Polymeric dispersants for disperse dyes

Abstract

The present invention relates to a polymeric dispersant useful for disperse dyes, comprising a random copolymer comprising styrenic monomer units and ethylenically unsaturated sulfonic acid monomer units. The present invention also relates to an aqueous disperse dye composition comprising the polymeric dispersant, and a process for producing the aqueous disperse dye composition.

Description

[Technical field]

[0001] The present invention relates to a polymeric dispersant useful for disperse dyes, comprising a random copolymer comprising styrenic monomer units and ethylenically unsaturated sulfonic acid monomer units. The present invention also relates to an aqueous disperse dye composition comprising the polymeric dispersant, and a process for producing the aqueous disperse dye composition. [Background technology]

[0002] Disperse dyes are widely used in the textile industry, especially for dyeing polyester fabrics. Traditionally, disperse dyes have been commercially supplied mainly in powder form (i.e., disperse dyes in powder form) for convenience of transportation and storage. Disperse dyes in powder form are generally compositions produced by grinding press cake of disperse dyes in the presence of suitable auxiliaries, such as fillers and dispersants, and water, and then spray drying to obtain powder. The production and application of disperse dyes in powder form necessarily involves handling of the powder, which poses occupational health hazards to workers exposed to dust generated during handling of the powder.

[0003] With the increasing demand and awareness of sustainability, manufacturers' interest in the traditional powder form of disperse dyes is gradually shifting to disperse dyes in liquid form (i.e., liquid form of disperse dyes). Liquid form of disperse dyes is an aqueous dispersion or suspension, which is generally produced by grinding disperse dye press cake in water in the presence of auxiliary agents. Compared with powder form of disperse dyes, liquid form of disperse dyes has a uniform dispersion of dye particles in the liquid, which increases dye uptake and improves color uniformity. The reduction washing step can be omitted to save water and energy. The increased dye uptake increases the dye utilization rate and therefore the dye level in the residual liquid. In addition, compared with the production of powder form of disperse dyes, the production of liquid form of disperse dyes uses less auxiliary agents (such as fillers) and reduces the level of chemical oxygen demand (COD) in the residual liquid. Furthermore, liquid form of disperse dyes is more compatible with the upgrade of automatic dyeing equipment such as padding and printing equipment, leading to reduced costs and increased throughput.

[0004] Liquid forms of disperse dyes have been less popular than powder forms of disperse dyes because liquid forms of disperse dyes have stability and viscosity issues in long-term storage that make them undesirable. Dispersants are essential to produce liquid forms of disperse dyes, as they facilitate the grinding of the press cake and produce a uniform, properly micron-sized particle size (typically in the range of 0.5 to 1 micron D). 50) and gives the suspension storage stability. The most common dispersants on the market are based on methyl naphthalene sulfonate formaldehyde condensates (MF), benzyl naphthalene sulfonate formaldehyde condensates (CNF), sulfonated phenol formaldehyde condensates, lignin sulfonates, or combinations thereof. Although these common dispersants provide basic dispersing ability and are very cost-effective, they are not satisfactory for the following reasons: Disperse dyes in liquid form produced with these dispersants do not have sufficient long-term storage stability. These dispersants need to be used in relatively large amounts, typically more than 15% relative to the disperse dye. High dispersant dosages usually have a negative effect on dyeing performance. The performance of these dispersants varies greatly depending on the type of dye and the quality of the press cake. Dispersion performance is often insufficient for certain types of disperse dyes. In addition, some conventional dispersants often contain harmful chemicals such as formaldehyde and phenol.

[0005] Other dispersants for aqueous colorant systems have also been developed, for example, an anionic copolymer of styrene / maleic anhydride / sodium ethyl allyl sulfonate was proposed in CN1102843121A as a dispersant for disperse dye inks to solve the problem of precipitation in jet inks with small particles below 0.2 microns.

[0006] JP 2000-273373A describes a water-soluble polymer as a dispersant in an aqueous jet ink for dispersing water-insoluble, nano-sized colorants such as organic pigments, inorganic pigments, disperse dyes, and oil-soluble dyes. The water-soluble polymer contains, in the form of a free acid, a carboxylic acid group, one or more other acid groups such as sulfonic acid groups and / or phosphoric acid groups, and further a hydrophobic group that is favorable in terms of storage stability. Jet inks containing the water-soluble polymer were described to have various good performances, including one-week storage stability. However, the long-term storage stability of aqueous disperse dye dispersions with larger particle sizes was not tested in this patent application. It is known that the poor storage stability of aqueous disperse dye dispersions with nano-sized particles is mainly due to particle aggregation, while the poor storage stability of aqueous disperse dye dispersions with micron-sized particles is mainly due to particle settling. Meanwhile, the textile industry typically uses dyes with micron-sized particles that are limited by milling equipment and milling efficiency. Therefore, it cannot even be predicted that a water-soluble polymer would have the effect of improving the long-term storage stability of disperse dyes in liquid form. Summary of the Invention [Problem to be solved by the invention]

[0007] There is a need to provide a dispersant useful for disperse dyes in liquid form that does not suffer from the above disadvantages, particularly useful for disperse dyes in liquid form having particle sizes of 0.5 microns or greater. [Means for solving the problem]

[0008] It is an object of the present invention to provide a dispersant useful for producing a liquid form of a disperse dye having desirable long-term storage stability, preferably at a lower dosage than conventional dispersants. It is a further object of the present invention to provide a liquid form of a disperse dye and a process for producing the same.

