JPH08183893A - Thermochromic resin composition - Google Patents

Abstract

PURPOSE: To obtain an inexpensive practical thermochromic resin composition which has excellent heat resistance and shows a light intensity regulating function corresponding to the wide ambient temperature range by bonding to, applying to or printing on the surface of use. CONSTITUTION: This composition comprises a mixture of a lowly viscous vinylidene fluoride/hexafluoropropylene copolymer and a polymer of a (poly)alkylene glycol mono(meth)acrylate represented by the formula, CH=CR1 O(CR2 )n OR3 (wherein R1 is hydrogen or methyl; R2 is 1-4C alkylene; R3 is 1-4C alkyl; and n is an integer of 1-25) and/or a polymer of a (poly)alkylene glycol di(meth) acrylate represented by the formula, CH2 =CR1 CO(OR2 )n OCOCR1 =CR2 (wherein R1 is hydrogen or methyl; R2 is 1-4C alkylene; R3 is 1-4C alkyl; and n is an integer of 1-25).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an LCST type (Lower Cr
itical Solution Temperature: Lower critical solution temperature
Of the thermochromic resin composition having the characteristic that the transparency changes at the transition temperature, that is, the light transmittance changes.

[0002]

2. Description of the Related Art In recent years, thermochromic resin compositions utilizing the compatibility-phase separation phenomenon of polymer blends have been proposed. In this polymer blend system, the blended polymers are uniformly mixed and transparent at the molecular level in the compatible state, but in the phase separated state, light is scattered and becomes cloudy because a micro phase separated structure is formed. A polymer blend system having an LCST type phase diagram has a thermochromic function that is transparent in one phase on the low temperature side, but becomes opaque by separating into two phases on the higher temperature side than the transition temperature.

Conventionally, in a polymer blend in which a vinylidene fluoride polymer and an acrylic acid ester polymer are combined, various systems having an LCST type phase diagram and in which reciprocal solution-phase separation occur are known. . For example,
A vinylidene fluoride-based polymer using a vinylidene fluoride-hexafluoroacetone copolymer is disclosed in JP-A-61-190546 and JP-B-63-65706.
Is disclosed in Japanese Patent Application Laid-Open Publication No. HEI 9-203 (1995).

In Japanese Patent Laid-Open No. 61-190546, a combination of vinylidene fluoride-hexafluoroacetone copolymer and a methyl acrylate polymer or an ethyl acrylate polymer is used at 190 ° C. and 17 ° C., respectively.
It is shown to have a cloud point of 0 ° C. In addition, in Japanese Patent Publication No. 63-65706, besides vinylidene fluoride-hexafluoroacetone copolymer, vinylidene fluoride polymer, vinylidene fluoride-trifluoroethylene copolymer, vinylidene fluoride-tetrafluoroethylene. Copolymers, vinylidene fluoride-hexafluoroisobutene copolymer, vinylidene fluoride-chlorotrifluoroethylene copolymer, vinylidene fluoride-vinyl fluoride copolymer, vinylidene fluoride-hexafluoropropylene copolymer, etc. It is said that the polymer also exhibits a compatibility-phase separation phenomenon (thermochromic phenomenon).

[0005]

However, when the above-mentioned combination of polymers is applied as a thermochromic resin composition, there are the following problems. That is, a vinylidene fluoride polymer using hexafluoroacetone as a raw material is a special polymer and is difficult to obtain as an industrial product. Therefore, it is necessary to synthesize it at a laboratory level, but it is not possible to synthesize it in large quantities with stable quality. Difficult,
Inevitably it becomes very expensive and not suitable for practical use. Hexafluoroacetone is a toxic substance and must be handled with extreme caution. Further, from the viewpoint of obtaining a compatibilization-phase separation phenomenon in a wider temperature range, particularly in a low temperature range where energy is smaller in terms of energy, the above-mentioned vinylidene fluoride-hexafluoroacetone copolymer and methyl acrylate are mentioned. Combined with polymer or ethyl acrylate polymer (190 ° C, 170
It is desired that the cloud point is expressed in a much lower temperature range than the cloud point (° C.). Further, from the viewpoint of heat resistance, the polymer blends that have hitherto been shown are thermoplastic and therefore may be deformed or flow by heating, and thus cannot be said to have sufficient heat resistance.

