CN116917569A

CN116917569A - Formaldehyde-free aqueous composition for textile discharge printing

Info

Publication number: CN116917569A
Application number: CN202280017890.XA
Authority: CN
Inventors: 乔奎因·费马特·加拉米洛; 马克·萨巴特·里乌斯
Original assignee: Archroma IP GmbH
Current assignee: Archroma IP GmbH
Priority date: 2021-03-04
Filing date: 2022-03-03
Publication date: 2023-10-20
Also published as: EP4053331A1; EP4301921A1; JP2024510904A; BR112023017926A2; KR20230162591A; US20240060236A1; CO2023011700A2; WO2022184831A1

Abstract

The present invention relates to a composition for the discharge printing of fabrics, a discharge printing process for printing said composition onto fabrics, the use of the composition for discharge printing and fabrics treated with the composition in the discharge printing process according to the invention.

Description

Formaldehyde-free aqueous composition for textile discharge printing

Technical Field

The present invention relates to formaldehyde-free aqueous compositions for discharge printing of dyed fabrics, to their use and method of manufacture, and to a discharge printing process.

Background

Discharge printing involves a special printing process for bleached (white) or colored fabrics. The key element in discharge printing is a discharge printing composition comprising a reducing agent. Discharge printing begins with colored fabrics colored with dyes. The dye is sensitive to reducing agents and degrades when treated with a discharge printing composition comprising a reducing agent. The discharge printing composition is printed onto the fabric and the dye of the fabric is discharged in the printed pattern area. It is thus possible to produce a white pattern of discharge fabric in which the natural color of the fabric becomes visible. In other applications, the printing composition further comprises a reducing agent resistant pigment. A coloured discharge fabric is thus obtained in which the bleached print is covered with the colour of the reducing agent resistant pigment. Commonly known reducing agents for discharge printing are Rongalit ST liquid and/or Rongalit C powder (both based on sodium formaldehyde sulfoxylate derivatives). Printing compositions for discharge printing generally comprise other components, such as thickeners, binders and auxiliaries, such as softeners, emulsifiers, crosslinking agents, rheology modifiers, etc., and pigment preparations.

The known discharge printing processes require steaming and curing process steps after the printing step to destroy the discharged dye and the formaldehyde reducing agent containing residues. Other process steps are involved in the discharge printing process, including a fixing process step for fixing the binder and a final washing step to eliminate all chemical residues including formaldehyde.

A problem with existing systems and methods is that consumers often complain of formaldehyde odor during drying, steaming and fixing when using ordinary discharge printing compositions and methods. In addition, brand manufacturers are seeking more environmentally friendly sustainable systems and methods that do not release formaldehyde. Thus, discharge printing methods have been developed that avoid the steaming step. These processes are known as dry discharge printing. However, the reducing agents used in these processes still use zinc formaldehyde sulfoxylate derivatives. These reducing agents are characterized by their high reducing action, which also affects the undesired degradation of the thickening agents that must be used in the printing paste composition. As a result, the viscosity of the printing paste often tends to be out of specification, which is disadvantageous in industrial discharge printing processes. To overcome these disadvantages, alternative thickeners are used to counteract the reduction of zinc formaldehyde sulfoxylate derivatives. However, these thickeners require more complex printing compositions and costs.

OBJECT OF THE INVENTION

It is therefore an object of the present invention to provide a composition which avoids the use of formaldehyde-containing reducing agents for the discharge printing of textiles, reduces complexity and process time, and maintains the stability of the printing paste during printing, further improving the printing quality of discharge printed textiles.

Disclosure of Invention

This object is solved by the following items:

item 1: a formaldehyde-free aqueous composition for textile discharge printing, wherein the composition comprises at least one reducing agent, at least one synthetic thickener, at least one wetting agent, at least one pH adjusting agent, optionally at least one pigment, and optionally at least one binder.

Item 2: the composition of item 1, wherein the at least one synthetic thickener is a polyacrylic acid compound, preferably selected from acrylic acid copolymers, preferably comprising a high density oil and an adjuvant.

Item 3: the composition of at least one of items 1 or 2, wherein the at least one binder is based on a copolymer of two or more of poly (butyl acrylate), butyl (acrylate), ethyl (acrylate), and styrene, a polyethylene acrylate, acrylonitrile, or a mixture thereof.

Item 4: the composition of at least one of items 1 to 3, wherein the wetting agent is selected from urea, glycerol, or mixtures thereof.

