WO2019154148A1

WO2019154148A1 - Color-generating film having ridged structure, pressure test film and preparation method therefor

Info

Publication number: WO2019154148A1
Application number: PCT/CN2019/073336
Authority: WO
Inventors: 崔叶; 冉光念; 刘亚军
Original assignee: 保定乐凯新材料股份有限公司
Priority date: 2018-02-11
Filing date: 2019-01-28
Publication date: 2019-08-15
Also published as: KR102468052B1; CN108373548A; KR20200120697A; CN108373548B; JP7039732B2; JP2021513477A

Abstract

The present disclosure relates to a color-generating film and a pressure test film, the color-generating film comprising: a substrate on which other layers are coated so as to form the color-generating film; a ridged structure layer which is formed on the substrate; and a color-generating layer which is coated on the ridged structure layer and which comprises microcapsules, the microcapsules containing an electron-donating colorless dye precursor, and the electron-donating colorless dye contacting an electron-accepting compound and thus having a color; when the color-generating film is pressed, the ridged structure layer presses the color-generating layer such that the microcapsules in the color-generating layer rupture to release the electron-donating colorless dye precursor. The color-generating film reduces the size and concentrates the pressure-receiving area of the pressure test film and the actual pressure-receiving area of the microcapsules by means of the ridged structure layer, therefore even if a small pressure is applied to the pressure test film, the pressure test film may have high sensitivity.

Description

Color film with uneven structure, pressure test film and preparation method thereof

Technical field

The present disclosure relates to a chromonic film and a pressure test film and a method of preparing the same, and more particularly to a chromonic film having a textured layer and a pressure test film and a method of preparing the same.

Background technique

The pressure test is mainly applied to various production processes such as lamination of printed circuit boards, confirmation and adjustment of pressure between rolls, lamination of liquid crystal glass panels, and assembly of engine cylinders, which have strict requirements on pressure. The pressure tester is usually used for stress test, but the pressure test method is complicated in operation, the measurement result is hysteresis, the test accuracy and sensitivity are poor, and it is only applicable to the pressure test in a small area, and is not suitable for online pressure monitoring, and is not applicable. Pressure test with special shaped areas.

To facilitate these pressure testing applications, pressure testing membranes have been used extensively. The pressure test film generally has a color developing portion containing a microcapsule, and a color developing portion containing an electron donating leuco dye precursor. The chromonic portion is under pressure to cause the microcapsules therein to rupture and release to the electronic leuco dye, and the electron-donating leuco dye contacts the electron-accepting compound to thereby color the color-developing portion, and then according to the coloring portion of the color-developing portion and The chromaticity or the like is used to determine the magnitude of the pressure, the point of stress, and the like.

However, the existing pressure test film cannot achieve a reduction in the pressure-receiving area of the pressure test film and the actual pressure-receiving area of the microcapsule. In actual use, it is necessary to rupture the microcapsules under a considerable pressure to release the electron leuco dye and contact the electron-accepting compound to form a color. Therefore, in the case of testing a small pressure using a pressure test film, it is difficult to perform a pressure test with high sensitivity.

Therefore, there is a need for a pressure test membrane that is capable of testing pressure under a low pressure test environment.

Summary of the invention

To this end, the present disclosure adds a layer of uneven structure between the coloring layer of the pressure test film and the substrate to reduce the pressure-receiving area of the pressure test film and the actual pressure-receiving area of the microcapsule, thereby realizing the pressure test film. High sensitivity.

Specifically, according to an aspect of the present disclosure, a chromonic film is provided, comprising: a substrate for coating other layers thereon to form a chromonic film; and a textured layer formed on the substrate And a chromonic layer coated on the textured layer and comprising microcapsules containing an electron-donating leuco dye precursor, the electron-donating leuco dye contacting the electron-accepting compound to be colored, Wherein when the chromonic film is pressed, the relief structure layer presses the chromonic layer such that the microcapsules in the chromonic layer rupture and are released to the electron leuco dye precursor.

Preferably, the chromonic film further comprises an undercoat layer between the substrate and the relief structure layer for stably supporting the relief structure layer on the substrate.

Preferably, the concave-convex structure layer has at least two convex portions, and a linear distance L between the tips of the adjacent two convex portions satisfies the following relationship: D50×0.2≤L≤D50×0.8, where D50 represents the micro The particle size corresponding to the cumulative particle size distribution of the capsule reached 50%.

Preferably, the uneven structure layer is formed of a UV resin.

Preferably, the convex shape on the concave-convex structure layer is a cylinder, a cone, a rectangular parallelepiped or a square.

Preferably, the top of the protrusion on the relief structure layer is pointed.

Regarding the manner in which the uneven structure layer is formed, reference can be made to the same Japanese application of the applicant's invention titled "Concave-convex structure preparation equipment".

Preferably, the undercoat layer is formed by coating with an aqueous resin, preferably a polyvinyl alcohol or a styrene-butadiene copolymer latex-based aqueous resin.

According to another aspect of the present disclosure, there is provided a pressure test film comprising: a chromonic film layer comprising the chromonic film as described above; and a chromogenic film layer containing the chromonic film layer A color developing material for an electronic compound.

According to still another aspect of the present disclosure, there is provided a method of preparing the chromonic film, comprising: forming a textured layer by adding a reactive diluent to a UV resin and stirring uniformly, adding a photoinitiator or an auxiliary agent, and stirring uniformly Slurry; by arranging the oil phase and the aqueous phase containing the electron-donating leuco dye precursor, adding the oil phase to the water phase by a membrane emulsification method to form an emulsion, adding a curing agent to stir evenly, and heating to 50 ° C for 4 hours after the reaction Forming a microcapsule dispersion, adding a binder and water and stirring to form a chromonic layer slurry; and sequentially coating the uneven structure layer slurry and the chromonic layer slurry on the substrate to obtain a pressure test A chromonic film for the film.

