WO2016154782A1

WO2016154782A1 - Squarylium compounds used for lcd color filters

Info

Publication number: WO2016154782A1
Application number: PCT/CN2015/075191
Authority: WO
Inventors: Xiaolian HU; Yang Li; Guihong LIAO; Kainan ZHANG; Matthew REMY; Chao He; Hua Ren; Andong Liu; Zhi Xu; Cassie FHANER; Yiyong He; Elisabeth SWENSON
Original assignee: Dow Global Technologies Llc
Priority date: 2015-03-27
Filing date: 2015-03-27
Publication date: 2016-10-06
Also published as: TW201700484A

Abstract

Squarylium compounds suitable for forming color filters used for a liquid crystal display device, a method for synthesis of the squarylium compounds, a composition containing a resin and the squarylium compounds, an article having a polymer layer containing the compounds and a resin, and color filters containing the compounds are provided.

Description

SQUARYLIUM COMPOUNDS USED FOR LCD COLOR FILTERS

Field of the invention

The present invention relates to squarylium compounds and a mixture thereof suitable for forming color filters used for a liquid crystal display device, a method for synthesis of the squarylium compounds, a composition containing a resin and the squarylium compounds, an article having a polymer layer formed from the composition, and color filters comprising the squarylium compounds.

Background of the invention

Liquid crystal display (LCD) devices currently dominate the display market because of their excellent display characteristics such as energy efficiency, color purity, and/or slimness. As a key component of LCD devices, translucent color filters play the critical role of generating Red/Green/Blue lights by filtering white light from a back sheet. This capacity originates from the Red/Green/Blue colorants comprised in color filter units. Each colorant possesses a characteristic absorbance spectrum and shows one of the three primary colors when illuminated with white visible light-wavelength ranges from 380 nm to 780 nm. The controlled mixing of primary colors from each color filter unit produced by colorants will generate the final color of pixels. So the efficiency of color filters directly impacts LCD’s performance.

Pigments and dyes are two primary types of colorants. Pigments have good stability against heat, light and chemicals. Due to their intrinsic insolubility, pigments must be ground into micro/nano particles before being added into a color resist to make a color filter. The agglomerated particle of a colorant causes light scattering. As a result, light signals are lost and transmittance is low, and more light energy must be applied to provide enough brightness for the LCD.

In contrast to pigments, dyes are soluble in many materials so that they are dispersed at the molecular level. If dyes instead of pigments are used in color filters, light scattering will be significantly reduced. Dye-based color filters could have higher transmittance, and energy cost could thus be greatly reduced. However, dye’s stability against light, heat and chemical resistance is generally inferior to pigments. As a result, commercialized LCD color filters are at present predominantly pigments plus a few pigment-dye hybrids.

Squarylium compounds are a colorant with good thermal stability. Some squarylium compounds are used for LCD color filters, see e.g. WO2013/094827A, WO2013/047859A, WO2013/047860A, JP2012168258A, JP2006079011A, JP2006079012A, WO2008/035554A, JP2008275726A, JP2009040860A, US2007212622A, JP2012013945A, JP2004238606A and JP2004258514A, but those compounds generally have insufficient solubility in common organic solvents for color filters.

Accordingly, squarylium compounds which are both stable and have satisfactory solubility in organic solvents are still desired.

Summary of the invention

Inventors of this invention have found new squarylium compounds having a siloxane or silyl ether side chains which are stable and have good solubility in an organic solvent used for color filters. Inventors of this invention have further found that (1) asymmetric squarylium compounds having a siloxane or silyl ether side chain show improved compatibility with acrylate resin normally used in color filters and also show deeper blue color than symmetric squarylium compounds； and (2) crosslinkable groups such as acrylate or epoxy groups on the side chain improve the compatibility with acrylate resin.

Therefore, one aspect of this invention relates to a squarylium compound which has siloxane or silyl ether structure and is represented by the general formula (1) :

wherein R₁ to R₆ are selected from the group consisting of hydrogen, hydroxyl, amide, amine, silyl, alkylsulfanyl, substituted or non-substituted alkoxy having 1 to 20 carbon atoms and substituted or non-substituted alkyl having 1 to 20 carbon atoms, substituent of the alkoxy or the alkyl is –OCOR₂₈ wherein R₂₈ is saturated or unsaturated hydrocarbon, at least one of R₁ to R₃ and at least one of R₄ to R₆ are amines represented by NR₇R₈, wherein R₇ and R₈ are selected from the group consisting of substituted or non-substituted alkyl having 1 to 20 carbon atoms, alkenyl, aryl, heteroaryl, hydrogen, formyl, and –L-S1, substituent of the alkyl is –OCOR₂₈, L is a divalent linking group selected from direct bond, oxygen atom and saturated or unsaturated hydrocarbon having 1 to 20 carbon atoms which may contain hetero atoms, S1 is siloxane or silyl ether containing group represented by the following formula (3) to (5) :

wherein R₉ to R₁₁, R₁₃ to R₁₆, R₁₈ to R₂₃ and R₂₅ to R₂₇ are alkyl having 1 to 20 carbon atoms, n and m are integer from 0 to 10, R₁₂, R₁₇ and R₂₄ are alkyl having 1 to 20 carbon atoms or G, G is a crosslinkable group having at least one of epoxy, acrylate, acrylamide, and ethylenically unsaturated group, *means the position which bonds to L and at least one of R₇ to R₈ is –L-S1.