Item 5: the composition of at least one of clauses 1 to 4, wherein the reducing agent comprises or consists of a sulfinic acid derivative.

Item 6: the composition of at least one of items 1 to 5, further comprising one or more components selected from the group consisting of: a cross-linking agent, a softening agent, an emulsifying agent, a defoamer, a rheology modifier and an oxidation protectant or a mixture thereof.

Item 7: the composition of at least one of clauses 1 to 6, wherein the composition is free of any natural thickening agent.

Item 8: the composition of at least one of clauses 1 to 7, wherein the composition comprises 3 to 30 weight percent of at least one reducing agent, 0.05 to 6 weight percent of at least one synthetic thickener, 3 to 45 weight percent of at least one wetting agent, 0.05 to 4 weight percent of at least one pH adjusting agent, 0 to 30 weight percent of at least one binder, 0 to 2 weight percent of at least one emulsifying agent, 0 to 1 weight percent of at least one defoamer, 0 to 3 weight percent of at least one crosslinking agent, 0 to 3 weight percent of at least one softening agent, 0 to 2 weight percent of at least one rheology modifying agent, 0 to 2 weight percent of at least one oxidation protecting agent, 0 to 6 weight percent of at least one pigment dispersion, and the balance being water, wherein weight percent is based on the total weight of the composition.

Item 9: a method of manufacturing a composition according to at least one of items 1 to 8, comprising the following step a and optionally steps B and C: step A: mixing and homogenizing all components of the composition according to at least one of items 1 to 8, except for at least one pigment, in the presence of at least one pigment in the composition according to at least one of items 1 to 8; and (B) step (B): adding at least one dispersion comprising at least one pigment to the mixture obtained in step a, step C: the mixture obtained in step B is mixed and homogenized.

Item 10: use of the formaldehyde-free aqueous composition according to at least one of items 1 to 8, or of the formaldehyde-free aqueous composition manufactured according to the method defined in item 9, for a discharge printing process, in particular for a white discharge or color discharge printing process of a fabric.

Item 11: a discharge printing process for printing a fabric, the process comprising the steps of: step 1: providing a colored fabric, step 2: and (3) printing: printing a fabric with the formaldehyde-free aqueous composition according to at least one of items 1 to 8, or manufactured according to the method defined in item 9, step 3: a first drying step: drying the fabric obtained in the step 2, and step 4: washing: washing the fabric obtained in step 3, wherein the fabric is rinsed with a rinsing liquid and/or soaped with a soaping liquid, step 5: and a second drying step: the fabric obtained in step 4 is dried.

Item 12: the method of item 11, wherein the washing step comprises a first cold rinsing and/or hot rinsing step, wherein the washing step is performed with a water source selected from cold water or H ₂ O ₂ A rinsing liquid of an aqueous solution to rinse the printed fabric, and/or a hot soaping step, wherein the printed fabric is washed with a soaping liquid selected from soapy water at a temperature of 40-80 ℃, and/or a second cold rinsing step, wherein the printed fabric is rinsed with a second rinsing liquid selected from cold water.

Item 13: the method according to at least one of items 11 or 12, wherein the first drying step is performed at a temperature of 140 ℃ to 180 ℃, preferably 1 to 5 minutes, and/or wherein the second drying step is performed at a temperature of 120 ℃ to 160 ℃, preferably 8 to 20 minutes.

Item 14: the method of at least one of items 11 to 13, wherein the method does not comprise a curing step and/or a steaming step.

Item 15: a fabric treated with the composition according to at least one of items 1 to 8 or the composition obtained according to item 9 in the discharge printing method according to at least one of items 11 to 14.

Detailed Description

In a first aspect, the object of the present invention is solved by a formaldehyde-free aqueous composition for textile discharge printing, wherein the composition comprises at least one reducing agent, at least one synthetic thickener, at least one wetting agent, at least one pH adjustor, optionally at least one pigment and optionally at least one binder.

The composition has the advantage of no formaldehyde. Thus, no formaldehyde is released during discharge printing using the composition according to the application. Thus eliminating the bad smell and harmful effect of formaldehyde. In the context of the present application, the term "formaldehyde-free" means that no formaldehyde residue can be detected when measured according to AATCC 112 according to commonly known measurement methods. Furthermore, the composition according to the application has the advantage of improving the printing quality of the discharge printing process.

