阅读说明：本技术 热致变色颜料组合物 (Thermochromic pigment compositions ) 是由 C·德布拉威尔 A-L·达米奥诺 A·布尔克 F·弗洛诺 G·肖莱 于 2018-04-24 设计创作，主要内容包括：本发明涉及一种热致变色颜料组合物,所述热致变色颜料组合物包括：(A)至少一种电子供体有机染料化合物,(B)至少一种电子受体化合物和(C)至少一种对应于下式(I)的化合物,其中：X为O或单键,Z为COO或OCO,R<Sub>1</Sub>为O-烷基或(CH<Sub>2</Sub>)<Sub>m</Sub>CH<Sub>3</Sub>,-R<Sub>2</Sub>为OCO(CH<Sub>2</Sub>)<Sub>n</Sub>CH<Sub>3</Sub>或H,-y＝0-3,-m＝12-18,-n＝12-18,-p＝8-18,并且条件是,在X为O时,y不为0。本发明还涉及包括根据本发明的分解物的热致变色颜料微胶囊,涉及包括这种热致变色颜料微胶囊的油墨组合物并且最后涉及包括这种油墨组合物的书写工具。<Image he="425" wi="700" file="DDA0002192210190000011.GIF" imgContent="drawing" imgFormat="GIF" orientation="portrait" inline="no"></Image>(The present invention relates to a thermochromic pigment composition comprising: (A) at least one electron donor organic dye compound, (B) at least one electron acceptor compound and (C) at least one compound corresponding to the following formula (I) wherein: x is O or a single bond, Z is COO or OCO, R 1 Is O-alkyl or (CH) 2 ) m CH 3 ，‑R 2 Is OCO (CH) 2 ) n CH 3 Or H, -y-0-3, -m-12-18, -n-12-18, -p-8-18, and with the proviso that, when X is O, y is not 0. The invention also relates to thermochromic pigment microcapsules comprising the decomposition product according to the invention, to ink compositions comprising such thermochromic pigment microcapsules and finally to writing instruments comprising such ink compositions.)

1. A thermochromic pigment composition comprising:

(A) at least one electron-donor dye compound,

(B) at least one electron acceptor compound, and

(C) at least one compound corresponding to the following formula (I):

wherein:

x represents O or a single bond,

z represents COO or OCO,

R₁represents O-alkyl or (CH)₂)_mCH₃，

R₂Represents OCO (CH)₂)_nCH₃Or a combination of H and a nitrogen atom,

y＝0-3，

m＝12-18，

n＝12-18，

p is 8-18, and

provided that when X is O, y is not equal to 0.

2. The composition of claim 1, wherein the compound of formula (I) corresponds to the following formula (I)_a)：

Wherein:

x represents O or a single bond,

z represents COO or OCO,

R₁represents O-C_1-6Alkyl or (CH)₂)_mCH₃，

y＝0-3，

m is 12 to 18, and

p＝8-18。

3. the composition of claim 2, wherein theFormula (I)_a) Is wherein:

x represents a single bond,

z represents an OCO (oxygen-free radical,

R₁is represented by (CH)₂)_mCH₃，

y＝0，

m is 12 to 18, and

a compound of p-8-18.

4. The composition according to any one of claims 1 to 3, wherein the compound (A) is selected from the group consisting of 3- (4-diethylamino-2-ethoxyphenyl) -3- (1-ethyl-2-methylindol-3-yl) -4-azaphthalide (blue 63, CAS number: 69898-40-4), 2'- (dibenzylamino) -6' - (diethylamino) fluoran (CAS number: 34372-72-0), N-dimethyl-4- [2- [2- (octyloxy) phenyl ] -6-phenyl-4-pyridinyl ] aniline (yellow CK37, Cas number: 144190-25-0), 7- (4-diethylamino-2-hexyloxyphenyl) -7- (1-ethyl-2-yl) -methyl-1H-indol-3-yl) -7H-furo [3,4-b ] pyridin-5-one (blue 203, Cas number: 98660-18-5), 2- (2, 4-dimethylphenylamino) -3-methyl-6-diethylaminofluoran (black 15, Cas number: 36431-22-8) and 3, 3-bis- (1-butyl-2-methyl-indol-3-yl) -3H-isobenzofuran-1-one (red 40, Cas number: 50292-91-6).

