KR20030016589A - Reversible thermochromic composition and the mirror utilizing the said composition for prevention from glaring light - Google Patents

Abstract

PURPOSE: Provided is an anti-glare mirror for decreasing reflexibility of the rays of light by using a polymer-based thermochromic composition undergoing a reversible change of color when it is heated or cooled. CONSTITUTION: The thermochromic composition comprises the components of: pH-indicating color solution; buffer solution such as alkali metal hydroxides and alkali earth metal hydroxides; tuning color such as bromotimol blue(BTB), curcumin or phenolphthalein; and a polymer compound, being miscible with color solution indicating pH, such as cellulose, cellulose derivatives, polyethylene glycol or polyacrylic acid. The colorants, undergoing color change in the range of pH 7-11, are dibromo phenolsulfonphthalein, ortho-cresolphthalein, alpha-naphtholphthalein, meta-cresolsulfonphthalein, etc. The color solution is prepared by 0.001-20wt.% of colorants into alcohols such as ethyl alcohol, n-propyl alcohol and isopropyl alcohol. The composition is inserted between mirror(4) and glass(2) and changes its colors due to heat supply from heater(1) behind the mirror, resulting in decrease of the rays of light.

Description

Reversible thermochromic composition and anti-glare mirror using the same {REVERSIBLE THERMOCHROMIC COMPOSITION AND THE MIRROR UTILIZING THE SAID COMPOSITION FOR PREVENTION FROM GLARING LIGHT}

The present invention relates to a thermochromic composition which is sensitively reversibly discolored depending on temperature, and an anti-glare mirror prepared using the same. More specifically, the present invention relates to a temperature-dependent reversible thermochromic composition composed of an alcohol solution and an alcohol soluble high molecular compound of a basic pH indicator, and an anti-glare vehicle mirror using the same.

Conventionally, an electrochromic material is used as a vehicle mirror to prevent glare. When a liquid is mixed with a liquid electrolyte and an electrochromic material between a mirror surface and a glass surface, and a constant current flows, the light is changed to a dark color by a redox reaction. Techniques for exhibiting the effect of reducing these are known.

In general, the thermochromic phenomenon refers to the change in absorption wavelength due to the change of state of the material with temperature change. A reversible thermochromic material is a material that has a property of discoloring at a specified temperature, and is applied to a product requiring a temperature, warning, and dangerous temperature indication and a product that enjoys color change by using this property.

Examples of such thermochromic materials include (1) thermochromic liquid crystal materials (see, for example, US Pat. Nos. 2,800,457, 3,429,827, 3,208,951, 5,705,093, PCT / De92 / 002799, etc.), and (2) metals. The application of the crystal of a complex salt, (3) the thing using an electron donating compound (for example, US 5,352,649, 5,919,404, 5,873,932, etc.) are known.

Among them, the use of a liquid crystal compound is most widely known. When an anti-glare mirror for a vehicle is manufactured using such an electrochromic material, it is known that color scheme becomes dark to reduce reflection of light. However, the manufacturing using the liquid crystal media is expensive, and there are problems such as malfunction of the electromagnetic plate for controlling electricity at high temperature or humidity.

In addition, it is known that the pH indicator reversibly discolors depending on the temperature in the buffer, and ink, a self-deletion blackboard system using such a pH indicator is known (Dean G. Hafeman et al., J. Phys. Chem. 1993). 97, 3058-3066, US Pat. No. 5,786,838, 4,149,852, 5,294,375, etc.).

Dean's paper discloses that since hydrogen ions are reversibly dissociated from a pH indicator, dissolution of the EZ reagent into a buffer causes a temperature-dependent reversal reaction to cause discoloration at a certain temperature.

However, the composition consisting of the above-described phthaleins or fluoresceins, an electron donating organic nitrogen compound, an alcohol, and an acid amide has little color development and contains a polyhydroxy compound, a boric acid alkali metal salt, and a pH indicator pigment. The composition has a problem that the temperature is limited because the discoloration temperature is high and the response of discoloration takes a long time.

In addition, conventional thermochromic materials have low solubility in water and require microencapsulation.

As a result of preparing a composition containing a macromolecular compound solution as a support in a pH indicator dye and a gelling agent, when the pH indicator dye is dissolved and used in water-immiscible n-butyl alcohol, the butyl alcohol solution has a solubility in water. It is low, it is not uniformly mixed with an aqueous solution of a high molecular compound, and a layer separation occurs with an aqueous layer and a butyl alcohol layer, and in order to overcome this, even when shaken or stirred, the layer is separated again over time to temporarily discolor only part of the layer, or It was found that there is a problem that does not discolor at all. In addition, in the case of using polyvinyl alcohol, since the discoloration is possible only when the temperature rises to about 70 ° C., there is a problem of increasing the heating temperature. Thus, it is preferable that the support of a pH indicator pigment is soluble in a lower alcohol.

In order to solve the above problems, the present inventors have a quick response to color change due to temperature change, a high color density, and can be used by mixing with a polymer, and have excellent durability and reversible thermochromic composition. As a result of intensive studies to manufacture a mirror for preventing driver's anti-glare by using the property of discoloring the composition at a set temperature, a composition comprising a support solution buffer of a polymer compound dissolved in a pH indicator solution and a solvent miscible with the solution of the indicator After use, the inside of the mirror was put into an empty mirror and sealed, the planar heating element was attached to the rear surface of the mirror, and thus, it was found to be excellent as a vehicle mirror for preventing glare, thereby completing the present invention.

That is, the present invention provides a composition comprising a pH indicator solution and a support solution buffer of a polymer compound dissolved in a solvent miscible with the solution of the indicator.

In addition, to provide a vehicle mirror for preventing glare using the composition of the present invention.

1 shows an embodiment of a mirror for an automobile using the thermochromic composition of the present invention.

