KR20230106691A - Sheet set for pressure measurement, sheet for pressure measurement, microcapsule, dispersion, method for manufacturing sheet set for pressure measurement, method for manufacturing sheet for pressure measurement - Google Patents

Abstract

The present invention provides a pressure measuring sheet set having excellent high temperature suitability, a method for manufacturing a pressure measuring sheet, a microcapsule, a dispersion, a pressure measuring sheet set, and a pressure measuring sheet manufacturing method. A sheet set for pressure measurement according to the present invention includes a first sheet having a first layer containing microcapsules containing a coloring agent and a second sheet having a second layer containing a color developing agent. As the color former, the compound represented by Formula (1) is included, and the thermal decomposition temperature of the capsule wall of the microcapsule is 250°C or higher.

Description

Sheet set for pressure measurement, sheet for pressure measurement, microcapsule, dispersion, method for manufacturing sheet set for pressure measurement, method for manufacturing sheet for pressure measurement

The present invention relates to a sheet set for pressure measurement, a sheet for pressure measurement, a microcapsule, a dispersion, a method for manufacturing a sheet set for pressure measurement, and a method for manufacturing a sheet for pressure measurement.

In recent years, the necessity of measuring the distribution of pressure is increasing due to the high functionality and high precision of products. As a method for measuring the pressure distribution, a pressure measurement sheet set and a pressure measurement sheet (hereinafter, simply referred to as "pressure measurement sheet set, etc.") are generally used from the viewpoint of convenience.

For example, in Patent Literatures 1 to 3, sheet sets for pressure measurement using microcapsules containing a coloring agent and the like are disclosed.

Patent Document 1: International Publication No. 2004/024809 Patent Document 2: International Publication No. 2018/062017 Patent Document 3: International Publication No. 2020/149410

In recent years, even in applications such as high-temperature heat press, heat press, and bonding, it is required to accurately measure the pressure. Conventional pressure measurement sheet sets and the like cannot withstand high-temperature pressurization of 180°C or higher, so the pressure cannot be accurately measured, and measures such as lowering the temperature to less than 150°C are required. However, in a high-temperature environment (especially 180°C or higher), the measurement object such as a mold expands with heat, so the pressure distribution obtained when measuring under a high-temperature environment (especially 180°C or higher) and a low-temperature environment (especially 150°C) The pressure distribution obtained when measured at less than) is strictly different and cannot be accurately measured in many cases.

That is, pressure measurement data at lower temperatures may not reflect the pressure distribution in a high-temperature environment, and a pressure measurement sheet set or the like capable of accurately measuring pressure in a high-temperature environment of 180 ° C. or higher has been demanded.

As a result of measuring the pressure distribution of a conventional pressure measuring sheet set or the like in a high-temperature environment of 180°C or higher, the present inventors found that color development occurred even outside the pressurized area, and the shape of the area that was colored by pressing was easily recognized. was not possible, and it was found that the precise pressure distribution could not be measured. In addition, it was also newly discovered that the color of the color development region differs depending on the pressure time in the case of pressure measurement in a high-temperature environment. If the color of the color development area changes due to a change in the pressurization time despite pressurization at the same pressure, it is impossible to accurately measure the pressure, so improvement has been desired.

Hereinafter, those capable of easily recognizing the shape of a color-developed region by pressing and suppressing color change in the color-developed region due to pressurization time are also referred to as having excellent high-temperature suitability.

In the examples and the like described in Patent Literature 1, a conventional pressure measurement sheet set or the like is used not under a high-temperature environment (especially 180°C or higher) but under 150°C.

As a result of examining the sheet sets for pressure measurement described in Patent Literatures 2 and 3, the inventors of the present invention also found that the high-temperature suitability was poor when used in a high-temperature environment (particularly at 180°C or higher).

In view of the above circumstances, an object of the present invention is to provide a sheet set for pressure measurement with excellent suitability for high temperatures and a sheet for measurement with excellent suitability for high temperatures.

Another object of the present invention is to provide a method for manufacturing a microcapsule, a dispersion, a sheet set for pressure measurement, and a method for manufacturing a sheet for pressure measurement.

MEANS TO SOLVE THE PROBLEM The present inventors discovered that the said subject was solvable by the following structure, as a result of earnestly examining about the said subject.

[1] a first sheet having a first layer containing microcapsules containing a coloring agent;

A sheet set for pressure measurement comprising a second sheet having a second layer containing a color developer, comprising:

The color former contains a compound represented by formula (1) described later,

The sheet set for pressure measurement, wherein the thermal decomposition temperature of the capsule wall of the microcapsule is 250 ° C. or higher.

[2] When the first sheet is heated at 220° C. for 10 minutes, the thermal contraction rate Sa1 in the longitudinal direction of the first sheet and the thermal contraction rate in the width direction orthogonal to the longitudinal direction of the first sheet The sheet set for pressure measurement according to [1], wherein Sa2 is -0.5 to 3.0% in all cases.

[3] The pressure according to [1] or [2], wherein the capsule wall of the microcapsule contains at least one selected from the group consisting of polyurethane urea having a polymethylene polyphenylene structure and melamine resin. A set of measuring sheets.

[4] The sheet set for pressure measurement according to any one of [1] to [3], wherein the capsule walls of the microcapsules contain a resin having structure A or structure B.

Structure A: A structure formed by reacting an aromatic or alicyclic diisocyanate, a compound having three or more active hydrogen groups in one molecule, and polymethylene polyphenyl polyisocyanate.

Structure B: Structure formed by reacting melamine with formaldehyde.

[5] The sheet set for measuring pressure according to any one of [1] to [4], wherein the thickness of the microcapsule wall is 80 to 300 nm.

[6] The sheet set for measuring pressure according to any one of [1] to [5], wherein the content of the compound represented by Formula (1) is 70% by mass or more with respect to the total mass of the color former.

[7] a first layer comprising microcapsules containing a coloring agent;

A sheet for measuring pressure having a second layer containing a developer,

The color former contains a compound represented by formula (1) described later,

The sheet for pressure measurement, wherein the thermal decomposition temperature of the capsule wall of the microcapsule is 250 ° C. or higher.

[8] When the sheet for measuring pressure is heated at 220° C. for 10 minutes, the thermal contraction rate Sb1 in the longitudinal direction of the sheet for measuring pressure and in the width direction orthogonal to the longitudinal direction of the sheet for measuring pressure The sheet for pressure measurement according to [7], wherein the thermal contraction rate Sb2 of each is -0.5 to 3.0%.

[9] The pressure according to [7] or [8], wherein the capsule wall of the microcapsule contains at least one selected from the group consisting of polyurethane urea having a polymethylene polyphenylene structure and melamine resin. sheet for measurement.

[10] The sheet for pressure measurement according to any one of [7] to [9], wherein the capsule wall of the microcapsule contains a resin having structure A or structure B.

Structure A: A structure formed by reacting an aromatic or alicyclic diisocyanate, a compound having three or more active hydrogen groups in one molecule, and polymethylene polyphenyl polyisocyanate.

Structure B: Structure formed by reacting melamine with formaldehyde.

[11] The pressure measurement sheet according to any one of [7] to [10], wherein the thickness of the microcapsule wall is 80 to 300 nm.

[12] The sheet for pressure measurement according to any one of [7] to [11], wherein the content of the compound represented by Formula (1) is 70% by mass or more with respect to the total mass of the color former.

[13] A microcapsule containing a coloring agent,

The color former contains a compound represented by formula (1) described later,

The thermal decomposition temperature of the capsule wall of the microcapsule is 250 ° C. or higher, the microcapsule.

[14] The microcapsule according to [13], wherein the capsule wall of the microcapsule contains at least one selected from the group consisting of polyurethane urea and melamine resin having a polymethylene polyphenylene structure.

[15] The microcapsule according to [13] or [14], wherein a capsule wall of the microcapsule contains a resin having structure A or structure B.

Structure A: A structure formed by reacting an aromatic or alicyclic diisocyanate, a compound having three or more active hydrogen groups in one molecule, and polymethylene polyphenyl polyisocyanate.

Structure B: Structure formed by reacting melamine with formaldehyde.

[16] The microcapsule according to any one of [13] to [15], wherein the thickness of the capsule wall of the microcapsule is 80 to 300 nm.

[17] The microcapsules according to any one of [13] to [16], wherein the content of the compound represented by formula (1) is 70% by mass or more with respect to the total mass of the color former.

[18] A dispersion comprising the microcapsules according to any one of [13] to [17].

[19] The method for producing the sheet set for measuring pressure according to any one of [1] to [6], comprising a step of forming the first layer using the dispersion according to [18].

[20] The method for producing the sheet for pressure measurement according to any one of [7] to [12], comprising a step of forming the first layer using the dispersion liquid according to [18].

According to the present invention, it is possible to provide a sheet set for pressure measurement with excellent suitability for high temperature and a sheet for measurement for pressure with excellent suitability for high temperature.

Further, according to the present invention, it is possible to provide a method for manufacturing a microcapsule, a dispersion, a sheet set for pressure measurement, and a method for manufacturing a sheet for pressure measurement.

1 is a cross-sectional view of one embodiment of a sheet set for pressure measurement.
Fig. 2 is a diagram for explaining a form of use of a sheet set for measuring pressure.
3 is a cross-sectional view of an embodiment of a sheet for measuring pressure.

Hereinafter, the present invention will be described in detail.

In this specification, the numerical range expressed using "-" means the range which includes the numerical value described before and after "-" as a lower limit and an upper limit.

Further, in the numerical ranges described stepwise in this specification, the upper limit or lower limit of a predetermined numerical range may be replaced with the upper limit or lower limit of another stepwisely described numerical range. In addition, in the numerical range described in this specification, you may replace the upper limit value or lower limit value described with a predetermined numerical range with the value shown in the Example.

In this specification, when simply referring to a substituent, examples of the substituent include groups exemplified by the following substituent T.

(substituent T)

As the substituent T, a halogen atom (such as a fluorine atom, a chlorine atom, a bromine atom and an iodine atom), an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, an alkynyl group, an aryl group, a heterocyclic group, a cyano group, A hydroxy group, a nitro group, a carboxy group, an alkoxy group, an aryloxy group, a silyloxy group, a heterocyclic oxy group, an acyloxy group, a carbamoyloxy group, an amino group (including an alkylamino group and an anilino group), an acylamino group, aminocarbonylamino group, alkoxycarbonylamino group, aryloxycarbonylamino group, sulfamoylamino group, alkyl or arylsulfonylamino group, mercapto group, alkylthio group, arylthio group, heterocyclic thio group, sulfamoyl group, sulfo group, An alkyl or arylsulfinyl group, an alkyl or arylsulfonyl group, an acyl group, an aryloxycarbonyl group, an alkoxycarbonyl group, a carbamoyl group, an aryl or heterocyclic azo group, an imide group, a phosphino group, a phosphinyl group, a phosphinyloxy group, and groups containing phosphinylamino groups, silyl groups and polymerizable groups.

Among the above substituents, as for those having a hydrogen atom, the part of the hydrogen atom in the substituent may be further substituted with any one of the above substituents.

Characteristic features of the sheet set for pressure measurement and the sheet for pressure measurement of the present invention are that the color former contains a compound represented by formula (1) (hereinafter also referred to as "specific compound"), and the thermal decomposition temperature of the capsule wall is 250°C or higher. points can be found.

