INTERMEDIATE FILM FOR LAMINATED GLASS HAVING THERMOCHROMIC PROPERTIES, LAMINATED GLASS, AND LAMINATED GLASS SYSTEM

Abstract

The present invention aims to provide a thermochromic interlayer film for a laminated glass capable of uniformly changing its color, a laminated glass produced using the thermochromic interlayer film for a laminated glass, and a laminated glass system including the laminated glass. Provided is a thermochromic interlayer film for a laminated glass including: a pyrogenic layer; and a thermochromic layer that contains a thermoplastic resin and a thermochromic substance, stacked on at least one surface of the pyrogenic layer.

Claims

1. A thermochromic interlayer film for a laminated glass comprising: a pyrogenic layer; and a thermochromic layer that contains a thermoplastic resin and a thermochromic substance, stacked on at least one surface of the pyrogenic layer.

2. The thermochromic interlayer film for a laminated glass according to claim 1, wherein the pyrogenic layer has a surface resistivity of 10/ or lower.

3. The thermochromic interlayer film for a laminated glass according to claim 1, wherein the thermochromic substance is a dye or a pigment that repeats color development and fade by heating and cooling.

4. The thermochromic interlayer film for a laminated glass according to claim 1, wherein the thermochromic substance is a dye or a pigment that starts changing its color by heating at a temperature of 20 C. to 70 C.

5. The thermochromic interlayer film for a laminated glass according to claim 1, wherein the thermoplastic resin is a polyvinyl acetal.

6. A laminated glass comprising: the interlayer film for a laminated glass according to claim 1; and a pair of glass plates sandwiching the interlayer film for a laminated glass.

7. A laminated glass system comprising: the laminated glass according to claim 6; and a voltage supply part for applying a voltage to the pyrogenic layer in the thermochromic interlayer film for a laminated glass in the laminated glass.

8. A laminated glass comprising: a pyrogenic layer; an interlayer film for a laminated glass comprising a thermochromic layer that contains a thermoplastic resin and a thermochromic substance; and a pair of glass plates sandwiching the pyrogenic layer and the interlayer film for a laminated glass.

9. The laminated glass according to claim 8, wherein the interlayer film for a laminated glass is stacked at least on one surface of the pyrogenic layer.

10. The laminated glass according to claim 9, wherein one of the glass plates is stacked on the other surface of the pyrogenic layer opposite to the surface on which the interlayer film for a laminated glass is stacked.

11. A laminated glass system comprising: the laminated glass according to claim 8; and a voltage supply part for applying a voltage to the pyrogenic layer in the laminated glass.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0099] FIG. 1 is a schematic view illustrating an exemplary cross section in the thickness direction of the interlayer film for a laminated glass of the present invention.

DESCRIPTION OF EMBODIMENTS

[0100] Embodiments of the present invention are more specifically described with reference to, but not limited to, the following examples.

Example 1

[0101] (1) Preparation of Pyrogenic Layer and the Like

[0102] The substrate used was a polyethylene terephthalate (PET) film with a thickness of 50 m.

[0103] Sputtering was performed on the substrate using titanium as a target. The sputtering was performed under the conditions of a sputtering power of 1,500 W at medium frequencies (MF), an atmospheric gas of argon gas at a gas flow rate of 225 sccm and oxygen gas at a gas flow rate of 58 sccm, and a sputtering pressure of 0.177 Pa. Thus, a metal oxide layer formed of titanium oxide (TiO.sub.2) with a thickness of 30 nm was formed.

[0104] Next, sputtering was performed on the metal oxide layer using titanium as a target. The sputtering was performed under the conditions of a sputtering power of 1,500 W at medium frequencies (MF), an atmospheric gas of argon gas at a gas flow rate of 225 sccm and oxygen gas at a gas flow rate of 26 sccm, and a sputtering pressure of 0.170 Pa. Thus, an oxygen-deficient metal oxide layer formed of an oxygen-deficient titanium oxide (TiO.sub.x wherein x is less than 2) with a thickness of 4 nm was formed.