[0009] It has now been found that the objects of the present invention can be achieved by a random copolymer comprising styrenic and ethylenically unsaturated sulfonic acid monomer units.

[0010] Thus, in a first aspect, the present invention provides a monomeric unit: a) 15 to 45% by weight of styrene monomer units; b) 30 to 60% by weight of ethylenically unsaturated sulfonic acid monomer units in unneutralized, partially neutralized or fully neutralized form, and c) providing a polymeric dispersant comprising a random copolymer comprising or consisting of 0 to 40% by weight of ethylenically unsaturated monomer units other than monomer units a) and b);

[0011] In a second aspect, the present invention provides a method for producing a pharmaceutical composition comprising the steps of: i) a disperse dye; ii) a random copolymer as described herein; and iii) water, In this case, the random copolymer and the disperse dye are present in a weight ratio ranging from 1:50 to 1:3.

[0012] In a third aspect, the present invention provides a process for producing an aqueous disperse dye composition comprising grinding one or more presscakes of a disperse dye in water in the presence of a polymeric dispersant as described herein. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] The present invention will now be described in detail below. It should be understood that the present invention can be embodied in many different ways and should not be construed as being limited to the embodiments set forth herein. Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs.

[0014] As used herein, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise.

[0015] As used herein, the terms "comprise", "comprising", and the like are used interchangeably with "contain", "containing", and the like, and are to be construed in an open, non-exclusive manner. That is, for example, additional components or elements may be present. "Consisting of" or cognate expressions may be subsumed within "comprising" or cognate expressions.

[0016] As used herein, the term "polymeric dispersant" refers to a composition having dispersing capacity and comprising a polymer as the active substance, any auxiliaries from the preparation of the polymer, and optionally a solvent.

[0017] As used herein, the term "disperse dye in liquid form" has its ordinary meaning in the art and in particular refers to a disperse dye product supplied in the form of an aqueous composition comprising a disperse dye and any adjuvants such as dispersants.

[0018] In a first aspect, the present invention provides a polymerizable composition comprising the following monomeric unit: a) 15 to 45% by weight of styrene monomer units; b) 30 to 60% by weight of ethylenically unsaturated sulfonic acid monomer units in unneutralized, partially neutralized, or fully neutralized form, and c) providing a polymeric dispersant comprising a random copolymer comprising or consisting of 0 to 40% by weight of ethylenically unsaturated monomer units other than monomer units a) and b);

[0019] The monomer units a) in the random copolymer, i.e., the styrenic monomer units, may be derived from one or more styrenic monomers selected from styrene, C1-C4-alkyl-substituted styrenes, and combinations thereof. Suitable styrenic monomers include, but are not limited to, in particular, styrene, α-methylstyrene, α-ethylstyrene, vinyl toluenes such as 2-methylstyrene, 3-methylstyrene, and para-methylstyrene, 2,4-dimethylstyrene, 2,5-dimethylstyrene, para,α-dimethylstyrene, 2-ethylstyrene, 3-ethylstyrene, 4-ethylstyrene, 2-isopropylstyrene, 3-isopropylstyrene, 4-isopropylstyrene, para-tert-butylstyrene, and any combinations thereof. Preferably, the styrenic monomer units are derived from styrene, α-methylstyrene, or combinations thereof.

[0020] The monomer units a) preferably account for 20 to 45% by weight, more preferably 25 to 43% by weight, of the random copolymer.

[0021] Monomer unit b) in the random copolymer, i.e., ethylenically unsaturated sulfonic acid monomer unit, can be derived from one or more ethylenically unsaturated monomers containing sulfonic acid groups, which can be unneutralized, partially neutralized or fully neutralized.Examples of ethylenically unsaturated monomers containing sulfonic acid groups include, but are not limited to, vinyl compounds containing sulfonic acid groups, allyl compounds containing sulfonic acid groups, styrene compounds containing sulfonic acid groups, acrylic compounds containing sulfonic acid groups, and any combination thereof, which can be unneutralized, partially neutralized or fully neutralized.

[0022] It will be apparent that, as stated within the context of an ethylenically unsaturated sulfonic acid monomer unit or corresponding monomer, the "unneutralized," "partially neutralized," and "fully neutralized" forms mean that the sulfonic acid groups therein are present only in the free acid form, in a hybrid free acid / salt form, and only in the salt form, respectively.

[0023] Mention may especially be made of metal salts or quaternary ammonium salts in the partially or completely neutralized form of the ethylenically unsaturated sulfonic acid monomer units or of the corresponding monomers.

[0024] Preferably, the ethylenically unsaturated sulfonic acid monomer unit is of formula (I): [ka] (In the formula, R1 is hydrogen, methyl or ethyl; R2 is a linear or branched C1-C8 alkylene group), a salt of the acrylic sulfonic acid compound of formula (I), or a combination thereof.

[0025] In some embodiments, the ethylenically unsaturated sulfonic acid monomer unit is R 1 is hydrogen or methyl, and R2 is a linear or branched C3-C5 alkylene group, or a salt thereof, or a combination thereof. 1 is hydrogen and R2 is a straight or branched C4-alkylene group. Most preferably, the ethylenically unsaturated sulfonic acid monomer units are derived from 2-acrylamido-2-methylpropanesulfonic acid, a salt thereof, or a combination thereof.

[0026] The salt of the acrylic sulfonic acid compound having formula (I) may be a metal salt or a quaternary ammonium salt. In particular, mention may be made of alkali metal salts, such as sodium salts and potassium salts, and quaternary ammonium salts.

