WO2002014434A1

WO2002014434A1 - Dibenzoflourenone based chromophores

Info

Publication number: WO2002014434A1
Application number: PCT/AU2001/001000
Authority: WO
Inventors: Lachlan Everett Hall; Kia Silverbrook
Original assignee: Silverbrook Research Pty Ltd
Current assignee: Silverbrook Research Pty Ltd
Priority date: 2000-08-14
Filing date: 2001-08-14
Publication date: 2002-02-21
Anticipated expiration: 2003-02-14
Also published as: EP1311396A1; WO2002014435A1; WO2002014437A8; WO2002014075A1; WO2002014438A1; EP1311396A4; WO2002014437A1

Abstract

Infrared dyes which absorb strongly in the near infrared region of the spectrum but poorly in the visible region are described. The claimed compounds are of formula (1), wherein m and n are the number of fused 6-membered rings attached to the central moiety; Q1 and Q2 are fused rings of formula (2) attached at any of the adjoining positions C1 to C4 and C5 to C8 respectively. Q3, X1, X2, Y, and Z are as described in the specification.

Description

DIBENZOFLOURENONE BASED CHROMOPHORES

FIELD OF INVENTION

The present invention relates to compounds that are suitable for use as dyes. In particular, the present invention relates to compounds that are suitable for use as infrared dyes, to compositions containing these compounds, including color light-sensitive material, and to processes for their use as infrared absorbers. The present invention has particular application to infrared printing inks.

CO-PENDING APPLICATIONS

Various methods, systems and apparatus relating to the present invention are disclosed in the following co-pending applications filed by the applicant or assignee of the present invention simultaneously with the present invention:

NPI001, NPI002, NPI003, NPI003A, NPI004

The disclosures of these co-pending applications are incorporated herein by cross-reference. Each application is temporarily identified by its docket number. This will be replaced by the corresponding International Patent Application Number when available.

BACKGROUND

Recently there has been renewed interest in "innovative" or "functional" dyes. One area of interest is that of optical recording technology where gallium aluminium arsenide (GaAlAs) and indium phosphide (InP) diode lasers are widely used as a light source. Since dyes absorbing in the near infrared (near-IR) region (i.e., beyond about 700 nanometers in wavelength and less than about 2000 nanometers in wavelength) are required and the oscillation wavelengths fall in the near-infrared region, they are suitable candidates for use as infrared dyes.

Infrared dyes have applications in many areas. For example, infrared dyes are important in the optical data storage field, particular in the DRAW (Direct Reading After Writing) and WORM (Write Once, Read Many) disk, which is used for recording. Currently, indolinocyanine dyes, triphenylmethane dyes, naphthalocyanine dyes and indonanaphthalo-metal complex dyes are commercially available for use as organic colorants in DRAW disks. Cyanine dyes can only be used if additives improve the lightfastness.

Another application of infrared dyes is in thermal writing displays. In this application, heat is provided by a laser beam or heat impulse current. The most common type of infrared dyes used in this application are the cyanine dyes, which are known as laser dyes for infrared lasing. Infrared dyes are also used as photoreceptors in laser printing. Some infrared-absorbing dyes are used in laser filters. They also find application in infrared photography and even have application in medicine, for example, in photodynamic therapy.

The compounds of the present invention will now be described in the context of printing inks and the like, but it will be understood by the skilled reader that the compounds described hereunder may be used in other applications, for example, those set out above. Fast, error-free data entry is important in current communication technology. Automatic reading of digital information in printed, digital and analog form is particularly important. An example of this technology is the use of printed bar codes that are scannable. In many applications of this technology, the bar codes are printed with an inks that are visible to the unaided eye. There are, however, applications (eg security coding) that require the barcode or other intelligible marking to be printed with an ink that invisible to the unaided eye but which can be detected under UV light or infrared light (E ).

For instance, U.S. Pat. No. 5,093,147 describes a method exploiting the process of fluorescence in which a dye is excited by ultra-violet (UV), visible or near-IR radiation and fluorescent light emitted by the dye material is detected. This reference describes a jet printing process used to apply a compatible liquid or viscous substance containing an organic laser dye that is poorly absorptive of radiation in the visible wavelength range of about 400 run to about 700 nm, and is highly absorptive of radiation in the near-IR wavelength range of about 750 nm to about 900 nm. The dye fluoresces at longer wavelengths in the IR in response to radiation excitation in the near-IR range.