The present inventors have found that, when the color former contains a specific compound and is a capsule wall having a predetermined thermal decomposition temperature, high temperature suitability for a sheet set for pressure measurement or the like is excellent. Specifically, since it contains a specific compound with excellent thermal stability, it is possible to suppress color change in the color development region even when heated for a long time, and by including a capsule wall that is difficult to thermally decompose, it is possible to ), since color development in areas other than the pressurized area is suppressed, the present inventors speculate that the range of the area where color developed by pressing can be easily recognized, and thus the sheet set for pressure measurement is excellent in high-temperature suitability. .

Hereinafter, those that are excellent in high-temperature suitability, such as a sheet set for pressure measurement, are also referred to as having excellent effects of the present invention.

[First Embodiment]

1 is a cross-sectional view of one embodiment of a sheet set for pressure measurement.

The sheet set 10 for measuring pressure includes a first sheet 16 having a first support 12 and a first layer 14 including microcapsules 13 disposed on the first support 12; , a second sheet 22 having a second support 18 and a second layer 20 containing a developer disposed on the second support 18.

When using the sheet set 10 for pressure measurement, as shown in FIG. 2 , the first layer 14 of the first sheet 16 and the second layer 20 of the second sheet 22 face each other, The first sheet 16 and the second sheet 22 are stacked and used. The microcapsules 13 in the pressurized area by pressing from at least one side of the first support body 12 side of the first sheet 16 and the second support body 18 side of the second sheet 22 in the obtained laminate. ) is broken, the color developing agent contained in the microcapsules 13 comes out from the microcapsules 13, and a color development reaction proceeds between the color developing agent in the second layer 20. As a result, color development proceeds in the pressed area.

In addition, as will be described later, the first sheet 16 only needs to have the first layer 14, and may or may not have the first support 12. In addition, the second sheet 22 only needs to have the second layer 20, and may or may not have the second support body 18.

1, the first support 12 and the first layer 14 are directly laminated, but the first support 12 and the first layer 14 are not limited to this aspect and will be described later. ), another layer (for example, adhesive layer) may be arrange|positioned between them. 1, the second support 18 and the second layer 20 are directly laminated, but the second support 18 and the second layer 20 are not limited to this aspect and will be described later. ), another layer (for example, adhesive layer) may be arrange|positioned between them.

Hereinafter, the configuration of the first sheet 16 and the second sheet 22 constituting the sheet set 10 for pressure measurement will be described in detail.

<<First Sheet>>

The first sheet 16 described in FIG. 1 has a first layer 14 including a first support 12 and microcapsules 13 containing a color former.

When the first sheet is heated at 220°C for 10 minutes, both the thermal contraction rate Sa1 in the longitudinal direction of the first sheet and Sa2 in the width direction orthogonal to the longitudinal direction of the first sheet are - It is preferable that it is 0.5-3.0%.

In addition, the method of measuring the thermal contraction rate Sa1 and the thermal contraction rate Sa2 of the first sheet is as shown in the Example column.

The method for setting the thermal contraction rate of the first sheet within the above range is not particularly limited, but as the first support, a film having a thermal shrinkage rate of -0.5 to 3.0 in the longitudinal direction and width direction when heated at 220°C for 10 minutes. It is preferable to apply, and it is more preferable to apply a polyethylene naphthalate film or a polyimide film.

The longitudinal direction of the first sheet means the long direction of the first sheet, and specifically, when the first sheet 16 is rectangular, it means the direction along the long side. Further, the width direction of the first sheet means a direction orthogonal to the longitudinal direction of the first sheet (short longitudinal direction), and means a direction along a short side when the first sheet is rectangular, for example. However, when the first sheet is a square, a direction along any one side constituting the square is referred to as a major axis direction, and a direction along a side orthogonal to the major axis direction is referred to as a width direction.

The first sheet may be sheet (short) or long.

Hereinafter, each member is explained in detail.

[First support]

A 1st support body is a member for supporting a 1st layer. In addition, when the first layer itself can be handled, the first sheet need not have a first support.

The first support may be in any shape of a sheet or plate.

As a 1st support body, a resin film and synthetic paper are mentioned.

Examples of the resin film include polyester films such as polyethylene naphthalate and polyethylene terephthalate films; cellulose derivative films such as cellulose triacetate; polyolefin films such as polypropylene and polyethylene; and polystyrene films.

Examples of the synthetic paper include, for example, synthetic paper obtained by biaxially stretching polypropylene or polyethylene terephthalate to form a large number of microvoids (e.g., Yupo), synthetic fibers such as polyethylene, polypropylene, polyethylene terephthalate, and polyamide. synthetic paper produced using and synthetic paper laminated on a part, one side or both sides of paper.

Especially, as a 1st support body, a resin film or synthetic paper is preferable, a resin film is more preferable, a polyester film is still more preferable, and a polyethylene naphthalate film is especially preferable.

As a commercial item of a polyethylene naphthalate film, Theonex (registered trademark) Q51, Q53, Q81, and Q83 (made by Teijin Film Solutions) are mentioned, for example.

The first support is preferably transparent from the viewpoint that the color developing property can be visually recognized even when viewed from the side of the support.

As for the thickness of a 1st support body, 10-200 micrometers are preferable.

[First layer]

The first layer includes microcapsules containing a specific compound and having a capsule wall at a predetermined thermal decomposition temperature.

Hereinafter, first, the material constituting the microcapsule will be described in detail.

<Microcapsule>

The microcapsule has a core portion and a capsule wall for enclosing a core material constituting the core portion (enclosed material (hereinafter also referred to as "encapsulated component")).

In the present invention, the microcapsule contains a color former containing a specific compound as a core material (encapsulation component). Generally, since the color coupler is enclosed in the microcapsules, the color coupler may exist in the microcapsules until the microcapsules are destroyed by pressing.

The microcapsule has a capsule wall containing a core material.

The thermal decomposition temperature of the capsule wall of the microcapsule is 250°C or higher, preferably higher than 250°C, more preferably higher than 255°C, and still more preferably higher than 260°C. The upper limit is not particularly limited, but is often 500°C or less.

A method for measuring the thermal decomposition temperature of the capsule wall is as follows.

50 first layers (microcapsule layers) 1 cm long x 1 cm wide are prepared, all are immersed in 10 mL of water, and left to stand for 24 hours to obtain an aqueous dispersion of microcapsules. In addition, when the first sheet includes the first support, 50 sheets of 1 cm long x 1 cm wide may be prepared and immersed in the first sheet.

The obtained aqueous dispersion of microcapsules is centrifuged at 15000 rpm for 30 minutes to fractionate microcapsules. To the fractionated microcapsules, 1000 times more ethyl acetate was added, and further stirred at 25°C for 24 hours. Thereafter, the obtained solution is filtered, and the resulting residue is vacuum-dried at 60°C for 48 hours to obtain microcapsules (hereinafter simply referred to as "measurement materials") with nothing contained therein. That is, the material for the capsule wall of the microcapsule, which is the subject of measurement of the thermal decomposition temperature, is obtained.

Next, the thermal decomposition temperature of the obtained measurement material is measured using a thermogravimetric differential thermal analysis apparatus TG-DTA (device name: DTG-60, manufactured by Shimadzu Corporation). In addition, the thermal decomposition temperature is obtained by raising the temperature of the measurement material from room temperature at a constant heating rate (10 ° C./min) in the thermogravimetric analysis (TGA) of the air atmosphere and reducing the mass by 5 mass% with respect to the mass of the measurement material before heating. Let the temperature at the time be the thermal decomposition temperature (°C).

Examples of the material (wall material) for the capsule wall of the microcapsule include known resins conventionally used as wall materials for microcapsules containing color formers for use in pressure-sensitive copying paper and thermal recording paper.

It is preferable that the capsule wall of the microcapsule is substantially composed of resin.

Being substantially composed of resin means that the content of the resin is 90% by mass or more with respect to the total mass of the capsule wall of the microcapsule, and 100% by mass is preferable. That is, the capsule wall of the microcapsule is preferably made of resin.

Examples of the resin include polyurethane, polyurea, polyurethane urea, melamine resin, acrylic resin, and gelatin.

Among them, from the viewpoint of more excellent effects of the present invention, the capsule wall of the microcapsule preferably contains at least one selected from the group consisting of polyurethane, polyurea, polyurethane urea, and melamine resin. , It is more preferable to include at least one selected from the group consisting of polyurethane urea and melamine resin, and it is more preferable to include polyurethane urea or melamine resin having a polymethylene polyphenylene structure.

In addition, a polymethylene polyphenylene structure means the structure represented by Formula (Y). In Formula (Y), n represents an integer greater than or equal to 1, and n has a preferable integer of 1 to 10, more preferably an integer of 1 to 5.

[Formula 1]

It is preferable that a melamine resin is a reaction product formed by polycondensation of melamine and formaldehyde.

Polyisocyanate is a compound having two or more isocyanate groups.

Examples of polyisocyanates include aromatic polyisocyanates and aliphatic polyisocyanates, and aromatic polyisocyanates can introduce aromatic ring groups into the capsule walls of microcapsules. Nate is preferred.

Examples of the aromatic polyisocyanate include aromatic diisocyanate, and examples thereof include m-phenylenediisocyanate, p-phenylenediisocyanate, and 2,6-tolylenedia. Isocyanate, 2,4-tolylene diisocyanate, naphthalene-1,4-diisocyanate, diphenylmethane-4,4'-diisocyanate, 3,3'- Dimethoxy-biphenyl diisocyanate, 3,3'-dimethyldiphenylmethane-4,4'-diisocyanate, xylylene-1,4-diisocyanate, xylylene -1,3-diisocyanate, 4-chloroxylylene-1,3-diisocyanate, 2-methylxylylene-1,3-diisocyanate, 4,4'-diphenyl propane diisocyanate and 4,4'-diphenylhexafluoropropane diisocyanate.

Examples of the aliphatic polyisocyanate include aliphatic diisocyanates, and examples thereof include trimethylene diisocyanate, hexamethylene diisocyanate, and propylene-1,2-diisocyanate. , butylene-1,2-diisocyanate, cyclohexylene-1,2-diisocyanate, cyclohexylene-1,3-diisocyanate, cyclohexylene-1,4- Diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, 1,4-bis(isocyanatemethyl)cyclohexane, 1,3-bis(isocyanatemethyl ) cyclohexane, isophorone diisocyanate, lysine diisocyanate and hydrogenated xylylene diisocyanate.

As polyisocyanate, trifunctional or more than trifunctional polyisocyanate (for example, trifunctional triisocyanate and tetrafunctional tetraisocyanate) is also mentioned.

Specifically, as the polyisocyanate, a biuret body that is a trimer of the above-mentioned bifunctional polyisocyanate, an isocyanurate body, a polyol such as trimethylolpropane, and a bifunctional polyisocyanate polyisocyanates and lysine triisocyanates having polymerizable groups such as adducts (adducts) of nates, formalin condensates of benzene isocyanates, and methacryloyloxyethyl isocyanates; can be heard

Regarding polyisocyanate, "Polyurethane Resin Handbook" (edited by Keiji Iwata, published by Nikkan Kogyo Shinbunsha (1987)) can be cited.

