JP2014124908A - Discoloration laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a discoloration laminate suitable for an application of discoloration by a liquid except water and an application without discoloration by water, without being influenced by weather and a place for use.SOLUTION: A discoloration laminate 1 is formed of a porous layer 3 fixed to the surface of a support 2 in a state that hydrophobic silica is dispersed in a binder resin and having different transparency in a liquid absorbing state and a non-liquid absorbing state. The porous layer having an interfacial tension value of more than 0 mN/m and less than 60 mN/m does not absorb a liquid having an interfacial tension value of more than 60 mN/m when being contacted with the liquid and absorbs a liquid having an interfacial tension value of less than 60 mN/m when being contacted with the liquid to become transparent.

Description

  The present invention relates to a discolorable laminate. More specifically, the present invention relates to a discolorable laminate that does not change color even when water adheres and changes color when a liquid having a specific interface tension value or less adheres.

Conventionally, a water image sheet provided with a coating layer having different transparency in a water-absorbing state and a non-water-absorbing state in which a low refractive index pigment such as silica is fixed in a binder resin in a dispersed state has been disclosed (for example, see Patent Document 1). ).
The water image sheet becomes transparent when the coating layer absorbs water, becomes opaque in a dry state, and can visually recognize the hue and image of the lower layer, and is disclosed for use in toys and games.
However, since the water image sheet is discolored by water, the water sheet is used for discoloration by using a liquid other than water, or for the purpose of not discoloring by water, for example, when used in a bath or a pool. Even if it adheres, it does not change color and is not suitable for changing the color by using a liquid other than water.

JP-A-63-260476

  The present invention further enhances the applicability of the color-changing laminate that changes color when this kind of liquid is applied, and is intended to be used for changing color with a liquid other than water and not to change color with water. An object of the present invention is to provide a discolorable laminate suitable for use.

In the present invention, a porous layer in which hydrophobic silica is fixed to a binder resin in a dispersed state is provided on the surface of the support, and the transparency is different between the liquid-absorbing state and the non-liquid-absorbing state. A liquid with an interfacial tension value of less than 60 mN / m is not absorbed when a liquid with an interface tension value exceeding 0 mN / m and less than 60 mN / m is brought into contact with the liquid. A requirement is a discolorable laminate that absorbs liquid when brought into contact and becomes transparent.
Furthermore, it is a requirement that the color change (ΔE) before and after liquid absorption is 1 or less.

  INDUSTRIAL APPLICABILITY The present invention can provide a discolorable laminate that is suitable for uses that are not affected by the weather and the place of use and that are discolored with a liquid other than water, or that are intended to be discolored with water.

It is a longitudinal cross-sectional explanatory drawing of one Example of this invention discoloration laminated body.

The discolorable laminate of the present invention is provided with a porous layer having hydrophobicity different from the liquid absorption state and the non-liquid absorption state in which hydrophobic silica is fixed to a binder resin in a dispersed state on the support surface.
The material of the support is not particularly limited, and examples thereof include paper, synthetic paper, knitted fabric, woven fabric, non-woven fabric and the like, synthetic leather, leather, plastic, metal, glass, ceramics, wood, and stone.
The shape of the support is not particularly limited, and may be a shape having irregularities in addition to a planar shape and a sheet shape.
In addition, the colored layer containing a coloring agent can also be provided between the said support body and porous layer.

Next, the hydrophobic silica contained in the porous layer will be described.
Silica is classified into a dry method and a wet method depending on the production method, and both have a structure in which silanol groups are arranged on the surface.
Hydrophobic silica reacts silanol groups with silanes such as methylchlorosilane, siloxanes such as polydimethylsiloxane, hexamethyldisilazane, etc. to change the hydrophilicity of silanol groups to hydrophobic, so it not only absorbs water. Shows water repellency.
As general-purpose hydrophobic silica, trade names Nippil SS-10, SS-20, SS-70, SS-40, SS-50, SS-50, SS-100, Nippon Aerosil Co., Ltd. manufactured by Tosoh Silica Co., Ltd. Product names AEROSIL R972, RY50, R812, R805, RX200, RY200, trade names TS-530, TS-610, TS-720, manufactured by Degussa Japan Co., Ltd. Names AEROSIL R202, R805, R812, trade names REOLOSIL MT-10, DM-10, DM-20S made by Tokuyama Corporation, trade names SYLOPHOBIC100, 200, 704, made by Fuji Silysia Chemical Co., Ltd. 4004, 507, 702, 505, 603, and the like.
The hydrophobic silica has a refractive index in the range of 1.4 to 1.8 and exhibits good transparency when liquid is absorbed.
The particle diameter of the hydrophobic silica is not particularly limited, but 0.03 to 10.0 μm is preferably used.
Two or more hydrophobic silicas can be used in combination.