[0027] The monomer units b) preferably account for 40 to 57% by weight of the random copolymer, more preferably 45 to 55% by weight.

[0028] Within the context of the present invention, the amount of monomer unit (b) in the random copolymer is expressed as the unneutralized form of monomer unit (b). It will be understood that the amount of monomer unit (b) in the partially neutralized or fully neutralized form can be converted into the corresponding amount of the unneutralized form by calculation.

[0029] The random copolymers may optionally, and preferably do, comprise monomer units c), ie ethylenically unsaturated monomer units other than the monomer units a) and b) described herein.

[0030] Suitable monomer units c), hereinafter also referred to as ethylenically unsaturated monomer units c), may be derived from one or more monomers selected from ethylenically unsaturated carboxylic acids, or their salts, esters, amides or anhydrides, or any combination thereof.

[0031] Examples of suitable ethylenically unsaturated carboxylic acids include, but are not limited to, acrylic acid, methacrylic acid, ethacrylic acid, α-chloroacrylic acid, β-methylacrylic acid (crotonic acid), α-phenylacrylic acid, β-acryloxypropionic acid, sorbic acid, cinnamic acid, β-stearylacrylic acid, itaconic acid, citraconic acid, mesaconic acid, glutaconic acid, aconitic acid, maleic acid, and fumaric acid, of which acrylic acid and methacrylic acid are preferred.

[0032] Examples of suitable salts of ethylenically unsaturated carboxylic acids include, but are not limited to, alkali metal salts such as sodium salts and potassium salts, or quaternary ammonium salts of the above ethylenically unsaturated carboxylic acids. Metal salts of acrylic acid and methacrylic acid, particularly alkali metal salts such as sodium salts and potassium salts, are preferred.

[0033] Examples of suitable esters of ethylenically unsaturated carboxylic acids include, but are not limited to, C1-C4-alkyl esters, C1-C4-hydroxyl alkyl esters, and polyglycol esters of the above ethylenically unsaturated carboxylic acids, in particular C1-C4-alkyl acrylates, C1-C4-alkyl methacrylates, C1-C4-hydroxyl alkyl acrylates, C1-C4-hydroxyl alkyl methacrylates, polyethylene glycol acrylates, and polyethylene glycol methacrylates.

[0034] Examples of suitable amides of ethylenically unsaturated carboxylic acids include, but are not limited to, N-(C1-C4-alkyl)amides and N,N-di(C1-C4-alkyl)amides of the above ethylenically unsaturated carboxylic acids, in particular N-(C1-C4-alkyl)acrylamides, N-(C1-C4-alkyl)methacrylamides, N,N-di(C1-C4-alkyl)acrylamides, and N,N-di(C1-C4-alkyl)methacrylamides.

[0035] Examples of suitable anhydrides of ethylenically unsaturated carboxylic acids include, but are not limited to, the anhydrides of the above ethylenically unsaturated carboxylic acids, particularly succinic anhydride, maleic anhydride, itaconic anhydride, and citraconic anhydride.

[0036] Suitable ethylenically unsaturated monomer units c) can also be derived from vinyl monomers such as vinyl acetate and vinylpyrrolidone.

[0037] Preferably, the random copolymer comprises ethylenically unsaturated monomer units c) derived from one or more monomers selected from acrylic acid, methacrylic acid, metal salts of acrylic acid, metal salts of methacrylic acid, maleic anhydride, vinyl acetate, vinylpyrrolidone, or any combination thereof.

[0038] More preferably, the random copolymer comprises ethylenically unsaturated monomer units c) derived from one or more monomers selected from acrylic acid, methacrylic acid, alkali metal salts of acrylic acid, alkali metal salts of methacrylic acid, or any combination thereof.

[0039] The ethylenically unsaturated monomer units c) preferably constitute from 5 to 40% by weight of the random copolymer, more preferably from 10 to 30% by weight, most preferably from 10 to 20% by weight.

[0040] In some particular embodiments, the polymeric dispersant is a) 15 to 45% by weight of styrenic monomer units derived from one or more monomers selected from styrene, C1 to C4-alkyl substituted styrenes, or any combination thereof; b) 30 to 60% by weight of a compound of formula (I) [ka] (In the formula, R 1 is hydrogen or methyl, and R2 is a linear or branched C3-C5-alkylene), a salt of the acrylic sulfonic acid compound of formula (I), or an ethylenically unsaturated sulfonic acid monomer unit derived from one or more monomers selected from the following combinations: and c) 5 to 40% by weight of a random copolymer comprising, or preferably consisting of, ethylenically unsaturated monomer units derived from one or more monomers selected from acrylic acid, methacrylic acid, metal salts of acrylic acid, metal salts of methacrylic acid, maleic anhydride, vinyl acetate, vinylpyrrolidone, or any combination thereof.

[0041] In some other particular embodiments, the polymeric dispersant is a) 15 to 45 weight percent styrenic monomer units derived from one or more monomers selected from styrene, α-methylstyrene, or a combination thereof; b) 30 to 60% by weight of a compound of formula (I) [ka] (In the formula, R 1 is hydrogen, and R2 is a linear or branched C4-alkylene group), a salt of the acrylic sulfonic acid compound of formula (I), or a combination thereof; and, c) A random copolymer comprising, or preferably consisting of, 5 to 40% by weight of ethylenically unsaturated monomer units derived from one or more monomers selected from acrylic acid, methacrylic acid, an alkali metal salt of acrylic acid, an alkali metal salt of methacrylic acid, or any combination thereof.

