CN114829893A - Pressure measurement sheet set, pressure measurement sheet, method for manufacturing pressure measurement sheet set, and method for manufacturing pressure measurement sheet - Google Patents
Pressure measurement sheet set, pressure measurement sheet, method for manufacturing pressure measurement sheet set, and method for manufacturing pressure measurement sheet Download PDFInfo
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- CN114829893A CN114829893A CN202080085495.6A CN202080085495A CN114829893A CN 114829893 A CN114829893 A CN 114829893A CN 202080085495 A CN202080085495 A CN 202080085495A CN 114829893 A CN114829893 A CN 114829893A
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- Prior art keywords
- microcapsules
- sheet
- layer
- pressure measurement
- pressure
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
- B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
- B41M5/00—Duplicating or marking methods; Sheet materials for use therein
- B41M5/124—Duplicating or marking methods; Sheet materials for use therein using pressure to make a masked colour visible, e.g. to make a coloured support visible, to create an opaque or transparent pattern, or to form colour by uniting colour-forming components
- B41M5/165—Duplicating or marking methods; Sheet materials for use therein using pressure to make a masked colour visible, e.g. to make a coloured support visible, to create an opaque or transparent pattern, or to form colour by uniting colour-forming components characterised by the use of microcapsules; Special solvents for incorporating the ingredients
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L1/00—Measuring force or stress, in general
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L5/00—Apparatus for, or methods of, measuring force, work, mechanical power, or torque, specially adapted for specific purposes
Abstract
The invention provides a pressure measurement sheet set for inhibiting color development caused by friction, a pressure measurement sheet, a method for manufacturing the pressure measurement sheet set and a method for manufacturing the pressure measurement sheet. The pressure measurement sheet set of the present invention includes: a 1 st sheet having a 1 st layer containing microcapsules containing a color former therein; and a 2 nd sheet having a 2 nd layer containing a developer, wherein at least a part of the microcapsules have pits in a capsule wall, and a ratio of the microcapsules having pits to a total number of the microcapsules is 20% or more.
Description
Technical Field
The present invention relates to a pressure-measuring sheet set, a pressure-measuring sheet, a method for manufacturing the pressure-measuring sheet set, and a method for manufacturing the pressure-measuring sheet.
Background
In recent years, the necessity of measuring the pressure distribution has been increasing due to the higher functionality and higher definition of products.
For example, patent document 1 proposes a pressure measurement material (pressure measurement sheet) that utilizes a color-developing reaction between an electron-donating leuco dye precursor and an electron-accepting compound.
Prior art documents
Patent literature
Patent document 1: japanese laid-open patent publication No. 2009-019949
Disclosure of Invention
Technical problem to be solved by the invention
On the other hand, in the pressure-measuring sheet, when slight friction is generated when the pressure-measuring sheet is assembled at a portion where the pressure distribution is measured, the portion where the friction is generated is colored, and it may be difficult to measure an accurate surface pressure distribution.
In view of the above circumstances, an object of the present invention is to provide a pressure measurement sheet set and a pressure measurement sheet that suppress color development due to friction.
Another object of the present invention is to provide a method for manufacturing a pressure measurement sheet set and a method for manufacturing a pressure measurement sheet.
Means for solving the technical problem
As a result of intensive studies on the above problems, the present inventors have found that the above problems can be solved by the following configuration.
(1) A pressure measurement sheet set is provided with:
a 1 st sheet having a 1 st layer containing microcapsules containing a color former therein; and
a 2 nd sheet having a 2 nd layer containing a color developer,
at least a portion of the microcapsules have dimples in the capsule wall,
the ratio of the microcapsules having the pits to the total number of the microcapsules is 20% or more.
(2) The pressure-measuring sheet set according to (1), wherein,
the average value of the ratio of the distance H from the bottom of the pit of the microcapsule having a pit to the outer surface of the capsule wall facing the pit to the maximum length L of the microcapsule having a pit in the direction orthogonal to the depth direction of the pit is 0.90 or less.
(3) The set of pressure-measuring sheets according to (2), wherein,
the average value of the ratio is 0.50 to 0.90.
(4) The pressure-measuring sheet set according to any one of (1) to (3), wherein,
the microcapsule having a pit has 1 pit.
(5) The pressure-measuring sheet set according to any one of (1) to (4),
the capsule wall of the microcapsules comprises at least 1 resin selected from the group consisting of polyurethaneureas, polyurethanes, and polyureas,
the glass transition temperature of the capsule wall is 50-160 ℃.
(6) The pressure-measuring sheet set according to any one of (1) to (5), wherein,
the microcapsules have a number average wall thickness of more than 0.02 [ mu ] m and less than 2 [ mu ] m.
(7) The pressure-measuring sheet set according to any one of (1) to (6),
the microcapsules satisfy the relationship of the formula (1) described later.
(8) The pressure-measuring sheet set according to any one of (1) to (7), wherein,
the arithmetic average roughness Ra of the No. 1 sheet is 2.5 to 7.0 μm.
(9) The pressure-measuring sheet set according to any one of (1) to (8), wherein,
the arithmetic average roughness Ra of the No. 2 sheet was 1.2 μm or less.
(10) The pressure measurement sheet set according to any one of (1) to (9), wherein,
the 1 st sheet also has a support,
the pits of the microcapsules having the pits are located on the side opposite to the support side.
(11) The pressure-measuring sheet set according to (10), wherein,
the support body is a resin film,
(12) a pressure-measuring sheet comprising:
layer 1 comprising microcapsules containing a color former therein; and
a 2 nd layer disposed on the 1 st layer and containing a color developer,
at least a portion of the microcapsules have dimples in the capsule wall,
the ratio of the microcapsules having the pits to the total number of the microcapsules is 20% or more.
(13) The pressure-measuring sheet according to (12), wherein,
the average value of the ratio of the distance H from the bottom of the pit of the microcapsule having a pit to the outer surface of the capsule wall facing the pit to the maximum length L of the microcapsule having a pit in the direction orthogonal to the depth direction of the pit is 0.90 or less.
(14) The pressure-measuring sheet according to (13), wherein,
the average value of the ratio is 0.50 to 0.90.
(15) The pressure-measuring sheet according to any one of (12) to (14), wherein,
the microcapsule having a pit has 1 pit.
(16) The pressure-measuring sheet according to any one of (12) to (15), wherein,
the capsule wall of the microcapsules comprises at least 1 resin selected from the group consisting of polyurethaneureas, polyurethanes, and polyureas,
the glass transition temperature of the capsule wall is 50-160 ℃.
(17) The pressure-measuring sheet according to any one of (12) to (16),
the microcapsules have a number average wall thickness of more than 0.02 [ mu ] m and less than 2 [ mu ] m.
(18) The pressure-measuring sheet according to any one of (12) to (17), wherein,
the microcapsules satisfy the relationship of the formula (1) described later.
(19) The pressure-measuring sheet according to any one of (12) to (18), further comprising a support,
the pits of the microcapsules having the pits are located on the side opposite to the support side.
(20) The pressure-measuring sheet according to (19), wherein,
the support is a resin film.
(21) A method for manufacturing a pressure measurement sheet set according to any one of (1) to (11), comprising:
a composition for forming layer 1 containing microcapsules containing a color former is applied, and the obtained coating film is subjected to a heat treatment at 60 ℃ or higher to form layer 1.
(22) A method for manufacturing a sheet for pressure measurement according to any one of (12) to (20), comprising:
a composition for forming layer 1 containing microcapsules containing a color former is applied, and the obtained coating film is subjected to a heat treatment at 60 ℃ or higher to form layer 1.
Effects of the invention
According to the present invention, a pressure measurement sheet set and a pressure measurement sheet can be provided that suppress color development due to friction.
Further, according to the present invention, a method of manufacturing a pressure measurement sheet set and a method of manufacturing a pressure measurement sheet can be provided.
Drawings
Fig. 1 is a sectional view of an embodiment of a pressure measurement sheet set.
Fig. 2 is a diagram for explaining a usage form of the pressure measurement sheet set.
Fig. 3 is an external view for explaining microcapsules having pits.
Fig. 4 is a cross-sectional view of a microcapsule having a pit.