According to another aspect of the present disclosure, there is provided a method of preparing the pressure test film comprising: forming a textured layer by adding a reactive diluent to a UV resin and stirring uniformly, adding a photoinitiator or an auxiliary agent, and stirring uniformly Slurry; by arranging the oil phase and the aqueous phase containing the electron-donating leuco dye precursor, adding the oil phase to the water phase by a membrane emulsification method to form an emulsion, adding a curing agent to stir evenly, and heating to 50 ° C for 4 hours after the reaction The microcapsule dispersion is prepared, and then the binder and water are added and stirred to form a chromonic layer slurry; the activated clay is added to water and stirred for pre-dispersion, and then sanded by an abrasive mill to form an active white clay water dispersion. Liquid, adding a binder and stirring to form a color developing layer slurry; sequentially coating the uneven structure layer slurry and the coloring layer slurry on the substrate to obtain a color developing film usable for the pressure test film, and in the substrate The color developing layer slurry is coated to obtain a color developing film usable for the pressure test film; and the color developing film and the color developing film are combined into the pressure test film.

The pressure test film of the present disclosure overlaps the chromonic film material L and the chromogenic film material K in a relative manner with the coating during use, and is placed between the pressure receiving surfaces, and when the microcapsules are pressed more than the breaking threshold value thereof Disrupting, releasing an electron-donating leuco dye, which is in contact with an electron-accepting compound contained in the color developing film material K, undergoes a color forming reaction, and can be completed by observing and measuring the concentration depth of the color forming region. Test of stress. Because it is pressure tested by the color-forming principle of electron-donating leuco dyes and electron-accepting compounds, it has high sensitivity, high resolution, and can meet the requirements of low temperature environment, especially 5 °C-15 °C environment.

Moreover, the pressure test film of the present disclosure can reduce the pressure-receiving area of the pressure test film and the actual pressure-receiving area of the microcapsule by using the uneven structure layer between the color-developing layer and the undercoat layer. According to the pressure conversion formula P=F/S, under the same pressure, when the force area is reduced, the actual pressure of the microcapsules is increased, and when the actual pressure is greater than the critical value, the microcapsules are broken and released to the electrons. The dye is colored and contacts the electron-accepting compound to form a color. Therefore, even if a small pressure is applied to the pressure test film, high sensitivity of the pressure test film can be achieved.

DRAWINGS

The present disclosure will now be described by way of example, with reference to the accompanying drawings

1 is a schematic structural view of a chromonic film material L according to an embodiment of the present disclosure;

2 is a schematic structural view of a pressure test film according to an embodiment of the present disclosure;

3 is a flow chart of a method of preparing a chromonic film according to an embodiment of the present disclosure;

4 is a flow chart of a method of preparing a pressure test film in accordance with an embodiment of the present disclosure.

Detailed ways

The detailed description of the specific embodiments of the present disclosure is to be understood by the following description of the invention. Other examples, features, aspects, embodiments and advantages of the present disclosure will become apparent from the following description. It should also be understood that any one or more of the concepts, expressions, embodiments, examples, and the like described in this disclosure may be in other concepts, expressions, embodiments, examples, etc., as described in this disclosure. Any one or more of the combinations. Therefore, the teachings, expressions, examples, examples, and the like described below should not be considered as being independent of each other.

In addition, the illustrations in the drawings are not necessarily drawn to scale, and in some cases, the features of the present disclosure may be enlarged or reduced in the drawings to facilitate understanding of the present disclosure. Moreover, in the figures, like reference characters generally refer to the same features.

1 is a schematic structural view of a chromonic film according to an embodiment of the present disclosure. As shown in FIG. 1, the chromonic film provided by the present disclosure is made of a chromonic film material L, and the chromonic film material L is composed of a chromonic film substrate 213, an undercoat layer 215, a textured layer 217, and a coloring layer 219. composition. The undercoat layer 215, the uneven structure layer 217, and the coloring layer 219 are sequentially applied and adhered to the chromonic film substrate 213. The structure and function of the undercoat layer 215, the relief structure layer 217, and the coloring layer 219 will be described in more detail below.

2 is a schematic structural view of a pressure test film according to an embodiment of the present disclosure. As shown in FIG. 2, the pressure test film provided by the present disclosure is composed of a chromonic film layer containing a chromonic film material L and a color developing film layer containing a chromogenic film material K. The constitution of the color developing film material L is as described above, and the color developing film material K is composed of the color developing film substrate 223 and the color developing layer 225. The pressure test film is formed by overlapping the coloring layer 219 of the color developing film so as to face the coloring layer 225 of the color developing film. It should be noted that the chromonic film material L and the chromogenic film material K may not be formed into a pressure test film at the time of manufacture, but may be separately manufactured and sold as a separate film, that is, a chromonic film and a chromogenic film, and in application. In the case where the coloring film and the color developing film are overlapped with the coloring layer 219 of the coloring film and the coloring layer 255 of the color developing film, a structure such as a pressure test film is formed (hereinafter, for the sake of explanation, it is still called Test the film for pressure).

In addition, when the pressure test film is applied, a pressure P is applied between the photographic film pressure receiving surface 211 and the chromizing film pressure receiving surface 221, so that the microcapsules in the chromonic film are released by electron force release. The color dye, when the electron-donating leuco dye meets with the electron-accepting compound in the color-developing layer, and then determines the pressure P according to the degree of color formation, thereby achieving the purpose of testing the pressure using the pressure test film.