Another example is described in U.S. Pat. No. US Pat No. 5,460,646 (Lazzouni et al) which describes the use of a colorant which is silicon (IV) 2,3-naphthalocyanine bis((Rι)(R₂)(R₃)-silyloxide) wherein Ri, R₂, and R₃ are selected from the group consisting of an alkyl group, at least one aliphatic cyclic ring, and at least one aromatic ring.

The infrared absorbing dyes Squarylium and Croconium dyes have been extensively described in the literature (see for example, T. P. Simard, J. H. Yu, J. M. Zebrowski- Young, N. F. Haley and M. R. Deny, J. Org. Chem. 65 2236 (2000), and J. Fabian, Chem. Rev. 92 1197 (1992)). These prior art compounds have a central squarylium or croconium moiety connected to traditional electron donors. These donors act to donate an electron to the central squarylium or croconium moieties. However, these particular dyes do not absorb at a high enough wavelength and/or also absorb too strongly in the visible spectrum. Secondly, it is the infrared absorbing property of the molecule when it is not in solution that is more important in this particular application than when it is solvated. That is, whether the ratio of infrared absorption to visible absorption of the colorant on a surface is still acceptable for use as a security ink or like applications. This was brought into question by such groups as D. Keil, H. Hartmann and C. Reichardt, Leibigs Ann. Chem. 935 (1993). For example, they showed that when a croconate dye was deposited onto a polymer surface that the sharp infrared absorption peak becomes a very broad peak that contains a large shoulder in the visible part of the spectrum. This may be explained by the lack of rigidity of the molecule, which may be maintained while in a solvent, and/or that intermolecular interactions with other molecules, while not in a solvent, causes a hypsochromic shift of the absorption peak. A molecular dynamics simulation of a typical squarylium dye shows that the infrared absorption peak becomes spread out so much so that the ratio of infrared to visible absorption decreases by about two orders of magnitude. Hence the rigidity of conventional infrared dyes needs to be addressed and/or a possible method is used to decrease intermolecular interactions when they are deposited onto a surface. SUMMARY OF THE INVENTION

A first embodiment of the invention is a molecule 1

1 2 where m and n are the number of fused 6-membered aromatic rings connected to each side of the central moiety such that the first 6-membered aromatic ring, if present, is connected as shown in 1; and where Qi and Q₂ are one of the same or different fused rings shown as 2 whereby one ring shown as 2 is connected at any of the two adjoining positions to C₄ at any orientation and another ring shown as 2 is connected to any of the two adjoining positions C₅ to C₈ at any orientation of the outer aromatic rings shown in 1 which may also include one or many substituents individually selected from the group consisting of R a fused 5-membered ring or a 6-membered aromatic ring optionally substituted with 1 to 4 substituents individually selected from R₂, and fused polyaromatic rings optionally substituted with one or more substituents selected from R₃ where R], R₂ and R₃ are individually selected from the group R; and where Xι and X₂ are individually selected from the group consisting of CO, O, S, Se, Te, CR₄R_5, NR₄, S1R₄R₅, GeRiRs, PR₄ where R₄ and R₅, which may be the same or different, are selected from the group R; and where Y is individually selected from the group consisting of CO, O, S, Se, Te, CRβR _, NR₆, SiRβR-₇, GeR₆R , PRβ and Z is selected from CR₈ or N where R₆, R₇ and R₈ which may be the same or different, are selected from the group R; and where Z is individually selected from the group consisting of CO, O, S, Se, Te, CR₉R_10, NR₉, SiR₉Ri₀, GeRgRio, PR₉ and Y is selected from CR_n or N where R₉, Rι₀ and R_u which may be the same or different, are selected from the group R; and

Q₃ and Q₄ may be 0, 1 or more than 1 substituents that are individually selected from the group consisting of Rι₂, a fused 5-memebered ring or a 6-membered aromatic ring optionally substituted with 1 to 4 substituents individually selected from R₁₃, and fused polyaromatic rings optionally substituted with one or more substituents selected from R_u where R₁₂, R_J3 and R₁₄ are individually selected from the group R; and

R is the group consisting of a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted aralkyl group, a halide atom, a hydroxy group, a substituted or unsubstituted amine group, a substituted or unsubstituted alkoxy group; where the infrared dye absorbs strongly in the near infrared region of the spectrum but poorly in the visible region of the spectrum.