Especially, as one of the suitable aspects of polyisocyanate, a trifunctional or higher functional polyisocyanate is preferable.

As a trifunctional or more than trifunctional polyisocyanate, a trifunctional or more than trifunctional aromatic polyisocyanate and a trifunctional or more than trifunctional aliphatic polyisocyanate are mentioned, for example.

As the trifunctional or higher functional polyisocyanate, an aromatic or alicyclic diisocyanate and a compound having three or more active hydrogen groups in one molecule (for example, a trifunctional or higher functional polyol, polyamine or polythiol, etc.) Tri- or higher-functional polyisocyanate (adduct-type tri- or higher-functional polyisocyanate), which is an adduct (adduct) of , and a trimer of aromatic or alicyclic diisocyanate (biuret-type or isocyanurate). rate type) is also preferable, and trifunctional or higher functional polyisocyanate as the adduct (adduct) is more preferable.

As the above-mentioned trifunctional or higher functional polyisocyanate, an aromatic or alicyclic diisocyanate and a trifunctional or higher functional polyisocyanate, which is an adduct of a polyol having three or more hydroxyl groups in one molecule, is preferable. , A trifunctional polyisocyanate that is an adduct of an aromatic or alicyclic diisocyanate and a polyol having three hydroxyl groups in one molecule is more preferable.

As the adduct, it is preferable to use an adduct obtained by using aromatic diisocyanate from the viewpoint of more excellent effects of the present invention.

As said polyol, the trifunctional or higher molecular weight polyol mentioned later is preferable, for example, and trimethylol propane is more preferable.

Examples of adduct-type trifunctional or higher than trifunctional polyisocyanates include Takenate (registered trademark) D-102, D-103, D-103H, D-103M2, P49-75S, D-110N, D-120N , D-140N, D-160N (Mitsui Chemical Co., Ltd.), Death Module (registered trademark) L75, UL57SP (Sumika Bayer Urethane Co., Ltd.), Coronate (registered trademark) HL, HX, L (Nippon Polyurethane Co., Ltd.) ), P301-75E (manufactured by Asahi Kasei Co., Ltd.) and Burnock (registered trademark) D-750 (manufactured by DIC Corporation).

Among them, as the adduct-type trifunctional or higher functional polyisocyanate, Takenate (registered trademark) D-110N, D-120N, D-140N, D-160N (manufactured by Mitsui Chemicals Co., Ltd.) or Burnock (registered trademark) manufactured by DIC Co., Ltd. Trademark) D-750 is preferred, and Burnnock (registered trademark) D-750 manufactured by DIC Corporation is more preferred.

Examples of isocyanurate-type trifunctional or higher functional polyisocyanates include Takenate (registered trademark) D-127N, D-170N, D-170HN, D-172N, D-177N, D-204 ( Mitsui Chemical Co., Ltd.), Smidul N3300, Death Module (registered trademark) N3600, N3900, Z4470BA (Sumika Bayer Urethane), Coronate (registered trademark) HX, HK (Nippon Polyurethane Co., Ltd.), Duranate ( registered trademark) TPA-100, TKA-100, TSA-100, TSS-100, TLA-100 and TSE-100 (manufactured by Asahi Kasei Co., Ltd.).

As biuret-type trifunctional or higher functional polyisocyanates, for example, Takenate (registered trademark) D-165N, NP1100 (manufactured by Mitsui Chemicals Co., Ltd.), Death Module (registered trademark) N3200 (Sumika Bayer Urethane), and Duranate (registered trademark) 24A-100 (manufactured by Asahi Kasei Co., Ltd.) is exemplified.

Moreover, as polyisocyanate, polymethylene polyphenyl polyisocyanate is also preferable. As polymethylene polyphenyl polyisocyanate, the compound represented by Formula (X) is preferable.

[Formula 2]

In formula (X), n represents an integer greater than or equal to 1.

As n, an integer of 1 to 10 is preferable, and an integer of 1 to 5 is more preferable at the point where the measurement of the pressure distribution under high temperature can be more satisfactorily performed.

As polyisocyanate containing polymethylene polyphenyl polyisocyanate, for example, milionate MR-100, milionate MR-200, milionate MR-400 (manufactured by Tosoh Corporation), WANNATE PM -200, WANNATE PM-400 (manufactured by Wanhwa Japan Co., Ltd.), Cosmonate M-50, Cosmonate M-100, Cosmonate M-200, Cosmonate M-300 (manufactured by Mitsui Chemicals Co., Ltd.), and Boranate M-595 (made by the Dow Chemical Company) is mentioned.

A polyol is a compound which has two or more hydroxyl groups.

Examples of the polyol include low molecular weight polyols (e.g., aliphatic polyols and aromatic polyols), polyvinyl alcohol, polyether polyols, polyester polyols, polylactone polyols, castor oil polyols, polyolefin polyols, and hydroxyls. Time-containing amine-type compounds are exemplified.

Further, the low molecular weight polyol means a polyol having a molecular weight of 400 or less, and examples thereof include bifunctional low molecular weight polyols such as ethylene glycol, diethylene glycol and propylene glycol; and trifunctional or higher molecular weight polyols such as glycerin, trimethylolpropane, hexanetriol, pentaerythritol and sorbitol.

Examples of the hydroxy group-containing amine compound include oxyalkylated derivatives of amino compounds, and amino alcohols are preferred.

Examples of amino alcohols include propylene oxide and ethylene oxide adducts of amino compounds such as ethylenediamine. Specifically, N,N,N',N'-tetrakis[2-hydroxypropyl ]ethylenediamine and N,N,N',N'-tetrakis[2-hydroxyethyl]ethylenediamine.

A polyamine is a compound having two or more amino groups (primary amino groups or secondary amino groups).

Examples of the polyamine include aliphatic polyvalent amines such as diethylenetriamine, triethylenetetramine, 1,3-propylenediamine and hexamethylenediamine; epoxy compound adducts of aliphatic polyhydric amines; alicyclic polyhydric amines such as piperazine; and heterocyclic diamines such as 3,9-bis-aminopropyl-2,4,8,10-tetraoxaspiro-(5,5)undecane.

As a preferable aspect of the resin contained in the capsule wall of the microcapsule, those having the structure A or the structure B are exemplified. Structure A or Structure B can improve the rigidity while maintaining a high crosslinking density, so that migration of the encapsulated color former can be further suppressed, so that the effect of the present invention can be further improved.

Structure A is an aromatic or alicyclic diisocyanate, a compound having three or more active hydrogen groups in one molecule, and polymethylene polyphenyl polyisocyanate (preferably, a compound represented by formula (X)) It is a structure formed by reacting

Structure B is a structure formed by reacting melamine with formaldehyde.

In addition, as another suitable embodiment of the resin contained in the capsule wall of the microcapsule, an aromatic or alicyclic diisocyanate and a trifunctional or higher functional polyisocyanate that is an adduct of a compound having three or more active hydrogen groups in one molecule. nate A (hereinafter also simply referred to as “polyisocyanate A”), and polyisocyanate B selected from the group consisting of aromatic diisocyanates and polymethylenepolyphenylpolyisocyanates ( Hereinafter, it is also simply referred to as “polyisocyanate B”).

That is, the capsule wall of the microcapsule preferably contains a resin formed using the polyisocyanate A and the polyisocyanate B in view of the excellent effect of the present invention.

As polyisocyanate B, aromatic diisocyanate may be used independently, polymethylene polyphenyl polyisocyanate may be used independently, or both may be mixed and used.

Among them, as polyisocyanate B, a mixture of aromatic diisocyanate and polymethylene polyphenyl polyisocyanate is preferable.

In the above mixture, the mass ratio of the mass of polymethylene polyphenyl polyisocyanate to the mass of aromatic diisocyanate (mass of polymethylene polyphenyl polyisocyanate/mass of aromatic diisocyanate) ) is preferably 0.1 to 10, more preferably 0.5 to 2, still more preferably 0.75 to 1.5.

As for the viscosity of polyisocyanate B, 100-1000 mPa*s are preferable.

In addition, the said viscosity is a viscosity in 25 degreeC.

When polyisocyanate A and polyisocyanate B are used together, the mass ratio of the mass of the polyisocyanate A to the mass of the polyisocyanate B in view of the excellent effect of the present invention ( Mass of polyisocyanate A/mass of polyisocyanate B) is preferably 20/80 to 98/2, more preferably 20/80 to 90/10, and 20/80 to 70/30 this is more preferable

The volume-based median diameter (D50) of the microcapsule is preferably 1 to 80 μm, more preferably 5 to 70 μm, and still more preferably 10 to 50 μm.

The volume-based median diameter of the microcapsules can be controlled by adjusting the microcapsule manufacturing conditions and the like.

Here, the volume-based median diameter of the microcapsule is the diameter at which the sum of the volumes of the particles on the large diameter side and the small diameter side is equal when the total volume of the entire microcapsule is divided into two as a threshold value of 50%. says That is, the median diameter corresponds to what is called D50.

It is a value calculated by photographing the surface of the first layer of the first sheet having the first layer containing microcapsules at 1000 times with an optical microscope and measuring the size of all microcapsules in the range of 500 μm × 500 μm.

Also, the volume-based median diameter of the microcapsules contained in the dispersion may be measured by a laser diffraction/scattering type particle size distribution analyzer (LA-960/manufactured by HORIBA).

The thickness of the capsule wall (number average wall thickness) of the microcapsule is often 0.01 to 2.0 μm, preferably 0.05 to 1.0 μm, more preferably 50 to 500 nm, and the effect of the present invention is more excellent. 80 to 300 nm is more preferable, and 80 to 250 nm is particularly preferable, and 100 to 200 nm is most preferable in view of superior gradation at high temperatures.

The thickness of the microcapsule refers to the thickness of the capsule wall forming the capsule particles of the microcapsule, and the number average wall thickness refers to the average thickness of the individual capsule walls of 5 microcapsules obtained by a scanning electron microscope (SEM). refers to an average value More specifically, a cross-sectional slice of the first sheet having a first layer containing microcapsules was prepared, and the cross-section was observed at 200 times by SEM, [(median diameter (D50) based on the volume of the microcapsules value) × 0.9] to [(value of the median diameter (D50) based on the volume of the microcapsule) × 1.1] After selecting 5 random microcapsules having a long diameter, the cross section of each selected microcapsule is 15000 Observe twice to obtain the thickness of the capsule wall of the microcapsule, and calculate the average value. In addition, the longest diameter means the longest diameter when microcapsules are observed.

The ratio (δ/Dm) of the number average wall thickness δ of the microcapsule to the volume-based median diameter (D50) Dm of the microcapsule (δ/Dm) is not particularly limited, but is often 0.001 or more.

Among them, it is preferable to satisfy the relationship of formula (1) at a point where the effects of the present invention are more excellent.

Equation (1) 0.100>δ/Dm>0.001

That is, the ratio (δ/Dm) is preferably greater than 0.001 and less than 0.100. If the relationship of Equation (1) is satisfied, the color development density gradation can be set within a range that is easy to recognize depending on the pressure.

Microcapsules may be used individually by 1 type, or may use 2 or more types together.

The content of the microcapsules in the first layer is preferably 50 to 90% by mass, and more preferably 55 to 80% by mass with respect to the total mass of the first layer.

