1,4-dimethoxynaphthalene, 1-methoxy-4-benzyloxynaphthalene, N-stearoylurea, 1,2-bis (3-methylphenoxy) ethane, 1,2-diphenoxyethane, 1- Phenoxy-2- (4-chlorophenoxy) ethane, 1,2-diphenoxymethylbenzene, 1,4-butanediol phenyl ether, dibenzyl terephthalate, dimethyl terephthalate, oxalic acid dibenzyl ester, oxalic acid di (4- Chlorobenzyl) ester, di (oxalic acid) (Methyl benzyl) ester, methyl 4-hydroxybenzoate, benzyl 4-hydroxybenzoate, 4-hydroxybenzoic acid (4'-chlorobenzyl), ethyl 1,2-bis (4'-hydroxybenzoate), 1,5 -Bis (4'-hydroxybenzoic acid) pentyl, 1,6-bis (4'-hydroxybenzoic acid) hexyl, 4,4'-dimethoxybenzophenone, 4,4'-dichlorobenzophenone, 4,4'-difluorobenzophenone , Diphenyl sulfone, 4,4′-dichlorodiphenyl sulfone, 4,4′-difluorodiphenyl sulfone, 4,4′-dichlorodiphenyl disulfide, diphenylamine, 2-methyl-4-methoxydiphenylamine, N, N′-diphenyl- p-phenylenediamine, 1- (N-phenylamino) naphthalene, 1, -Diphenyl-1,3-propanedione, N-stearyl-N '-(2-hydroxyphenyl) urea, N-stearyl-N'-(3-hydroxyphenyl) urea, N-stearyl-N '-(4-) Compounds such as hydroxyphenyl) urea are mentioned.

As a specific organic compound capable of functioning as a developer, among electron-accepting compounds known as a developer for causing an electron donating dye precursor to develop a color, an electron accepting compound having a melting point of more than 30 ° C. can be mentioned. Such an electron accepting compound may be selected from compounds used in pressure sensitive copying paper or thermosensitive recording paper applications. Moreover, you may use a commercial item as a specific organic compound which can function as a color developer.

Among these, from the viewpoint of reactivity and diffusivity, the specific organic compound capable of functioning as a developer is selected from the group consisting of salicylic acid compounds, salts of salicylic acid compounds, phenolic compounds and sulfonamide compounds. At least one is preferred.
The salicylic acid compound means a compound having a partial structure derived from salicylic acid in the molecular structure. The phenolic compound means a compound having a partial structure derived from phenol in the molecular structure. The sulfonamide type compound means a compound having a sulfonamide group in the molecular structure.
Specific examples of the specific organic compound that can function as a developer in the pressure measurement material of the present disclosure will be described later.

From the viewpoint of reactivity, salts of salicylic acid type compounds or phenolic compounds are more preferable, and as salts of salicylic acid type compounds, metal salts of 3,5-disubstituted salicylic acid derivatives are preferable, and 3,5-diaralkyl substituted salicylic acid derivatives Are more preferred (zinc salts, nickel salts, aluminum salts, calcium salts etc.), and zinc 3,5-di-α-methylbenzyl salicylate is particularly preferred. As the phenolic compound, 2,4′-dihydroxydiphenyl sulfone or 4,4′-dihydroxydiphenyl sulfone is particularly preferable.

Specific examples of the specific organic compound that can function as a developer include electron-accepting compounds that can function as a developer among compounds described in each of the following documents, including the compounds described above. Is preferably mentioned. The melting points of the compounds exemplified below are all over 30 ° C.

Examples of the specific organic compound which can function as a developer include the compound described in paragraph 0046 of JP-A-2009-63512, the compound described in paragraph 0015 described in JP-A-6-183141, and The compound described in paragraph 0008 of 5-104850, the compound described in WO2013 / 141224, the compound described in paragraph 0032-0038 described in WO2011 / 108411, J. Am. Jpn. Soc. Color Mater. , 88 [11], 378-382 (2015), and the like.

Examples of specific organic compounds that can function as developers include the following compounds.
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-dimethylbenzyl) 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-5- (α, α-dimethylbenzyl) salicylic acid, 3,5-diethyl Benzylsalicylic acid, 3,5-di-α, α-dimethylbenzylsalicylic acid, 3,5-bis (α-methyl-α-tolylmethyl) salicylic acid, 3,5-bis (-α-methylbenzyl) salicylic acid, 3-α -Benzylated phenylethyl salicylic acid, 3-α-methyl-α-ethylpentyl-5-α, α-dimethylbenzyl salicylic acid, 3-cumyl-5-t-octylsalicylic acid, 3-cumyl-5-t-butylsalicylic acid 3-t-butyl-5-cumylsalicylic acid, 3,5-di-t-butylsalicylic acid, 3,5-di-t-octylsalicylic acid, 3,5-di-t-nonylsalicylic acid, 3,5- Bis (methylcumyl) salicylic acid, 3,5-biscumylsalicylic acid, 3-α-methylbenzyl-6-methylsalicylic acid, 3-α-benzylated phenylethyl-6-methylsa Tylic acid, 3-α-methyl-α-ethylpentyl-6-methylsalicylic acid, 3,5-bis (-α-benzylated phenylethyl) salicylic acid, 3,5-bis (benzylated benzyl) salicylic acid, 3,5- Bis (α-methylbenzyl) -6-methylsalicylic acid, 3-α-tolylethyl-6-methylsalicylic acid, 3,5-bis (α, α-dimethylbenzyl) -6-methylsalicylic acid, 3,5-di-t -Octyl-6-methylsalicylic acid, 3-α-dimethylphenylethyl-6-methylsalicylic acid, 3-α-ethylphenylethyl-6-methylsalicylic acid, 3-α-isopropylphenylethyl-6-methylsalicylic acid, 3-α-benzylated benzylphenylethyl-6-methylsalicylic acid, 3-α-methyl-α-ethylpentyl-6-ethylsalicylic acid, 3- Nonyl-6-methylsalicylic acid, 3-dodecyl-6-methylsalicylic acid, methyl salicylate, ethyl salicylate, isoamyl salicylate, isopentyl salicylate, phenyl salicylate, phenyl salicylate, 4-n-octyloxysalicylic acid, 4-n-butyloxysalicylic acid, 4-n-pentyloxysalicylic acid, 3-n-dodecyloxysalicylic acid, 3-n-ococtanoyloxysalicylic acid, 4-n-octyloxycarbonylaminosalicylic acid, 4-n-octanoyloxycarbonylaminosalicylic acid, carboxy-modified terpene A compound such as a phenolic resin, a salicylic acid resin which is a reaction product of 3,5-bis (α-methylbenzyl) salicylic acid and benzyl chloride, or a metal salt thereof (eg, zinc salt, nickel salt, aluminum Umushio, calcium salt),

