JP7360533B2 - Assembly, pressure measurement sheet set - Google Patents

Description

The present invention relates to an assembly and a set of sheets for pressure measurement.

In recent years, as products become more sophisticated and sophisticated, the need to measure pressure distribution tends to increase.
Pressure measurement sheet sets are known for measuring pressure distribution. The pressure measurement sheet set is comprised 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.

Japanese Patent Application Publication No. 2009-173307

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

In view of the above-mentioned circumstances, the present invention provides an assembly having a sheet having a layer containing microcapsules containing a coloring agent wound around a winding core. An object of the present invention is to provide an assembly in which destruction of a capsule is suppressed.
Another object of the present invention is to provide a pressure measurement sheet set.

As a result of intensive study on the above-mentioned problem, the present inventors found that the above-mentioned problem can be solved by the following configuration.

(1) A winding core,
a pair of flange members fixed to both ends of the winding core;
An assembly comprising: a roll of a first sheet formed by winding a long first sheet having a first layer containing microcapsules containing a coloring agent around a winding core;
An assembly in which the fixing strength between the winding core and the flange member is 20N or more.
(2) The winding core has a hollow cylindrical shape,
The flange member has a substrate and an insertion portion that can be inserted into a hollow part of a winding core disposed on the substrate,
The assembly according to (1), wherein the protrusion is arranged on the outer peripheral surface of the insertion portion.
(3) The assembly according to (2), wherein the number of protrusions is three or more.
(4) The inner diameter change rate of the winding core obtained by Test 1 described below is 1.0% or less,
The assembly according to (2) or (3), wherein the wall thickness change rate of the winding core obtained by Test 2 described later is 10.0% or less.
(5) When the flange member is observed from the normal direction of the substrate, the diameter of the circumscribed circle that circumscribes the region consisting of the insertion portion and the protrusion is 0.7 to 2.0 mm larger than the inner diameter of the winding core, (2 ) to (4).
(6) The assembly according to any one of (1) to (5), wherein the outer peripheral surface of the winding core has a surface roughness Ra of 1.0 to 4.0 μm.
(7) The method according to any one of (1) to (6), further comprising 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. assembly.
(8) The assembly according to (7), wherein the spacer has a thickness of 1 to 5 mm.
(9) The assembly according to any one of (1) to (8),
A pressure measurement sheet set comprising: a second sheet having a second layer containing a color developer.

According to the present invention, there is provided an assembly including a sheet having a layer containing microcapsules encapsulating a coloring agent wound around a winding core, and the microcapsules are not destroyed even when subjected to impact due to dropping. A restrained assembly can be provided.
Moreover, according to the present invention, a pressure measurement sheet set can also be provided.

1 is a perspective view of one embodiment of an assembly of the present invention. FIG. It is a perspective view showing one embodiment of a flange member. FIG. 4 is a top view of the flange member of FIG. 3; It is a perspective view showing other embodiments of a flange member. It is a sectional view showing one embodiment of a first sheet. FIG. 6 is a top view of the first sheet of FIG. 5;

The present invention will be explained in detail below.
In addition, in this specification, a numerical range expressed using "~" means a range that includes the numerical values written before and after "~" as a lower limit value and an upper limit value.
In addition, in the numerical ranges described in stages in this specification, the upper limit or lower limit described in a certain numerical range may be replaced with the upper or lower limit of another numerical range described in stages. 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 value shown in the Examples.
The various components described below may be used alone or in combination of two or more. For example, the polyisocyanates described below may be used alone or in combination of two or more.

A feature of the assembly of the present invention is that the fixing strength between the winding core and the flange member is adjusted to a predetermined value or more.
The present inventors discovered that in conventional assemblies, the solid strength between the winding core and the flange member was low, so that the winding core and the flange member were likely to wobble during transportation and handling of the assembly, and microcapsules were It is thought that the layer containing the microcapsules was more susceptible to impact, and as a result, the microcapsules were more likely to be destroyed. On the other hand, in the present invention, the above problem is suppressed by setting the fixing strength to a predetermined value or more.

FIG. 1 is a perspective view of 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, which will be described later, around the winding core 12. and a roll 16 of the first sheet.
FIG. 2 shows a perspective view of the flange member 14 shown in FIG. 1. FIG. 3 shows a top view of the flange member 14. The flange member 14 includes a substrate (flange) 18, an insertion section 20 disposed on the substrate 18, and a protrusion 22 disposed 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 part 20 of the flange member 14 is inserted into the hollow part of the winding core 12, and the projection part 22 of the insertion part 20 comes into contact with the inner peripheral surface of the winding core 12, so that the winding core 12 and the flange The member 14 is fixed.
Each member will be explained in detail below.

<Winding core 12>
The first sheet is wound around the winding core 12 .
Materials for the winding core 12 include plastic, paper, wood, and metal. Among these, paper is preferable as the material for the winding core in that the fixing strength between the winding core and the flange member is 20N or more. Examples of paper include paper tube base paper and resin-impregnated paper. The pulp used as a raw material for paper may be virgin pulp such as chemical pulp and high-yield pulp, or recycled pulp.
Although the size of the winding core 12 is not particularly limited, the outer diameter (outside diameter of the winding core) is preferably 50 to 350 mm, more preferably 85 to 90 mm.
In addition, when a winding core has a shape other than a cylindrical shape, the said outer diameter corresponds to the diameter of the circumscribed circle of a winding core.

The inner diameter of the cylindrical winding core 12 is preferably 45 to 345 mm, more preferably 70 to 85 mm.