The term "reducing agent" as used in the context of the present application refers to an agent capable of reducing a reactive dye. The at least one reducing agent present in the composition according to the application comprises or consists of a sulfinic acid derivative. The at least one reducing agent does not comprise any formaldehyde-releasing compound or moiety. It has been observed that fabrics can be effectively treated in a discharge printing process by the sulfinic acid derivatives. It has also been observed that the processing time and energy consumption of the discharge printing process employing the composition of the present application can be significantly reduced because there is no need to treat the discharge printed fabric in an additional curing step as in conventional discharge printing processes.

Another benefit of the composition according to the application is the simplicity of preparation. The preparation of the composition according to the application may be carried out in the consumer's facility. Due to the reducing strength of the at least one reducing agent, additional steaming steps commonly employed in known discharge printing methods can also be avoided. By using the composition according to the application, a discharge effect on the dye has been achieved with hot air. In addition, another benefit is that less detrimental effect on the colored pigment is observed with the composition according to the application. With this benefit, brighter shades can be obtained by the printing process.

In the context of the present application, the term "sulfinic acid derivative" refers to a reducing agent comprising or consisting of one or more sulfinic acid derivative compounds. For example, sulfinic acid derivatives of formula RSO (OX) can be used, wherein X represents equilibrium RSO (O) ^- And is selected from the group consisting of H, alkali metal cations,Wherein R is ¹ Representation H, C ₁ To C ₄ Alkyl or mixtures thereof; wherein R represents an alkyl group which may be further substitutedOr an aryl residue. Typical sulfinic acid derivatives used in the composition according to the application are under the trade name +. >ECO is sold.

In the discharge printing method, the reducing agent is required to have a certain oxidation-reduction potential in order to produce a bleaching discharge effect on the dye of the fabric. The term "redox potential" is known in the art. It describes the ability of a compound to transfer electrons to or accept electrons from an electron acceptor compound in a chemical reaction. The redox potential is determined by using a standard hydrogen electrode or other standard electrode. The redox potential of the sulfinic acid derivative used as reducing agent in the composition according to the invention is at least 800mV, or at least 825mV, or at least 850mV. The redox potential should be at most 1000mV, or at most 975mV or at most 950mV. In preferred embodiments, the reduction potential of the sulfinic acid derivative reducing agent is 800mV to 1000mV, or 825mV to 975mV, or 800mV to 950mV.

At least one sulfinic acid derivative reducing agent is present in the composition according to the invention in an amount of at least 3 wt.%, or at least 6 wt.%, or at least 7 wt.%, or at least 8 wt.%, or at least 9 wt.%. The amount is at most 30 wt%, or at most 25 wt%, or at most 20 wt%, or at most 15 wt%, or at most 13 wt%. Preferably, the amount of at least one reducing agent in the composition according to the invention is in the range of 3 to 30 wt%, or 6 to 25 wt%, or 7 to 20 wt%, or 8 to 15 wt%, or 5 to 15 wt%, or 9 to 13 wt%. The amounts in% by weight are in each case based on the total weight of the composition according to the invention.

The term "fabric" as used in the context of the present application refers to the generic terms "fiber", "fiber mixture", "yarn", "knitted fabric", "nonwoven" and "woven" fabric. Preferably, the fabric used according to the application comprises or consists of cellulose fibres. The term "fiber mixture" as used in the context of the present application means that at least two fibers are combined into one fiber mixture by known spinning methods, wherein the at least two fibers are made of different materials: at least one of the fibers is made of cellulose or consists of cellulose, wherein the second fiber is made of polyamide, silk or wool fibers or consists of polyamide, silk or wool fibers. Thus, the term fiber mixture as used in the context of the present application refers to a combination of at least two fibers, one of which is made of cellulose and the second of which is made of polyamide, silk or wool fibers.

The term "woven" as used in the context of the present application refers to a two-dimensional or three-dimensional fabric made from yarns by a weaving process. The yarns used to make the braid may consist of fibers or a mixture of fibers as defined above. The term "yarn" as used in the context of the present application refers to the agglomeration of fibers, according to the present application, of a mixture of fibers as defined above, wherein the agglomeration is achieved by a spinning process. This means that the yarn may contain a mixture of two or more fibres as defined above, depending on the desired yarn properties, such as strength or thickness.

The term "nonwoven" as used in the context of the present application refers to a two-or three-dimensional fabric made from yarns that have been chemically, mechanically, thermally, or solvent treated, i.e., bonded together by a process other than the weaving process. The yarns used to make the nonwoven consist of fibers or a mixture of fibers as defined above.