[0105] Subsequently, sputtering was performed on the oxygen-deficient metal oxide layer using silver as a target. The sputtering was performed under the conditions of a sputtering power of 1,150 W of direct current (DC), an atmospheric gas of argon at a gas flow rate of 225 sccm, and a sputtering pressure of 0.28 Pa. Thus, a silver layer formed of silver with a thickness of 16 nm was formed.

[0106] A conductive layer was formed under the same sputtering conditions for the metal oxide layer, the oxygen-deficient metal oxide layer, and the silver layer as above, except that the thickness of each layer formed by sputtering was changed. Specifically, a conductive layer formed included, on a substrate, a metal oxide layer (30 nm)/an oxygen-deficient metal oxide layer (4 nm)/a silver layer (16 nm)/an oxygen-deficient metal oxide layer (4 nm)/a metal oxide layer (80 nm)/an oxygen-deficient metal oxide layer (4 nm)/a silver layer (16 nm)/an oxygen-deficient metal oxide layer (4 nm)/a metal oxide layer (30 nm) in this order.

[0107] The obtained conductive layer had a surface resistivity of 1.5 /.

[0108] (2) Preparation of Thermochromic Layer 1

[0109] To 100 parts by weight of polyvinyl butyral were added 0.5 parts by weight of an orange thermochromic ink, 40 parts by weight of a plasticizer, 0.5 parts by weight of a UV blocking agent, and 0.5 parts by weight of an antioxidant. They were sufficiently kneaded using a mixing roll to prepare a composition.

[0110] The polyvinyl butyral used had a hydroxy group content of 30 mol %, a degree of acetylation of 1 mol %, a degree of butyralization of 69 mol %, and an average degree of polymerization of 1,700. The thermochromic ink used was an orange thermochromic ink extracted from a FRIXION light highlighter (SFL-10SL-0 available from Pilot. Corporation), The plasticizer used was triethylene glycol di-2-ethylhexanoate (3GO). The UV blocking agent used was 2-(2-hydroxy-3-t-butyl-5-methylphenyl)-5-chlorobenzotriazole (Tinuvin326 available from BASF SE). The antioxidant used was 2,6-di-t-butyl-p-cresol (BHT).

[0111] The obtained composition was extruded from an extruder to provide a single-layer thermochromic layer 1 with a thickness of 380 m.

[0112] The obtained thermochromic layer 1 was orange at room temperature (25 C.)

[0113] (3) Production of interlayer film for laminated glass and laminated glass

[0114] A substrate having a conductive layer formed thereon was sandwiched between two sheets of the obtained thermochromic layers 1, and the laminate was thermally pressure-bonded. Thus, an interlayer film for a laminated glass having a laminated structure (a thermochromic layer 1/a conductive layer/a substrate/a thermochromic layer 1) was produced. The thermal pressure-bonding was performed by the roll-to-roll process using a thermal pressure bonding laminator (MRK-650Y type available from MCK Co., Ltd.) under the conditions of a heating temperature of 75 C., a pressure for the pressure bonding of 1.0 kN, and a tension during conveyance of 20 N. The upper and lower lamination rolls used for the thermal pressure bonding were both made of rubber.

[0115] Two transparent clear glass plates (1,000 mm in length300 mm in width1.8 mm in thickness) were prepared. To one of the two transparent clear glass plates were attached one-sided copper foil tapes (STS-CU42S available from Sekisui Techno Trading West Japan Co., Ltd.) on both 1000-mm sides as electrodes. The copper foil tapes were attached in a manner as to partly protrude from the glass plate for connection to a power source. Next, the interlayer film for a laminated glass was cut to a size of 1,000 mm in length300 mm in width. Edges having a width of about 15 mm on both 1,000-mm sides of the thermochromic layer 1 on the conductive layer side were cut off so that the copper foil tapes attached to the glass and the surface of the conductive layer on the side opposite to the substrate side were in contact with each other during the production of a laminated glass.