It is preferable that the inner diameter and wall thickness (thickness corresponding to the difference between the outer diameter and the inner diameter) of the winding core 12 do not change depending on environmental conditions.
Among these, it is preferable that the inner diameter change rate of the winding core obtained by the following Test 1 is 1.0% or less, and the wall thickness change rate of the winding core obtained by the following Test 2 is 10.0% or less. It is preferable. The lower limits of the inner diameter change rate and wall thickness change rate are not particularly limited, but may be 0%.
Test 1: After the winding core was allowed to stand for 24 hours in an environment of 23°C and 65% RH, the inner diameter of the winding core was measured at four locations to obtain the inner diameter before heating. After standing still for 24 hours in an environment of ℃, the inner diameter of the winding core at the above four locations was measured to obtain the inner diameter after heating, and the inner diameter before heating and after heating obtained at the four locations above. Using each of the inner diameters, the rate of change determined by the following equation (1) at the above four locations is calculated, and the obtained average value is further arithmetic averaged, and the value obtained is defined as the rate of change in the inner diameter.
Formula (1): Rate of change = {|Inner diameter after heating - Inner diameter before heating |/Inner diameter before heating} x 100
Test 2: After leaving the winding core for 24 hours in an environment of 23°C and 65% RH, the wall thickness of the winding core was measured at four locations to obtain the wall thickness before heating. After standing for 24 hours in an environment of 105°C, the wall thickness of the winding core at the above four locations was measured to obtain the wall thickness after heating, and the thickness before heating obtained at the above four locations was measured. Using the wall thickness and the wall thickness after heating, respectively, calculate the rate of change obtained by the following formula (2) at the four locations above, and then calculate the value obtained by further arithmetic averaging the obtained average value. Let it be the wall thickness change rate.
Formula (2): Rate of change = {|Thickness after heating - Thickness before heating | / Thickness before heating} x 100

The surface roughness Ra of the outer circumferential surface of the winding core is not particularly limited, but is often 1.0 to 20 μm, and is preferably 1.0 to 4.0 μm in that it can better prevent damage to the first sheet. .
The above surface roughness Ra is measured using a stylus type surface roughness meter (Handysurf E-35A, manufactured by Tokyo Seimitsu Co., Ltd.) according to ISO97. Measure. The measurement conditions were an evaluation length of 4 mm and a cutoff value of 0.8 mm. The above measurement is carried out three times, and the obtained measurement values are arithmetic averaged to obtain the surface roughness Ra.

Although the winding core 12 has a hollow cylindrical shape in FIG. 1, it is not limited to this shape as long as the first sheet can be wound thereon.
For example, the winding core may have a polygonal column shape. Further, the winding core may be solid.
Further, a cushion layer made of foamed polyethylene or the like may be provided between the winding core and the first sheet.

<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 protrusion 22 in the flange member 14 coming into contact with the inner circumferential surface of the winding core 12.

Materials for the flange member 14 include plastic, paper, wood, and metal. Among these, plastic is preferred. Examples of the plastic include polypropylene, polyethylene, and polyethylene terephthalate, with polypropylene being preferred.
In addition, it is preferable that the insertion part 20 and the protrusion part 22 mentioned later are also comprised with the said material.

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

Flange member 14 has an insert portion 20 disposed on substrate 18 . The insertion portion 20 is a member extending along the normal direction of the substrate 18.
The length along the extending direction of the insertion portion 20 is not particularly limited, but 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 insertion portion may have a polygonal shape. .
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 winding core 12. The outer diameter of the insertion portion 20 is preferably 45 to 345 mm, more preferably 70 to 85 mm.

Note that the normal direction of the substrate 18 is advantageous in that the destruction of the microcapsules is further suppressed even when an impact is applied due to a fall (hereinafter also simply referred to as "a point where the effects of the present invention are more excellent"). When observing the flange member 14 from above, the diameter of the circumscribed circle that circumscribes the region consisting of the insertion portion 20 and the protrusion 22 (hereinafter also simply referred to as the “diameter of the circumscribed circle”) is 0.0% smaller than the inner diameter of the winding core 12. It is preferable that it is larger by .7 to 2.0 mm.
As shown in FIG. 3, the circumscribed circle is a circle that circumscribes the area consisting of the insertion portion 20 and the protrusion 22 when the flange member 14 is observed from the normal direction of the substrate 18; Represented by a dashed line.

A protrusion 22 is arranged on the outer circumferential surface of the insertion portion 20 . In FIGS. 2 and 3, the number of protrusions 22 is three, but the number is not particularly limited and may be four or more. The number of protrusions 22 is preferably three or more, and more preferably four or more, in that the effects of the present invention are more excellent. The upper limit is not particularly limited, and is often 100 or less.

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

In FIGS. 2 and 3, the shape of the protrusion 22 is rectangular, but the shape is not particularly limited.
The height of the protrusion 22 (height from the outer peripheral surface of the insertion part 20) is not particularly limited, and when the insertion part 20 is inserted into the hollow part of the winding core 12, the height of the protrusion 22 (height from the outer peripheral surface of the insertion part 20) is such that when the insertion part 20 is inserted into the hollow part of the winding core 12, There is no particular restriction as long as the height is such that the portion 22 comes into contact with it. Among these, 0.1 to 5 mm is preferable, 0.5 to 2 mm is more preferable, and even more preferably 0.5 to 1.5 mm.
Note that the height of the protrusion may be constant or may vary depending on the position. For example, in order to improve the effects of the present invention, the height of the protrusion may become lower toward the end of the protrusion in a direction perpendicular to the direction in which the protrusion extends.

The width in the direction perpendicular to the direction in which the protrusion 22 extends is not particularly limited, but is preferably 1 to 25 mm, more preferably 5 to 10 mm.

Note that the flange member is not limited to the forms shown in FIGS. 2 and 3; for example, as shown in FIG. 4, a hole 40 may be provided in the substrate 180 included in the flange member 140. By passing a finger through the hole 40, the assembly can be easily carried without dropping. In FIG. 4, eight holes 40 are provided, but the number is not particularly limited and may be one or more.

<Roll of first sheet>
The first sheet roll 16 is a roll of the first sheet 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.
FIG. 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 and a first layer 28 disposed on the support 26. The first sheet 24 shown in FIGS. 5 and 6, a pair of spacers 30 are arranged on the first sheet 24. In FIGS. As shown in FIGS. 5 and 6, the pair of spacers 30 are spaced apart in the width direction of the first sheet 24. In such an embodiment, when the first sheet 24 on which the pair of spacers 30 are placed is wound around the winding core, the presence of the spacers 30 causes the first layer 28 to It is possible to suppress contact between the support body 26 located on the side opposite to the winding core side, and it is possible to suppress destruction of the microcapsules in the first layer 28. Therefore, it is preferable that the assembly further includes a pair of spacers arranged between the first sheets of the roll of first sheets and spaced apart from each other in the width direction of the first sheets.
The specific configuration of the first sheet will be detailed later.

The material of the spacer 30 is not particularly limited, but rubber foam or elastic foam is preferred. Examples of the rubber foam include rubber foams selected from the group consisting of natural rubber, isoprene rubber, styrene rubber, nitrile rubber, butadiene rubber, chloroprene rubber, and urethane rubber. Examples of the elastic foam include elastic foams selected from the group consisting of polyethylene, polypropylene, polystyrene, polyvinyl chloride, and polyvinyl acetate.