The present invention has been made in order to solve the above problems, and its object is to easily adhere to the surface to be used, adhere, coat, print, etc., in a wide temperature range, thereby easily surrounding the surface. An object of the present invention is to provide a thermochromic resin composition which has a dimming function according to temperature, is inexpensive, is practical, and has excellent heat resistance.

[0007]

In order to solve the above problems, the thermochromic resin composition according to the present invention comprises a low-viscosity vinylidene fluoride-hexafluoropropylene copolymer and the general formula CH ₂ = CR ₁ CO ( OR ₂ ) _n OR ₃ (1) (R ₁ is hydrogen or a methyl group, R ₂ is an alkylene group having 1 to 4 carbon atoms, R ₃ is an alkyl group having 1 to 4 carbon atoms, and n is 1
Represented by 25 integer) (poly) polymer of an alkylene glycol mono (meth) acrylate and / or the general formula _{CH 2 = CR 1 CO (OR} 2) n OCOCR 1 = CH 2 (2) (R 1 Is hydrogen or a methyl group, R ₂ is an alkylene group having 1 to 4 carbon atoms, R ₃ is an alkyl group having 1 to 4 carbon atoms, and n is 1
It is composed of a mixture with a polymer of (poly) alkylene glycol-based di (meth) acrylate represented by the formula:

In a preferred embodiment of the present invention, a mixture of the low-viscosity vinylidene fluoride-hexafluoropropylene copolymer and the (poly) alkylene glycol-based mono (meth) acrylate polymer is further mixed with (meth) It may be one containing a butyl acrylate polymer. Further, the mixture of the low-viscosity vinylidene fluoride-hexafluoropropylene copolymer and the (poly) alkylene glycol-based di (meth) acrylate polymer further contains a butyl (meth) acrylate polymer. , And may have a cloud point of 50 ° C. or lower.

In another preferred aspect of the present invention, the thermochromic resin composition may be crosslinked.

In the present invention, low viscosity vinylidene fluoride
The hexafluoropropylene copolymer means a polymer which is semi-liquid at room temperature, and the viscosity of a polymer which is solid at room temperature is defined by Mooney viscosity, while the low-viscosity vinylidene fluoride-hexafluoropropylene of the present invention. Copolymers include all that the concept of liquid viscosity is directly applied, that is, viscosity can be defined in units of ps (poise). Specifically, the low-viscosity vinylidene fluoride-hexafluoropropylene copolymer according to the present invention has a viscosity of 5,000 to 1 ps at 50 to 100 ° C.
It is preferably in the range of 1000 to 10 ps, and an example of such a copolymer has a viscosity of 20 at 100 ° C.
Those having a viscosity of 00 cps and a viscosity of 500 ps at 60 ° C. are available as industrial products. Viscosity 50
When it exceeds 00 ps, a polymer of (poly) alkylene glycol mono (meth) acrylate represented by the general formula (1) or (poly) represented by the general formula (2).
The compatibility with the alkylene glycol-based di (meth) acrylate polymer or the butyl acrylate polymer decreases, and it becomes difficult to obtain a uniform polymer blend. On the other hand, if it is less than 1 ps, the amount of volatile components increases, which is not preferable. Further, if it exceeds 1000 ps, it is difficult to obtain industrially, and it is difficult to provide an inexpensive thermochromic resin composition. On the other hand, below 10 ps,
Similarly, it is difficult to obtain industrial products.