The substrate described herein includes a substrate 213 of a chromonic film and a substrate 223 of a chromogenic film. In an embodiment of the present disclosure, a substrate suitable for the present disclosure may be selected from a substrate such as a plastic film, paper, synthetic paper, or the like. Specific examples of the plastic film include polyethylene terephthalate (PET), polyethylene (PE), polypropylene (PP), and polyvinyl chloride (PVC). Specific examples of the paper include high quality paper, coated paper, art paper, and the like. Specific examples of the synthetic paper include synthetic papers formed of synthetic fibers such as polyethylene, polyamide, and polyethylene terephthalate, or synthetic papers obtained by laminating them on one or both sides of paper. Paper, etc. The present disclosure preferably has a PET of 50-125 [mu]m.

In an embodiment in accordance with the present disclosure, the undercoat layer 215 functions to improve adhesion of the textured structure layer 217 on the chromonic film substrate 213. The undercoat layer 215 is usually composed of one or more aqueous resins including styrene-butadiene copolymer latex (SBR), acrylate latex, polyvinyl alcohol (PVA), gelatin, carboxymethyl group. A synthetic or natural polymeric substance such as cellulose (CMC). The present disclosure is preferably PVA and SBR.

In an embodiment in accordance with the present disclosure, the relief structure layer 217 functions to apply pressure to the microcapsules in the chromonic layer 219 after the pressure applied to the surface of the pressure test film is converted by area. The textured structure layer 217 is composed of a UV resin, a reactive diluent, and a photoinitiator.

In an embodiment according to the present disclosure, the UV resin in the uneven structure layer 217 is composed of two or more of the following UV resins, and the UV resin suitable for the present disclosure includes, but is not limited to, urethane acrylate, ring Oxy acrylate, aliphatic urethane acrylate, and the like. The reactive diluent in the textured structure layer 217 is composed of two or more of the following reactive diluents, including but not limited to difunctional monomers such as tripropylene glycol diacrylate (TPGDA), dipropylene glycol double Acrylate (DPGDA), trifunctional monomers such as pentaerythritol triacrylate (PET3A), trimethylolpropane triacrylate (TMPTA), polyfunctional monomers such as dipentaerythritol hexaacrylate (DPHA), pentaerythritol tetraacrylate Ester (PET4A) and the like. Photoinitiators include, but are not limited to, 1-hydroxycyclohexyl phenyl ketone (184), 2,4,6-trimethylbenzoyl-diphenylphosphine oxide (TPO), 2-methyl-1-[ 4-Methylthiophenyl]-2-morphinyl-1-propanone (907) and the like.

In an embodiment according to the present disclosure, the uneven structure layer 217 is disposed on the undercoat layer 215, and the uneven portion of the uneven structure layer 217 has at least two convex portions, and two adjacent convex portions The linear distance L between them satisfies D50X0.2 ≤ L ≤ D50X0.8. When L<D50X0.2, because the spacing between adjacent convex portions is too small, the force area of the microcapsules cannot be effectively concentrated, and the pressure distribution under micro-pressure conditions cannot be measured. If L>D50X0.8, most of the microcapsules The pressure distribution measurement cannot be achieved because it is trapped in the gap between the adjacent convex portions and cannot be broken when the pressure is applied.

In an embodiment in accordance with the present disclosure, the shape of the protrusion in the relief structure layer 217 includes, but is not limited to, a shape of a cylinder, a cone, a cuboid, a cube, or the like.

In an embodiment in accordance with the present disclosure, the top of the protrusion in the relief structure layer 217 is tip-shaped.

In one embodiment in accordance with the present disclosure, the chromonic layer 219 comprises microcapsules, a binder, and an adjuvant comprising an electron donating leuco dye precursor. In one embodiment in accordance with the present disclosure, the microcapsules of the present disclosure comprise at least two portions of an electron donating leuco dye precursor solution and a microcapsule wall.

(electron leuco dye precursor solution)

In an embodiment in accordance with the present disclosure, the electron donating leuco dye precursor solution comprises at least one electron donating leuco dye precursor and at least one solvent. The role of the electron donating leuco dye precursor is the primary coupler. As the electron-donating leuco dye precursor, a known one can be used, such as a fluoran compound, a mercaptopeptide ketone compound, a rhodamine lactam compound, a spiropyran compound, or a phenothiazine compound. Electron-donating leuco dye precursors suitable for use in the present disclosure include, but are not limited to, crystal violet lactone (CVL), leuco methylene blue (BLMB).

The solvent mainly serves to dissolve the electron-donating leuco dye precursor, and a known one can be used. For example, diarylalkanes such as 1-phenyl-1-dimethylphenylethane, diaryl olefins, alkylnaphthalenes such as diisopropylnaphthalene, aliphatic hydrocarbons such as isoalkanes, and corn oil Natural animal and vegetable oils such as castor oil and rapeseed oil, mineral oil, etc.

In an embodiment according to the present disclosure, the electron-donating leuco dye precursor solution contains 3 parts to 12 parts of an electron-donating leuco dye precursor per 100 parts of the dye solution, if given If the electronic leuco dye precursor is less than 3 parts, the coloring concentration is insufficient. If the electron-donating leuco dye precursor is higher than 12 parts, the electron-donating leuco dye precursor crystallizes in a low temperature environment, resulting in effective development. The color component is reduced.