Although the thickness of the spacer 30 is not particularly limited, it is preferably thicker than the first layer 28.
The thickness of the spacer 30 is often 1 to 10 mm, preferably 1 to 5 mm, and more preferably 2.5 to 5 mm, since the effects of the present invention are more excellent.

Although the static friction coefficient of the spacer 30 is not particularly limited, it is preferably 0.1 to 1.0 since the effects of the present invention are more excellent.
The coefficient of dynamic friction of the spacer 30 is not particularly limited, but it is preferably 0.1 to 1.0 since the effects of the present invention are more excellent.

The method of arranging the spacer 30 on the first sheet 24 is not particularly limited, and examples thereof include a method using double-sided tape and a method using an adhesive or a pressure-sensitive adhesive.

In FIGS. 5 and 6, the spacer 30 is provided over the entire length of the first sheet. Note that the present invention is not limited to this form, and the spacer may be provided in a portion of the first sheet in the longitudinal direction.

Note that although the spacer 30 is 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 may not include the spacer.

The stiffness in the width direction of the first sheet is not particularly limited, and is often 160 mN or more, and is preferably 170 mN or more, and more preferably 180 mN or more, since the effects of the present invention are more excellent. The upper limit is not particularly limited, but is often 500 mN or less, preferably 300 mN or less.
The stiffness in the longitudinal direction of the first sheet is not particularly limited, and is often 500 mN or less, and is preferably 200 mN or less, and preferably 160 mN or less, since the effects of the present invention are more excellent. The lower limit is not particularly limited, but is often 50 mN or more, preferably 100 mN or more.
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) was cut out from the first sheet, and using a LOOP STIFFNESS TESTER (manufactured by Toyo Seiki Seisakusho), the longitudinal and width directions of the cut out test piece were cut out. Measure stiffness. The 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. Two samples were measured, and the average value was taken as the above stiffness. More specifically, the above measurements are performed on two test pieces, and 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 stiffness obtained from the two test pieces is The average value of the stiffness in the width direction is defined as the stiffness in the width direction of the first sheet. When measuring the stiffness in the longitudinal direction of the first sheet, use a test piece cut out so that the longitudinal direction of the test piece is along the longitudinal direction of the first sheet, and measure the stiffness in the width direction of the first sheet. When making measurements, a test piece is used that is cut out so that the longitudinal direction of the test piece runs along the width direction of the first sheet.

Further, in the assembly 10 shown in FIGS. 1 to 3, the insertion portion 20 of the flange member 14 is inserted into the hollow part of the winding core 12 to fix both, but the method of fixing is not limited to this mode. .
For example, there is a protrusion on the outer circumferential surface of the end of the winding core, a recess into which the end of the winding core is inserted into the flange member, and a protrusion on the end of the winding core. The winding core and the flange member may be fixed by contacting the flange member.
Furthermore, a fixing method other than the method using the protrusion may be used. For example, the winding core and the flange member may be bonded and fixed with an adhesive. Further, the winding core and the flange member may be screwed together.

In the assembly of the present invention, the fixing strength between the winding core and the flange member is 20N or more, preferably 25N or more, and more preferably 28N or more, since the effects of the present invention are more excellent. Although the upper limit is not particularly limited, it is often 1000N or less, more often 500N or less, and even more often 200N or less.
The above-mentioned fixing strength is the strength (N) required for separating the winding core and the flange member, and is calculated by the following method.
When one flange member of the assembly is fixed and the other flange member is pulled away from the winding core along the direction in which the winding core direction extends, one flange member or the other flange member will move away from the winding core. The strength (N) when separated from the base is defined as the above-mentioned fixed strength. A force gauge (manufactured by IMADA, model number: ZTA-500N) is used to measure the fixing strength.
The method of adjusting the fixing strength is not particularly limited, and examples include a method of increasing the number of protrusions described above, and a method of adjusting the difference between the diameter of the circumscribed circle and the inner diameter of the winding core. Further, the fixing strength of the assembly can also be controlled by adjusting the material of the winding core. For example, when a hard winding core is used, the winding core is difficult to deform when the protrusion comes into contact with the inner wall of the winding core, so the fixing strength tends to be high. On the other hand, when a soft winding core is used, when the protrusion comes into contact with the inner wall of the winding core, the winding core deforms and relieves the pressure exerted by the protrusion, which tends to reduce the fixing strength.

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 that closes the opening.

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

The color of the package is not particularly limited, but examples include transparent color, brown, and black. Among these, from the viewpoint of light resistance, brown or black is preferred, and black is more preferred.

The assembly of the present invention may be combined with a second sheet having a second layer containing a color developer to form a set of sheets for pressure measurement.
The second sheet will be explained in detail later. The second sheet may be treated as an assembly. In other words, the pressure measurement sheet set of the present invention includes a winding core, a pair of flange members fixed to both ends of the winding core, and a first layer that is wound around the winding core and includes microcapsules containing a coloring agent. a first sheet having a core, a first assembly having a core, a pair of flange members fixed to both ends of the core, and a second layer containing a color developer wound around the core. and a second assembly comprising a second sheet and a second assembly.

When using the pressure measurement sheet set, the first sheet and the second sheet are stacked and used 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 break in the pressurized area, and the color forming agent encapsulated in the microcapsules comes out from the microcapsules and combines with the color developer in the second layer. A color reaction progresses between the two. As a result, color development progresses in the pressurized area.

The configurations of the first sheet and the second sheet will be described in detail below.

<First sheet>
The first sheet has a first layer containing microcapsules containing a color former. Among these, it is preferable that the first sheet has a first support and a first layer disposed on the first support.
Each member will be explained in detail below.

(First support)
The first support is a member for supporting the first layer. Note that if the first layer itself can be handled, the first sheet does not need to have the first support.

The first support has an elongated shape.
The elongated first support means a support whose length in the longitudinal direction is longer than the length in the width direction.
The width of the first support is not particularly limited, but is often 50 to 1500 mm, preferably 50 to 500 mm.

Examples of the first support include a resin film and synthetic paper.
Examples of the resin film include polyester films such as polyethylene terephthalate films, cellulose derivative films such as cellulose triacetate, polyolefin films such as polypropylene and polyethylene, and polystyrene films.
Examples of synthetic paper include those made by biaxially stretching polypropylene or polyethylene terephthalate to form a large number of microvoids (such as Yupo), those made using synthetic fibers such as polyethylene, polypropylene, polyethylene terephthalate, and polyamide, and These may be laminated on a part of paper, on one side or on both sides, and the like.
Among these, a resin film or synthetic paper is preferred, and a resin film is more preferred since the effects of the present invention are more excellent. It is preferable that the support is transparent, since the coloring properties can be visually recognized even when viewed from the support side.