(color former)

The microcapsule contains a color former containing a compound represented by formula (1).

A color developing agent is a compound that develops color from a colorless state by being in contact with a developing agent described later. As the color former, an electron-donating pigment precursor (color-developing pigment precursor) is preferable. That is, as a color former, an electron-donating colorless dye is preferable.

((Compound represented by Formula (1)))

[Formula 3]

In Formula (1), R ¹ represents an alkyl group which may have a substituent. R ³ represents -NR ^A R ^B . R ^A and R ^B each independently represent an alkyl group which may have a substituent or an aryl group which may have a substituent. R ² and R ⁴ each independently represent a halogen atom. Q represents a benzene ring or a naphthalene ring. X represents -O- or -NR ⁵ -. R ⁵ represents an alkyl group which may have a substituent or an aryl group which may have a substituent. p and q represent the integer of 0-4 each independently. r represents the integer of 1-3. s represents an integer of 0 to 3. However, p+q is an integer of 0 to 4, and r+s is an integer of 1 to 4.

R ¹ represents an alkyl group which may have a substituent.

The alkyl group may be linear, branched or cyclic, preferably linear or branched.

1-10 are preferable and, as for carbon number of the said alkyl group, 1-5 are more preferable.

As a substituent which the said alkyl group may have, the group illustrated by the substituent T mentioned above is mentioned.

A plurality of R ¹ 's may be the same or different.

R ³ represents -NR ^A R ^B .

R ^A and R ^B each independently represent an alkyl group which may have a substituent or an aryl group which may have a substituent.

The alkyl group may be linear, branched or cyclic, preferably linear or branched.

1-10 are preferable and, as for carbon number of the said alkyl group, 1-5 are more preferable.

6-20 are preferable and, as for carbon number of the said aryl group, 6-10 are more preferable.

The aryl group may be either monocyclic or polycyclic.

As a substituent which the said alkyl group and the said aryl group may have, the group illustrated by the substituent T mentioned above is mentioned.

Especially, it is preferable that at least one of R ^A and R ^B represents an alkyl group which may have a substituent, and it is more preferable that it represents an unsubstituted alkyl group.

A plurality of R ³ 's may be the same or different.

R ² and R ⁴ each independently represent a halogen atom.

As said halogen atom, a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom are mentioned, for example, A chlorine atom or a bromine atom is preferable, and a bromine atom is more preferable.

X represents -O- or -NR ⁵ -.

Especially, as X, -O- is preferable.

R ⁵ represents an alkyl group which may have a substituent or an aryl group which may have a substituent.

The alkyl group may be linear, branched or cyclic, preferably linear or branched.

1-10 are preferable and, as for carbon number of the said alkyl group, 1-5 are more preferable.

6-20 are preferable and, as for carbon number of the said aryl group, 6-10 are more preferable.

The aryl group may be either monocyclic or polycyclic.

Among them, as R ⁵ , an alkyl group which may have a substituent or an aryl group which may have a substituent is preferable, and an aryl group which may have a substituent is more preferable.

Examples of the substituents that the alkyl group and the aryl group may have include groups exemplified by the substituent T described above, preferably at least one selected from the group consisting of a halogen atom, a cyano group, a nitro group, and a carboxy group, and Logi is more preferred.

p and q represent the integer of 0-4 each independently. r represents the integer of 1-3. s represents an integer of 0 to 3. However, p+q is an integer of 0 to 4, and r+s is an integer of 1 to 4.

As p, an integer of 0 to 2 is preferable. As q, an integer of 0 to 1 is preferable. As r, an integer of 1 to 2 is preferable, and 1 is more preferable. As s, the integer of 0-1 is preferable and 0 is more preferable.

Moreover, when Q represents a naphthalene ring, 0 is preferable as p and q.

As p+q, an integer of 0 to 3 is preferable, and an integer of 0 to 2 is more preferable.

As r+s, an integer of 1 to 3 is preferable, an integer of 1 to 2 is more preferable, and 1 is still more preferable.

((Compound represented by Formula (2)))

As a compound represented by Formula (1), the compound represented by Formula (2) is preferable.

[Formula 4]

In Formula (2), R ⁶ represents an alkyl group which may have a substituent. R ⁷ represents a halogen atom. R ^A and R ^B each independently represent an alkyl group which may have a substituent or an aryl group which may have a substituent. Q represents a benzene ring or a naphthalene ring. t and u each independently represent an integer of 0 to 4. However, t+u is an integer from 0 to 4.

R ⁶ represents an alkyl group which may have a substituent.

As said alkyl group, it has the same meaning as R ^<1> in Formula (1), and the suitable range is also the same.

R ⁷ represents a halogen atom.

R ⁷ has the same meaning as R ² in Formula (1), and the suitable range is also the same.

R ^A and R ^B each independently represent an alkyl group which may have a substituent or an aryl group which may have a substituent. Q represents a benzene ring or a naphthalene ring.

R ^A , R ^B and Q in Formula (2) have the same meaning as R ^A , R ^B and Q in Formula (1) described above, respectively, and the suitable ranges are also the same.

t and u each independently represent an integer of 0 to 4. However, t+u is an integer from 0 to 4.

As t, an integer of 0 to 2 is preferable. As u, an integer of 0 to 1 is preferable.

Moreover, when Q represents a naphthalene ring, 0 is preferable as t and u.

As t+u, an integer of 0 to 3 is preferable, and an integer of 0 to 2 is more preferable.

As a specific compound, the following compounds are mentioned.

[Formula 5]

The microcapsule may contain other coloring agents in addition to the specific compound.

Other color formers are not particularly limited as long as they are color formers other than specific compounds, but include known color formers for use in pressure-sensitive copy paper or thermal recording paper.

As another color former, the compound represented by Formula (D) is preferable from the point which is excellent in visibility.

[Formula 6]

In formula (D), R ^D1 and R ^D3 each independently represent a hydrogen atom, an alkyl group which may have a substituent, or an aryl group which may have a substituent.

1-10 are preferable and, as for carbon number of the alkyl group represented by R ^D1 and R ^D3 , 1-5 are more preferable.

6-20 are preferable and, as for carbon number of the said aryl group, 6-10 are more preferable.

Examples of the substituent that the alkyl group and the aryl group may have include groups exemplified by the substituent T described above, and examples of R ^D1 and R ^D3 are each independently an alkyl group which may have a substituent, or an aryl which may have a substituent. A group is preferable, an alkyl group which may have a substituent is more preferable, and an unsubstituted alkyl group is still more preferable.

R ^D2 and R ^D4 each independently represent an alkyl group which may have a substituent or an aryl group which may have a substituent.

1-10 are preferable and, as for carbon number of the alkyl group represented by R ^D2 and R ^D4 , 1-5 are more preferable.

The aryl groups represented by R ^D2 and R ^D4 may be either monocyclic or polycyclic.

6-20 are preferable and, as for carbon number of the said aryl group, 6-10 are more preferable.

As a substituent which the said alkyl group and the said aryl group may have, the group illustrated by the substituent T mentioned above is mentioned.

Among them, as R ^D2 and R ^D4 , each independently an alkyl group which may have a substituent is preferable, and an unsubstituted alkyl group is more preferable.

Among them, it is preferable that all of R ^D1 to R ^D4 are unsubstituted alkyl groups, and it is more preferable that they are the same unsubstituted alkyl groups.

R ^D5 represents -O- or -NR ^D6 -.

Among them, -NR ^D6 - is preferable.

R ^D6 represents an alkyl group which may have a substituent or an aryl group which may have a substituent.

1-10 are preferable and, as for carbon number of the alkyl group represented by R ^D6 , 1-5 are more preferable.

6-20 are preferable and, as for carbon number of the said aryl group, 6-10 are more preferable.

The aryl group represented by R ^D6 may have a monocyclic structure or a bicyclic structure.

As a substituent which the said alkyl group and the said aryl group may have, the group illustrated by the substituent T mentioned above is mentioned.

Among them, R ^D6 is preferably an aryl group which may have a substituent, more preferably an aryl group substituted with a group selected from the group consisting of a halogen atom, a cyano group, a nitro group, and a carboxyl group, and substituted with a nitro group. aryl groups are more preferred.

The molecular weight of the compound represented by the formula (D) is not particularly limited, but is preferably 300 or more and more preferably 500 or more. The upper limit is not particularly limited, but is preferably 2000 or less, and more preferably 1000 or less.

Examples of other color formers include triphenylmethanephthalide-based compounds, fluoran-based compounds, phenothiazine-based compounds, indolylphthalide-based compounds, azaindolylphthalide-based compounds, leucooramine-based compounds, rhodamine lactam-based compounds, triphenylmethane-based compounds, diphenylmethane-based compounds, triazene-based compounds, spiropyran-based compounds, and fluorene-based compounds.

As other coloring agents, for example, 3-(4-diethylamino-2-ethoxyphenyl)-3-(1-ethyl-2-methylindol-3-yl)-4-azaphthalide, 3- (4-diethylamino-2-ethoxyphenyl)-3-(1-n-octyl-2-methylindol-3-yl)phthalide, 3-[2,2-bis(1-ethyl-2- Methylindol-3-yl) vinyl] -3- (4-diethylaminophenyl) -phthalide, 2-anilino-6-dibutylamino-3-methylfluoran, 6-diethylamino-3-methyl -2-(2,6-xylidino)-fluoran, 2-(2-chloroanilino)-6-dibutylaminofluoran, 3,3-bis(4-dimethylaminophenyl)-6-di Methylaminophthalide, 2-anilino-6-diethylamino-3-methylfluoran and 3',6'-bis(diethylamino)-2-(4-nitrophenyl)spiro[isoindole- 1,9'-xanthene] -3-one. For details of the above compounds, the description of Unexamined-Japanese-Patent No. 5-257272 can be referred.

The molecular weight of the coloring agent is 300 or more in many cases. The upper limit is often 1000 or less, and 600 or less is preferable from the viewpoint of more excellent effects of the present invention.

You may use a coloring agent individually by 1 type or in mixture of 2 or more types.

The content of the coloring agent in the first layer is preferably 0.1 to 10 g/m ² and more preferably 0.1 to 4 g/m ² .

The content of the specific compound is preferably 10% by mass or more, more preferably 30% by mass or more, and still more preferably 50% by mass or more, based on the total mass of the coloring agent, and is 70% by mass from the viewpoint of excellent light resistance after color development. The above is particularly preferred. As for an upper limit, 100 mass % or less is preferable with respect to the total mass of a coloring agent.

(other ingredients)

The microcapsules may contain other components in addition to the color former described above.

Examples of the other components include solvents and additives such as ultraviolet absorbers, light stabilizers, antioxidants, waxes, and odor suppressants, and solvents are preferred.

As the ultraviolet absorber, a compound having a benzotriazole structure is preferable.

It is preferable that a solvent contains an aromatic solvent from a viewpoint of improving the solubility of a color former.