Another aspect of this invention relates to a method for synthesis of the squarylium compound disclosed above, comprising the step of contacting a squarylium compound having ethylenically unsaturated group with siloxane or silyl ether compound having hydrogen atom.

Still other aspects of this invention relate to a composition comprising resin and the squarylium compound； an article having a polymer layer formed from the composition disclosed above； and a color filter comprising at least one of the squarylium compound.

Another and further aspect of this invention relates to a squarylium compound mixture obtained from the steps of: (a) contacting5- (diallylamino) benzene-1, 3-diol with squaric acid to obtain reaction product A, and (b) contacting the reaction product A with siloxane or silyl ether compound having hydrogen atom under the presence of a catalyst.

Brief description of the drawings

Fig. 1 is a HPLC chart of a mixture of squarylium compounds (mixture B) obtained by Example 1.

Fig. 2 is a NMR spectrum of a squarylium mixture (Compound 8) obtained by Example 3.

Fig. 3a and 3b are photographs showing color films formed from squarylium compounds and acrylate resin.

Detailed description of the invention

As used throughout this specification, the abbreviations given below have the following meanings, unless the context clearly indicates otherwise: g ＝gram (s) ； mg ＝ milligram (s) ； mm ＝ millimeter (s) ； min. ＝ minute (s) ； s ＝ second (s) ； hr. ＝hour (s) ； rpm ＝ revolution per minute； ℃ ＝ degree (s) Centigrade. Throughout this specification, “ (meth) acrylic” is used to indicate that either “acrylic” or “methacrylic” functionality may be present. As used throughout this specification, the words “resin” and “polymer” are used interchangeably. The words “alkaline soluble resin” and “binder” are used interchangeably.

Squarylium compound

The present invention provides squarylium compounds represented by the general formula (1) .

In the formula (1) , R₁ to R₆ are independently selected from the group consisting of hydrogen, hydroxyl, amide, amine, silyl, alkylsulfanyl, substituted or non-substituted alkoxy having 1 to 20 carbon atoms, and substituted or non-substituted alkyl having 1 to 20 carbon atoms. Substituent of the alkoxy or the alkyl is –OCOR₂₈. R₂₈ is a saturated or unsaturated hydrocarbon.

The alkyl group has at least 1 carbon atom, and has less than 20 carbon atoms, preferably less than 8 carbon atoms. Examples of the alkyl group are； methyl, ethyl, propyl, butyl, hexyl, octyl, decyl, dodecyl, hexadecyl, octadecyl, isopropyl, sec-propyl, sec-butyl, tert-butyl, 2-ethylhexyl, cyclohexyl, 1-norbornyl and 1-adamantyl.

The alkoxy group has at least 1 carbon atom, and has less than 20 carbon atoms, preferably less than 8 carbon atoms. Examples of the alkoxy group are； methoxyl, ethoxyl, propoxyl, butoxyl, hexoxyl, octoxyl, sec-butoxyl and tert-butoxyl.

In the formula (1) , at least one of R₁ to R₃ and at least one of R₄ to R₆ are amine represented by the formula (2) . Preferably, R₃ and R₆ are amine represented by the formula (2) .

In the formula (2) , R₇ and R₈ are selected from the group consisting of substituted or non-substituted alkyl having 1 to 20 carbon atoms, alkenyl, aryl, heteroaryl, hydrogen, formyl and –L-S1. At least one of R₇ and R₈ is –L-S1. Substituent of the alkyl is –OCOR₂₈. L is a divalent linking group selected from direct bond, oxygen atom and saturated or unsaturated hydrocarbon having 1 to 20 carbon atoms which may contain hetero atoms. Preferably, L is alkylene having 1 to 5 carbon atoms or

S1 is siloxane or silyl ether containing group represented by the following formulas (3) to (5) .

In the formulas (3) to (5) , *means the position which bonds to L. R₉ to R₁₁, R₁₃ to R₁₆, R₁₈ to R₂₃ and R₂₅ to R₂₇ are alkyl having 1 to 20 carbon atoms. n and m are integer from 0 to 10. Preferably, n is integer less than 4 and m is integer less than 2. R₁₂, R₁₇ and R₂₄ are alkyl having 1 to 20 carbon atoms or G. G is a crosslinkable group having at least one of epoxy, acrylate, acrylamide, and ethylenically unsaturated group. Preferably, G is crosslinkable group having epoxy or acrylate group.

The squarylium compound of the present invention can be used as a mixture. A mixture of two or more of squarylium compound can increase the solubility of compounds in various organic solvents.

