MONOAZO COLORANTS

Abstract: Monoazo colorants represented by the general formula (I): (wherein X represents a hydrogen atom or a halogen atom, and Y represents a nitro group, a lower alkylsulfonyl group, a thiocyanic acid group or a halogen atom), or (wherein P represents a nitro group or a lower alkylsulfonyl group, and Q and T each represents a hydrogen atom, a hal­ ogen atom or a cyano group); R¹ and R² each represents an ethylene group or a pro­ pylene group; R³ and R⁴ each represents a hydrogen atom or an alkyl group which may be substituted by a lower alkoxy group or a lower alkoxyalkoxy group; and Z represents a halogen atom. This monoazo colorants include a reactive type pyridine-­ based monoazo dye suitable for use in dyeing of cellulose or cellulose/polyester mixed fibers in red to orange.

Description: The present invention relates to monoazo colorants. More particularly, it relates to reactive pyridine-based monoazo colorants suitable for dyeing cellulose (cotton) and mixed fibers of cellulose and polyester in orange to red color. Reactive pyridine-based monoazo colorants having the formulae (1) and (2) as shown below have been known to be colorants having excellent light fastness and wet colored fastness which permit dyeing of mixed fibers of cellulose and polyester. The monoazo colorants of formulae (1) and (2) are disclosed in JP-A 15558/83 and 47060/83. The colorant having the formula (1), however, has the drawback that the rubbing fastness after dyeing is poor because in dyeing mixed fibers of cellulose and polyester in dense color, the dyeing ability is insufficiently low and thus the colorant remains on the fiber surface which is not completely dyed. On the other hand, the colorant having the formula (2) has the drawback that in dyeing of mixed fibers of cellulose and polyester in dense color, the solvent fastness e.g., resistance against dry cleaning is poor although the rubbing fastness is relatively acceptable. An object of the present invention is to provide new orange to red monoazo colorants excellent in both the rubbing fastness and solvent fastness. The present invention relates to monoazo colorants represented by the general formula (I): wherein: wherein X represents a hydrogen atom or a halogen atom; and Y represents a nitro group, a lower alkylsulfonyl group, a thiocyanic acid group or a halogen atom, or D represents a group of the general formula wherein P represents a nitro group or a lower alkylsulfonyl group; and Q and T each represent a hydrogen atom, a CF₃ group, a halogen atom or a cyano group; R¹ and R² each represent an ethylene group or a propylene group; R³ and R⁴ each represent a hydrogen atom or an C₁-C₈ alkyl group which may be substituted by a lower alkoxy group or a lower alkoxyalkoxy group; and Z represents a halogen atom. The colorants represented by the general formula (I) have two structural features. One of the features is that the triazine ring is linked to the pyridine ring of the coupler through a bonding group of the formula _NH-R¹-O-R²-O_. The other is that the monoazo colorants contain a specified diazo component and the pyridine ring of the coupler is substituted by three groups consisting of a methyl group, a cyano group and a group of The diazo component is particularly preferably a benzothiazole component. The monoazo colorants of the present invention are basically water-insoluble and of the same type as disperse dyes which have heretofore been used as colorants for polyester fibers. The monoazo colorants of the present invention, however, are different from the conventional disperse dyes since the colorants additionally have a group capable of reacting with a cellulose fiber such as halogenotriazine in their structure. That is, the monoazo colorants of the present invention are a new type of colorants so-called as "reactive disperse dye". In the monoazo colorants represented by the above general formula (I), the halogen atom represented by X, Y, Q and T includes a chlorine atom, a bromine atom and a fluorine atom. Particularly preferred is a chlorine atom. The lower alkylsulfonyl group represented by Y and P includes a methylsulfonyl group, an ethylsulfonyl group, a propylsulfonyl group and a butylsulfonyl group. The halogen atom represented by Z includes a fluorine atom, a chlorine atom and a bromine atom. Particularly preferred is a fluorine atom. The alkyl group represented by R³ and R⁴ is an alkyl group having 1 to 8 carbon atoms, such as a methyl group, an ethyl group, a straight or branched propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group and an octyl group, or an alkyl group substituted by a lower alkoxy group or lower alkoxyalkoxy group, such as a 3-methoxypropyl group, and ethoxyethyl group, a 3-ethoxypropyl group, a 3-propoxypropyl group, a 3-isopropoxypropyl group, a 3-butoxypropyl group, a butoxyethyl group, a 3-isobutoxypropyl group, a methoxyethoxyethyl