The thickness of the first support is preferably 10 to 200 μm from the viewpoint of achieving better effects of the present invention.

(1st layer)
The first layer includes microcapsules encapsulating a color former.
Hereinafter, first, the materials constituting the microcapsules will be explained in detail.

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

Microcapsules have a capsule wall that encloses a core material.
Examples of the capsule wall material (wall material) of the microcapsules include known resins that have been conventionally used as wall materials for microcapsules containing a coloring agent in pressure-sensitive copying paper or heat-sensitive recording paper applications. Specific examples of the resin include polyurethane, polyurea, polyurethaneurea, melamine-formaldehyde resin, and gelatin.
Among these, in order to obtain better effects of the present invention, it is preferable that the capsule wall of the microcapsule contains at least one resin selected from the group consisting of polyurethaneurea, polyurethane, and polyurea.

Preferably, the capsule wall of the microcapsule is substantially composed of resin. "Substantially composed of resin" means that the resin content is 90% by mass or more, preferably 100% by mass, based on the total mass of the capsule wall. That is, it is preferable that the capsule wall of the microcapsule is made of resin.
Note that polyurethane is a polymer having multiple urethane bonds, and is preferably a reaction product formed from raw materials containing polyol and polyisocyanate.
Further, polyurea is a polymer having a plurality of urea bonds, and is preferably a reaction product formed from raw materials containing polyamine and polyisocyanate. Note that polyurea can also be synthesized using polyisocyanate without using polyamine, taking advantage of the fact that a part of polyisocyanate reacts with water to become polyamine.
Moreover, 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. In addition, when making a polyol and a polyisocyanate react, a part of polyisocyanate reacts with water and becomes a polyamine, and a polyurethane urea may be obtained as a result.
Further, the melamine-formaldehyde resin is preferably a reaction product formed from polycondensation of melamine and formaldehyde.

In addition, the said polyisocyanate is a compound which has two or more isocyanate groups, and aromatic polyisocyanate and aliphatic polyisocyanate are mentioned. The polyisocyanate may be, for example, an 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, such as a low-molecular polyol (e.g., aliphatic polyol, aromatic polyol). polyols), polyvinyl alcohols, polyether polyols, polyester polyols, polylactone polyols, castor oil polyols, polyolefin polyols, and hydroxyl group-containing amine compounds (for example, amino alcohols.Amino alcohols Examples 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.
In addition, the above-mentioned polyamine is a compound having two or more amino groups (primary amino group or secondary amino group), such as diethylenetriamine, triethylenetetramine, 1,3-propylene diamine, and hexanetriamine. Aliphatic polyvalent amines such as methylene diamine; epoxy compound adducts of aliphatic polyvalent amines; alicyclic polyvalent amines such as piperazine; 3,9-bis-aminopropyl-2,4,8,10-tetraoxa Examples include heterocyclic diamines such as spiro-(5,5) undecane.

The glass transition temperature of the capsule wall of the microcapsule is not particularly limited, but 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.
Prepare 50 sheets of the first layer (microcapsule layer) measuring 1 cm in length x 1 cm in width, and immerse them all in 10 ml of water and leave them for 24 hours to obtain an aqueous dispersion of microcapsules. In addition, when the first sheet includes the first support body, 50 first sheets measuring 1 cm long x 1 cm wide may be prepared and immersed.
The resulting aqueous dispersion of microcapsules is centrifuged at 15,000 rpm for 30 minutes to separate the microcapsules. Ethyl acetate is added to the separated microcapsules, and the mixture is further stirred at 25°C for 24 hours. Thereafter, the obtained solution is filtered, and the obtained residue is vacuum-dried at 60°C for 48 hours to obtain microcapsules (hereinafter also simply referred to as "measurement material") that do not contain anything inside. It will be done. In other words, a capsule wall material of a microcapsule whose glass transition temperature is to be measured is obtained.
Next, the thermal decomposition temperature of the obtained measurement material is measured using a thermogravimetric differential thermal analyzer TG-DTA (device name: DTG-60, Shimadzu Corporation). In addition, thermal decomposition temperature refers to the temperature of a material to be measured in atmospheric thermogravimetric analysis (TGA) when the temperature is raised from room temperature at a constant heating rate (10°C/min), and the mass of the material to be measured 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 determined 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. Measured in the range from ℃ to (thermal decomposition temperature (℃) - 5℃). As the glass transition temperature of the capsule wall of the microcapsule, 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 the microcapsules can be controlled by adjusting the manufacturing conditions of the microcapsules.
Here, the volume-based median diameter of a microcapsule is defined as the volume of particles on the large-diameter side and the small-diameter side when the entire microcapsule is divided into two using the particle size at which the cumulative volume is 50% as a threshold value. The diameter that makes the total equal. That is, the median diameter corresponds to what is 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 within a range of 500 μm x 500 μm. It is.

The number average wall thickness of the microcapsule (the number average wall thickness of the capsule wall of the microcapsule) is not particularly limited, but is preferably 0.01 μm or more and 2 μm or less, more preferably more than 0.02 μm and less than 2 μm, and 0.05 μm or more and 1. More preferably, the thickness is 5 μm or less.
Note that the wall thickness of a microcapsule refers to the thickness (μm) of the capsule wall forming the capsule particles of the microcapsule, and the number average wall thickness refers to the thickness (μm) of the individual capsule wall of five microcapsules. It refers to the average value calculated using a scanning electron microscope (SEM). More specifically, a cross-sectional section of the first sheet containing the first layer containing microcapsules was prepared, and the cross-section was observed with an SEM at 200 times magnification, and the value of (average particle diameter of microcapsules) x 0. After selecting five arbitrary microcapsules having a long axis in the range of 9 to (value of average particle size of microcapsules) x 1.1, observe the cross section of each selected microcapsule at 15,000 times magnification. Determine the thickness of the capsule wall and calculate the average value. In addition, the long diameter means the longest diameter when observing the microcapsule.

The ratio (δ/Dm) of the number average wall thickness δ of the microcapsules to the average particle diameter Dm of the microcapsules is not particularly limited, and is often 0.001 or more. Among these, it is preferable that the relationship of formula (1) is satisfied, since the effects of the present invention are 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. When the relationship of formula (1) is satisfied, the color density gradation can be set in a range that is easy to recognize depending on the pressure.