Examples of the solvent include alkylnaphthalene-based compounds such as diisopropylnaphthalene, diarylalkane-based compounds such as 1-phenyl-1-xylylethane, alkylbiphenyl-based compounds such as isopropylbiphenyl, and triarylmethane. aromatic hydrocarbons such as phosphorus-based compounds, alkylbenzene-based compounds, benzylnaphthalene-based compounds, diarylalkylene-based compounds, and arylindein-based compounds; aliphatic hydrocarbons such as dibutyl phthalate and isoparaffin; and natural animal and vegetable oils such as soybean oil, corn oil, cottonseed oil, rapeseed oil, olive oil, palm oil, castor oil and fish oil, and natural high boiling point oils such as mineral oil.

You may use a solvent individually by 1 type or in mixture of 2 or more types.

When the solvent is contained in the microcapsules, the mass ratio of the mass of the color former to the mass of the solvent (mass of the solvent/mass of the color former) is preferably 98/2 to 30/70, and 97/3 in terms of color development. ~40/60 is more preferred.

<Method for manufacturing microcapsules>

The method for producing the microcapsules containing the color former is not particularly limited, and examples thereof include known methods such as interfacial polymerization, internal polymerization, phase separation, external polymerization, and coacervation, and interfacial polymerization law is preferred

As the interfacial polymerization method, a raw material containing a color former, a capsule wall material (for example, polyisocyanate, and at least one selected from the group consisting of polyols and polyamines. Further, polyisocyanate and water are reacted). process to prepare an emulsion by dispersing an oil phase containing an emulsifier in an aqueous phase containing an emulsifier (emulsification process ), and a step of polymerizing the capsule wall material at the interface between the oil phase and the water phase to form a capsule wall and forming microcapsules containing a coloring agent (encapsulation step) is preferable.

The mass ratio of the total amount of polyol and polyamine to the amount of polyisocyanate (total amount of polyol and polyamine/amount of polyisocyanate) in the above raw materials is not particularly limited, but is 0.1/99.9 to 30 /70 is preferable, and 1/99 - 25/75 are more preferable.

As described above, as the polyisocyanate, the polyisocyanate A and the polyisocyanate B may be used in combination. When using both together, the suitable range of the mixing ratio of both is as above-mentioned.

In addition, the type of emulsifier used in the emulsification step is not particularly limited, but examples thereof include a dispersant and a surfactant.

As a dispersing agent, polyvinyl alcohol is mentioned, for example.

The first layer may contain other components in addition to the microcapsules described above.

Examples of other components include polymeric binders, inorganic fillers (eg, colloidal silica), optical whitening agents, antifoaming agents, penetrants, ultraviolet absorbers, surfactants, and preservatives.

As the polymeric binder, for example, a styrene-butadiene copolymer, polyvinyl acetate, polyacrylic acid ester, polyvinyl alcohol, polyacrylic acid, maleic anhydride-styrene copolymer, starch, casein, gum arabic, gelatin, Synthetic polymers and natural polymers, such as carboxymethyl cellulose or its salt, and methyl cellulose, are mentioned.

The content of the polymeric binder is not particularly limited, but is preferably 0 to 50% by mass relative to the total mass of the first layer. 0.1-20 mass % is preferable and 0.2-10 mass % is more preferable at the point suitable for the low-pressure area|region of 20 MPa or less.

Examples of the surfactant include anionic surfactants, nonionic surfactants, cationic surfactants, and the like, and from the viewpoint of maintaining the dispersibility of the microcapsules, anionic surfactants or nonionic surfactants is preferable

Moreover, as surfactant, a fluorochemical surfactant, silicone type surfactant, hydrocarbon type surfactant, etc. are mentioned, and a hydrocarbon type surfactant is preferable at the point which maintains coating property and the dispersibility of microcapsules.

The content of the surfactant is not particularly limited, but is preferably 0.01 to 10% by mass, and more preferably 0.1 to 5% by mass, based on the total mass of the first layer.

The inorganic filler is preferably introduced to facilitate separation of the first sheet and the second sheet after overlapping the first sheet and the second sheet and measuring the heating pressure.

Silica particles or alumina particles are preferable as the inorganic filler from the viewpoint of making it easy to separate the first sheet and the second sheet.

The median diameter of the inorganic filler is preferably 0.001 to 1 μm, more preferably 0.005 to 0.1 μm, and still more preferably 0.005 to 0.05 μm.

The content of the inorganic filler is preferably 1 to 50% by mass, preferably 3 to 30% by mass, and more preferably 5 to 20% by mass with respect to the total mass of the first layer.

The thickness of the first layer is not particularly limited, but is preferably 0.01 to 5 μm, and preferably 0.02 to 3 μm. Here, the thickness of the first layer means a thickness excluding microcapsules exposed from the surface of the layer when the average particle diameter of the microcapsules is greater than the layer thickness. When the thickness of the first layer is within the above range, when the composition for forming the first layer containing microcapsules is applied and then dried, aggregation of the microcapsules can be suppressed, and the capsules can be controlled to be broken with a desired pressure. . The thickness of the first layer is preferably 50% or less, and preferably 25% or less of the average particle diameter of the microcapsules. Since the microcapsule is more fragile as the thickness of the first layer is smaller than that of the microcapsule, it can be adjusted according to the pressure band to be measured.

In addition, the unit area mass (g/m ² ) of the first layer is not particularly limited, but is preferably 0.5 to 20 g/m ² .

[Method of Forming First Layer]

A method of forming the first layer is not particularly limited, but a known method may be used.

For example, a method in which a composition for forming the first layer containing microcapsules is applied onto the first support and, if necessary, dried.

The composition for forming the first layer may be a dispersion in which microcapsules are dispersed in water or the like.

A dispersion in which microcapsules are dispersed can be prepared by mechanically dispersing the microcapsules in water or the like.

The composition for forming the first layer preferably contains at least microcapsules and a solvent. Further, the microcapsule dispersion obtained by the interfacial polymerization method described above may be used as the composition for forming the first layer.

The composition for forming the first layer may contain other components that may be contained in the first layer described above.

The method of applying the composition for forming the first layer is not particularly limited, but examples of the coating machine used at the time of application include an air knife coater, a rod coater, a bar coater, a curtain coater, a gravure coater, an extrusion coater, die coaters, slide bead coaters and blade coaters.

After applying the composition for forming the first layer onto the first support, a drying treatment may be performed on the coating film, if necessary. A heat treatment is mentioned as a drying process.

In the above, although the method of forming the 1st layer on the 1st support body was demonstrated, it is not limited to the said aspect. For example, after forming a 1st layer on a temporary support body, you may peel off a temporary support body and may form the 1st sheet|seat consisting of a 1st layer.

The temporary support is not particularly limited as long as it is a peelable support.

<Other members>

The first sheet may have other members in addition to the members described above.

The first sheet may have, for example, an adhesive layer between the first support body and the first layer to enhance the adhesion between the two.

Although it does not restrict|limit especially as an adhesive layer, It is preferable that it is a layer which has resin.

The thickness of the adhesive layer is preferably 0.005 to 5 μm, and more preferably 0.01 to 1 μm.

<<Second sheet>>

The second sheet 22 shown in FIG. 1 has a second support 18 and a second layer 20 containing a color developer disposed on the second support 18 .

The suitable ranges of thermal contraction rate Sc1 and thermal contraction rate Sc2 in the second sheet are the same as thermal contraction rate Sa1 and thermal contraction rate Sa2 in the first sheet, respectively.

The method for measuring the thermal contraction rate Sc1 and the thermal contraction rate Sc2 of the second sheet is the same as the method for measuring the thermal contraction rate Sa1 and the thermal contraction rate Sa2 of the first sheet, except that the second sheet is used instead of the first sheet.

The definitions of the longitudinal direction and the transverse direction in the second sheet are the same as those of the longitudinal direction and the transverse direction of the first sheet, except that the first sheet is replaced with the second sheet.

The second sheet may be sheet (short) or long.

Below, each member is demonstrated in detail.

[Second support]

A 2nd support body is a member for supporting a 2nd layer.

Since the aspect of the 2nd support body is the same as the aspect of the 1st support body mentioned above, description is abbreviate|omitted.

[2nd layer]

The second layer is a layer containing a color developer.

A color developer is a compound that does not have a color developing function per se, but has a property of causing the color former to develop color by contacting the color former. As the color developer, an electron-accepting compound is preferable.

Examples of the color developer include inorganic compounds and organic compounds.

As an inorganic compound, clay substances, such as acid clay, activated clay, etherpulgite, zeolite, bentonite, and kaolin, are mentioned, for example.

Examples of the organic compound include metal salts of aromatic carboxylic acids, phenol formaldehyde resins, and metal salts of carboxylated terpene phenol resins.

As the metal salt of aromatic carboxylic acid, 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-di Zinc salts, nickel salts, aluminum salts or calcium salts such as methylbenzyl) salicylic acid, carboxy modified terpene phenol resin or salicylic acid resin which is a reaction product of 3,5-bis(α-methylbenzyl)salicylic acid and benzyl chloride are preferred. .

Among them, as the color developer, a clay substance, a metal salt of an aromatic carboxylic acid, or a metal salt of a carboxylated terpene phenol resin is preferable, and a clay substance or a metal salt of an aromatic carboxylic acid is more preferable. Preferred, acid clay, activated clay or kaolin are particularly preferred.

The content of the color developer in the second layer is preferably 20 to 95% by mass, and more preferably 30 to 90% by mass, based on the total mass of the second layer, in view of the excellent effect of the present invention.

The content of the color developer in the second layer is preferably 0.1 to 30 g/m ² .

When the color developer is an inorganic compound, the content of the developer in the second layer is preferably 3 to 20 g/m ² and more preferably 5 to 15 g/m ² .

When the color developer is an organic compound, the content of the developer in the second layer is preferably 0.1 to 5 g/m ² and more preferably 0.2 to 3 g/m ² .

The second layer may contain other components other than the above-mentioned color developer.

Examples of other components include polymeric binders, pigments, optical whitening agents, antifoaming agents, penetrants, ultraviolet absorbers, surfactants, and preservatives.

As the polymeric binder, for example, a styrene-butadiene copolymer, polyvinyl acetate, polyacrylic acid ester, polyvinyl alcohol, polyacrylic acid, maleic anhydride-styrene copolymer, starch, casein, gum arabic, gelatin, Synthetic polymers and natural polymers, such as carboxymethylcellulose and methylcellulose, are mentioned.

As a pigment, heavy calcium carbonate, light calcium carbonate, talc, and titanium dioxide are mentioned, for example.

The thickness of the second layer is preferably 1 μm to 50 μm, more preferably 2 μm to 30 μm, from the viewpoint of excellent effects of the present invention.

The unit area mass (g/m ² ) of the second layer is preferably 0.5 to 20 g/m ² .

[Method of Forming Second Layer]

A method of forming the second layer is not particularly limited, but a known method may be used.

For example, a method in which a composition for forming a second layer containing a color developer is applied onto a second support and, if necessary, dried.

The composition for forming the second layer may be a dispersion in which a color developer is dispersed in water or the like. The dispersion liquid in which the color developer is dispersed can be prepared by mechanically dispersing the inorganic compound in water when the color developer is an inorganic compound. In the case where the color developer is an organic compound, it can be prepared by mechanically dispersing the organic compound in water or dissolving the organic compound in an organic solvent.

The composition for forming the second layer may contain other components that may be contained in the second layer described above.

The method of applying the composition for forming the second layer is not particularly limited, but a method using a coater used when applying the composition for forming the first layer described above is exemplified.