5. The composition according to any one of claims 1 to 4, wherein the compound (B) is selected from the group consisting of 2, 2-bis (4-hydroxy-3-methylphenyl) propane (bisphenol C, CAS number: 79-97-0), 4-hexyl-1, 3-dihydroxybenzene (4-hexylresorcinol, CAS number: 136-77-6), 4 '-cyclohexylidenebisphenol (BPZ, CAS number: 843-55-0), 4' - (1-phenylethylidene) bisphenol (CAS number: 1571-75-1), 2 '-dihydroxybiphenyl (CAS number: 1806-29-7), 4' - (1, 4-phenylenediisopropylidene) bisphenol (CAS number: 2167-51-3), 1, 1-bis (4-hydroxy-3-methylphenyl) cyclohexane (CAS number: 2362-14-3), 9-bis (4-hydroxyphenyl) fluorene (CAS number: 3236-71-3), 4' - (1, 3-phenylenediisopropylidene) bisphenol (CAS number: 13595-25-0), 1,1, 1-tris (4-hydroxyphenyl) ethane (CAS number: 27955-94-8), 4' - (2-ethylhexylidene) diphenol (CAS number: 74462-02-5), and a, a, a ' -tris (4-hydroxyphenyl) -1-ethyl-4-isopropylbenzene (CAS number: 110726-28-8).

6. Thermochromic pigment microcapsules comprising a composition according to claims 1 to 5.

7. An ink composition containing the thermochromic pigment microcapsules according to claim 6.

8. A writing instrument containing the ink composition according to claim 7.

9. The writing instrument of claim 8 selected from the group consisting of a friction erasable ink ball point pen.

Background

Thermochromic pigment compositions exhibit reversible bleaching properties associated with changes in temperature. These compositions are used when the ink marks need to be erased repeatedly.

The thermochromic effect of the ink is achieved using three compounds:

(A) at least one electron donor or leuco organic dye compound,

(B) at least one electron acceptor or developer compound, and

(C) at least one compound acting as a reaction environment that can drive reversible electron acceptance/donation attributable to the compounds (a) and (B) or the temperature change modifier.

The change in temperature reversibly decolorizes or colors the ink. Thus, an increase in heat will cause ink erasure, while cooling will cause ink to appear. These variations follow the schematic diagram in fig. 1. In this schematic, the temperature at which the color starts to fade is T3, the temperature at which the ink color disappears completely is T4, and TG is an intermediate temperature between T3 and T4. On the other hand, the temperature at which the ink starts to recover is T2, the temperature at which the ink completely recovers is T1, and TH is an intermediate temperature between T1 and T2. The range between (TH) and (TG) is referred to as a color change hysteresis width (Δ H).

Surprisingly, the inventors have found that specific compounds can be used as reaction environment in thermochromic pigment compositions which make it possible to prepare thermochromic pigment microcapsules exhibiting optimal condensation and crystallization temperatures corresponding to the discoloration and re-coloration temperatures of these compositions, respectively. Thus, the compounds of the present invention exhibit many advantages for use as change modifiers and several advantages for use as temperature change modifiers in thermochromic inks: the compounds exhibit significant hysteresis characteristics and extremely high color contrast between the colored and bleached states. Furthermore, the novel compounds of the present invention have the advantage of being able to be prepared by ecological procedures, meaning from the recovered bio-based product 3-pentadecylphenol taken from cashew production waste.

Disclosure of Invention

According to a first aspect, the object of the present invention is a composition of thermochromic pigments, said composition comprising:

(A) at least one electron-donor dye compound,

(B) at least one electron acceptor compound, and

(C) at least one compound corresponding to the following formula (I):

wherein:

x represents O or a single bond,

-Z represents COO or OCO,

-R₁represents O-alkyl or (CH)₂)_mCH₃，

-R₂Represents OCO (CH)₂)_nCH₃Or a combination of H and a nitrogen atom,

-y＝0-3，

-m＝12-18，

-n＝12-18，

-p is 8-18, and

provided that when X is O, y is not equal to 0.

In the sense of the present invention:

-when Z ═ OCO: having oxygen atoms bound to radicals (CH)₂)_yAnd the carbonyl group is linked to the Chain (CH)₂)_pCH₃And is and

-when Z ═ COO: attachment of the carbonyl group to the Chain (CH)₂)_yAnd the oxygen atom is linked to the Chain (CH)₂)_pCH₃。

In the above formula (I), X is preferably a single bond, and Z preferably represents OCO.

In formula (I) above, y may be independently selected from one of the following integers: 0. 1,2 or 3.

In the above formula (I), m may be independently selected from one of the following integers: 12. 13, 14, 15, 16, 17 or 18.

In formula (I) above, n may be independently selected from one of the following integers: 12. 13, 14, 15, 16, 17 or 18.

In formula (I) above, p may be independently selected from one of the following integers: 8. 9, 10, 11, 12, 13, 14, 15, 16, 17 or 18.