General formula CH ₂ = CR ₁ CO (OR ₂ ) _n OR ₃ (1) (R ₁ is hydrogen or a methyl group, R ₂ is an alkylene group having 1 to 4 carbon atoms, and R ₃ is 1 to 4 carbon atoms. Alkyl group, n is 1
Examples of the (poly) alkylene glycol-based mono (meth) acrylate represented by the formula: methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate, propoxyethyl (meth) acrylate, butoxyethyl ( (Meth) acrylate, methoxyethylene glycol (meth) acrylate, ethoxyethylene glycol (meth) acrylate, methoxydiethylene glycol (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, methoxytriethylene glycol (meth) acrylate, ethoxytriethylene glycol (meth) Acrylate, methoxy polyethylene glycol # 200 (meth) acrylate, methoxy polyethylene glycol # 400 (meth)
Acrylate, methoxy polyethylene glycol # 60
0 (meth) acrylate, methoxy polyethylene glycol # 1000 (meth) acrylate, methoxydipropylene glycol (meth) acrylate, methoxydibutylene glycol (meth) acrylate, ethoxy polyethylene glycol # 200 (meth) acrylate, ethoxy polyethylene glycol # 400 ( (Meth) acrylate, ethoxy polyethylene glycol # 600 (meth) acrylate, ethoxy polyethylene glycol #
Examples include 1000 (meth) acrylate, ethoxydipropylene glycol (meth) acrylate, and ethoxydibutylene glycol (meth) acrylate.

The general formula CH ₂ ═CR ₁ CO (OR ₂ ) _n OCOCR ₁ ═CH ₂ (2) (R ₁ is hydrogen or a methyl group, R ₂ is an alkylene group having 1 to 4 carbon atoms, and R ₃ is An alkyl group having 1 to 4 carbon atoms, n is 1
Examples of the (poly) alkylene glycol-based di (meth) acrylate represented by the formula: methylene glycol di (meth) acrylate, ethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, Polyethylene glycol # 2
00 di (meth) acrylate, polyethylene glycol # 400 di (meth) acrylate, polyethylene glycol # 600 di (meth) acrylate, polyethylene glycol # 1000 di (meth) acrylate, propylene glycol di (meth) acrylate, butylene glycol di (meth ) Acrylate is an example.

A low-viscosity vinylidene fluoride-hexafluoropropylene copolymer, a polymer of a (poly) alkylene glycol mono (meth) acrylate represented by the general formula (1) and / or a general formula (2). (Poly)
The mixing ratio of the mixture of the alkylene glycol-based di (meth) acrylate and the polymer is low-viscosity vinylidene fluoride-
Hexafluoropropylene copolymer weight percentage from 1 to
It is preferably in the range of 50%. If the content is too small, change in transmittance of the composition cannot be expected. On the other hand, if the content is too large, it is difficult to obtain good transparency, and it is also difficult to obtain a solid composition, and the low viscosity vinylidene fluoride-hexafluoropropylene copolymer is expensive, which is disadvantageous in terms of cost. .

Polymer of (poly) alkylene glycol mono (meth) acrylate represented by the general formula (1) and / or polymer of (poly) alkylene glycol di (meth) acrylate represented by the general formula (2). By further containing a butyl (meth) acrylate polymer as a third component in the mixture with, the viscosity of the system is lowered, the composition is easily dissolved, workability during production is improved, and it is also advantageous in terms of cost. . Here, a polymer of n-butyl (meth) acrylate is preferably used as the butyl (meth) acrylate polymer. The content of the butyl (meth) acrylate polymer is the (poly) alkylene glycol mono (meth) acrylate polymer represented by the general formula (1) and / or the (poly) alkylene represented by the general formula (2). Glycol-based di (meth) acrylate polymer and (meth)
It can be contained in an arbitrary ratio with respect to the total amount with the butyl acrylate polymer.