The term "knitted fabric" as used in the context of the present application refers to a two-or three-dimensional fabric made from yarns as defined above by a knitting process.

The textile material used for discharge printing preferably comprises or consists of cellulose and is preferably cotton and/or viscose.

Fabrics for discharge printing according to the present application are usually pre-dyed with a ground dye. The term "ground dye" as used in the context of the present application refers to a fabric that is fully or partially dyed with one or more dyes that are sensitive to reduction imparted by at least one reducing agent. Suitable dyes for use as a dischargeable base dye generally contain azo groups which are decomposed when treated with a sulfinic acid derivative reducing agent, so that a discharge effect can be observed. Such dyes are commonly referred to as reactive dyes.

The term "reactive dye" as used in the context of the present application refers to a "fiber-reactive azo dye" or a "vinyl sulfone dye". Reactive dyes are well known in the art. Reactive dyes are characterized in that the chromophore of the dye contains one or more substituents capable of reacting with the textile substrate (e.g. fiber mixtures consisting of or comprising cellulose, polyamide, silk, wool fibers, yarns, woven, non-woven and knitted fabrics). Reactive dyes are a class of organic dye materials that contain at least one substituent that reacts with the substrate to form a covalent bond between the dye molecule and the substrate to be colored. For example, WO 2007/039573 A2 relates to mixtures of azo-reactive dyes and fibre-reactive azo dyes, to a process for their preparation and to their use for colouring and printing hydroxyl-and carboxamido-containing materials. Furthermore, WO 2004/088031 discloses mixtures of azo reactive dyes and fibre reactive dyes, their preparation and their use. WO 2015/149940 relates to compounds obtained by coupling two diazotized forms of an aminoaryl compound onto a 3-aminophenylurea. These compounds are used as azo reactive dyes in colouring and printing processes. Examples of reactive dyes for dyeing textiles (to be treated with the composition according to the application) are reactive red 35, reactive red 106, reactive orange 13, reactive blue 250, reactive blue 28, reactive yellow 15, reactive yellow 43 or reactive black 5.

The term "discharge printing" as used in the context of the present application refers to a process of discharging (i.e. removing) color from dyed (i.e. colored) fabrics by applying a composition (e.g. a composition according to the present application) to the fabrics under printing conditions. According to the application, the composition for discharge printing can be used in the form of a paste. According to the application, at least one composition according to the application is used for discharge of colour from a fabric. Optionally, additional pigments resistant to sulfinic acid derivative reducing agents may also be included in the composition according to the application, to achieve coloration of the discharge printed areas on the fabric. During the printing process, the discharge printing composition is applied to the colored fabric, thereby producing a discharge of color. The term "discharge" in the context of the present application means that the ground dye of the fabric is bleached. "bleaching" herein refers to bleaching of the base dye by treatment with a sulfinic acid derivative reducing agent. In case the base dye has completely faded, a preferred bleaching effect is obtained.

Various printing processes for printing textiles are known in the art: for example, lithographic printing, perrotine printing, roller printing, cylinder printing or machine printing, stencil printing, screen printing or flat printing, digital textile printing, flexographic textile printing. The composition according to the application is suitable for use in printed textiles, in particular in each of the known processes for printing woven, non-woven and knitted textiles. In particular, the printing process or printed fabric is characterized by the application of a defined pattern or design to the fabric. Thus, the term "printed" as used in the context of the present application refers to a fabric that has been subjected to a printing process as defined above by discharge of a base dye from the fabric. The term "printed" also refers to fabrics in which the discharged base dye is replaced by a pigment having resistance to at least one reducing agent of the composition according to the application, so as to recolour the fabric. The discharge printing process without pigment is also called "white discharge printing". The discharge printing process with pigments is also known as "color discharge printing".

Furthermore, the composition according to the invention comprises at least one synthetic thickener. The thickener serves to increase the desired final viscosity level of the composition that is capable of printing and to maintain the form of the printed pattern with good definition, avoiding water flushing away the colour.