[Coloring agent]
A coloring agent is encapsulated within the microcapsule.
A color former is a compound that develops a color from a colorless state when it comes into contact with a color developer described below. As the coloring agent, an electron-donating dye precursor (precursor of a dye that develops color) is preferable. That is, as the coloring agent, an electron-donating colorless dye is preferable.
As the color former, those known for use in pressure-sensitive copying paper or heat-sensitive recording paper can be used. Examples of coloring agents include triphenylmethane phthalide compounds, fluoran compounds, phenothiazine compounds, indolylphthalide compounds, azaindolylphthalide compounds, leucoauramine compounds, rhodamine lactam compounds, and triphenylmethane phthalide compounds. Examples include phenylmethane compounds, diphenylmethane compounds, triazene compounds, spiropyran compounds, and fluorene compounds.
Examples of the above-mentioned compounds include the compounds described in JP-A-5-257272, the compounds described in paragraphs 0030 to 0033 of International Publication No. 2009/8248, and 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. The upper limit is not particularly limited, but is preferably 1000 or less.

[Other ingredients]
The microcapsules may contain other components other than the above-mentioned coloring agent.
For example, it is preferable that the microcapsules contain 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, alkyl biphenyl compounds such as isopropylbiphenyl, triarylmethane compounds, and alkylbenzene compounds. , aromatic hydrocarbons such as benzylnaphthalene compounds, diarylalkylene compounds, and arylindan compounds; aliphatic hydrocarbons such as dibutyl phthalate and 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 high-boiling fractions of natural products 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. The range of 97/3 to 40/60 is more preferable.

In addition to the above-mentioned components, the microcapsules may contain one or more additives such as ultraviolet absorbers, light stabilizers, antioxidants, waxes, and odor suppressants, if necessary.

[Method for manufacturing microcapsules]
The method for producing microcapsules is not particularly limited, and examples thereof include known methods such as interfacial polymerization, internal polymerization, phase separation, external polymerization, and coacervation. Among these, interfacial polymerization is preferred.
The interfacial polymerization method will be described below, taking as an example a method for producing microcapsules whose capsule walls are polyurea or polyurethane urea.
The interfacial polymerization method uses a raw material containing a coloring agent, a solvent with a boiling point of 100° C. or higher, and a capsule wall material (for example, a polyisocyanate and at least one member selected from the group consisting of polyols and polyamines. When polyamines are produced in-system by reacting isocyanate and water, polyols and polyamines do not need to be used.) A process of preparing an emulsion by dispersing an oil phase containing an emulsifier into an aqueous phase containing an emulsifier. (emulsification process); and a process (encapsulation process) of polymerizing the capsule wall material at the interface between the oil phase and the aqueous phase to form a capsule wall and forming microcapsules that encapsulate the coloring agent. Preferably legal.
Note that the mass ratio between the total amount of polyol and polyamine and the amount of polyisocyanate in the above raw materials (total amount of polyol and polyamine/amount of polyisocyanate) is not particularly limited, but is 0.1/99.9 to 30/70 is preferred, and 1/99 to 25/75 is more preferred.

Further, the type of emulsifier used in the emulsification step is not particularly limited, and examples thereof include dispersants and surfactants.
Examples of the dispersant include polyvinyl alcohol.

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

Further, the mass per unit area (g/m ² ) of the first layer is not particularly limited, but it is preferably 0.5 to 30 g/m ² in terms of the effect of the present invention being more excellent.

(Method for forming the first layer)
The method of forming the first layer is not particularly limited.
For example, a method may be mentioned in which a first layer-forming composition containing microcapsules is applied onto a first support, and the resulting coating film is subjected to a heat treatment at a predetermined temperature or higher.
In addition to the above method, there is also a method in which microcapsules are separately prepared and a first layer forming composition containing the microcapsules is applied onto the first support.
Below, a mode of heating at a predetermined temperature or higher will be described in detail.

The composition for forming the first layer preferably contains at least microcapsules and a solvent. Note that the microcapsule dispersion obtained by the interfacial polymerization method described above may be used as the first layer forming composition.
The first layer forming composition may contain other components that may be included in the first layer described above.

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

After applying the first layer forming composition onto the first support, the resulting coating film is subjected to a heat treatment at a predetermined temperature or higher.
As for the temperature conditions for the heat treatment, the optimum temperature is selected depending on the material of the capsule wall of the microcapsules used, but 60°C or higher is preferable, and 70°C or higher is preferable since the effects of the present invention are more excellent. More preferred. Although the upper limit is not particularly limited, it is often 180°C or lower, and in terms of better color density, it is preferably 140°C or lower, and more preferably 120°C or lower.
The heating time is not particularly limited, but from the viewpoint of better effects of the present invention and productivity, the heating time is preferably 1.0 to 20 minutes, more preferably 3.0 to 10 minutes.

In addition, although the method of forming the first layer on the first support was described above, the method is not limited to the above embodiment, and for example, after forming the first layer on the temporary support, the temporary support is peeled off. A first sheet consisting of a first layer may be formed.
The temporary support is not particularly limited as long as it is a peelable support.

(Other parts)
The first sheet may have members other than the first support and first layer described above.
For example, the first sheet may have an easily adhesive layer between the first support and the first layer to increase the adhesion between the two.
The thickness of the easily adhesive layer is not particularly limited, and is preferably 0.005 to 2 μm, more preferably 0.01 to 1 μm.

The arithmetic mean roughness Ra of the first sheet is not particularly limited, and is often 0.1 μm or more, and is preferably 2.5 to 7.0 μm in terms of better color density. In addition, 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 on the side facing (the side in contact with) the second sheet when using the pressure measurement sheet set. do. When the first layer is located 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 first support side. This corresponds to Ra.
Note that 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 an arithmetic mean roughness defined in JIS B 0681-6:2014. Means average roughness Ra. As the measuring device, a scanning white interferometer using an optical interference method (specifically, NewView 5020 manufactured by Zygo; objective lens × 50 times; intermediate lens × 0.5 times) is used. The measurement mode when measuring the arithmetic mean roughness Ra of the first sheet using the scanning white interferometer is Stitch mode, and the measurement mode when measuring the arithmetic mean roughness Ra of the second sheet is Micro mode. It is.