The mixing method is not particularly limited, but an organic solvent (having a solubility parameter (SP value) of about 8 to 12,
For example, a method of dissolving the respective materials in (methyl ethyl ketone) and mixing them, and then removing the organic solvent, or a low-viscosity fluoride ((poly) alkylene glycol mono (meth) acrylate and / or (poly) alkylene glycol di (meth) acrylate) After dissolving the vinylidene chloride-hexafluoropropylene copolymer, a (poly) alkylene glycol-based mono (meth) acrylate and / or (poly)
A method of polymerizing an alkylene glycol-based di (meth) acrylate, or a low-viscosity vinylidene fluoride-hexafluoropropylene copolymer is dissolved in butyl (meth) acrylate to prepare a (poly) alkylene glycol-based mono (meth) acrylate and And / or (poly) alkylene glycol-based di (meth) acrylate are mixed, and then butyl (meth) acrylate and (poly) alkylene glycol-based mono (meth) acrylate and / or (poly)
A method of polymerizing an alkylene glycol-based di (meth) acrylate may be considered.

The thermochromic resin composition according to the present invention changes in transparency at a predetermined temperature, that is, has a cloud point at a predetermined temperature, and shows a cloud point at a relatively high temperature (exceeding 50 ° C.). However, those having a cloud point of 50 ° C. or lower are preferable. Among them, a three-component mixture containing a low-viscosity vinylidene fluoride-hexafluoropropylene copolymer and a (poly) alkylene glycol-based di (meth) acrylate polymer, and further containing a butyl (meth) acrylate polymer. In the system composition,
Those having a cloud point of 50 ° C. or lower are preferable. In this way, the compatibility-phase separation phenomenon is expressed even at low temperatures,
It enables the use of thermochromic functions at extremely low energy levels. The thermochromic resin composition of the present invention has a cloud point in a low temperature range (50 ° C. or lower) not only when it is not crosslinked but also when it is crosslinked.

Next, in another embodiment of the present invention, a thermochromic resin composition obtained by crosslinking the mixture is
Due to its three-dimensional network structure, it has excellent heat resistance. As the cross-linking method, either a chemical cross-linking method of cross-linking with a cross-linking agent or a radiation cross-linking method of cross-linking by irradiation with radiation may be used.

The cross-linking agent used for the chemical cross-linking is not particularly limited as long as it acts as a cross-linking agent, but a polyfunctional (meth) acrylic acid ester is preferable.
Examples of such polyfunctional (meth) acrylic acid esters include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, 1 , 3-
Butanediol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,10-decanediol di (meth) acrylate, trimethylolpropane tri (meth) ) Acrylate, glycerin di (meth) acrylate, EO-modified bisphenol A di (meth) acrylate, EO-modified tetrabromobisphenol A di (meth) acrylate, neopentyl glycol di (meth) acrylate, dibromo neopentyl glycol di (meth) acrylate , 2-hydroxy-1,3-di (meth) acryloxypropane, 2,2-bis [4-
((Meth) acryloxyethoxy) phenyl] propane, 2,2-bis [4-((meth) acryloxydiethoxy) phenyl] propane, 2,2-bis [4-((meth) acryloxypolyethoxy) Phenyl] propane,
Polyethylene glycol # 200 di (meth) acrylate, polyethylene glycol # 400 di (meth) acrylate, polyethylene glycol # 600 di (meth) acrylate, polyethylene glycol # 1000 di (meth) acrylate, pentaerythritol tri (meth)
Examples thereof include acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate and the like. The addition amount of this polyfunctional (meth) acrylic acid ester is a low-viscosity vinylidene fluoride-
Polymer of hexafluoropropylene copolymer and (poly) alkylene glycol mono (meth) acrylate and / or (poly) alkylene glycol di (meth)
For 100 parts by weight of the mixture of acrylate and polymer,
It is preferably 10 parts by weight or less. With such an amount of addition, the function as a crosslinking agent can be sufficiently exhibited. If the amount added is less than 0.05 parts by weight, the effect of improving heat resistance due to crosslinking will not be exhibited if the amount added is too small.