[0042] In these particular embodiments, the random copolymer preferably comprises or consists of 20-45% by weight of monomer units a), 40-57% by weight of monomer units b), and 10-30% by weight of monomer units c).

[0043] More preferably, the random copolymer comprises or consists of 25-43% by weight of monomer units a), 45-55% by weight of monomer units b), and 10-20% by weight of monomer units c).

[0044] The random copolymer has a weight average molecular weight (M) of 3,000 to 100,000 g / mol, preferably 7,000 to 60,000 g / mol, preferably 10,000 to 40,000 g / mol, more preferably 12,000 to 35,000 g / mol, as measured by GPC. w ).

[0045] Random copolymers typically have a polydispersity (PDI) in the range of 3-10, as measured by GPC.

[0046] The polymeric dispersant according to the present invention may comprise the random copolymer described herein as the only active substance, in other words, the polymeric dispersant according to the present invention may or may not comprise any other substance having dispersing ability.

[0047] The polymeric dispersion may be in the form of an aqueous solution containing the random copolymer. In this case, water is present in the polymeric dispersion as a solvent or medium for the random copolymer. Optionally, the polymeric dispersion further comprises an organic solvent, which may, for example, result from the preparation of the polymer. Preferably, the organic solvent is a high molecular weight compound, such as a polyether alcohol, an alkyl polyether alcohol, such as polyethylene glycol or an alkyl-terminated polyethylene glycol.

[0048] The solids concentration of the aqueous solution is not particularly limited, but may be 25 to 70% by weight, preferably 30 to 60% by weight, based on the total weight of the aqueous solution.

[0049] The polymeric dispersant, when present as an aqueous solution containing the random copolymer, may have a pH in the range of 4.0 to 5.5, preferably about 5.

[0050] The polymeric dispersant may also contain any of the auxiliaries resulting from the preparation of the random copolymer, such as initiators, polymerization modifiers, pH modifiers, surfactants, and the like.

[0051] The random copolymer can be prepared by radical polymerization of the monomers to derive the above monomer units a), b) and c) under homogeneous conditions.To prepare the random copolymer, any known process of homogeneous radical polymerization can be applied without particular limitation.

[0052] The radical polymerization is preferably carried out in water, optionally in an organic solvent. Preferably, any volatile organic solvent, if used in the radical polymerization, is removed after the polymerization is completed.

[0053] The polymeric dispersant may be the polymerization product obtained directly from the radical polymerization, or may be produced after processing the polymerization product obtained directly from the radical polymerization, for example after removing any volatile organic solvent, after dilution with water, or after removing any volatile organic solvent and then dilution with water.

[0054] In a second aspect, the present invention provides a method for producing a pharmaceutical composition comprising the steps of: i) a disperse dye; ii) A random copolymer comprising the following monomer units: a) 15 to 45% by weight of styrene monomer units; b) 30 to 60% by weight of ethylenically unsaturated sulfonic acid monomer units in unneutralized, partially neutralized, or fully neutralized form, and c) a random copolymer comprising or consisting of 0 to 40% by weight of ethylenically unsaturated monomer units other than the monomer units a) and b); iii) water An aqueous disperse dye composition comprising: In this case, the random copolymer and the disperse dye are present in a weight ratio ranging from 1:50 to 1:3.

[0055] The disperse dyes are preferably selected from monoazo dyes, disazo dyes, anthraquinone dyes, or any combination thereof.

[0056] In particular, the disperse dye may be selected from CI disperse orange 288, CI disperse orange 30, CI disperse red 167, CI disperse blue 291, CI disperse blue 79, CI disperse violet 93, and any combination thereof.

[0057] In the aqueous disperse dye composition, the disperse dye has a D in the range of 0.5 to 1.5 microns, preferably 0.5 to 1.0 microns, as measured by laser diffraction. 50Preferably, the particles of the disperse dye have a D value of 3.0 microns or less, preferably 2.0 microns or less, as measured by laser diffraction. 90 It has a value.

[0058] The disperse dye may be present in the aqueous disperse dye composition in an amount of from 20 to 40% by weight, preferably from 25 to 35% by weight, based on the total weight of the aqueous disperse dye composition.

[0059] The random copolymers may be the same as those included in the polymeric dispersants according to the invention. Any general explanations and preferences given above for random copolymers within the context of polymeric dispersants are applicable here by reference.

[0060] The random copolymer may be present in the aqueous disperse dye composition in an amount of from 0.3 to 10% by weight, preferably from 1 to 8% by weight, and more preferably from 1.5 to 5% by weight, based on the total weight of the aqueous disperse dye composition.

[0061] In particular, the random copolymer and the disperse dye are present in the aqueous disperse dye composition in a weight ratio ranging from 1:30 to 1:5, preferably from 1:30 to 1:6, and more preferably from 1:20 to 1:7.

[0062] The aqueous disperse dye composition may further include one or more additives that are typically added to liquid forms of disperse dyes, such as preservatives, antioxidants, defoamers, viscosity modifiers, and surfactants, in addition to the random copolymers described herein.In addition, the aqueous disperse dye composition may include components derived from the preparation of the random copolymer, such as non-volatile organic solvents and / or auxiliaries such as initiators, polymerization regulators, pH adjusters, and surfactants.

[0063] If any additives and / or components derived from the preparation of the random copolymer are present in the aqueous disperse dye composition, their total amount will be up to 5% by weight, preferably up to 1% by weight, based on the weight of the aqueous disperse dye composition.

[0064] Water is present in the aqueous disperse dye composition in an amount of 50 to 75% by weight, preferably 60 to 70% by weight, based on the total weight of the aqueous disperse dye composition.