The desired viscosity of the composition according to the invention is at least 3000 mPa-s, or at least 3500 mPa-s or at least 3800 mPa-s. The viscosity of the composition should be at most 5000 mPas, or at most 4500 mPas, or at most 4200 mPas. The preferred viscosity of the composition according to the invention is in the range of 3000 mPas to 5000 mPas, or 3500 mPas to 4500 mPas, or 3800 mPas to 4200 mPas. Typical thickeners used in the printing process are characterized by their viscosity increasing behaviour. Basically, natural thickeners and synthetic thickeners are used in printing processes for printed fabrics. However, with the composition according to the invention, natural thickeners suffer from their poor delayed viscosity increasing behaviour. Thus, insufficient time may be required for the viscosity of the natural thickener in the printing composition to develop to the desired final level. Thus, in the case of the composition according to the invention, the processability of the discharge printing process using natural thickeners is severely impaired. In contrast, the synthetic thickeners used in the compositions according to the invention are based on polymers obtained from acrylic acid and its derivatives, and are preferably used in the claimed discharge printing process. The desired viscosity level of the composition according to the invention increases within 1 hour, preferably within 40 minutes, more preferably within 30 minutes. Thus, the process performance of the discharge process is significantly improved compared to processes using natural thickener products. The development of viscosity characteristics of liquids or amorphous solids is primarily dependent on interparticle forces in solution, including intermolecular friction and attractive forces in the macrostructure. These van der waals forces are key factors in the resistance of the sample to deformation or flow, which determine the viscosity of the material. Dynamic viscosity represents a measure of the shear stress per unit area required before the sample begins to deform. The viscosity is generally expressed in millipascal seconds (mpa·s). Standard test methods for determining dynamic viscosity and density of liquids were performed by a stabinger viscometer according to ASTM D7042.

At least one synthetic thickener is present in the composition according to the present application in an amount of at least 0.05 wt.%, or at least 0.5 wt.%, or at least 1 wt.%, or at least 1.5 wt.%, or at least 1.8 wt.%. The amount of at least one synthetic thickener in the composition according to the application is at most 6 wt.%, or at most 5 wt.%, or at most 4 wt.%, or at most 3 wt.%, or at most 2.3 wt.%. Preferably, the amount of at least one synthetic thickener in the composition according to the present application is in the range of 0.05 to 6 wt%, or 0.5 to 5 wt%, or 0.5 to 4 wt%, or 1 to 4 wt%, or 1.5 to 3 wt%, or 1.8 to 2.3 wt%. The amounts in% by weight are in each case based on the total weight of the composition according to the application.

The synthetic thickeners used in the compositions according to the application are further characterized in that they do not react adversely with at least one reducing agent. The discharge printed fabric exhibits high color yield, brightness and levelness and is free from a spot problem, i.e., printing can be performed with a very fine screen, thereby realizing a printed image with a clear outline. In general, the viscosity increasing effect of the above-described synthetic thickeners in the discharge composition according to the application is superior to that of natural thickeners. Thus, a lesser amount of thickener than natural thickeners can be used while achieving the same viscosity of the discharge printing composition. The term "synthetic thickener" as used in the context of the present application refers to a thickener, i.e. a compound capable of increasing the desired viscosity level of a liquid composition, which is not of natural origin, i.e. not derived from a plant, algae or animal product. In one embodiment, the at least one thickener is a polyacrylic acid compound, i.e. a polymer or copolymer composed of one or more derivatives of acrylic acid and acrylic esters, wherein the at least one synthetic thickener is a copolymer based on acrylic acid monomers or derivatives thereof. The synthetic thickener is preferably used as an inverse emulsion of a copolymer in oil based on acrylic monomers or derivatives thereof, which swells and increases viscosity when combined with water. Preferably, the synthetic thickener comprises a high density oil and/or an auxiliary agent, such as a nonionic surfactant. Suitable synthetic thickeners are known under the trade name Lutexal, lyoprint, tubivis, printex, uniprint.

In a preferred embodiment of the first aspect of the application, the composition is free of any natural thickeners. Natural thickeners, such as those based on sodium alginate or guar gum, often require long times to increase the final viscosity level, which is required for uniform application of the composition for discharge printing to fabrics. Thus, in the case of using natural thickeners in the compositions according to the application, the processing time of the discharge printing process is significantly longer. The term "natural thickener" as used in the context of the present application refers to thickeners of natural origin, e.g. derived from plants, such as guar, algae or animal products.