The principle of the present invention is to insert a polymer mixture using a reversible thermochromic material rather than an electrochromic material between the mirror surface and the glass surface, and then discolors in accordance with the supply of heat energy by a heater attached to the mirror surface to reduce the reflectance of light as much as possible. To give.

As described above, the colorants used in the present invention were selected from phthalein-based materials having a structure capable of thermal discoloration among organic dyes showing color change according to pH change.

The selected phthaleins are tetranitrophenol sulfone phthalein, meta-cresol sulfone phthalein (methcresol purple), ortho-cresol sulfone phthalein (cresol red), dibromodichlororophenol sulfone phthalein (bromine chlorophenol) Blue), tetrabromo-meth-cresolsulfonphthalein (bromocresol green), dichlorophenolsulfonphthalein (chlorophenol red), dibromo-ortho-cresolsulfonphthalein (bromocresol purple), dibro Monophenol sulfone phthalein (bromine phenol red), dibromo morph sulfone phthalein (bromo thymol blue), phenol sulfone phthalein (phenol red), ortho-cresol phthalein (cresol red), alpha naphthol phthalein And tetrabromosulfonphthalein (bromine phenol blue), thymol sulfonphthalein (timomol blue), phenolphthalein, thymolphthalein and these phthalein derivatives and mixtures thereof.

More preferably, dibromophenol sulfone phthalein, dibromothymol sulfone phthalein, phenol sulfone phthalein, ortho-cresol phthalein, meta-cresol sulfone phthalein, alpha-naphthol phthalein, thymol sulfon phthalein, Phthaphthalane, thymolphthalein, and mixtures thereof, and organic pigments of the phthalein-based discoloration between pH 7-11.

These organic pigments were dissolved in 0.001 to 20% by weight in low-cost alcohols such as ethyl alcohol, n-propyl alcohol and isopropyl alcohol to prepare an organic pigment solution.

Polymeric supports used to improve mechanical stability and durability of organic pigment solutions include starch, starch derivatives, cellulose, cellulose derivatives, polyvinyl alcohol, polyethylene glycol, polyvinylpyrrolidone, polyacrylic acid and its salts, polyacrylic acid, Salt crosslinkers thereof and combinations of these polymers.

More preferably, ethyl cellulose, polyvinyl alcohol, and polyvinylpyrrolidone are mentioned.

These polymers have different Tg values.

The discoloration temperature of the reversible thermochromic composition prepared by using the polymer as the polymer support is affected by the Tg value of the polymer support.

These are limited to being dissolved in a solvent having good miscibility with alcohol, which is a solvent used to prepare the selected organic pigment solution.

As a solvent used for the preparation of the polymer solution, lower alcohols such as distilled water, methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol and t-butyl alcohol; Ketones such as acetone; Ethers such as tetrahydrofuran and alkoxypolyethylene glycol; Amides such as N, N-dimethylformamide; Sulfoxides such as dimethyl sulfoxy; The mixture of distilled water and the said organic solvent, etc. are mentioned.

A polymer solution is prepared by dissolving the selected polymer support in distilled water, alcohol, or organic solvent at a ratio of 1 to 30% by weight.

The organic pigment solution prepared first is added to the polymer solution at a ratio of 0.001 to 20% by volume.

Since the organic pigments used as colorants are discolored at different pH values, one of alkali metal salts such as sodium hydroxide and potassium hydroxide, alkaline earth metal salt solutions such as magnesium hydroxide and calcium dioxide, and a buffer solution close to the discoloration pH of organic pigments. Was added to adjust the pH of the polymer solution to just before discoloration of the organic pigment or to the pH of the initial discoloration point.

A reversible thermochromic composition prepared in this manner is injected between a transparent or colored mirror bonded to a planar heating element and a transparent or colored glass or plastic plate, and prevents external leakage of the reversible thermochromic composition and contact with air and moisture. In order to prevent it from being completely isolated from the outside to create a reversible thermochromic mirror.

Hereinafter, the accompanying drawings will be described in detail.

1 shows an embodiment of a mirror for an automobile using the thermochromic composition of the present invention. In the figure, code | symbol 1 is a planar heating element, and code | symbol + and-represent an electrode. Such a planar heating element is known and is disclosed in, for example, Japanese Patent No. 219396. The mirror 4 is formed on the upper part of this heating element, and the box which consists of glass or the heat-transfer plate 2 is attached to the lower part, and attaches the box which consists of the mirror 4 and plate 3, 3 '. The shape, shape, size, and internal capacity of the box are not particularly limited, but preferably, the shape and size of a vehicle mirror currently used are the same, and the inner space of the box is preferably about 1 to 5 mm.

The anti-glare mirror of the present invention is produced by injecting the composition of the present invention into such a box mirror and sealing the inlet.

The operating temperature of the mirror of the present invention varies depending on the type of pH indicator pigment used, but when using an alkaline indicator pigment solution of the present invention and a lower alcohol soluble support such as methanol ethanol, it is usually discolored at a temperature of 60 ° C. to less than 70 ° C. Therefore, if the heat generation temperature of the surface heating element is set to about 65 to 80 ° C., when the light reaches the mirror from the headlight of the rear vehicle, the color scheme of the mirror is darkly discolored, so that the amount of reflection of the light is greatly reduced to prevent glare.

(Example)

Hereinafter, the present invention will be described in detail by way of examples. However, these examples illustrate the present invention and do not limit the scope of the present invention.

Example 1

8 g of ethyl cellulose 100 CPS and 100 ml of n-propyl alcohol were added to a 250 ml round bottom flask equipped with a stirrer, and stirred at 70 ° C. for 3 hours to prepare a clear ethyl cellulose solution.

0.8 g of phenolphthalein was dissolved in 50 ml of n-propyl alcohol to prepare a phenolphthalein solution.