2,4'-dihydroxydiphenylsulfone, 4,4'-dihydroxydiphenylsulfone, 2,2-bis (4-hydroxyphenyl) propane, 2,2-bis (hydroxyphenyl) butane, 2,2-bis (hydroxyphenyl) ) Pentane, 2,2-bis (hydroxyphenyl) heptane, 1,1-bis (4-hydroxyphenyl) cyclohexane, butyl bis (4-hydroxyphenyl) acetate, benzyl bis (4-hydroxyphenyl) acetate, bis (3 -Methyl-4-hydroxyphenyl) sulfone, 4-hydroxyphenyl-4'-methylphenylsulfone, 3-chloro-4-hydroxyphenyl-4'-methylphenylsulfone, 3,4-dihydroxyphenyl-4'-methylphenyl Sulfone, 4-isopropylphenyl-4'-hydroxy Phenyl sulfone, 4-hydroxy-4'-n-propoxydiphenyl sulfone, 4-hydroxy-4'-isopropoxydiphenyl sulfone, 4-hydroxy-4'-allyloxydiphenyl sulfone, bis (3-allyl-4-hydroxyphenyl ) Sulfone, 4-hydroxyphenyl-4'-benzyloxyphenyl sulfone, 4-isopropylphenyl-4'-hydroxyphenyl sulfone, bis (2-methyl-3-t-butyl-4-hydroxyphenyl) sulfide, 4-hydroxy Methyl benzoate, p-hydroxybenzoic acid benzyl ester, oligomer of hydroxybenzoic acid ester, 4-hydroxybenzoic acid (4'-chlorobenzyl), ethyl 1,2-bis (4'-hydroxybenzoic acid), 1,5 -Bis (4'-hydroxybenzoic acid) salt Nethyl, hexyl 1,6-bis (4'-hydroxybenzoate), dimethyl 3-hydroxyphthalate, stearyl gallate, lauryl gallate or its metal salt, salicylamide, salicylanilide, 4,4'-butylidene bis (6 -T-Butyl-3-methylphenol), 4,4'-bis (p-toluenesulfonylaminocarbonylamino) diphenylmethane, 4,4'-bis (o-toluenesulfonylaminocarbonylamino) diphenylmethane, 4,4'- Bis (p-toluenesulfonylaminocarbonylamino) diphenyl sulfide, 4,4'-bis (p-toluenesulfonylaminocarbonylamino) diphenyl ether, Np-toluenesulfonyl-N'-3- (p-toluenesulfonyloxy) phenyl Urea, N- (p-toluenes) Sulfonyl) -N '-(p-butoxycarbonyl) urea, N- (p-toluenesulfonyl) -N'-phenylurea, sulfonylurea derivative, N- (4-hydroxyphenyl) -4-toluenesulfonamide, N- Examples include (2-hydroxyphenyl) -4-toluenesulfonamide, N-phenyl-4-hydroxybenzenesulfonamide and the like.

-Volume based median diameter of microcapsule B (D50B)-
The volume-based median diameter (hereinafter, also referred to as "D50B") of the microcapsule B is preferably set according to the purpose such as increase in coloring density or suppression of coloring due to rubbing.
For example, the pressure measurement material of the present disclosure can be used as a high pressure measurement application that does not take into consideration too much suppression of color development by rubbing, and in this case, the volume based median diameter D50B of the microcapsule B is The smaller the value, the higher the color density in the high pressure area, and the higher the gradation.
On the other hand, in the measurement of a minute pressure of 0.05 MPa or less, the median diameter D50B of the volume standard of the microcapsule B is more than the median diameter D50A of the volume standard of the microcapsule A from the viewpoint of suppressing color formation by rubbing more. It is preferable to be large. Thereby, the effect of the color development suppression by rubbing by the microcapsule B is exhibited more effectively.

The D50B of the microcapsule B is preferably more than 40 μm and less than 150 μm. When D50B of the microcapsule B is more than 40 μm, the effect of suppressing color development by rubbing is more effectively exhibited.

-Number average wall thickness of microcapsules B-
The number average wall thickness of the microcapsule B depends on various conditions such as the material of the capsule wall and D50B, but from the viewpoint of more effectively exhibiting the function of the microcapsule B, 50 nm to 1000 nm is preferable, and 100 nm to 800 nm. Is more preferred.

The ratio of the number average wall thickness of the microcapsule B to the D50B of the microcapsule B (ie, the ratio of the number average wall thickness / D50B) is preferably 2.0 × 10 ⁻³ to 1.5 × 10 ⁻² And more preferably 2.5 × 10 ⁻³ to 8.0 × 10 ⁻³ .

The microcapsule B is a capsule which does not contain an electron donating dye precursor which is a coloring component.

The phrase "microcapsule B does not contain an electron donating dye precursor" means that the electron donating dye precursor is not substantially encapsulated in the microcapsule B, and is preferably 0 (zero) mass%. .

Microcapsule B contains the specific solvent and the specific polar organic compound, and does not contain the electron donating dye precursor, and has the same composition (capsule wall material etc.) as the microcapsule A, manufacturing conditions, capsule properties (Capsule wall thickness, particle size, etc.) can be formed.

The microcapsules B may further contain auxiliary solvents, additives and the like, if necessary. In this case, the same components as the auxiliary solvent, the additive and the like which can be contained in the microcapsule A can be selected as the components such as the auxiliary solvent and the additive which are contained in the microcapsule B.

The pressure measurement material of the present disclosure may include two or more microcapsules A having different median diameters, and may include two or more microcapsules B having different median diameters.
When two or more microcapsules A having different median diameters are included, the number of large-diameter microcapsules to be broken decreases as the pressure increases, and then the small-diameter microcapsules are broken to develop color, so that the pressure is high. As a result, the color density in the area is improved, and as a result, the density gradation in the high density area becomes a material for pressure measurement that is more excellent.

The method for producing the microcapsules A and the microcapsules B described above is not particularly limited, and a conventionally known method can be applied. For example, the methods described in paragraph Nos. 0036 to 0044 of JP-A No. 2009-019949 can be used. You can refer to the method.

Hereinafter, although the more specific structural example of the material for pressure measurement of this indication is demonstrated, the material for pressure measurement of this indication is not limited to the following aspects.

The pressure measurement material of the present disclosure preferably has a so-called two-sheet type form including a first material including a color former layer and a second material including a color developer layer.
The pressure measurement material of the present disclosure may have a so-called mono-sheet type form including a laminated structure including a color former layer and a developer layer on a substrate.
Hereinafter, among the materials for pressure measurement of the present disclosure, those having a form of two-sheet type are referred to as “material for pressure measurement A”, and those having a form of mono-sheet type are referred to as “material for pressure measurement B”. There is a case.

In the pressure measurement using the two-sheet type pressure measurement material A, the first material and the second material are in contact with the surface of the color former layer of the first material and the surface of the color developer layer of the second material. It piles up on. Specifically, the first material and the second material in the superposed state are disposed at a site where the pressure or pressure distribution is to be measured, and in this state, pressure is applied to the first material and the second material, Measurement can be performed.
The pressure measurement using the mono-sheet type pressure measurement material B is performed by placing the pressure measurement material B alone on the site where the pressure or pressure distribution is to be measured, and in this state, the pressure relative to the pressure measurement material B Can be done by adding
The pressure may be any of point pressure, linear pressure, and surface pressure.

In the pressure measurement material of the present disclosure, the pressure measurement material A, which is a two-sheet type, has a small difference in coloring density (difference in density) for identifying a minute pressure difference in a minute pressure range of 0.05 MPa or less. . For this reason, it can be particularly preferably used in the measurement of pressure or pressure distribution in the case where a surface pressure in which a differential pressure is difficult to catch is given.

