JP2023011737A - Assembly, sheet set for pressure measurement, and sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an assembly having a sheet having a layer containing microcapsules including a color developing agent wound around a winding core which suppresses the breakage of the microcapsules when impact due to falling is given thereto, a sheet set for pressure measurement, and a sheet.

SOLUTION: An assembly has a winding core, and a roll of a first sheet formed by winding a long first sheet around the winding core, wherein the first sheet has a long resin substrate and a first layer containing microcapsules including a color developing agent arranged on the resin substrate, and rigidity in a width direction of the first sheet is 150 mN or more.

SELECTED DRAWING: None

COPYRIGHT: (C)2023,JPO&INPIT

Description

The present invention relates to an assembly, a pressure measuring sheet set and a sheet.

2. Description of the Related Art In recent years, the need to measure pressure distribution tends to increase due to the sophistication and high definition of products.
Pressure measuring sheet sets are known for measuring the distribution of pressure. The sheet set for pressure measurement is composed of a sheet having a layer containing microcapsules containing a color former and a sheet having a layer containing a color developer. As described in Patent Document 1, the sheet is often transported and stored while being wound around a winding core.

JP 2009-173307 A

On the other hand, in recent years, as the coloring properties of sheets have improved, more attention has been required in handling sheets. For example, when the sheet receives an impact, the microcapsules are easily destroyed, and the sheet no longer functions as a pressure measurement sheet.
The present inventors evaluated the characteristics of an assembly including a roll of a sheet obtained by winding a sheet having a layer containing microcapsules encapsulating a color former in a winding core as described in Patent Document 1. , have found that the microcapsules may break when subjected to impact due to dropping during transportation and handling.

In view of the above circumstances, the present invention provides an assembly having a sheet having a layer containing microcapsules enclosing a color former wound around a winding core, wherein the microcapsules can be An object of the present invention is to provide an assembly in which breakage of a capsule is suppressed.
Another object of the present invention is to provide a sheet set and sheet for pressure measurement.

As a result of intensive studies on the above problem, the inventors have found that the above problem can be solved by the following configuration.

(1) a winding core;
An assembly comprising a first sheet roll formed by winding a long first sheet around a winding core,
The first sheet has an elongated resin substrate and a first layer containing microcapsules containing a color former disposed on the resin substrate,
The assembly, wherein the stiffness in the width direction of the first sheet is 150 mN or more.
(2) The assembly according to (1), wherein the stiffness in the width direction of the first sheet is greater than the stiffness in the longitudinal direction of the first sheet.
(3) The assembly according to (2), wherein the longitudinal stiffness of the first sheet is 180 mN or less.
(4) The assembly according to any one of (1) to (3), wherein the stiffness in the width direction of the first sheet is 165 mN or more.
(5) The method according to any one of (1) to (4), further comprising a pair of spacers disposed between the first sheets of the roll of the first sheet and spaced apart in the width direction of the first sheet. Assembly.
(6) The assembly according to (5), wherein the thickness of the spacer is 1-5 mm.
(7) The assembly according to any one of (1) to (6), wherein the first sheet further has an adhesion layer between the resin substrate and the first layer.
(8) The assembly according to (7), wherein the adhesion layer contains a resin having repeating units derived from styrene or a derivative thereof.
(9) The assembly according to (7) or (8), wherein the adhesion layer has a thickness of 0.01 to 2.0 μm.
(10) The assembly according to any one of (1) to (9), further comprising a pair of flange members fixed to opposite ends of the winding core.
(11) the assembly according to any one of (1) to (10);
and a second sheet having a second layer comprising a developer.
(12) a first sheet having an elongated resin substrate and a first layer containing microcapsules disposed on the resin substrate and containing a color former;
a second sheet having a second layer containing a color developer, comprising:
A sheet set for pressure measurement, wherein the stiffness in the width direction of the first sheet is 150 mN or more.
(13) A sheet having an elongated resin substrate and a first layer containing microcapsules disposed on the resin substrate and containing a color former,
A sheet having a stiffness of 150 mN or more in the width direction of the first sheet.

According to the present invention, there is provided an assembly having a sheet having a layer containing microcapsules enclosing a color former wound around a winding core, wherein the microcapsules are destroyed even when impacted by dropping. A restrained assembly can be provided.
The present invention can also provide a sheet set and sheet for measuring pressure.

1 is a perspective view showing one embodiment of an assembly of the present invention; FIG. FIG. 11 is a perspective view showing one embodiment of a flange member; 4 is a top view of the flange member of FIG. 3; FIG. FIG. 11 is a perspective view showing another embodiment of a flange member; FIG. 4 is a cross-sectional view showing one embodiment of a first sheet; FIG. 6 is a top view of the first sheet of FIG. 5; 4 is a partially enlarged cross-sectional view of the first sheet; FIG.

The present invention will be described in detail below.
In this specification, the numerical range represented by "-" means a range including the numerical values before and after "-" as lower and upper limits.
In addition, in the numerical ranges described stepwise in this specification, the upper limit or lower limit described in a certain numerical range may be replaced with the upper limit or lower limit of the numerical range described in other steps. good. Moreover, in the numerical ranges described in this specification, the upper limit or lower limit described in a certain numerical range may be replaced with the values shown in the examples.
Various components described later may be used singly or in combination of two or more. For example, the later-described polyisocyanates may be used singly or in combination of two or more.

A feature of the assembly of the present invention is that the stiffness in the width direction of the first sheet wound around the winding core is adjusted.
Although the details of why the desired effect can be obtained by adjusting the rigidity are unknown, if the rigidity is equal to or higher than a predetermined value at the time of collision due to a drop, even if the impact is applied to the roll of the first sheet, By suppressing the deformation of the first sheet in the width direction, it is believed that the deformation of the first layer is suppressed, and as a result, the breakage of the microcapsules is suppressed.

FIG. 1 is a perspective view showing one embodiment of the assembly of the present invention.
The assembly 10 is formed by winding a hollow cylindrical winding core 12, a pair of flange members 14 fixed to both ends of the winding core 12, and a long first sheet to be described later on the winding core 12. and a roll 16 of a first sheet.
FIG. 2 shows a perspective view of the flange member 14 shown in FIG. FIG. 3 shows a top view of the flange member 14. As shown in FIG. The flange member 14 has a substrate (flange) 18 , an insertion section 20 arranged on the substrate 18 , and projections 22 arranged on the surface (outer peripheral surface) of the insertion section 20 .
The insertion portion 20 of the flange member 14 can be inserted into the hollow portion of the hollow cylindrical winding core 12 . In FIG. 1, the insertion portion 20 of the flange member 14 is inserted into the hollow portion of the winding core 12, and the protruding portion 22 of the insertion portion 20 contacts the inner peripheral surface of the winding core 12, whereby the winding core 12 and the flange are separated. The member 14 is fixed.
Each member will be described in detail below.

<Winding core 12>
A first sheet is wound around the winding core 12 .
Materials for the winding core 12 include plastic, paper, wood, and metal. Among them, paper is preferable because the fixing strength between the winding core and the flange member can be adjusted appropriately. Examples of paper include paper tube base paper and resin-impregnated paper.
The size of the winding core 12 is not particularly limited, but the outer diameter (outside diameter of the winding core) is preferably 50 to 350 mm, more preferably 85 to 90 mm.
When the winding core has a shape other than a cylindrical shape, the outer diameter corresponds to the diameter of the circumscribed circle of the winding core.

The inner diameter of the cylindrical winding core 12 is preferably 45 to 345 mm, more preferably 80 to 85 mm.

Although the winding core 12 in FIG. 1 has a hollow cylindrical shape, the shape is not limited as long as the first sheet can be wound.
For example, the winding core may have a polygonal prism shape. Also, the winding core may be solid.

<Flange member 14>
The flange members 14 are fixed to both ends of the winding core 12 . As described above, in FIG. 1, the winding core 12 and the flange member 14 are fixed by the projections 22 in the flange member 14 contacting the inner peripheral surface of the winding core 12 .

Materials for the flange member 14 include plastic, paper, wood, and metal. Among them, plastic is preferable. Plastics include polypropylene, polyethylene, and polyethylene terephthalate, with polypropylene being preferred.
It is preferable that the inserting portion 20 and the projecting portion 22, which will be described later, are also made of the above material.