According to a preferred embodiment, the compounds (C) of the invention correspond to the following formula (I)_a)：

Wherein:

x represents O or a single bond,

-Z represents COO or OCO,

-R₁represents O-C_1-6Alkyl or (CH)₂)_mCH₃，

-y＝0-3

-m is 12 to 18, and

-p＝8-18。

advantageously, in the formula (I) according to the invention_a) In which X isA single bond, Z preferably represents OCO, and y ═ 0.

Advantageously, in the formula (I) according to the invention_a) In, R₁Is represented by (CH)₂)_mCH₃。

According to an even more preferred embodiment, in the above formula (I)_a) The method comprises the following steps:

-X is a single bond,

-Z represents an OCO,

-R₁is represented by (CH)₂)_mCH₃，

-y＝0

-m is 12 to 18, and

-p＝8-18。

the compounds of formula (I) of the present invention can be synthesized following four different synthetic routes.

The first synthetic pathway responds to the following reaction scheme:

in this first synthetic route, the alcohol is dissolved together with the catalyst in an aprotic polar solvent such as Tetrahydrofuran (THF). The catalyst is preferably a volatile base such as triethylamine. The mixture is kept cool at a temperature of-20 ℃ to 20 ℃, preferably 0 ℃ to 20 ℃. Immersing the mixture in ice bath or solid CO in solvent such as acetone or ethanol₂The bath was kept cool. Advantageously, the mixture is rendered inert by the addition of nitrogen. The acid chloride is then added slowly, preferably dropwise, for 15 to 60 minutes, preferably 30 minutes. The alcohol to acid chloride ratio used is preferably from 1.1:1 to 1:1.1, ideally 1:1. The temperature is then raised to room temperature (25 ℃) and the mixture is kept at this temperature while stirring for 1 to 3 hours, preferably for 2 hours. The compound of formula (I) obtained is then purified by recrystallization.

The second synthetic pathway corresponds to the following reaction scheme:

in this second synthesis route, the condensation point of the alcohol is below 60 ℃ and acts as a solvent. The alcohol is used in excess, preferably with an alcohol to carboxylic acid ratio of 1.5:1 to 3:1, ideally 2: 1. The alcohol and carboxylic acid mixture is heated in the presence of a catalyst at a temperature in the range of 120 ℃ to 200 ℃ (and preferably 140 ℃ to 160 ℃) under reduced pressure (preferably 200 mbar to 800 mbar) until the acid is completely consumed. The catalyst is preferably a water-soluble acid, such as p-toluenesulfonic acid. The compound of formula (I) obtained is then purified by recrystallization.

The third synthesis pathway corresponds to the following reaction scheme:

in the third synthesis route, the condensation point of the alcohol is below 60 ℃ and acts as a solvent. The alcohol is used in excess, preferably with an alcohol to aromatic acid ratio of 1.5:1 to 3:1, ideally 2: 1. The mixture of alcohol and aromatic acid is heated under reduced pressure (preferably 200 mbar to 800 mbar) in the presence of a catalyst at a temperature in the range of 120 ℃ to 200 ℃ (and preferably 140 ℃ to 160 ℃) until the acid is completely consumed. The catalyst is preferably a water-soluble acid, such as p-toluenesulfonic acid. The compound of formula (I) is then purified by recrystallization.

The fourth synthetic pathway responds to the following reaction scheme:

in the fourth synthesis route, the alcohol is dissolved together with the catalyst in an aprotic polar solvent such as Tetrahydrofuran (THF). The catalyst is preferably a volatile base such as triethylamine. The mixture is kept cool at a temperature of-20 ℃ to 20 ℃, preferably 0 ℃ to 20 ℃. Immersing the mixture in ice bath or solid CO in solvent such as acetone or ethanol₂The bath was kept cool. Advantageously, the mixture is rendered inert by the addition of nitrogen. The acid chloride is then added slowly, preferably dropwise,for 15 to 60 minutes, preferably 30 minutes. The alcohol to acid chloride ratio used is preferably from 1.1:1 to 1:1.1, ideally 1:1. The temperature is then raised to room temperature (25 ℃) and the mixture is kept at this temperature while stirring for 1 to 3 hours, preferably for 2 hours. The compound of formula (I) obtained is then purified by recrystallization.

The compounds of formula (I) of the invention are preferably selected from the following compounds:

the compounds of formula (I) of the invention may vary from 20 ℃ to 80 ℃, preferably from 30 ℃ to 80 ℃, ideally from 40 ℃ to 70 ℃. It is this optimum condensation temperature that makes the compounds of formula (I) of the present invention ideal compounds with the desired properties for use as temperature change modifiers in thermochromic pigment compositions.