<Second sheet>
The second sheet has a second layer containing a color developer. Among these, the second sheet preferably includes a second support and a second layer disposed on the second support.
Each member will be explained in detail below.

(Second support)
The second support is a member for supporting the second layer. Note that if the second layer itself can be handled, the second sheet does not need to have the second support.
The aspect of the second support is not particularly limited, and examples thereof include the aspect of the first support described above.

(Second layer)
The second layer is a layer containing a color developer.
A color developer is a compound that does not have a color-forming function by itself, but has the property of causing the color-forming agent to develop color when it comes into contact with the color-forming agent. As the color developer, an electron-accepting compound is preferable.
Examples of the color developer include inorganic compounds and organic compounds, and the inorganic compounds and organic compounds described in paragraphs 0055 to 0056 of International Publication No. 2009/008248 are preferred. Acid clay, activated clay, or a metal salt of an aromatic carboxylic acid is preferable in terms of better color density and image quality after color development.

The content of the color developer in the second layer is not particularly limited, but 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. .

The content of the color developer in the second layer is not particularly limited, but is preferably 0.1 to 30 g/m ² . When the color developer is an inorganic compound, the content of the color developer is preferably 3 to 20 g/m ² , more preferably 5 to 15 g/m ² . When the color developer is an organic compound, the content of the color 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 above-mentioned color developer.
Other components include, for example, a polymer binder, a pigment, an optical brightener, an antifoaming agent, a penetrant, an ultraviolet absorber, a surfactant, and a preservative.
Examples of the polymer binder include styrene-butadiene copolymer, polyvinyl acetate, polyacrylic ester, polyvinyl alcohol, polyacrylic acid, maleic anhydride-styrene copolymer, olefin resin, and modified acrylic ester copolymer. , starch, casein, gum arabic, gelatin, carboxymethylcellulose or a salt thereof, and methylcellulose, and other synthetic and natural polymers.
Examples of the pigment include heavy calcium carbonate, light calcium carbonate, talc, and titanium dioxide.

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

(Method of forming second layer)
The method of forming the second layer is not particularly limited.
For example, a method may be used in which a second layer-forming composition containing a color developer is applied onto the second support and, if necessary, the resulting coating film is subjected to a drying treatment.
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 color developer is an inorganic compound, a dispersion in which the color developer is dispersed can be prepared by mechanically dispersing the inorganic compound in water. When the color developer is an organic compound, it can be prepared by mechanically dispersing the organic compound in water or dissolving it in an organic solvent.
The second layer forming composition may contain other components that may be included in the second layer described above.

The method for applying the second layer forming composition is not particularly limited, and examples include a method using the coating machine used when applying the first layer forming composition described above.

After coating the second layer-forming composition on the second support, the coating film may be subjected to a drying treatment, if necessary. Examples of the drying treatment include heat treatment.

In addition, although the method of forming the second layer on the second support was described above, the method is not limited to the above embodiment, and for example, after forming the second layer on the temporary support, the temporary support is peeled off. Then, a second sheet consisting of a second layer may be formed.
The temporary support is not particularly limited as long as it is a peelable support.

(Other parts)
The second sheet may include members other than the second support and second layer described above.
For example, the second sheet may have an easily adhesive layer between the second support and the second layer to increase the adhesion between the two.
Examples of the easily bonding layer include the easily bonding layer that may be included in the first sheet described above.

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 obtaining a body and applying pressure to the laminate.

The arithmetic mean roughness Ra of the second sheet is preferably 1.2 μm or less in terms of better color density. In addition, 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 on the side facing (the side in contact with) the first sheet when using the pressure measurement sheet set. do. When the second layer is located on the outermost surface of the second sheet facing the first sheet, the arithmetic mean roughness Ra is the arithmetic mean roughness of the surface of the second layer opposite to the second support side. This corresponds to Ra.

The present invention will be explained in more detail below based on Examples. The materials, usage amounts, proportions, processing details, processing procedures, etc. shown in the following examples can be changed as appropriate 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>
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). Further, a butylene oxide adduct of ethylenediamine (0.4 parts by mass) dissolved in methyl ethyl ketone (1 part by mass) was added to the stirring solution A to obtain a solution B. Furthermore, a trimethylolpropane adduct (2 parts by mass) of tolylene diisocyanate dissolved in methyl ethyl ketone (1 part by mass) was added to the stirring 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) and emulsified and dispersed. Water (300 parts by mass) was added to the emulsion after emulsification and dispersion, heated to 70°C while stirring, and cooled after stirring for 1 hour to prepare a microcapsule liquid containing microcapsules encapsulating a coloring agent. . 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 in a sand mill, SBR latex (corresponding to 15 parts by mass of solids), carboxymethyl cellulose 1 A mass % aqueous solution (15 parts by mass) and a 25 mass % sodium dodecylbenzenesulfonate aqueous solution (1 mass part) were added and mixed, and water was further added to make the solid content concentration 41.5 mass %. A layer-forming composition was prepared.

A coating solution containing styrene-butadiene copolymer latex was applied to one side of a long polyethylene terephthalate (PET) film having a width of 450 mm and a thickness of 75 μm, and then dried. Next, a coating solution containing gelatin and tin oxide was applied and dried to produce a PET film 1 having an easily adhesive layer with a thickness of 0.55 μm.

Next, on the easy-adhesive layer of the PET film 1, protective ear layers are formed at both ends of the PET film 1 in the width direction, and the above-mentioned layer is formed so that the first layer is formed between the protective ear layers. After applying the coloring agent-containing microcapsule liquid (A) and the composition for forming a protective ear layer, it was dried to obtain a sheet. In the obtained 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 center part of the sheet was cut into a width of 360 mm using a processing machine so as to remove the protective ear layers located at both ends of the obtained sheet in the width direction, and the sheet was placed on the PCT film 1 and the PET film 1. An elongated first sheet having a first layer formed by the following steps was obtained. The following double-sided tape was pasted on both edges in the width direction on the obtained first sheet, and the following cushion (spacer) was pasted, so that the spacer was arranged over the entire length in the longitudinal direction as shown in Figures 5 and 6. A first sheet was prepared.
Next, a hollow cylindrical winding core, which will be described later, and a flange member, which will be described later, were prepared. Note that the flange member had a substrate and a cylindrical insertion portion placed on the substrate, and a protrusion was placed on the surface of the insertion portion (see FIGS. 2 and 3). The insertion part of the flange member was inserted into the hollow part of the winding core, and the flange member was fixed to both ends of the winding core to produce a winding core with a flange member.
Next, the first sheet on which the spacer is arranged is wound around the winding core of the winding core with a flange member, and an assembly 1 as shown in FIG. was created.