[0116] The resulting interlayer film for a laminated glass was stacked to provide a laminate including a clear glass plate with copper foil tapes attached thereto/a thermochromic layer 1/a conductive layer/a substrate/a thermochromic layer 1/a clear glass plate with no copper foil tape attached thereto stacked in this order. The obtained laminate was preliminarily pressure-bonded using heating rolls at 230 C. Then, the preliminarily pressure bonded laminate was further pressure-bonded by the heating roll method using an autoclave under the conditions of 1.35 C. and a pressure of 1.2 MPa for 20 minutes. Thus, a laminated glass was produced.

Example 2

[0117] (1) Preparation of Thermochromic Layer 2

[0118] To 100 parts by weight of polyvinyl butyral were added 0.5 parts by weight of a blue thermochromic ink, 40 parts by weight of a plasticizer, 0.5 parts by weight of UV blocking agent, and 0.5 parts by weight of an antioxidant. They were sufficiently kneaded using a mixing roll to prepare a composition.

[0119] The polyvinyl butyral used had a hydroxy group content of 30 mol %, a degree of acetylation of 1 mol %, a degree of butyralization of 69 mol %, and an average degree of polymerization of 1,700. The thermochromic ink used was blue-black (hereafter, also abbreviated as BB) thermochromic ink extracted from a FRIXION BALL KNOCK ballpoint pen (LFBK-23EF-BB available from Pilot Corporation). The plasticizer used was triethylene glycol di-2-ethylhexanoate (3GO). The UV blocking agent used was 2-(2-hydroxy-3-t-butyl-5-methylphenyl)-5-chlorobenzotriazole (Tinuvin326 available from BASF SE). The antioxidant used was 2,6-di--t-butyl-p-cresol (BHT).

[0120] The obtained composition was extruded from an extruder to provide a single-layer thermochromic layer 2 with a thickness of 380 m.

[0121] The obtained thermochromic layer 2 was blue at room temperature (25 C.).

[0122] (2) Preparation of Protective Layer 3

[0123] To 100 parts by weight of polyvinyl butyral were added 40 parts by weight of a plasticizer, 0.5 parts by weight of a UV blocking agent, and 0.5 parts by weight of an antioxidant, They were sufficiently kneaded using a mixing roll to prepare a composition.

[0124] The polyvinyl butyral used had a hydroxy group content of 30 mol %, a degree of acetylation of 1 mol %, a degree of butyralization of 69 mol %, and an average degree of polymerization of 1,700. The plasticizer used was triethylene glycol di-2-ethylhexanoate (3GO). The UV blocking agent used was 2-(2f-hydroxy-3-t-butyl-5-methylphenyl)-5-chlorobenzotriazole (Tinuvin326 available from BASF SE). The antioxidant used was 2,6-di-t-butyl-p-cresol (BHT).

[0125] The obtained composition was extruded from an extruder to provide a single-layer protective layer 3 with a thickness of 380 m.

[0126] (3) Production of Interlayer Film for Laminated Glass and Laminated Glass

[0127] A substrate having a conductive layer formed thereon as in Example 1 was sandwiched between the obtained thermochromic layer 2 and the protective layer 3, and the laminate was thermally pressure-bonded. Thus, an interlayer film for a laminated glass having a laminated structure (a thermochromic layer 2/a conductive layer/a substrate/a protective layer 3) was produced. The thermal pressure-bonding was performed by the roll-to-roll process using a thermal pressure bonding laminator (MRK-650Y type available from MCK Co., Ltd.) under the conditions of heating temperature of 75 C., a pressure for the pressure bonding of 1.0 kN, and a tension during conveyance of 20 N, The upper and lower lamination rolls used for the thermal pressure bonding were both made of rubber, A laminated glass was produced as in Example 1, except that both sides of the thermochromic layer 2, instead of the thermochromic Layer 1 on the conductive layer side in Example 1, were cut off.