In the pressure measurement material A or B, the microcapsule A is contained in the color former layer, and the microcapsule B is contained in at least one of the layers constituting the pressure measurement material A or B.
In the layer constituting the material for pressure measurement A or B, the layer containing the microcapsule B may contain only one type of microcapsule B, or two or more types (for example, 2 different in median diameter based on volume) Or higher) may be contained.

<Material A for pressure measurement (2-sheet type)>
When the pressure measurement material of the present disclosure is a two-sheet type (ie, pressure measurement material A), a first material in which a color former layer containing microcapsules A is disposed on a first substrate; And a second material in which a developer layer containing an electron accepting compound is disposed on a second substrate, wherein at least one of the first material and the second material contains the microcapsule B. Is preferred.

The details of the microcapsules A and the microcapsules B in the pressure measurement material A are as described above, and preferred embodiments are also the same.

In the pressure measurement material A, the first material may contain the microcapsules B, and the second material may contain the microcapsules B. Further, in the pressure measurement material A, both the first material and the second material may contain the microcapsule B, or one of the first material and the second material may contain the microcapsule B. Good.

In the pressure measurement material A, the layer containing the microcapsule B is a color former layer in the first material, a layer other than the color former layer in the first material, a developer layer in the second material, and the second material. It may be any layer other than the developer layer.
The pressure measurement material A is more preferably a mode in which the color former layer in the first material is a layer containing microcapsules B or a mode in which the developer layer in the second material is a layer containing microcapsules B .

Examples of the configuration of the layer containing microcapsules B in the pressure measurement material A include, but are not limited to, the following embodiment 1A to embodiment 4A. In addition, each aspect may further include any other layer (for example, an easy adhesion layer, etc.).

~ Aspect 1A ~
A first material having a color former layer containing microcapsules A and B on a first substrate, and a second material having a color developer layer containing a developer on a second substrate An embodiment having
~ Aspect 2A
On a first substrate, sequentially from the first substrate side, a color former layer containing microcapsules A, another layer containing microcapsules B, a first material provided, and a second substrate An embodiment having a second material provided with a developer layer containing a developer.
~ Aspect 3A ~
A first material in which another layer containing microcapsules B and a color former layer containing microcapsules A are disposed on the first substrate sequentially from the first substrate side, and on the second substrate The aspect which has the 2nd material which arrange | positioned the color developer layer in the
~ Aspect 4A ~
A first material in which a color former layer containing microcapsules A is disposed on a first substrate, and a second material in which a color developer layer comprising a developer and microcapsules B is disposed on a second substrate An embodiment having

When at least one of the color former layer in the first material or the color developer layer in the second material contains the microcapsule B, the microcapsule B from the viewpoint that the effect of suppressing color formation by rubbing is more effectively exhibited. Is preferably contained in the color former layer in the first material.

In the pressure measurement material A, D50A of the microcapsule A is preferably more than 10 μm and less than 40 μm, and D50B of the microcapsule B is preferably more than 40 μm and less than 150 μm. The preferred ranges of each of D50A and D50B are as described above.

When D50B of the microcapsule B is less than 150 μm, it is possible to further suppress unevenness of the layer containing the microcapsule B (for example, application unevenness in a mode in which the color former layer is formed by application). When microcapsules B are contained in the color former layer, and D50B is less than 150 μm, the coefficient of variation (CV value; coefficient of variation; particle size distribution; hereinafter, CV value) of the particle size distribution of the color former layer. Since it does not become too large, the gradation of color development is further improved. The CV value will be described later.

The pressure measurement material A only needs to show visible or readable concentration and concentration gradation when color is developed, but from the concentration after color development by applying pressure at 0.05 MPa, the pressure is 0.04 MPa It is preferable that the density difference (ΔD1) obtained by reducing the density after color development by the addition of.
The larger the value of the color developed ΔD1 derived from the color former layer, the more preferable, and it is 0.20 or more, so that the material for pressure measurement of the present disclosure gives a minute pressure of 0.05 MPa or less to cause color development In some cases, visible and readable density and density gradation can be reproduced better.
The color density is a value measured using a reflection densitometer (for example, RD-19I manufactured by Gladeg Macbeth).

Furthermore, the pressure measurement material A is superimposed on the color former layer of the first material by bringing the color developer layer of the second material having the same area as the color former layer of the first material into contact with the color former layer, It is preferable that the density difference (ΔD2) obtained by subtracting the density before rubbing from the color density after repeated rubbing movement of the first material 20 times with respect to the second material is suppressed to less than 0.02.
When ΔD2 is less than 0.02, color development to a visible or readable density due to rubbing or the like can be suppressed to a low level.
The smaller the value of ΔD 2, the more preferable, the case of less than 0.01 is more preferable, and the case of zero (that is, no color development) is more preferable.

Hereinafter, the first material and the second material in the pressure measurement material A will be described.

[First material]
The pressure measurement material A comprises a first material in which a color former layer containing microcapsules A containing an electron donating dye precursor is disposed on a first substrate.
The first material includes a first substrate and a color former layer disposed on the first substrate.

[First base material]
The shape of the first base material in the pressure measurement material A may be any of sheet, film, plate and the like.
When the pressure measurement material is a two-sheet type, the first base in the first material and the second base in the second material may be the same or different.

Specific examples of the first substrate include paper, plastic film, synthetic paper and the like.

Specific examples of paper include high-grade paper, medium-grade paper, paper, neutral paper, acid paper, recycled paper, coated paper, machine-coated paper, art paper, cast-coated paper, finely-coated paper, tracing paper, A recycled paper etc. can be mentioned.
Specific examples of the plastic film include polyester film such as polyethylene terephthalate film, cellulose derivative film such as cellulose triacetate, polyolefin film such as polypropylene and polyethylene, polystyrene film, and the like.
Specific examples of synthetic paper include those obtained by biaxially stretching polypropylene or polyethylene terephthalate to form a large number of microvoids (Yupo etc.), synthetic fibers such as polyethylene, polypropylene, polyethylene terephthalate, polyamide, etc. Are laminated on a part of the paper, one side or both sides, and the like.
Among them, plastic films and synthetic papers are preferable, and plastic films are more preferable, from the viewpoint of further increasing the color density generated by pressure.

[Color-agent layer]
The color former layer in the first material contains microcapsules A containing an electron donating dye precursor.
The color former layer may contain only one type of microcapsule A, or may contain two or more types. For example, two or more microcapsules A having different volume-based median diameters may be contained. The color former layer may further contain other components, if necessary.

In the first material, in addition to the microcapsule A which contributes to color development when pressure is applied, the color former layer does not contain an electron donating dye precursor, but contains a specific solvent and a specific polar organic compound, It is preferable to include microcapsules B that do not develop color under pressure, and it is more preferable to include microcapsules B (D50A <D50B) having a larger median diameter than the microcapsules A. When the coloring agent layer includes the microcapsule B, the microcapsule B is broken first to prevent the microcapsule A from being broken when an unexpected minute pressure is applied, and thus the unexpected color development can be suppressed to a low level. Furthermore, when the microcapsule A is broken, the sensitivity and the color developability are further improved by the specific solvent and the specific polar organic compound released to the outside of the microcapsule. Thereby, unnecessary color development due to rubbing and the like is suppressed, and the measurement performance is further improved.