Further, in an embodiment according to the present disclosure, a solvent having a lower boiling point may be added as a co-solvent as needed to better dissolve the electron-donating leuco dye precursor in a solvent. Low boiling solvents suitable for use in the present disclosure include, but are not limited to, ketones such as acetone, methyl ethyl ketone, esters such as methyl acetate and ethyl acetate.

(microcapsule wall material)

In an embodiment according to the present disclosure, the wall material of the microcapsule may be a well-known water-insoluble and oil-insoluble substance such as polyurethaneurea, gelatin, melamine-formaldehyde resin, etc., and the present disclosure is preferably a polyurethaneurea.

The wall material of the microcapsules may be formed by a known method such as an interfacial polymerization method, an in-situ polymerization method, a coacervation method, or the like. In an embodiment in accordance with the present disclosure, it is preferred to form the wall material by interfacial polymerization.

In an embodiment in accordance with the present disclosure, the wall material consists at least of a reactive monomer and a curing agent. Suitable reactive monomers for the microcapsule wall material include, but are not limited to, dicyclohexylmethane diisocyanate (HDI), hexamethylene diisocyanate (HMDI), trimethylolpropane adduct of hexamethylene diisocyanate, benzene A polyisocyanate oligomer such as a trimethylolpropane adduct of dimethic acid diisocyanate. Curing agents suitable for the preparation of the microcapsule wall material include, but are not limited to, polyhydric hydroxy compounds such as aliphatic or aromatic polyols, polyamines such as triethylenetetramine, hexamethylenediamine, aliphatic polyamines, epoxy An alkane adduct such as a butylene oxide adduct of ethylenediamine may be used as long as it contains two or more -NH groups or -NH2 groups in the molecule. In one embodiment according to the present disclosure, the curing agent is preferably dissolved in water before use.

In an embodiment according to the present disclosure, the microcapsule particle size distribution is characterized by a particle size distribution D50 of 5 μm to 15 μm and a particle size distribution span of 0.5 to 1.2, where span=(D90-D10)/D50. If the D50 is less than 5 μm, the critical value of the microcapsule pressure is sharply increased, and the practical application range is limited, and most of the microcapsules may fall into the gap between the convex structures due to the small particle size, and thus cannot participate in color development. If D50 is more than 15 μm, the pressure test film coating apparently becomes uneven. If the span is less than 0.5, the manufacturing cost of the microcapsules increases sharply; if the span is larger than 1.2, the phenomenon of agglomeration of the size particles in the microcapsule system due to the difference in surface energy is prominent, which causes the pressure test film to cause coloration due to agglomeration during application. The density is uneven, resulting in reduced measurement accuracy.

(adhesives and additives)

In an embodiment according to the present disclosure, the binder in the coloring layer may be a water-soluble polymer such as starch, CMC, or PVA.

In one embodiment according to the present disclosure, the adjuvant comprises at least an emulsifier, including but not limited to an amphiphilic polymer such as PVA, CMC, starch, gelatin, etc., and PVA is preferred in the present disclosure.

In an embodiment of the present disclosure, the color developing layer 225 includes an electron accepting compound and a binder. In an embodiment of the present disclosure, the electron-accepting compound is a main color developing agent, and the electron-accepting compound may be a known electron-accepting compound including an inorganic compound such as activated clay, kaolin, clay, or the like. Substances, organic compounds such as: aromatic carboxylic acid metal salts, carboxylated terpene phenolic resin metal salts, phenolic resins, salicylates and derivatives thereof.

The function of the binder of the color developing layer 225 is to improve the adhesion of the electron-accepting compound to the color developing film substrate 223. The adhesive to which the color developing layer 225 of the present disclosure is applied is composed of one or more of the following water-soluble adhesives including, but not limited to, SBR, acrylate latex, PVA, gum arabic, gelatin, CMC, and the like.

3 is a flow chart of a method of preparing a chromonic film in accordance with an embodiment of the present disclosure. As shown in FIG. 3, according to an embodiment of the present disclosure, in step S310, various pastes used for producing a coloring film, that is, a coloring film material L, are prepared. The slurry includes at least an undercoat layer paste, a textured layer slurry, and a chromonic layer slurry. The step S310 comprises preparing an undercoat slurry to be used by dissolving the aqueous resin in water, adding an auxiliary agent and stirring uniformly. The step S310 further comprises forming a relief structure layer slurry to be used by adding a reactive diluent to the UV resin and stirring uniformly, adding a photoinitiator or an auxiliary agent and stirring. The step S310 further includes preparing the microcapsules and formulating the chromonic layer slurry, wherein the preparing the microcapsules comprises emulsification of the water-oil mixture and forming the microcapsule wall material. The oil phase is composed at least of the above-mentioned electron donating leuco dye precursor solution, a reaction monomer for synthesizing the microcapsule wall material, and the aqueous phase is composed of at least an emulsifier and water. The emulsification process may employ a known emulsification method such as a mechanical stirring emulsification method, a homogeneous emulsification method, a phacoemulsification method, a membrane emulsification method, or the like. In an embodiment according to the present disclosure, the emulsion is preferably prepared by a membrane emulsification method, and the aqueous solution of the curing agent is added and stirred uniformly, and the temperature is raised to 50 ° C for 4 hours to prepare a microcapsule dispersion, and the preparation color is prepared. The layer slurry comprises adding a binder and water to the microcapsule dispersion and stirring to form a chromonic layer slurry for use.

In step S320, the undercoat layer is applied onto the substrate by a known coating method such as wire bar, gravure coating, extrusion coating, reverse roll coating or the like and dried.

In step S330, the wet coating of the uneven structure layer is applied on the undercoat layer by a known coating method such as wire bar, gravure coating, extrusion coating, reverse roll coating or the like to obtain a textured structure layer.