group and an ethoxypropoxypropyl group. As the group a monoalkyl amine group substituted by a lower alkoxy group is particularly preferred. The monoazo colorants represented by the general formula (I) can be easily prepared by diazotizing an amine compound represented by the general formula (II): wherein D is as defined above by known techniques and then coupling the diazotized amine compound to a compound represented by the general formula (III) wherein R¹, R², R³, R⁴ and Z are as defined above. In preparing the coupling component, a compound having the formula: is first reacted with aniline and then reacted with a compound represented by the general formula (IV): wherein R¹ and R² are as defined above to form a compound represented by the general formula (V): wherein R¹ and R² are the same as defined above. In this case, a small amount of a compound represented by the general formula (VI): is contained. In some cases, therefore, the coupling component contains, as well as the compound of the general formula (III), a small amount, e.g., not more than 10 wt% of the compound represented by the general formula (III′) shown below. Even with this coupling component, the effects of the present invention can be obtained. General formula (III′) wherein R¹, R², R³, R⁴ and Z are as defined above. The monoazo colorants of the present invention are available for various applications; for exemple, they can be used as colorants for dyeing of fibers and cloth, colorants for coloring of paper and plastics, or colorants such as an ink for an ink jet type printer. In general, the colorants of the present invention are mainly used as dyes. Thus the present invention will hereinafter be explained with reference to the case that the colorants of the present invention are used as monoazo colorants. Fibers which can be dyed with the colorants of the present invention include fibers of cellulose (cotton), flax, etc.; viscose rayon, copper ammonia rayon, etc.; partially aminated or partially acylated cellulose; polyester, polyamide, nylon, wool, silk, polyurethane, cellulose diacetate, cellulose triacetate, etc.; and cloth, mix spinned cloth, mix woven cloth, knit cloth, etc. produced of the above fibers. These are hereinafter referred to as "fibers ". The colorants of the present invention are particularly useful in dyeing of cellulose-polyester mixed fibers. That is, the colorants of the present invention act both as a disperse dye and a reactive dye, and thus can be used to dye cellulose and polyester at the same time. In the practice of dyeing, it is desirable for the colorants of the general formula (I) to be finely dispersed in a medium in the size of about from 0.5 to 2 µm. For this purpose, the following methods can be employed. (1) The colorants are finely dispersed in water using, for example, a Pluronic type nonionic surface active agent or a water-soluble dispersing agent composed of an anionic dispersing agent such as sodium ligninsulfonate and the sodium salt of a naphthalenesulfonic acid-formalin condensate and by the use of a pulverizing machine such as a sand mill. (2) The colorants are finely dispersed in an organic solvent such as alcohols, ketones, hydrocarbons, halogenated hydrocarbons, esters, ethers or mixtures thereof using, for example, compounds obtained by adding a low mol of ethylene oxide to sulfosuccinic acid esters, nonylphenol and the like. (3) The colorants are finely dispersed in a mixed solvent of water and a solvent compatible with water in any ratio, among the above solvents. At the above fine dispersion step, for example, polymer compounds soluble in the dispersion medium or surface active agents having a function other than dispersibility may be added. This fine dye dispersion can be used as it is as a dye bath for use in the dip dyeing method and the padding dyeing method, and further as a color paste for use in the print dyeing method. In general, the fine dye dispersion prepared by the above method is diluted with water, aqueous solutions of organic solvents, petroleum hydrocarbons, halogenated hydrocarbons, etc. to the desired dyeing concentration to form an O/W type or W/O type emulsion, and is used as a dip dyeing bath, a padding dyeing bath or a print dyeing color paste. In preparation of the dip dyeing bath, padding dyeing bath or print dyeing color paste, an alkali metal compound or an alkali precursor compound generating an alkali on heating in the presence of water, for example, can be added as an acid binder. The acid binder is usually used in such an amount that the pH of the dip dyeing bath, padding dyeing bath or print dyeing color paste is within the range of from 7.5 to 9.0. In the case of dyeing fibers containing cellulose, it is preferred that a cellulose fiber swelling agent be added to the bath or color paste. The amount of the cellulose fiber swelling agent used is from 5 to 25 wt%, preferably