The squarylium compound represented by the formula (1) is useful in a color filter of a LCD since the squarylium compound of the invention has excellent thermal stability and high enough solubility for an organic solvent used in the manufacture of LCD such as propylene glycol monomethyl ether acetate (PGMEA) . In addition, the squarylium compound which has asymmetric siloxane, silane/silyl side-chain shows improved transmittance in a color filter. When the compound represented by the formula (1) has G (crosslinkable group) such as acrylate or epoxy groups, the squarylium compound shows improved compatibility with a resin normally used for a color filter.

The squarylium compound of the present invention can be synthesized by the reaction of a siloxane or silyl ether compound having hydrogen atom with a corresponding squarylium compound having ethylenically unsaturated group. In detail, the reaction comprises contacting (A) the compound represented by the following formula (6) with (B) siloxane or silyl ether compound represented by the formulas (7) to (9) under the presence of a catalyst.

In the formula (6) , R₁ to R₆ are selected from the group consisting of hydrogen, hydroxyl, amide, amine, silyl, alkylsulfanyl, substituted or non-substituted alkoxy having 1 to 20 carbon atoms and substituted or non-substituted alkyl having 1 to 20 carbon atoms. Substituent of the alkoxy or the alkyl is –OCOR₂₈, wherein R₂₈ is saturated or unsaturated hydrocarbon. At least one of R₁ to R₃ and at least one of R₄ to R₆ are amine shown as NR₇R₈, wherein R₇ and R₈ are selected from the group consisting of substituted or non-substituted alkyl having 1 to 20 carbon atoms, alkenyl, aryl, heteroaryl, hydrogen, formyl and –L-X. The substituent of the alkyl is –OCOR₂₈. L is a divalent linking group selected from direct bond, oxygen atom and saturated or unsaturated hydrocarbon having 1 to 20 carbon atoms which may contain hetero atoms. X is a group having ethylenically unsaturated group. At least one of R₇ and R₈ is –L-X.

In the formulas (7) to (9) , R₉ to R₁₁, R₁₃ to R₁₆, R₁₈ to R₂₃ and R₂₅ to R₂₇ are alkyl having 1 to 20 carbon atoms. n and m are integer from 0 to 10. R₁₂, R₁₇ and R₂₄ are alkyl having 1 to 20 carbon atoms or G. G is a crosslinkable group having at least one of epoxy, acrylate, acrylamide, and ethylenically unsaturated group.

When at least one of R₁₂, R₁₇ and R₂₄ is G, the siloxane compounds disclosed below can be used.

(CAS Registry Number: 17980-29-9)

(CAS Registry Number: 623932-34-3)

(CAS Registry Number: 140404-94-0)

(CAS Registry Number: 96474-12-3)

These compounds are commercially available or can be synthesized.

The catalyst is preferably hydrosilylation catalyst (Pt, Pd, Rh or Ru catalyst) . Examples of the catalyst include Karstedt’s catalyst (organoplatinum compound with molecular formula of C₂₄H₅₄O₃Pt₂Si₆) , chloroplatinic acid and Wilkinson’s catalyst. Karstedt’s catalyst is preferable as a catalyst of the invention. The amount of the catalyst is basically 10 to 1000 ppm (as a mole) , preferably 40-200ppm.

The molar ratio of the compound represented by the formula (6) and the compound represented by the formula (7) , formula (8) or formula (9) depends on the number of ethylenically unsaturated group of the formula (6) compound. When the compound represented by the formula (6) has four ethylenically unsaturated groups, the molar ratio of the compound represented by the formula (6) and the compound represented by the formula (7) , (8) or (9) is basically 1: 1 to 1: 20, preferably 1: 2 to 1: 10, more preferably 1: 2 to 1: 6.

The reaction is conducted in a solvent. Any known solvent can be used unless the solvent does not react with the components used in the reaction. Examples of solvents include n-butanol, N-methylpyrrolidone (NMP) , N, N-Dimethylmethanamide (DMF) , Tetrahydrofuran (THF) , Dimethyl sulfoxide (DMSO) , isopropanol, pentanol, dioxane, hexanol and mixture thereof.

The reaction temperature is preferably 20 ℃ or more, more preferably 50 ℃ or more. The reaction temperature is preferably 200 ℃ or less, more preferably 180 ℃ or less. The reaction time is preferably 3 hours or more, more preferably 8 hours or more. The reaction time is preferably 48 hours or less, more preferably 24 hours or less. The obtained product can be separated by recrystallization or column chromatography.

The compound represented by the formula (6) is synthesized by the reaction of substituted or unsubstituted hydroxybenzene, diallylamine and squaric acid. An example of the reaction is shown below.

During the above reaction, three isomers (isomer A, isomer B and isomer C) can be formed. Those isomers can be separated by recrystallization or column chromatography, or can be used as a mixture. In this application, the mixture is also called as “reaction product A. ” The molar ratio between isomer A, isomer B and isomer C varies with reaction conditions such as solvent or temperature. Normally, the molar ratio before purification step (recrystallization) is isomer A : isomer B : isomer C ＝ 1 : 0.15 -0.40 : 0.01 -0.04.

When the reaction product A is contacted with siloxane or silyl ether compound represented by the formulas (7) to (9) disclosed above under the presence of a catalyst, the obtained squarylium compounds mixture may contain the following three compounds.