[0065] The aqueous disperse dye composition typically has a pH in the range of from 4 to 6.5, preferably from 4.5 to 6.

[0066] In some exemplary embodiments, the present invention provides a method for producing a disperse dye comprising the steps of: i) 20 to 40% by weight of a disperse dye; ii) 0.3 to 10 wt. % of a random copolymer as described herein; iii) 50 to 75% by weight of water; An aqueous disperse dye composition comprising: In this case, the random copolymer and the disperse dye are present in the aqueous disperse dye composition in a weight ratio ranging from 1:50 to 1:3.

[0067] In a further exemplary embodiment, the present invention provides a method for preparing a disperse dye comprising the steps of: i) 25 to 35% by weight of a disperse dye; ii) 1 to 8 wt. % of a random copolymer as described herein; iii) 60 to 70% by weight of water; An aqueous disperse dye composition comprising: In this case, the random copolymer and the disperse dye are present in the aqueous disperse dye composition in a weight ratio ranging from 1:30 to 1:5, preferably from 1:30 to 1:6.

[0068] In some other exemplary embodiments, the present invention provides a composition comprising, based on the total weight of the aqueous disperse dye composition: i) 25 to 35% by weight of a disperse dye; ii) 1.5 to 5 wt. % of a random copolymer as described herein; iii) 60 to 70% by weight of water; An aqueous disperse dye composition comprising: In this case, the random copolymer and the disperse dye are present in the aqueous disperse dye composition in a weight ratio ranging from 1:20 to 1:7.

[0069] In the above exemplary embodiment, the random copolymer comprises the following monomer units: a) 15 to 45% by weight of styrene monomer units; b) 30 to 60% by weight of ethylenically unsaturated sulfonic acid monomer units in unneutralized, partially neutralized, or fully neutralized form, and c) containing, or preferably consisting of, 5 to 40% by weight of ethylenically unsaturated monomer units other than the monomer units a) and b).

[0070] In the above exemplary embodiment, the random copolymer preferably comprises, or preferably consists of, 20-45 wt. % of styrenic monomer units a), 40-57 wt. % of monomer units b), and 10-30 wt. % of monomer units c).

[0071] In the above exemplary embodiment, the random copolymer preferably comprises, or preferably consists of, 25-43 wt. % of monomer units a), 45-55 wt. % of monomer units b), and 10-20 wt. % of monomer units c).

[0072] In a third aspect, the present invention provides a process for producing an aqueous disperse dye composition comprising grinding in water one or more presscakes of a disperse dye in the presence of a polymeric dispersant as defined in the first aspect of the present invention.

[0073] The polymeric dispersant is used in an amount such that the weight ratio of random copolymer to disperse dye is in the range of 1:50 to 1:3, particularly 1:30 to 1:5, preferably 1:30 to 1:6, more preferably 1:20 to 1:7.

[0074] The grinding can be carried out in the presence of one or more additives typically used in liquid forms of disperse dyes, such as preservatives, antioxidants, defoamers, viscosity modifiers, and surfactants, in addition to the random copolymers described herein.

[0075] It will be apparent that the grinding can be carried out by any technical means known in the art, so long as the aqueous disperse dye composition according to the second aspect of the present invention can be obtained.

[0076] The present invention is further described by the following examples which set forth particularly advantageous embodiments. The examples are provided to illustrate the invention and are not intended to limit it. EXAMPLES

[0077] I. Description of Materials and Measurements material: PEG solvent: Polyethylene glycol monomethyl ether, Mn=500, from BASF; Defoamer: Modified polydimethylsiloxane defoamer from BASF. AMPS-Na: 2-acrylamido-2-methylpropanesulfonic acid sodium salt, 50% aqueous solution, from All-Plus Chemicals. TBPEH: tert-butyl peroxy-2-ethylhexanoate, from Adamas-beta; Acrylic acid (AA), styrene, n-butanol, isopropanol, 95 zirconia beads, sodium metabisulfite and sodium persulfate (NaPS): from Sinopharm Chemical Reagents. Mercaptoethanol (ME): from TCI, MF: Methylnaphthalenesulfonic acid formaldehyde condensate, from Zhejiang Wulong New Materials Co. Ltd. Disperse Blue 79 and Disperse Red 167: From Anoky, Disperse Orange 288, Disperse Blue 291, Disperse Violet 93: From Zhejiang Longsheng Group Co., Ltd.

[0078] measurement: 1)Molecular weight The molecular weight was measured by aqueous phase GPC test. The sample was dissolved at 1.5 mg / mL in the eluent at room temperature for 2 hours and filtered through a 0.45 μm membrane before injection. The test was carried out according to the following settings and conditions: Column: TSKgel GMPWXL 13μm×2,300×7.8mm Column temperature: 35℃ Eluent: H2O + 0.01M phosphate buffer + 0.1M NaCl, pH = 7.4 Flow rate: 0.8mL / min Injection volume: 100uL Detection: Refractive index

[0079] The aqueous phase standard curve was calibrated with solutions of narrow polydispersity polyacrylic acid with molecular weights ranging from 1,250 to 1,100,000, also run under the conditions described above.

[0080] 2) Particle size Particle size, D 50 and D. 90 was measured by a laser diffraction instrument Malvern Mastersizer 3000 in general mode with the absorption coefficient set to 1.

[0081] 3) Composition of random copolymers The composition of the copolymer is 1 The conversion of all monomers in the polymerization process was more than 99%, as confirmed by H-NMR spectrum.