Fig. 5 is an enlarged view showing an embodiment of the layer 1 containing microcapsules having pits.
Fig. 6 is a cross-sectional view of an embodiment of a pressure-measuring sheet.
Fig. 7 is a magnified photograph based on a scanning electron microscope of a microcapsule having pits.
Detailed Description
The present invention will be described in detail below.
In the present specification, the numerical range expressed by the term "to" means a range including numerical values before and after the term "to" as a lower limit value and an upper limit value.
In the numerical ranges recited in the present invention, an upper limit or a lower limit recited in a certain numerical range may be replaced with an upper limit or a lower limit recited in another numerical range recited in a stepwise manner. In the numerical ranges described in the present specification, the upper limit or the lower limit described in a certain numerical range may be replaced with the values shown in the examples.
The various components described later may be used singly in 1 kind or in combination of 2 or more kinds. For example, the polyisocyanate described later may be used alone in 1 kind or in a mixture of 2 or more kinds.
As a characteristic point of the pressure measurement sheet set and the pressure measurement sheet of the present invention, there is a point where a microcapsule having a pit (hereinafter, simply referred to as "specific microcapsule") is used. Although the details of the mechanism of the present invention are not clear, the specific microcapsules are hardly broken by friction, and as a result, if the layer 1 containing the specific microcapsules is used, color development due to friction can be suppressed.
[ 1 st embodiment ]
Fig. 1 is a sectional view of an embodiment of a pressure measurement sheet set.
The pressure measurement sheet set 10 includes a 1 st sheet 16 and a 2 nd sheet 22, the 1 st sheet 16 having a 1 st support body 12 and a 1 st layer 14 disposed on the 1 st support body 12 and containing microcapsules, and the 2 nd sheet 22 having a 2 nd support body 18 and a 2 nd layer 20 disposed on the 2 nd support body 18 and containing a color developer. At least a part of the microcapsules is a specific microcapsule.
As shown in fig. 2, when the pressure measurement sheet set 10 is used, the 1 st sheet 16 and the 2 nd sheet 22 are stacked and used such that the 1 st layer 14 of the 1 st sheet 16 and the 2 nd layer 20 of the 2 nd sheet 22 face each other. By applying pressure from at least one of the 1 st support body 12 side of the 1 st sheet 16 and the 2 nd support body 18 side of the 2 nd sheet 22 in the obtained laminate, the microcapsules are broken in the pressurized region, and the color former contained in the microcapsules comes out from the microcapsules to undergo a color developing reaction with the color developer in the 2 nd layer 20. As a result, color development proceeds in the pressurized region.
As will be described later, the 1 st sheet 16 may have the 1 st layer 14, or may not have the 1 st support 12. The 2 nd sheet 22 may have the 2 nd layer 20, or may not have the 2 nd support 18.
In fig. 1, the 1 st support 12 and the 1 st layer 14 are directly laminated, but the present invention is not limited to this embodiment, and another layer (for example, an easy adhesion layer) may be disposed between the 1 st support 12 and the 1 st layer 14, as described later. In fig. 1, the 2 nd support 18 and the 2 nd layer 20 are directly laminated, but the present invention is not limited to this embodiment, and another layer (for example, an easy adhesion layer) may be disposed between the 2 nd support 18 and the 2 nd layer 20 as described later.
The structure of the 1 st sheet 16 and the 2 nd sheet 22 constituting the pressure measurement sheet set 10 will be described in detail below.
< 1 st sheet >
The 1 st sheet 16 shown in fig. 1 has a 1 st support body 12 and a 1 st layer 14 containing microcapsules containing a color former.
Hereinafter, each member will be described in detail.
< No. 1 support >
The 1 st support is a member for supporting the 1 st layer. In addition, in the case of being able to be handled by the 1 st layer itself, the 1 st sheet may not have the 1 st support.
The 1 st support may have any one of a sheet shape, a film shape, and a plate shape.
Examples of the 1 st support include a resin film and a synthetic paper.
Examples of the resin film include polyester films such as polyethylene terephthalate films, cellulose derivative films such as cellulose triacetate films, polyolefin films such as polypropylene and polyethylene films, and polystyrene films.
Examples of the synthetic paper include synthetic paper having a plurality of micropores formed by biaxial stretching of polypropylene, polyethylene terephthalate, or the like (Yupo or the like), synthetic paper made of synthetic fibers of polyethylene, polypropylene, polyethylene terephthalate, polyamide, or the like, and synthetic paper having these layers laminated on a part, one surface, or both surfaces of the paper.
Among these, from the viewpoint of further suppressing color development due to friction (hereinafter, simply referred to as "the effect of the present invention is more excellent"), and from the viewpoint of further increasing the color development density by pressurization, a resin film or a synthetic paper is preferable, and a resin film is more preferable. The support is preferably transparent from the viewpoint of visibility of the color-developing property even when viewed from the support side.
From the viewpoint of further improving the effect of the present invention, the thickness of the 1 st support is preferably 10 to 200. mu.m.
< layer 1 >)
Layer 1 contains microcapsules containing a color former. In addition, at least a portion of the microcapsules have dimples on the capsule wall. That is, at least a part of the total number of microcapsules containing a color former in the layer 1 is a specific microcapsule.
Hereinafter, the material constituting the microcapsule will be described in detail.
Microcapsules generally include a core and a capsule wall for enclosing a core material (enclosed component (also referred to as an enclosed component)) constituting the core.
In the present invention, the microcapsule contains a color former as a core material (an inclusion component). Since the microcapsules contain the color former therein, the color former can be stably present until the microcapsules are broken by pressurization.
The microcapsules have a capsule wall enclosing a core material.
As the material (wall material) of the capsule wall of the microcapsule, there can be cited known resins which have been conventionally used as the wall material of the microcapsule containing a color former for the use in pressure-sensitive copying paper or thermal recording paper. Specific examples of the resin include polyurethane, polyurea, polyurethaneurea, melamine-formaldehyde resin, and gelatin.
Among them, from the viewpoint of further improving the effect of the present invention, the capsule wall of the microcapsule preferably contains at least 1 resin selected from the group consisting of polyurethaneurea, polyurethane, and polyurea.
The capsule wall of the microcapsule is preferably substantially composed of a resin. The substantial resin composition means that the content of the resin is 90% by mass or more, preferably 100% by mass, based on the total mass of the capsule wall. That is, the capsule wall of the microcapsule is preferably made of a resin.
The polyurethane is a polymer having a plurality of urethane bonds, and is preferably a reaction product formed from raw materials including a polyol and a polyisocyanate.
The polyurea is a polymer having a plurality of urea bonds, and is preferably a reaction product formed from a raw material containing a polyamine and a polyisocyanate. Further, a polyamine is formed by reacting a part of polyisocyanate with water, and polyurea can be synthesized using polyisocyanate without using polyamine.
The polyurethaneurea is a polymer having a urethane bond and a urea bond, and is preferably a reaction product formed from raw materials including a polyol, a polyamine, and a polyisocyanate. When the polyol is reacted with the polyisocyanate, a part of the polyisocyanate reacts with water to form a polyamine, and as a result, a polyurethaneurea can be obtained.
Also, the melamine-formaldehyde resin is preferably a reaction product formed by polycondensation of melamine and formaldehyde.
The polyisocyanate is a compound having 2 or more isocyanate groups, and examples thereof include aromatic polyisocyanates and aliphatic polyisocyanates. The polyisocyanate may be, for example, an adduct (adduct) of a polyol such as trimethylolpropane and a 2-functional polyisocyanate.
The polyol is a compound having 2 or more hydroxyl groups, and examples thereof include low-molecular polyols (e.g., aliphatic polyols and aromatic polyols), "low-molecular polyols" are polyols having a molecular weight of 400 or less), polyvinyl alcohols, polyether polyols, polyester polyols, polylactone polyols, castor oil polyols, polyolefin polyols, and hydroxyl group-containing amine compounds (e.g., aminoalcohols).