In the formulas (10) to (12) , S1 is siloxane or silyl ether containing group. Those siloxane or silyl ether containing group correspond to the siloxane or silyl ether containing group represented by the formulas (3) to (5) disclosed above. In addition, the squarylium compounds mixture may comprise isomers for a structure with one unreacted ethylenically unsaturated bond.

Composition

The composition of the present invention comprises compounds of formula (1) and a resin. The resin is preferably alkaline soluble resin. The composition preferably additionally comprises a cross-linker (cross-linking agent) , a solvent and a radiation-sensitive compound such as a photo initiator. The composition can form a film useful for a color filter.

The content of compounds of formula (1) in the composition of the present invention varies depending on each molar absorption coefficient and required spectral characteristics, film thickness, or the like, but it is preferably at least 1 wt％, more preferably at least 2 wt％, the most preferably at least 5 wt％based on the total solid contents of the composition. The preferable content is less than 55 wt％, more preferably less than 45 wt％, most preferably less than 35 wt％based on the total solid contents of the composition.

The composition of the present invention can comprises other coloring materials in addition to the composition as recited in formula (1) . Normally the use of additional coloring material is determined from the required spectral characteristics of a material to be formed from the composition.

The alkaline soluble resin is also known as “binder” in this technical art. Preferably, the alkaline soluble resin is dissolved in an organic solvent. The alkaline soluble resin can be developed with an alkaline solution such as tetramethyl ammonium hydroxide (TMAH) aqueous solution after forming a film.

The alkaline soluble resin (binder) is normally a linear organic polymer. The binder optionally has a crosslinkable group within the polymer structure. When the composition of the present invention is used as a negative type photosensitive composition, such crosslinkable group can react and form crosslink by exposure or heating so that the binder becomes a polymer which is insoluble in alkaline.

Many kinds of binder are known in this art. Examples of such binder are (meth) acrylic resin, acrylamide resin, styrenic resin, epoxy resin, polysiloxane resin, phenolic resin, novolak resin, and co-polymer or mixture of those resins. In this application, (meth) acrylic resin (polymer) includes copolymer of (meth) acrylic acid or ester thereof and one or more of other polymerizable monomers. For example, acrylic resin can be polymerized from acrylic acid and/or acrylic ester and any other polymerizable monomers such as styrene, substituted styrene, maleic acid or glycidyl (meth) acrylate.

The binder preferably has at least 1,000 of weight-average molecular weight (Mw) , more preferably at least 2,000 of Mw measured by a GPC method using polystyrene as a standard. At the same time, the binder preferably has less than 200,000 of Mw, more preferably less than 100,000 of Mw measured by the same method described above.

The amount of the binder used in the composition of the present invention is preferably at least 10 wt％, more preferably at least 20 wt％based on the total solid contents of the composition. At the same time, the preferable amount of the binder is less than 80 wt％, more preferably less than 50 wt％, the most preferably less than 30 wt％based on the total solid contents of the composition.

The composition of this invention optionally further comprises a cross-linking agent to obtain a further hardened material. It is also known as a radical-polymerizable monomer. When the composition of this invention is used as a negative type photosensitive composition, such cross-linking agent can form a crosslink by exposure or heating and contribute to get a further hardened material. Well known cross-linking agent can be used for the composition of this invention. Examples of cross-linking agents are epoxy resin such as bisphenol A diglycidyl ether, ethyleneglycol diglycidyl ether, butanediol diglycidyl ether, diphentaerythritol pentaglycidyl ether or dipentaerythritol hexaglycidyl ether and substituted nitrogen containing compound such as melamine, urea, guanamine or glycol uril.

The composition of this invention optionally further comprises a solvent. The solvent to be used for the composition is not limited, but preferably selected from based on the solubility of components of the composition such as binder or squarylium dye. Examples of the preferable solvent include esters such as ethylacetate, n-butyl acetate, amyl formate, butyl propionate or 3-ethoxypropionate, ethers such as diethylene glycol dimethyl ether, ethylene glycol monomethyl ether or propylene glycol ethyl ether acetate and ketones such as methylethylketone, cyclohexanone or 2-heptanone. Propylene glycol monomethyl ether acetate (PGMEA) is a preferable solvent.

When the composition of this invention is a negative type radiation-sensitive composition, the composition preferably comprises a photo initiator. Photo initiator also called as photopolymerization initiator and including radical initiator, cationic initiator and anionic initiator. Examples of a photo initiator include； oxime ester type initiator, sulfonium salts initiator, iodide salts initiator and sulfonate initiator.

The composition of this invention can comprise other radiation-sensitive compound such as a radiation sensitive resin or a photo acid generator.

Polymer layer

The composition of the present invention described above can form a polymer layer on an article. The polymer layer is also described as “polymer film” in the specification.

The contents of the compound as recited in formula (1) in the polymer layer depend on the required color of the film, but at least 1 wt ％, preferably at least 5 wt ％based on the polymer layer. At the same time, the content of the compounds is less than 50 wt ％, preferably less than 35 wt ％based on the polymer layer. The polymer layer also comprises an alkaline soluble resin which is disclosed above.