After applying the composition for forming the second layer onto the second support, the coating film may be subjected to a drying treatment, if necessary. A heat treatment is mentioned as a drying process.

In the above, although the method of forming the 2nd layer on the 2nd support body was demonstrated, it is not limited to the said aspect. For example, after forming the second layer on the temporary support body, the temporary support body may be peeled off to form a second sheet composed of the second layer.

The temporary support is not particularly limited as long as it is a peelable support.

As described above, the first sheet and the second sheet are obtained by laminating the first sheet and the second sheet such that the first layer of the first sheet and the second layer of the second sheet face each other to obtain a laminated body, and the lamination is performed. Used by pressing against a sieve. That is, the first sheet corresponds to a sheet used to measure the pressure together with the second sheet.

The chromaticity in the L ^* a ^* b ^* colorimetric system of the color developing part when pressure is applied to the laminate is not particularly limited, but from the viewpoint of easy color development, it is preferable that the chromaticity a ^* is more than 30 and 80 or less. And, it is preferable that the chromaticity b ^* is more than -50 and 50 or less.

In addition, when measuring the above chromaticity, the first sheet and the second sheet of the laminate after applying pressure are peeled off, and the chromaticity of the colored portion of the second sheet is measured using a densitometer RD-19 (manufactured by Greta Macbeth). . If the second sheet includes a transparent second support and the chromaticity of the color developing portion can be measured from the second support side, the chromaticity of the coloring portion may be measured from the second support side.

<Other members>

The second sheet may have other members in addition to the members described above.

For example, the second sheet may have an adhesive layer between the second support and the second layer to enhance the adhesion between the two.

As an adhesion layer, the adhesion layer which the above-mentioned 1st sheet|seat may have is mentioned, for example.

[Second Embodiment]

3 is a cross-sectional view of an embodiment of a sheet for measuring pressure.

The sheet 30 for pressure measurement has a support 32, a second layer 20 containing a developer, and a first layer 14 containing predetermined microcapsules 13 in this order.

When the sheet 30 for pressure measurement is used, by pressing from at least one of the support body 32 side and the first layer 14 side, the microcapsules 13 are broken in the pressurized region, and the microcapsules 13 The color developing agent contained in the microcapsule 13 comes out, and the color developing reaction proceeds between the color developing agent in the second layer 20. As a result, color develops in the pressed area.

As will be described later, the sheet 30 for pressure measurement only needs to have the first layer 14 and the second layer 20, and may or may not have the support body 32.

In addition, in FIG. 3, although the support body 32 and the 2nd layer 20 are laminated|stacked directly, it is not limited to this aspect. As will be described later, another layer (for example, an adhesion layer) may be disposed between the support body 32 and the second layer 20 .

3 discloses a pressure measuring sheet 30 having a support 32, a second layer 20, and a first layer 14 in this order, but is not limited to this aspect. . It may be a sheet for pressure measurement having a support 32, a first layer 14, and a second layer 20 in this order.

When the sheet for pressure measurement is heated at 220°C for 10 minutes, the thermal contraction rate Sb1 in the longitudinal direction of the sheet for pressure measurement and the heat in the width direction orthogonal to the longitudinal direction of the sheet 22 for pressure measurement It is preferable that the shrinkage ratio Sb2 is -0.5 to 3.0% in all cases.

In addition, the method for measuring the thermal contraction rate Sb1 and the thermal contraction rate Sb2 of the pressure measurement sheet is the same as the measurement method for the thermal contraction rate Sa1 and the thermal contraction rate Sa2 of the first sheet described above, except that the measurement target is changed to the pressure measurement sheet.

The first layer 14 and the second layer 20 in the sheet 30 for pressure measurement are the same members as the first layer 14 and the second layer 20 described in the first embodiment described above. Therefore, the description is omitted.

Below, the support body 32 is mainly demonstrated in detail.

[support body]

A support body is a member for supporting a 1st layer and a 2nd layer. In addition, when the laminate of the first layer and the second layer can be handled by itself, the pressure measurement sheet need not have a support.

Since the suitable aspect of a support body is the same as that of the above-mentioned 1st support body, description is abbreviate|omitted.

[Method of Manufacturing Sheet for Pressure Measurement]

The method for producing the sheet for pressure measurement is not particularly limited, but known methods may be used.

For example, after applying a composition for forming a second layer containing a color developer on a support, applying a drying treatment if necessary, forming a second layer on the support, and then forming a first layer containing predetermined microcapsules. A method of further applying the composition for layer formation on the second layer and, if necessary, performing a drying treatment to form the first layer is exemplified. In addition, the method of forming the microcapsule is as described above.

The method for forming the first layer using the composition for forming the first layer is as described in the first embodiment. Moreover, the formation method of the 2nd layer using the composition for 2nd layer formation is also as having demonstrated in 1st Embodiment.

<Other members>

The sheet for measuring pressure may include other members in addition to the members described above.

For example, the sheet for pressure measurement may have an adhesive layer between the support and the second layer to enhance adhesion between the two.

As an adhesion layer, the adhesion layer which the above-mentioned 1st sheet|seat may have is mentioned, for example.

[Usage]

The sheet set for measuring pressure of the present invention can be used for various purposes, and is used, for example, for verification or management of various manufacturing processes including a hot press in the process. More specifically, pressure distribution confirmation in the lamination process in the field of batteries (lithium ion batteries, fuel cells), pressure distribution confirmation in the lamination process in the field of printed wiring boards (FPC, BWB), wiring take-out Confirmation of pressure distribution in thermocompression bonding processes such as ACF bonding and lamination, and confirmation of pressure distribution at mold clamping parts.

[Third Embodiment]

As a third embodiment, a dispersion containing microcapsules containing a color former (hereinafter also simply referred to as “first dispersion”) used to form a layer used in combination with a layer containing a color developer (pressure dispersion liquid for forming a measurement layer).

[First dispersion liquid]

The first dispersion is a dispersion of microcapsules containing microcapsules containing a coloring agent containing a specific compound, and the thermal decomposition temperature of the capsule walls of the microcapsules is 250°C or higher.

Each component contained in the first dispersion has the same meaning as the component contained in the first layer described above, and the suitable range is also the same.

Examples of the first dispersion liquid include the above-described composition for forming the first layer.

The first dispersion preferably contains a solvent. Examples of the solvent contained in the first dispersion include water and organic solvents.

Like the composition for forming the first layer, the first dispersion is used to form a layer used for pressure measurement (corresponding to the first layer described above).

[Second Dispersion]

The first dispersion may be used in combination with a dispersion (hereinafter, simply referred to as "second dispersion") used to form a layer containing a color developer. That is, the first dispersion and the second dispersion may be used as a set (dispersion set).

The second dispersion is a dispersion containing a color developer.

Each component contained in the second dispersion has the same meaning as the component contained in the above-mentioned second layer, and the suitable range is also the same.

Examples of the second dispersion liquid include the composition for forming the second layer described above.

The second dispersion preferably contains a solvent. Examples of the solvent contained in the second dispersion include water and organic solvents.

In view of the fact that the first dispersion does not clog when used by spraying or the like, it is preferable that the first dispersion does not contain coarse particles.

In view of the above, the volume-based median diameter (D50) of the microcapsule is preferably 1 to 80 μm, more preferably 5 to 70 μm, and still more preferably 10 to 50 μm.

In view of the above, it is preferable that the second dispersion liquid does not contain coarse particles.

In view of the above, as the color developer contained in the second dispersion, an organic compound is preferable. As the organic compound, a metal salt of an aromatic carboxylic acid is preferable, a metal salt of salicylate is more preferable, and a zinc salt of salicylate is still more preferable.

The first dispersion can also be applied to an object for which pressure measurement is difficult with a sheet set for pressure measurement or the like. More specifically, a required amount of the first dispersion is applied to an area of the pressure measurement object that requires pressure measurement regardless of the surface shape of the pressure measurement object, and a layer containing the microcapsule is formed in the area. By doing so, it is possible to measure the pressure. In particular, it can be suitably applied to the case of measuring the pressure in a curved surface.

[Fourth Embodiment]

As a fourth embodiment, microcapsules containing a coloring agent used to form a layer for pressure measurement, and a dispersion containing a color developing agent (hereinafter, simply referred to as "third dispersion") (pressure measurement layer formation) dispersion solution).

Each component contained in the third dispersion has the same meaning as the component contained in the above-described first layer or second layer, and the suitable range is also the same.

As an aspect of the microcapsules contained in the third dispersion, an aspect of the microcapsules contained in the composition for forming the first layer is exemplified.

As an aspect of the color developer contained in the third dispersion, an aspect of the color developer contained in the composition for forming the second layer can be cited.

The third dispersion preferably contains a solvent. Examples of the solvent contained in the third dispersion include water and organic solvents.

Examples of the third dispersion include an aspect in which the above-described composition for forming the first layer is mixed with a color developer, and an aspect in which the composition for forming the first layer and the above-described composition for forming the second layer are mixed.

It is preferable that the third dispersion does not contain coarse particles in terms of not clogging when the first dispersion is applied by spraying or the like.

In view of the above, the volume-based median diameter (D50) of the microcapsule is preferably 1 to 50 µm.

In view of the above, as the color developer contained in the third dispersion, an organic compound is preferable. As the organic compound, a metal salt of an aromatic carboxylic acid is preferable, a metal salt of salicylate is more preferable, and a zinc salt of salicylate is still more preferable.

Since the third dispersion includes microcapsules containing a color former and a color developer, pressure can be measured only with a layer formed by applying the third dispersion.

That is, the third dispersion, like the first and second dispersions, can also be applied to an object for which pressure measurement is difficult with sheets such as a pressure measurement sheet set and a pressure measurement sheet. More specifically, it is possible to measure pressure by applying a necessary amount of the third dispersion to the area of the pressure measurement object requiring pressure measurement and forming a layer on the area regardless of the surface shape of the pressure measurement object. doing it

The above-described first dispersion, second dispersion, and third dispersion are mainly used for pressure measurement at the time of manufacturing automobiles, high-temperature heat press, heat press, and bonding, but can be used for various applications including other applications. there is.

For example, confirmation of pressure distribution in the molding process or assembly process of various constituent members, bodies, etc. in the manufacture of vehicles such as automobiles or aircraft, and confirmation of pressure distribution in the assembly process of building materials. , Confirmation of pressure distribution in processes such as curved surface processing of electronic products, confirmation of impact force applied to cargo along with transportation, confirmation per mold in manufacturing metal products, confirmation per mold during molding and processing of resin products , Confirmation of pressure distribution in tableting of tablets in pharmaceuticals, confirmation of pressure distribution on the surface of furniture such as sofa seating, confirmation of pressure in stationery such as confirmation of grip force applied to writing instruments, etc., balls made of elastic materials Confirmation of the impact force applied to sporting goods such as the back, and confirmation of gaps (clearance) between upper and lower teeth in dental goods.

Example

The present invention will be described in more detail below based on examples. The materials, usage amount, ratio, process content, process procedure, etc. shown in the following examples can be appropriately changed without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the Examples shown below. In the following, "parts" and "%" are based on mass unless otherwise specified.