The polyamine is a compound having 2 or more amino groups (primary amino groups or secondary amino groups), and examples thereof include aliphatic polyamines such as diethylenetriamine, triethylenetetramine, 1, 3-propanediamine, and hexamethylenediamine; epoxy compound adducts of aliphatic polyamines; alicyclic polyamines such as piperazine; heterocyclic diamines such as 3, 9-bis-aminopropyl-2, 4,8, 10-tetraoxaspiro- (5,5) undecane.
The glass transition temperature of the capsule wall of the microcapsule is not particularly limited, but is preferably 50 to 160 ℃, more preferably 80 to 150 ℃ from the viewpoint of easy formation of a specific microcapsule in the 1 st layer when the 1 st layer is formed.
The method for measuring the glass transition temperature of the capsule wall is as follows.
50 1 st layers (microcapsule layers) of 1cm in length by 1cm in width were prepared, and the whole was immersed in 10ml of water and allowed to stand for 24 hours to obtain an aqueous microcapsule dispersion. In addition, when the 1 st sheet includes the 1 st support, 50 1 st sheets of 1cm in length × 1cm in width may be prepared and impregnated.
The obtained aqueous dispersion of microcapsules was centrifuged at 15000rpm for 30 minutes to collect the microcapsules. Ethyl acetate was added to the separated microcapsules, and further stirred at 25 ℃ for 24 hours. Then, the obtained solution was filtered, and the obtained residue was vacuum-dried at 60 ℃ for 48 hours, whereby microcapsules (hereinafter, also simply referred to as "measurement material") having no inside encapsulated therein were obtained. That is, a microcapsule wall material of a microcapsule to be measured for the glass transition temperature can be obtained.
Next, the thermal decomposition temperature of the obtained measurement material was measured using a thermogravimetric differential thermal analysis apparatus TG-DTA (apparatus name: DTG-60, Shimadzu Corporation). The thermal decomposition temperature is a temperature at which the measurement material is heated from room temperature at a predetermined temperature increase rate (10 ℃/min) in thermogravimetric analysis (TGA) in an atmospheric environment and the mass of the measurement material before heating is reduced by 5 mass%, and is referred to as a thermal decomposition temperature (c).
Next, the glass transition temperature of the measurement material was measured using a differential scanning calorimeter (device name: DSC-60a Plus, Shimadzu Corporation) and a closed pan at a temperature rise rate of 5 ℃/min in the range of 25 ℃ to (thermal decomposition temperature (. degree. C.) -5 ℃ C.). The glass transition temperature of the capsule wall of the microcapsule is the value at the time of temperature rise in cycle 2.
The average particle diameter of the microcapsules is not particularly limited, but is preferably 1 to 80 μm, more preferably 5 to 70 μm, and still more preferably 10 to 50 μm.
The average particle diameter of the microcapsules can be controlled by adjusting the production conditions of the microcapsules, and the like.
As a method for measuring the average particle diameter of the microcapsules, an image taken from the surface of the layer 1 was analyzed by an optical microscope (OLYMPUS BX60, size of field: 320. mu. m.times.450. mu.m), and the major diameters (particle diameters) of 30 microcapsules were measured sequentially from the largest microcapsule, and the average value was obtained by arithmetically averaging these. This operation was performed at arbitrary 5 sites (5 fields) in the 1 st layer, and the average of the average values obtained at each site was obtained, and the obtained value was defined as the average particle diameter of the microcapsules. The major axis means the longest diameter when the microcapsules are observed.
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 further preferably 0.05 μm or more and 1.5 μm or less.
The thickness of the microcapsule is the thickness (μm) of the capsule wall of the capsule particles forming the microcapsule, and the number average thickness is an average value obtained by obtaining the thickness (μm) of each of the capsule walls of 20 microcapsules by a Scanning Electron Microscope (SEM). More specifically, a cross-sectional slice of the 1 st sheet having the 1 st layer containing microcapsules was prepared, the cross-section was observed at 15000 times by SEM, and arbitrary 20 microcapsules having a major diameter in the range of (the value of the average particle diameter of the microcapsules) × 0.9 to (the value of the average particle diameter of the microcapsules) × 1.1 were selected, and then the cross-section of each of the selected microcapsules was observed to determine the thickness of the capsule wall, and the average value was calculated. The major axis means the longest diameter when the microcapsules are observed.
The ratio (δ/Dm) of the number average wall thickness δ of the microcapsule to the average particle diameter Dm of the microcapsule is not particularly limited, and is usually 0.001 or more. Among them, from the viewpoint of further improving the effect of the present invention, it is preferable that the relationship of the formula (1) is satisfied.
Formula (1)0.100 & gt delta/Dm & gt 0.001
That is, the ratio (δ/Dm) is preferably greater than 0.001 and less than 0.100. When the relationship of the formula (1) is satisfied, a range in which the color development intensity level can be easily recognized can be set by the pressure.
(microcapsules with pits (special microcapsules))
At least a portion of the microcapsules have dimples in the capsule wall. That is, the layer 1 contains microcapsules having pits (specific microcapsules).
Certain microcapsules have pits in the capsule wall.
Fig. 3 is a diagram showing an appearance of an example of a specific microcapsule. Figure 4 is a cross-sectional view of the particular microcapsule shown in figure 3.
As shown in fig. 3, a specific microcapsule (microcapsule having a pit) 24 has a pit 26 in the capsule wall.
In this specification, a pit means a region recessed from its periphery. The dimples typically have sides and/or a bottom. In other words, the dimples are regions that are convex toward the inside of the microcapsules (more specifically, the center of the microcapsules). The center of the microcapsule refers to the center of the circumscribed sphere that circumscribes the microcapsule.
In fig. 3, the specific microcapsule 24 has 1 pit 26, but the specific microcapsule may have 2 or more pits.
In fig. 3, the opening of the recess 26 has a circular shape, but the shape is not limited to this, and examples thereof include a polygonal shape, an elliptical shape, and an amorphous shape.
The shape of the opening of the pit 26 can be confirmed by observing from the surface direction of the layer 1.
In fig. 4, a cross section cut through the pits 26 (bottoms of the pits 26) of the specific microcapsules 24 and along the depth direction of the pits 26 is shown.
As shown in fig. 4, the maximum length L is the maximum length among the lengths of the specific microcapsules 24 in the direction perpendicular to the depth direction of the pits 26 indicated by the white arrow.
As shown in fig. 4, the distance from the bottom of the recess 26 to the outer surface of the capsule wall 28 facing the recess 26 is defined as a distance H. The bottom of the pit 26 is a position located at the deepest position in the depth direction of the pit 26 (the direction indicated by the white arrow in fig. 4). The capsule wall 28 facing the concave pits 26 is the capsule wall 28 at a position facing the concave pits 26 in the depth direction.
From the viewpoint of more excellent effects of the present invention and the viewpoint of more excellent color development intensity, the average value of the ratio (H/L) of the distance H from the bottom of the pit 26 of the specific microcapsule 24 to the outer surface of the capsule wall 28 facing the pit 26 to the maximum length L of the specific microcapsule 24 in the direction orthogonal to the depth direction (pit direction) of the pit 26 as shown in fig. 4 is preferably 0.90 or less, and more preferably 0.50 to 0.90.
As the method for measuring the maximum length L, an image taken from the surface of the layer 1 was analyzed by an optical microscope (OLYMPUS BX60, size of field: 320. mu. m.times.450. mu.m), the maximum length L of the specific microcapsule observed in the field was measured, and the average value of these was defined as "the maximum length L of the specific microcapsule" obtained when the above ratio (H/L) was obtained.
Further, as the method for measuring the distance H, the height of each of the specific microcapsules and the depth of the pit observed in the field of view are measured by observing the microcapsules from the surface direction of an arbitrary position of the layer 1 with a laser microscope (KEYENCE VK-8510, size of field of view: 100. mu. m.times.150. mu.m), the value of the pit depth is subtracted from the value of the height obtained to obtain the distance H of each specific microcapsule, and the average value of these values is defined as "the distance H from the bottom of the pit of the specific microcapsule to the outer surface of the capsule wall facing the pit" when the above-mentioned ratio (H/L) is obtained.
The ratio of the specific microcapsules to the total number of microcapsules contained in the 1 st layer is 20% or more, and from the viewpoint of further improving the effect of the present invention, is preferably 40% or more, and more preferably 60% or more. The upper limit is not particularly limited, and may be 100%.