-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 (Sekisui Chemical Co., Ltd., double tack tape #595), width: 10 mm
- Winding core -
Made of paper (resin impregnated), length: 390mm, inner diameter of hollow part: 76mm
-Flange member (see Figure 2)-
Material: polypropylene (PP), board shape: octagon, board size: 210 mm, diameter of circumscribed circle (circumscribed circle circumscribing the area consisting of the insertion part and protrusion when the flange member is observed from the normal direction of the board) Diameter): 77.5mm, Number of protrusions: 8 evenly spaced, Protrusion height: 1.3mm

<Examples 2 to 12, Comparative Example 1>
Assemblies 2 to 12 were produced according to the same procedure as in Example 1, except that various requirements shown in Table 1 described below were changed. Furthermore, regarding Comparative Example 1, an assembly C1 was also produced using a flange member without a protrusion.
Note that the inner diameter deformation rate, wall thickness deformation rate, and surface roughness Ra of the winding core were adjusted by changing the type of winding core used. Furthermore, the stiffness of the first sheet was adjusted by changing the type of PET film used.

<Preparation of second sheet>
Activated clay (BYK-chemie, FURACOLOR SR) (100 parts by mass), Na hexametaphosphate (Nihon 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 obtained dispersion, olefin resin (Arakawa Chemical Co., Ltd., Polymalon 482) (30 parts by mass), modified acrylic ester copolymer (Nippon Zeon, Nippor LX814) ( 35 parts by mass), 1% aqueous solution (80 parts by mass) of sodium carboxymethylcellulose (Daiichi Kogyo Seiyaku, Celogen EP), 15% aqueous solution (18 parts by mass) of Na alkylbenzenesulfonate (Daiichi Kogyo Seiyaku, Neogen T), 1% aqueous solution (20 parts by mass) of polyoxyethylene polyoxypropylene lauryl ether (Daiichi Kogyo Seiyaku, Neugen LP-70), sodium bis(3,3,4,4,5,5,6,6 , 6-nonafluorohexyl)-2-sulfinatooxysuccinate (Fujifilm, W-AHE) was mixed to form a second layer forming composition containing a clay substance. Obtained.
The above composition for forming a second layer was applied onto a PET sheet having a thickness of 75 μm so that the solid content coating amount was 7 g/m ² . Next, the obtained coating film was dried to form a second layer, and a second sheet was obtained.

In addition, in Example 11, compared to Examples 1 to 10, Example 12, and Comparative Example 1, a core made of a harder material was used.

<Measurement>
(Fixing strength)
Pass a rod through the winding core, fix one of the flange members with the heights of the two flange members horizontal, and attach a push-pull measuring device (model number: ZTA-500N, manufactured by IMADA) to the other flange member. was fixed. When the device was operated and the flange member to which the force gauge was fixed was pulled away from the winding core along the direction in which the winding core extended, one of the two flange members came off the winding core. The value was measured when The measurement was performed twice, and the average value was taken as the fixation strength [unit: N].

(Inner diameter change rate and wall thickness change rate)
The inner diameter change rate and wall thickness change rate were measured by Test 1 and Test 2 described above.

(Surface roughness)
Using a stylus type surface roughness meter (Handysurf E-35A, manufactured by Tokyo Seimitsu Co., Ltd.), the surface roughness (Ra) of the surface of the winding core was measured in accordance with ISO97. The measurement conditions were an evaluation length of 4 mm and a cutoff value of 0.8 mm. The above measurement was carried out three times, and the obtained measured values were arithmetic averaged to obtain the surface roughness.

(stiffness)
A test piece with a length 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, and the stiffness of the first sheet in the longitudinal and width directions was measured using a LOOP STIFFNESS TESTER (manufactured by Toyo Seiki Seisakusho). 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. Measurements were made for two samples, and the average value was taken as the stiffness. More specifically, the above measurements are performed on two test pieces, and 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 stiffness obtained from the two test pieces is The average value of the stiffness in the width direction was taken as the stiffness in the width direction of the first sheet. When measuring the stiffness in the longitudinal direction of the first sheet, use a test piece cut out so that the longitudinal direction of the test piece is along the longitudinal direction of the first sheet, and measure the stiffness in the width direction of the first sheet. When making measurements, a test piece was used that was cut out so that the longitudinal direction of the test piece was along the width direction of the first sheet.

<Evaluation>
(Drop test)
Each assembly was stripped on 1 corner, 3 edges, and 6 sides based on the distribution condition level I of JIS Z0202, and evaluated according to the following criteria. The results are shown in Table 1.
A: No trace of microcapsule destruction was observed.
B: Slight traces of microcapsule destruction were observed (practical usable level).
C: Many traces of broken microcapsules were observed.

(color development)
The first sheet included in each assembly and the second sheet cut into a size of 5 cm long x 5 cm wide are cut so that the surface of the first layer of the first sheet and the surface of the second layer of the second sheet face each other. The sheets were pressed together at a pressure of 0.5 MPa using a pressure press machine (DSF-C1-A, manufactured by Aida Engineering Co., Ltd.) to develop color. Thereafter, both stacked sheets were peeled off, and the density (DA) of the colored portion formed on the second sheet was measured using a densitometer RD-19 (manufactured by Gretag Macbeth).
Separately, the initial density (DB) of the unused second sheet was measured in the same manner. Then, the initial density DB was subtracted from the density DA to obtain the developed color density ΔD, which was evaluated using the following evaluation criteria. The results are shown in Table 1.
A (0.7≦ΔD): Color development was clearly observed.
B (0.2≦ΔD<0.7): Slight color development was observed.
C (ΔD<0.2): Almost no color development was observed.

In Table 1, the "difference" column corresponds to the difference between the diameter of the circumscribed circle and the inner diameter of the winding core (diameter of the circumscribed circle - inner diameter of the winding core).

As shown in Table 1, the desired effects were obtained using the assembly of the present invention.
In particular, by comparing Example 3 with other Examples, it was confirmed that more excellent effects can be obtained when the number of protrusions is 4 or more.
Further, from a comparison between Example 6 and other Examples, it was confirmed that more excellent effects can be obtained when the thickness of the spacer is 2.5 μm or more.
Further, from a comparison between Example 9 and other Examples, it was confirmed that more excellent effects can be obtained when the first sheet has a stiffness in the width direction (lateral direction) of 170 mN or more.