2 ml of the phenolphthalein solution was added to the ethyl cellulose solution, stirred at 70 ° C. for 30 minutes, and 0.4 ml of 0.5 mol of sodium hydroxide aqueous solution was slowly added thereto, and stirred at 70 ° C. for 1 hour to give a pale pink color at room temperature. A thermochromic composition showing red color was obtained.

Example 2

Into a 250 mL round bottom flask equipped with a stirrer, 8 g of ethyl cellulose 100 CPS and 100 ml of n-propyl alcohol were added and stirred at 70 ° C. for 4 hours to prepare a transparent ethyl cellulose solution.

0.33 g of thymolphthalein was dissolved in 50 ml of n-propyl alcohol to prepare a thymolphthalein solution.

0.4 ml of thymolphthalein solution was added to the ethyl cellulose solution, stirred at 70 ° C. for 30 minutes, and then 0.6 ml of 0.5 mol of sodium hydroxide solution was slowly added thereto, and stirred at 70 ° C. for 1 hour to give colorless at room temperature. A thermochromic composition showing a blue color was obtained.

Example 3

Into a 250 mL round bottom flask equipped with a stirrer, 8 g of ethyl cellulose 100 CPS and 100 ml of n-propyl alcohol were added and stirred at 70 ° C. for 4 hours to prepare a transparent ethyl cellulose solution.

0.33 g of thymolphthalein was dissolved in 50 ml of n-propyl alcohol to prepare a thymolphthalein solution.

1.0 mL of thymolphthalein solution was added to the ethyl cellulose solution prepared above, stirred at 70 ° C. for 30 minutes, and then slowly added 0.5 mL of 0.5 mol of sodium hydroxide aqueous solution was stirred at 70 ° C. for 1 hour to give colorless at room temperature. 60 A thermochromic composition showing a blue color at 占 폚 was obtained.

Example 4

Into a 250 ml round bottom flask equipped with a stirrer, 8 g of ethyl cellulose 100 CPS and 100 ml of n-propyl alcohol were added and stirred at 70 ° C. for 4 hours to prepare a clear ethyl cellulose solution.

0.33 g of thymol blue was dissolved in 50 ml of n-propyl alcohol to prepare a thymol blue solution.

0.5 ml of thymol blue solution was added to the previously prepared ethyl cellulose solution, stirred at 60 ° C. for 30 minutes, and 0.5 ml of 0.5 mol sodium hydroxide was slowly added thereto, stirred at 70 ° C. for 1 hour to give green color at room temperature, and 65 ° C. A thermochromic composition showing a dark blue green color was obtained.

Example 5

Into a 250 ml round bottom flask equipped with a stirrer, 8 g of ethyl cellulose 100 CPS and 100 ml of n-propyl alcohol were added and stirred at 70 ° C. for 4 hours to prepare a clear ethyl cellulose solution.

0.33 g of thymol blue was dissolved in 50 ml of n-propyl alcohol to prepare a thymol blue solution.

1 ml of thymol blue solution was added to the previously prepared ethyl cellulose solution, stirred at 60 ° C. for 30 minutes, and 0.5 ml of 0.5 mol sodium hydroxide was slowly added thereto, stirred at 70 ° C. for 1 hour to give green color at room temperature, and 65 ° C. A thermochromic composition exhibiting a dark blue green color was obtained.

Example 6

8 g of ethyl cellulose 100 CPS and 100 ml of n-propyl alcohol were added to a 250 ml round bottom flask equipped with a stirrer, and stirred at 70 ° C. for 4 hours to prepare a clear ethyl cellulose solution.

0.33 g of thymol blue was dissolved in 50 ml of n-propyl alcohol to prepare a thymol blue solution.

0.8 g of phenolphthalein was dissolved in 50 ml of n-propyl alcohol to prepare a phenolphthalein solution.

0.4 ml of thymol blue solution and 0.1 ml of phenolphthalein solution were added to the previously prepared ethyl cellulose solution, and stirred at 60 ° C. for 30 minutes, and then slowly added 0.5 ml of 0.5 mol of sodium hydroxide aqueous solution was stirred at 70 ° C. for 1 hour, and blue at room temperature. And the thermochromic composition which shows purple at 65 degreeC was obtained.

Example 7

Into a 250 ml round bottom flask equipped with a stirrer, 4 g of ethyl cellulose 100 CPS and 100 ml of n-propyl alcohol were added and stirred at 70 ° C. for 4 hours to prepare a clear ethyl cellulose solution.

0.33 g of thymolphthalein was dissolved in 50 ml of n-propyl alcohol to prepare a thymolphthalein solution.

0.8 g of phenolphthalein was dissolved in 50 ml of n-propyl alcohol to prepare a phenolphthalein solution.

0.4 ml of thymolphthalein solution and 0.05 ml of phenolphthalein solution were added to the previously prepared ethyl cellulose solution, stirred at 70 ° C. for 30 minutes, and then slowly added 0.5 ml of 0.5 mol of sodium hydroxide solution, and stirred at 70 ° C. for 1 hour at room temperature. The thermochromic composition which shows light blue color and shows light purple at 65 degreeC was obtained.

Example 8

Into a 250 ml round bottom flask equipped with a stirrer, 8 g of ethyl cellulose 100 CPS and 100 ml of n-propyl alcohol were added and stirred at 70 ° C. for 4 hours to prepare a clear ethyl cellulose solution.

On the other hand, 0.33 g of thymol blue was dissolved in 50 ml of n-propyl alcohol to prepare a thymol blue solution.

0.33 g of thymolphthalein was dissolved in 50 ml of n-propyl alcohol to prepare a thymolphthalein solution.