Flange member 14 includes a substrate 18 .
In FIG. 2, the substrate 18 has an octagonal shape, but the shape is not particularly limited, and may be a circular shape or a polygonal shape other than the octagonal shape (for example, a hexagonal shape). .
Although the thickness of the substrate 18 is not particularly limited, it is preferably 1 to 50 mm, more preferably 2 to 20 mm.
The size of the substrate 18 is not particularly limited, but it is generally preferred that it is larger than the outer diameter of the roll 16 of the first sheet. The size of the substrate 18 means the diameter of the circumscribed circle of the substrate 18 .
The size of the substrate 18 is preferably larger than the roll 16 of the first sheet by 1 mm or more, more preferably by 5 mm or more. Although the upper limit is not particularly limited, it is often 600 mm or less.

Flange member 14 has an insert 20 that is positioned on substrate 18 . The insertion portion 20 is a member extending along the normal direction of the substrate 18 .
Although the length along the extending direction of the insertion portion 20 is not particularly limited, it is preferably 2 to 100 mm, more preferably 20 to 30 mm.

Although the insertion portion 20 shown in FIGS. 2 and 3 has a cylindrical shape, it is not limited to this form as long as it can be inserted into the hollow portion of the winding core 12. For example, the shape of the insertion portion may be polygonal. .
The outer diameter of the insertion portion 20 (the outer diameter of the insertion portion 20 ) is preferably smaller than the inner diameter of the core 12 . The outer diameter of the insertion portion 20 is preferably 45-345 mm, more preferably 80-85 mm.

A protruding portion 22 is arranged on the outer peripheral surface of the insertion portion 20 . Although the number of protrusions 22 is three in FIGS. 2 and 3, the number is not particularly limited and may be four or more. The number of protrusions 22 is 3 in that breakage of the microcapsules is further suppressed even when a shock due to dropping is applied (hereinafter, simply referred to as "a point at which the effects of the present invention are more excellent"). 1 or more is preferable, and 4 or more is more preferable. The upper limit is not particularly limited, and is often 100 or less.

As shown in FIG. 3, the three protrusions 22 are arranged on the outer peripheral surface of the insertion portion 20 at regular intervals. The arrangement positions of the projections are not limited to the embodiment shown in FIG. 3, but when there are a plurality of projections, it is preferable that the plurality of projections be arranged at equal intervals on the outer peripheral surface of the insertion portion.
As shown in FIG. 3, the three protrusions 22 are arranged so as to contact the substrate 18 . The relationship between the distances between the protrusions and the substrate is not limited to the embodiment shown in FIG. 3, but it is preferable that the distances between the plurality of protrusions and the substrate are the same. In other words, it is preferable that the distance between the projection and the substrate be the same for each projection.

2 and 3, the shape of the protrusion 22 is rectangular, but the shape is not particularly limited.
The height of the protrusion 22 (the height from the outer peripheral surface of the insertion portion 20) is not particularly limited, and when the insertion portion 20 is inserted into the hollow portion of the core 12, the protrusion is formed on the inner peripheral surface of the core 12. There is no particular limitation as long as the height is such that the portion 22 can come into contact with it. Among them, 0.1 to 5 mm is preferable, 0.5 to 2 mm is more preferable, and 0.5 to 1.5 mm is even more preferable.
The height of the protrusion may be constant or may vary depending on the position. For example, in the point that the effect of the present invention is more excellent, the height of the protrusion may be lowered toward the end of the protrusion in the direction orthogonal to the extending direction of the protrusion.

Although the width in the direction orthogonal to the extending direction of the protrusion 22 is not particularly limited, it is preferably 1 to 25 mm, more preferably 5 to 10 mm.

2 and 3. For example, as shown in FIG. 4, a hole 40 may be provided in a substrate 180 included in the flange member 140. As shown in FIG. By putting a finger through the hole 40, the assembly can be easily carried without dropping. Although eight holes 40 are provided in FIG. 4, the number is not particularly limited and may be one or more.

<Roll of first sheet>
The roll 16 of the first sheet is a wound product made of the first sheet, which is formed by winding the first sheet around a winding core. The first sheet is elongated. Elongated means that the length in the longitudinal direction is longer than the length in the transverse direction.
5 shows a widthwise cross-sectional view of one embodiment of the first sheet, and FIG. 6 represents a top view of the first sheet of FIG.
The first sheet 24 shown in FIGS. 5 and 6 has a support 26 , a cling layer 28 disposed on the support 26 , and a first layer 30 disposed on the cling layer 28 . 5 and 6, a pair of spacers 32 are placed on the first sheet 24. As shown in FIG. As shown in FIGS. 5 and 6, the pair of spacers 32 are spaced apart in the width direction of the first sheet 24 . In such an embodiment, when the first sheet 24 is wound around the core, the presence of the spacer 32 allows the first layer 30 and the supporting portion of the first layer 30 located on the side opposite to the core side. Contact with the body 26 can be suppressed, and breakage of the microcapsules in the first layer 30 can be further suppressed. Therefore, the assembly preferably further includes a pair of spacers arranged between the first sheets of the roll of first sheets and spaced apart in the width direction of the first sheets.
Although the first sheet 24 shown in FIGS. 5 and 6 includes the adhesion layer 28, the present invention is not limited to this embodiment, and the first sheet may not include the adhesion layer.
Also, although the spacers 32 were arranged on the first sheet 24 shown in FIGS. 5 and 6 above, the present invention is not limited to this form, and the assembly need not include spacers.

In addition, the rigidity in the width direction of the first sheet is 150 mN or more. Among them, 153 mN or more is preferable, 165 mN or more is more preferable, 170 mN or more is even more preferable, and 175 mN or more is particularly preferable in that the effects of the present invention are more excellent. When the stiffness in the width direction of the first sheet is 165 mN or more, the microcapsules break even in the first sheet having the first layer containing fragile microcapsules that corresponds to the slight pressure that develops color at 0.2 MPa or less. Hateful. When the stiffness in the width direction of the first sheet is 175 mN or more, even the first sheet having the first layer containing fragile microcapsules corresponding to ultra-low pressure that develops color at 0.05 MPa or less Microcapsules is hard to break. Although the upper limit is not particularly limited, it is often 500 mN or less.
Although the rigidity in the longitudinal direction of the first sheet is not particularly limited, it is preferably 180 mN or less, more preferably 170 mN or less, from the viewpoint that the effects of the present invention are more excellent. Although the lower limit is not particularly limited, it is preferably 100 mN or more, more preferably 130 mN or more, from the viewpoint of manufacturing suitability.

In particular, the rigidity in the width direction of the first sheet is preferably greater than the rigidity in the longitudinal direction of the first sheet, in order to obtain a more excellent effect of the present invention.
The ratio of the stiffness in the width direction of the first sheet to the stiffness in the longitudinal direction of the first sheet (stiffness in the width direction/stiffness in the longitudinal direction) is not particularly limited, and is often 0.90 or more. 1.00 or more is preferable, 1.20 or more is more preferable, and 1.22 or more is still more preferable, because the is more excellent. Although the upper limit is not particularly limited, it is often 1.50 or less, more often 1.40 or less.

The method for measuring the stiffness is as follows.
A test piece of 200 mm in the longitudinal direction (longitudinal direction) and 15 mm in the width direction (horizontal direction) is cut out from the first sheet, and a LOOP STIFFNESS TESTER (manufactured by Toyo Seiki Seisakusho) is used to measure the longitudinal direction and the width direction of the cut test piece. Measure stiffness. Measurement conditions are a clamp interval distance of 100 mm, a loop length of 85 mm, and a compression speed of 3.3 mm/sec. The above measurements are performed on two test pieces, the average value of the longitudinal stiffness obtained from the two test pieces is taken as the longitudinal stiffness of the first sheet, and the average of the width direction stiffness obtained from the two test pieces. The value is taken as the widthwise stiffness of the first sheet. In addition, when measuring the stiffness in the longitudinal direction of the first sheet, a test piece cut out so that the longitudinal direction of the test piece is along the longitudinal direction of the first sheet is used, and the stiffness in the width direction of the first sheet is measured. When measuring, a test piece cut out so that the longitudinal direction of the test piece is along the width direction of the first sheet is used.