The content (for example, the coating amount) in the color former layer of the electron donative dye precursor is 0.1 g / m ² or less in mass after drying from the viewpoint of enhancing the color developability in a minute pressure range of 0.05 MPa or less. 5 g / m ² is preferable, 0.1 g / m ² to 4 g / m ² is more preferable, and 0.2 g / m ² to 3 g / m ² is more preferable.

The content (coating amount in the case of coating) of the microcapsule A in the color former layer is preferably 50% by mass to 80% by mass, and more preferably 60% by mass to 75% by mass with respect to the total solid content of the color former layer. % Is more preferable.

When the color former layer contains microcapsules B, the content of the microcapsules B in the color former layer (coating amount in the case of coating) is 5% by mass to the total solid content mass of the color former layer 30% by mass is preferable, and 10% by mass to 25% by mass is more preferable.

The color former layer may contain other components other than the microcapsule A and the microcapsule B.
Other components include water-soluble polymeric binders (for example, fine powder of starch or starch derivative, buffer such as cellulose fiber powder, polyvinyl alcohol, etc.), hydrophobic polymeric binders (for example, vinyl acetate-based) Acrylic, styrene-butadiene copolymer latex, etc., surfactants, inorganic particles (for example, silica particles), fluorescent whitening agents, antifoaming agents, penetrants, ultraviolet absorbers, preservatives and the like.

Examples of the surfactant used in the color former layer include sodium alkylbenzene sulfonate (eg Neogen T from Dai-ichi Kogyo Seiyaku Co., Ltd.) which is an anionic surfactant, and poly which is a nonionic surfactant. Oxyalkylene lauryl ether (for example, Neugen LP70 of Dai-ichi Kogyo Seiyaku Co., Ltd., etc.) and the like can be mentioned.

Examples of the silica particles used in the color former layer include gas phase silica, colloidal silica and the like.
With regard to silica particles, examples of commercially available products that have been marketed include Snowtex series (for example, Snowtex (registered trademark) 30) of Nissan Chemical Industries, Ltd., and the like.

The CV value of the particle size distribution of all the particles contained in the color former layer is preferably 35% to 150%.
When the CV value is within the above range, the particle distribution in the color former layer, in particular the relative dispersion of the microcapsules, is small, so that the balance between the color developability against minute pressure and the color developability preventing by rubbing etc. is excellent It becomes.
The CV value is preferably 40% to 110%, and more preferably 40% to 80%.

In addition, CV value represents the relative variation of the particle | grains of a coloring agent layer, and is a value calculated | required from the following.
CV value (%) = standard deviation / arithmetic mean particle size × 100
The arithmetic mean particle size and the standard deviation are values calculated by photographing the surface of the color former layer with an optical microscope at a magnification of 150 and measuring the sizes of all microcapsules in the range of 2 cm × 2 cm.

Formation of color former layer
The color former layer in the pressure measurement material A applies (for example, applies) a coating liquid for forming a color former layer containing the components of the color former layer and the liquid component (for example, water) described above on the first substrate, for example. It can be formed by drying.
The coating solution for forming a color former layer can be prepared, for example, by preparing an aqueous dispersion of microcapsules A and, if necessary, mixing the aqueous dispersion of microcapsules A with other components.
When forming a color former layer containing two or more types of microcapsules A having different D50A etc., preferably, an aqueous dispersion is prepared for each of the two or more types of microcapsules A, and two types obtained Using the above aqueous dispersion of microcapsules A, a coating solution for forming a color former is prepared.

When the color former layer contains microcapsules B, the coating liquid for forming a color former layer for forming the color former layer is preferably prepared by respectively dispersing the aqueous dispersion of microcapsule A and the aqueous dispersion of microcapsule B Then, using the aqueous dispersion of microcapsules A, the aqueous dispersion of microcapsules B, and other components, a coating solution for forming a color former is prepared.

When the color forming agent layer is formed by applying a color forming agent layer forming coating solution on a substrate, the application can be performed by a known application method.
Examples of the coating method include a coating method using 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, a blade coater or the like.

There is no restriction | limiting in particular as thickness of a color-developing agent layer, According to the objective etc., it can select.
The thickness of the color former (when the microcapsule diameter is larger than the layer thickness, the thickness excluding the microcapsules exposed from the layer surface) is preferably 0.01 μm to 0.10 μm, and more preferably 0.02 μm to 0.07 μm.

[Second material]
The pressure measurement material of the present disclosure comprises a second material in which a developer layer containing an electron accepting compound is disposed on a second substrate.
The second material includes a second substrate and a developer layer disposed on the second substrate.

[Second base material]
As a 2nd base material, the thing similar to a 1st base material is mentioned.
In the pressure measurement material of the present disclosure, the material of the first base material and the material of the second base material may be the same as or different from each other.

[Color developer layer]
The developer layer contains at least an electron accepting compound that is a developer, and may optionally contain other components such as a binder, a pigment, and an additive. The developer referred to here does not include the developer encapsulated in the microcapsule.

As the electron accepting compound, inorganic compounds and organic compounds can be mentioned.
Specific examples of the inorganic compound include acid clay, activated clay, attapulgite, zeolite, bentonite, or a clay material such as kaolin.
Specific 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 salts of aromatic carboxylic acids, metal salts of carboxylated temperphenol resins are preferable, and acid clays, activated clay, kaolin, metal salts of aromatic carboxylic acids are preferred. More preferable.

Preferred specific examples of metal salts of aromatic carboxylic acids include 3,5-di-t-butylsalicylic acid, 3,5-di-t-octylsalicylic acid, 3,5-di-t-nonylsalicylic acid, 3,5-di-t-butylsalicylic acid -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-dimethylbenzyl) ) 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-(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 can be mentioned.

Among the specific organic compounds that can be contained in the microcapsule B, a compound that can function as a developer may be used as the developer included in the developer layer.

Content in the developer layer of the electron-accepting compound (weight case of applying the coating) ^{is, 0.1g / m 2 ~ 30g /} m 2 is preferable in dry weight. More preferably, in the case of the inorganic compound was ^{3g / m 2 ~ 20g / m} 2, in the case of organic compounds was ^{0.1g / m 2 ~ 5g / m} 2, more preferably, in the case of inorganic compound 5g It is from / m ² to 15 g / m ² , and in the case of an organic compound, from 0.2 g / m ² to 3 g / m ² .

The developer layer can be formed by preparing and forming a preparation liquid for forming a developer layer. The developer layer may be formed, for example, by applying a preparation solution for forming a developer layer on a support by a method such as coating and drying it.
The preparation liquid for forming a developer layer may be a dispersion liquid in which an electron accepting compound is dispersed in water or the like.
When the electron accepting compound is an inorganic compound, the dispersion liquid in which the electron accepting compound is dispersed can be prepared by mechanically dispersing the inorganic compound in water, and the electron accepting compound is an organic compound. In some cases, it can be prepared by mechanically dispersing the organic compound in water or dissolving it in an organic solvent.
For the details, the method described in JP-A-8-207435 can be referred to.

The obtained dispersion liquid of the electron accepting compound may be used as it is as a preparation liquid (for example, a coating liquid) for forming a developer layer for forming a color developer layer containing the electron accepting compound.