In the thermochromic pigment compositions of the present invention, the weight percentages of compounds (A), (B), and (C) vary based on the nature and concentration of each of these compounds.

The weight percentage of the electron donor dye compound (a) compared to the total weight of the thermochromic pigment composition may vary from 1 to 10 weight%, preferably from 1 to 6 weight%, ideally from 2 to 4 weight%.

The weight percentage of the electron acceptor compound (B) may vary from 1 to 20 wt%, preferably from 1 to 14 wt%, ideally from 4 to 10 wt%, relative to the total weight of the thermochromic pigment composition.

The weight percentage of compound (C) of formula (I) acting as reaction environment may vary from 70 to 98% by weight, preferably from 80 to 98% by weight, ideally from 86 to 94% by weight, with respect to the total weight of the thermochromic pigment composition.

Thus, the thermochromic pigment compositions of the present invention may comprise:

(A) from 1 to 10% by weight, preferably from 1 to 6% by weight and ideally from 2 to 4% by weight, of at least one electron donor organic compound,

(B) from 1% to 20%, preferably from 1% to 14% and ideally from 4% to 10% by weight of at least one electron acceptor compound, and

(C) from 70% to 98% by weight, preferably from 80% to 98% by weight and ideally from 86% to 94% by weight of at least one compound corresponding to formula (I).

According to one embodiment, the thermally changeable pigment composition of the present invention comprises:

(A)2 to 4% by weight of at least one electron donor organic compound,

(B)4 to 10% by weight of at least one electron acceptor compound, and

(C) from 86% to 94% by weight of at least one compound corresponding to formula (I).

Advantageously, the thermochromic pigment compositions of the present invention exhibit a color change hysteresis width (Δ H) after encapsulation in the range of from 20 ℃ to 80 ℃, preferably from 30 ℃ to 80 ℃ and ideally from 40 ℃ to 70 ℃.

As the electron donor organic compound dye (A), conventionally known compounds such as diphenylmethane phthalide, phenylindolylphthalide, indolylphthalide, diphenylmethane azaphthalide, phenylindolylazabelphthalide, fluoran, styrylquinoline and diazahrhodamine lactone (diazahododiamine lactone) can be cited, and two examples of these compounds are as follows.

The electron donor organic compound dye (A) may also be selected from 3- (4-diethylamino-2-ethoxyphenyl) -3- (1-ethyl-2-methylindol-3-yl) -4-azaphthalide (blue color 63, CAS number: 69898-40-4), 3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalate (CAS number: 1552-42-7), 2' -chloro-6 ' - (diethylamino) -3' -methylfluorane (CAS number: 21121-62-0), 6' - (diethylamino) -1,3' -dimethylfluorane (CAS number: 21934-68-9), 2-chloro-6- (diethylamino) -fluorane (CAS number: 26567-23-7), 3-diethylaminobenzofluoran (CAS number: 26628-47-7), 3',6' -bis (diethylamino) -2- (4-nitrophenyl) spiro [ isoindole-1, 9' -xanthen ] -3-one (CAS number: 29199-09-5), 2-phenylamino-3-methyl-6-diethylaminofluoran (CAS number: 29512-49-0), 2' - (dibenzylamino) -6' - (diethylamino) fluoran (CAS number: 34372-72-0), 2- (2, 4-dimethylphenylamino) -3-methyl-6-diethylaminofluoran (Black 15, CAS number: 36431-22-8), 3- (1, 2-dimethyl-3-indolyl) -3- [4- (diethylamino) -2-methylphenyl ] phthalide (CAS No.: 36499-49-7), 3',6' -dimethoxyfluoran (CAS No.: 36886-76-7), 3-bis- (1-butyl-2-methyl-indol-3-yl) -3H-isobenzofuran-1-one (red 40, CAS No.: 50292-91-6), 3-bis- (2-methyl-1-octyl-1H-indol-3-yl) -3H-isobenzofuran-1-one (CAS No.: 50292-95-0), 2 '-anilino-6' - [ ethyl (p-tolyl) amino ] -3 '-methylspiro [ isobenzofuran-1 (3H),9' - [9H ] xanthen ] -3-one (CAS No.: 59129-79-2), 3- (N-ethyl-N-isopentylamino) -6-methyl-7-anilinofluorene (CAS No.: 70516-41-5), 3- [4[ (diethylamino) phenyl ] -3- (1-ethyl-2-methyl-1H-indol-3-yl) phthalide (CAS number: 75805-17-3), 2'- (2-chloroanilino) -6' - (dibutylamino) fluoran (CAS No.: 82137-81-3), 2-phenylamino-3-methyl-6-dibutylamino fluoran (CAS No.: 89331-94-2), 3- (1-butyl-2-methyl-1H-indol-3-yl) -6- (dimethylamino) -3- [4- (dimethylamino) phenyl ] -3- (1(3H) -isobenzofuranone (CAS number: 92453-31-1), 7- (4-diethylamino-2-hexyloxyphenyl) -7- (1-ethyl-2-methyl-1H-indol-3-yl) -7H-furo [3,4-b ] pyridin-5-one (blue 203, CAS number: 98660-18-5), 7-bis [4 (diethylamino) -2-ethoxyphenyl ] furo [3,4-b ] pyridin-5-one (CAS number: 132467-74-4), N-dimethyl-4- [2- [2 (octyloxy) phenyl ] -6-phenyl-4-pyridinyl ] aniline (yellow CK37, CAS number: 144190-25-0), 3- (2, 2-bis (1-ethyl-2-methylindol-3-yl) vinyl) -3- (4-diethylaminophenyl) -phthalide (CAS number: 148716-90-9).