As a method for measuring the ratio of the specific microcapsules, first, the total number of microcapsules observed in the field of view is measured by observing the microcapsules from the surface direction of an arbitrary position of the layer 1 with a laser microscope (KEYENCE VK-8510, size of field of view: 100. mu. m.times.150. mu.m), and the number of specific microcapsules observed in the field of view is measured to determine the ratio of the specific microcapsules to the total number of microcapsules. This operation was performed at arbitrary 5 sites (5 fields) of the 1 st layer, and the average of the ratios obtained at each site was obtained, and the obtained value was defined as the "ratio of specific microcapsules to the total number of microcapsules included in the 1 st layer".
The size of the opening of the dimple is not particularly limited, and as shown in fig. 4, the ratio of the maximum width W of the opening of the dimple 26 to the maximum length L (maximum width W/maximum length L) is preferably 0.10 to 0.95, and more preferably 0.30 to 0.85, from the viewpoint of further improving the effect of the present invention.
As a method for measuring the maximum width W, an image taken from the surface of the layer 1 was analyzed by an optical microscope (OLYMPUS BX60, size of field: 320. mu. m.times.450. mu.m), the maximum width W of the opening of a specific microcapsule observed in the field was measured, and the average value of these was defined as "the maximum width W of the opening" when the ratio (maximum width W/maximum length L) was obtained.
The depth of pit 26 is not particularly limited, and from the viewpoint of further improving the effect of the present invention, the ratio (depth D/distance H) of depth D (depth of pit) from the opening of pit 26 to the bottom of pit 26 to distance H is preferably 0.10 or more, and more preferably 0.10 to 1.00.
As the method for measuring the depth D, the depth of a specific microcapsule observed in the field of view is measured by observing the microcapsule from the surface direction of an arbitrary position of the layer 1 with a laser microscope (KEYENCE VK-8510, size of field of view: 100. mu. m.times.150. mu.m), and the average value of these is defined as "depth D" when the above ratio (depth D/distance H) is obtained.
The specific microcapsule also has a capsule wall enclosing a core material containing a color former as described above.
In addition to the specific microcapsules having pits, various characteristics (for example, the material of the capsule wall, the number-average wall thickness of the capsule wall, the average particle diameter, and the glass transition temperature of the capsule wall) are as described above.
In the case where the 1 st sheet contains a support, from the viewpoint of further improving the effect of the present invention, as shown in fig. 5, it is preferable that the pits 26 of the specific microcapsules 24 are located on the opposite side to the 1 st support 12 side in the 1 st support 12 and the 1 st layer 14 disposed on the 1 st support 12. Fig. 5 is an enlarged view of the 1 st layer 14, and as shown in fig. 5, the 1 st layer 14 may include a plurality of specific microcapsules 24.
In addition, the microcapsules contained in the layer 1 may contain microcapsules having no pits in addition to the specific microcapsules.
(color former)
The color former is encapsulated in the microcapsule.
The color former is a compound that develops color from a colorless state by contacting with a color developer described later. The color former is preferably an electron-donating pigment precursor (a precursor of a color-forming pigment). That is, as the color former, an electron-donating leuco dye is preferable.
As the color former, a color former known for use in pressure-sensitive copying paper or thermal recording paper can be used. Examples of the color former include triphenylmethane phthalide compounds, fluoran precursor compounds, phenothiazine compounds, indolylphthalolide compounds, azaindolylphthalolide compounds, white gold amine compounds, rhodamine lactam compounds, triphenylmethane compounds, diphenylmethane compounds, triazene compounds, spiropyran compounds, and fluorene compounds.
Examples of the above-mentioned compounds include a compound described in Japanese patent laid-open No. 5-257272, a compound described in paragraphs 0030 to 0033 of International publication No. 2009/8248, 3 ', 6' -bis (diethylamino) -2- (4-nitrophenyl) spiro [ isoindole-1, 9 '-xanthen ] -3-one, a parent 6' - (diethylamino) -1 ', 3' -dimethylfluorane, and 3, 3-bis (2-methyl-1-octyl-3-indolyl) phthalide.
The color former may be used alone in 1 kind, or may be used in combination in 2 or more kinds.
The molecular weight of the color former is not particularly limited, but is preferably 300 or more. The upper limit is not particularly limited, but is preferably 1000 or less.
(other Components)
The microcapsule may contain other components than the above-described color former.
For example, the solvent in the microcapsule is preferable.
The solvent is not particularly limited, and examples thereof include aromatic hydrocarbons such as alkyl naphthalene compounds such as diisopropylnaphthalene, diarylalkane compounds such as 1-phenyl-1-ditolylethane, alkyl biphenyl compounds such as isopropylbiphenyl, triarylmethane compounds, alkylbenzene compounds, benzylnaphthalene compounds, diarylalkylene compounds, and arylindene alkane compounds; aliphatic hydrocarbons such as dibutyl phthalate and isoparaffin; natural animal and vegetable oils such as soybean oil, corn oil, cottonseed oil, rapeseed oil, olive oil, coconut oil, castor oil and fish oil, and natural high-boiling fractions such as mineral oil.
The solvent may be used alone in 1 kind, or may be used in combination of 2 or more kinds.
When the solvent is contained in the microcapsule, the mass ratio of the solvent to the color former (mass of solvent/mass of color former) is preferably in the range of 98/2 to 30/70, more preferably in the range of 97/3 to 40/60, from the viewpoint of color formation.
The microcapsule may contain 1 or more kinds of additives such as an ultraviolet absorber, a light stabilizer, an antioxidant, paraffin, and an odor inhibitor, as necessary, in addition to the above components.
(method for producing microcapsule)
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.
The interfacial polymerization method will be described below by taking as an example a method for producing microcapsules having a capsule wall made of polyurea or polyurethaneurea.
The interfacial polymerization method is preferably an interfacial polymerization method including a step (emulsification step) of preparing an emulsion by dispersing an oil phase containing a color former, a solvent having a boiling point of 100 ℃ or higher, and a capsule wall material (for example, a raw material containing at least 1 selected from polyisocyanate, polyol, and polyamine) in an aqueous phase containing an emulsifier without using polyol and polyamine when the polyisocyanate is reacted with water to produce polyamine in a reaction system, and a step (encapsulation step) of polymerizing the capsule wall material at the interface between the oil phase and the aqueous phase to form a microcapsule containing the color former and to form a microcapsule containing the color former.
The mass ratio of the total amount of the polyol and the polyamine to the amount of the polyisocyanate in the raw material (total amount of the polyol and the polyamine/amount of the polyisocyanate) is not particularly limited, but is preferably 0.1/99.9 to 30/70, and more preferably 1/99 to 25/75.
The type of the emulsifier used in the emulsification step is not particularly limited, and examples thereof include a dispersant and a surfactant.
Examples of the dispersant include polyvinyl alcohol.
Layer 1 may contain other components (e.g., binder, surfactant) in addition to the microcapsules described above.
And, the mass per unit area (g/m) of the 1 st layer 2 ) The amount of the surfactant is not particularly limited, but is preferably 0.5 to 30g/m from the viewpoint of further improving the effect of the present invention 2 。
< method for forming layer 1 >
The method for forming the layer 1 is not particularly limited.
For example, a method in which the 1 st layer forming composition containing microcapsules is applied to the 1 st support and the obtained coating film is subjected to a heat treatment at a predetermined temperature or higher is exemplified. By performing the heating treatment at a predetermined temperature or higher, the solvent in the microcapsules is volatilized, and pits are generated in at least a part of the microcapsules supplied to the 1 st support, thereby forming the 1 st layer containing the specific microcapsules.
In addition to the above, a method may be mentioned in which specific microcapsules are separately prepared and the composition for forming the layer 1 including the specific microcapsules is applied to the support 1.
Hereinafter, a heating method at a predetermined temperature or higher will be described in detail.
The composition for forming the layer 1 preferably contains at least microcapsules and a solvent. In addition, the microcapsule dispersion obtained by the interfacial polymerization method described above may also be used as the composition for forming the 1 st layer.
The composition for forming the layer 1 may contain other components that may be contained in the layer 1.
