[0001] This invention relates to novel copper phthalocyanine amine derivatives and their specific chemical synthesis, as well as a colorant, i.e. a dye or a pigment, from this novel copper phthalocyanine compound or mixtures thereof with varying degrees of amination, in particular a colorant containing said copper phthalocyanine compounds used for doping a polycarbonate in bulk for the purpose of imparting the properties of a near infrared (NIR) absorbing filter, with low absorptivity in the visible light region. The novel phthalocyanine compounds allow for an effective heat ray shielding material to be formed thereof.

[0002] Phthalocyanine compounds exhibit superior thermal and chemical stability due to their structural characteristics. They represent large ring structures formed by coordinate bonds between a center metal atom surrounded by four nitrogen atoms belonging to the macrocycle isoindole fragments. Depending on the type of the central metal or the substituents in the macrocycle benzene fragments, the absorption properties of phthalocyanine derivative vary. Therefore, phthalocyanine compounds allow for many applications covering various fields. They are widely employed as dyes and pigments, e.g. as pigments for CDs, pigments applied in organic photo conductors for laser printing, NIR absorption pigments of NIR absorption filters for displays such as PDPs (plasma display panels). As the plasma display industry is expanding rapidly, the significance of NIR absorption filters increases likewise.

[0003] Plasma displays entail the problem that in the course of plasma discharge (glow discharge) NIR radiation is also emitted, which is then manifest as interference radiation, inducing malfunctioning of electrical apparatuses. A NIR absorption pigment for PDPs must have high light absorption properties in the range between 750 to 950 nm wavelength. Moreover, high permeability to visible radiation should be provided in order to ensure high color reproductivity and full color gamut of display devices. Various compounds e.g. cyanine based, nickel-dithionyl based or diimmonium based compounds are available. However, such compounds have several drawbacks, including such as insufficient heat resistance, lack of durability in humid environment, or they are poorly soluble in certain solvents.

[0004] Phthalocyanine compounds however have superior characteristics in all of the above-mentioned respects, that is, they proof to be durable, weather and light resistant. Some substituted phthalocyanines are well soluble in various organic solvents. They are characterized by low light absorption in the visible region and high efficiency at cutting NIR radiation, which allows for selective absorption within this range. Consequently, they may be widely applied as a coating type NIR absorption pigment for PDPs.

[0005] If by choice of various central metals the maximum absorption wavelength range of the phthalocyanine compounds is shifted towards the longer wavelength region, as a by-effect, the light absorption in the region of particularly 750 to 900 nm becomes insufficient. Furthermore, what represents a severe drawback when introducing a phenol or a thiophenol as substituent in order to accomplish a bathochromic shift of the maximum wavelength absorption region, the transmittance in the visible light region decreases. Thus, the increase of absorption in the longer wavelength range is gained at the expense of color gamut and color reproduction. The same holds true for the absorption peaks, if they are too large in the range of 710 to 780 nm wavelength. As the absorption in one particular spectral range cannot be increased without suffering transmission in another range, a too high degree of absorption in the range of 710 and 780 nm will be obtained at the expense of transmission in the visible range. Thus, absorption in the neighboring visible range (400 to 700 nm) will increase, as the characteristic peak at lower wavelengths is shifted into the range of visible light (cf. figure 3). This consequently reduces illumination, which in many cases is not desirable. The basic problem is that the shape of the absorption curve is essentially given. Thus, its shifting along the wavelength ranges towards the longer wavelength region or the general increase of the absorptivity in a particular wavelength range will always be at the expense of some undesired effect in yet another wavelength region, e.g. suffering of trans mitta nee in the visible light range. Consequently, there is a conflict among the various objectives.

[0006] Polycarbonate materials are colorless, i.e. translucent. As they are relatively expensive, polycarbonates are used where other cheaper plastic materials are too soft, too fragile and/or dimensionally unstable. Polycarbonate materials are highly transparent to visible light (380 - 780 nm), with even better light transmission than many kinds of glass, which is why e.g. eyewear lenses are made of polycarbonate. However, as can be seen from figure 1 , the transmission spectrum of polycarbonates also exhibits high transmission in the NIR range up to a wavelength of 1650 nm, where they typically show an absorption peak, corresponding to a local transmission minimum. For still longer wavelengths, the transmission of polycarbonates increases again with the next absorption peak at about 2150 nm. Hence, polycarbonates as such - without any modifications or additives - may not be used as NIR absorption filters.