The polymer layer optionally comprises a photo initiator, a photo acid generator, a radiation sensitive resin and a crosslink agent disclosed above.

The method of forming the polymer layer on an article comprises the steps of； mixing the squarylium compound of this invention with a resin and solvent, coating the mixture on an article which supports a layer and heating the article to form a polymer layer (film) . Optionally, the method comprises one or more of steps of exposing a layer (film) or curing a layer to form crosslinked stable layer.

The resin and the solvent used to the method for forming the polymer layer are same as the one disclosed above.

Examples of an article which supports a layer (film) are glass, metal, silicon substrate and metal oxide coated material.

Any coating method can be used for the coating step, such as rotation coating, cast coating or roll coating.

The thickness of the layer (film) varies depending on the required properties of the film. The thickness of the layer is 0.1 to 5 micron, preferably 0.5 to 3 micron.

The layer (film) has high transmittance and thermal stability from the properties of the squarylium compound of this invention. The squarylium compound can be dissolved in an organic solvent, and has high thermal stability. Therefore the dye does not prevent the transmittance of a film and does not decrease the thermal stability of the film. Such property is important for a color filter of LCD. Therefore, the layer (film) of the present invention is useful as a color filter of LCD.

Color filters

The color filer of this invention comprises the compound as recited in formula (1) . The layer (film) disclosed above can be used for the color filter. Normally, a color filter has multiple units which made from colored films comprising Red/Green/Blue colorants.

The contents of the squarylium compound of this invention in a colored film for a color filter is same as the film disclosed above, at least 1 wt ％, more preferably at least 5 wt ％based on the total weight of the colored film. At the same time, the content is less than 50 wt ％, preferably less than 35 wt ％based on the total weight of the colored film.

A film used for a color filter can be formed by the following steps； coating a solution comprising the compound as recited in formula (1) , binder, a photo initiator and solvent to form a radiation sensitive composition layer on a material, exposing the layer through a patterned mask, and developing the layer with an alkaline solution. Moreover, a curing step of further heating and /or exposing the layer after developing step may be conducted as needed.

Since a color filter comprises three colored films which comprise R/G/B colorant, the steps of forming each colored film are repeated, then a color filter having such three colored films are obtained.

EXAMPLES

Example 1

A mixture of squarylium compounds was prepared.

a. Preparation of tetra allyl squarylium compounds (Allyl-SQs)

Under dry nitrogen atmosphere, a mixture of 1, 3, 5-trihydroxybenzene (11.88 g, 94.2 mmol) , diallylamine (18.27 g, 188.4 mmol) , n-butanol (75 mL) , and toluene (225 mL) was refluxed for 6 h with azeotropic distillation of water. The yellow solution was then cooled, and the solvents including excess diallylamine were evaporated under reduced pressure to give a yellow viscous liquid. Then, a mixture of all above 5- (diallylamino) benzene-1, 3-diol, squaric acid (5.0 g, 43.8 mmol) , n-butanol (90 mL) , and toluene (270 mL) were stirred under dry nitrogen atmosphere and refluxed for 6 h with azeotropic distillation of water. After cooling, a green precipitate was filtered and washed with isopropanol and methanol, affording 13.7g crystalline reaction product A-1. Yield: 63％. ¹H NMR (CDCl₃, ppm) : 11.00 (s, 4H) , 5.83 (s, 4H) , 5.81 (ddt, 4H) , 5.25 (dd, 4H) , 5.16 (dd, 4H) , 3.99 (d, 8H)

b. Hydrosilylation

The above recrystallized sample (Allyl-SQ, 8g, 16.3 mmol) was dissolved in anhydrous THF (480 mL) under dry nitrogen atmosphere. Four equivalents of 1, 1, 1, 3, 5, 5, 5-Heptamethyltrisiloxane (4.00 equiv, 14.5g) was injected through a septum, followed by the addition of Karstedt’s catalyst (platinum divinyltetramethy-siloxanecomplex in xylene, 3wt％, 0.75mL) . The resulting mixture was stirred at 70℃ overnight. After that, a solvent exchange of tetrahydrofuran for ethanol was conducted (68 –70 ℃, 1 atm) , followed by concentration of the solution (ethanol content was 70 g) . The solution was cooled to room temperature by convection over 4 hours and left to stir overnight. The resulting precipitate was filtered through a course glass fritted funnel. The collected solids were washed with cold ethanol (80 g) and dried under vacuum at 40 ℃ to obtain a mixture of squarylium compounds (mixture A) (7.57 g, 33 ％yield) . 1H NMR (CDCl₃, ppm) : 10.96 (s, 4H) , 5.78 (s, 4H) , 3.36 (t, 8H) , 1.55-1.72 (m, 8H) , 0.45 (t, 8H) , 0-0.06 (m, 84H) .

ESI-MS (m/z, Ion, Formula) : 1378, (M+H) ⁺, C₅₆H₁₁₅N₂O₁₄Si₁₂, (theoretical mass 1377) .