Examples of the radiation crosslinking method include electron beam crosslinking method and gamma ray crosslinking method. Although any method may be used, radiation control is easier with the electron beam crosslinking method. In the case of the electron beam cross-linking method, electron beam irradiation can be performed by a commercially available electron beam irradiation device. The electron beam dose can be arbitrarily selected as long as it does not affect the thermochromic phenomenon. Specifically 0.1-30
The range of Mrad is preferred. The smaller the irradiation dose is, the more advantageous the manufacturing cost is.However, if the irradiation dose is too small, the effect of cross-linking is not exhibited. On the other hand, if the irradiation dose is too large, it takes time to irradiate, which is disadvantageous in the manufacturing cost. There are problems such as deterioration due to lines and heat generation during irradiation. The dose is appropriately selected so as to obtain the desired degree of crosslinking depending on the application.

The general formula CH ₂ ═CR ₁ CO (OR ₂ ) _n OCOCR ₁ ═CH ₂ (2) (R ₁ is hydrogen or a methyl group, R ₂ is an alkylene group having 1 to 4 carbon atoms, and R ₃ is An alkyl group having 1 to 4 carbon atoms, n is 1
In the case of using a (poly) alkylene glycol-based di (meth) acrylate represented by the formula (1) to (25), it has a function as a cross-linking agent by itself, so that the cross-linking agent is not particularly added. A crosslinked thermochromic resin composition can be obtained.

In a thermochromic resin composition based on a polymer blend of a vinylidene fluoride-based polymer and an acrylic ester-based polymer showing a conventional LCST type phase diagram, a compatibility-phase separation phenomenon is generally clear when crosslinked. However, in the present invention, the phenomenon of compatibility-phase separation is reversibly exhibited even in the case of crosslinking as described above. It is considered that this is largely due to the effect of blending the low-viscosity vinylidene fluoride-hexafluoropropylene copolymer.

[0022]

The function of the thermochromic resin composition of the present invention is LC
It has an ST-type phase diagram and has a characteristic that transparency changes, that is, light transmittance changes at the transition temperature. By utilizing this characteristic, a display function and a dimming function function according to a temperature change are possible. When the resin composition in a cloudy state is gradually cooled to a temperature lower than a predetermined temperature and higher than a glass transition point of the resin composition, the resin composition changes from a cloudy state to a transparent state. Due to this characteristic, the above-mentioned display action,
It is possible to perform the light control function reversibly with a predetermined temperature as a boundary. It is also possible to maintain the cloudy state by rapidly cooling the cloudy resin composition to a temperature below the glass transition point. The above-mentioned predetermined temperature is selected by selecting a substance constituting a polymer-based material, and a low-viscosity vinylidene fluoride-hexafluoropropylene copolymer and a (poly) alkylene glycol mono (meta) represented by the general formula (1) ) Acrylic polymer and / or (poly) alkylene glycol-based di (meth) acrylate polymer represented by the general formula (2) and butyl acrylate polymer are arbitrarily set by selecting a mixing ratio. You can Although there is no specific measurement data of the glass transition point, it is estimated to be below 0 ° C.

Further, when a three-dimensional network structure is imparted to the thermochromic resin composition of the present invention by crosslinking, deformation and flow due to heating are suppressed and heat resistance is improved. Therefore, it is suitable for use in applications where heat resistance is particularly required. This thermochromic resin composition,
Even though it has a three-dimensional network structure, it has a white turbidity change at a temperature higher than a predetermined temperature as a boundary and has a sufficient function as a display body or a light control material. Furthermore, if the thermochromic resin composition cross-linked by the means in the cloudy state is placed at a temperature lower than a predetermined temperature and at a temperature higher than the glass transition point of the resin composition, the resin composition changes from a cloudy state to a transparent state. Change quickly. Due to such characteristics, it is possible to reversibly perform the above-mentioned display action and dimming function action with a predetermined temperature as a boundary. It is also possible to maintain the cloudy state by rapidly cooling the thermochromic resin composition in the cloudy state, which has been crosslinked by the above-mentioned means, to the glass transition point or lower. The predetermined temperature is selected by selecting a substance that constitutes a polymer-based material, and a low-viscosity vinylidene fluoride-hexafluoropropylene copolymer and a (poly) alkylene glycol mono (meth) represented by the general formula (1) are also used. It can be arbitrarily set by selecting a mixing ratio with the acrylate polymer and / or the (poly) alkylene glycol-based di (meth) acrylate polymer represented by the general formula (2) and the butyl acrylate polymer. it can.