The rigidity in the width direction and the longitudinal direction of the first sheet can be appropriately adjusted depending on the type of members constituting the first sheet, the manufacturing method of the first sheet, and the like. For example, when the first sheet includes an adhesion layer, the thickness and number of layers of the adhesion layer, the presence or absence of particles in the adhesion layer, the type of particles, the hardness of the particles, the size of the particles, and the amount of the particles are adjusted. can adjust the rigidity of the first sheet. In addition to the above, the rigidity of the first sheet can be adjusted by adjusting the presence or absence of particles in the resin base material, the type of particles, the hardness of the particles, the size of the particles, and the amount of the particles. Further, the stiffness of the first sheet can be adjusted by adjusting the procedure of the stretching process when manufacturing the first sheet. Furthermore, by adjusting the type of resin base material to be used and manufacturing conditions, the rigidity of the resin base material can be adjusted, and as a result, the rigidity of the first sheet can be adjusted.

Each member (resin base material, adhesion layer, first layer, spacer) will be described in detail below.

(Resin base material)
The first sheet includes an elongated resin base material. The resin base material is a member for supporting the first layer.
A long resin substrate means a resin substrate whose length in the longitudinal direction is longer than the length in the width direction.
Although the width of the resin substrate is not particularly limited, it is often 50 to 1500 mm, preferably 50 to 500 mm.

The resin base material is not particularly limited as long as the first sheet satisfies a predetermined stiffness characteristic, and may be a polyester film such as polyethylene terephthalate film, a cellulose derivative film such as cellulose triacetate film, or a polyolefin film such as polypropylene or polyethylene. , as well as polystyrene films.

Although the thickness of the resin substrate is not particularly limited, it is preferably 10 to 200 μm from the point of view that the effects of the present invention are more excellent.
The resin substrate preferably contains particles in order to make the width direction rigidity of the first sheet 150 mN or more and to make the roll-shaped sheet conveyability good.
Particles include calcium carbonate particles, calcium phosphate particles, silica particles, crystalline glass filler particles, kaolin particles, talc particles, titanium dioxide particles, alumina particles, silica-alumina composite oxide particles, barium sulfate particles, and calcium fluoride particles. , lithium fluoride particles, zeolite particles, molybdenum sulfide particles, and inorganic particles such as mica particles; polystyrene particles, acrylic resin particles, methyl methacrylate particles, benzoguanamine-formaldehyde condensate particles, melamine-formaldehyde condensate particles, and and organic particles such as polytetrafluoroethylene particles.

The resin base material is appropriately selected so that the first sheet exhibits a predetermined stiffness.
Further, the rigidity in the longitudinal direction and the width direction of the resin substrate can be adjusted by controlling manufacturing conditions when manufacturing the resin substrate by a known method (extrusion molding).
The method for producing the resin substrate may include a step of stretching (for example, biaxially stretching) an unstretched film. Moreover, the method for manufacturing the resin base material may have a heat setting step and a heat relaxation step. Moreover, as a method for producing a resin base material, the methods described in paragraphs 0063 to 0125 of JP-A-2011-208125 can be applied.
As one aspect, the resin base material in the present invention preferably does not contain coarse particles, foreign matter, defects, precipitates, and the like. The number of coarse particles with a diameter of 5 μm or more, foreign matters and defects is preferably 50/10 mm ² or less, more preferably 10/10 mm ² or less.

(Adhesion layer)
The adhesion layer is a layer for improving adhesion between the resin substrate and the first layer.
From the point of view that the effect of the present invention is more excellent, the adhesion layer is preferably a resin layer containing a resin, the capsule wall material of the microcapsules is composed of a resin, and the adhesion layer is a resin layer containing a resin. is preferred. In particular, when the binder contained in the first layer is small, the microcapsules may aggregate together when the composition having microcapsules is applied and dried. When the adhesion layer is a resin layer, as shown in FIG. 7, the microcapsules 34 of the first layer 30 interact with the adhesion layer 28 on the resin substrate 26, thereby suppressing aggregation of the microcapsules 34. Since the microcapsules 34 can be stably dispersed on the adhesion layer 28, the color graininess is improved when the pressure is measured.
Materials constituting the adhesion layer are not particularly limited, but examples include styrene-butadiene resin, styrene (meth)acrylic resin, (meth)acrylic resin, olefin resin, urethane resin, polyester resin, and polyvinyl alcohol resin. Among them, styrene-butadiene resin, styrene (meth)acrylic resin, or (meth)acrylic resin is more preferable because the adhesiveness between the resin substrate and the first layer is more excellent.

Among others, the adhesive layer preferably contains a resin having a repeating unit derived from styrene or a derivative thereof, from the viewpoint that the effects of the present invention are more excellent. In particular, when the material of the capsule wall of the microcapsules has an aromatic structure, if the adhesion layer has an aromatic structure, the color-developing graininess is further improved.
The resin having repeating units derived from styrene or its derivatives may contain repeating units other than repeating units derived from styrene or its derivatives.
The content of repeating units derived from styrene or its derivatives in the resin having repeating units derived from styrene or its derivatives is not particularly limited, but is preferably 5 to 100% by mass based on all repeating units.
A styrene derivative means a compound in which a substituent (for example, an alkyl group, an alkoxy group, a carboxyl group, a halogen atom) is substituted at the alpha, ortho, meta or para position of styrene.

Although the thickness of the adhesion layer is not particularly limited, the lower limit is often 0.01 μm or more, and 0.04 μm or more is preferable in that the effects of the present invention are more excellent. The upper limit is often 5 μm or less, preferably 3 μm or less from the viewpoint of more excellent effects of the present invention, and more preferably 2.0 μm or less from the viewpoint of superior coloring graininess when used as a pressure measurement sheet.
The adhesion layer may have a single layer structure or a multilayer structure. When the adhesion layer has a multi-layer structure, the total thickness of the adhesion layer is preferably within the above range.
Also, the adhesion layer may contain other materials than the resin described above. Other materials include, for example, inorganic particles and organic particles. Examples of inorganic particles and organic particles include the same particles that the resin substrate may contain. The particles may be particles having antistatic properties. Also, a plurality of types of particles may be used, and may be contained in both the resin substrate and the adhesion layer.
At least one of the resin base material and the adhesion layer preferably contains particles from the viewpoint that the effects of the present invention are more excellent. By including particles in at least one of the resin base material and the adhesion layer, it is easy to adjust the stiffness in the width direction of the first sheet to 150 mN or more.
From the viewpoint of adjusting the stiffness in the width direction of the first sheet to 150 mN or more, the particle size of the particles contained in either the resin base material or the adhesion layer is preferably large. Specifically, the proportion of inorganic particles with a particle size of 1 μm or more in the total inorganic particles is preferably 50% by volume or more, and more preferably 50% by volume or more of inorganic particles with a diameter of 10 μm or more.
When either the resin base material or the adhesion layer contains inorganic particles and a resin, the ratio of inorganic particles with a particle size of 1 μm or more to the total inorganic particles and the ratio of inorganic particles with a particle size of 10 μm or more are determined as follows. demand.
By baking the resin substrate (the resin substrate and the adhesion layer when it has an adhesion layer, the same shall apply hereinafter), at least part of the resin is decomposed and removed from the resin substrate to leave the inorganic particles. The remaining inorganic particles are dispersed in ethanol. For the inorganic particles contained in the resulting dispersion, using a laser diffraction particle size distribution analyzer (e.g., Mastersizer 2000 manufactured by Malvern, laser diffraction/scattering particle size distribution analyzer LA-920 manufactured by Horiba, Ltd.), A volume-based particle size distribution is determined by a wet method. From the obtained particle size distribution, the ratio (volume %) of inorganic particles having a particle size of 1 μm or more to the total inorganic particles is determined.