The analytical data shows the mixture of squarylium compounds (mixture A) contains the following

Compounds

1a, 1b, 2, 3 and 4 disclosed below.

The same hydrosilylation step was conducted for the reaction product A-1 without recrystallization. A mixture of squarylium compounds was obtained (mixture B) . Mixture A and mixture B contained squarylium compounds as shown in Table 1. The molar ratios between the squarylium compounds were calculated from ratios of HPLC area. HPLC chart for mixture B is shown in Fig. 2.

Table 1

Example 2

A squarylium compound disclosed below was synthesized.

(Compound 7)

a. Preparation of unsymmetrically substituted squaraine (AsySQA)

A dried flask with a magnetic stirring bar was charged with 3- [4- (N, N-dibutylamino) phenyl] -4-hydroxy-cyclobutene-1, 2-dione (1.50 g, 4.98 mmol) , 5- (diallylamino) -1, 3-dihydroxylbenzene (1.02 g, 4.98 mmol) , toluene (50 mL) , and n-butanol (50 mL) under nitrogen. The reaction mixture was stirred at reflux for 34 h and then cooled to ambient temperature. The blue crystal was obtained by filtration and dried (yield 41％) . More products were obtained by further purification. The solvent in the filtrate was removed under reduced pressure and the residue was purified by column chromatography on silica gel eluting with methanol/dichloromethane (Total yield 62％) . ¹H NMR (CDCl₃, ppm) : 12.75 (s, 2H) , 8.07 (d, 2H) , 6.67 (d, 2H) , 5.76-5.88 (m, 4H) , 5.21 (q, 4H) , 4.00 (d, 4H) , 3.40 (t, 4H) , 1.63 (t, 4H) , 1.37 (m, 4H) , 0.98 (t, 6H) . ESI-MS (m/z, Ion, Formula) : 489.2771 (M+H) ⁺, C₃₀H₃₇N₂O₄, (theoretical mass 488.62) .

b. Hydrosilylation

AsySQA (0.50 g, 1.02 mmol) was dissolved in 20 mL anhydrous THF under N₂. 1, 1, 1, 3, 3-Pentamethyldisiloxane (2.20 equiv. , 0.33 g) was injected through a septum, followed by the addition of one drop of Karstedt’s catalyst (platinum divinyltetramethy-siloxane complex in xylene, 3wt) . The resulting mixture was stirred at 50℃ overnight. The solution was evaporated under reduced pressure. The crude product was purified by chromatography on silica. ¹H NMR (CDCl₃, ppm) : 12.68 (s, 2H) , 7.97 (d, 2H) , 6.60 (d, 2H) , 5.70 (s, 2H) , 3.29 (m, 8H) , 0.90 (t, 6H) , 1.55 (m, 4H) , 1.30 (m, 4H) , 0.80 (t, 4H) , 0.43 (t, 4H) , 0.01-0.04 (m, 30H) . ESI-MS (m/z, Ion, Formula) : 785.422, (M+H) ⁺, C₄₀H₆₉N₂O₆ Si₄, (theoretical mass 784.42) .

Example 3 A squarylium mixture disclosed below was synthesized.

a. Preparation of methyl methacrylate modified squarylium (SQ-MMA)

SQ-OH

(2, 4-bis (4- (bis (2-hydroxyethyl) amino) -2, 6-dihydroxyphenyl) -3-oxocyclobut-1-enolate, 100 mg, 0.198 mmol) , 4-dimethylaminopyridine (DMAP, 0.158 mmol, 19.3 mg, 0.8 equiv. ) , triethylamine (Et₃N, 0.832 mmol, 84 mg, 0.12 mL, 4.2 equiv) and dimethylacetamide (DMAc, 3 mL) were added into a three neck round bottom flask. Methacrylic anhydride (MMA, 0.99 mmol, 152 mg, 0.15 mL, 5 equiv. ) in DMAc (0.2 mL) were added into the reaction mixture dropwise via a disposable syringe at 0 ℃. The reaction was monitored by TLC (by 2/1 EtOAc /petroleum ether) . After 6 h, water (200 mL) was added to dilute the whole reaction mixture. Then saturated NaHCO3 (50 mL) was added to promote separation for further extraction step. The crude mixture was extracted by ethyl acetate. The organic phase was combined and then concentrated under reduced pressure. After the solvent was removed, the mixture shows multiple spots on TLC (by 3/2 ethyl acetate/petroleum ether) . All the fractions were collected by flash column chromatography. The mixture SQ-MMA contains tetra, tri and di-substituted MMA SQ. The crude NMR image was shown in Fig. 2.

b. Hydrosilylation

A mixture of SQ-MMA (70 mg) was dissolved in dry toluene (10 mL) in a three neck round bottom flask equipped with a refluxing condenser under N₂. Then, pentamethyldisiloxane (30 μL, 23 mg, 0.16 mmol) , and Karstedt’s catalyst (platinum divinyltetramethy-siloxanecomplex in xylene, 3 wt％, 20 μL, 1.3μmol) were added into the reaction mixture. The reaction mixture was stirred at 75 ℃ for 15 h and then cooled down to room temperature. The solvent was removed under reduced pressure. The crude mixture was then purified a short silica column chromatography via petroleum ether to remove toluene and xylene residue followed by ethyl acetate to collect the product mixture compound 8. The final TLC shows the reaction does occur. The conversion is about 10-20％based upon rough TLC estimation. The final product is a mixture of SQ-MMA and compound 5 which can be confirmed by LC-MS. ESI-MS (m/z, Ion) : 777.28 and 925.33 (M+H) ⁺, theoretical mass and chemical formula were shown below.