A preferred form of the invention is an infrared dye composition comprising a molecule as described herein.

A further preferred form of the invention is an infrared absorbing compound comprising a molecule as disclosed herein where one or more polar group substituents such as -S0₃H, -NH₂ and -CN are utilized.

A further preferred form of the invention is a solvent-based ink composition comprising a molecule as disclosed herein.

A further preferred form of the invention is a solvent-based ink jet printer ink composition comprising a molecule as disclosed herein.

BRIEF DESCRIPTION OF DRAWINGS

Preferred and other embodiments of the invention will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which: Figure 1 shows a calculated absorption spectrum for dye molecule 3; Figure 2 shows a calculated absorption spectrum for dye molecule 4; Figure 3 shows a calculated absorption spectrum for dye molecule 5; Figure 4 shows a calculated absorption spectrum for dye molecule 6; Figure 5 shows a calculated absorption spectrum for dye molecule 7;

BACKGROUND AND APPLICATION INFORMATION Conventional croconium and squarylium dyes have high wavelength absorption peaks, typically from 700 to 900 nanometers. The croconate dyes of Simard et al (supra) actually extend up to 1081 nanometers. However, the ratio of near infrared absorption, that is absorption from 700 to less than about 2000 nm in wavelength, to visible absorption for the squarylium or croconate dyes is not sufficient when deposited onto a surface. We have found that an improvement of this ratio can be achieved by using a molecule that is shown as 1.

1

wherein m and n are the number of fused 6-membered aromatic rings connected to each side of the central moiety such that the first 6-membered aromatic ring, if present, is connected as shown in 1; and wherein Qi and Q₂ are one of the same or different fused rings shown as 2 whereby one ring shown as 2 is connected at any of the two adjoining positions to C at any orientation and another ring shown as 2 is connected to any of the two adjoining positions C₅ to C₈ at any orientation of the outer aromatic rings shown in 1 which may also include one or many substituents individually selected from the group consisting of Ri, a fused 5-membered ring or a 6-membered aromatic ring optionally substituted with 1 to 4 substituents individually selected from R₂, and fused polyaromatic rings optionally substituted with one or more substituents selected from R₃ wherein Ri, R₂ and R₃ are individually selected from the group R; and wherein Xi and X₂ are individually selected from the group consisting of CO, 0, S, Se, Te, CR₄R_5? NR₄, SiRφRs_, GeR₄R₅₎ PR₄ where R» and R₅, which may be the same or different, are selected from the group R; and wherein Y is individually selected from the group consisting of CO, O, S, Se, Te, CRβR_?, NR₆, S1R₆R_7, GeRβRy_, PR₆ and Z is selected from CR₈ or N where R₆, R₇ and R₈ which may be the same or different, are selected from the group R; and wherein Z is individually selected from the group consisting of CO, O, S, Se, Te, CR₉R₁₀, NR₉,

SiR₉R₁₀, GeR₉R_10ι PR₉ and Y is selected from CRπ or N where R₉, Rio and Rn which may be the same or different, are selected from the group R; and

Q₃ and Q₄ may be 0, 1 or more than 1 substituents that are individually selected from the group consisting of Rι₂, a fused 5-memebered ring or a 6-membered aromatic ring optionally substituted with 1 to 4 substituents individually selected from R_J3, and fused polyaromatic rings optionally substituted with one or more substituents selected from R_w wherein Rι₂, R₁₃ and R₁₄ are individually selected from the group R; and

R is the group consisting of a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted aralkyl group, a halide atom, a hydroxy group, a substituted or unsubstituted amine group, a substituted or unsubstituted alkoxy group. Accordingly, in a first aspect, the present invention provides an infrared dye, characterised in that the dye comprises of a molecule shown in 1.