[Example 1]

[Preparation of microcapsules containing coloring agents]

3',6'-bis(diethylamino)-2-(4-nitrophenyl)spiro[iso Indole-1,9'-xanthene] -3-one (Hodogaya Chemical Industry Co., Ltd., Pink-DCF) (3 parts by mass), 6'-(diethylamino)-1',3'-dimethylfluorane (Hodogaya Chemical Industry Co., Ltd., Orange-DCF) (4 parts by mass) and 2-(2'-hydroxy-5'-methylphenyl) benzotriazole (Johoku Chemical Industry Co., Ltd., JF-77-P) as an ultraviolet absorber ) (3 parts by mass) was dissolved to obtain solution A.

Next, synthetic isoparaffin (made by Idemitsu Kosan Co., Ltd., IP solvent 1620) (13 parts by mass) was added to the stirred solution A to obtain a solution B. Further, a trimethylolpropane adduct of tolylene diisocyanate dissolved in ethyl acetate (6 parts by mass) (manufactured by DIC Corporation, Vernock D-750, solid content concentration 75% by mass) (1.6 parts by mass) and Milio Solution C was obtained by adding Nate MR-200 (manufactured by Tosoh Corporation) (3.7 parts by mass) to the stirring solution B. In addition, Milionate MR-200 is a mixture of diphenylmethane diisocyanate and polymethylene polyphenyl polyisocyanate. Then, the solution C was added to a solution in which polyvinyl alcohol (JP-45, manufactured by Nippon Sacubi-Pobal Co., Ltd.) (4 parts by mass) was dissolved in water (140 parts by mass), and emulsified and dispersed. Water (200 parts by mass) was added to the emulsion after emulsification and dispersion, and the mixture was heated to 70°C while stirring, and cooled after stirring for 1 hour. Furthermore, the concentration was adjusted by adding water, and a color former containing microcapsule liquid having a solid content concentration of 25% was obtained.

The volume-based median diameter (D50) of the obtained color coupler encapsulating microcapsule was 20 µm. The volume-based median diameter (D50) was measured by the method described above with an optical microscope.

[Production of sheet set for pressure measurement]

<Production of the first sheet>

Microcapsule liquid containing color coupler (25% solid content concentration) (43 parts by mass), water (15 parts by mass), colloidal silica (manufactured by Nissan Chemical Industries, Ltd., Snowtex (registered trademark) 30, 30% solid content concentration) (5.7 parts by mass) ), 10 mass% aqueous solution (1.8 parts by mass) of Polymalone 482 (Arakawa Chemical Industry Co., Ltd.), 10 mass% aqueous solution (24 parts by mass) of carboxymethylcellulose Na (Daiichi Kogyo Seiyaku Co., Ltd., Serogen EP) ), 1 mass% aqueous solution (0.7 parts by mass) of Rafizol A-90 (manufactured by Nichiyu Co., Ltd.) and 1 mass% of Neugen LP-70 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., polyoxyalkylene alkyl ether surfactant) A composition for forming a first layer was obtained by mixing the aqueous solution (0.7 parts by mass) and stirring for 2 hours.

Further, on a polyethylene naphthalate sheet having a thickness of 75 μm (Teijin Film Solutions, Theonex (registered trademark) Q53) as a first support, an adhesion layer forming composition containing styrene butadiene latex was applied and dried to a thickness of 100 nm. An adhesive layer of was formed on the first support to obtain a first support having an adhesive layer.

On the adhesive layer of the first support having the obtained adhesive layer, the first layer-forming composition was applied by a bar coater and dried to form a first layer of about 500 nm to prepare a first sheet.

<Production of the second sheet>

Sulfuric acid-treated activated clay (200 parts by mass) as a developer, sodium hexametaphosphate (1 part by mass), 10% by mass aqueous solution of sodium hydroxide (30 parts by mass) and water (290 parts by mass) were mixed into whole particles using a sand grinder A dispersion was prepared by dispersing so that the average particle diameter of was 2 μm.

Subsequently, to the obtained dispersion, Nipol LX-814 (Nippon Zeon Co., Ltd.) 19 mass% aqueous dispersion) (180 mass parts), Polymalone 482 (Arakawa Chemical Industry Co., Ltd.) 3.3 mass% aqueous solution (220 mass parts), carboxyl 1% by mass aqueous solution (80 parts by mass) of methylcellulose Na (made by Daiichi Kogyo Seiyaku Co., Ltd., Serogen EP), 15 mass% aqueous solution (4.7 parts by mass) of sodium alkylbenzenesulfonate (made by Daiichi Kogyo Seiyaku Co., Ltd., Neogen T) parts by mass) and a 1% by mass aqueous solution (70 parts by mass) of Neugen LP70 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., polyoxyalkylene alkyl ether type surfactant), to obtain a composition for forming a second layer.

The composition for forming the second layer was applied onto a polyethylene naphthalate sheet having a thickness of 75 μm (Theonex (registered trademark) Q53, manufactured by Teijin Film Solutions Co., Ltd.) as a second support so that the solid content coating amount was 12.0 g/m ² , and dried. to form a second layer to obtain a second sheet.

[Examples 2-24, Comparative Examples 1-2, Reference Examples 1-2]

As shown in Table 1, the first sheet and the first sheet of each example, each comparative example, and each reference example were followed in the same procedure as in Example 1, except that various conditions such as each material and the content of each material were changed. 2 sheets were produced.

For Comparative Example 1, reference was made to Comparative Example 1 described in Patent Literature 2. For Comparative Example 2, Example 13 described in Patent Literature 3 was referred to.

[Comparative Example 3]

As in the example described in Patent Literature 1, Prescale LLW (manufactured by Fujifilm Corporation) was used as a sheet set for pressure measurement.

[measurement and evaluation]

[high temperature aptitude]

The first sheet obtained in the above (preparation of the first sheet) and the second sheet obtained in the above (preparation of the second sheet) were cut into a size of 5 cm x 5 cm, and a second sheet was formed on the surface of the color layer of the first sheet. and the surface of the color developing layer of the second sheet were overlapped so as to face each other to obtain a laminate. The obtained laminate was placed on a hot plate at 200°C, a ring-shaped SUS mold having a width of 5 mm was further placed on the laminate, and the pressure was measured at a pressure of 2.5 MPa for 5 seconds. The obtained laminate was lowered from the hot plate, the superimposed first sheet and second sheet were peeled off, the shape of the color development region of the second sheet was visually observed, and evaluation was performed according to the following evaluation criteria.

In addition, the shape of the colored region of the second sheet was visually checked in the same procedure as above except that the pressure measurement time was changed to 2 minutes, and evaluation was performed according to the following evaluation criteria.

(Evaluation standard)

A: In either case the pressure measurement time is 5 seconds or 2 minutes, it can be well recognized that the shape of the color region is the same ring shape as the SUS mold, and the color region when the pressure measurement time is 5 seconds No change was observed in the color and the color of the color development area when the pressure measurement time was 2 minutes.

B: In both cases where the pressure measurement time was 5 seconds or 2 minutes, the outline of the area where the color was developed by pressing was slightly unclear, but it was recognizable as having the same ring shape as the SUS mold, and the pressure measurement time was 5 seconds No change was observed in the color of the color development area when the pressure was measured for 2 minutes and in the color of the color development area when the pressure measurement time was 2 minutes.

C: In either case of pressure measurement time of 5 seconds or 2 minutes, the outline of the area where the color developed by pressing is unclear, and the shape of the color area is partially identical to that of the SUS mold in some places where the ring shape cannot be recognized, but mostly It can be recognized that the ring shape is the same as that of the SUS mold at the location of , and there is no change in the color of the color development area when the pressure measurement time is 5 seconds and the color of the color development area when the pressure measurement time is 2 minutes. did not

D: Even when the pressure measurement time is 5 seconds or 2 minutes, it is not recognized that the color development area is the same ring shape as the SUS mold, and the color and pressure of the color development area when the pressure measurement time is 5 seconds are measured. A change was observed in the color of the color development area when the time was 2 minutes.

[Gradation at high temperature]

The first sheet obtained in the above (preparation of the first sheet) and the second sheet obtained in the above (preparation of the second sheet) were cut into a size of 5 cm x 5 cm, and a second sheet was formed on the surface of the color layer of the first sheet. and the color developing layer of the second sheet were overlapped so that the surface thereof faced each other, and the obtained sheet was pressed at a temperature of 200° C. and a pressure of 0.5 MPa, 1.5 MPa, or 2.5 MPa using a hot press to develop color. Next, the overlapped first sheet and second sheet were peeled off, and the concentration (DA) of the colored portion of the obtained second sheet was measured at each pressure using a densitometer RD-19 (manufactured by Greta Macbeth). .

In addition, apart from the above, the initial concentration (DB) of the unused second sheet was measured in the same manner as described above. Then, the initial concentration (DB) was subtracted from the concentration (DA) of the colored part at each pressure to determine the color concentration (ΔD), and evaluated according to the following evaluation criteria. In addition, "B" is a practically permissible range.

(Evaluation standard)

A: At pressures of 0.5 MPa, 1.5 MPa and 2.5 MPa, ΔD is 0.4 or more

B: Two of the pressures of 0.5 MPa, 1.5 MPa and 2.5 MPa have ΔD of 0.1 or more and less than 0.4

C: At pressures of 0.5 MPa, 1.5 MPa, and 2.5 MPa, two of them have a ΔD of less than 0.1

[Light fastness after color development]

The first sheet obtained in the above (preparation of the first sheet) and the second sheet obtained in the above (preparation of the second sheet) were cut into a size of 5 cm × 5 cm, and a second sheet was formed on the surface of the color layer of the first sheet. and the color development layer of the second sheet were overlapped so that the surface thereof faced each other, and the obtained sheet was pressed at a temperature of 200° C. and a pressure of 1.0 MPa using a hot press to develop color. Next, the overlapped first and second sheets are lowered from the hot plate, the overlapped first and second sheets are peeled off, and the colored portion of the second sheet is image analysis system FPD-8010J manufactured by Fujifilm Corporation. The image was read using After that, the obtained second sheet was stored at room temperature for one week. Then, the image was similarly read for the colored portion of the second sheet after storage, and image data before and after one week were compared and evaluated according to the following evaluation criteria.

(Evaluation standard)

A: The color and density also did not change.

B: At least one of color and density changed.

[Thermal decomposition temperature]

The thermal decomposition temperature of the capsule wall of the microcapsule was measured in the same manner as described above.

[Measurement of heat shrinkage rate]

Samples obtained by cutting the first sheets produced in each example, each comparative example, and each reference example so that the length in the longitudinal direction of the first sheet is 150 mm and the length in the width direction is 20 mm are 3 prepared every

A position A extending approximately 25 mm along a direction parallel to the long side from the midpoint (starting point) of one short side of the sample to the midpoint of the other short side, and one short side from the midpoint (starting point) of the other short side of the sample. Marked lines were attached to each of the positions B, which advanced about 25 mm along the direction parallel to the long side toward the midpoint of . At this time, the distance between position A and position B (distance between marked lines) was 100 mm ± 2 mm.

This was used as a sample for measuring the thermal contraction rate Sa1 in the longitudinal direction of the first sheet.

After heating the obtained sample for measurement at 220 ° C. for 10 minutes, the sample for measurement was returned to room temperature (23 ° C.), the distance between the marked lines of the sample for measurement was measured, and the thermal contraction rate Sa3 was calculated according to the following formula.