The solubility of the mixture in PGMEA was 2.8 wt％.

Example 4 (comparative example)

A compound disclosed below was used in Example 4.

a. Synthesis of Compound 9 (Isobutyl-SQ)

Under dry nitrogen atmosphere, a mixture of 1, 3, 5-trihydroxybenzene (3.96 g, 31.4 mmol) , diisobutyl-amine (8.11 g, 62.8 mmol) , n-butanol (25 mL) , and toluene (75 mL) was refluxed for 6 h with azeotropic distillation of water. The pale-brown solution was then cooled, and the solvents including excess diallylamine were evaporated under reduced pressure to give a brown viscous liquid. Then, a mixture of all above 5- (diisobutylamino) benzene-1, 3-diol, squaric acid (1.7 g, 14.9 mmol) , n-butanol (30 mL) , and toluene (90 mL) were stirred under dry nitrogen atmosphere and refluxed for 6 h with azeotropic distillation of water. After cooling, a yellow-green precipitate was filtered and washed with isopropanol and methanol, affording 4.1 g crystalline product. Yield: 50％. ¹H NMR (CDCl₃, ppm) : 10.99 (s, 4H) , 5.83 (s, 4H) , 3.26 (d, 8H) , 2.10-2.20 (m, 4H) , 0.92-0.98 (m, 24H) .

Example 5 (comparative example)

Allyl-SQs synthesized in Example 1 was used in Example 5.

Example 6 (comparative example)

AsySQA synthesized in Example 2 was used in Example 6.

Example 7 (comparative example)

A compound disclosed below was used in Example 7.

(C. I. Pigment Blue 15: 6)

Properties of squarylium compounds and pigment

(a) Solubility (in PGMEA) of squarylium compounds and pigment (at 25℃) , UV-Vis absorption and thermal stability of those compounds were analyzed. UV-Vis was analyzed by (add here instrument/types/producer of UV-Vis analyzer) . Thermal stability was analyzed by H-NMR and LC-MS before and after baking at 230℃ for 1 hour.

Table 2

Referring to Table 2, it can be found that Examples 1 to 3 show significant improvement both thermal stability and solubility in PGMEA compare with Examples 4 to 7.

(b) The color of mixture A and Compound 7 were compared. The mixture A and Compound 7 were dissolved in PGMEA respectively. Compound 7 with blue shifted UV-Vis spectrum shows deeper blue color compared with the mixture A which shows cyan color.

(c) The compatibility of squarylium compounds with acrylate resin was tested. A simple formulation was made by just mixing the solution of Compound 7 or mixture A in PGMEA with acrylate resin respectively. Content of Compound 7 or mixture A was 5 wt％. The solution was spin coated onto a clean glass substrate with 200rpm spin speed. The obtained films were then dried at 90 ℃ under air atmosphere for 100 seconds. Compound 7 shows improved compatibility with acrylate resin compared with mixture A.

(d) Color by CIE value was analyzed. Films comprising Compound 7 were made same as (c) above. A mixture of pigment blue and acrylate resin was used as a comparison. Content of Compound 7 or pigment blue was 5 wt％. The solution was spin coated onto a clean glass substrate with 200, 300, 400 and 500 rpm spin speed respectively. The obtained films were then dried at 90 ℃ under air atmosphere for 100 seconds. The CIE values (xyY values) were measured using MCPD-6000 (otsuka electronics, Japan) and C2 as light source. Film thickness and xyY values are shown in Table 3, and pictures of those films are shown in Fig. 3.

Table 3

Claims

A squarylium compound represented by the following formula (1)

wherein R₁ to R₆ are selected from the group consisting of hydrogen, hydroxyl, amide, amine, silyl, alkylsulfanyl, substituted or non-substituted alkoxy having 1 to 20 carbon atoms and substituted or non-substituted alkyl having 1 to 20 carbon atoms, substituent of the alkoxy or the alkyl is –OCOR₂₈ wherein R₂₈ is saturated or unsaturated hydrocarbon, at least one of R₁ to R₃ and at least one of R₄ to R₆ are amine represented by the following formula (2)

wherein R₇ and R₈ are selected from the group consisting of substituted or non-substituted alkyl having 1 to 20 carbon atoms, alkenyl, aryl, heteroaryl, hydrogen, formyl, and –L-S1, substituent of the alkyl is –OCOR₂₈, L is a divalent linking group selected from direct bond, oxygen atom and saturated or unsaturated hydrocarbon having 1 to 20 carbon atoms which may contain hetero atoms, S1 is siloxane or silyl ether containing group represented by the following formula (3) to (5) ,