The method for coating the composition for forming layer 1 is not particularly limited, and examples of a coater used for coating include an air knife coater, a bar coater, a curtain coater, a gravure coater, a squeeze coater, a die coater, a slide bead coater, and a blade coater.
After the composition for forming the layer 1 was applied to the support 1, the obtained coating film was subjected to a heat treatment at a predetermined temperature or higher.
The temperature condition for the heat treatment is preferably 60 ℃ or higher, more preferably 70 ℃ or higher, from the viewpoint of further improving the effect of the present invention, because an optimum temperature is selected depending on the material of the capsule wall of the microcapsule to be used. The upper limit is not particularly limited, but is at most 180 ℃ or lower, and from the viewpoint of further improving the color development intensity, it is preferably 140 ℃ or lower, and more preferably 120 ℃ or lower.
The heating time is not particularly limited, but is preferably 1.0 to 20 minutes, and more preferably 3.0 to 10 minutes, from the viewpoint of further improving the effect of the present invention and from the viewpoint of productivity.
In the layer 1 obtained by the above method, the pits of the specific microcapsules are easily located on the side opposite to the support side as described above.
That is, the method for manufacturing the pressure-measuring sheet set of the present invention preferably includes the steps of applying a 1 st layer-forming composition containing microcapsules containing a color former, and subjecting the obtained coating film to a heat treatment at 60 ℃ or higher to form the 1 st layer. In the above step, it is preferable to produce a 1 st sheet including the 1 st layer, and combine the 1 st sheet obtained and a 2 nd sheet produced by the procedure described later to produce a pressure-measuring sheet set.
In addition, although the method of forming the 1 st layer on the 1 st support has been described above, the method is not limited to the above-described embodiment, and for example, the 1 st layer may be formed on the temporary support and then the temporary support may be peeled off to form the 1 st sheet composed of the 1 st layer.
The temporary support is not particularly limited as long as it is a releasable support.
< other Components >
The 1 st sheet may have other members than the 1 st support and the 1 st layer described above.
For example, the 1 st sheet may have an easy-adhesion layer between the 1 st support and the 1 st layer for improving adhesion therebetween.
The thickness of the easy adhesion layer is not particularly limited, but is preferably 0.005 to 0.2. mu.m, and more preferably 0.01 to 0.1. mu.m.
The arithmetic average roughness Ra of the 1 st sheet is not particularly limited, but is usually 0.1 μm or more, and preferably 2.5 to 7.0 μm from the viewpoint of further improving the effect of the present invention and the viewpoint of further improving the color development intensity. The arithmetic average roughness Ra of the 1 st sheet means the arithmetic average roughness Ra of the surface of the 1 st sheet on the side (side in contact with) facing the 2 nd sheet when the pressure measurement sheet set is used. In the case where the 1 st layer is positioned on the outermost surface of the 1 st sheet on the side facing the 2 nd sheet, the arithmetic average roughness Ra corresponds to the arithmetic average roughness Ra of the surface on the side opposite to the 1 st support side of the 1 st layer.
The arithmetic average roughness Ra (the arithmetic average roughness Ra of the 1 st sheet and the arithmetic average roughness Ra of the 2 nd sheet described later) in the present specification means a roughness measured by JIS B0681-6: 2014 the arithmetic mean roughness Ra. In addition, as a measuring apparatus, a scanning type white light interferometer using a light interference system (specifically, NewView5020 manufactured by Zygo corporation; Objective lens X50 times; intermediate lens X0.5 times) was used. The measurement mode for measuring the arithmetic average roughness Ra of the 1 st sheet by using the scanning white light interferometer was the Stich mode, and the measurement mode for measuring the arithmetic average roughness Ra of the 2 nd sheet was the Micro mode.
< 2 nd sheet >
The 2 nd sheet 22 shown in fig. 1 includes a 2 nd support 18 and a 2 nd layer 20 containing a color developer and disposed on the 2 nd support 18.
Hereinafter, each member will be described in detail.
< No. 2 support >
The 2 nd support is a member for supporting the 2 nd layer. In addition, in the case of being able to be handled by the 2 nd layer itself, the 2 nd sheet may not have the 2 nd support.
The mode of the 2 nd support body is the same as that of the 1 st support body described above, and therefore, the description thereof is omitted.
< layer 2 >
The 2 nd layer is a layer containing a developer.
The developer is a compound which does not have a color-developing function but has a property of developing a color of a color-developing agent by contacting the color-developing agent. The developer is preferably an electron-accepting compound.
The color-developing agent includes inorganic compounds and organic compounds, and preferably inorganic compounds and organic compounds described in paragraphs 0055 to 0056 of International publication No. 2009/008248. From the viewpoint of further improving the color development density and the image quality after color development, acid clay, activated clay, or a metal salt of an aromatic carboxylic acid is preferable.
The content of the color-developing agent in the 2 nd layer is not particularly limited, and is preferably 20 to 95% by mass, more preferably 30 to 90% by mass, based on the total mass of the 2 nd layer, from the viewpoint of further improving the effect of the present invention.
The color-developing agent may be used alone in 1 kind, or may be used in combination in 2 or more kinds.
The content of the color-developing agent in the 2 nd layer is not particularly limited, but is preferably 0.1 to 30g/m 2 . When the color developing agent is an inorganic compound, the content of the color developing agent is preferably 3 to 20g/m 2 More preferably 5 to 15g/m 2 . When the developer is an organic compound, the content of the developer is preferably 0.1 to 5g/m 2 More preferably 0.2 to 3g/m 2 。
The 2 nd layer may contain other components than the above-described developer.
Examples of the other components include a polymer binder, a pigment, a fluorescent whitening agent, an antifoaming agent, a penetrant, an ultraviolet absorber, a surfactant, and a preservative.
Examples of the polymer binder include synthetic polymers and natural polymers such as styrene-butadiene copolymers, polyvinyl acetate, polyacrylates, polyvinyl alcohol, polyacrylic acid, maleic anhydride-styrene copolymers, olefin resins, modified acrylate copolymers, starch, casein, gum arabic, gelatin, carboxymethyl cellulose or salts thereof, and methyl cellulose.
Examples of the pigment include ground calcium carbonate, light calcium carbonate, talc, and titanium dioxide.
The thickness of the 2 nd layer is not particularly limited, but is preferably 1 to 50 μm, more preferably 2 to 30 μm, from the viewpoint of further improving the effect of the present invention.
And, the mass per unit area (g/m) of the 2 nd layer 2 ) Although not particularly limited, from the viewpoint of further improving the effect of the present invention, it is preferably 0.5 to 30g/m 2 。
< method for forming layer 2 >
The method for forming the 2 nd layer is not particularly limited.
For example, a method may be mentioned in which the composition for forming the layer 2 containing a color-developer is applied to the support 2 and the obtained coating film is dried as necessary.
The composition for forming the 2 nd layer may be a dispersion liquid in which a developer is dispersed in water or the like. In the case where the developer is an inorganic compound, a dispersion liquid in which the developer is dispersed can be prepared by mechanically dispersing the inorganic compound in water. When the developer is an organic compound, the developer can be prepared by mechanically dispersing the organic compound in water or dissolving the organic compound in an organic solvent.
The composition for forming the layer 2 may contain other components that may be contained in the layer 2.
The method of applying the composition for forming the 2 nd layer is not particularly limited, and a method using a coater used for applying the composition for forming the 1 st layer is exemplified.
After the composition for forming the layer 2 is applied to the support 2, the coating film may be dried as necessary. The drying treatment may be a heating treatment.
Although the method of forming the 2 nd layer on the 2 nd support has been described above, the method is not limited to the above-described method, and for example, the 2 nd layer may be formed on the temporary support and then the temporary support may be peeled off to form the 2 nd sheet composed of the 2 nd layer.
The temporary support is not particularly limited as long as it is a releasable support.
< other Components >
The 2 nd sheet may have other members than the 2 nd support and the 2 nd layer described above.
For example, the 2 nd sheet may have an easy-adhesion layer between the 2 nd support and the 2 nd layer for improving adhesion therebetween.
Examples of the easy adhesion layer include those which the above-mentioned 1 st sheet may have.