The method of forming the adhesion layer is not particularly limited, and for example, a method of applying an adhesion layer-forming composition to a resin substrate, and a method of co-extrusion of an adhesion layer-forming material and a resin substrate-forming material. is mentioned.
In addition, as a method for forming the adhesion layer, a method of applying an adhesion layer-forming composition to the surface of a biaxially stretched resin base material, and a method of applying a composition for forming an adhesion layer to the surface of a resin substrate that has been biaxially stretched, and a resin stretched in a first direction (for example, MD: Machine Direction) A composition for forming an adhesion layer is applied to the surface of the base material, and then the coated product of the composition for forming an adhesion layer is moved along the surface of the resin base material in a second direction perpendicular to the first direction (e.g., TD: Transverse A method of stretching together with a resin base material in Direction) can also be mentioned.

(first layer)
The first layer contains microcapsules encapsulating a color former.
First, the material constituting the microcapsules will be described in detail below.

A microcapsule generally has a core portion and a capsule wall for enclosing a core material forming the core portion (something to be encapsulated (also referred to as an encapsulation component)).
In the present invention, the microcapsules enclose a coloring agent as a core material (encapsulation component). Since the color former is enclosed in the microcapsules, the color former can exist stably until the microcapsules are destroyed by pressure.

A microcapsule has a capsule wall that encloses a core material.
Examples of the material (wall material) for the capsule walls of the microcapsules include known resins conventionally used as wall materials for microcapsules containing color formers in pressure-sensitive copying paper or thermosensitive recording paper applications. Specific examples of the resin include polyurethane, polyurea, polyurethaneurea, melamine-formaldehyde resin, and gelatin.
Among them, the capsule wall of the microcapsules preferably contains at least one resin selected from the group consisting of polyurethane urea, polyurethane, and polyurea, from the viewpoint that the effect of the present invention is more excellent.

Preferably, the capsule wall of the microcapsules is substantially composed of resin. Being substantially composed of a resin means that the resin content is 90% by mass or more, preferably 100% by mass, relative to the total mass of the capsule wall. In other words, the capsule wall of the microcapsules is preferably made of resin.
Note that polyurethane is a polymer having a plurality of urethane bonds, and is preferably a reaction product formed from raw materials containing a polyol and a polyisocyanate.
Polyurea is a polymer having multiple urea bonds, and is preferably a reaction product formed from raw materials containing polyamine and polyisocyanate. It should be noted that polyurea can be synthesized using polyisocyanate without using polyamine by utilizing the fact that a part of polyisocyanate reacts with water to form polyamine.
Polyurethane urea is a polymer having urethane bonds and urea bonds, and is preferably a reaction product formed from raw materials containing polyol, polyamine and polyisocyanate. Incidentally, when the polyol and the polyisocyanate are reacted, part of the polyisocyanate may react with water to form a polyamine, resulting in a polyurethane urea.
Melamine-formaldehyde resins are also preferably reaction products formed from the polycondensation of melamine and formaldehyde.

The polyisocyanate is a compound having two or more isocyanate groups, and includes aromatic polyisocyanate and aliphatic polyisocyanate. The polyisocyanate may be, for example, an adduct (adduct) of a polyol such as trimethylolpropane and a bifunctional polyisocyanate.
In addition, the above-mentioned polyol is a compound having two or more hydroxyl groups. polyols.), polyvinyl alcohols, polyether-based polyols, polyester-based polyols, polylactone-based polyols, castor oil-based polyols, polyolefin-based polyols, and hydroxyl group-containing amine-based compounds (e.g., aminoalcohols). Examples thereof include N,N,N',N'-tetrakis[2-hydroxypropyl]ethylenediamine, which is a propylene oxide or ethylene oxide adduct of an amino compound such as ethylenediamine.
Further, the polyamine is a compound having two or more amino groups (primary amino group or secondary amino group), and examples thereof include diethylenetriamine, triethylenetetramine, 1,3-propylenediamine, and hexa Aliphatic polyamines such as methylenediamine; epoxy compound adducts of aliphatic polyamines; alicyclic polyamines such as piperazine; 3,9-bis-aminopropyl-2,4,8,10-tetraoxa Heterocyclic diamines such as spiro-(5,5)undecane are included.

Although the glass transition temperature of the capsule wall of the microcapsules is not particularly limited, it is preferably 50 to 160°C, more preferably 80 to 150°C.
The method for measuring the glass transition temperature of the capsule wall is as follows.
Fifty first sheets of 1 cm long×1 cm wide are prepared, all of which are immersed in 10 ml of water and allowed to stand for 24 hours to obtain an aqueous dispersion of microcapsules.
The resulting aqueous dispersion of microcapsules is centrifuged at 15000 rpm for 30 minutes to separate the microcapsules. Ethyl acetate is added to the separated microcapsules and further stirred at 25° C. for 24 hours. After that, the obtained solution is filtered, and the obtained residue is vacuum-dried at 60° C. for 48 hours to obtain microcapsules containing nothing inside (hereinafter also simply referred to as “measurement material”). be done. That is, the capsule wall material of the microcapsules, which is the object of measurement of the glass transition temperature, is obtained.
Next, using a thermogravimetric differential thermal analyzer TG-DTA (apparatus name: DTG-60, Shimadzu Corporation), the thermal decomposition temperature of the obtained measurement material is measured. In addition, the thermal decomposition temperature is the temperature of the measurement material heated from room temperature at a constant heating rate (10 ° C./min) in atmospheric thermogravimetric analysis (TGA), and the mass of the measurement material before heating is The temperature at which the weight is reduced by 5% by mass is defined as the thermal decomposition temperature (°C).
Next, the glass transition temperature of the material to be measured was measured using a differential scanning calorimeter DSC (device name: DSC-60a Plus, Shimadzu Corporation) using a closed pan at a heating rate of 5°C/min to 25°C. °C to (thermal decomposition temperature (°C) -5°C). As the glass transition temperature of the capsule wall of the microcapsules, the value at the time of heating in the second cycle is used.

The average particle diameter of the microcapsules is not particularly limited, but the volume-based median diameter (D50) is preferably 1 to 80 μm, more preferably 5 to 70 μm, and even more preferably 10 to 50 μm.
The volume-based median diameter of microcapsules can be controlled by adjusting microcapsule production conditions and the like.
Here, the volume-based median diameter of the microcapsules is the volume of the particles on the large diameter side and the small diameter side when the total volume of the microcapsules is divided into two by the threshold value of the particle diameter at which the total volume is 50%. It means the diameter that the total is equivalent. That is, the median diameter corresponds to so-called D50.
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 is.

The number average wall thickness of the microcapsules (the number average wall thickness of the capsule walls of the microcapsules) is not particularly limited, but is preferably 0.01 μm or more and 2 μm or less, more preferably 0.02 μm or more and less than 2 μm, and 0.05 μm or more and 1.5 μm or more. 5 μm or less is more preferable.
Incidentally, the microcapsule wall thickness refers to the thickness (μm) of the capsule wall forming the capsule particles of the microcapsules, and the number average wall thickness is the thickness (μm) of the individual capsule walls of the five microcapsules. is obtained by scanning electron microscope (SEM) and averaged. More specifically, a cross-section of the first sheet having the first layer containing microcapsules was prepared, and the cross-section was observed with a SEM at a magnification of 200. After selecting arbitrary 5 microcapsules having a long diameter in the range of 9 to (average particle size of microcapsules) × 1.1, the cross section of each selected microcapsule is observed at 15000 times. The thickness of the capsule wall is determined and the average value is calculated. In addition, the major diameter means the longest diameter when microcapsules are observed.

The ratio (δ/Dm) of the number average wall thickness δ of the microcapsules to the average particle size Dm of the microcapsules is not particularly limited, and is often 0.001 or more. Among them, it is preferable to satisfy the relationship of the formula (1) because the effect of the present invention is more excellent.
Formula (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 formula (1) is satisfied, the color density gradation can be made within a range that is easy to recognize depending on the pressure.