The hydrophobic silica is dispersed in a solvent containing a binder resin to prepare a liquid material such as paint or printing ink, and printing methods such as screen printing, offset printing, gravure printing, coater, tampo printing, transfer, brush A porous layer is provided on the support surface by a method such as coating, spray coating, electrostatic coating, electrodeposition coating, flow coating, roller coating, or dip coating.
The hydrophobic silica is preferably dispersed in an organic solvent because it is difficult to disperse in an aqueous emulsion as well as water dispersion by ordinary methods.
The binder resin is dissolved or dispersed in an organic solvent, and a liquid material containing hydrophobic silica is applied entirely or partially on a support and dried to obtain a porous layer.
Examples of the organic solvent include n-paraffin solvents, isoparaffin solvents, naphthene solvents, aromatic solvents, α-olefin solvents and other petroleum solvents, light oil, spindle oil, machine oil, cylinder oil, turpentine oil, Examples include mineral spirit, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, ethyl acetate, propyl acetate, butyl acetate, ethyl lactate, xylene, toluene, ethanol, isopropyl alcohol, butanol and the like.
Examples of the binder resin include urethane resin, nylon resin, vinyl acetate resin, acrylic ester resin, acrylic ester copolymer resin, acrylic polyol resin, vinyl chloride-vinyl acetate copolymer resin, maleic resin, polyester resin, styrene. Resin, styrene copolymer resin, polyethylene resin, polycarbonate resin, epoxy resin, styrene-butadiene copolymer resin, acrylonitrile-butadiene copolymer resin, methyl methacrylate-butadiene copolymer resin, butadiene resin, chloroprene resin, melamine resin, and the above Each resin emulsion, casein, starch, cellulose derivative, polyvinyl alcohol, urea resin, phenol resin and the like can be mentioned.
The binder resin soluble in the organic solvent includes acrylic resin, urethane resin, polyester resin, alkyd resin, epoxy resin, melamine resin, styrene resin, nylon resin, vinyl acetate resin. , Vinyl chloride resin, vinyl chloride-vinyl acetate copolymer resin, high impact polystyrene, acrylonitrile-butadiene-styrene copolymer resin, cellulose resin and the like.
The mixing ratio of the hydrophobic silica and the binder resin depends on the type and properties of the hydrophobic silica, but is preferably 0.5 to 2 parts by mass of the binder resin solid content with respect to 1 part by mass of the hydrophobic silica. More preferably, it is 0.8 to 1.5 parts by mass. When the binder resin solid content is less than 0.5 parts by mass with respect to 1 part by mass of the hydrophobic silica, it is difficult to obtain a practical film strength of the porous layer to be formed, and it exceeds 2 parts by mass. In this case, the permeability of the liquid into the hydrophobic silica tends to be impaired.
Since the porous layer has a smaller mixing ratio of the binder resin to the colorant than a general coating film, it is difficult to obtain sufficient film strength. Therefore, among the binder resins, it is preferable to increase the scratch resistance using a nylon resin, a urethane resin, or an acrylic resin.
Examples of the urethane resin include a polyester urethane resin, a polycarbonate urethane resin, and a polyether urethane resin, and two or more of them can be used in combination.
The urethane resin can be used alone, but other binder resins can be used in combination depending on the type of support and the performance required for the coating.
In the binder resin, the crosslinkable resin can be further improved in film strength by adding an arbitrary crosslinking agent and crosslinking.
The binder resin has a large or small affinity with the liquid. By combining these, the permeation time into the porous layer, the degree of permeation, and the slow speed of drying after permeation can be adjusted. Furthermore, the said adjustment can be controlled by adding a dispersing agent suitably.
A colorant may be contained in the porous layer.