[0082] II. Preparation of polymeric dispersants Example 1 370.15g PEG solvent, 12.45g AA and 79.23g AMPS-Na were initially placed in a 2L glass reactor and heated to 95°C under N2 purging and stirring. Then 180g styrene, a solution of 112.07g AA and 713.12g AMPS-Na (AA / AMPS-Na solution), a solution of 42.04g NaPS in 126.13g water (NaPS solution), and a solution of 42.04g sodium metabisulfite in 126.13g water (sodium metabisulfite solution) were simultaneously and separately fed into the reactor. Styrene was fed over 120 minutes, AA / AMPS-Na solution was fed over 90 minutes, NaPS solution was fed over 240 minutes, and sodium metabisulfite solution was fed over 210 minutes. After the feeds were completed, the polymerization was continued for 120 minutes, then cooled to 40° C. and diluted to 50% solids with deionized water.

[0083] The weight average molecular weight (M w ) has a molecular weight of 30,300 g / mol and a polydispersity index (PDI) of 5.3.

[0084] This copolymer is composed of about 27% by weight of monomer units derived from styrene, about 54% by weight of monomer units derived from 2-acrylamido-2-methylpropanesulfonic acid, sodium salt (represented as AMPS), and about 19% by weight of monomer units derived from acrylic acid.

[0085] Examples 2 to 5 329.34g of PEG solvent was initially placed in a 2L glass reactor and heated to 95°C under N2 purging and stirring. Then 180g of styrene, a solution of 124.54g of AA and 792.38g of AMPS-Na (AA / AMPS-Na solution), a solution of 21.02g of TBPEH in 21.02g of PEG solvent (TBPEH solution), and a certain amount of mercaptoethanol (ME) were fed simultaneously and separately into the reactor. Styrene was fed over 120 minutes, AA / AMPS-Na solution was fed over 90 minutes, TBPEH solution was fed over 150 minutes, and ME was fed over 120 minutes. After the feeding was completed, the polymerization was continued for 180 minutes, then cooled to 40°C and diluted with deionized water to 50% solids. The dosage of ME and the properties of the copolymer in each example are shown in the following table:

[0086] [Table 1]

[0087] Each copolymer is comprised of about 27% by weight monomer units from styrene, about 54% by weight monomer units from 2-acrylamido-2-methylpropanesulfonic acid, sodium salt (represented as AMPS), and about 19% by weight monomer units from acrylic acid.

[0088] Example 6 261.96g of n-butanol was initially charged into a 2L glass reactor and heated to 95°C under N2 purging and stirring. 180g of styrene, a solution of 124.54g of AA and 792.38g of AMPS-Na (AA / AMPS-Na solution), a solution of 21.02g of TBPEH in 88.40g of n-butanol (TBPEH solution), and 21.02g of ME were simultaneously and separately fed into the reactor. Styrene was fed over 120 minutes, AA / AMPS-Na solution was fed over 90 minutes, TBPEH solution was fed over 150 minutes, and ME was fed over 120 minutes. After the end of the feed, the polymerization was continued for 180 minutes, and then subjected to steam distillation to remove all of the n-butanol, and an aqueous polymer solution with a solid content of 50% was obtained.

[0089] The weight average molecular weight (M w ) is 7,650 g / mol and the polydispersity index (PDI) is 3.4.

[0090] This copolymer is composed of about 27% by weight of monomer units derived from styrene, about 54% by weight of monomer units derived from 2-acrylamido-2-methylpropanesulfonic acid, sodium salt (represented as AMPS), and about 19% by weight of monomer units derived from acrylic acid.

[0091] Examples 7 to 10 344.95g of PEG solvent was initially placed in a 2L glass reactor and heated to 95°C under N2 purging and stirring. 300g of styrene, a solution of 103.79g of AA and 660.29g of AMPS-Na (AA / AMPS-Na solution), a solution of 22.01g of TBPEH in 22.01g of PEG solvent (TBPEH solution), and a certain amount of mercaptoethanol (ME) were fed simultaneously and separately into the reactor. Styrene was fed over 120 minutes, AA / AMPS-Na solution was fed over 90 minutes, TBPEH solution was fed over 180 minutes, and ME was fed over 150 minutes. After the end of the feeds, the polymerization was continued for 180 minutes, then cooled to 40°C and diluted with deionized water to 50% solids. The dosage of ME and the properties of the copolymer in each example are shown in the following table:

[0092] [Table 2]

[0093] Each copolymer is comprised of about 43% by weight monomer units from styrene, about 42% by weight monomer units from 2-acrylamido-2-methylpropanesulfonic acid, sodium salt (represented as AMPS), and about 15% by weight monomer units from acrylic acid.

[0094] Example 11 370.15g PEG solvent, 12.45g AA and 79.23g AMPS-Na were initially charged into a 2L glass reactor and heated to 95°C under N2 purge and stirring. 180g styrene, a solution of 112.07g AA and 713.12g AMPS-Na (AA / AMPS-Na solution), a solution of 42.04g NaPS in 126.13g water (NaPS solution), and 42.04g ME were simultaneously and separately fed into the reactor. Styrene was fed over 120 minutes, AA / AMPS-Na solution was fed over 90 minutes, NaPS solution was fed over 240 minutes, and ME was fed over 210 minutes. After the end of the feeds, the polymerization was continued for 120 minutes, then cooled to 40°C and diluted to 50% solids with deionized water.

[0095] The weight average molecular weight (M w ) is 3,720 g / mol and the polydispersity index (PDI) is 2.5.