[Color former]
A coloring agent is included in the microcapsules.
A color former is a compound that develops color from a colorless state by contact with a color developer described below. As the color former, an electron-donating dye precursor (precursor of a dye that develops color) is preferred. In other words, an electron-donating colorless dye is preferable as the color former.
As the color former, those known in the application of pressure-sensitive copying paper or thermal recording paper can be used. Examples of color formers include triphenylmethanephthalide-based compounds, fluoran-based compounds, phenothiazine-based compounds, indolylphthalide-based compounds, azaindolylphthalide-based compounds, leuco auramine-based compounds, rhodamine lactam-based compounds, and triphenylmethanephthalide-based compounds. Examples include phenylmethane compounds, diphenylmethane compounds, triazene compounds, spiropyran compounds, and fluorene compounds.
Examples of the above compounds include compounds described in JP-A-5-257272, compounds described in paragraphs 0030 to 0033 of WO 2009/8248, 3′,6′-bis(diethylamino)-2-(4 -nitrophenyl)spiro[isoindole-1,9′-xanthene]-3-one, 6′-(diethylamino)-1′,3′-dimethylfluorane, and 3,3-bis(2-methyl- 1-octyl-3-indolyl)phthalide.

The molecular weight of the coloring agent is not particularly limited, and is preferably 300 or more. Although the upper limit is not particularly limited, 1000 or less is preferable.

[Other ingredients]
The microcapsules may enclose components other than the coloring agent described above.
For example, microcapsules preferably enclose a solvent.
The solvent is not particularly limited, and examples thereof include alkylnaphthalene compounds such as diisopropylnaphthalene, diarylalkane compounds such as 1-phenyl-1-xylylethane, alkylbiphenyl compounds such as isopropylbiphenyl, triarylmethane compounds, and alkylbenzene compounds. , aromatic hydrocarbons such as benzylnaphthalene compounds, diarylalkylene compounds, and arylindane compounds; dibutyl phthalate, and aliphatic hydrocarbons such as isoparaffin; soybean oil, corn oil, cottonseed oil, rapeseed oil, olive oil, Examples include natural animal and vegetable oils such as coconut oil, castor oil, and fish oil, and natural high-boiling fractions such as mineral oil.

When the solvent is encapsulated in the microcapsules, the mass ratio of the solvent and the color former (mass of the solvent/mass of the color former) is preferably in the range of 98/2 to 30/70 from the viewpoint of color development. A range of 97/3 to 40/60 is more preferred.

In addition to the components described above, the microcapsules may optionally contain one or more additives such as ultraviolet absorbers, light stabilizers, antioxidants, waxes, and odor inhibitors.

[Method for producing microcapsules]
The method for producing microcapsules is not particularly limited, and examples thereof include known methods such as an interfacial polymerization method, an internal polymerization method, a phase separation method, an external polymerization method, and a coacervation method. Among them, the interfacial polymerization method is preferable.
In the following, the interfacial polymerization method will be described by taking as an example a method for producing microcapsules having a capsule wall made of polyurea or polyurethaneurea.
As the interfacial polymerization method, a color former, a solvent having a boiling point of 100 ° C. or higher, and a capsule wall material (for example, a raw material containing polyisocyanate and at least one selected from the group consisting of polyols and polyamines. Note that poly When isocyanate and water are reacted to produce a polyamine in the system, the polyol and polyamine may not be used.) is dispersed in an aqueous phase containing an emulsifier to prepare an emulsion. (emulsification step), 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 a microcapsule encapsulating the color former (encapsulation step). Legal is preferred.
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 raw material is not particularly limited, but is from 0.1/99.9. 30/70 is preferred, and 1/99 to 25/75 is more preferred.

Also, the type of emulsifier used in the emulsification step is not particularly limited, and examples thereof include dispersants and surfactants.
Dispersants include, for example, polyvinyl alcohol.

The first layer may contain other components (eg, binder, surfactant) in addition to the microcapsules described above.

Also, the mass (g/m ² ) per unit area of the first layer is not particularly limited, but is preferably 0.5 to 30 g/m ² from the standpoint that the effects of the present invention are more excellent.

(Method of forming the first layer)
A method for forming the first layer is not particularly limited.
For example, a method of applying a first layer forming composition containing microcapsules onto a resin substrate (or onto an adhesion layer) and subjecting the resulting coating film to a heat treatment at a predetermined temperature or higher can be mentioned. .
In addition to the above method, a method of preparing microcapsules separately and coating the first layer forming composition containing the microcapsules on the resin base material (or on the adhesion layer) may also be used.
Below, the aspect which heats above predetermined temperature is explained in full detail.

The composition for forming the first layer preferably contains at least microcapsules and a solvent. The microcapsule dispersion liquid 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, and the coating machine used for application includes, for example, an air knife coater, a rod coater, a bar coater, a curtain coater, a gravure coater, and an extrusion coater. , die coaters, slide bead coaters, and blade coaters.

After applying the composition for forming the first layer onto the resin substrate (or onto the adhesion layer), the obtained coating film is subjected to heat treatment at a predetermined temperature or higher.
As the temperature condition for the heat treatment, an optimum temperature is selected according to the material of the capsule wall of the microcapsules to be used. more preferred. Although the upper limit is not particularly limited, it is often 180° C. or lower, and from the viewpoint of better color density, 140° C. or lower is preferable, and 120° C. or lower is more preferable.
The heating time is not particularly limited, but is preferably 1.0 to 20 minutes, more preferably 3.0 to 10 minutes, from the standpoint of better effects of the present invention and productivity.

In the above, the method of forming the first layer on the resin base material (or on the adhesion layer) was described, but the method is not limited to the above-described embodiment. For example, after forming the first layer on the temporary support, The first layer may be transferred onto the resin substrate.
The temporary support is not particularly limited as long as it is a peelable support.

(spacer)
The material of the spacer is not particularly limited, but rubber foam or elastic foam is preferable. Rubber foams include rubber foams selected from the group consisting of natural rubber, isoprene rubber, styrene rubber, nitrile rubber, butadiene rubber, chloroprene rubber, and urethane rubber. Elastomeric foams include elastomeric foams selected from the group consisting of polyethylene, polypropylene, polystyrene, polyvinyl chloride, and polyvinyl acetate.

Although the thickness of the spacer is not particularly limited, it is preferably thicker than the first layer.
The thickness of the spacer is often from 1 to 10 mm, preferably from 1 to 5 mm, more preferably from 2.5 to 5 mm, from the viewpoint that the effects of the present invention are more excellent.

Although the static friction coefficient of the spacer is not particularly limited, it is preferably 0.1 to 1.0 from the viewpoint that the effect of the present invention is more excellent.
Although the dynamic friction coefficient of the spacer is not particularly limited, it is preferably from 0.1 to 1.0 from the viewpoint that the effects of the present invention are more excellent.

The method of arranging the spacers on the first sheet is not particularly limited, and includes a method using a double-sided tape and a method using an adhesive or pressure-sensitive adhesive.

The arithmetic mean roughness Ra of the first sheet is not particularly limited, and is often 0.1 μm or more, preferably 2.5 to 7.0 μm in terms of better color density. The arithmetic mean roughness Ra of the first sheet is intended to be the arithmetic mean roughness Ra of the surface of the first sheet facing (contacting) the second sheet when using the pressure measurement sheet set. do. When the first layer is positioned on the outermost surface of the first sheet facing the second sheet, the arithmetic mean roughness Ra is the arithmetic mean roughness of the surface of the first layer opposite to the resin substrate side. corresponds to Ra.
In addition, the arithmetic mean roughness Ra (the arithmetic mean roughness Ra of the first sheet and the arithmetic mean roughness Ra of the second sheet described later) in this specification is the arithmetic mean roughness Ra defined in JIS B 0681-6: 2014 Means the average roughness Ra. As a measuring apparatus, a scanning white light interferometer using an optical interference method (specifically, NewView 5020 manufactured by Zygo; objective lens x 50; intermediate lens x 0.5) is used. The measurement mode for measuring the arithmetic mean roughness Ra of the first sheet using the scanning white light interferometer is Stich mode, and the measurement mode for measuring the arithmetic mean roughness Ra of the second sheet is Micro mode. is.