from 6 to 12 wt% of the bath or color paste. In dyeing the above fibers with the colorants of the present invention, known techniques can be employed. For example, the fibers are impregnated or printed with the dyeing bath or color paste prepared according to the above method, dried and subjected to heat treatment, and thereafter washed with hot water containing a surface active agent. A relation between a preferred dyeing method using the colorants of the present invention and fibers is shown in Table 1. Fibers dyed in orange to red color which are vivid and uniform in dyeing, good in light fastness and further excellent in rubbing fastness and solvent fastness can be obtained by dyeing with the colorants of the present invention. The present invention is described in greater detail with reference to the following examples. Example 1 A dye composition having the above constituents was finely dispersed by the use of a paint shaker as a fine dispersing machine to prepare a dye dispersion. Using the above dye dispersion, a print dyeing color paste (pH = 8.0) having the following constituents was prepared. The print dyeing color paste was printed on a polyester/cotton (65/35) mix spinned cloth by the use of a screen print dyeing machine, was subjected to intermediate drying at a temperature of 80°C for 3 minutes followed by fixing at a temperature of 185°C for 7 minutes by the use of a H.T.S. machine (high temperature steam fixing machine). Thereafter the cloth was washed with water and then washed with a washing liquid containing 2 g/ℓ of a nonionic surface active agent (Lipotoll TC-300 produced by Nikka Kagaku Co., Ltd.) and 1 g/ℓ of sodium carbonate at a bath ratio of 1: 30 at a temperature of 80°C for 10 minutes to obtain a vivid red-dyed cloth. The dyed cloth was tested for light fastness, rubbing fastness and dry cleaning fastness by the following methods according to a Japanese Industrial Standard (JIS). Light fastness: According to JIS L-0842 Rubbing fastness: According to JIS L-0849 Dry cleaning fastness: According to JIS L-0860 The results are shown in Table 2. The dye used in this example was prepared as follows: 20.3 g of a compound having the following formula: was added to 140 g of acetone and cooled to a temperature of -5°C, and then 9.7 g of trifluorotriazine were gradually added and stirred for 1 hour. Then 7.2 g of triethylamine were added and stirred for 30 minutes. In addition, 8.0 g of ethoxypropylamine were added to obtain an acetone solution of a compound having the following formula: 560 g of methanol were added to the above solution to prepare a coupling solution. To obtain a diazo solution, 15.7 g of 4,6-dichlorobenzothiazole were added to 120 g of acetic acid and 200 g of phosphoric acid, and 25.1 g of 47% nitrosulfuric acid were added at a temperature of from 0°C to -3°C and stirred to achieve diazotization. The diazo solution thus obtained was gradually added to the above coupling solution while controlling the temperature to a value of not higher than 0°C and the pH within the range of 2 to 4. After stirring for 2 hours, crystals precipitated were separated by filtration, washed with water and dried to obtain 46 g of red crystals. λmax (DMF) of the crystals was 508 nm. Comparative Examples 1 to 3 With comparative dyes having the formulae shown in Table 2, dyeing was performed in the same manner as in Example 1, and the dyed cloth was evaluated in the same manner as in Example 1. The results are shown in Table 2. Example 2 15 g of monoazo colorants having the formula: 5 g of polyoxyethylene glycol nonylphenyl ether (HLB 13.3), and 3 g of a naphthalenesulfonic acid-formaldehyde condensate were finely dispersed in 77 mℓ of water by the use of a sand mill to prepare a dye dispersion. Using this dye dispersion, a padding bath having the following constituents was prepared. Polyester/cotton (65/35) mix spinned cloth was impregnated with the above padding bath and wrung at a squeezing rate of 65% and, thereafter, dried at a temperature of 100°C for 2 minutes and heated at a temperature of 210°C for 1 minute to fix the dye. The above cloth was soaked in an alkali bath having the following constituents: was wrung at a squeezing rate of 60%, and then was subjected to steaming treatment at a temperature of 100°C for 45 seconds. Then the cloth was washed with water and cleaned in the same manner as in Example 1 to obtain a red dyed cloth having the following properties: The dye used in this example was prepared in the same manner as in Example 1, and λmax (DMF) of the cake was 508 nm. Example 3 10 g of a monoazo dye having the following structural formula: and 25 g of a naphthalenesulfonic acid-formaldehyde condensate were finely dispersed in 65 mℓ of water by the use of a sand mill to prepare a dye dispersion. Using this dye dispersion, a dyeing bath (pH 8.0) having the following constituents was prepared. 