Preferably, the electron donor organic compound dye (A) is selected from the group consisting of 3- (4-diethylamino-2-ethoxyphenyl) -3- (1-ethyl-2-methylindol-3-yl) -4-azaphthalide (blue color 63, CAS number: 69898-40-4), 2'- (dibenzylamino) -6' - (diethylamino) fluoran (CAS number: 34372-72-0), N-dimethyl-4- [2- [2- (octyloxy) phenyl ] -6-phenyl-4-pyridinyl ] aniline (yellow CK37, CAS number: 144190-25-0), 7- (4-diethylamino-2-hexyloxyphenyl) -7- (1-ethyl-2-methyl-1H-indole Indol-3-yl) -7H-furo [3,4-b ] pyridin-5-one (blue 203, CAS number: 98660-18-5), 2- (2, 4-dimethylphenylamino) -3-methyl-6-diethylaminofluoran (black 15, CAS No.: 36431-22-8) and 3, 3-bis- (1-butyl-2-methyl-indol-3-yl) -3H-isobenzofuran-1-one (red 40, CAS No.: 50292-91-6).

As the electron acceptor compound (B), a non-exhaustive list of compounds having an active proton, such as compounds having a phenolic hydroxyl group (monophenol or polyphenol), derivatives thereof having a substituent (such as an alkyl group, an aryl group, an acyl group, an alkoxycarbonyl group, a carboxyl group, an ester thereof, an amine group, or a halogen atom), and condensed phenol resins such as bisphenol or triphenol, can be provided.

In the sense of the present invention, the definitions are as follows:

-an alkyl group: at C₁-C₂₀In, preferably at C₁-C₁₂Is more preferably at C₁-C₆Is and ideally at C₁-C₄A straight or branched saturated bicarbonate aliphatic group of (a). The term "branched" means that at least one lower alkyl group (such as methyl or ethyl) is carried by a linear alkyl chain. Examples of alkyl groups are methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl and n-pentyl.

-aryl: any functional group or substitution derived from at least one aromatic ring; an aromatic ring corresponds to the entire monocyclic or polycyclic radical scheme comprising a delocalized pi system, wherein each atom of the ring contains an orbital p, the orbitals p being superposed on one another; examples of such aryl groups are: phenyl, biphenyl, naphthalene, and anthracene. The aryl groups of the present invention preferably contain 4 to 12 carbon atoms, and desirably 5 to 6 carbon atoms. Desirably, the aryl groups of the present invention are phenyl groups.