As described above, the 1 st sheet and the 2 nd sheet are used by laminating the 1 st sheet and the 2 nd sheet so that the 1 st layer of the 1 st sheet and the 2 nd layer of the 2 nd sheet face each other to obtain a laminate, and pressing the laminate.
From the viewpoint of further improving the effect of the present invention and the color development density, the arithmetic average roughness Ra of the 2 nd sheet is preferably 1.2 μm or less. The arithmetic average roughness Ra of the 2 nd sheet is the arithmetic average roughness Ra of the surface of the 2 nd sheet on the side (side in contact with) facing the 1 st sheet when the pressure measurement sheet set is used. When the 2 nd layer is positioned on the outermost surface of the 2 nd sheet on the side facing the 1 st sheet, the arithmetic average roughness Ra corresponds to the arithmetic average roughness Ra of the surface on the side opposite to the 2 nd support side of the 2 nd layer.
[2 nd embodiment ]
Fig. 6 is a cross-sectional view of an embodiment of a pressure-measuring sheet.
The pressure-measuring sheet 30 includes a support 32, a 2 nd layer 20 containing a developer, and a 1 st layer 14 containing microcapsules in this order. Layer 1 contains specific microcapsules as described above.
When the pressure-measuring sheet 30 is used, the microcapsules are broken in the pressurized region by applying pressure from at least one of the support 32 side and the 1 st layer 14 side, and the color former contained in the microcapsules comes out from the microcapsules to perform a color development reaction with the color developer in the 2 nd layer 20. As a result, color development proceeds in the pressurized region.
As described later, the pressure-measuring sheet 30 may have the 1 st layer 14 and the 2 nd layer 20, or may not have the support 32.
In fig. 6, the support 32 and the 2 nd layer 20 are directly laminated, but the present invention is not limited to this embodiment, and another layer (for example, an easy adhesion layer) may be disposed between the support 32 and the 2 nd layer 20 as described later.
Further, although the pressure measurement sheet 30 having the support 32, the 2 nd layer 20, and the 1 st layer 14 in this order is disclosed in fig. 6, the present invention is not limited to this embodiment, and a pressure measurement sheet having the support 32, the 1 st layer 14, and the 2 nd layer 20 in this order may be used.
The 1 st layer 14 and the 2 nd layer 20 in the pressure-measuring sheet 30 are the same members as the 1 st layer 14 and the 2 nd layer 20 described in the above-described embodiment 1, and therefore, description thereof is omitted.
Hereinafter, the support 32 will be mainly described in detail.
Support
The support is a member for supporting the 1 st and 2 nd layers. In the case where the laminate itself of the 1 st and 2 nd layers can be handled, the pressure-measuring sheet may not have a support.
The preferred embodiment of the support is the same as that of the above-described 1 st support, and therefore, the description thereof is omitted.
Method for producing pressure measuring sheet
The method for producing the pressure-measuring sheet is not particularly limited.
For example, the following methods may be mentioned: the layer-forming composition for layer 2 containing a developer is applied to a support and, if necessary, dried, and after the layer 2 is formed on the support, the layer-forming composition for layer 1 containing microcapsules is further applied to the layer 2 and the obtained coating film is subjected to heat treatment at a predetermined temperature to form the layer 1.
The method for forming the 1 st layer using the 1 st layer forming composition is as described in embodiment 1. The method for forming the 2 nd layer using the composition for forming the 2 nd layer is also as described in embodiment 1.
That is, the method for producing a pressure-measuring sheet of the present invention preferably includes, in the same manner as the method for producing the pressure-measuring sheet set, the step of applying a 1 st layer-forming composition containing microcapsules containing a color former, and subjecting the obtained coating film to a heat treatment at 60 ℃ or higher to form the 1 st layer. Thus, for example, the pressure-measuring sheet may be prepared by applying the composition for forming the layer 2 containing the color-developer to a support, and if necessary, drying the composition to form the layer 2 on the support, and then performing the above-described steps.
Other parts
The pressure-measuring sheet may include other members besides the support, the 2 nd layer, and the 1 st layer.
For example, the pressure-measuring sheet may have an easy-adhesion layer between the support and the 2 nd layer for improving adhesion therebetween.
Examples of the easy adhesion layer include those which the above-mentioned 1 st sheet may have.
As described above, the pressure measurement sheet is used by pressing the surface thereof.
In addition, when the pressure-measuring sheet includes a support, it is preferable that the specific microcapsules in the layer 1 have pits on the side opposite to the support side from the viewpoint of further improving the effect of the present invention.
Examples
The present invention will be described in further detail below with reference to examples. The materials, the amounts used, the ratios, the contents of the treatments, the procedures of the treatments, and the like shown in the following examples can be appropriately changed 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. Unless otherwise specified, "parts" and "%" are based on mass.
[ example 1]
< preparation of microcapsules containing color former therein >
3 ', 6' -bis (diethylamino) -2- (4-nitrophenyl) spiro [ isoindole-1, 9 '-xanthen ] -3-one (manufactured by Hodgaya Chemical Co., Ltd., Pink-DCF)3 parts, 6' - (diethylamino) -1 ', 3' -dimethylfluoran precursor (Hodgaya Chemical Co., Ltd., ltd. manufacture, Orange-DCF)4 parts, thereby obtaining solution a. Next, 13 parts of N, N' -tetrakis (2-hydroxypropyl) ethylenediamine (ADEKA CORPORATION, ADEKA polymer EDP-300) dissolved in synthetic isoalkane (Idemitsu Kosan co., ltd., IP Solvent 1620) and 2.5 parts of methyl ethyl ketone were added to the stirred solution a, thereby obtaining a solution B. Further, 2.5 parts of a trimethylolpropane adduct of toluene diisocyanate (DIC CORPORATION, BURNOCK D-750) dissolved in 6 parts of ethyl acetate was added to the stirred solution B to obtain a solution C. Then, the solution C was added to a solution prepared by dissolving 7 parts of polyvinyl alcohol (PVA-217E, Kuraray co., Ltd.) in 140 parts of water, and emulsified and dispersed. To the emulsified liquid after the emulsification and dispersion, 200 parts of water was added, and the mixture was heated to 70 ℃ while stirring, and then cooled after stirring for 1 hour. Further, water was added to adjust the concentration, thereby obtaining a microcapsule liquid containing a color former at a solid content concentration of 20%.
The average particle diameter of the obtained microcapsules containing a color former was 20 μm. The average particle diameter was measured by an optical microscope and by the method described above.
[ production of sheet set for pressure measurement ]
(preparation of the 1 st sheet)
The obtained microcapsule liquid containing a color former inside, 10 parts of water, 1.8 parts of colloidal silica (Nissan Chemical Industries, ltd., SNOWTEX 30, solid content 30%), 2 parts of a 1% aqueous solution of sodium carboxymethylcellulose (DKS co.ltd., SEROGEN 5A), 4.5 parts of a 1% aqueous solution of sodium carboxymethylcellulose (DKS co.ltd., SEROGEN EP), 1 part of a 15% aqueous solution of a side chain alkylbenzenesulfonic acid amine salt (DKS co.ltd., NEOGEN T), 0.2 parts of a 1% aqueous solution of polyoxyethylene polyoxypropylene lauryl ether (DKS co.ltd., nonogen LP-70), and 0.2 parts of a 1% aqueous solution of sodium-bis (3,3,4,4,5,5,6,6, 6-nonafluorohexyl) -2-sulfonyloxyoctanoic acid (fujim film, W-AHE) were mixed to obtain a 1% aqueous solution for forming a coating liquid for a layer 1 st coating liquid for a coating.
The obtained composition for forming the 1 st layer was applied to a polyethylene terephthalate (PET) sheet having a thickness of 75 μm by a bar coater so that the dried mass became 6.0g/m 2 . Next, the obtained coating film was heated at 80 ℃ for 5 minutes to form a 1 st layer, thereby producing a 1 st sheet.
In addition, fig. 7 is an enlarged photograph of layer 1 observed by a scanning electron microscope, and as shown in fig. 7, the microcapsules in layer 1 have pits.