The use of the thermochromic resin composition of the present invention is not limited to the above-mentioned display function and dimming function, and the use thereof is not limited as long as the conversion of the transparent-white turbid state can be used. For example, when it is used for a recording medium, it is extremely advantageous because it is possible to realize a transparent-white turbid state conversion at low temperature, that is, low energy. The method for raising the temperature of the thermochromic resin composition to a predetermined temperature or higher is not particularly limited, and various commonly used heaters, warm air, etc., as well as laser light, electromagnetic waves, etc. may be used. Further, when it is used as a window glass of a building, an automobile or the like, it can block sunlight rays and suppress a blinding function and an internal temperature rise. In practical use, if necessary, known weather resistance-imparting agents such as primary and secondary antioxidants, processing stabilizers, ultraviolet absorbers, light stabilizers such as hindered amines, etc. may be added, or dyes may be added. It is also possible to think of ways to improve the design.

[0025]

The following examples serve to explain the present invention more specifically. The invention is not limited by these examples.

Example 1 10 g of a low-viscosity vinylidene fluoride-hexafluoropropylene copolymer (semi-liquid at room temperature with a viscosity of 2000 cps at 100 ° C.) and methoxypolyethylene glycol # 400 acrylate as a (poly) alkylene glycol monoacrylate. 90 g and 2 g of benzoin methyl ether as a photoinitiator were mixed and irradiated with ultraviolet rays to obtain a thermochromic resin composition. When this thermochromic resin composition was heated, it became cloudy at 41 ° C. and a cloud point was confirmed. The composition had a slightly dull opacity after becoming cloudy and had a ground glass grade. When this composition was gradually cooled, it returned to a transparent state.

Example 2 20 g of low viscosity vinylidene fluoride-hexafluoropropylene copolymer, methoxypolyethylene glycol # 4
A thermochromic resin composition was obtained in the same manner as in Example 1 except that the amount of 00 acrylate was 80 g. When this thermochromic resin composition was heated, it became cloudy at 46 ° C. and a cloud point was confirmed. When this composition was gradually cooled, it returned to a transparent state.

Example 3 30 g of low-viscosity vinylidene fluoride-hexafluoropropylene copolymer, methoxypolyethylene glycol # 4
A thermochromic resin composition was obtained in the same manner as in Example 1 except that the amount of 00 acrylate was 70 g. When this thermochromic resin composition was heated, it became cloudy at 43 ° C. and a cloud point was confirmed. When this composition was gradually cooled, it returned to a transparent state.

Example 4 50 g of low viscosity vinylidene fluoride-hexafluoropropylene copolymer, methoxypolyethylene glycol # 4
A thermochromic resin composition was obtained by the same treatment as in Example 1 except that the amount of 00 acrylate was changed to 50 g. It was confirmed that this thermochromic resin composition already had a little opacity at room temperature, and became more opaque when heated and showed a cloud point of 30 ° C. or lower. When this composition was gradually cooled to room temperature, it returned to the initial state.

Example 5 50 g of a low-viscosity vinylidene fluoride-hexafluoropropylene copolymer (semi-liquid at room temperature with a viscosity of 2000 cps at 2000 cps) was used as polyethylene glycol # 400 as a (poly) alkylene glycol diacrylate.
50 g of diacrylate and 2 g of benzoin methyl ether as a photoinitiator were mixed and irradiated with ultraviolet rays to obtain a thermochromic resin composition. When this thermochromic resin composition was heated, it became cloudy at 42 ° C. and a cloud point was confirmed. Put this resin composition in methyl ethyl ketone 24
When left for a time, a gel was confirmed, and it was confirmed that this thermochromic resin composition was crosslinked. It was also found that the thermochromic resin composition has good heat resistance and shows no deformation or flow even when heated. When this thermochromic resin composition was gradually cooled, it returned to a transparent state.