[0007] Polycarbonates may also be dyed by immersion into a mixture of dissolved dye or dispersed pigment in a solvent blend. Thus, by using a dye or pigment from phthalocyanine compounds, the property for absorbing NIR radiation may be imparted on the polycarbonate. Agents for absorbing NIR radiation often include polymethine dyes and phthalocyanine compound type dyes. The application of colorants, i.e. dyes or pigments, to polycarbonates is however not a straightforward task as problems arise with some colorants which show absorbing properties in the NIR region. These dyes or pigments may suffer their abilities to absorb NIR radiation when mixed with other dyes or pigments due to chemical reactions or inductive interactions. Moreover, in order to carry out a melt extrusion or a reaction of polymerization at elevated temperatures, thermally and chemically stable NIR absorbing material needs to be used. Many existing NIR absorbing colorants are unstable at higher temperatures and therefore poorly suited for polycarbonate or any polymer doping.

[0008] Many NIR absorbing colorants used today for doping polycarbonate or other polymer compounds are rather high-priced because the production processes involve multi-stage synthesis, high-energy consumption and the starting materials used are costly. For example EP 2 380 893 discloses copper phthalocyanine compounds and near-infrared absorption filters using the same. Judging from the examples provided in this document, nucleophilic substitution of fluorine atoms are being used to obtain the target compound. The regions of intensive absorption of this compound is within the IR range is 830-900 nm and this range does determine the fields of applications.

[0009] It is the aim of the present invention and method, to provide a compound for an strong absorption in the range of 750-820 nm and which is based on phthalocyanine green which is widely used in practice and which is incomparably easier the handle than the one according to this EP 2 380 893 which is using compounds that are very difficult to procure. In more detail, EP 2 380 893 claims a near-infrared absorption copper phthalocyanine compound represented by following Formula 1 :

wherein, A2, A3, A6, A7, A10, A1 1 , A14 and A15 are independently OR1 , SR2 or a halogen atom, wherein at least four of them are OR1 ; A1 , A4, A5, A8, A9, A12, A13 and A16 are independently OR1 , SR2, NR3R4 or a halogen atom, wherein at least two of them are NR3R4, and at least four of them are OR1 ; and R1 , R2, R3 and R4 are independently an alkyl group of 1 to 10 carbon atoms, an aryl group of 6 to 10 carbon atoms, or an aralkyl group of 7 to 15 carbonatoms. Starting from this know how, it is the aim of the present invention to teach an easily, savely and economically producible compound with high absorption within the IR range of 750-820nm that does neither comprise OR groups nor alkyl nor aryl groups. Apparently, nudeophilic substitution of fluorine atoms is being used according to EP 2 380 893 while the present invention - as will be shown - starts form a chloro-substituted compound. Hence, the method of preparation starting from widely practically used phthalocyanine green is incomparably easier than the proposed ones since their starting compounds are very difficult to obtain.

[0010] Various other similar compounds have been publish in the state of the art. A preliminary international search SN 66702 to the priority application of this present application revealed three relevant documents: DE 34 46 418 A1 and EP 1 577 350 A1 as well as the Scientific Publication of Ayfer K Burat et al: "Synthesis physiochemical properties and electrochemistry of morpholine-substituted phthalocyanines", Journal of Porphyrins and Phtalocyanines, Bd. 14, Number 7, 1 th July 2010, pages 605 to 614. These documents to the state of the art will be commented briefly in the following:

[0011] DE 34 46 418 A1 claims an optical recording medium, consisting of a substrate and a light-absorbing layer which is characterized in that the light-absorbing layer includes at least one dye having the following formula:

or contains at least one dye having this formula (I). In this formula, M means two hydrogen atoms for Cu, Ni, Pb, VO, TiO, Nb, Ta, Pd, Sn, Cr, Mn, Fe or Co, Y means