Alternatively, a porous layer can be provided by applying a resin composition in which hydrophobic silica is mixed in a resin to the support surface.
Examples of the resin include thermoplastic resins, thermosetting resins, radiation curable resins, and two-component curable resins.
Specifically, after applying a resin composition in which hydrophobic silica is mixed and dispersed in a heat-melted resin to a support, it is cooled to form a porous layer or cured with radiation such as ultraviolet rays. A resin composition in which hydrophobic silica is mixed and dispersed on a support, and then irradiated with light to form a porous layer, or a resin that is mixed and dispersed in a resin that is cured by mixing a curing agent. After the composition is applied to the support, it is cured to form a porous layer, or a resin composition in which hydrophobic silica is mixed and dispersed in a resin that is solidified from a sol to a gel is applied to the support. After the process, the porous layer can be formed by changing to a gel state by heat or the like.
Examples of the resin include high density polyethylene, medium low density polyethylene, linear low density polyethylene, polypropylene, ethylene-methacrylic acid copolymer resin (ionomer resin), ethylene-vinyl acetate-vinyl chloride graft copolymer resin, chlorinated polyethylene, chlorine Polypropylene, ethylene-α-olefin copolymer resin, ethylene-propylene copolymer resin, methylpentene polymer, ethylene-propylene-diethylene elastomer-acrylonitrile copolymer resin, vinyl chloride-propylene copolymer resin, butadiene resin, polystyrene, high impact Polystyrene, acrylonitrile-acrylic-styrene copolymer resin, acrylonitrile-styrene copolymer resin, acrylonitrile-butadiene-styrene copolymer resin, vinyl chloride resin, salt Vinylidene resin, polyvinyl acetate, vinyl chloride-vinylidene chloride copolymer resin, polyacetal, polyamide, polycarbonate, polyethylene terephthalate, low softening point polyester, copolymer nylon, polyacrylate, polymethyl methacrylate resin, low molecular weight polyethylene, low molecular weight Examples include polypropylene, styrene-butadiene block copolymer resin, and styrene-ethylene-butadiene block copolymer resin. Various additives such as a plasticizer, a nucleating agent, and a release agent can be added to these resins.
Examples of the radiation curable resin include silicon resin, unsaturated polyester, epoxy resin, polyurethane, melamine resin, and polyurea.

The porous layer of the discolorable laminate has an interfacial tension value of more than 0 mN / m and less than 60 mN / m.
Therefore, the porous layer does not absorb liquid when contacted with liquid exceeding the interfacial tension value, and the discolorable laminate does not change color.
Further, when a liquid having an interface tension value less than that of the porous layer is brought into contact with the liquid, the liquid is absorbed to make the porous layer transparent, and the color of the lower layer is visually recognized.
As an example, even if water (interfacial tension value 72 mN / m) is adhered, the porous layer does not absorb water and repels water on the surface, so the porous layer does not become transparent and discoloration does not occur.
On the other hand, when ethanol (interfacial tension value 22 mN / m) or olive oil (interfacial tension value 35 mN / m) is attached as an organic solvent, the porous layer absorbs the organic solvent and becomes transparent, and the color of the lower layer is visually recognized. It becomes like this.
When the organic solvent contained in the porous layer evaporates, the porous layer becomes opaque and returns to its original state.
Furthermore, when a liquid composition obtained by adding a surfactant to the water (for example, an interfacial tension value of 24 N / m) is adhered, the porous layer absorbs the liquid composition and becomes transparent, and the color of the lower layer is visually recognized. Become so.
When the water contained in the porous layer evaporates, the porous layer becomes opaque and returns to its original state. However, the surfactant is present in the porous layer. Since the porous layer in the place where the water is present becomes transparent and the porous layer in the place where the surfactant does not exist repels water, only the place where the initial liquid composition is adhered can be discolored.
This state returns to the original state by washing the discolorable laminate with excess water to remove the surfactant in the porous layer.
In the discolorable laminate, the color change (ΔE) before and after liquid absorption of the porous layer is preferably 1 or more, more preferably 5 or more.
When the color change (ΔE) before and after liquid absorption of the porous layer is 1 or more, the color change becomes clear, and when ΔE is less than 1, the color change is difficult to distinguish.

Specific embodiments of the color-changing laminate of the present invention include, for example, dolls, doll costumes such as raincoats, doll accessories such as umbrellas and helmets, water gun targets, models imitating cars and ships, Boards and toys that show traces of human and doll's handprints and footprints, writing materials such as writing sheets, clothes such as dresses, raincoats, shoes such as rain boots, printed materials such as books and calendars, stamp cards And entertainment tools such as puzzles and various games, kitchen tools such as coasters and cups, artificial flowers, and winning lotteries.
Also, it can be applied as various indicators, for example, detection of liquid leaks in pipes, tanks, etc., detection of liquid wetting in chemical transportation and storage locations, and the like.

  The color-changing laminate may be combined with a liquid composition for a color-changing laminate to form a color-changing laminate set, or the color-changing laminate, the liquid composition for a color-changing laminate, and the liquid composition. Combining containers containing objects to form a discolorable laminate set, or applying a discolorable laminate and the liquid composition, and a plastic porous body or fiber processed body having continuous pores as a nib member A discolorable laminate set can also be configured by combining a writing instrument or an applicator in the form of an applicator.