Example 6 50 g of polyethylene glycol # 600 diacrylate as (poly) alkylene glycol diacrylate
Was treated in the same manner as in Example 5 except that was used to obtain a thermochromic resin composition. When this thermochromic resin composition was heated, it became cloudy at 38 ° C. and a cloud point was confirmed. When this resin composition was placed in methyl ethyl ketone and allowed to stand for 24 hours, a gel was confirmed, and it was confirmed that this thermochromic resin composition was crosslinked. It was also found that the thermochromic resin composition has good heat resistance and shows no deformation or flow even when heated. When this thermochromic resin composition was gradually cooled, it returned to a transparent state.

Example 7 30 g of a low-viscosity vinylidene fluoride-hexafluoropropylene copolymer (semi-liquid at room temperature with a viscosity of 2000 cps at 2000 cps) and methoxypolyethylene glycol # 400 acrylate as a (poly) alkylene glycol monoacrylate. 70 g, benzoin methyl ether 2 g as a photoinitiator, and tripropylene glycol diacrylate 1 g as a cross-linking agent were mixed and irradiated with ultraviolet rays to obtain a thermochromic resin composition. When this thermochromic resin composition was heated, it became cloudy at 49 ° C. and a cloud point was confirmed. When this resin composition was placed in methyl ethyl ketone and allowed to stand for 24 hours, a gel was confirmed, and it was confirmed that this thermochromic resin composition was crosslinked. It was also found that the thermochromic resin composition has good heat resistance and shows no deformation or flow even when heated. When this thermochromic resin composition was gradually cooled, it returned to a transparent state.

Example 8 30 g of a low-viscosity vinylidene fluoride-hexafluoropropylene copolymer (semi-liquid at room temperature with a viscosity of 2000 cps at 100 ° C.) was dissolved in 70 g of n-butyl acrylate to prepare a (poly) alkylene glycol system. 10 g of methoxy polyethylene glycol # 400 acrylate as a monoacrylate and 2 g of benzoin methyl ether as a photoinitiator were mixed and irradiated with ultraviolet rays to obtain a thermochromic resin composition. When this thermochromic resin composition was heated, it became cloudy at 45 ° C. and a cloud point was confirmed. When this composition was gradually cooled, it returned to a transparent state.

Example 9 A thermochromic resin composition was obtained by the same procedure as in Example 8 except that 40 g of n-butyl acrylate and 40 g of methoxypolyethylene glycol # 400 acrylate were used. When this thermochromic resin composition was heated, it became cloudy at 51 ° C. and a cloud point was confirmed. When this thermochromic resin composition was gradually cooled, it returned to a transparent state.

Example 10 A thermochromic resin composition was obtained by the same procedure as in Example 8 except that 10 g of n-butyl acrylate and 70 g of methoxypolyethylene glycol # 400 acrylate were used. When this thermochromic resin composition was heated, it became cloudy at 47 ° C. and a cloud point was confirmed. When this thermochromic resin composition was gradually cooled, it returned to a transparent state.

Example 11 30 g of a low-viscosity vinylidene fluoride-hexafluoropropylene copolymer (semi-liquid at room temperature with a viscosity of 2000 cps at 100 ° C.) was dissolved in 70 g of n-butyl acrylate to prepare a (poly) alkylene glycol system. 10 g of polyethylene glycol # 400 diacrylate as diacrylate and benzoin methyl ether 2 as photoinitiator
The mixture was mixed with g and irradiated with ultraviolet rays to obtain a thermochromic resin composition. When this thermochromic resin composition was heated, it became cloudy at 43 ° C. and a cloud point was confirmed. When this resin composition was placed in methyl ethyl ketone and allowed to stand for 24 hours, a gel was confirmed, and it was confirmed that this thermochromic resin composition was crosslinked. It was also found that the thermochromic resin composition has good heat resistance and shows no deformation or flow even when heated. When this thermochromic resin composition was gradually cooled, it returned to a transparent state.