<Example 13>
Synthetic isoparaffin (Idemitsu Kosan Co., Ltd., IP Solvent 1620) (15 parts by mass), N,N,N',N'-tetrakis(2-hydroxypropyl)ethylenediamine (Co., Ltd.) dissolved in ethyl acetate (3 parts by mass) ) Adeka, Adeka Polyether EDP-300) (0.4 parts by mass) was added to stirring 1-phenyl-1-xylylethane (Nippon Oil Co., Ltd., Hysol SAS296) (78 parts by mass) to form a solution. I got a D.
Furthermore, a trimethylolpropane adduct of tolylene diisocyanate (DIC Corporation, Burnock D-750) (3 parts by mass) dissolved in ethyl acetate (7 parts by mass) was added to the stirring solution D. I got an E.
Then, the above solution E was added to a solution in which polyvinyl alcohol (PVA-205, manufactured by Kuraray Co., Ltd.) (69 parts by mass) was dissolved in water (140 parts by mass), and emulsified and dispersed. Water (340 parts by mass) was added to the emulsion after emulsification and dispersion, and the mixture was heated to 70° C. while stirring, and after stirring for 1 hour, it was cooled. Further, water was added to adjust the concentration to obtain a color former-free microcapsule liquid (B) with a solid content concentration of 19.6%.

Color former-containing microcapsule liquid (A) obtained above (18 parts by mass), color former non-containing microcapsule liquid (B) (2 parts by mass), water (63 parts by mass), colloidal silica (Nissan Chemical Co., Ltd.) , Snowtex (registered trademark) 30) (1.8 parts by mass), 10% aqueous solution (1.8 parts by mass) of carboxymethylcellulose Na (Daiichi Kogyo Seiyaku Co., Ltd., Celogen 5A), carboxymethylcellulose Na (Daiichi Kogyo Seiyaku Co., Ltd., Celogen 5A), 1% aqueous solution (30 parts by mass) of Kogyo Seiyaku Co., Ltd., Celogen EP), 15% aqueous solution (0.3 parts by mass) of sodium alkylbenzenesulfonate (Daiichi Kogyo Seiyaku Co., Ltd., Neogen T), and Neugen A specific composition was obtained by mixing a 1% aqueous solution (0.8 parts by mass) of LP70 (Daiichi Kogyo Seiyaku Co., Ltd.) and stirring for 2 hours.

Assembly 13 was produced according to the same procedure as <Preparation of assembly B> above, except that the above specific composition was used instead of the color former-containing microcapsule liquid (A).

<Examples 14 to 16>
Assemblies 14 to 16 were produced according to the same procedure as in Example 13, except that various requirements shown in Table 1 described below were changed.

The measurements and evaluations described above were performed using the assemblies 13 to 16 obtained above. The results are summarized in Table 2.

As shown in Table 2, the desired effects were obtained using the assembly of the present invention.
Further, from the results in Table 2, it was confirmed that more excellent effects were obtained when the first sheet had a stiffness in the width direction of 180 mN or more.

10 Assembly 12 Winding core 14,140 Flange member 16 First sheet roll 18,180 Substrate 20 Insertion section 22 Projection section 24 First sheet 26 Support body 28 First layer 30 Spacer 40 Hole section

Claims (10)

A winding core,
a pair of flange members fixed to both ends of the winding core;
an assembly comprising: a roll of the first sheet formed by winding a long first sheet having a first layer containing microcapsules encapsulating a coloring agent around the core; ,
An assembly in which the fixing strength between the winding core and the flange member is 20N or more. The winding core has a hollow cylindrical shape,
The flange member has a substrate and an insertion portion that can be inserted into a hollow portion of the winding core disposed on the substrate,
The assembly according to claim 1, wherein a protrusion is disposed on an outer circumferential surface of the insertion portion. The assembly according to claim 2, wherein the number of protrusions is three or more. The inner diameter change rate of the winding core obtained by Test 1 below is 1.0% or less,
The assembly according to claim 2 or 3, wherein the wall thickness change rate of the winding core obtained by Test 2 below is 10.0% or less.
Test 1: After the winding core was allowed to stand for 24 hours in an environment of 23° C. and 65% RH, the inner diameter of the winding core was measured at four locations to obtain the inner diameter before heating, and then the winding core was After the core was allowed to stand for 24 hours in an environment of 105°C, the inner diameter of the wound core at the four locations was measured to obtain the inner diameter after heating, and the inner diameter of the core was measured at the four locations. Using the front inner diameter and the inner diameter after heating, respectively, calculate the rate of change obtained by the following formula (1) at the four locations, and then calculate the value obtained by further arithmetic averaging the obtained average values. Let it be the rate of change in inner diameter.
Formula (1): Rate of change = {|Inner diameter after heating - Inner diameter before heating |/Inner diameter before heating} x 100
Test 2: After the winding core was allowed to stand for 24 hours in an environment of 23 ° C. and 65% RH, the wall thickness of the winding core was measured at four locations to obtain the wall thickness before heating, and then, After the winding core was allowed to stand for 24 hours in an environment of 105°C, the wall thickness of the winding core at the four locations was measured to obtain the wall thickness after heating, and the thickness obtained at the four locations was measured. Using the obtained wall thickness before heating and wall thickness after heating, respectively, calculate the rate of change obtained by the following formula (2) at the four locations, and further calculate the obtained average value by the arithmetic mean. The value obtained is the wall thickness change rate.
Formula (2): Rate of change = {|Thickness after heating - Thickness before heating | / Thickness before heating} x 100 A diameter of a circumscribed circle circumscribing a region consisting of the insertion portion and the protrusion when the flange member is observed from the normal direction of the substrate is 0.7 to 2.0 mm larger than the inner diameter of the winding core. The assembly according to any one of items 2 to 4. The assembly according to any one of claims 1 to 5, wherein the outer peripheral surface of the winding core has a surface roughness Ra of 1.0 to 4.0 μm. 7. The method according to claim 1, further comprising a pair of spacers arranged between the first sheets of the roll of the first sheets and spaced apart from each other in the width direction of the first sheets. assembly. An assembly according to claim 7, wherein the spacer has a thickness of 1 to 5 mm. The assembly according to any one of claims 1 to 8, wherein the first sheet has a stiffness in the width direction of 170 mN or more. An assembly according to any one of claims 1 to 9 ,
A pressure measurement sheet set comprising: a second sheet having a second layer containing a color developer.