The developer layer may contain, in addition to the electron accepting compound described above, a binder, a pigment, and additives such as a brightening agent, an antifoaming agent, a penetrant, a preservative and the like.

It is also preferable that the developer layer contains the already described microcapsules B.
The specific polar organic compound contained in the microcapsule B contained in the developer layer may be a compound having a sensitizing ability or a compound having a color developing ability. One of the preferable embodiments is an embodiment in which the microcapsule B contains a compound having a sensitizing ability as the specific polar organic compound.

The details of the microcapsule B contained in the developer layer are as described above, and the preferred range is also the same.

When the developer layer contains microcapsules B, the content of the microcapsules B in the developer layer (coating amount in the case of application) is 5 with respect to the total solid content mass of the developer layer. % By mass to 30% by mass is preferable, and 10% by mass to 25% by mass is more preferable.

As a binder, for example, styrene-butadiene copolymer latex, vinyl acetate latex, acrylic ester latex, polyvinyl alcohol, polyacrylic acid, maleic anhydride-styrene copolymer, starch, casein, gum arabic, gelatin And synthetic or natural polymeric substances such as carboxymethylcellulose, methylcellulose and the like.

As the pigment, for example, kaolin, calcined kaolin, kaolin aggregate, ground calcium carbonate, light calcium carbonate of various forms (rice granular, horny, spindle-like, iga-like, spherical, aragonite columnar, amorphous, etc.) And talc, rutile type, or anatase type titanium dioxide and the like.

In the case of forming a color developer layer by applying a preparation liquid for forming a color developer layer, the coating can be performed by a known coating method, and the same coating method as in the case of forming the color former layer described above Can be applied.

[Easy adhesion layer]
The first substrate or the second substrate may be a substrate with an easy adhesion layer.
It is preferable that the first material has a first base, and an easy adhesion layer and a coloring agent layer disposed from the first base side. The easily adhesive layer is preferably provided to improve the adhesion between the first base material and the color former layer.
In addition, when the composition containing the microcapsules is applied to the easily adhesive layer and dried, the microcapsules electrostatically interact with the easily adhesive layer (for example, hydrogen bond) and suppress aggregation. There is. This improves the effect that the microcapsules are broken by a minute pressure when measuring pressure.

The easy adhesion layer may be a layer containing a urethane polymer and / or a blocked isocyanate.

There is no restriction | limiting in particular as a thickness of an easily bonding layer, According to the objective etc., it can select.
The thickness of the easy adhesion layer is preferably 0.005 μm to 0.2 μm, and more preferably 0.01 μm to 0.1 μm.

<Material for pressure measurement of mono-sheet type>
When the pressure measurement material of the present disclosure is a mono-sheet type (i.e., pressure measurement material B), the pressure measurement material B contains an electron accepting compound on the substrate sequentially from the substrate side. It is preferable to have a laminated structure including a coloring agent layer and a color former layer containing microcapsules A, and the microcapsule B is contained in at least one layer contained in the laminated structure.
The layer of the laminated structure containing the microcapsules B may be any of a color former layer, a developer layer, or another layer other than the color former layer and the developer layer.

Examples of the configuration of the layer containing microcapsules B in the pressure measurement material B include, but are not limited to, the following embodiment 1B to embodiment 5B. In addition, each aspect may further include any other layer (for example, an easy adhesion layer, etc.).

-Aspect 1 B-
The aspect which arrange | positions the color-developing agent layer containing the microcapsule A and the microcapsule B, and the color developer layer containing a color developer sequentially from a base material side on a base material.
-Aspect 2B
The aspect which arrange | positions the color developer layer containing a color developer, another layer containing microcapsule B, and the color developing agent layer containing microcapsule A sequentially from a base material side on a base material.
~ Aspect 3B ~
An embodiment in which a developer layer containing a developer and microcapsules B and a color former layer containing microcapsules A are arranged on a substrate sequentially from the substrate side.
~ Aspect 4B ~
An embodiment in which a developer layer containing a developer and a color former layer containing microcapsules A and B are disposed on a substrate sequentially from the substrate side.
~ Aspect 5B ~
The aspect which arrange | positions the color developer layer containing a color developer, the color developing agent layer containing the microcapsule A, and another layer containing the microcapsule B sequentially from a base material side on a base material.

One of the preferred embodiments of the mono-sheet type pressure measurement material B is that a developer layer containing a developer contains microcapsules B containing a specific polar organic compound having a sensitizing ability. is there.
In addition, an embodiment in which the microcapsules A and the microcapsules B are in the same layer is also preferable because the diffusion and compatibility of the compound contributing to the color forming reaction can be expected to be improved.

As a base material in the material B for pressure measurement, the thing similar to the 1st base material in the material A for pressure measurement is mentioned.
The details of the microcapsules A and the microcapsules B in the pressure measurement material B are as described above, and preferred embodiments are also the same.
Details of each layer such as a color former layer, a developer layer, and another layer containing microcapsules B contained in the material for pressure measurement B are the color material layer contained in the material for pressure measurement B, a developer layer, microcapsules It is the same as the matter described as each layer such as another layer containing B.
In addition, the preparation of the material for pressure measurement B may be the same as the preparation of the material for pressure measurement A except that each layer such as a color former layer and a developer layer is formed on a single substrate. it can.

Hereinafter, the present invention will be more specifically described by way of examples. However, the present invention is not limited to the following examples as long as the gist thereof is not exceeded. In addition, unless there is particular notice, "%" and "part" are mass references.

Example 1
Preparation of Microcapsule A1 Containing Liquid
A solution A was obtained by dissolving 20 parts of the following compound (A), which is an electron donating dye precursor, in 57 parts of a linear alkylbenzene (JX Energy Co., Ltd., grade alkene L).
The obtained solution A was stirred, and N, N, N ', N'-tetrakis dissolved in 15 parts of synthetic isoparaffin 1 (Idemitsu Kosan Co., Ltd., IP solvent 1620) and 1.2 parts of ethyl acetate were mixed therein. A solution B was obtained by adding 0.2 parts of (2-hydroxypropyl) ethylenediamine (manufactured by Adeka Co., Ltd., Adeka Polyether EDP-300).
The resulting solution A is stirred, to which 1.2 parts of trimethylolpropane adduct of tolylene diisocyanate (DIC Corporation, Bernock D-750) dissolved in 3 parts of ethyl acetate is added, and solution C is added. I got
Next, the above solution C was added to a solution of 9 parts of polyvinyl alcohol (PVA-205, Kuraray Co., Ltd.) dissolved in 140 parts of water, and the mixture was emulsified and dispersed. To the obtained emulsion, 340 parts of water was added, and the mixture was heated to 70 ° C. with stirring, and stirred for 1 hour, and then cooled. Water was further added to the liquid after cooling to adjust the solid concentration.
Thus, a microcapsule A1-containing liquid (solid content concentration: 19.6%) containing microcapsule A1 containing an electron donating dye precursor was obtained. The microcapsule A1 is included in the microcapsule A in the present disclosure.

The microcapsule A1 contained in the microcapsule A1-containing solution has a median diameter (D50A) of 30 μm, a number average wall thickness of 0.054 μm, and a δ ^A / D 50A of 1.8. It was x 10 ^-3 .