10 g of Nylon taffeta were dipped in the above dyeing bath (pH 8.0), heated gradually from room temperature to 95°C and dyed at this temperature for 1 hour. The Nylon taffeta was subjected to the same cleaning treatment as in Example 1 to obtain a red dyed product having the following properties: The dye used in this example was prepared in the same manner as in Example 1, and λmax (DMF) of the cake was 504 nm. Example 4 15 g of a (about 1: 1) mixture of monoazo colorants having the following formulae: and 10 g of a Pluronic surface active agent (Pluronic L64 produced by Asahi Denka Kogyo Co., Ltd.) were finely dispersed in 75 mℓ of water by the use of a sand mill as a fine dispersion machine to prepare a dye dispersion. Using this dye dispersion, a print dyeing color paste (pH 8.0) having the following constituents was prepared. A cotton broad (cotton yarn number: 40) subjected to mercerization was print-dyed with the above print dyeing color paste (pH 8.0) by the use of a screen print dyeing machine, was subjected to an intermediate drying at a temperature of 80°C for 3 minutes, and followed by subjecting to a treatment using superheated steam at a temperature of 185°C for 7 minutes. Thereafter the same cleaning treatment as in Example 1 was applied to obtain a red-dyed product having the following properties: Light fastness Class 5 The dye used in this example was prepared in the same manner as in Example 1, and λmax (DMF) of the cake was 508 nm. Example 5 15 g of an azo colorants having the formula: and 15 g of a naphthalenesulfonic acid-formaldehyde condensate were finely dispersed in 70 mℓ of water to prepare a dye dispersion. Using this dye dispersion, a padding bath having the following constituents was prepared. Polyester fiber cloth was impregnated with the above padding bath and wrung at a squeezing rate of 45% and, thereafter, dried at a temperature of 100°C for 2 minutes, fixed for 7 minutes in superheated steam maintained at a temperature of 185°C and then subjected to reduction cleaning by the known procedure to obtain a red-printed cloth having a light fastness of Class 5. max (DMF) of the dye was 509 nm. Example 6 Polyester/cotton (65/35) mix spinned cloth was dyed with the dyes shown in Table 3 in the same manner as in Example 1 to obtain dyed cloth colored in the colors shown in Table 3. The dyed cloth was measured for rubbing fastness (dry). The results are shown in Table 3. Example 7 Nylon taffeta was dyed with the dyes shown in Table 4 in the same manner as in Example 3 to obtain dyed cloth colored as shown in Table 4. The light fastness and dry cleaning fastness of the dyed cloth were respectively Class 5 and Class 5. Example 8 Print dyeing was performed in the same manner as in Example 1 except that the polyester/cotton (65/35) mix spinned cloth was replaced with polyester/silk (65/35) mix spinned cloth, thereby obtaining a sharp red-dyed product. The dyed product shows excellent color fastness in light fastness, rubbing fastness and dry cleaning fastness. While the invention has been described in detail and with reference to specific embodiment thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof.

Claims: 1. Monoazo colorants represented by the general formula (I): wherein: wherein X represents a hydrogen atom or a halogen atom, and Y represents a nitro group, a lower alkylsulfonyl group, a thiocyanic acid group or a halogen atom, or D represents or group of the general formula wherein P represents a nitro group or a lower alkylsulfonyl group, and Q and T each represent a hydrogen atom, a CF₃ group, a halogen atom or a cyano group; R¹ and R² each represent an ethylene group or a propylene group; R³ and R⁴ each represent a hydrogen atom or a C₁-C₈ alkyl group which may be substituted by a lower alkoxy group or a lower alkoxyalkoxy group; and Z represents a halogen atom. 2. The monoazo colorants according to Claim 1, wherein the colorants are represented by the general formula (I′): wherein: X represents a hydrogen atom or a halogen atom; Y represents a nitro group, a lower alkylsulfonyl group, a thiocyanic acid group or a halogen atom; R¹ and R² each represent an ethylene group or a propylene group; and R³ and R⁴ each represent a hydrogen atom or an C₁-C₈ alkyl group which may be substituted by an lower alkoxy group or a lower alkoxyalkoxy group. 3. The monoazo colorants according to Claim 1, wherein the colorants are of a following formula: 4. The monoazo colorants according to Claim 1, wherein the colorants are reactive type dispersion dyes for dyeing polyester and cellulose mixed fibers at the same time. 5. The use of the monoazo colorants according to any one of claims 1 to 3 for dyeing or printing cotton or mixed fibers of cellulose and polyester.

Inventors: TOSHIO, HIHARA, YUKIHARU, SHIMIZU
Applicants: MITSUBISHI KASEI CORPORATION
Application year: 1987
Main classification: C09B62
IPC codes: D06P3, D06P1, C09B62