Thus, the electron acceptor compound (B) may be selected from 2, 2-bis- (4-hydroxy-3-methylphenyl) propane (bisphenol C, CAS number: 79-97-0), 4-hexyl-1, 3-dihydroxybenzene (4-hexylresorcinol, CAS number: 136-77-6), 4' -cyclohexylidenebisphenol (BPZ, CAS number: 843-55-0), 4' - (hexafluoroisopropylidene) diphenol (bisphenol AF, CAS number: 1478-61-1), 4' - (1-phenylethylidene) bisphenol (CAS number: 1571-75-1), 2' -dihydroxybiphenyl (CAS number: 1806-29-7), 4' -ethylidenebisphenol (CAS number: 2081-08-5), 4,4'- (1, 4-phenylenediisopropylidene) bisphenol (CAS number: 2167-51-3), 1, 1-bis (4-hydroxy-3-methylphenyl) cyclohexane (CAS number: 2362-14-3), 9-bis (4-hydroxyphenyl) fluorene (CAS number: 3236-71-3), 4' - (1, 3-phenylenediisopropylidene) bisphenol (CAS number: 13595-25-0), 1,1, 1-tris (4-hydroxyphenyl) ethane (CAS number: 27955-94-8), 4'- (2-ethylhexyl) diphenol (CAS number: 74462-02-5), a, a, a' -tris (4-hydroxyphenyl) -1-ethyl-4-isopropylbenzene (CAS number: 110726-28-8), 4- (1,1,3, 3-tetramethylbutyl) phenol (CAS number: 140-66-9), 4-hydroxydiphenyl ether (CAS number: 831-82-3), bis (2-hydroxy-1-naphthyl) methane (CAS number: 1096-84-0), 4- (methylsulfonyl) phenol (CAS number: 14763-60-1), 4-hydroxyphenyl-4-isopropoxyphenylsulfone (CAS number: 95235-30-6), 4' -dihydroxybiphenyl (CAS number: 92-88-6), 4-hydroxybiphenyl (CAS number: 92-69-3), p-hydroxycumene (CAS number: 99-89-8), 2, 4-dihydroxybenzophenone (CAS number: 131-56-6), Hydroquinone monomethyl ether (MEHQ, CAS number: 150-76-5), 3-N-pentadecylphenol (CAS number: 501-24-6), 4- (2-phenylisopropyl) phenol (CAS number: 599-64-4), 5-chloro-2 (2, 4-dichlorophenoxy) phenol (CAS number: 3380-34-5), N- (p-toluenesulfonyl) -N ' - (3- (-p-toluenesulfonyloxy) phenyl) urea (CAS number: 232938-43-1), 2-bis (3, 5-dibromo-4-hydroxyphenyl) propane (CAS number: 79-94-7), 4' -isopropylidenediphenol (CAS number: 80-05-7) and 4,4' -sulfonyldiphenol (BPS, CAS number: 80-09-1).

Preferably, the electron acceptor compound (B) is selected from the group consisting of 2, 2-bis (4-hydroxy-3-methylphenyl) propane (bisphenol C, CAS number: 79-97-0), 4-hexyl-1, 3-dihydroxybenzene (4-hexylresorcinol, CAS number: 136-77-6), 4' -cyclohexylidenebisphenol (BPZ, CAS number: 843-55-0), 4' - (hexafluoroisopropylidene) diphenol (bisphenol AF, CAS number: 1478-61-1), 4' - (1-phenylethylidene) bisphenol (CAS number: 1571-75-1), 2' -dihydroxybiphenyl (CAS number: 1806-29-7), 4' - (1, 4-phenylenediisopropylidene) diphenol (CAS number: 2167-51-3), 1, 1-bis (4-hydroxy-3-methylphenyl) cyclohexane (CAS number: 2362-14-3), 9-bis (4-hydroxyphenyl) fluorene (CAS number: 3236-71-3), 4' - (1, 3-phenylenediisopropylidene) bisphenol (CAS number: 13595-25-0), 1,1, 1-tris (4-hydroxyphenyl) ethane (CAS number: 27955-94-8), 4' - (2-ethylhexylidene) diphenol (CAS number: 74462-02-5), and a, a, a ' -tris (4-hydroxyphenyl) -1-ethyl-4-isopropylbenzene (CAS number: 110726-28-8).

The thermochromic pigment compositions of the present invention are prepared by: dissolving the compounds (A) and (B) in the compound (C) of the formula (I) of the present invention; and then stirred using a mixer (e.g., a homogenizer or a disperser) until a homogeneous mixture is obtained.

Therefore, the compounds (A) and (B) related to the compound of formula (I) of the present invention can be made into microcapsules. Thus, the thermochromic pigment compositions of the present invention are encapsulated in microcapsules to form thermochromic pigment microcapsules. Such thermochromic pigment microcapsules have another object according to the present invention. The microcapsules are advantageously characterized by being resistant to mechanical constraints, by being insoluble in water and therefore dispersible in water, and by a slow rate of agglomeration.

The condensation temperature (decolorization temperature T4) of the thermochromic pigment microcapsules of the present invention can vary from 20 ℃ to 80 ℃, preferably from 30 ℃ to 80 ℃ and ideally from 40 ℃ to 70 ℃.

The crystallization temperature (or re-coloration temperature T1) of the thermochromic pigment microcapsules of the present invention may vary from-40 ℃ to 20 ℃, preferably from-30 ℃ to 10 ℃ and ideally from-20 ℃ to 0 ℃.

The thermochromic pigment microcapsules of the present invention have an average diameter in the range of 0.5 μm to 30 μm, preferably 1 μm to 10 μm and ideally 3 μm to 5 μm. This average diameter corresponds to d90 in volume and means that 90% of the volume of the microcapsules consists of microcapsules of a size within the indicated interval. The average diameter can be determined by laser granulometry using a Zetasizer Nano ZS device from malvern instruments (malvern instruments).