0.4 ml of thymolphthalein solution and 0.5 ml of thymol blue solution were added to the previously prepared ethyl cellulose solution, and stirred at 70 ° C. for 30 minutes, and then 0.5 ml of 0.5 mol of sodium hydroxide solution was slowly added thereto, and stirred at 70 ° C. for 1 hour at room temperature. The thermochromic composition which shows green at and shows a green-blue color at 65 degreeC was obtained.

Example 9

Into a 250 ml round bottom flask equipped with a stirrer, 8 g of ethyl cellulose 100 CPS and 100 ml of n-propyl alcohol were added and stirred at 70 ° C. for 4 hours to prepare a clear ethyl cellulose solution.

0.33 g of thymol blue was dissolved in 50 ml of n-propyl alcohol to prepare a thymol blue solution.

0.3 g of bromothymol blue was dissolved in 100 ml of n-propyl alcohol to prepare a bromothymol blue solution.

0.5 ml of thymol blue solution and 0.1 ml of bromothymol blue solution were added to the previously prepared ethyl cellulose solution, stirred at 70 ° C. for 30 minutes, and then 0.5 ml of 0.5 mol of sodium hydroxide solution was slowly added thereto, and stirred at 70 ° C. for 1 hour at room temperature. The thermochromic composition which shows blue at and indigo blue at 65 degreeC was obtained.

Example 10

Into a 250 ml round bottom flask equipped with a stirrer, 8 g of ethyl cellulose 100 CPS and 100 ml of n-propyl alcohol were added and stirred at 70 ° C. for 4 hours to prepare a clear ethyl cellulose solution.

0.8 g of phenolphthalein was dissolved in 50 ml of n-propyl alcohol to prepare a phenolphthalein solution.

0.3 g of bromothymol blue was dissolved in 100 ml of n-propyl alcohol to prepare a bromothymol blue solution.

2.0 ml of phenolphthalein solution and 0.1 ml of bromothymol blue solution were added to the previously prepared ethyl cellulose solution. The mixture was stirred at 70 ° C. for 30 minutes, and then slowly added 0.5 ml of 0.5 mol of sodium hydroxide solution was stirred at 70 ° C. for 1 hour at room temperature. The thermochromic composition which shows indigo blue and shows the deep purple color at 60 degreeC was obtained.

Example 11

Into a 250 ml round bottom flask equipped with a stirrer, 8 g of ethyl cellulose 100 CPS and 100 ml of n-propyl alcohol were added and stirred at 70 ° C. for 4 hours to prepare a clear ethyl cellulose solution.

0.33 g of thymol blue was dissolved in 50 ml of n-propyl alcohol to prepare a thymol blue solution.

0.1 g of curcumin was dissolved in 100 ml of n-propyl alcohol to prepare a curcumin solution.

1 ml of thymol blue solution and 0.5 ml of cumulmin solution were added to the ethyl cellulose solution prepared above, and stirred at 60 ° C. for 30 minutes, and then 0.5 ml of sodium hydroxide at 0.5 mol concentration was slowly added thereto, and stirred at 70 ° C. for 1 hour at room temperature. The thermochromic composition which shows green and shows a dark blue green color at 65 degreeC was obtained.

Example 12

Into a 250 ml round bottom flask equipped with a stirrer, 8 g of ethyl cellulose 100 CPS and 100 ml of n-propyl alcohol were added and stirred at 70 ° C. for 4 hours to prepare a clear ethyl cellulose solution.

0.8 g of phenolphthalein was dissolved in 50 ml of n-propyl alcohol to prepare a phenolphthalein solution.

0.1 g of α-naphtholbenzine was dissolved in 100 ml of n-propyl alcohol to prepare α-naphtholbenzine solution.

2.0 ml of phenolphthalein solution and 0.1 ml of α-naphtholbenzine solution were added to the ethyl cellulose solution prepared above, and stirred at 70 ° C. for 30 minutes, and then slowly added 0.5 ml of 0.5 mol of sodium hydroxide solution, and stirred at 70 ° C. for 1 hour at room temperature. The thermochromic composition which shows indigo blue and shows the deep purple color at 60 degreeC was obtained.

Example 13

8 g of polyvinyl alcohol having a molecular weight of 75,000 and 100 ml of distilled water were added to a 250 ml round bottom flask equipped with a stirrer, and stirred at 80 ° C. for 4 hours to obtain a transparent polyvinyl alcohol solution.

0.8 g of phenolphthalein was dissolved in 50 ml of n-propyl alcohol to prepare a phenolphthalein solution.

2 ml of a phenolphthalein solution was added to the polyvinyl alcohol solution prepared above, and stirred at a temperature of 80 ° C. for 30 minutes. Then, 0.4 ml of 0.5 mol of sodium hydroxide solution was slowly added thereto, and stirred at 80 ° C. for 1 hour to give a light pink color at room temperature. The thermochromic composition which shows red at 68 degreeC was obtained.

Example 14

10 g of polyvinyl alcohol having a molecular weight of 10,000 and 100 ml of distilled water were added to a 250 ml round bottom flask equipped with a stirrer, and stirred at 80 ° C. for 3 hours to obtain a transparent polyvinyl alcohol solution.

0.8 g of phenolphthalein was dissolved in 50 ml of n-propyl alcohol to prepare a phenolphthalein solution.

2 ml of a phenolphthalein solution was added to the polyvinyl alcohol solution prepared above, and stirred at 80 ° C. for 30 minutes. Then, 0.6 ml of 0.5 mol of sodium hydroxide solution was slowly added thereto, and stirred at a temperature of 80 ° C. for 1 hour to give a light pink color at room temperature. The thermochromic composition which shows red at 76 degreeC was obtained.

Example 15

8 g of ethyl cellulose 100 CPS and 100 ml of N, N-dimethylacetamide were added to a 250 ml round bottom flask equipped with a stirrer, and stirred at 60 ° C. for 3 hours to prepare a transparent ethyl cellulose solution.