The median diameter (D50A) and the number average wall thickness of the microcapsule A1 were calculated as follows.
First, the microcapsule A1-containing liquid was coated on a 75 μm-thick polyethylene terephthalate (PET) sheet with an easy-adhesion layer (Toyobo Co., Ltd., Cosmo Shine (registered trademark) A4300) and dried to obtain a coated film.
The D50A of the microcapsule A1 was obtained by photographing the surface of the obtained coated film with an optical microscope at a magnification of 150 and measuring the equivalent circular diameter of all the microcapsules A1 in the range of 2 cm × 2 cm, based on the obtained results. Calculated.
The number average wall thickness of the microcapsule A1 is obtained by preparing a cross section of the coating film, selecting five microcapsules A1 from the cross section, and measuring the thickness (μm) of each capsule wall with a scanning electron microscope (SEM) It calculated | required by calculating | requiring and averaging the obtained value.

<Preparation of Microcapsule B1 Containing Liquid (1)>
Synthetic isoparaffin 1 (Idemitsu Kosan Co., Ltd., IP Solvent 1620, specified solvent, pour point: <−70 ° C.) 15 parts and N, N, N ′, N′-tetrakis (2- Aromatic oil (Hysol (registered trademark) SAS 296 (1-phenyl-1-xylyl ethane and 1-phenyl) stirring with hydroxypropyl) ethylenediamine (Adeca, Inc., Adeka polyether EDP-300) and 0.4 parts. A solution D was obtained by adding it to 78 parts of a mixture with -1-ethylphenylethane, Shin Nippon Oil Co., Ltd., a specific solvent, and a pour point of <−47.5 ° C.).
The obtained solution D was stirred, and 3 parts of trimethylolpropane adduct of tolylene diisocyanate (DIC Corporation, Burnock D-750) dissolved in 107 parts of ethyl acetate was mixed with stearic acid amide (Nippon Kasei Co., Ltd.) A solution E was obtained by adding 5 parts of Amide AP-1, a specified polar organic compound, melting point: 101 ° C., and the like.
Next, the above solution E was added to a solution of 69 parts of polyvinyl alcohol (PVA-205, Kuraray Co., Ltd.) dissolved in 140 parts of water, and the mixture was emulsified and dispersed. To the obtained emulsion, 340 parts of water was added, and the mixture was heated to 70 ° C. with stirring, and stirred for 1 hour, and then cooled. Water was further added to the liquid after cooling to adjust the concentration.

As described above, a microcapsule B1 -containing liquid (a solid containing a microcapsule B1 which contains an aromatic oil and isoparaffin as a specific solvent and a stearic acid amide as a specific polar organic compound and does not contain an electron donating dye precursor Partial concentration 19.6%) was obtained. The microcapsule B1 is included in the microcapsule B in the present disclosure. The specific solvent in the microcapsule B1 contains an aromatic oil as a main solvent.
Stearic acid amide is a specific polar organic compound that functions as a sensitizer.

The microcapsule B1 had a median diameter (D50B) at volume standard of 55 μm, a number average wall thickness of 0.10 μm, and δB / D50B of 1.8 × 10 ⁻³ .
The measurement method of D50B and the number average wall thickness of the microcapsule B1 was the same as the measurement method of D50A and the number average wall thickness of the microcapsule A1, respectively.

Preparation of Coating Solution (1) for Forming Coloring Agent Layer>
18 parts of microcapsule A1 containing liquid obtained above, 2 parts of microcapsule B1 containing liquid obtained above, 63 parts of water, 1.8 parts of colloidal silica (Nissan Chemical Industries, Ltd., Snowtex (registered trademark) 30), 1.8 parts of a 10% aqueous solution of carboxymethylcellulose Na (Daiichi Kogyo Seiyaku Co., Ltd., Cellogen 5A), 30 parts of a 1% aqueous solution of carboxymethylcellulose Na (Daiichi Kogyo Seiyaku Co., Ltd., Cellogen EP), sodium alkylbenzene sulfonate Mix 0.3 parts of a 15% aqueous solution (Daiichi Kogyo Seiyaku Co., Ltd., Neogen T) and 0.8 parts of a 1% aqueous solution of Neugen LP 70 (Daiichi Kogyo Seiyaku Co., Ltd.) and stir for 2 hours Thus, a coating solution for forming a color former layer (1) was obtained.

<Preparation of the first material>
The resulting color former layer forming coating solution (1) is formed on a 75 μm thick polyethylene terephthalate (PET) sheet with an easy-adhesion layer (Toyobo Co., Ltd., Cosmo Shine (registered trademark) A4300, first base material) The solution was applied by a bar coater such that the mass after drying was 2.8 g / m ² and dried to form a color former layer.
By the above, the 1st material by which the color development agent layer containing microcapsule A1 and microcapsule B1 was arranged on the 1st substrate was obtained.

Preparation of Coating Solution (1) for Colorant Layer Formation>
10 parts of zinc 3,5-di-α-methylbenzyl salicylate which is an electron accepting compound, 100 parts of calcium carbonate, 1 part of sodium hexametaphosphate, and 200 parts of water, using a sand grinder, the average particle size of all particles It disperse | distributed so that 2 micrometers might be set, and the dispersion liquid was obtained.
An electron accepting property is obtained by adding 100 parts of a 10% aqueous solution of polyvinyl alcohol (PVA-203, Kuraray Co., Ltd.), 10 parts of a styrene-butadiene latex as a solid content, and 450 parts of water to the obtained dispersion. A coating solution (1) for developer layer formation containing a compound was prepared.

<Preparation of Second Material>
The coating solution for developer layer formation (1) obtained above is applied on a 75 μm thick polyethylene terephthalate (PET) sheet (second base material) so that the solid content coating amount is 4.0 g / m ² And dried to form a developer layer.
Thus, a second material was obtained in which a developer layer containing zinc 3,5-di-α-methylbenzyl salicylate, which is an electron accepting compound, was disposed on the second base material.

Thus, a two-sheet type pressure measurement material (1) including the first material and the second material was obtained.

Example 2
Example 1 except that 5 parts of stearic acid amide was changed to 5 parts of zinc 3,5-di-α-methylbenzyl salicylate (melting point: 125 ° C.) in the preparation of the microcapsule B1-containing liquid of Example 1. A two-sheet type pressure measurement material (2) was produced in the same manner as in.

[Example 3]
In the same manner as in Example 1 except that 5 parts of stearic acid amide was changed to 5 parts of 2,4-dihydroxydiphenyl sulfone (melting point: 184 ° C.) in the preparation of the microcapsule B1-containing liquid of Example 1. A two-sheet type pressure measurement material (3) was produced.

Example 4
Example 1 and Example 1 were repeated except that 5 parts of stearic acid amide was changed to 5 parts of 4-hydroxy-4'-isopropoxydiphenyl sulfone (melting point: 128 ° C.) in the preparation of the microcapsule B1-containing liquid of Example 1. Similarly, a two-sheet type pressure measurement material (4) was produced.

[Example 5]
Preparation of Coating Solution (2) for Forming Coloring Agent Layer
A coloring agent layer is prepared in the same manner as the coloring agent layer forming coating solution (1) except that 2 parts of the microcapsule B1 containing solution is not used in the preparation of the coloring agent layer forming coating solution (1) of Example 1. A forming coating solution (2) was prepared.