As an attachment tool in the form of a writing instrument or applicator applied to a plastic porous body or fiber processed body having continuous pores as a nib member, an adhering tool having a nib member at the tip, a liquid composition is contained in the container, In addition, examples include a fibrous body for drawing out the liquid composition in the container, an attachment provided with a brush, and the like.
The plastic porous body or fiber processed body having continuous pores may be any material that absorbs and discharges a liquid composition in an appropriate amount, such as general-purpose polyolefin-based, polyurethane-based, and other various plastic continuous pores and fibers. Examples include a focused brush-like one, a fiber processed by resin processing or heat welding, a felt, and a non-woven fabric, and the shape and dimensions can be arbitrarily set.

Examples will be described below, but the present invention is not limited to these examples.
In addition, the part in an Example is a mass part.
Measuring method of interfacial tension value The interfacial tension value of the solid surface was measured according to the JIS K6768 wet tension test method. The interfacial tension value of the liquid was measured at 20 ° C. with an automatic surface tension meter (CBVP-A3) manufactured by Kyowa Interface Science Co., Ltd.
Method for Measuring Color Change Value (ΔE) A ΔE value (Lab value) after change was measured by using Spectro Eye manufactured by Gretag Macbeth and using the color before change as a standard.
Method for Measuring Refractive Index of Hydrophobic Silica Using a contact liquid (refractive liquid) manufactured by Shimadzu Corporation, the refractive index of hydrophobic silica was measured by a liquid immersion method (Becke line method).

Example 1 (see FIG. 1)
10 parts of hydrophobic silica (manufactured by Tosoh Silica Co., Ltd., product name: NipSeal SS20), 10 parts of vinyl chloride-vinyl acetate copolymer resin (manufactured by Nissin Chemical Industry Co., Ltd., product name: Solvain A), 25 parts of cyclohexanone, Printing ink was obtained by mixing 1 part of a nonionic additive.
Using the printing ink, printing was performed on a blue cast coated paper having a thickness of 100 μm as a support 2 by screen printing and dried to provide a porous layer 3 to obtain a discolorable laminate 1.
The interfacial tension value on the surface of the porous layer of the discolorable laminate was 50 mN / m, and ΔE before and after the change was 30.55.
Even when water having an interfacial tension of 72 mN / m was adhered to the surface, the color-change laminate had a white state without being discolored to repel water. Next, when ethyl alcohol having an interfacial tension value of 22 mN / m was adhered to the surface, the porous layer at that portion became liquid-absorbed and transparent, and the blue color due to the underlying support was visible.
When the ethyl alcohol in the porous layer was evaporated and dried, the porous layer became original white again.

Example 2
Hydrophobic silica (manufactured by Tosoh Silica Co., Ltd., product name: NipSeal SS70) 13 parts, vinyl chloride-vinyl acetate copolymer resin (manufactured by Nissin Chemical Industry Co., Ltd., product name: Solvain A) 10 parts, cyclohexanone 20 parts, A printing ink was obtained by mixing 8 parts of a high-boiling hydrocarbon solvent (Solvesso 150) and 1 part of a nonionic additive.
Using the printing ink, a porous layer was provided by printing and drying on a transparent polyethylene terephthalate film having a thickness of 100 μm as a support to obtain a discolorable laminate.
The interfacial tension value of the porous layer surface of the discolorable laminate is 48 mN / m, and ΔE before and after the change is 2.20 when white paper is placed on the base, and 27. 42.
Even when water having an interfacial tension value of 72 mN / m was adhered, the color-change laminate had a white state without being discolored to repel water. Next, when a 30% aqueous solution of ethyl alcohol having an interfacial tension value of 33 mN / m was adhered to the surface, the porous layer at that portion absorbed the liquid and became transparent.
When the 30% aqueous ethyl alcohol solution in the porous layer was evaporated and dried, the porous layer became white again.