0.8 g of phenolphthalein was dissolved in 50 ml of n-propyl alcohol to prepare a phenolphthalein solution.

2 ml of phenolphthalein solution was added to the previously prepared ethyl cellulose solution, stirred at 60 ° C. for 30 minutes, slowly added 0.4 ml of 0.5 mol of sodium hydroxide solution, and stirred at a temperature of 60 ° C. for 1 hour to give a light pink color at room temperature. The thermochromic composition which shows red at 60 degreeC was obtained.

Example 16

8 g of ethyl cellulose 100 CPS and 100 ml of N, N-dimethylformamide were added to a 250 ml round bottom flask equipped with a stirrer, and stirred at 60 ° C. for 3 hours to prepare a transparent ethyl cellulose solution.

0.8 g of phenolphthalein was dissolved in 50 ml of n-propyl alcohol to prepare a phenolphthalein solution.

2 ml of a phenolphthalein solution was added to the ethyl cellulose solution prepared above, and stirred at 60 ° C. for 30 minutes, and then 0.4 ml of 0.5 mol of sodium hydroxide solution was slowly added thereto, stirred at a temperature of 60 ° C. for 1 hour, and light pink at room temperature. A thermochromic composition exhibiting red color at 60 ° C. was obtained.

Example 17

Ethyl cellulose 100 CPS 8g, dimethyl sulfoxide 100ml was added to a 250ml round bottom flask equipped with a stirrer and stirred at 60 ° C for 3 hours to prepare a clear ethylcellulose solution.

0.8 g of phenolphthalein was dissolved in 50 ml of n-propyl alcohol to prepare a phenolphthalein solution.

2 ml of phenolphthalein solution was added to the previously prepared ethyl cellulose solution, stirred at 60 ° C. for 30 minutes, slowly added 0.4 ml of 0.5 mol of sodium hydroxide solution, and stirred at a temperature of 60 ° C. for 1 hour to give a light pink color at room temperature. The thermochromic composition which shows red at 60 degreeC was obtained.

Example 18

Ethyl cellulose 100 CPS 8g, tetrahydrofuran 100ml was put into a 250 ml round bottom flask equipped with a stirrer and stirred at 60 ° C. for 3 hours to prepare a clear ethyl cellulose solution.

0.8 g of phenolphthalein was dissolved in 50 ml of n-propyl alcohol to prepare a phenolphthalein solution.

2 ml of phenolphthalein solution was added to the previously prepared ethyl cellulose solution, stirred at 60 ° C. for 30 minutes, slowly added 0.4 ml of 0.5 mol of sodium hydroxide solution, and stirred at a temperature of 60 ° C. for 1 hour to give a light pink color at room temperature. The thermochromic composition which shows red at 60 degreeC was obtained.

Example 19

100 ml n-propyl alcohol was placed in a 250 ml round bottom flask equipped with a stirrer.

0.8 g of phenolphthalein was dissolved in 50 ml of n-propyl alcohol to prepare a phenolphthalein solution.

2 ml of phenolphthalein solution was added to 100 ml n-propyl alcohol, which was put in a round bottom flask, and stirred at 70 ° C. for 30 minutes, and then slowly added 0.5 ml of 0.5 mol of sodium hydroxide solution was stirred at 70 ° C. for 1 hour at room temperature. The thermochromic composition which shows light pink in the color and shows red at 60 degreeC was obtained.

Example 20

1 g of ethyl cellulose 100 CPS and 100 ml of n-propyl alcohol were added to a 250 ml round bottom flask equipped with a stirrer, and stirred at 70 ° C. for 3 hours to prepare a clear ethyl cellulose solution.

0.8 g of phenolphthalein was dissolved in 50 ml of n-propyl alcohol to prepare a phenolphthalein solution.

2 ml of phenolphthalein solution was added to the previously prepared ethyl cellulose solution, stirred at 70 ° C. for 30 minutes, and slowly 0.4 ml of 0.5 mol of sodium hydroxide solution was added slowly, and stirred at 70 ° C. for 1 hour to give a pale pink color at room temperature. A thermochromic composition showing red color was obtained.

Example 21

Into a 250 mL round bottom flask equipped with a stirrer, 2 g of ethyl cellulose 100 CPS and 100 ml of n-propyl alcohol were added and stirred at 70 ° C. for 3 hours to prepare a clear ethyl cellulose solution.

0.8 g of phenolphthalein was dissolved in 50 ml of n-propyl alcohol to prepare a phenolphthalein solution.

2 ml of a phenolphthalein solution was added to the ethyl cellulose solution prepared above, and stirred at 70 ° C. for 30 minutes. Then, 0.4 ml of 0.5 mol of sodium hydroxide solution was slowly added thereto, and stirred at 70 ° C. for 1 hour to give a light pink color at room temperature. A thermochromic composition showing red color was obtained.

Example 22

Into a 250 ml round bottom flask equipped with a stirrer, 4 g of ethyl cellulose 100 CPS and 100 ml of n-propyl alcohol were added and stirred at 70 ° C. for 3 hours to prepare a transparent ethyl cellulose solution.

0.8 g of phenolphthalein was dissolved in 50 ml of n-propyl alcohol to prepare a phenolphthalein solution.

2 ml of phenolphthalein solution was added to the previously prepared ethyl cellulose solution, stirred at 70 ° C. for 30 minutes, and slowly 0.4 ml of 0.5 mol of sodium hydroxide solution was added slowly, and stirred at 70 ° C. for 1 hour to give a pale pink color at room temperature. A thermochromic composition showing red color was obtained.

Example 23

Into a 250 mL round bottom flask equipped with a stirrer, 6 g of ethyl cellulose 100 CPS and 100 ml of n-propyl alcohol were added and stirred at 70 ° C. for 3 hours to prepare a transparent ethyl cellulose solution.