In addition, in the assembly 10 shown in FIGS. 1 to 3, the insertion portion 20 of the flange member 14 is inserted into the hollow portion of the winding core 12 and both are fixed, but the fixing method is not limited to this aspect. .
For example, there is a projection on the outer peripheral surface of the end of the winding core, the flange member has a recess into which the end of the winding core is inserted, the end of the winding core is inserted into the recess, and the projection of the winding core The core and the flange member may be fixed with the portion in contact with the flange member.
Also, a fixing method other than the method of using the protrusion may be used. For example, the winding core and the flange member may be fixed by adhering with an adhesive. Alternatively, the winding core and the flange member may be screwed together.

The assembly of the present invention may be enclosed in a package. It may be a bag, or a container including a container body having an opening and a lid closing the opening.

The material constituting the package is not particularly limited, but examples include resins, more specifically polyolefin resins, polyethylene resins, and polypropylene resins.

The color of the package is not particularly limited, but includes transparent color, brown and black. Among them, brown or black is preferable, and black is more preferable, from the viewpoint of light resistance.

<Second sheet>
The assembly of the present invention may be combined with a second sheet having a second layer containing a developer to form a pressure measuring sheet set.
The second sheet may be treated as an assembly. That is, the sheet set for pressure measurement of the present invention includes a core, a pair of flange members fixed to both ends of the core, and a first layer containing microcapsules wound around the core and containing a coloring agent. a first assembly having: a winding core; a pair of flange members fixed to opposite ends of the winding core; a second sheet comprising; and a second assembly comprising.

When using the sheet set for pressure measurement, the first sheet and the second sheet are laminated so that the first layer in the first sheet and the second layer in the second sheet face each other. . By applying pressure to the obtained laminate, the microcapsules are broken in the pressurized area, and the color former contained in the microcapsules comes out of the microcapsules and mixes with the color developer in the second layer. A color reaction proceeds between As a result, color development progresses in the pressurized area.

The second sheet has a second layer containing a developer. Among others, the second sheet preferably includes a support and a second layer disposed on the support.
Below, each member is explained in full detail.

(support)
The support is a member for supporting the second layer. If the second layer itself can be handled, the second sheet may not have a support.
The support may be either sheet-like or plate-like.
Examples of the support include resin substrates and synthetic papers, with resin substrates being preferred. Examples of the form of the resin base include the form of the resin base contained in the first sheet described above.
Further, as the support, a mode of a laminate of a resin base material and an adhesion layer, which is described in the first sheet, can also be used. Preferred aspects of the resin base material and the adhesion layer are as described above.
The support in the first sheet and the support in the second sheet may be the same or different.
The support in the second sheet is preferably transparent, and the haze of the support is preferably from 0 to 20%, more preferably from 0 to 10%, because the color development state after pressure measurement is easily visible through the support. preferable.

(Second layer)
The second layer is a layer containing a developer.
A color developer is a compound that does not have a color-developing function by itself, but has the property of causing the color-developing agent to develop color upon contact with the color-developing agent. Electron-accepting compounds are preferred as color developers.
The developer includes inorganic compounds and organic compounds, and inorganic compounds and organic compounds described in paragraphs 0055 to 0056 of WO 2009/008248 are preferred. Acidic clay, activated clay, or a metal salt of an aromatic carboxylic acid is preferred in that the color density and the image quality after color development are more excellent.

Although the content of the developer in the second layer is not particularly limited, it is preferably 20 to 95% by mass, more preferably 30 to 90% by mass, based on the total mass of the second layer in terms of better color density. .

Although the content of the developer in the second layer is not particularly limited, it is preferably 0.1 to 30 g/m ² . When the developer is an inorganic compound, the content of the developer is preferably 3 to 20 g/m ² , more preferably 5 to 15 g/m ² . When the developer is an organic compound, the content of the developer is preferably 0.1 to 5 g/m ² , more preferably 0.2 to 3 g/m ² .

The second layer may contain components other than the developer described above.
Other ingredients include, for example, polymeric binders, pigments, optical brighteners, defoamers, penetrants, UV absorbers, surfactants, and preservatives.
Polymer binders include, for example, styrene-butadiene copolymer, polyvinyl acetate, polyacrylate, polyvinyl alcohol, polyacrylic acid, maleic anhydride-styrene copolymer, olefin resin, and modified acrylic ester copolymer. , starch, casein, gum arabic, gelatin, carboxymethylcellulose or its salts, and synthetic and natural polymers such as methylcellulose.
Examples of pigments include heavy calcium carbonate, light calcium carbonate, talc, and titanium dioxide.

Although the thickness of the second layer is not particularly limited, it is preferably from 1 to 50 μm, more preferably from 2 to 30 μm, in terms of the effect of the present invention being more excellent.
Also, the mass (g/m ² ) per unit area of the second layer is not particularly limited, but is preferably 0.5 to 30 g/m ² from the standpoint that the effects of the present invention are more excellent.

(Method for forming second layer)
A method for forming the second layer is not particularly limited.
For example, there is a method of applying a composition for forming a second layer containing a color developer onto a support, and subjecting the obtained coating film to a drying treatment, if necessary.
The composition for forming the second layer may be a dispersion liquid in which a color developer is dispersed in water or the like. When the developer is an inorganic compound, the dispersion containing the developer can be prepared by mechanically dispersing the inorganic compound in water. When the developer is an organic compound, it can be prepared by mechanically dispersing the organic compound in water or by dissolving it 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, and a method using a coating machine used for applying the composition for forming the first layer described above may be used.

After applying the composition for forming the second layer onto the support, the coating film may be subjected to a drying treatment, if necessary. The drying treatment includes heat treatment.

In the above, the method of forming the second layer on the support was described, but the method is not limited to the above-described mode. For example, after forming the second layer on the temporary support, peeling off the temporary support, A second sheet of a second layer may be formed.
The temporary support is not particularly limited as long as it is a peelable support.

(Other members)
The second sheet may have members other than the support and the second layer described above.
For example, the second sheet may have an adhesion layer between the support and the second layer for enhancing adhesion between the two.
Examples of the form of the adhesion layer include the form of the adhesion layer that the first sheet described above may have.

As described above, the first sheet and the second sheet are laminated by laminating the first sheet and the second sheet so that the first layer of the first sheet and the second layer of the second sheet face each other. It is used by taking a body and pressing it against the laminate.
That is, the first sheet corresponds to a sheet used for measuring pressure together with the second sheet.

The arithmetic mean roughness Ra of the second sheet is preferably 1.2 μm or less from the viewpoint of better color density. The arithmetic mean roughness Ra of the second sheet is intended to be the arithmetic mean roughness Ra of the surface of the second sheet facing (contacting) the first sheet when using the pressure measurement sheet set. do. When the second layer is positioned on the outermost surface of the second sheet facing the first sheet, the arithmetic average roughness Ra is the arithmetic average roughness Ra of the surface of the second layer opposite to the support side. correspond to

The present invention will be described in more detail based on examples below. The materials, amounts used, proportions, processing details, processing procedures, etc. shown in the following examples can be changed as appropriate without departing from the gist 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>
A long polyethylene terephthalate film (PET film) (width 450 mm) having a thickness of 75 μm and having both surfaces subjected to corona discharge treatment after being biaxially stretched was prepared. Next, on one surface of the obtained PET film, an adhesive layer-forming composition A, which will be described later, was applied using a bar coater and dried to form an adhesive layer A having a thickness of 0.45 μm.