Thermal contraction rate Sa3 [%] = 100 × {(distance between gauge lines in measurement sample before heating) - (distance between gauge lines in measurement sample after heating)}/(between gauge lines in measurement sample before heating) distance)

The arithmetic average value of the thermal contraction rate Sa3 of the three measurement samples was obtained, and this was determined as the thermal contraction rate Sa1. In addition, the distance between marked lines was measured to the unit of 0.1 mm.

In addition, three samples were prepared by cutting the first sheet produced in each example so that the length of the first sheet in the width direction was 150 mm and the length in the longitudinal direction was 20 mm. Then, in the same manner as the sample for measurement of thermal contraction rate Sa1, a marked line was attached to the surface of each sample.

This was used as a sample for measuring the thermal contraction rate Sa2 in the width direction of the first sheet.

After heating the obtained sample for measurement at 220 ° C. for 10 minutes, the sample for measurement was returned to room temperature (23 ° C.), the distance between the marked lines of the sample for measurement was measured, and the thermal contraction rate Sa4 was calculated according to the following formula.

Thermal contraction rate Sa4 [%] = 100 × {(distance between gauge lines in measurement sample before heating) - (distance between gauge lines in measurement sample after heating)}/(between gauge lines in measurement sample before heating) distance)

The arithmetic average value of the thermal contraction rate Sa4 of the three measurement samples was obtained, and this was determined as the thermal contraction rate Sa2. In addition, the distance between marked lines was measured to the unit of 0.1 mm.

In all examples, when the first sheet is heated at 220° C. for 10 minutes, the heat shrinkage rate Sa1 in the longitudinal direction of the first sheet and the heat in the width direction orthogonal to the longitudinal direction of the first sheet Shrinkage ratio Sa2 was all in the range of -0.5 to 3.0.

In Table 1, each material shows the following.

[Various ingredients]

[profit]

Polyurethane Urea

melamine resin

<Wall Material A>

D-750: corresponds to trimethylolpropane adduct of tolylene diisocyanate (manufactured by DIC, Vernock D-750, solid content concentration: 75% by mass) and polyisocyanate A.

melamine

<Wall Material B>

MR-200: Milionate MR-200 (manufactured by Tosoh Corporation) corresponds to polyisocyanate B.

formaldehyde

[coloring agent]

<Specific compound>

Orange-DCF: the following compound (6'-(diethylamino)-1',3'-dimethylfluorane, manufactured by Hodogaya Chemical Industry Co., Ltd.)

RED500: the compound of

RED520: the compound below

RED550: the compound of

[Formula 7]

<Other coloring agents>

Pink-DCF: the following compound (3',6'-bis(diethylamino)-2-(4-nitrophenyl)spiro[isoindole-1,9'-xanthen]-3-one, Hodogaya Kaga Ku High School Festival)

Color former A: 3,3-bis (2-methyl-1-octyl-3-indolyl) phthalide

Color former B: the following compound

[Formula 8]

In Table 1, the "mass ratio (A)/(B)" column shows the mass ratio of the mass of wall material A to the mass of wall material B (mass of wall material A/mass of wall material B).

The compound described in the "specific compound (a)" column represents a compound corresponding to the compound represented by formula (1). The compound described in the column of "other color formers (b)" represents a color former that does not correspond to the compound represented by formula (1).

The "mass ratio (a)/(b)" column indicates the mass ratio of the mass of the specific compound (a) to the mass of the other color coupler (b) (mass of the specific compound (a)/mass of the other color coupler (b)) indicates

[Table 1]

As shown in Table 1, it was confirmed that the desired effect was obtained when the sheet set for measuring pressure of the present invention was used.

From the comparison of Examples 1 to 6, it is confirmed that the effect of the present invention is more excellent when the thermal decomposition temperature of the capsule wall exceeds 250°C, and the effect of the present invention is more excellent when the thermal decomposition temperature of the capsule wall is 260°C or higher. that has been confirmed

From the comparison of Examples 6 to 10, it was confirmed that the light resistance after color development was excellent when the content of the specific compound was 70% by mass or more with respect to the total mass of the color former.

From the comparison of Examples 6 and 12 to 16, it was confirmed that the effect of the present invention is more excellent when the thickness of the capsule wall of the microcapsule is 80 to 300 nm.

Further, from the same comparison, when the thickness of the capsule wall of the microcapsule was 80 to 250 nm, it was confirmed that the gradation at high temperature was excellent, and when the thickness was 100 to 200 nm, it was confirmed that the gradation at high temperature was better.

Set of 10 sheets for pressure measurement
12 first support
14 first floor
16 first sheet
18 second support
20 second floor
22 second sheet
30 seat for pressure measurement
32 support
20 second floor
22 second sheet
30 seat for pressure measurement
32 support

Claims (20)

a first sheet having a first layer including microcapsules containing a color former;
A sheet set for pressure measurement comprising a second sheet having a second layer containing a developer,
The color former contains a compound represented by formula (1),
The sheet set for pressure measurement, wherein the thermal decomposition temperature of the capsule wall of the microcapsule is 250 ° C. or higher.
[Formula 1]

In Formula (1), R ¹ represents an alkyl group which may have a substituent. R ³ represents -NR ^A R ^B . R ^A and R ^B each independently represent an alkyl group which may have a substituent or an aryl group which may have a substituent. R ² and R ⁴ each independently represent a halogen atom. Q represents a benzene ring or a naphthalene ring. X represents -O- or -NR ⁵ -. R ⁵ represents an alkyl group which may have a substituent or an aryl group which may have a substituent. p and q represent the integer of 0-4 each independently. r represents the integer of 1-3. s represents an integer of 0 to 3. However, p+q is an integer of 0 to 4, and r+s is an integer of 1 to 4. The method of claim 1,
When the first sheet is heated at 220 ° C. for 10 minutes, the thermal contraction rate Sa1 in the longitudinal direction of the first sheet and the thermal contraction rate Sa2 in the width direction orthogonal to the longitudinal direction of the first sheet, A set of sheets for pressure measurement, all from -0.5 to 3.0%. According to claim 1 or claim 2,
The sheet set for pressure measurement, wherein the capsule walls of the microcapsules contain at least one selected from the group consisting of polyurethane urea and melamine resin having a polymethylene polyphenylene structure. The method according to any one of claims 1 to 3,
The sheet set for measuring pressure, wherein the capsule walls of the microcapsules contain a resin having structure A or structure B.
Structure A: A structure formed by reacting an aromatic or alicyclic diisocyanate, a compound having three or more active hydrogen groups in one molecule, and polymethylene polyphenyl polyisocyanate.
Structure B: Structure formed by reacting melamine with formaldehyde. The method according to any one of claims 1 to 4,
A sheet set for measuring pressure, wherein the thickness of the capsule wall of the microcapsule is 80 to 300 nm. The method according to any one of claims 1 to 5,
A sheet set for measuring pressure, wherein the content of the compound represented by the formula (1) is 70% by mass or more with respect to the total mass of the color former. A first layer comprising microcapsules containing a coloring agent;
A sheet for measuring pressure having a second layer containing a developer,
The color former contains a compound represented by formula (1),
The sheet for pressure measurement, wherein the thermal decomposition temperature of the capsule wall of the microcapsule is 250 ° C. or higher.
[Formula 2]

In Formula (1), R ¹ represents an alkyl group which may have a substituent. R ³ represents -NR ^A R ^B . R ^A and R ^B each independently represent an alkyl group which may have a substituent or an aryl group which may have a substituent. R ² and R ⁴ each independently represent a halogen atom. Q represents a benzene ring or a naphthalene ring. X represents -O- or -NR ⁵ -. R ⁵ represents an alkyl group which may have a substituent or an aryl group which may have a substituent. p and q represent the integer of 0-4 each independently. r represents the integer of 1-3. s represents an integer of 0 to 3. However, p+q is an integer of 0 to 4, and r+s is an integer of 1 to 4. The method of claim 7,
When the sheet for pressure measurement is heated at 220°C for 10 minutes, the thermal contraction rate Sb1 in the longitudinal direction of the sheet for pressure measurement and the thermal contraction rate in the width direction orthogonal to the longitudinal direction of the sheet for pressure measurement A sheet for pressure measurement in which Sb2 is -0.5 to 3.0% in all cases. According to claim 7 or claim 8,
The sheet for pressure measurement, wherein the capsule walls of the microcapsules contain at least one selected from the group consisting of polyurethane urea having a polymethylene polyphenylene structure and melamine resin. The method according to any one of claims 7 to 9,
The sheet for measuring pressure, wherein the capsule walls of the microcapsules contain a resin having structure A or structure B.
Structure A: A structure formed by reacting an aromatic or alicyclic diisocyanate, a compound having three or more active hydrogen groups in one molecule, and polymethylene polyphenyl polyisocyanate.
Structure B: Structure formed by reacting melamine with formaldehyde. The method according to any one of claims 7 to 10,
A sheet for measuring pressure, wherein the thickness of the capsule wall of the microcapsule is 80 to 300 nm. The method according to any one of claims 7 to 11,
The sheet for measuring pressure, wherein the content of the compound represented by the formula (1) is 70% by mass or more with respect to the total mass of the color former. As a microcapsule containing a coloring agent,
The color former contains a compound represented by formula (1),
The thermal decomposition temperature of the capsule wall of the microcapsule is 250 ° C. or higher, the microcapsule.
[Formula 3]

In Formula (1), R ¹ represents an alkyl group which may have a substituent. R ³ represents -NR ^A R ^B . R ^A and R ^B each independently represent an alkyl group which may have a substituent or an aryl group which may have a substituent. R ² and R ⁴ each independently represent a halogen atom. Q represents a benzene ring or a naphthalene ring. X represents -O- or -NR ⁵ -. R ⁵ represents an alkyl group which may have a substituent or an aryl group which may have a substituent. p and q represent the integer of 0-4 each independently. r represents the integer of 1-3. s represents an integer of 0 to 3. However, p+q is an integer of 0 to 4, and r+s is an integer of 1 to 4. The method of claim 13,
A microcapsule wherein the capsule wall of the microcapsule contains at least one selected from the group consisting of polyurethane urea and melamine resin having a polymethylene polyphenylene structure. According to claim 13 or claim 14,
The microcapsule wherein the capsule wall of the microcapsule contains a resin having structure A or structure B.
Structure A: A structure formed by reacting an aromatic or alicyclic diisocyanate, a compound having three or more active hydrogen groups in one molecule, and polymethylene polyphenyl polyisocyanate.
Structure B: Structure formed by reacting melamine with formaldehyde. The method according to any one of claims 13 to 15,
The thickness of the capsule wall of the microcapsule is 80 to 300 nm, the microcapsule. The method according to any one of claims 13 to 16,
A microcapsule in which the content of the compound represented by the formula (1) is 70 mass% or more with respect to the total mass of the color former. A dispersion liquid comprising the microcapsules according to any one of claims 13 to 17. The method for manufacturing the sheet set for measuring pressure according to any one of claims 1 to 6, comprising a step of forming the first layer using the dispersion according to claim 18. The method for producing the sheet for pressure measurement according to any one of claims 7 to 12, comprising a step of forming the first layer using the dispersion according to claim 18.

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