(preparation of No. 2 sheet)
To the resulting dispersion were added 100 parts of activated clay (Mizusawa Industrial Chemicals, Ltd., Shilton F-242) as a color developer, 0.5 parts of Na hexametaphosphate (Nippon Chemical Industry Co., Ltd., sodium hexametaphosphate), 15 parts of 10% aqueous sodium hydroxide solution, and 240 parts of water, and mixed were 30 parts of an olefin resin (ARAKAWA CHEMICAL INDUSTRIES, LTD., Polymaron 482, solid content concentration 25 mass%), 35 parts of a modified acrylate copolymer (Zecorporation, Nippon LX814, solid content concentration 46 mass%), 80 parts of a 1% aqueous solution of sodium carboxymethylcellulose (DKS Co. Ltd., SEROGEN EP), 18 parts of a 15% aqueous solution of Na alkylbenzenesulfonate (DKS Co. Ltd., NEOGEN) 18 parts of a polyoxyethylene polyoxypropylene lauryl ether (DKS Co. Ltd., NOIGEN LP-70), 1% aqueous solution of sodium bis (3-5, 3-4, 3-5, 6, 3-5, 6-hexyl octanoate, 6-6 parts of fluorine sulfonate (FIS Co., LTS. TM., LTS. RTM., LTD., LTS. TM., LTS Co., LTS.E, SEROGEN, 2,4 mass%, and 5 mass%, 6, and 35 mass%, and 35 parts of water were added to the color developer as a developer, W-AHE) was added to 20 parts of a 1% aqueous solution to prepare a 2 nd layer forming composition containing a developer.
The layer-forming composition 2 containing a developer was coated on a PET sheet having a thickness of 75 μm so that the amount of solid matter applied was 7.0g/m 2 . Next, the obtained coating film was dried to form a 2 nd layer, thereby obtaining a 2 nd sheet.
[ examples 2 to 9, comparative example 1]
A 1 st sheet and a 2 nd sheet were produced in the same manner as in example 1 except that the number average wall thickness, δ/Dm, the heating temperature for forming the 1 st layer, and the mass of the 1 st layer after drying were changed as shown in table 1 described later.
The number average wall thickness of the microcapsules was changed by adjusting the amount of trimethylolpropane adduct of N, N, N ', N' -tetrakis (2-hydroxypropyl) ethylenediamine (ADEKA CORPORATION, ADEKA POLYETHER EDP-300) and toluene diisocyanate (DIC CORPORATION, BURNOCK D-750).
In addition, in comparative example 1, no specific microcapsule was observed.
[ measurement and evaluation ]
[ scratch resistance ]
A2 nd sheet cut into 10cm X20 cm was fixed to a smooth glass plate of 15cm X25 cm so that the 2 nd surface faced upward (the PET sheet was brought into contact with the glass plate). On this, a 1 st sheet cut to 5cm × 5cm was stacked with the 1 st layer facing downward (so that the 1 st layer was in contact with the 2 nd layer). The 1 st sheet was reciprocated 5 times by 5cm horizontally at a speed of 3 m/min while applying a load of 0.001MPa to the 1 st sheet. Then, the two superposed sheets were peeled off, and the concentration (DA) of the color-developed part formed on the 2 nd sheet was measured from the support (PET sheet) surface side using a densitometer RD-19 (manufactured by X-Rite Inc).
Separately from this, the initial concentration (DB) of the unused 2 nd sheet was measured from the support (PET sheet) surface side using a concentration meter RD-19 (manufactured by X-Rite Inc).
Then, color development concentration Δ D1 was obtained by subtracting initial concentration DB from concentration DA, and evaluated according to the following evaluation criteria. "B" is a range that can be practically allowed.
"A": Δ D1 was 0.00 (no color development due to rubbing was observed).
"B": Δ D1 was more than 0.00 and not more than 0.01 (color development due to friction was slightly observed).
"C": Δ D1 was more than 0.01 (color development due to rubbing was clearly observed).
[ evaluation of color development Density ]
Using the 1 st sheet and the 2 nd sheet prepared in each example and comparative example, evaluation of the pressure measurement sheet set was performed. Specifically, the 1 st sheet and the 2 nd sheet cut to a size of 5cm × 5cm were stacked so that the surface of the 1 st layer of the 1 st sheet and the surface of the 2 nd layer of the 2 nd sheet were in contact with each other, to obtain a laminate. Subsequently, the laminate was pressed by a press (DSF-C1-A, AIDA ENGINEERING, LTD.) under a pressure of 1.0MPa to develop color. Thereafter, the 1 st and 2 nd sheets constituting the laminate were peeled off, and the concentration (DA) of the color-developing part formed on the 2 nd sheet was measured from the support (PET sheet) surface side using a densitometer RD-19 (manufactured by X-Rite Inc).
Separately from this, the initial concentration (DB) of the unused 2 nd sheet was measured from the support (PET sheet) surface side using a concentration meter RD-19 (manufactured by X-Rite Inc).
Then, color development concentration Δ D2 was obtained by subtracting initial concentration DB from concentration DA, and evaluated according to the following evaluation criteria. "B" is a range that can be practically allowed.
"A": Δ D2 was 0.7 or more (color development was clearly observed).
"B": Δ D2 was 0.2 or more and less than 0.7 (slightly color development was observed).
"C": Δ D2 was less than 0.2 (little color development was observed).
The measurement methods of the number average wall thickness (μm) of the microcapsules, the average particle diameter (μm) of the microcapsules, and the glass transition temperature of the capsule wall of the microcapsules are as described above.
The method of measuring the arithmetic average roughness Ra of the 1 st sheet (corresponding to the arithmetic average roughness Ra of the surface opposite to the PET sheet side of the 1 st layer) and the arithmetic average roughness Ra of the 2 nd sheet (corresponding to the arithmetic average roughness Ra of the surface opposite to the PET sheet side of the 2 nd layer) was also as described above.
The method of measuring the average value of the ratio (distance H/maximum length L) of the specific microcapsules was also evaluated in accordance with the following evaluation criteria, as described above.
In examples 1 to 9, microcapsules having pits were observed in the layer 1, and the pits of the microcapsules having pits were located on the opposite side of the support.
In table 1, "capsule wall thickness [ μm ]" represents the number average wall thickness (μm) of the microcapsules.
In table 1, "average particle diameter [ μm ]" represents the average particle diameter (μm) of the microcapsule.
In "δ/Dm" in table 1, δ represents the number average wall thickness (μm) of the microcapsule, and Dm represents the average particle diameter (μm) of the microcapsule.
In Table 1, "heating temperature (. degree. C.)" represents the heating temperature at the time of forming the 1 st layer.
In Table 1, "mass after drying (g/m) 2 ) "means the dried mass (g/m) of the 1 st layer 2 )。
In table 1, "H/L" represents a ratio of a distance H from the bottom of the pit of the specific microcapsule to the outer surface of the capsule wall facing the pit to a maximum length L of the specific microcapsule in a direction orthogonal to the depth direction (pit direction) of the pit of the specific microcapsule.
In table 1, "W/L" represents a ratio of the maximum width W of the opening of the dimple of the specific microcapsule to the maximum length L.
In table 1, "D/H" represents a ratio of a depth D (depth of a pit) from an opening of a pit of a specific microcapsule to a bottom of the pit to the distance H.
In table 1, "ratio (%) of specific microcapsules" indicates a ratio (%) of specific microcapsules with respect to the total number of microcapsules. The measurement method is as described above.
[ Table 1]
As shown in table 1, it was confirmed that the desired effects were obtained when the pressure measurement sheet set of the present invention was used.
Among them, when the arithmetic average roughness Ra of the 1 st sheet is 2.5 to 7.0 μm as compared with examples 1 and 4 to 6, the color development due to friction is further suppressed and the color development density is further excellent.
From the comparison of examples 1 to 3 and 7 to 9, the color development due to friction was more suppressed and the color development intensity was more excellent than the average value of (H/L) of 0.5 to 0.9. Further, from the comparison of examples 1 to 3, 8 and 9, the relationship of formula (1) (0.100 > δ/Dm > 0.001) was satisfied, whereby the color development due to rubbing was further suppressed and the color development intensity was further excellent.