<Preparation of the first material>
The coating solution (2) for forming a color former layer obtained above was formed into a 75 μm-thick polyethylene terephthalate (PET) sheet with an easy-adhesion layer (Toyobo Co., Ltd., Cosmo Shine (registered trademark) A4300, first base material) On the top, it apply | coated by the bar coater so that the mass after drying might be 2.6 g / m < ² >, it was made to dry, and the color former layer was formed.
By the above, the 1st material by which the color development agent layer which contains microcapsule A and does not contain microcapsule B on the 1st substrate was obtained.

<Preparation of Second Material>
Coating solution for developer layer formation (Example 1) in the same manner as in Example 1 except that 40 parts of microcapsule B1 containing solution was further added in preparation of coating solution (1) for developer layer formation in Example 1 2) was prepared. A second material was produced in the same manner as in Example 1 except that the developer layer forming coating solution (2) was used in place of the developer layer forming coating solution (1) in Example 1.

Thus, a two-sheet type pressure measurement material (5) including the first material and the second material was obtained.

[Example 6]
The same coating solutions as the coating solution for a developer layer (1) prepared in Example 1 and the coating solution for a color former layer (1) were respectively prepared.
Coating amount of coating solution (1) for developer layer on solid layer with 75 μm thick polyethylene terephthalate (PET) sheet with easy adhesion layer (Toyobo Co., Ltd., Cosmo Shine (registered trademark) A4300, base material) Was applied by a bar coater at 4.0 g / m ² to form a developer layer. Next, the color developing agent layer coating liquid (1) was applied on the color developing agent layer at a solid content coating amount of 2.8 g / m ^{2 by} a bar coater to form a color developing agent layer.
Thus, a mono-sheet type pressure measurement material (6) was obtained, in which two layers of a developer layer and a color former layer were sequentially laminated on the substrate in this order from the substrate side.

Thus, a mono-sheet type pressure measurement material (6) including the color former layer and the developer layer was obtained.

[Example 7]
A microcapsule B2 containing microcapsules B2 is prepared in the same manner as in Example 1 except that the emulsification conditions are changed so that the capsule particle size becomes 30 μm in the preparation of the microcapsule B1 containing liquid (1) of Example 1. A containing solution (solid content concentration 19.6%) was prepared.
The microcapsule B2 contained in the microcapsule B2 containing solution has a median diameter (D50A) at a volume standard of 30 μm, a number average wall thickness of 0.054 μm, and δ ^A / D 50A of 1.8 It was x 10 ^-3 .

In preparation of coating liquid (1) for color-developer layer formation of Example 1, it changed to 2 parts of microcapsule B1 containing liquid (1), and it was the same as that of Example 1 except using 2 parts of microcapsule B2 containing liquid. The coating solution (3) for forming a color former layer was prepared.
A first material and a second material are prepared in the same manner as in Example 1 except that the color former layer forming coating liquid (1) is replaced with the color former layer forming coating liquid (3) in Example 1. did.

Thus, a two-sheet type pressure measurement material (7) including the first material and the second material was obtained.

[Example 8]
In preparation of the microcapsule B1-containing liquid (1) of Example 1, 15 parts of synthetic isoparaffin 1 is replaced with synthetic isoparaffin 2 (Idemitsu Kosan Co., Ltd., IP solvent 2835, specific solvent, pour point: <−60 ° C.) A microcapsule B1 -containing liquid (2) containing microcapsules B2 was prepared in the same manner as in Example 1 except that the amount was changed to 15 parts.

In the preparation of the coating solution (1) for forming a color former layer of Example 1, the example was used except that 2 parts of the microcapsule B1 containing liquid (2) was used instead of 2 parts of the microcapsule B1 containing liquid (1) In the same manner as in 1, a coating solution (4) for forming a color former layer was prepared.
A first material and a second material are produced in the same manner as in Example 1 except that the color former layer forming coating liquid (1) is replaced with the color former layer forming coating liquid (4) in Example 1. did.

Thus, a two-sheet type pressure measurement material (8) including the first material and the second material was obtained.

Comparative Example 1
Preparation of Microcapsule B3 Containing Liquid
A microcapsule B3-containing liquid (containing microcapsules B3) in the same manner as in the preparation of the microcapsule B1-containing liquid except that 5 parts of stearic acid amide was not used in the preparation of the microcapsule B1-containing liquid of Example 1 The solid concentration was 19.6%).

Preparation of Coating Solution (C1) for Forming Coloring Agent Layer
Coating liquid (1) for coloring agent layer formation except preparation of coating liquid (1) for coloring agent layer formation of Example 1 having changed 2 parts of microcapsule B 1 containing liquid into 2 parts of microcapsule B 3 containing liquid In the same manner as in the above, a coating solution (C1) for forming a color former layer was prepared.

<Preparation of the first material>
The coating solution (C1) for forming a color former layer obtained above was formed into a 75 μm thick polyethylene terephthalate (PET) sheet with an easy-adhesion layer (Toyobo Co., Ltd., Cosmo Shine (registered trademark) A4300, first base material) It coated by a bar coater so that the mass after drying might be 2.8 g / m < ² > on it, and it was made to dry, and the coloring agent layer was formed.
Thus, a first material was obtained in which a color former layer containing microcapsules A1 and microcapsules B3 containing no specific organic compound was disposed on the first base material.

<Preparation of Second Material>
The second material was produced in the same manner as in Example 1.

By the above, a pressure measurement material (9) for comparison of two sheets type provided with the first material and the second material was obtained.

Comparative Example 2
<Preparation of the first material>
A first material is prepared in the same manner as in Example 5 except that in the preparation of the first material of Example 5, the color forming agent layer is formed on the first substrate using the coating solution for forming a color forming agent layer (2). Was produced.

The second material was produced in the same manner as in Example 1.

From the above, a pressure measurement material (10) for comparison of two sheets type provided with the first material and the second material was obtained.

Comparative Example 3
In the preparation of the first material of Example 6, two layers of the developer layer and the color former layer are sequentially formed in the same manner as in Example 6 except that the specific polar organic compound is not used. A laminated mono-sheet type pressure measurement material (11) was obtained.

<Measurement and evaluation>
The following measurements and evaluations were performed using the obtained materials for pressure measurement (1) to (11).
Hereinafter, the pressure measurement materials (1) to (11) will be abbreviated as evaluation samples (1) to (11), respectively.

(1) Gradation of coloring (density difference: ΔD1)
For each of the evaluation samples, the gradation of color development was evaluated based on the difference between the color density when a pressure of 0.05 MPa was applied and the color density when a pressure of 0.04 MPa was applied. The evaluation method and evaluation criteria are as follows.
In the following evaluation criteria, the larger the evaluation rank value, the better the gradation of color development. The evaluation rank that is most excellent in the gradation of color development is "5".
The results are shown in Table 1.

-Evaluation method-
The first sheet and the second sheet of the 2-sheet type pressure measurement materials (1) to (4) and (6) to (10) were cut into a size of 5 cm × 5 cm, respectively, to prepare evaluation samples.
The surface of the color former layer of the first material of the sample for evaluation and the surface of the color developer layer of the second material were superimposed in the contact direction. Two sheets of glass are placed by placing the overlapped first and second materials on a desk by holding the two sheets of glass with a smooth surface, and then placing a weight on the two sheets of glass. A pressure of 0.04 MPa or 0.05 MPa was applied for 120 seconds to color the first and second materials sandwiched by the plates.
After pressing, the first material and the second material are peeled off, and the density of the coloring area formed in the developer layer of the second material is measured using a reflection densitometer RD-19I (manufactured by Gretag Macbeth). did.