[0096] This copolymer is composed of about 27% by weight of monomer units derived from styrene, about 54% by weight of monomer units derived from 2-acrylamido-2-methylpropanesulfonic acid, sodium salt (represented as AMPS), and about 19% by weight of monomer units derived from acrylic acid.

[0097] Example 12 344.95g of PEG solvent was initially placed in a 2L glass reactor and heated to 95°C under N2 purge and stirring. 300g of styrene, a solution of 103.79g of AA and 660.29g of AMPS-Na (AA / AMPS-Na solution), a solution of 22.01g of TBPEH in 22.01g of PEG solvent (TBPEH solution), and 44.03g of ME were fed simultaneously and separately into the reactor. Styrene was fed over 120 minutes, AA / AMPS-Na solution was fed over 90 minutes, TBPEH solution was fed over 180 minutes, and ME was fed over 150 minutes. After the end of the feeds, the polymerization was continued for 180 minutes, then cooled to 40°C and diluted to 50% solids with deionized water.

[0098] The weight average molecular weight (M w) is 3,280 g / mol and the polydispersity index (PDI) is 2.5.

[0099] This copolymer is composed of about 43% by weight of monomer units derived from styrene, about 42% by weight of monomer units derived from 2-acrylamido-2-methylpropanesulfonic acid, sodium salt (represented as AMPS), and about 15% by weight of monomer units derived from acrylic acid.

[0100] Comparative Example 13 184.64g of PEG solvent was initially placed in a 2L glass reactor and heated to 95°C under N2 purge and stirring. 200g of styrene, a solution of 46.13g of AA and 293.46g of AMPS-Na (AA / AMPS-Na solution), a solution of 11.79g of TBPEH in 11.79g of PEG solvent (TBPEH solution), and 3.54g of ME were simultaneously and separately fed into the reactor. Styrene was fed over 90 minutes, AA / AMPS-Na solution was fed over 100 minutes, TBPEH solution was fed over 180 minutes, and ME was fed over 150 minutes. After the end of the feeds, the polymerization was continued for 180 minutes, then cooled to 40°C and diluted to 50% solids with deionized water.

[0101] The weight average molecular weight (M w ) has a molecular weight of 35,200 g / mol and a polydispersity index (PDI) of 5.2.

[0102] This copolymer is composed of about 53% by weight of monomer units derived from styrene, about 35% by weight of monomer units derived from 2-acrylamido-2-methylpropanesulfonic acid, sodium salt (represented as AMPS), and about 12% by weight of monomer units derived from acrylic acid.

[0103] Comparative Example 14 159.46g PEG solvent, 6.92g AA and 44.02g AMPS-Na were initially placed in a 2L glass reactor and heated to 95°C under N2 purge and stirring. 50g styrene, a solution of 62.27g AA and 396.17g AMPS-Na (AA / AMPS-Na solution), a solution of 10.18g TBPEH in 10.18g PEG solvent (TBPEH solution), and 3.05g ME were simultaneously and separately fed into the reactor. Styrene was fed over 150 minutes, AA / AMPS-Na solution was fed over 90 minutes, TBPEH solution was fed over 180 minutes, and ME was fed over 150 minutes. After the end of the feeds, the polymerization was continued for 120 minutes, then cooled to 40°C and diluted to 50% solids with deionized water.

[0104] The weight average molecular weight (M w ) has a molecular weight of 37,300 g / mol and a polydispersity index (PDI) of 5.5.

[0105] This copolymer is composed of about 17% by weight of monomer units derived from styrene, about 62% by weight of monomer units derived from 2-acrylamido-2-methylpropanesulfonic acid, sodium salt (represented as AMPS), and about 21% by weight of monomer units derived from acrylic acid.

[0106] III. Application Test General procedure for preparation of disperse dyes in liquid form Liquid form disperse dye samples were prepared by grinding the dye press cake in the presence of the polymeric dispersant obtained from each preparation example in a PMQW2 Omnibearing Planetary Ball Mill from Nanjing Chi Shun Technology Development Co., Ltd. The general formulation of liquid form disperse dyes is summarized in the table below.

[0107] [Table 3]

[0108] The grinding was carried out using 70 parts by weight of 95 zirconia beads for 100 parts by weight of the liquid form of the disperse dye formulation. During grinding, some additional steel balls (2 x 20 mm diameter balls and 20 x 10 mm diameter balls) were added. The grinding conditions were set at 200 rpm for 12 hours.

[0109] Storage performance evaluation The prepared liquid disperse dye samples were stored at room temperature unless otherwise specified and were periodically inspected. The storage performance was evaluated for settling and flowability according to the criteria given in the table below.

[0110] [Table 4]

[0111] Application Test 1 Disperse dye samples in liquid form in black were prepared using various dispersants according to the general procedure above, except that the amount of dispersant was 3.0% by weight and the amount of dye was 28.0% by weight, calculated as solids. A mixture of Disperse Orange 288, Disperse Blue 291, and Disperse Violet 93 in a weight ratio of 12.5:8:7.5 was used to give the black color. The results are summarized in Table 1.

[0112] [Table 5]

[0113] In comparison with the conventional dispersant MF, it can be seen that the inventive dispersants (Examples 1-11) comprising the random copolymer according to the invention provide better flowability and storage stability for disperse dyes in liquid form, whereas the comparative dispersants do not.

[0114] Application Test 2 A black liquid form disperse dye sample was prepared by the same process as described in Application Test 1, except that a smaller amount of dispersant was used. The results are summarized in Table 2.