In step S340, the coloring layer is applied onto the uneven structure layer by a known coating method such as slope coating or curtain coating, and dried to obtain a coloring film material according to the present disclosure.

4 is a flow chart of a method of preparing a pressure test film in accordance with an embodiment of the present disclosure. As shown in FIG. 4, the preparation method of the pressure test film is basically the same as the preparation method of the chromonic film shown in FIG. 3 except for the steps S410, S450 and S460, and therefore the same part will be referred to the description of FIG. Moreover, the step S410 in the pressure test film preparing method shown in FIG. 4 includes the content in step S310 shown in FIG. However, in accordance with this embodiment of the present disclosure, a slurry for forming a chromogenic film material is prepared in step S410, the paste comprising at least a chromogenic layer slurry, and the chromogenic layer slurry is passed The activated clay is added to water and stirred for pre-dispersion, and then sanded to obtain an aqueous dispersion of activated clay, and added with a binder to uniformly form a coloring layer slurry for use.

Further, in step S450, the coloring layer is applied onto the substrate by a known coating method such as wire bar, gravure coating, extrusion coating, reverse roll coating or the like, and dried to obtain the color developing film material. .

Then, in step S460, the obtained chromonic film material and chromogenic film material are bonded together or temporarily bonded together when they are used to form the pressure test film.

It is to be noted that, in an embodiment according to the present disclosure, the content added in step S410 as shown in FIG. 4 with respect to step S310 shown in FIG. 3, and the content of step S450 shown in FIG. Together, a method for preparing a chromogenic film material can be formed.

Example of a pressure test film according to the present disclosure

The present disclosure will be further described below in conjunction with specific embodiments, but the disclosure is not limited thereto.

(Example 1)

Undercoat slurry preparation

SBR 6kg

PVA217 (10%) 10kg

Water 84kg

6 kg of SBR and 10 kg of 10% aqueous PVA217 solution were added to 84 kg of water, and the mixture was uniformly stirred to prepare an undercoat slurry for use.

Preparation of coating structure for uneven structure layer

20 kg of epoxy acrylate was added to 40 kg of urethane acrylate, and the mixture was uniformly stirred. Then, 25 kg of PET3A and 15 kg of DPHA were added in this order. After stirring uniformly, 3 kg of 184 and 3 kg of TPO were added, and after sufficiently stirring, a slurry of the uneven structure layer was prepared and used.

Production of microcapsules and their dispersions

Preparation of oil phase solution:

3.0 kg of CVL and 2.4 kg of BLMB were added to 60 kg of diisopropylnaphthalene and 5 kg of methyl ethyl ketone, and stirred until completely dissolved, to obtain a dye solution to be used, and 12 kg of a trimethylolpropane adduct of hexamethylene diisocyanate was added to the above dye solution. Stir well and obtain an oil phase solution for use.

Preparation of aqueous solution:

Water 60kg

PVA217 aqueous solution (10%) 40kg

40 kg of 10% aqueous PVA217 solution was added to 60 kg of water, and the mixture was stirred to obtain an aqueous phase solution for use.

Curing agent aqueous solution

Triethylenetetramine 5kg

Water 20kg

Taking the aqueous phase solution as the continuous mobile phase of the membrane emulsifier and the oil phase solution as the dispersed phase, the microcapsule emulsion is obtained by the membrane emulsification method, and then the curing agent aqueous solution is added to the obtained emulsion, and the temperature is raised to 50 ° C under stirring. After continuing to react for 4 hours, it was cooled to room temperature and water was added to adjust the solid content to 30%, thereby obtaining a microcapsule dispersion containing an electron-donating leuco dye precursor.

Preparation of chromonic layer dispersion

20 kg of a 10% aqueous solution of PVA205 and 30 kg of a 10% aqueous solution of CMC were sequentially added to 50 kg of a 30% microcapsule dispersion, and after stirring uniformly, 33 kg of water was added to adjust the solid content to 15% to obtain a chromonic layer dispersion for use.

Preparation of color developing layer dispersion

10 kg of activated clay was added to 30 kg of water, and sand dispersion was used to obtain an aqueous dispersion of activated clay, and 2 kg of SBR and 2 kg of gelatin were added thereto, and the mixture was uniformly stirred to obtain a coloring layer dispersion for use.

On the 75 micron PET substrate, a 0.5 micron undercoat layer and a textured layer were sequentially coated with a wire bar, and a 12 micron chromonic layer was coated with a slope coater, dried, and wound to obtain the pressure of the present disclosure. Test the chromonic film material of the film.

A 13 micron chromogenic layer was coated on a 75 micron PET substrate using a wire bar, and after drying, the chromogenic film material of the pressure test film of the present disclosure was obtained. The resulting chromonic film material was overlaid with the chromogenic film material in a manner opposite to the coating to test its properties.

(Example 2)

Undercoat slurry preparation

SBR 6kg

PVA217 (10%) 10kg

Water 84kg

Preparation of coating structure for uneven structure layer

20 kg of epoxy acrylate was added to 40 kg of urethane acrylate, and the mixture was uniformly stirred. Then, 22 kg of PET3A and 18 kg of DPHA were added in this order. After stirring uniformly, 3 kg of 907 and 3 kg of TPO were added, and the mixture was thoroughly stirred to prepare a slurry of the uneven structure layer for use.

Production of microcapsules and their dispersions

Preparation of oil phase solution:

4.4 kg of CVL and 3.6 kg of BLMB were added to 60 kg of diisopropylnaphthalene and 5 kg of methyl ethyl ketone, stirred until completely dissolved, to obtain a dye solution to be used, and 10 kg of hexamethylene diisocyanate adduct of trihexyl isocyanate was added to the above dye solution. In the middle, stir well to obtain an oil phase solution for use.