Example 3

[0128] (1) Preparation of Thermochromic Layer 4

[0129] To 100 parts by weight of polyvinyl butyral were added 0.5 parts by weight of a green thermochromic ink, 40 parts by weight of a plasticizer, 0.5 parts by weight of UV blocking agent, and 0.5 parts by weight of an antioxidant, They were sufficiently kneaded using a mixing roll to prepare a composition.

[0130] The polyvinyl butyral used had a hydroxy group content of 30 mol %, a degree of acetylation of 1 mol %, a degree of butyralization of 69 mol %, and an average degree of polymerization of 1,700. The thermochromic ink used was a green thermochromic ink extracted from a FRIXION BALL KNOCK ballpoint pen (LFBK-23EF-BB available from Pilot Corporation). The plasticizer used was triethylene glycol di-2-ethylhexanoate (3GO). The UV blocking agent used was 2-(2-hydroxy-3-t-butyl-5-methylphenyl)-5-chlorobenzotriazole (Tinuvin326 available from BASF SE). The antioxidant used was 2,6-di-t-butyl-p-cresol (BHT).

[0131] The obtained composition was extruded from an extruder to provide a single-layer thermochromic layer 4 with a thickness of 380 m.

[0132] The obtained thermochromic layer 4 was green at room temperature (25 C.).

[0133] (2) Production of Interlayer Film for Laminated Glass and Laminated Glass

[0134] A substrate having a conductive layer formed thereon as in Example 1 was sandwiched between the protective layer 3 obtained as in Example 2 and the obtained thermochromic layer 4, and the laminate was thermally pressure-bonded, Thus, an interlayer film for a laminated glass having a laminated structure (a protective layer 3/a conductive layer/a substrate/a thermochromic layer 4) was produced. The thermal pressure-bonding was performed by the roll-to-roll process using a thermal pressure bonding laminator (MRK-650Y type available from MCI Co., Ltd.) under the conditions of a heating temperature of 75 C., a pressure for the pressure bonding of 1.0 kN, and a tension during conveyance of 20 N, The upper and lower lamination rolls used for the thermal pressure bonding were both made of rubber.

[0135] A laminated, glass was produced as in Example 1, except that both sides of the protective layer 3, instead of the thermochromic layer 1 on the conductive layer side in Example 1, were cut off,

Example 4

[0136] (1) Preparation of Thermochromic Layer 5

[0137] To 100 parts by weight of polyvinyl butyral were added 0.5 parts by weight of a yellow thermochromic ink, 40 parts by weight of a plasticizer, 0.5 parts by weight of a UV blocking agent, and 0.5 parts by weight of an antioxidant, They were sufficiently kneaded using a mixing roll to prepare a composition.

[0138] The polyvinyl butyral used had a hydroxy group content of 30 mol %, a degree of acetylation of 1 mol %, a degree of butyralization of 69 mol %, and an average degree of polymerization of 1,700. The thermochromic ink used was a yellow thermochromic ink extracted from a FRIXION light highlighter (SFL-10SL-Y available from Pilot Corporation). The plasticizer used was triethylene glycol di-2-ethylhexanoate (3GO). The WI blocking agent used was 2-(2-hydroxy-3-t-butyl-5-methylphenyl)-5-chlorobenzotriazole (Tinuvin326 available from BASF SE), The antioxidant used was 2,6-di-t-butyl-p-cresol (BHT). The obtained composition was extruded from an extruder to provide a single-layer thermochromic layer 5 with a thickness of 380 m.

[0139] The obtained thermochromic layer 5 was yellow at room temperature (25 C.)

[0140] (2) Production of Interlayer Film for Laminated Glass and Laminated Glass

[0141] A substrate having a conductive layer formed thereon was sandwiched between two sheets of the obtained thermochromic layers 5, and the laminate was thermally pressure-bonded. Thus, an interlayer film for a laminated glass having a laminated structure (a thermochromic layer 5/a conductive layer/a substrate/a thermochromic layer 5) was produced. The thermal pressure-bonding was performed by the roll-to-roll process using a thermal pressure bonding laminator (MRK-650Y type available from MCK Co., Ltd.) under the conditions of a heating temperature of 75 C., a pressure for the pressure bonding of 1.0 kN, and a tension during conveyance of 20 N. The upper and lower lamination rolls used for the thermal pressure bonding were both made of rubber.