The microencapsulation procedure used includes, but is not limited to, conventional methods such as:

chemical procedures relying on the in situ formation of coated microcapsules, such as by polymerization or interfacial polycondensation, which are preferred procedures;

physicochemical procedures, for example by phase separation or coacervation, by solvent evaporation-extraction or by hot melting;

mechanical procedures, such as those by spray drying, droplet melting or freezing or spraying.

The thermochromic pigment microcapsules of the present invention are advantageously based on amino resins, and preferably on melamine resins, urea resins or benzoguanamine resins.

The thermochromic pigment microcapsules of the present invention are preferably prepared from melamine resins by in-situ polymerization.

Another object of the present invention relates to an ink composition containing thermochromic pigment microcapsules according to the present invention.

The thermochromic pigment microcapsules of the present invention present in the ink composition comprise 5 to 50% by weight of the total weight of the ink composition.

Further, the ink composition of the present invention is mainly composed of water. Advantageously, the water represents from 40% to 80% by weight of the total weight of the ink composition.

The ink compositions of the present invention may also contain one or more water-miscible co-solvents. Thus, the ink composition of the present invention may contain an organic or aqueous solution, preferably an aqueous solvent.

Examples of solvents that may be added to the ink composition of the present invention are water and water-miscible polar solvents such as:

-an alcohol: c₁-C₁₅Straight-chain or branched alcohols of (1), such as isopropanol, butanol, isobutanol, pentanol, benzyl alcohol; glycerol; diglycerin; a polyglycerol;

esters, such as ethyl acetate or propyl acetate;

carbonates, such as propylene carbonate or ethylene carbonate,

ketones, such as methyl isobutyl ketone (MIBK), acetone or cyclohexanone;

diols, such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, polyethylene glycol, ethylene glycol monomethyl ether, 3-butanediol and thiodiethylene glycol;

amides, such as dimethylacetamide or dimethylformamide; and

-mixtures thereof.

The solvent is present in an amount of from 5 wt% to 20 wt% based on the total weight of the ink composition.

The ink compositions of the present invention may also contain one or more specific adjuvants, which may function differently based on the end intended use. These uses may relate to printing inks for serigraphy, offset printing, rotogravure, spray coating, electrostatic coating, electrodeposition coating, roller coating, ink jet printing; inks for writing instruments such as ball-point pens, ink pens, markers and colored pencils. The ink composition of the present invention may also be added to a thermoplastic resin composition or a thermosetting composition to make a mold.

Examples of such adjuvants are:

rheology modifiers (rheology agents) capable of generating a gel effect, such as xanthan gum or arabic gum,

defoamers, such as modified aqueous silicone dispersions (Synthron)

)，

pH regulators, such as sodium hydroxide, triethanolamine,

surfactants, e.g. polyether polyols (TERGITOL from Dow chemical Co., Ltd. (DOW))^TM)，

Biocides, e.g. isothiazolinones (of the Thor company))，

Preservatives, such as benzotriazoles,

-a lubricant, which is a lubricant,

-a dispersing agent,

-a coalescing agent,

-a cross-linking agent,

-a wetting agent,

-a plasticizer which is capable of forming a film,

-an antioxidant agent,

-a UV stabilizer.

Another object of the present invention relates to a writing instrument containing the ink composition according to the invention. These tools generally comprise a body containing the ink composition of the invention and eventually an erasing agent. The writing instrument according to the invention is advantageously selected from ballpoint pens, colored pencils, chalks, and ideally from friction-erasable ballpoint pens. The erasing element of the writing instrument is preferably an eraser.

The ink composition can be applied to paper, fiber, leather, plastic, glass, metal, wood, concrete.

In addition to the above clauses, the present invention also encompasses other clauses resulting from the additional description below that pertains to the synthesis of compound (I) of formula (la), the characterization of said compound, and the use of said compound as a temperature change modifier in thermochromic pigment compositions according to the present invention.

Example (c):

compounds (1), (2) and (3) of the following formulae:

prepared according to the following scheme:

synthesis of Compound (1):

15.93-pentadecylphenol (CAS number: 501-24-6) and 5.8g triethylamine (CAS number: 121-44-8) were dissolved in 250mL tetrahydrofuran (CAS number: 109-99-9). The reaction environment was kept at room temperature and made inert by the addition of nitrogen. Decanoyl chloride (CAS number: 112-13-0), 10g, was added dropwise over 15 minutes. After this addition, the reaction environment was stirred at room temperature for 30 minutes.

The reaction environment was then extracted with 100mL ethyl acetate. The organic phase was recovered and washed three times with 150mL of water. The organic phase was then dried over sodium sulfate and the solvent was evaporated.