In a second aspect, the present invention provides indicia form for an infrared dye according to 1 formed on a substrate. The substrate may be paper, polymer, and the like. The indicia may be printed characters, shapes that any machine readable instrument or visual markings that may be detected.

In order that the present invention may be more readily understood we provide the following non- limiting embodiments.

The formula for specific examples of dyes in accordance with the present invention are given below. Examples of infrared dyes in accordance with the present invention comprise of the molecules 3 to

7 given below.

The absorption spectra for 3 to 7 were calculated and are given in Figures 1 to 5 respectively. As can be seen from the spectra, the compounds in accordance with the present invention have absorption peaks in the near infrared and a high ratio of infrared absorption at the compound's peak position to the absorption in the visible region.

Throughout this specification the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.

It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the invention as shown in the specific embodiments without departing from the spirit or scope of the invention as broadly described. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.

The present invention has been described with reference to a preferred embodiment and number of specific alternative embodiments. However, it will be appreciated by those skilled in the relevant fields that a number of other embodiments, differing from those specifically described, will also fall within the spirit and scope of the present invention. Accordingly, it will be understood that the invention is not intended to be limited to the specific embodiments described in the present specification, including documents incorporated by cross-reference or reference as appropriate.

Claims

An infrared dye wherein the dye comprises of a molecule 1

wherein m and n are the number of fused 6-membered aromatic rings connected to each side of the central moiety such that the first 6-membered aromatic ring, if present, is connected as shown in 1; and wherein Qi and Q₂ are one of the same or different fused rings shown as 2 whereby one ring shown as 2 is connected at any of the two adjoining positions Ci to C₄ at any orientation and another ring shown as 2 is connected to any of the two adjoining positions C₅ to C₈ at any orientation of the outer aromatic rings shown in 1 which may also include one or many substituents individually selected from the group consisting of Ri, a fused 5-membered ring or a 6-membered aromatic ring optionally substituted with 1 to 4 substituents individually selected from R₂, and fused polyaromatic rings optionally substituted with one or more substituents selected from R₃ wherein Rι,R₂ and R₃ are individually selected from the group R; and wherein X_t and X₂ are individually selected from the group consisting of CO, O, S, Se, Te,

CRjJR._5, NR₄, SiR+Rs_, GeRφ s, PR₄ where R₄ and R₅, which may be the same or different, are selected from the group R; and wherein Y is individually selected from the group consisting of CO, O, S, Se, Te, CRβRy_, NR₆, SiRβRv_, GeR^, PRβ and Z is selected from CR₈ or N where R₆, R₇ and R₈ which may be the same or different, are selected from the group R; and wherein Z is individually selected from the group consisting of CO, O, S, Se, Te, CRgRι_0, NR₉, SiRgR₁₀, GeR₉Rιo, PR₉ and Y is selected from CRπ or N where R₉, R₁₀ and Rπ which may be the same or different, are selected from the group R; and

Q₃ and Q₄ may be 0, 1 or more than 1 substituents that are individually selected from the group consisting of Rι₂, a fused 5-memebered ring or a 6-membered aromatic ring optionally substituted with 1 to 4 substituents individually selected from Rι₃, and fused polyaromatic rings optionally substituted with one or more substituents selected from R_M wherein Rι₂, R_!3 and Rι₄ are individually selected from the group R; and

R is the group consisting of a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted aralkyl group, a halide atom, a hydroxy group, a substituted or unsubstituted amine group, a substituted or unsubstituted alkoxy group; wherein the infrared dye absorbs strongly in the near infrared region of the spectrum but poorly in the visible region of the spectrum.

2. An infrared dye composition comprising a compound that can be described by molecule 1 according to claim 1.

3. A solvent-based ink composition comprising a compound that can be described by molecule 1 according to claim 1.

4. An infrared absorbing compound according to claim 1 wherein one or more polar group substituents such as -S0₃H, -NH₂ and -CN are utilized.

5. A solvent-based ink according to claim 3 which is ink jet printer ink.