[0115] [Table 6]

[0116] The results in Table 2 show that the dispersants of Examples 1, 4, and 5 are capable of providing free-flowing compositions without settling for over four weeks at reduced dosages.

[0117] Application Test 3 Disperse dye samples in liquid form of various colours were prepared according to the general procedure described above, except that the amount of dye in each case, calculated as solids, was 30.0% by weight, and the amount of dispersant was 4.0% by weight for Disperse Red 167 and Disperse Blue 79, and 3.0% by weight for Disperse Blue 291, Disperse Violet 93, and Disperse Orange 288. The results are summarised in Table 3.

[0118] [Table 7]

[0119] The results in Table 3 show that the dispersants according to the present invention are applicable to dyes of various colors and provide better or at least equivalent flowability and storage stability for disperse dyes in liquid form compared to conventional dispersant MF.

Claims

1. The following monomer units: a) 15 to 45% by weight of styrene monomer units; b) 30 to 60% by weight of ethylenically unsaturated sulfonic acid monomer units in unneutralized, partially neutralized, or fully neutralized form; and c) A polymeric dispersant comprising a random copolymer comprising or consisting of 0 to 40% by weight of ethylenically unsaturated monomer units other than the monomer units a) and b).

2. The styrene-based monomer unit is styrene, C １ ~C ４ 10. The polymeric dispersant of claim 1, derived from one or more styrenic monomers selected from: - alkyl-substituted styrene;

3. 10. The polymeric dispersant of claim 1, wherein the ethylenically unsaturated sulfonic acid monomer units are derived from one or more ethylenically unsaturated monomers containing sulfonic acid groups that are unneutralized, partially neutralized, or fully neutralized.

4. 4. The polymeric dispersant of claim 3, wherein the ethylenically unsaturated monomer containing a sulfonic acid group is selected from a vinyl compound containing a sulfonic acid group, an allylic compound containing a sulfonic acid group, a styrenic compound containing a sulfonic acid group, an acrylic compound containing a sulfonic acid group, or any combination thereof, which is unneutralized, partially neutralized, or fully neutralized.

5. The ethylenically unsaturated monomer containing a sulfonic acid group is represented by the formula (I): 【Chemistry 1】 (In the formula, R １ is hydrogen, methyl or ethyl, R ２ is a straight or branched chain C １ ~C ８ -alkylene group), a salt of the acrylic sulfonic acid compound of formula (I), or a combination thereof.

6. R １ is hydrogen or methyl, preferably H, and R ２ is a straight or branched chain C ３ ~C ５ - an alkylene group, preferably C ４ 6. The polymeric dispersant of claim 5, wherein the alkylene group is -.

7. 2. The polymeric dispersant of claim 1, wherein said monomeric unit c) is derived from one or more monomers selected from ethylenically unsaturated carboxylic acids, or salts, esters, amides, or anhydrides thereof, vinyl monomers such as vinyl acetate and vinylpyrrolidone, or any combination thereof.

8. 8. The polymeric dispersant of claim 7, wherein said monomeric unit c) is derived from one or more monomers selected from acrylic acid, methacrylic acid, metal salts of acrylic acid, metal salts of methacrylic acid, maleic anhydride, vinyl acetate, vinylpyrrolidone, or any combination thereof.

9. 2. The polymeric dispersant of claim 1, wherein the monomeric unit a) comprises 20 to 45% by weight of the random copolymer, preferably 25 to 43% by weight.

10. 2. The polymeric dispersant of claim 1, wherein the monomer unit b) comprises 40 to 57% by weight of the random copolymer, preferably 45 to 55% by weight.

11. 2. The polymeric dispersant of claim 1, wherein said monomeric unit c) comprises 5 to 40% by weight of said random copolymer, preferably 10 to 30% by weight, more preferably 10 to 20% by weight.

12. 1. An aqueous disperse dye composition comprising: i) a disperse dye; ii) a random copolymer according to any one of claims 1 to 11; and iii) water, The aqueous disperse dye composition, wherein the random copolymer and the disperse dye are present in a weight ratio ranging from 1:50 to 1:

3.

13. 13. The aqueous disperse dye composition of claim 12, wherein the disperse dye is selected from a monoazo dye, a disazo dye, an anthraquinone dye, or any combination thereof.

14. 13. The aqueous disperse dye composition according to claim 12, wherein the disperse dye is present in an amount of 20 to 40% by weight, preferably 25 to 35% by weight, based on the total weight of the aqueous disperse dye composition.

15. 13. The aqueous disperse dye composition according to claim 12, wherein the random copolymer is present in an amount of 0.3 to 10% by weight, preferably 1 to 8% by weight, more preferably 1.5 to 5% by weight, based on the total weight of the aqueous disperse dye composition.

16. 13. The aqueous disperse dye composition of claim 12, wherein said random copolymer and said disperse dye are present in a weight ratio ranging from 1:30 to 1:5, preferably from 1:30 to 1:6, more preferably from 1:20 to 1:

7.

17. 12. A process for producing an aqueous disperse dye composition, comprising grinding one or more presscakes of disperse dyes in water in the presence of the polymeric dispersant of any one of claims 1 to 11.

18. 18. The process of claim 17, wherein the disperse dye is selected from a monoazo dye, a disazo dye, an anthraquinone dye, or any combination thereof.

19. 18. A process according to claim 17, wherein the polymeric dispersant is used in an amount such that the weight ratio of the random copolymer to the disperse dye ranges from 1:50 to 1:3, in particular from 1:30 to 1:5, preferably from 1:30 to 1:6, more preferably from 1:20 to 1:7.

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