Example 3
8 parts of hydrophobic silica (manufactured by Fuji Silysia Chemical Co., Ltd., product name: silo hovic 200), 10 parts of vinyl chloride-vinyl acetate copolymer resin (manufactured by Nissin Chemical Industry Co., Ltd., product name: sorbine C), 40 methyl ethyl ketone Part and 20 parts of xylene were mixed to obtain a spray ink.
Using the spray ink, spray coating was performed on a red soft vinyl chloride molded article as a support, followed by drying to provide a porous layer to obtain a discolorable laminate.
The interfacial tension value on the surface of the porous layer of the discolorable laminate was 58 mN / m, and ΔE before and after the change was 48.22.
Even when water having an interfacial tension value of 72 mN / m was adhered, the color-change laminate had a white state without being discolored to repel water. Subsequently, when a 30% surfactant aqueous solution having an interfacial tension value of 25 mN / m was attached to the surface, the porous layer at that portion became liquid-absorbed and transparent, and the red color due to the underlying support was visible.
When the medium in the 30% surfactant aqueous solution in the porous layer is dried, it becomes the original white color again. When water with an interfacial tension of 72 mN / m is attached to the discolorable laminate in this state, the portion changes from white to red. The discoloration behavior was different from the initial one.
When the water in the porous layer is dried, it becomes the original white color again, and the interfacial tension value is 72 mN by washing the discolorable laminate with running water to remove the surfactant remaining in the porous layer and drying it. The porous layer did not change color even when / m of water was attached, and it returned to its original state, and this change could be repeated.

Example 4
12 parts of hydrophobic silica (manufactured by Fuji Silysia Chemical Co., Ltd., product name: silo hovic 200), 20 parts of acrylic resin 50% toluene / butyl acetate solution (manufactured by DIC Corporation, product name: Acrydic A-817), methyl ethyl ketone 15 parts and 15 parts of xylene were mixed to obtain a spray ink.
Using the spray ink, spray coating was performed on a green ABS resin molding as a support, followed by drying to provide a porous layer to obtain a discolorable laminate.
The interfacial tension value on the surface of the porous layer of the discolorable laminate was 56 mN / m, and ΔE before and after the change was 17.54.
Even when water having an interfacial tension value of 72 mN / m was adhered, the color-change laminate had a white state without being discolored to repel water. Next, when a 30% surfactant aqueous solution having an interfacial tension value of 25 mN / m was attached to the surface, the porous layer at that portion became liquid-absorbed and transparent, and the green color due to the underlying support was visible.
When the medium in the 30% surfactant aqueous solution in the porous layer is dried, it becomes the original white color again. When water with an interfacial tension of 72 mN / m is adhered to this state, the portion changes from white to green. The discoloration behavior was different from the initial one.
When the water in the porous layer is dried, it becomes the original white color again, and the interfacial tension value is 72 mN by washing the discolorable laminate with running water to remove the surfactant remaining in the porous layer and drying it. The porous layer did not change color even when / m of water was attached, and it returned to its original state, and this change could be repeated.

Example 5
Hydrophobic silica (manufactured by Tosoh Silica Co., Ltd., product name: Nipseal SS70) 13 parts, fluorescent pink pigment 0.5 part, vinyl chloride-vinyl acetate copolymer resin (manufactured by Nissin Chemical Industry Co., Ltd., product name: Solvein A) ) 10 parts, 20 parts of cyclohexanone, 8 parts of a high boiling point hydrocarbon solvent (Sorvesso 150) and 1 part of a nonionic additive were mixed to obtain a printing ink.
Using the printing ink, a porous layer was provided by printing and drying on a blue polyethylene terephthalate film having a thickness of 100 μm as a support to obtain a discolorable laminate.
The interfacial tension value on the porous layer surface of the discolorable laminate was 48 mN / m, and ΔE before and after the change was 48.82.
Even when water having an interfacial tension value of 72 mN / m was adhered, the discolorable laminate had a light pink state without being discolored to repel water. Next, when a 50% aqueous solution of ethyl alcohol having an interfacial tension value of 28 mN / m is attached to the surface, the porous layer in the portion absorbs the liquid and becomes transparent, and a purple color mixed with the blue color of the underlying support is visible. It was done.
When the 50% ethyl alcohol aqueous solution in the porous layer was evaporated and dried, the porous layer became the original light pink again.

DESCRIPTION OF SYMBOLS 1 Color change laminated body 2 Support body 3 Porous layer

Claims (2)

  On the surface of the support, a porous layer in which hydrophobic silica is fixed in a dispersed state in a binder resin is provided with a porous layer having different transparency in a liquid-absorbing state and a non-liquid-absorbing state. The porous layer has an interfacial tension value of 0 mN When liquid with an interfacial tension value of more than 60 mN / m is contacted with a liquid with an interfacial tension value of less than 60 mN / m Color-changing laminate that absorbs liquid and becomes transparent.   The color-change laminate according to claim 1, wherein the color change (ΔE) before and after liquid absorption is 1 or less.

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