where R ¹ and R ² mean, independently of each other, hydrogen, Ci-Cs-alkyl, phenyl, phenyl-Ci-C ₄ - alkyl or Ci- Cs-oxyalkyl-C2- or C3-alkyl. The structures do not include any haloid atoms and therefore substantially differs from the strucuture of the present derivatives. Now, with respect to amine substituted phthalocyanines actually containing halogen atoms in the molecule - such ones have been described in K.A. Volkov, G.V. Avramenko, V.M. Negrimovsky, E.A. Lukyanets. Nucleophylic Substitution of Chlorine Atoms in Tetrachlorinephthalonitrile: The Synthesis of Phenyl-(Alkyl- )Amine-Substituted Phtalonitriles and Some Phthalocyanines on the Basis of the Same. Journal of General Chemistry. - 2008. - Vol. 78, Issue 9. - Pp. 1557-1563. They all contain amine groups in 4-positions. Therefore, they do not absorb in the near IR region. Amine derivatives of phthalocyanine were first studied by the inventors of this present application: 1 ) S.A. Mikhalenko, E.A. Lukyanets. Amine Derivatives of Phthalocyanine. Collected works Dye-Making and Dye-Using Industries, R&D Institute for Feasibility Studies in the Chemical Complex, No. 1 , 12 (1972); 2) S.A. Mikhalenko, E.A. Lukyanets. Dimethylamine Substituted Phthalocyanines. Journal of General Chemistry, 46, 2156 (1976); 3) S.A. Mikhalenko, V.M. Derkacheva, E.A. Lukyanets. Phthalocyanines and Related Compounds. XIX. Tetra- and Octo-Amine Substituted Phthalocyanines. Journal of General Chemistry, 51 , 1650 (1981 ). All of them were obtained by tetramerization of corresponding amine-substituted phthalocyanines that were first obtained by these inventors. It should be noted that the obtained phthalocyanines also included amine groups, both in 3-positions which are the closest ones to the macrocycle and in 4-positions that are distant from the macrocycle). It is important that in the near IR region, only the former ones are absorbing. As for the 4- substituted, their spectrum is slightly bathochromically shifted from the initial compounds.

[0012] EP 1577350 A1 does disclose a method for the production of halogen-containing phthalocyanine compound with a quite different objective than the present invention. This compound is dedicated to the production of halogen-substituted phthalocyanines by tetramerizaton of the corresponding amine-substituted phtalonitriles, that may include other substituents and in particular amine groups. However, no specific examples with absorption in the near IR region can be found in this document. Hence, such absorptions were not obtained.

[0013] The paper of Burat et al. only confirms the above: phthalo-nitrile- phthalocyanines obtained from the correspondingly substituted compound do not absorb in the near IR region, starting from 700 nm, which can be seen in the text of the paper. Therefore, this paper is not relevant for the objectives of the present invention.

[0014] In contrast to these above mentioned teachings, it is the objective and aim of the present invention to produce phthalocyanine green from the available halogen- substituted phthalocyanine, and in particular not from phthalonitrile, and this by means of its amination in one compound. The product shall absorb in the near IR region and feature solubility and stability that enables its technical application. The demand for industrial, large-scale inexpensive synthesis of such colorants, particularly also NIR absorbing colorants, has always been a key driver in research and development and the invention now offers exactly this. [0015] In view of the above, the objective of this present invention is it to provide a copper phthalocyanine amine compound with high absorptivity in the NIR range, especially in the region of 700 to 850 nm, and which exhibits high transmittance in the visible light region to provide clear and intense images with superior color gamut.

[0016] It is a further objective of the present invention to provide a copper phthalocyanine amine compound which provides high absorptivity of longer wavelengths than achieved up to date in the NIR range, the latter being responsible for malfunction of remote control, while providing high transmittance in the visible region.

[0017] It is also an objective of the present invention to provide a colorant using the copper phthalocyanine amine compound to yield a low-cost high thermoisolation which may be used in large amounts in a wide variety of fields, in particular in the building construction industry. Further, such compounds are also of use in the energy industry, for producing dye sensitized thin film solar cells in thin-layer photovoltaic devices.

[0018] A further objective of the present invention is it to provide an inexpensive, convenient and straightforward, selective and low energy consuming chemical synthesis for the said copper phthalocyanine amine compound, starting from low-cost raw materials of vast availability.

[0019] Yet another objective of this present invention is it to provide various uses of a copper phthalocyanine amine compound which exhibits excellent solubility in various liquid chlorinated organic solvents, as well as in polycarbonate in a molten state, and which is thermostable, photostable and weather resistant.

[0020] In order to achieve the above-mentioned objectives the present invention provides a compound according to claim 1 , a colorant according to claim 3, a method for a chemical synthesis according to claim 4, and various uses according to claims 9 to 14.

[0021] The present invention is explained, outlined and exemplified by means of the figures listed below, namely:

Fig. 1 exhibits the radiation transmittance of a polycarbonate plotted against the wavelength;

Fig. 2 shows the formula according to claim 1 ;

Fig. 3 shows the optical density of the formula according to claim 1 plotted against the wavelength in the range 300 - 900 nm;

Fig. 4 shows the Transmittal Solar Spectrum of doped polycarbonate makrolon plotted against the wavelength in the range 400 - 1600 nm.