[0142] A laminated glass was produced as in Example 1, except that both sides of the thermochromic layer 5 on the conductive layer side, instead of the thermochromic layer 1 on the conductive layer side, were cut off.

Example 5

[0143] (1) Preparation of Pyrogenic Layer or the Like

[0144] A substrate used was a polyethylene terephthalate (PET) film with a thickness of 50 m. Sputtering was performed on the substrate using copper as a target to form a copper layer with a thickness of 2 m. Etching treatment was performed on the formed copper layer, thereby forming a conductive layer patterned with copper lines (width: 10 m) at intervals of 2.5 mm in a grid shape.

[0145] (2) Production of Interlayer Film for Laminated Glass and Laminated Glass

[0146] A substrate having a conductive layer formed thereon was sandwiched between two sheets of thermochromic layers 1 prepared as in Example 1, and the laminate was thermally pressure-bonded. Thus, an interlayer film for a laminated glass having a laminated structure (a thermochromic layer 1/a conductive layer/a substrate/a thermochromic layer 1) was produced. The thermal pressure-bonding was performed by the roll-to-roll process using a thermal pressure bonding laminator (MRK-650Y type available from MCK Co, Ltd.) under the conditions of a heating temperature of 75 C., a pressure for the pressure bonding of 1.0 kN, and a tension during conveyance of 20 N, The upper and lower lamination rolls used for the thermal pressure bonding were both made of rubber.

[0147] Two transparent clear glass plates (1,000 mm in length300 mm in width1.8 mm in thickness) were prepared, To one of the two transparent clear glass plates were attached one-sided copper foil tapes (STS-CU42S available from Sekisui Techno Trading West Japan Co., Ltd.) on both 1000-mm sides as electrodes. The copper foil tapes were attached in a manner as to partly protrude from the glass plate for connection to a power source. Next, the interlayer film for a laminated glass was cut to a size of 1,000 mm in length300 mm in width. Edges having a width of about 15 mm on both 1,000-mm sides of the thermochromic layer 1 on the conductive layer side were cut off so that the copper foil tapes attached to the glass and the surface of the conductive layer on the side opposite to the substrate side were in contact with each other during the production of a laminated glass.

[0148] The resulting interlayer film for a laminated glass was stacked to provide a laminate including a clear glass plate with copper foil tapes attached thereto/a thermochromic layer 1/a conductive layer/a substrate/a thermochromic layer 1/a clear glass plate with no copper foil tape attached thereto stacked in this order. The obtained laminate was preliminarily pressure-bonded using heating rolls at 230 C. Then, the preliminarily pressure-bonded laminate was further pressure-bonded by the heating roll method using an autoclave under the conditions of 135 C. and a pressure of 1.2 MPa for 20 minutes. Thus, a laminated glass was produced.

Example 6

[0149] (1) Preparation of Pyrogenic Layer

[0150] One thermochromic layer 1 was prepared as in Example 1, and cut to a size of 1,000 mm in length300 mm in width. Thus, an interlayer film for a laminated glass was obtained. To the entire surface of the interlayer film for a laminated glass were thermally pressure-bonded tungsten wires (width: 30 m, thickness: 30 m) in parallel to each other at intervals of 2.5 mm as a conductive layer.

[0151] (2) Production of an Interlayer Film for Laminated Glass and Laminated Glass

[0152] Two transparent clear glass plates (1,000 mm in length300 mm in width1.8 mm in thickness) were prepared. The glass plates and the interlayer film for a laminated glass with tungsten wires attached thereto were stacked to provide a laminate including a clear glass plate/tungsten wires/a thermochromic layer 1/a clear glass plate stacked in this order. The obtained laminate was preliminarily pressure-bonded using heating rolls at 230 C. Then, the preliminarily pressure-bonded laminate was further pressure-bonded by the heating roll method using an autoclave under the conditions of 135 C. and a pressure of 1.2 MPa for 20 minutes. Thus, a laminated glass was produced.