The composition of the adhesive layer-forming composition A is as follows.
The mass of each dispersion is expressed as "parts by mass" when the total mass of the composition is 100 parts by mass.
-Adhesion layer-forming composition A-
・ Styrene / butadiene copolymer latex (styrene: butadiene = 67: 30, product name: LX-407C5, manufactured by Nippon Zeon Co., Ltd., solid content 40% by mass) 14.1 parts by mass 2,4-dichloro-6 -Hydroxy-s-triazine (solid content 8% by mass) 2.5 parts by mass Polystyrene particles (product name: UFN1008, Nippon Zeon Co., Ltd., average particle: 2 μm, solid content 20% by mass) 0.04 parts by mass・ Distilled water 83.4 parts by mass

Subsequently, a composition B for forming an adhesion layer having the following composition was applied on the adhesion layer A by a bar coater and dried to form an adhesion layer B having a thickness of 0.1 μm.
- Adhesion layer-forming composition B-
・ 10 parts of 10.4% aqueous solution of gelatin (761 gelatin, manufactured by Nitta Gelatin Co., Ltd., solid content 100%) ・ 0.04 parts of 3.5% methanol solution of 1,2-benzothiazolin-3-one ・0.67 parts of 3% aqueous solution of hydroxypropyl methylcellulose (Metolose TC5R, manufactured by Shin-Etsu Chemical Co., Ltd., solid content 100%) 1% aqueous solution of sodium hydroxide (Naroacty CL-95: manufactured by Sanyo Chemical Industries Co., Ltd. , solid content 1%) 0.7 parts Antimony-doped tin oxide dispersion (TDL-S: manufactured by Mitsubishi Materials Corporation, solid content 17%, inorganic particles having antistatic properties) 4.9 parts Distilled water 83 .7 copies

A solution A was obtained by dissolving 3,3-bis(2-methyl-1-octyl-3-indolyl)phthalide (18 parts by mass) as a coloring agent in diarylethane (70 parts by mass). Also, a butylene oxide adduct of ethylenediamine (0.4 parts by mass) dissolved in methyl ethyl ketone (1 part by mass) was added to the stirred solution A to obtain a solution B. Furthermore, a trimethylolpropane adduct of tolylene diisocyanate (2 parts by weight) dissolved in methyl ethyl ketone (1 part by weight) was added to the stirred solution B to obtain a solution C.
Next, the above solution C was added to a solution of polyvinyl alcohol (6 parts by mass) dissolved in water (150 parts by mass) to emulsify and disperse. Water (300 parts by mass) was added to the emulsion after emulsification and dispersion, heated to 70° C. with stirring, stirred for 1 hour, and then cooled to prepare a microcapsule liquid containing microcapsules encapsulating a color former. . The average particle size of the obtained microcapsules was 20 μm. The prepared microcapsule liquid was used as a color former-containing microcapsule liquid (A).

After mixing water (75 parts by mass), sodium polyacrylate (5 parts by mass), and calcium carbonate (100 parts by mass) and dispersing with a sand mill, SBR latex (solid content equivalent to 15 parts by mass), carboxymethyl cellulose 1 An aqueous solution (15 parts by mass) by mass and a 25% by mass aqueous solution of sodium dodecylbenzenesulfonate (1 part by mass) are added and mixed, and water is added to make the solid content concentration 41.5% by mass. A layer-forming composition was prepared.

Next, on the adhesion layer B of the support 1, protective ear layers are formed at both ends in the width direction of the support 1, and the first layer is formed between the protective ear layers. The color former-encapsulating microcapsule liquid (A) is applied to the support 1 having a width of 450 mm on the adhesion layer B side, and then the protective ear layer-forming composition is applied so as to be in contact with both ends in the width direction. After drying, a sheet was obtained. In the resulting sheet, the width of the first layer was 400 mm and the width of the protective ear layer was 25 mm on one side (50 mm on both sides).
Next, the central portion of the sheet was cut to a width of 360 mm using a processing machine so as to remove the protective selvage layers positioned at both ends of the obtained sheet in the width direction, and the sheet was placed on the support 1 and the support 1. A long first sheet having the first layer was obtained. The double-faced tape described below was attached to both edges of the obtained first sheet in the width direction, and the following cushions (spacers) were attached. As shown in FIGS. A first sheet was produced.
Next, a hollow cylindrical winding core, which will be described later, and a flange member, which will be described later, were prepared. The flange member had a base plate and a cylindrical insertion portion arranged on the base plate, and a protrusion was arranged on the surface of the insertion portion (see FIGS. 2 and 3). The insertion portion of the flange member was inserted into the hollow portion of the winding core, and the flange members were fixed to both ends of the winding core to produce a winding core with flange members.
Next, the first sheet on which the spacers are arranged is wound around the winding core of the winding core with the flange member, and the cross-sectional diameter of both ends (the outer diameter of the first sheet roll) is 170 mm. was made.

-spacer-
Material: Neoprene foam rubber (manufactured by Tokiwa Rubber Co., Ltd.), width: 15 mm, thickness: 5 mm, static friction coefficient: 0.63, dynamic friction coefficient: 0.62
-Double-sided tape-
Japanese paper + acrylic adhesive (manufactured by Sekisui Chemical Co., Ltd., double tack tape #595), width: 10 mm
- winding core -
Made of paper (impregnated with resin), length: 390 mm, inner diameter of hollow part: 76 mm
-Flange member (see Fig. 2)-
Material: Polypropylene (PP), Substrate shape: Octagonal, Substrate size: 210mm, Diameter of circumscribed circle diameter): 77.5 mm, number of protrusions: 8 evenly spaced, protrusion height: 1.3 mm

<Examples 2 to 15, Comparative Example 1>
Assemblies 2 to 15 of Examples 2 to 15 and assembly C1 of Comparative Example 1 were produced according to the same procedure as in Example 1, except that various requirements shown in Table 1, which will be described later, were changed.
Supports 2 to 14 described in the table were prepared by the following method.

(Preparation of support 2)
Adhesion layer-forming composition A was prepared in the same manner as for adhesion layer-forming composition A, except that the styrene/butadiene copolymer latex was replaced with a styrene acrylic copolymer (AS-563A, manufactured by Daicel Finechem Co., Ltd., solid content: 27.5% by mass). An adhesive layer-forming composition C was prepared.
A support 2 was obtained in the same manner as the support 1, except that the adhesion layer-forming composition A was changed to the adhesion layer-forming composition C and the thickness was changed.
(Preparation of supports 3, 5 to 14)
Supports 3 and 5 to 14 were obtained in the same manner as Support 1, except that various requirements shown in Table 1, which will be described later, were changed.
(Preparation of support 4)
The adhesion layer-forming composition C was applied to both surfaces of a long polyethylene terephthalate film (PET film) having a thickness of 75 μm that had been uniaxially stretched in the longitudinal direction, and dried. Next, it was stretched in the width direction, heat-set and heat-relaxed, and a support 4 was obtained.

<Production of second sheet>
Activated clay (BYK-chemie, FURACOLOR SR) (100 parts by mass), sodium hexametaphosphate (Nippon Kagaku Kogyo, sodium hexametaphosphate) (0.5 parts by mass), 10% aqueous sodium hydroxide solution (15 parts by mass), Then, water (240 parts by mass) was added, and to the resulting dispersion, an olefin resin (Arakawa Chemical Industries, Polymaron 482) (30 parts by mass), a modified acrylic acid ester copolymer (Nippon Zeon, Nippol LX814) ( 35 parts by mass), 1% aqueous solution (80 parts by mass) of carboxymethylcellulose sodium (Daiichi Kogyo Seiyaku Co., Ltd., Cellogen EP), 15% aqueous solution (18 parts by mass) of sodium alkylbenzenesulfonate (Daiichi Kogyo Seiyaku Co., Ltd., Neogen T), 1% aqueous solution (20 parts by mass) of polyoxyethylene polyoxypropylene lauryl ether (Daiichi Kogyo Seiyaku, Noigen LP-70), sodium - bis (3,3,4,4,5,5,6,6) ,6-nonafluorohexyl)-2-sulfinatoxysuccinate (Fuji Film, W-AHE) was mixed with a 1% aqueous solution (20 parts by mass) to prepare a composition for forming a second layer containing a clay substance. Obtained.
The composition for forming the second layer was applied onto the support 1 so that the solid content coating amount was 7 g/m ² . Then, the obtained coating film was dried to form a second layer and obtain a second sheet. The haze of Support 1 was 10% or less.

<Measurement>
(stiffness)
A test piece of 200 mm in the longitudinal direction (longitudinal direction) and 15 mm in the width direction (horizontal direction) was cut out from the first sheet produced in each example and comparative example, and a LOOP STIFFNESS TESTER (manufactured by Toyo Seiki Seisakusho) was used to test the first sheet. The stiffness in the longitudinal direction and width direction of one sheet was measured. The measurement conditions were a clamp interval distance of 100 mm, a loop length of 85 mm, and a compression speed of 3.3 mm/sec. The above measurements are performed on two test pieces, the average value of the longitudinal stiffness obtained from the two test pieces is taken as the longitudinal stiffness of the first sheet, and the average of the width direction stiffness obtained from the two test pieces. The value was taken as the stiffness in the width direction of the first sheet. In addition, when measuring the stiffness in the longitudinal direction of the first sheet, a test piece cut out so that the longitudinal direction of the test piece is along the longitudinal direction of the first sheet is used, and the stiffness in the width direction of the first sheet is measured. When measuring, a test piece cut out so that the longitudinal direction of the test piece was along the width direction of the first sheet was used.