From the comparison of examples 1 to 3, 8 and 9, the number average wall thickness of the microcapsules exceeded 0.02 μm and was less than 2 μm, and the color development due to friction was further suppressed, and the color development intensity was further excellent.
In addition, although the above description shows the mode using the pressure measuring sheet set having the 1 st and 2 nd sheets, the pressure measuring sheets having the 2 nd and 1 st layers stacked in this order on the support were produced, and the same test results as those of the above were obtained, and the same results as those of the examples were obtained.
Specifically, the same results as in example 1 were obtained as a result of performing the above-described evaluations (scratch resistance evaluation, color development intensity evaluation) on the pressure-measuring sheet having the support, the 2 nd layer, and the 1 st layer, which were prepared in example 1, disposed on the polyethylene terephthalate sheet in this order, and performing the above-described evaluations (scratch resistance evaluation, color development intensity evaluation).
In addition, when the scratch resistance evaluation was performed using the pressure measurement sheet, the evaluation was performed by horizontally moving the pressure measurement sheet at a speed of 3 m/min by 5cm while applying a load of 0.001Mpa from the pressure measurement sheet.
Description of the symbols
10-set of sheets for pressure measurement, 12-support 1, 14-layer 1, 16-sheet 1, 18-support 2, 20-layer 2, 22-sheet 2, 24-specific microcapsules, 26-wells, 28-capsule walls, 30-sheet for pressure measurement, 32-support.
Claims (22)
1. A pressure measurement sheet set is provided with:
a 1 st sheet having a 1 st layer containing microcapsules containing a color former therein; and
a 2 nd sheet having a 2 nd layer containing a color developer,
at least a portion of the microcapsules having dimples in the capsule wall,
the ratio of the microcapsules having the pits with respect to the total number of the microcapsules is 20% or more.
2. The set of pressure-measuring sheets according to claim 1,
the average value of the ratio of the distance H from the bottom of the pit of the microcapsule having the pit to the outer surface of the capsule wall facing the pit to the maximum length L of the microcapsule having the pit in the direction orthogonal to the depth direction of the pit is 0.90 or less.
3. The set of pressure-measuring sheets according to claim 2,
the average value of the ratio is 0.50 to 0.90.
4. The set of pressure-measuring sheets according to any one of claims 1 to 3,
the microcapsule having the pits has 1 pit.
5. The set of sheets for pressure measurement according to any one of claims 1 to 4,
the capsule wall of the microcapsule comprises at least 1 resin selected from polyurethaneurea, polyurethane and polyurea,
the glass transition temperature of the capsule wall is 50-160 ℃.
6. The set of sheets for pressure measurement according to any one of claims 1 to 5,
the microcapsules have a number average wall thickness of more than 0.02 [ mu ] m and less than 2 [ mu ] m.
7. The set of sheets for pressure measurement according to any one of claims 1 to 6,
the microcapsules satisfy the relationship of formula (1),
formula (1)0.100 & gt delta/Dm & gt 0.001
δ represents the number average wall thickness of the microcapsules in μm, and Dm represents the average particle diameter of the microcapsules in μm.
8. The set of sheets for pressure measurement according to any one of claims 1 to 7,
the arithmetic average roughness Ra of the 1 st sheet is 2.5-7.0 μm.
9. The set of sheets for pressure measurement according to any one of claims 1 to 8,
the arithmetic average roughness Ra of the 2 nd sheet is 1.2 [ mu ] m or less.
10. The set of sheets for pressure measurement according to any one of claims 1 to 9,
the 1 st sheet further has a support,
the pits of the microcapsules having the pits are located on the side opposite to the support side.
11. The set of pressure-measuring sheets according to claim 10,
the support is a resin film.
12. A pressure-measuring sheet comprising:
layer 1 comprising microcapsules containing a color former therein; and
a 2 nd layer disposed on the 1 st layer and containing a color developer,
at least a portion of the microcapsules having dimples in the capsule wall,
the ratio of the microcapsules having the pits with respect to the total number of the microcapsules is 20% or more.
13. The pressure-measuring sheet according to claim 12,
the average value of the ratio of the distance H from the bottom of the pit of the microcapsule having the pit to the outer surface of the capsule wall facing the pit to the maximum length L of the microcapsule having the pit in the direction orthogonal to the depth direction of the pit is 0.90 or less.
14. The pressure-measuring sheet according to claim 13,
the average value of the ratio is 0.50 to 0.90.
15. The sheet for pressure measurement according to any one of claims 12 to 14,
the microcapsule having the pits has 1 pit.
16. The set of sheets for pressure measurement according to any one of claims 12 to 15,
the capsule wall of the microcapsule comprises at least 1 resin selected from polyurethaneurea, polyurethane and polyurea,
the glass transition temperature of the capsule wall is 50-160 ℃.
17. The sheet for pressure measurement according to any one of claims 12 to 16,
the microcapsules have a number average wall thickness of more than 0.02 [ mu ] m and less than 2 [ mu ] m.
18. The sheet for pressure measurement according to any one of claims 12 to 17,
the microcapsules satisfy the relationship of formula (1),
formula (1)0.100 & gt delta/Dm & gt 0.001
δ represents the number average wall thickness of the microcapsules in μm, and Dm represents the average particle diameter of the microcapsules in μm.
19. The sheet for pressure measurement according to any one of claims 12 to 18, further comprising a support body,
the pits of the microcapsules having the pits are located on the side opposite to the support side.
20. The pressure-measuring sheet according to claim 19,
the support is a resin film.
21. A method for manufacturing the pressure measurement sheet set according to any one of claims 1 to 11, comprising:
a composition for forming layer 1 containing microcapsules containing a color former is applied, and the obtained coating film is subjected to a heat treatment at 60 ℃ or higher to form layer 1.
22. A method for producing the pressure-measuring sheet according to any one of claims 12 to 20, comprising the steps of:
a composition for forming layer 1 containing microcapsules containing a color former is applied, and the obtained coating film is subjected to a heat treatment at 60 ℃ or higher to form layer 1.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2019225497 | 2019-12-13 | ||
| JP2019-225497 | 2019-12-13 | ||
| PCT/JP2020/043998 WO2021117496A1 (en) | 2019-12-13 | 2020-11-26 | Pressure measurement sheet set, pressure measurement sheet, method for manufacturing pressure measurement sheet set, and method for manufacturing pressure measurement sheet |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114829893A true CN114829893A (en) | 2022-07-29 |
Family
ID=76330180
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202080085495.6A Pending CN114829893A (en) | 2019-12-13 | 2020-11-26 | Pressure measurement sheet set, pressure measurement sheet, method for manufacturing pressure measurement sheet set, and method for manufacturing pressure measurement sheet |
Country Status (4)
| Country | Link |
|---|---|
| JP (1) | JP7100209B2 (en) |
| CN (1) | CN114829893A (en) |
| TW (1) | TW202128414A (en) |
| WO (1) | WO2021117496A1 (en) |
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| JP5658536B2 (en) | 2010-03-08 | 2015-01-28 | 日新製鋼株式会社 | Painted aluminized steel sheet |
| EP2460585B1 (en) * | 2010-12-03 | 2017-10-18 | Holcim Technology Ltd. | Microcapsule |
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2020
- 2020-11-26 WO PCT/JP2020/043998 patent/WO2021117496A1/en active Application Filing
- 2020-11-26 CN CN202080085495.6A patent/CN114829893A/en active Pending
- 2020-11-26 JP JP2021563845A patent/JP7100209B2/en active Active
- 2020-12-10 TW TW109143547A patent/TW202128414A/en unknown
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| JPS5658536A (en) * | 1979-10-08 | 1981-05-21 | Basf Ag | Manufacture of microocapsule* microocapsule obtained from said method and method using said capsule for pressure sensitive recording system |
| JPH07276807A (en) * | 1994-04-14 | 1995-10-24 | Fuji Photo Film Co Ltd | Multicolor thermal recording material and thermal recording method using the same |
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Also Published As
| Publication number | Publication date |
|---|---|
| WO2021117496A1 (en) | 2021-06-17 |
| JPWO2021117496A1 (en) | 2021-06-17 |
| TW202128414A (en) | 2021-08-01 |
| JP7100209B2 (en) | 2022-07-12 |
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