Example 7

[0153] (1) Preparation of Pyrogenic Layer

[0154] One transparent clear glass plate (1,000 mm in length300 mm in width1.8 mm in thickness) was prepared. Sputtering was performed on the clear glass plate using titanium as a target. The sputtering was performed under the conditions of a sputtering power of 1,500 W at medium frequencies (MF), an atmospheric gas of argon gas at a gas flow rate of 225 sccm and oxygen gas at a gas flow rate of 58 sccm, and a sputtering pressure of 0.177 Pa. Thus, a metal oxide layer formed of titanium oxide (TiO.sub.2) with a thickness of 25 nm was formed.

[0155] Subsequently, sputtering was performed on the metal oxide using zinc oxide as a target. The sputtering was performed under the conditions of a sputtering power of 1,500 W at medium frequencies (MF), an atmospheric gas of argon gas at a gas flow rate of 240 sccm and oxygen gas at a gas flow rate of 50 sccm, and a sputtering pressure of 0.170 Pa, Thus, an oxygen-deficient metal oxide layer formed of zinc oxide (ZnOx) with a thickness of 4 nm was formed.

[0156] Subsequently, sputtering was performed on the oxygen-deficient metal oxide layer using silver as a target. The sputtering was performed under the conditions of a sputtering power of 1,150 W of direct current (DC), an atmospheric gas of argon at a gas flow rate of 225 sccm, and a sputtering pressure of 0.28 Pa. Thus, a silver layer formed of silver with a thickness of 16 nm was formed.

[0157] A conductive layer was formed under the same sputtering conditions for the metal oxide layer, the oxygen-deficient metal oxide layer, and the silver layer as above, except that the thickness of each layer formed by sputtering was changed. Specifically, a conductive layer formed included, on a substrate, a metal oxide layer (25 nm)/an oxygen-deficient metal oxide layer (4 nm)/a silver layer (16 nm)/an oxygen-deficient metal oxide layer (4 nm)/a metal oxide layer (55 nm)/an oxygen-deficient metal oxide layer (4 nm)/a silver layer (16 nm)/an oxygen-deficient metal oxide layer (4 nm)/a metal oxide layer (25 nm) in this order.

[0158] The obtained conductive layer had a surface resistivity of 1.0 /.

[0159] (2) Production of Interlayer Film for Laminated Glass and Laminated Glass

[0160] One thermochromic layer 1 was prepared as in Example 1 as an interlayer film for a laminated glass, Separately, one transparent clear glass plate (1,000 mm in length300 mm in width1.8 mm in thickness) was prepared. The clear glass plate having a conductive layer formed thereon, the interlayer film for a laminated glass, and the clear glass plate were stacked to provide a laminate including a clear glass plate/a conductive layer/a thermochromic layer 1/a clear glass plate stacked in this order. The obtained laminate was preliminarily pressure-bonded using heating rolls at 230 C., Then, the preliminarily pressure-bonded laminate was further pressure-bonded by the heating roll method using an autoclave under the conditions of 135 C. and a pressure of 1.2 MPa for 20 minutes. Thus, a laminated glass was produced.

Comparative Example 1

[0161] A polyethylene terephthalate (PET) film with a thickness of 50 m as a substrate was sandwiched between two thermochromic layers 1 obtained as in Example 1, and the laminate was thermally pressure-bonded. Thus an interlayer film for a laminated glass having a laminated structure (a thermochromic layer 1/a substrate/a thermochromic layer 1) was produced. The thermal pressure-bonding was performed by the roll-to-roll process using a thermal pressure bonding laminator (MRK-650Y type available from MCK Co., Ltd.) under the conditions of a heating temperature of 75 C., a pressure for the pressure bonding of 1.0 kN, and a tension during conveyance of 20 N. The upper and lower lamination rolls used for the thermal pressure bonding were both made of rubber.