[0022] The NIR absorption copper phthalocyanine compound according to the present invention as shown by the formula of figure 2 is an amine derivative of phthalocyanine green, the latter being a perchlorinated copper phthalocyanine with chlorine atoms in all 3-, 4, 5-, 6-positions of molecule (15 to 16 chlorine atoms in total). This copper phthalocyanine amine derivative shows a unique, characteristic chemical structure including fragments of morpholine with a nitrogen-carbon bond mostly in 3 and 6 positions of the macrocycle, and chlorine atoms in all other positions as shown in figure 2.

[0023] As can be taken from the curve in the diagram of figure 3, the copper phthalocyanine amine compound according to the present invention has maximum absorptivity in the range of 700 to 850 nm wavelength. In particular, it shows a local absorption maximum at wavelengths located at 790 nm. On the other hand, the transmittance of the compound in the visible wavelength region is high.

[0024] The heat thermoisolation effect is improved, if the copper phthalocyanine amine derivative is used in combination with another dye. Thus, if the thermoisolation effect of a copper phthalocyanine amine derivative is compared with that of only half of the amount of the copper phthalocyanine in combination, e.g., with carbon black, the quality of the thermoisolation turns out to be the same(!). Of course, the more carbon black is contained, the smaller the transmittance of visible light gets.

[0025] In order to provide for a heat radiation-shielding, the dye or pigment are added to a molten polycarbonate during its processing into a finished product by extrusion, giving it a color varying from light gray to dark purple, depending on the concentration of the dye. A polycarbonate resin containing the copper phthalocyanine amine derivative of the present invention may then be coated onto a transparent resin board. The phthalocyanine amine derivative in the coating exhibits excellent heat resistance properties compared to other available NIR absorbers. Consequently, these compounds may be molded with polycarbonate resins by injection or extrusion molding, where the resins are heated to temperatures of 350°C or more. This yields molds with excellent thermoisolation properties. The dye can also be added to a solution of polycarbonate in a chlorinated solvent to prepare a cast film (plate). The resulting heat radiationshielding material may adopt any shape, from flat board shapes to spherical, corrugated shapes etc. as well as any thickness. The dye or pigment can also be supplied as a granular super-concentrate, i.e. polycarbonate granules with a high concentration of the dye. The dye may also be used for producing camouflage having high pigment density to prevent detection by night-vision devices.

[0026] The amount of the copper phthalocyanine amine derivative which is to be used depends on which absorption properties in the NIR range and transmittance properties in the visible region are desired with the heat thermoisolation material. Moreover, the amount also depends on the thickness of a particular sheet. Figure 4 shows the solar spectrum through the sheet of polycarbonate, 2 mm thick, tinted with the novel copper phthalocyanine amine derivative with different weight percentages: C=0.000% (upper curve), C=0.005% (middle curve), C=0.010% (lower curve). Two vertical lines border the range of wavelengths corresponding to visible light (i.e. from about 390 to 700 nm). This range is neighbored to the right by the region of heat rays, i.e. the wavelength region from 800 to 1800 nm. As can be taken from the curves in figure 4, the higher the content of the copper phthalocyanine amine derivative, the better the absorption in the heatwave length range, resulting in an improved thermoisolation effect. The heat rays (800 - 1800 nm) are efficiently blocked, while but a minor impairment in the transmittance of visible light needs to be accepted. Thus, the heat insulation material which is provided by mean of the copper phthalocyanine amine derivative exhibits both superior thermoisolation while transmitting visible light to a very satisfying degree. The most preferable concentration of the copper phthalocyanine amine derivative will depend on the thickness of the particular thermoisolation material. The recommended concentration for a polycarbonate layer with a 2 mm thickness is 0.01 % of the polymer weight. [0027] The concentration distribution of the novel copper phthalocyanine amine derivative used must in no way be regular, provided that the issue of appearance does not impose any restrictions. What is more, even a mixture of copper phthalocyanine amine derivatives with varying degrees of amination may be used for dyeing a polycarbonate in bulk. When several compounds with different absorption properties are mixed, the heat radiation-shielding effect is increased.

[0028] The derivative(s) according to the invention entail(s) highly improved emulsifying and dispersing properties useful for the manufacture of coatings and paints. This makes the compound suitable for coating or painting inner and outer walls of buildings, namely as coating material for facades, doors and roofs, and also for glass fronts, glass doors, glass roofs and glass windows. Moreover, the radiation-shielding material according to the invention proves to be weather durable, so as to allow for many applications in a wide variety of fields, in particular in the construction and building industry, and even in the energy industry.