The mono-sheet type pressure measurement materials (5) and (11) were cut into a size of 5 cm × 5 cm and used as evaluation samples.
For mono-sheet type pressure measurement materials, place the prepared evaluation sample on a desk by holding it between two glass plates with smooth surfaces, and then place a weight on the two glass plates. A pressure of 0.04 MPa or 0.05 MPa was applied for 120 seconds to color the sheet sandwiched between the two glass plates.
After pressurization, the density of the coloring area formed in the developer layer of the evaluation sample was measured using a reflection densitometer RD-19I (manufactured by Gretag Macbeth).

From the concentration of the coloring area when the color was developed by applying a pressure of 0.05 MPa for each of the evaluation samples for which the concentration of the coloring area was measured as described above, the color forming area when the pressure was applied by 0.04 MPa The concentration was reduced to calculate the concentration difference (ΔD1).

-Evaluation criteria-
5: ΔD1 is 0.20 or more.
4: ΔD1 is not less than 0.15 and less than 0.20.
3: ΔD1 is 0.12 or more and less than 0.15.
2: ΔD1 is 0.10 or more and less than 0.12.
1: ΔD1 is less than 0.10.

(2) Color suppression by rubbing (difference in density: ΔD2)
The color development inhibition by rubbing was evaluated for each of the evaluation samples. The evaluation method and evaluation criteria are as follows. The results are shown in Table 1.

~ 2 sheet type ~
-Evaluation method-
The first sheet and the second sheet of the 2-sheet type pressure measurement materials (1) to (4) and (6) to (10) were cut into a size of 10 cm × 15 cm, respectively, to prepare evaluation samples.
The color former layer of the first material of the sample for evaluation and the color developer layer of the second material are brought into contact with each other and superposed, and the first material is repeatedly moved 20 times with respect to the second material while being superposed. It was rubbed.
After rubbing, the density of the coloring area formed in the developer layer of the sample for evaluation was measured using a reflection densitometer RD-19I (manufactured by Gretag Macbeth).

Mono sheet type
-Evaluation method-
The mono-sheet type pressure measurement materials (5) and (11) were respectively cut into a size of 10 cm × 15 cm, and used as evaluation samples.
For each of the pressure measurement materials (5) and (11), two evaluation samples were prepared. When one of the two evaluation samples is the evaluation sample A and the other is the evaluation sample B, the substrate side of the evaluation sample A and the color former layer side of the evaluation sample B are brought into contact with each other. The sample for evaluation B was repeatedly moved 20 times and scraped against the sample for evaluation A in the state of superposition and superposition.
After rubbing, the density of the coloring area formed in the color former layer of the evaluation sample B was measured using a reflection densitometer RD-19I (manufactured by Gretag Macbeth).

The initial density before rubbing was subtracted from the coloring density after rubbing to calculate the density difference (ΔD2).
It is an acceptable range that ΔD 2 is less than 0.02, preferably not more than 0.01, and more preferably 0.00 (that is, not coloring).

 

 

In Table 1, the description of "-" indicates that the corresponding component is not contained or that the corresponding measurement or evaluation is not performed.

Details of the specific solvents described in Table 1 are summarized below.
・ Synthetic isoparaffin 1 (Idemitsu Kosan Co., Ltd., IP Solvent 1620, synthetic isoparaffin, pour point: <-70 ° C))
・ Synthetic isoparaffin 2 (Idemitsu Kosan Co., Ltd., IP Solvent 2835, pour point: <-60 ° C)
Aromatic oil (a mixture of 1-phenyl-1-xylylethane and 1-phenyl-1-ethylphenylethane, Hysol (registered trademark) SAS 296: specified solvent, Shin Nippon Oil Co., Ltd., pour point: <−47. 5 ° C))

As shown in Table 1, in the pressure measurement material of the example, the difference in color density (ΔD1) can be visually recognized or read in a minute pressure difference (0.01 MPa) between 0.05 MPa and 0.04 MPa. 0.12 or more (evaluation rank 3, 4 or 5), excellent in the gradation of color development at a minute pressure of 0.05 MPa or less, and the color development by abrasion is a difference in density (ΔD 2) Was suppressed to less than 0.02, and it was confirmed that color development by rubbing was also suppressed.
On the other hand, the material for measurement of pressure in Comparative Example 1 containing microcapsules A and microcapsules not containing a specific polar organic compound and not containing microcapsules B suppresses color development due to abrasion, but does not The tonality was inferior in comparison with the pressure measurement materials of the respective examples.
The material for pressure measurement of Comparative Example 2 containing only the microcapsule A and not containing the microcapsule B was inferior to both the gradation of color development and the suppression of color development by rubbing.
The pressure-measuring material of Comparative Example 3 of the mono-sheet type including microcapsules A and microcapsules not containing a specific polar organic compound but not containing microcapsules B suppresses the coloration due to abrasion, but the gradation of coloration The properties were inferior to the pressure measurement materials of the examples.

The disclosure of Japanese Patent Application 2017-129235, filed on June 30, 2017, is incorporated herein by reference in its entirety.
All documents, patent applications, and technical standards described herein are as specific and individually as individual documents, patent applications, and technical standards are incorporated by reference. Incorporated herein by reference.

Claims (7)

A microcapsule A containing an electron donating dye precursor, a solvent having a melting point or a pour point of 30 ° C. or less and a polar organic compound having a melting point exceeding 30 ° C. A microcapsule B not containing an electron donating dye precursor And a material for measuring pressure. The material for pressure measurement according to claim 1, wherein the polar organic compound having a melting point of more than 30 ° C is a compound having an alkyl group having 12 or more carbon atoms and an amide bond. The pressure according to claim 1, wherein the polar organic compound having a melting point of more than 30 ° C is at least one selected from the group consisting of salicylic acid compounds, salts of salicylic acid compounds, phenolic compounds and sulfonamide compounds. Measurement material. The pressure measurement material according to any one of claims 1 to 3, wherein a median diameter D50B of the volume standard of the microcapsule B is larger than a median diameter D50A of the volume standard of the microcapsule A. A first material in which a color former layer containing the microcapsules A is disposed on a first substrate;
A second material in which a developer layer containing an electron accepting compound is disposed on a second substrate;
Equipped with
The material for pressure measurement according to any one of claims 1 to 4, wherein at least one of the first material and the second material contains the microcapsules B. The color developing agent layer of the second material having the same area as the color developing agent layer of the first material is brought into contact with the color developing agent layer of the first material on the color developing agent layer of the first material. 6. The method according to claim 5, wherein a difference between the color density of the first material after 20 times of repetitive motion of the first material with respect to the second material and the concentration before the rubbing is less than 0.02. Material for measuring pressure. The concentration difference obtained by subtracting the concentration after color development by applying pressure under 0.04 MPa is 0.20 or more from the concentration after color development under pressure application at 0.05 MPa. The material for pressure measurement according to any one of the above.