0.8 g of phenolphthalein was dissolved in 50 ml of n-propyl alcohol to prepare a phenolphthalein solution.

2 ml of phenolphthalein solution was added to the previously prepared ethyl cellulose solution, stirred at 70 ° C. for 30 minutes, and slowly 0.4 ml of 0.5 mol of sodium hydroxide solution was added slowly, and stirred at 70 ° C. for 1 hour to give a pale pink color at room temperature. A thermochromic composition showing red color was obtained.

Example 24

Into a 250 ml round bottom flask equipped with a stirrer, 10 g of ethyl cellulose 100 gPS and 100 ml of n-propyl alcohol were added, and stirred at 70 ° C. for 3 hours to prepare a clear ethyl cellulose solution.

0.8 g of phenolphthalein was dissolved in 50 ml of n-propyl alcohol to prepare a phenolphthalein solution.

2 ml of phenolphthalein solution was added to the previously prepared ethyl cellulose solution, stirred at 70 ° C. for 30 minutes, and slowly 0.4 ml of 0.5 mol of sodium hydroxide solution was added slowly, and stirred at 70 ° C. for 1 hour to give a pale pink color at room temperature. A thermochromic composition showing red color was obtained.

Example 25

Into a 250 ml round bottom flask equipped with a stirrer, 12 g of ethyl cellulose 100 gPS and 100 ml of n-propyl alcohol were added, and stirred at 70 ° C. for 3 hours to prepare a clear ethyl cellulose solution.

0.8 g of phenolphthalein was dissolved in 50 ml of n-propyl alcohol to prepare a phenolphthalein solution.

2 ml of phenolphthalein solution was added to the previously prepared ethyl cellulose solution, stirred at 70 ° C. for 30 minutes, and slowly 0.4 ml of 0.5 mol of sodium hydroxide solution was added slowly, and stirred at 70 ° C. for 1 hour to give a pale pink color at room temperature. A thermochromic composition showing red color was obtained.

Example 26

15 g of ethyl cellulose 100 CPS and 100 ml of n-propyl alcohol were added to a 250 ml round bottom flask equipped with a stirrer, and stirred at 70 ° C. for 3 hours to prepare a clear ethyl cellulose solution.

0.8 g of phenolphthalein was dissolved in 50 ml of n-propyl alcohol to prepare a phenolphthalein solution.

2 ml of phenolphthalein solution was added to the previously prepared ethyl cellulose solution, stirred at 70 ° C. for 30 minutes, and slowly 0.4 ml of 0.5 mol of sodium hydroxide solution was added slowly, and stirred at 70 ° C. for 1 hour to give a pale pink color at room temperature. A thermochromic composition showing red color was obtained.

Example 27

Into a 250 mL round bottom flask equipped with a stirrer, 20 g of ethyl cellulose 100 CPS and 100 ml of n-propyl alcohol were added and stirred at 70 ° C. for 3 hours to prepare a transparent ethyl cellulose solution.

0.8 g of phenolphthalein was dissolved in 50 ml of n-propyl alcohol to prepare a phenolphthalein solution.

2 ml of phenolphthalein solution was added to the previously prepared ethyl cellulose solution, stirred at 70 ° C. for 30 minutes, and slowly 0.4 ml of 0.5 mol of sodium hydroxide solution was added slowly, and stirred at 70 ° C. for 1 hour to give a pale pink color at room temperature. A thermochromic composition showing red color was obtained.

Example 28

8 g of ethyl cellulose 100 CPS and 100 ml of n-propyl alcohol were added to a 250 ml round bottom flask equipped with a stirrer, and stirred at 70 ° C. for 3 hours to prepare a clear ethyl cellulose solution.

A phenolphthalein solution was prepared by dissolving 0.005 g of phenolphthalein in 50 ml of n-propyl alcohol.

2 ml of phenolphthalein solution was added to the previously prepared ethyl cellulose solution, stirred at 70 ° C. for 30 minutes, and slowly 0.4 ml of 0.5 mol of sodium hydroxide solution was added slowly, and stirred at 70 ° C. for 1 hour to give a pale pink color at room temperature. A thermochromic composition showing red color was obtained.

Example 29

8 g of ethyl cellulose 100 CPS and 100 ml of n-propyl alcohol were added to a 250 ml round bottom flask equipped with a stirrer, and stirred at 70 ° C. for 3 hours to prepare a clear ethyl cellulose solution.

A phenolphthalein solution was prepared by dissolving 0.025 g of phenolphthalein in 50 ml of n-propyl alcohol.

2 ml of phenolphthalein solution was added to the previously prepared ethyl cellulose solution, stirred at 70 ° C. for 30 minutes, and slowly 0.4 ml of 0.5 mol of sodium hydroxide solution was added slowly, and stirred at 70 ° C. for 1 hour to give a pale pink color at room temperature. A thermochromic composition showing red color was obtained.

Example 30

8 g of ethyl cellulose 100 CPS and 100 ml of n-propyl alcohol were added to a 250 ml round bottom flask equipped with a stirrer, and stirred at 70 ° C. for 3 hours to prepare a clear ethyl cellulose solution.

0.05 g of phenolphthalein was dissolved in 50 ml of n-propyl alcohol to prepare a phenolphthalein solution.

2 ml of phenolphthalein solution was added to the previously prepared ethyl cellulose solution, stirred at 70 ° C. for 30 minutes, and slowly 0.4 ml of 0.5 mol of sodium hydroxide solution was added slowly, and stirred at 70 ° C. for 1 hour to give a pale pink color at room temperature. A thermochromic composition showing red color was obtained.