[0162] The obtained interlayer film for a laminated glass was sandwiched between two transparent clear glass plates (1,000 mm in length300 mm in width1.8 mm in thickness), thereby providing a laminate. The obtained laminate was preliminarily pressure-bonded using heating rolls at 230 C. Then, the preliminarily pressure-bonded laminate was further pressure-bonded by the heating roll method using an autoclave under the conditions of 135 C. and a pressure of 1.2 MPa for 20 minutes, Thus, a laminated glass was produced.

Comparative Example 2

[0163] (1) Preparation of Thermochromic Layer 6

[0164] To 100 parts by weight of polyvinyl butyral were added 0.5 parts by weight of a blue-black thermochromic ink, 40 parts by weight of a plasticizer, 0.5 parts by weight of a UV blocking agent, and 0.5 parts by weight of an antioxidant. They were sufficiently kneaded using a mixing roll to prepare a composition.

[0165] The polyvinyl butyral used had a hydroxy group content of 30 mol %, a degree of acetylation of 1 mol %, a degree of butyralization of 69 mol %, and an average degree of polymerization of 1,700, The thermochromic ink used was a blue-black thermochromic ink extracted from a FRIXION BALL KNOCK ballpoint pen (LFBK-23EF-BB available from Pilot Corporation). The plasticizer used was triethylene glycol di-2-ethylhexanoate (3GO), The UV blocking agent used was 2-(2-hydroxy-3-t-butyl-5-methylphenyl)-5-chlorobenzotriazole (Tinuvin326 available from BASF SE). The antioxidant used was 2,6-di-t-butyl-p-cresol (BHT).

[0166] The obtained composition was extruded from an extruder to provide a single-layer thermochromic layer 6 with a thickness of 760 m.

[0167] The obtained thermochromic layer 6 was blue at room temperature (25 C.).

[0168] (2) Production of Laminated Glass

[0169] The obtained thermochromic layer 6 alone was used as an interlayer film for a laminated glass and sandwiched between two transparent clear glass plates (1,000 mm in length300 mm in width1.8 mm in thickness), thereby providing a laminate. The obtained laminate was preliminarily pressure-bonded using heating rolls at 230 C. Then, the preliminarily pressure-bonded laminate was further pressure-bonded by the heating roll method using an autoclave under the conditions of 135 C. and a pressure of 1.2 MPa for 20 minutes. Thus, a laminated glass was produced,

[0170] (Evaluation)

[0171] The laminated glasses obtained in the examples and comparative examples were evaluated by the following methods.

[0172] Tables 1 and 2 show the results.

[0173] (1) Evaluation of Visible Light Transmittance

[0174] The visible light transmittance of the obtained laminated glass was measured by a method in conformity with JIS R 3208 using a spectrophotometer (U-4100 available from Hitachi High-Technologies Corporation), The measurement was performed at a part where the copper foil tape was not attached.

[0175] (2) Evaluation of Color Change

[0176] The electrodes protruding from the laminated glass were connected to a DC12V/4.2A power source S8JX-N05012DC (Omron Corporation) using alligator cables. In the case of the laminated glasses of Examples 6 and 7, connection was established by contacting the tungsten wire or conductive layer with alligator cables.

[0177] A voltage of 12 V was applied to the laminated glass in an atmosphere of 25 C., and the color change (color development) was visually evaluated. Then, the voltage was turned off and the laminated glass was cooled in an atmosphere of 10 C., and the color change (color fade) was visually evaluated. In this evaluation, the temperature of 10 C. was maintained until the color change was not any more observed. As a result, in the laminated glasses of Examples 1 to 4, the color change was observed over the entire surface.

[0178] In this evaluation, a contact thermometer was used to measure the temperature at the central portion of the laminated glass surface, and the color development starting temperature and the color fade starting temperature were obtained.