wherein R₉ to R₁₁, R₁₃ to R₁₆, R₁₈ to R₂₃ and R₂₅ to R₂₇ are alkyl having 1 to 20 carbon atoms, n and m are integer from 0 to 10, R₁₂, R₁₇ and R₂₄ are alkyl having 1 to 20 carbon atoms or G, G is a crosslinkable group having at least one of epoxy, acrylate, acrylamide, and ethylenically unsaturated group, *means linkage to L, and at least one of R₇ and R₈ is –L-S1.
A squarylium compound of claim 1, wherein R3 and R6 are amine represented by formula (2)

wherein R₇ and R₈ are selected from the group consisting of substituted or non-substituted alkyl having 1 to 20 carbon atoms, alkenyl, aryl, heteroaryl, hydrogen, formyl, and –L-S1, substituent of the alkyl is –OCOR₂₈, L is a divalent linking group selected from direct bond, oxygen atom and saturated or unsaturated hydrocarbon having 1 to 20 carbon atoms which may contain hetero atoms, S1 is siloxane or silyl ether containing group represented by the following formula (3) to (5) ,

wherein R₉ to R₁₁, R₁₃ to R₁₆, R₁₈ to R₂₃ and R₂₅ to R₂₇ are alkyl having 1 to 20 carbon atoms, n and m are integer from 0 to 10, R₁₂, R₁₇ and R₂₄ are alkyl having 1 to 20 carbon atoms or G, G is a crosslinkable group having at least one of epoxy, acrylate, acrylamide, and ethylenically unsaturated group, *means linkage to L, and at least one of R₇ and R₈ is –L-S1.
The squarylium compound of claim 1, wherein R₁₂, R₁₇ and R₂₄ are alkyl having 1 to 20 carbon atoms.
The squarylium compound of claim 1, wherein at least one of R₁₂, R₁₇ and R₂₄ is G.
A method for synthesis of the squarylium compound of claim 1, comprising the step of: contacting the compound represented by the following formula (6) with siloxane or silyl ether compound represented by the formula (7) to (9) under the presence of a catalyst.

wherein R1 to R6 are selected from the group consisting of hydrogen, hydroxyl, amide, amine, silyl, alkylsulfanyl, substituted or non-substituted alkoxy having 1 to 20 carbon atoms and substituted or non-substituted alkyl having 1 to 20 carbon atoms, substituent of the alkoxy or the alkyl is –OCOR₂₈ wherein R₂₈ is saturated or unsaturated hydrocarbon, at least one of R₁ to R₃ and at least one of R₄ to R₆ are amine represented by the following formula (2)

wherein R₇ and R₈ are selected from the group consisting of substituted or non-substituted alkyl having 1 to 20 carbon atoms, alkenyl, aryl, heteroaryl, hydrogen, formyl, and –L-X, substituent of the alkyl is –OCOR₂₈, L is a divalent linking group selected from direct bond, oxygen atom and saturated or unsaturated hydrocarbon having 1 to 20 carbon atoms which may contain hetero atoms, X is a group having ethylenically unsaturated group, and at least one of R₇ and R₈ is –L-X.

wherein R₉ to R₁₁, R₁₃ to R₁₆, R₁₈ to R₂₃ and R₂₅ to R₂₇ are alkyl having 1 to 20 carbon atoms, n and m are integer from 0 to 10, R₁₂, R₁₇ and R₂₄ are alkyl having 1 to 20 carbon atoms or G, G is a crosslinkable group having at least one of epoxy, acrylate, acrylamide, and ethylenically unsaturated group.
The method of claim 5, wherein R₁₂, R₁₇ and R₂₄ are alkyl having 1 to 20 carbon atoms.
The method of claims 5 or 6, wherein the catalyst is an organoplatinum compound.
A composition comprising a resin and the compound of any of claims 1 to 4.
The composition of claim 8, further comprising a radiation-sensitive compound.
An article having a polymer layer formed from the composition of claims 8 or 9.
The article of claim 10, wherein the polymer layer is formed from a negative-type photosensitive composition.
A color filter comprising at least one of the compounds of any of claims 1 to 4.
A squarylium compound mixture obtained from the steps of:

(a) contacting 5- (diallylamino) benzene-1, 3-diol with squaric acid to obtain reaction product A, and

(b) contacting the reaction product A with siloxane or silyl ether compound represented by the formula (7) to (9) under the presence of a catalyst.

wherein R₉ to R₁₁, R₁₃ to R₁₆, R₁₈ to R₂₃ and R₂₅ to R₂₇ are alkyl having 1 to 20 carbon atoms, n and m are integer from 0 to 10, R₁₂, R₁₇ and R₂₄ are alkyl having 1 to 20 carbon atoms or G, G is a crosslinkable group having at least one of epoxy, acrylate, acrylamide, and ethylenically unsaturated group.
The squarylium compound mixture of claim 13, wherein the mixture comprises at least one of the compounds represented by the formula (10) to (12) .

wherein S1 is siloxane or silyl ether containing group.