The product was recrystallized twice from ethanol. Gas chromatography (GPC) analysis of the product obtained indicated a product purity of 98%.

Synthesis of Compound (2):

11.1g of 3-pentadecylphenol (CAS number: 501-24-6) and 4.0g of triethylamine (CAS number: 121-44-8) were dissolved in 150mL of tetrahydrofuran (CAS number: 109-99-9).

The reaction environment was kept at room temperature and made inert by the addition of nitrogen. 10g of palmitoyl chloride (CAS number: 112-67-4) was added dropwise over 15 minutes. At the end of the addition, the reaction environment was stirred at room temperature for 30 minutes.

The reaction environment was then extracted with 100mL ethyl acetate. The organic phase was recovered and washed three times with 150mL of water. The organic phase was then dried over sodium sulfate and the solvent was evaporated.

The product was recrystallized once from ethanol and once from isopropanol. Gas chromatography (GPC) analysis of the product obtained indicated a product purity of 94%.

Synthesis of Compound (3):

10.0g of 3-pentadecylphenol (CAS number: 501-24-6) and 3.7g of triethylamine (CAS number: 121-44-8) were dissolved in 150mL of tetrahydrofuran (CAS number: 109-99-9). The reaction environment was kept at 5 ℃ and made inert by addition of nitrogen. 10g of stearoyl chloride (CAS number: 112-76-5) was added dropwise over 15 minutes. At the end of the addition, the reaction environment was stirred at room temperature for 30 minutes.

The reaction environment was then extracted with 100mL ethyl acetate. The organic phase was recovered and washed three times with 150mL of water. The organic phase was then dried over sodium sulfate and the solvent was evaporated.

The product was recrystallized twice from ethanol. Gas chromatography (GPC) analysis of the product obtained indicated a product purity of 98%.

The condensation temperatures T of the compounds (1), (2) and (3) obtained are measured by Differential Scanning Calorimetry (DSC) using a TA Instruments Q20 apparatus in the temperature range-50 ℃ to 100 ℃ at a heating/cooling rate of +/-20 ℃ per minute_FUS. Measured byThe temperatures are shown in table 1 below.

Table 1:

a compound of formula (I)	TFUS(℃)
		Compound (1)	30
Compound (2)	47
		Compound (3)	48

Preparation of thermochromic pigment compositions:

a thermochromic pigment composition was prepared by mixing 2.2 parts by weight of 3- (4-diethylamino-2-ethoxyphenyl) -3- (1-ethyl-2-methylindol-3-yl) -4-azaphthalide (compound (A), CAS No.: 69898-40-4), 2.2 parts by weight of 4,4' - (hexafluoroisopropylidene) diphenol (compound (B1), CAS No.: 1478-61-1), 2.2 parts by weight of 2, 2-bis (4-hydroxy-3-methylphenyl) propane (compound (B2), CAS No.: 79-97-0), and 93.4 parts by weight of previously prepared compound (3) (compound (C)).

The resulting mixture was heated and stirred at a temperature of 110 ℃ for 45 minutes until the compounds (A), (B1) and (B2) were completely dissolved in the compound (C).

Preparation of thermochromic pigment microcapsules:

with 8.4 parts by weight ofAn aqueous solution of sodium hydroxide (1.0M solution) was neutralized with 7.2 parts by weight of an aqueous solution of a maleic anhydride copolymer and methyl vinyl ether (33% by weight of copolymer solution). Diluting the solution with 42.0 parts by weight of water and homogenizing at least 15m.s^-1The speed of (a) emulsify the mixture. 26.0 parts by weight of the previously prepared thermochromic pigment composition were added and the resulting emulsion now had a temperature of 85 ℃ for 30 minutes. Then 16.4 parts by weight of the prepolymer melamine-formaldehyde (prepolymer in 50% by weight aqueous solution) was added dropwise to the mixture. The reaction environment is then heated to 90 ℃ and at least 15m.s^-1Mixed for 4 hours.

A slurry of thermochromic pigment microcapsules dispersed in an aqueous solvent was obtained, the microcapsules having a diameter d90 of 4.6 μm, as determined with the malvern instruments Zetasizer Nano ZS system under 632nm irradiation.

The obtained thermochromic pigment microcapsule changes from blue to colorless at a temperature of above 48 ℃, and has a color hysteresis effect.

Table 2: transition temperature of the prepared thermochromic pigment microcapsules

The measured transition temperatures were as follows:

t1: complete re-coloring temperature

T2: temperature of partial recolouration

T3: partial decolorization temperature

T4: total decolorization temperature

Δ H hysteresis range T_G–T_H。