Example 31

8 g of ethyl cellulose 100 CPS and 100 ml of n-propyl alcohol were added to a 250 ml round bottom flask equipped with a stirrer, and stirred at 70 ° C. for 3 hours to prepare a clear ethyl cellulose solution.

0.25 g of phenolphthalein was dissolved in 50 ml of n-propyl alcohol to prepare a phenolphthalein solution.

2 ml of phenolphthalein solution was added to the previously prepared ethyl cellulose solution, stirred at 70 ° C. for 30 minutes, and slowly 0.4 ml of 0.5 mol of sodium hydroxide solution was added slowly, and stirred at 70 ° C. for 1 hour to give a pale pink color at room temperature. A thermochromic composition showing red color was obtained.

Example 32

Into a 250 ml round bottom flask equipped with a stirrer, 8 g of ethyl cellulose 100 CPS and 100 ml of n-propyl alcohol were added and stirred at 70 ° C. for 3 hours to prepare a clear ethyl cellulose solution.

0.5 g of phenolphthalein was dissolved in 50 ml of n-propyl alcohol to prepare a phenolphthalein solution.

2 ml of a phenolphthalein solution was added to the ethyl cellulose solution prepared above, and stirred at 70 ° C. for 30 minutes. Then, 0.4 ml of 0.5 mol of sodium hydroxide solution was slowly added thereto, and stirred at 70 ° C. for 1 hour to give a light pink color at room temperature. A thermochromic composition showing red color was obtained.

Example 33

8 g of ethyl cellulose 100 CPS and 100 ml of n-propyl alcohol were added to a 250 ml round bottom flask equipped with a stirrer, and stirred at 70 ° C. for 3 hours to prepare a clear ethyl cellulose solution.

2.5 g of phenolphthalein was dissolved in 50 ml of n-propyl alcohol to prepare a phenolphthalein solution.

2 ml of phenolphthalein solution was added to the previously prepared ethyl cellulose solution, stirred at 70 ° C. for 30 minutes, and slowly 0.4 ml of 0.5 mol of sodium hydroxide solution was added slowly, and stirred at 70 ° C. for 1 hour to give a pale pink color at room temperature. A thermochromic composition showing red color was obtained.

Example Comparison Example Colorant Polymer matrix menstruum Colorant Discoloration start temperature (℃) * Viscosity (mm2 / s) Chromaticity ** *** Reaction time (sec) I'm after I'm after One PPT EC POH 45 1330 800 236C ~ 238C 2395C ~ 247C 57 2 TPT EC POH 60 1330 800 290C ~ 2915C 297C ~ 2985C 120 3 TPT EC POH 60 1330 800 340C ~ 341C 3282C ~ 328C 150 4 TB EC POH 55 1330 800 331C-337 3252C ~ 324C 120 5 TB EC POH 55 1330 800 320C ~ 321C 324C ~ 3262C 58 6 PPT + TB EC POH 55 1330 800 286C ~ 288C 2375C ~ 2755C 48 7 PPT + TPT EC POH 55 208 125 537C ~ 5305 535C ~ 5285C 32 8 TB + TPT EC POH 60 1330 800 3282C ~ 328C 321C ~ 323C 50 9 TB EC POH BTB 57 1330 800 3005C ~ 3015C 2935C ~ 2945C 80 10 PPT EC POH BTB 40 1330 800 2738C 2755C 50 11 TB EC POH CCM 55 1330 800 5185C 533C 70 12 PPT EC POH α-NTB 50 1330 800 2738C-2746C 2735C-2755C 65

* Starting temperature: Take a 5 ml of thermochromic material into a Φ 17 × h 63 mm vial and measure the temperature at which the color starts to dissipate at room temperature

** Color: PANTONE ^? Based on Formula Guide (1st. Edition 2001. 3rd.Printing)

*** Starting temperature: Take a 5 ml thermochromic material into a Φ 17 × h 63 mm vial and place it in a water bath heated to 80 ° C to measure the temperature at which the thermochromic material becomes completely the same color.

The symbols in the table are as follows.

PPT: phenolphthalein, TPT: thymolphenolphthalein, TB: thymol blue, BTB: bromothymol blue, CCM: curcumin, α-NTB: α-naphtholbenzein, EC: ethylcellulose, POH: propanol.

Glass Transition Temperature and Discoloration Temperature of Polymer Support Polymer conjugate Glass transition temperature (℃) Colorant Colorant Discoloration start temperature * (℃) Chromaticity ** I'm after Polyvinylpyrrolidone 175 PPT - 72 231C to 237C 2385C ~ 246C Polyvinyl alcohol 85 PPT - 60 230C ~ 236 2385C ~ 246C Ethyl cellulose 48 PPT - 45 236C ~ 238 2395C ~ 247C

* Discoloration start temperature: Measure the temperature at which discoloration starts by heating 5 ml of thermochromic material into a Φ 17 × h 63 mm vial

** Chromaticity: PANTONE ^? Based on Formula Guide (1st. Edition 2001. 3rd.Printing)

In the table, PPT is phenolphthalein

Discoloration Characteristics by Solvent Type Example Colorant * Polymer (8 g) Solvent (100 ml) Chromaticity ** Discoloration start temperature *** (℃) Discoloration After discoloration One PPT EC POH 236C ~ 238C 2395C ~ 247C 45 15 PPT EC DMA 2365C ~ 230C 2395C ~ 247C 52 16 PPT EC DMF 2365C ~ 230C 2395C ~ 247C 52 17 PPT EC DMS 2365C ~ 230C 2395C ~ 247C 48 18 PPT EC THF 2365C ~ 230C 2395C ~ 247C 50

* Coloring agent: Prepared by dissolving 0.8 g of phenolphthalene (PPT) in 50 ml of propanol.