<Evaluation>
(Drop test)
Based on distribution condition level I of JIS Z0202, each assembly was subjected to 1 corner, 3 edges, and 6 faces, and evaluated according to the following criteria. Table 1 shows the results.
A: No trace of destruction of microcapsules was observed.
B: Traces of destruction of microcapsules were slightly observed (actually usable level).
C: A large number of traces of destruction of microcapsules were observed.

(Color development graininess)
The first sheet included in each assembly and the second sheet cut to a size of 5 cm long x 5 cm wide were arranged so that the surface of the first layer of the first sheet and the surface of the second layer of the second sheet faced each other. superimposed on each other. Both superimposed sheets were sandwiched between two smooth-surfaced glass plates and placed on a desk, and a pressure of 0.2 MPa was applied by placing a weight on the glass plates to cause color development. Thereafter, the colored surface of the colored second sheet was visually observed from the side of the support (PET sheet) via the support, and evaluated according to the following evaluation criteria. The sample of Comparative Example 1 was not evaluated because the capsule was destroyed in the drop test. Table 1 shows the evaluation results.
A: Very little graininess on the colored surface.
B: There is a slight graininess on the colored surface, but there is no practical problem.
C: Clearly large graininess on the colored surface.

As shown in Table 1, the desired effect was obtained when using the assembly of the present invention.
Above all, it was confirmed from a comparison between Example 4 and other examples that a more excellent effect was obtained when the thickness of the spacer was 2.5 μm or more.
Moreover, it was confirmed from the comparison between Examples 8, 10 and 15 and other Examples that a more excellent effect was obtained when the stiffness in the width direction (horizontal direction) of the first sheet was 165 mN or more.
In addition, it was confirmed from a comparison between Examples 10 and 15 and other examples that a superior effect was obtained when the ratio of stiffness in the width direction to stiffness in the longitudinal direction was 1.00 or more.
Moreover, it was confirmed from a comparison between Example 12 and other examples that when the thickness of the adhesion layer was 2.0 μm or less, excellent effects were obtained due to the color development graininess.
Moreover, it was confirmed from a comparison between Example 14 and other examples that when there is an adhesion layer, more excellent effects can be obtained, and that the color development graininess is excellent.

<Example 16>
Synthetic isoparaffin (Idemitsu Kosan Co., Ltd., IP Solvent 1620) (15 parts by mass), N,N,N',N'-tetrakis(2-hydroxypropyl)ethylenediamine (manufactured by Co., Ltd.) dissolved in ethyl acetate (3 parts by mass) ) Adeka, Adeka Polyether EDP-300) (0.4 parts by mass) is added to stirring 1-phenyl-1-xylylethane (Nippon Oil Co., Ltd., Hysol SAS296) (78 parts by mass) to form a solution got a D.
Furthermore, a trimethylolpropane adduct of tolylene diisocyanate (DIC Corporation, Barnock D-750) (3 parts by mass) dissolved in ethyl acetate (7 parts by mass) was added to the stirring solution D to obtain a solution. got E.
Then, the above solution E was added to a solution of polyvinyl alcohol (PVA-205, Kuraray Co., Ltd.) (69 parts by mass) dissolved in water (140 parts by mass) to emulsify and disperse. Water (340 parts by mass) was added to the emulsion after emulsification and dispersion, and the mixture was heated to 70° C. with stirring, stirred for 1 hour, and then cooled. Further, water was added to adjust the concentration to obtain a microcapsule liquid (B) not encapsulating a coloring agent having a solid content concentration of 19.6%.

Color former-encapsulating microcapsule liquid (A) obtained above (18 parts by mass), color former-free microcapsule liquid (B) (2 parts by mass), water (63 parts by mass), carboxymethyl cellulose Na (Daiichi Kogyo Seiyaku Co., Ltd., Cellogen 5A) 10% aqueous solution (1.8 parts by mass), 1% aqueous solution (30 parts by mass) of carboxymethyl cellulose Na (Daiichi Kogyo Seiyaku Co., Ltd., Celogen EP), sodium alkylbenzene sulfonate (No. Ichi Kogyo Seiyaku Co., Ltd., Neogen T) 15% aqueous solution (0.3 parts by mass) and Neugen LP70 (Daiichi Kogyo Seiyaku Co., Ltd.) 1% aqueous solution (0.8 parts by mass) are mixed, A specific composition was obtained by stirring for 2 hours.

An assembly 16 was produced in the same manner as in Example 1 above, except that the specific composition was used instead of the color former-encapsulating microcapsule liquid (A) and the PET film used was changed.

<Examples 17 to 22, Comparative Example 2>
Assemblies 17 to 22 of Examples 17 to 22 and assembly C2 of Comparative Example 2 were produced according to the same procedure as in Example 16, except that various requirements shown in Table 2, which will be described later, were changed.

Using the assemblies 16 to 22 and the assembly C2 obtained above, the above measurements and evaluations were performed. Table 2 summarizes the results.
In addition, in the evaluation of coloring graininess in Examples 16 to 22, the pressure was changed to 0.05 MPa. The color graininess of the sample of Comparative Example 2 was not evaluated because the capsules were destroyed in the drop test.

As shown in Table 2, the desired effect was obtained when using the assembly of the present invention.
Moreover, it was confirmed from the comparison of Examples 16 to 22 that a more excellent effect can be obtained when the rigidity in the width direction is 175 mN or more.
In addition, it was confirmed from the comparison between Example 22 and other examples that when there is an adhesion layer, more excellent effects can be obtained, and that the color development graininess is excellent.

REFERENCE SIGNS LIST 10 Assembly 12 Winding core 14 Flange member 16 First sheet roll 18 Substrate 20 Insertion portion 22 Protruding portion 24 First sheet 26 Resin substrate 28 Adhesion layer 30 First layer 32 Spacer 34 Microcapsule

Claims (13)

winding core and
An assembly comprising a roll of the first sheet formed by winding a long first sheet around the winding core,
The first sheet has an elongated resin substrate and a first layer containing microcapsules containing a color former disposed on the resin substrate,
The assembly, wherein the stiffness in the width direction of the first sheet is 150 mN or more. 2. The assembly of claim 1, wherein the widthwise stiffness of the first sheet is greater than the longitudinal stiffness of the first sheet. 3. The assembly of claim 2, wherein said first sheet has a longitudinal stiffness of 180 mN or less. The assembly according to any one of claims 1 to 3, wherein the stiffness in the width direction of the first sheet is 165 mN or more. 5. The method according to any one of claims 1 to 4, further comprising a pair of spacers disposed between the first sheets of the roll of the first sheet and spaced apart in the width direction of the first sheet. assembly. The assembly according to claim 5, wherein said spacer has a thickness of 1-5 mm. The assembly according to any one of claims 1 to 6, wherein said first sheet further has an adhesion layer between said resin base material and said first layer. 8. The assembly of claim 7, wherein said adhesion layer comprises a resin having repeating units derived from styrene or derivatives thereof. The assembly according to claim 7 or 8, wherein the adhesive layer has a thickness of 0.01 to 2.0 µm. An assembly according to any preceding claim, further comprising a pair of flange members secured to opposite ends of the winding core. an assembly according to any one of claims 1 to 10;
and a second sheet having a second layer comprising a developer. a first sheet having an elongated resin substrate and a first layer containing microcapsules containing a coloring agent disposed on the resin substrate;
a second sheet having a second layer containing a color developer, comprising:
The sheet set for pressure measurement, wherein the rigidity in the width direction of the first sheet is 150 mN or more. A sheet having an elongated resin substrate and a first layer containing microcapsules containing a color former arranged on the resin substrate,
The sheet, wherein the stiffness in the width direction of the first sheet is 150 mN or more.

Images