Example 12 Example 11 was repeated except that 10 g of n-butyl acrylate and 70 g of polyethylene glycol # 600 diacrylate were used as the (poly) alkylene glycol diacrylate.
A thermochromic resin composition was obtained by the same treatment as described above.
It was confirmed that this thermochromic resin composition already had a little opacity at room temperature, and became more opaque when heated and showed a cloud point of 30 ° C. or lower. When this resin composition was placed in methyl ethyl ketone and allowed to stand for 24 hours, a gel was confirmed, and it was confirmed that this thermochromic resin composition was crosslinked. It was also found that the thermochromic resin composition has good heat resistance and shows no deformation or flow even when heated. When this thermochromic resin composition was gradually cooled to room temperature, it returned to the initial state.

Example 13 30 g of a low-viscosity vinylidene fluoride-hexafluoropropylene copolymer (semi-liquid at room temperature and a viscosity of 2000 cps at room temperature) of 30 g was dissolved in 70 g of n-butyl acrylate to prepare a (poly) alkylene glycol-based compound. 10 g of methoxy polyethylene glycol # 400 acrylate as a monoacrylate, 2 g of benzoin methyl ether as a photoinitiator, and 1 g of tripropylene glycol diacrylate as a crosslinking agent were mixed and irradiated with ultraviolet rays to obtain a thermochromic resin composition. When this thermochromic resin composition was heated, it became cloudy at 44 ° C. and a cloud point was confirmed. Put this resin composition in methyl ethyl ketone 24
When left for a time, a gel was confirmed, and it was confirmed that this thermochromic resin composition was crosslinked. It was also found that the thermochromic resin composition has good heat resistance and shows no deformation or flow even when heated. When this thermochromic resin composition was gradually cooled, it returned to a transparent state.

[0039]

As described above, according to the present invention, the display according to the ambient temperature can be easily performed by adhering, coating, printing or the like on the surface to be used, and the temperature change can be achieved even when used alone. It is possible to provide an inexpensive and practical thermochromic resin composition having a light control function according to the above and capable of exhibiting a cloud point in a low temperature range. Further, the thermochromic resin composition obtained by crosslinking with a crosslinking agent can be provided with excellent heat resistance.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location C08L 33/14 LJD

Claims (4)

[Claims] 1. A low-viscosity vinylidene fluoride-hexafluoropropylene copolymer and the general formula CH ₂ ═CR ₁ CO (OR ₂ ) _n OR ₃ (R ₁ is hydrogen or a methyl group, R ₂ has 1 to 1 carbon atoms). 4, an alkylene group, R ₃ is an alkyl group having 1 to 4 carbon atoms, and n is 1
Represented by 25 integer) (poly) polymer of an alkylene glycol mono (meth) acrylate and / or the general formula _{CH 2 = CR 1 CO (OR} 2) n OCOCR 1 = CH 2 (R 1 is hydrogen or Methyl group, R ₂ is an alkylene group having 1 to 4 carbon atoms, R ₃ is an alkyl group having 1 to 4 carbon atoms, and n is 1
(An integer of 25), a thermochromic resin composition comprising a mixture with a (poly) alkylene glycol-based di (meth) acrylate polymer. 2. A mixture of the low-viscosity vinylidene fluoride-hexafluoropropylene copolymer and the polymer of the (poly) alkylene glycol mono (meth) acrylate further contains a butyl (meth) acrylate polymer. The thermochromic resin composition according to claim 1, wherein 3. A mixture of the low-viscosity vinylidene fluoride-hexafluoropropylene copolymer and the (poly) alkylene glycol-based di (meth) acrylate polymer further contains a butyl (meth) acrylate polymer. The thermochromic resin composition according to claim 1, wherein the thermochromic resin composition has a cloud point of 50 ° C. or lower. 4. The thermochromic resin composition is crosslinked, according to any one of claims 1 to 3.
The thermochromic resin composition according to item.