[0179] The laminated glasses of Comparative Examples 1 and 2 had no pyrogenic layer. The evaluation of these laminated glasses was performed by warming the environmental temperature using an air conditioner. As a result, in the laminated glasses of Comparative Examples 1 and 2, the color change was observed only locally and the change over the entire surface of the laminated glass was not observed.

[0180] Even in the case where the microcapsule pigment disclosed in Patent Literature 1 (JP 2013-159706 A) is used instead of the thermochromic ink used in the examples of the present application, it is considered that a thermochromic interlayer film for a laminated glass capable of changing its color uniformly can be produced. It is also considered that a laminated glass produced using the thermochromic interlayer film for a laminated glass and a laminated glass system including the laminated glass can be produced. The microcapsule pigment disclosed in Patent Literature 1 includes the following four components (a) to (d):

[0181] (a) an electron donative colorational organic compound;

[0182] (b) an electron acceptive compound (specific hydroxybenzoate compound);

[0183] (c) a reaction medium (reaction medium that reversibly induces an electron transfer reaction between the components (a) and (b)); and

[0184] (d) an additive (compound having a melting point of 50 C. or higher selected from alcohols, esters, ethers, ketones, and acid amides).

TABLE-US-00001 TABLE 1 Example 1 Example 2 Example 3 Example 4 Example 5 Layer structure Glass Clear glass (1.8 mm in thickness) of laminated Thermochromic Thermochromic Thermochromic Protective Thermochromic Thermochromic glass layer layer 1 layer 2 layer 3 layer 5 layer 1 (Orange (Blue-black (Yellow (Orange thermochromic ink) thermochronic ink) thermochromic ink) thermochromic ink) Pyrogenic layer Conductive layer (including pyrogenic layer, Patterned with metal oxide layer, and oxygen-deficient metal oxide layer) copper lines PET substrate PET film (50 m in thickness) Thermochromic Thermochromic Protective Thermochromic Thermochromic Thermochromic layer layer 1 layer 3 layer 4 layer 5 layer 1 (Orange (Green (Yellow (Orange thermochromic ink) thermochromic ink) thermochromic ink) thermochromic ink) Glass Clear glass (1.8 mm in thickness) Evaluation Visible light 80 85 85 80 85 transmittance (%) Color Change Orange Colorless Blue Colorless Green Colorless Yellow Colorless Orange Colorless change Color 35 40 40 35 35 development starting temperature ( C.) Color fade 5 10 10 5 5 starting temperature ( C.)

TABLE-US-00002 TABLE 2 Example 6 Example 7 Comparative Example 1 Comparative Example 2 Layer structure Glass Clear glass (1.8 mm in thickness) of laminated Thermochromic Thermochromic Thermochromic Thermochromic Thermochromic glass layer layer 1 layer 1 layer 1 layer 6 (Orange (Orange (Orange (Blue-black thermochromic ink) thermochromic ink) thermochromic ink) thermochronic ink) Pyrogenic layer Tungsten wire Conductive layer (including pyrogenic layer, metal oxide layer, and oxygen- deficient metal oxide layer) PET substrate Thermochromic layer Thermochromic layer 1 (Orange thermochromic ink) Glass Clear glass (1.8 mm in thickness) Evaluation Visible light transmittance (%) 85 85 80 80 Color Change Orange Colorless Orange Colorless (Color developed locally) (Color developed locally) change Color 35 35 35 40 development starting temperature ( C.) Color fade 5 5 5 10 starting temperature ( C.)

INDUSTRIAL APPLICABILITY

[0185] The present invention can provide a thermochromic interlayer film for a laminated glass capable of uniformly changing its color, a laminated glass produced using the thermochromic interlayer film for a laminated glass, and a laminated glass system including the laminated glass.

REFERENCE SIGNS LIST

[0186] 1 interlayer film for a laminated glass [0187] 2 pyrogenic layer [0188] 3 substrate [0189] 4 first thermochromic layer [0190] 5 second thermochromic layer