Preparation of aqueous solution:

Water 60kg

PVA205 aqueous solution (10%) 40kg

40 kg of 10% aqueous solution of PVA205 was added to 60 kg of water, and the mixture was stirred to obtain an aqueous phase solution for use.

Curing agent aqueous solution

Epoxyethylene butane adduct of ethylenediamine 5kg

Water 20kg

The aqueous phase solution was used as a continuous mobile phase of a membrane emulsifier, and the oil phase solution was used as a dispersed phase to obtain a microcapsule emulsion by a membrane emulsification method. Then, an aqueous solution of a curing agent was added to the obtained emulsion, and the temperature was raised to 50 ° C under stirring, and the reaction was continued for 4 hours, and then cooled to room temperature and water was added to adjust the solid content to 30%, thereby obtaining an electron-donating leuco dye precursor. Microcapsule dispersion.

Preparation of chromonic layer dispersion

Preparation of color developing layer dispersion

10 kg of activated clay was added to 30 kg of water, and dispersed by sanding to obtain an active white clay aqueous dispersion, and then 2 kg of SBR and 2 kg of gelatin were added, and the mixture was uniformly stirred to obtain a coloring layer dispersion for use.

(Example 3)

Undercoat slurry preparation

SBR 5kg

PVA117 (10%) 15kg

Water 80kg

5 kg of SBR and 15 kg of 10% aqueous solution of PVA117 were added to 80 kg of water, and the mixture was uniformly stirred to prepare an undercoat slurry for use.

Preparation of coating structure for uneven structure layer

20 kg of epoxy acrylate was added to 40 kg of urethane acrylate, and the mixture was evenly stirred. Then, 25 kg of TPGDA and 15 kg of DPHA were added in this order. After stirring uniformly, 3 kg of 184 and 3 kg of TPO were added, and the mixture was thoroughly stirred to prepare a slurry of the uneven structure layer for use.

Production of microcapsules and their dispersions

Preparation of oil phase solution:

1.5 kg of CVL and 1.2 kg of BLMB were added to 60 kg of 1-phenyl-1-dimethylphenylethane and 5 kg of methyl ethyl ketone, and stirred until completely dissolved, to obtain a dye solution to be used, and 8 kg of hexamethylene diisocyanate was used. The propane adduct is added to the above dye solution, and stirred well to obtain an oil phase solution for use.

Preparation of aqueous solution:

Water 60kg

PVA217 aqueous solution (10%) 40kg

Curing agent aqueous solution

Hexamethylenediamine 4kg

Water 20kg

Preparation of chromonic layer dispersion

Preparation of color developing layer dispersion

(Example 4)

Undercoat slurry preparation

SBR 5kg

PVA217 (10%) 15kg

Water 80kg

5 kg of SBR and 15 kg of 10% aqueous solution of PVA217 were added to 80 kg of water, and the mixture was uniformly stirred to prepare an undercoat slurry for use.

Preparation of coating structure for uneven structure layer

25 kg of epoxy acrylate was added to 35 kg of urethane acrylate, and the mixture was stirred uniformly. Then, 20 kg of PET3A and 20 kg of PET4A were added in this order. After stirring uniformly, 3 kg of 184 and 3 kg of 907 were added, and the mixture was thoroughly stirred to prepare a slurry of the uneven structure layer for use.

Production of microcapsules and their dispersions

Preparation of oil phase solution:

3.0 kg of CVL and 2.4 kg of BLMB were added to 60 kg of diisopropylnaphthalene and 5 kg of methyl ethyl ketone, stirred until completely dissolved, to obtain a dye solution to be used, and 7.5 kg of a trimethylolpropane adduct of hexamethylene diisocyanate was added to the above dye. In the solution, stir well to obtain an oil phase solution for use.

Preparation of aqueous solution:

Water 60kg

PVA217 aqueous solution (10%) 40kg

Curing agent aqueous solution

Triethylenetetramine 4kg

Water 20kg

Preparation of chromonic layer dispersion

Preparation of color developing layer dispersion

Applying a 0.5 micron undercoat layer to a 75 micron PET substrate in turn, coating the uneven structure layer, coating a 12 micron chromonic layer with a slope coater, drying and winding, and obtaining the present disclosure The chromonic film material of the pressure test film.

(Example 5)

Undercoat slurry preparation

SBR 6kg

PVA117 (10%) 10kg

Water 84kg

6 kg of SBR and 10 kg of 10% aqueous solution of PVA117 were added to 84 kg of water, and the mixture was uniformly stirred to prepare an undercoat slurry for use.

Preparation of coating structure for uneven structure layer

30 kg of epoxy acrylate was added to 30 kg of urethane acrylate, and the mixture was uniformly stirred. Then, 30 kg of DPGDA and 10 kg of PET4A were added in this order. After stirring uniformly, 2.5 kg of 184 and 4 kg of TPO were added, and the mixture was thoroughly stirred to prepare a slurry of the uneven structure layer for use.

Production of microcapsules and their dispersions

Preparation of oil phase solution:

Add 2.0 kg of CVL and 1.6 kg of BLMB to 60 kg of 1-phenyl-1-dimethylphenylethane and 5 kg of methyl ethyl ketone, stir until completely dissolved, to obtain a dye solution to be used, and 12 kg of hexamethylene diisocyanate. The propane adduct is added to the above dye solution, and stirred well to obtain an oil phase solution for use.