** Chromaticity: PANTONE ^? Based on Formula Guide (1st. Edition 2001. 3rd.Printing)

*** Discoloration start temperature: Measure the temperature at which discoloration starts by taking 5 ml of thermochromic material into a Φ17 × h 63 mm vial and heating it with a water bath at room temperature.

Discoloration Characteristics by Polymer Weight Change Example Colorant * Polymer (8 g) Solvent (100 ml) Chromaticity ** Discoloration start temperature *** (℃) Discoloration After discoloration 19 PPT - Propanol 236C ~ 238C 2395C ~ 247C 42 20 PPT EC (1 g) Propanol 236C ~ 238C 2395C ~ 247C 43 21 PPT EC (2 g) Propanol 236C ~ 238C 2395C ~ 247C 43 22 PPT EC (4 g) Propanol 236C ~ 238C 2395C ~ 247C 45 23 PPT EC (6 g) Propanol 236C ~ 238C 2395C ~ 247C 45 One PPT EC (8 g) Propanol 236C ~ 238C 2395C ~ 247C 45 24 PPT EC (10 g) Propanol 236C ~ 238C 2395C ~ 247C 48 25 PPT EC (12 g) Propanol 236C ~ 238C 2395C ~ 247C 48 26 PPT EC (15 g) Propanol 236C ~ 238C 2395C ~ 247C 49 27 PPT EC (20 g) Propanol 236C ~ 238C 2395C ~ 247C 52

* Coloring agent: manufactured by dissolving 0.8 g of phenolphthalein in 50 ml of propanol

** Chromaticity: PANTONE ^? Based on Formula Guide (1st. Edition 2001. 3rd.Printing)

*** Discoloration start temperature: Measure the temperature at which discoloration starts while taking 5 ml of thermochromic material into a Φ 17 × h 63 mm vial and heating it with a water bath at room temperature.

Discoloration Characteristics by Weight Change of Coloring Agent Example Color developer weight (phenolphthalein) Solvent (Propanol) Chromaticity * Discoloration start temperature ** (℃) Discoloration After discoloration 28 0.005g 50 ml 236C ~ 2365C 236C ~ 231C 45 29 0.025 g 50 ml 236C ~ 2365C 236C ~ 231C 45 30 0.05g 50 ml 236C ~ 2365C 236C ~ 231C 45 31 0.25g 50 ml 236C ~ 2365C 231C to 2385C 45 32 0.5g 50 ml 236C ~ 2365C 2395C ~ 247C 45 One 0.8 g 50 ml 236C ~ 238C 2395C ~ 247C 45 33 2.5g 50 ml 182C-1835C 199C ~ 207C 45

* Chromaticity: PANTONE ^? Based on Formula Guide (1st. Edition 2001. 3rd.Printing)

** Discoloration start temperature: Measure the temperature at which discoloration starts by heating 5 ml of thermochromic material in a Φ17 × h 63 mm vial

※ The weight of the coloring agent added to the polymer solution in which 8 g of ethyl cellulose was dissolved in 100 ml of propanol

As described above, the thermochromic composition of the present invention is composed of a pH indicator dye solution, a buffer solution and a polymer compound compatible with the pH indicator dye solution. Moreover, if a coloring agent is mix | blended with this composition as needed, more preferable discoloration degree can be obtained. Since the composition causes heat discoloration at a temperature of less than 70 ℃, manufacturing a mirror for the vehicle by using it, the color of the mirror is darkened to reduce the reflection of light reaching the mirror from the headlight of the rear vehicle to prevent glare of the vehicle occupant It is a useful invention that can be done.

Claims (9)

pH indicator pigment solution, Buffer, Vehicle mirror filling composition for preventing glare consisting of a lower alcohol solution of a polymer support compatible with the pH indicator dye solution. The method of claim 1 wherein the colorant is added. The method of claim 1, wherein the alkaline pH indicator pigments are tetranitrophenol sulfone phthalein, meta-cresol sulfone phthalein (methcresol purple), ortho-cresol sulfone phthalein (cresol red), dibromodichlorophenol sulfone phthalate Rein (bromine chlorophenol blue), tetrabromo-meth-cresolsulfonphthalein (bromine cresol green), dichlorophenolsulfonphthalein (chlorophenol red), dibromo- ortho-cresolsulfonphthalein (bromocresol) Purple), dibromo phenol sulfone phthalein (bromine phenol red), dibromo thymol sulfone phthalein (bromo thymol blue), phenol sulfone phthalein (phenol red), ortho-cresol phthalein (cresol red), Alpha-naphtholphthalein, tetrabromosulfonphthalein (bromine phenol blue), thymolsulfonphthalein (thymol blue), phenolphthalein, thymolphthalein and one or a mixture thereof. The composition. 3. The composition according to claim 2, wherein the colorant is one selected from the group consisting of bromothymol blue, culcumin, molsulfonphthalein (thymolblue), phenolphthalein, thymolphthalein and α-naphtholbenzein. The method of claim 1, wherein the polymer support is selected from the group consisting of cellulose, derivatives of cellulose, polyvinyl alcohol, polyethylene glycol, polyvinylpyrrolidone, polyacrylic acid and salts thereof, polyacrylic acid and salt crosslinkers, and combinations of these polymers. A composition characterized by being one selected. The composition according to claim 5, wherein the polymer support is one selected from the group consisting of cellulose, cellulose derivatives, polyethylene glycol, polyacrylic acid or salts thereof, and combinations of these polymers. The composition according to claim 1, wherein the buffer is a hydroxide solution of an alkali metal and a hydroxide solution of an alkaline earth metal. 8. A composition according to claim 1 or 7, wherein the compounding amount of the buffer solution is added immediately before the start of discoloration of the pH indicator dye to the start point. An anti-glare mirror of a vehicle comprising a planar heating element attached to a rear surface of a composition of claim 1 and filled in a container of which an upper part is a mirror and a lower part is a conductor on the planar heating element.