[0029] The chemical synthesis yielding the copper phthalocyanine amine derivative is a pressure amination process, which comprises preparing a mixture of phthalocyanine green pigment and morpholine, and replacing chlorine atoms of the phthalocyanine green pigment by morpholine at determined positions. Preferably, the mixture of phthalocyanine green pigment and morpholine is 1 :42 in weight.

[0030] The chemical synthesis is performed by heating the reaction mixture in a closed reactor. For this purpose, a sealable, preferably stainless steel reactor is used, the latter being equipped with a mixing and heating device and a bottom outlet. The reaction mixture is heated in the sealed reactor under agitation and under pressure. The reaction conditions such as the reaction temperature, the degree of agitation, the pressure and reaction time can be tuned with respect to the desired degree of morpholine amination at the 4-, 5-positions of the phthalocyanine green pigment, i.e. to yield copper phthalocyanine amine derivatives exhibiting 1 to 8 morpholine groups at the 4-, 5- positions and 8 to 16 chlorine atoms at the 3-, 6-positions of the phthalocyanine.

[0031] Preferably, the reaction mixture is heated to 150°C under agitation. The amination process lasts about 12 hours. Thereafter, the reaction product is left to cool down to room temperature and is drained through the bottom outlet of the reactor. The crude, isolated product is dried using a rotary evaporator connected to a vacuum network. To this end, heat is applied by means of a water bath, so that the reaction mass evaporates until no more distillate is produced. The syrup-like raw product is then transferred from the evaporation flask to a vacuum filter (a porcelain Buchner funnel with a Bunsen flask) at the residual pressure of 0.2 to 0.3 bar. The vacuum filter is equipped with a dual-layer filter membrane consisting of filtering paper and coarse calico. The product is flushed with water until chlorine ions can no longer be detected in the flush water. Finally, the water-flushed product is dried in a heating chamber at 90°C to constant weight. The resulting tridecane-morpholine-dichlorine-substituted copper phthalocyanine has a maximum absorption wavelength of 797 nm and an extinction coefficient of 54,700 l/mol ^* cm.

[0032] The inventive substance of these products is furthermore supported by the fact that they are surprisingly economic in production, provide various uses of a copper phthalocyanine amine compounds which exhibit excellent solubility in various liquid chlorinated organic solvents, as well as in polycarbonate in a molten state, and which are thermostable, photostable and weather resistant. Several points must be mentioned which show the advantages and particular characteristics of both the production process and the end product:

1 . The percentage of the raw material cost in the cost of the finished product is defined by the product output per one process cycle. The larger the amount of raw material loaded into the reactor, the higher the figures: 1 kg of the finished product - 3%, 10 kg - 15%, and so on.

2. The design of the technological and engineering process can be adapted to the standards and regulations of the country where the production facility will be located.

3. The quality of the products can be maintained by strict observance of the technological process, including the control of current parameters in the reference points, the input quality control of the raw materials as used for the production and assessment of the finished product characteristics. The methods of analysis used are conventional ones: spectral, thermal, and chromatographic.

4. The cost of the finished product can be indicated by a rough calculation with an assumed labor cost of USD 1500/month as follows: To obtain 1 kg of the finished product, 5.2 kg of the raw material are required with a total cost of about 15 US dollars. One operating cycle comprises 30 hours, or 5 shifts with a six-hour working da each. According to the regulations valid in most countries, the job must be performed by two operators. Therefore, the labour cost is 150 UDS in total for two operators per shift, or 750 USD per cycle. The approximate cost of water supply, electric power and the equipment and premises depreciation will be in the range of 30 USD. The overhead costs, as included in the salary fund, shall be approx. 20% - or 30 USD. In total: 15 + 750 + 30 + 30 = 826 USD per kg. The rise in price, as compared to the raw material, is therefore approx. 5.5 times. When producing 10 kg of the finished product, the cost will be as follows: Raw material: 150 USD; salary: 750 USD; water, electricity, depreciation: 60 USD; overheads: 30 USD. In total: 150 + 750 + 60 + 30 = 990 USD, or 99 USD per kg. The rise in price, as compared to the raw material, shall be seven times. The higher the reactor's loading, the lower the cost! With automation, it may be possible to manage the production process with just one operator.

[0033] In order to carry out a melt extrusion or a reaction of polymerization at elevated temperatures, thermally and chemically stable NIR absorbing material needs to be used. Many so far existing NIR absorbing colorants are unstable at higher temperatures and therefore poorly suited for polycarbonate or any polymer doping. The demand for industrial, large-scale inexpensive synthesis of such colorants, particularly also NIR absorbing colorants, has therefore always been a key driver in research and development. These products according to the present invention overcome the long known deficiencies.