Preparation of aqueous solution:

Water 60kg

PVA217 aqueous solution (10%) 40kg

Curing agent aqueous solution

Triethylenetetramine 5kg

Water 20kg

Preparation of chromonic layer dispersion

Preparation of color developing layer dispersion

Comparison with existing pressure test films

(Comparative Example 1)

Undercoat slurry preparation

SBR 6kg

PVA217 (10%) 10kg

Water 84kg

Production of microcapsules and their dispersions

Preparation of oil phase solution:

Add 5.0 kg of CVL and 3.8 kg of BLMB to 60 kg of diisopropylnaphthalene and 5 kg of methyl ethyl ketone, stir until completely dissolved, to obtain a dye solution to be used, and add 12 kg of a trimethylolpropane adduct of hexamethylene diisocyanate to the above dye solution. In the middle, stir well to obtain an oil phase solution for use.

Preparation of aqueous solution:

Water 60kg

PVA217 aqueous solution (10%) 40kg

Curing agent aqueous solution

Triethylenetetramine 5kg

Water 20kg

Using a mechanical emulsification method, an aqueous phase solution was used as a continuous phase, and an oil phase solution was added under high-speed stirring at 750 rpm, and emulsified for 10 minutes to obtain a microcapsule emulsion. Then, an aqueous solution of a curing agent was added to the obtained emulsion, and the temperature was raised to 50 ° C under stirring, and the reaction was continued for 4 hours, and then cooled to room temperature and water was added to adjust the solid content to 30%, thereby obtaining an electron-donating leuco dye precursor. Microcapsule dispersion.

Preparation of chromonic layer dispersion

Preparation of color developing layer dispersion

A 0.5 micron undercoat layer was sequentially coated on a 75 micron PET substrate using a wire bar, and a 12 micron chromonic layer was coated with a slope coater, dried, and wound to obtain a chromonic film material of a pressure test film.

A 13 micron chromogenic layer was coated on a 75 micron PET substrate using a wire bar, and after drying, the chromogenic film material of the pressure test film was obtained. The resulting chromonic film material was overlaid with the chromogenic film material in a manner opposite to the coating to test its properties.

(Comparative Example 2)

Undercoat slurry preparation

SBR 5kg

PVA217 (10%) 15kg

Water 80kg

Preparation of coating structure for uneven structure layer

20 kg of epoxy acrylate was added to 40 kg of urethane acrylate, and the mixture was evenly stirred. Then, 25 kg of PET3A and 15 kg of DPHA were added in this order. After stirring uniformly, 3 kg of 184 and 3 kg of TPO were added, and the mixture was thoroughly stirred to prepare a slurry of the uneven structure layer for use.

Production of microcapsules and their dispersions

Preparation of oil phase solution:

6.5kg CVL and 5.4kg BLMB were added to 60kg of diisopropylnaphthalene and 5kg of methyl ethyl ketone, stirred until completely dissolved, to obtain a dye solution to be used, and 12kg of hexamethylene diisocyanate trimethylolpropane adduct was added to the above dye. In the solution, stir well to obtain an oil phase solution for use.

Preparation of aqueous solution:

Water 60kg

PVA217 aqueous solution (10%) 40kg

Curing agent aqueous solution

Triethylenetetramine 5kg

Water 20kg

Using a mechanical emulsification method, an aqueous phase solution was used as a continuous phase, and an oil phase solution was added under high-speed stirring at 950 rpm, and emulsified for 10 minutes to obtain a microcapsule emulsion. Then, an aqueous solution of a curing agent was added to the obtained emulsion, and the temperature was raised to 50 ° C under stirring, and the reaction was continued for 4 hours, and then cooled to room temperature and water was added to adjust the solid content to 30%, thereby obtaining an electron-donating leuco dye precursor. Microcapsule dispersion.

Preparation of chromonic layer dispersion

On the 75 micron PET substrate, a 0.5 micron undercoat layer and a textured layer were sequentially coated with a wire bar, and a 12 micron chromonic layer was coated with a slope coater, dried, and wound to obtain a pressure test film. Color film material.

Table 1: Performance test data sheets for each example

In the table, the test methods for each performance are as follows:

1. Test method for particle size distribution

The microcapsule dispersion was taken and tested by a BT-9300ST laser particle size distribution analyzer to obtain a particle size distribution D50 and a particle size distribution span of the microcapsule dispersion.

2. A value test method

The sheet coated with the undercoat layer and the uneven structure layer was taken, and the shortest distance between the five adjacent convex portions was measured under an electron microscope (SEM), and an average value was obtained to obtain an A value.

3. Test method for applicability of low temperature color development

The pressure test films obtained above were divided into two groups of I and II, and the following tests were carried out under conditions of 25 ° C and 10 ° C, respectively. First, the above microcapsules were cut into a size of 3 cm×3 cm, and then the color-developing sheet containing the electron-donating leuco dye precursor and the color-developing sheet containing the electron-accepting compound were overlapped in a coating manner and placed. Between the two smooth planes, the entire sheet is subjected to full cover pressure to saturate the color, and then the two sheets that are overlapped are peeled off, and the concentration value of the color developed portion on the color developing sheet is measured by X. rite color difference meter. OD1, the initial concentration value OD0 of the non-color-developing portion of the color-developing sheet was measured by the same method, and the actual color-developing concentration OD was obtained with OD1-OD0. With ODI-ODII, the difference ΔOD between the two groups of sheets at the same pressure at different temperatures can be obtained.

evaluation standard

A (1.5 ≤ OD, ΔOD ≤ 0.2): no dye is precipitated at 10 ° C, and can be used normally;

B (1.3 ≤ OD < 1.5, 0.2 < ΔOD ≤ 0.4): The dye is slightly precipitated at 10 ° C, and does not affect the use;

C (OD<1.3, ΔOD>0.4): The dye was seriously precipitated at 10 ° C and could not be used normally;

4. Test sensitivity test method

The pressure test film obtained above was cut into a size of 20 cm×20 cm, and then the color-developing sheet containing the electron-donating leuco dye precursor and the color-developing sheet containing the electron-accepting compound were overlapped in a coating manner, and It is placed between two smooth planes, and the entire sheet is fully covered and pressed to make it color. Then, the two sheets that are overlapped are peeled off, and 5 sets of different colors are randomly determined on the color developing sheet by X. rite color difference meter. The color density value ODi of the region is obtained, and the average value OD is obtained, and the maximum error value ΔOD is obtained, and the ΔOD is divided by the OD to obtain the percentage value X.

A (X ≤ 5%): the boundary is clearly identifiable and the test sensitivity is high;

B (5% < X ≤ 10%): the boundary definition is acceptable and the test sensitivity is acceptable;

C (10% < X): the boundary is fuzzy and the test sensitivity is poor;

5. Apparent uniformity test method

The pressure test film obtained above was cut into a size of 10 cm×10 cm, and 5 regions were randomly taken, and the appearance of the microcapsules was observed by an electron microscope.

A: The size particles spread evenly, without agglomeration;

B: The size of the particles spreads substantially evenly, without obvious agglomeration;

C: the size of the particles spreads less than uniform, the small particles close to the large particles to form an island structure;

It can be seen from the test results in the table that the low temperature coloring suitability, the test sensitivity and the apparent uniformity are superior to the comparative examples, so the pressure test film prepared by the technical solution of the present disclosure can meet the use requirements of the low temperature environment, and can Achieve high sensitivity, high resolution pressure distribution testing.

The present disclosure is not limited to the embodiments shown in the drawings and described in the specification. The above description is illustrative only and does not limit the scope of the disclosure. Many variations that are within the spirit and scope of the disclosure will be apparent from the description.

Claims

A chromonic film comprising:

a substrate for applying other layers thereon to form a chromonic film;

a textured layer formed on the substrate; and

a coloring layer coated on the uneven structure layer and containing microcapsules containing an electron donating leuco dye precursor, the electron donating leuco dye contacting the electron-accepting compound to be colored,

Wherein when the chromonic film is pressed, the relief structure layer presses the chromonic layer such that the microcapsules in the chromonic layer rupture and are released to the electron leuco dye precursor.
The chromonic film according to claim 1, further comprising an undercoat layer between the substrate and the uneven structure layer for stably supporting the uneven structure layer on the substrate.
The chromonic film according to claim 1 or 2, wherein the uneven structure layer has at least two convex portions, and a linear distance L between the tips of the adjacent two convex portions satisfies the following relationship: D50 × 0.2 ≤ L ≤ D50 × 0.8, where D50 represents the particle diameter corresponding to the cumulative particle size distribution number of the microcapsules reaching 50%.
The chromonic film according to claim 1 or 2, wherein the uneven structure layer is formed of a UV resin.
The chromonic film according to claim 1 or 2, wherein the convex shape on the uneven structure layer is a cylinder, a cone, a rectangular parallelepiped or a square.
The chromonic film according to claim 1 or 2, wherein the top of the convex portion on the uneven structure layer is pointed.
The chromonic film according to claim 2, wherein the undercoat layer is formed by coating with an aqueous resin, preferably a polyvinyl alcohol or a styrene-butadiene copolymer latex-based aqueous resin.
A pressure test film comprising:

a chromonic film layer comprising the chromonic film according to any one of claims 1 to 7;

A color developing film layer containing a color developing material of an electron-accepting compound.
A method of preparing the chromonic film of any of claims 1-7, comprising:

The uneven structure layer slurry is prepared by adding a reactive diluent to the UV resin and stirring uniformly, adding a photoinitiator or an auxiliary agent and stirring uniformly;

By disposing the oil phase and the water phase containing the electron-donating leuco dye precursor, the oil phase is added to the water phase by the membrane emulsification method to form an emulsion, and then the curing agent is uniformly stirred, and the temperature is raised to 50 ° C for 4 hours to form a micro-form. a capsule dispersion, which is further added with a binder and water and stirred to form a chromonic layer slurry;

The uneven structure layer slurry and the coloring layer slurry were sequentially applied onto the substrate to obtain a color developing film usable for the pressure test film.
A method of preparing the pressure test film of claim 8 comprising:

The uneven structure layer slurry is prepared by adding a reactive diluent to the UV resin and stirring uniformly, adding a photoinitiator or an auxiliary agent and stirring uniformly;

By disposing the oil phase and the water phase containing the electron-donating leuco dye precursor, the oil phase is added to the water phase by the membrane emulsification method to form an emulsion, and then the curing agent is uniformly stirred, and the temperature is raised to 50 ° C for 4 hours to form a micro-form. a capsule dispersion, which is further added with a binder and water and stirred to form a chromonic layer slurry;

Pre-dispersion is carried out by adding activated clay to water and stirring, and then sanding to form an active white clay aqueous dispersion by sanding, adding a binder and stirring to form a color developing layer slurry;

The textured structure layer slurry and the chromonic layer slurry are sequentially coated on the substrate to obtain a chromonic film which can be used for the pressure test film, and the chromogenic layer slurry is coated on the substrate to obtain a film which can be used for the pressure test film. Color developing film;

The chromonic film and the chromogenic film are combined into the pressure test film.