The composition according to the application further optionally comprises at least one binder. The at least one adhesive has the advantage of forming a film on the fabric to which the adhesive is applied. At least one pigment optionally present in the composition according to the application is immobilized on the fabric by film formation. Thus, under the term "binder" as used in the context of the present application, a component is understood to be capable of forming a film on the fabric to which it is applied (woven) to thereby fix the pigment on the substrate. The binder optionally present in the composition according to the application is designed to comprise a liquid medium and an aqueous dispersion of polymer particles dispersed therein. The liquid medium comprises or consists of water, one or more surfactants or mixtures thereof. Preferably, the liquid medium does not contain any organic solvent. This has the advantage that the adhesive has low flammability. The polymer particles dispersed in the liquid medium have an average particle diameter of 120 to 300nm. The polymer particles are responsible for forming the film. The liquid medium is the reaction medium in which the polymer particles are formed and acts as a stabilizer for the polymer particles dispersed therein during transportation and storage. The polymer particles dispersed in the liquid medium are produced by emulsion polymerization. The monomers that should constitute the polymer particles are dispersed in a liquid medium and the polymerization is initiated by free radical polymerization. Suitable monomers are unsaturated monomers selected from the group comprising: vinyl chloride, ethylene dichloride, acrylic acid, methacrylic acid, acrylamide, acrylonitrile, acrylic esters, vinyl esters, styrene, dienes (e.g., butadiene), or mixtures thereof. The binder comprises a high content of polymer particles, in particular at least 35 wt%, or at least 40 wt%, or at least 45 wt% or at most 50 wt%, based on the total weight of the binder, wherein the balance up to 100 wt% consists of a liquid medium being water, a surfactant or a mixture thereof. As mentioned above, the binder used in the composition according to the application is designed as a dispersion as defined above and is therefore present in the composition according to the application as a dispersion comprising or consisting of polymer particles dispersed in a liquid medium. Once the substrate (in this case the fabric) has undergone a heating step, in particular a drying step, a film is formed on the substrate to which the adhesive (or in this case the composition according to the application) has been applied. The liquid medium is then removed, for example by evaporation, and the previously dispersed polymer particles coalesce and flow together, thereby forming a three-dimensional network, i.e. a film, in which the pigment is entrapped. Since the film is a three-dimensional network, the fixation of the film on a substrate, in particular on a fabric, is achieved. Thus, another advantage of the adhesive is to ensure that the entrapped pigment is resistant to abrasion and cleaning. Suitable polymers are, for example, poly (butyl acrylate), copolymers of butyl (acrylate), ethyl (acrylate) and styrene, polyethylene acrylates, acrylonitrile or mixtures thereof. Suitable binders are known under the trade names Helizarin (aqueous acryl vinyl copolymer dispersion), cresacryl, unicryl or Tubifast. In the case where at least one binder is present in the composition according to the application, its amount is at least 2.5 wt.%, or at least 5 wt.%, or at least 10 wt.%, or at least 15 wt.%. Where the binder is present in the composition according to the application, the amount is at most 30 wt%, or at most 25 wt%, or at most 20 wt%, or at most 19 wt%. Preferably, in the case where the binder is present in the composition according to the application, the amount of binder in the composition according to the application is in the range of 2.5 to 30 wt%, or 5 to 25 wt%, or 5 to 19 wt%, or 10 to 20 wt%, or 15 to 20 wt%. The amounts in% by weight are in each case based on the total weight of the composition according to the application.

The composition according to the application comprises at least one wetting agent. In the context of the present application, the term "wetting agent" refers to a hygroscopic compound. The wetting agent used in the composition according to the application avoids that the fabric treated in the discharge printing process dries too fast. Although the composition according to the application achieves a shorter total drying time, since a higher drying temperature can be applied, the discharge of the ground dye of the fabric requires a moist environment. Thus, too fast drying of the discharge printed areas on the fabric can result in incomplete discharge. Preferred humectants are urea and glycerol. Further wetting agents are ethylene glycol, polyethylene glycol and salts. In one embodiment, urea is used as a wetting agent. In another embodiment, it is preferred that a mixture of urea and glycerol be used as the wetting agent.

The wetting agent is present in the composition according to the application in an amount of at least 3 wt.%, or at least 5 wt.%, or at least 10 wt.%, or at least 15 wt.%, or at least 20 wt.%. The amount of wetting agent in the composition according to the application is at most 45 wt.%, or at most 40 wt.%, or at most 35 wt.%, or at most 30 wt.%. Preferably, the amount of wetting agent in the composition according to the application is in the range of 3 to 45 wt%, or 5 to 40 wt%, or 10 to 15 wt%, or 10 to 35 wt%, or 15 to 30 wt%. The amounts in% by weight are in each case based on the total weight of the composition according to the application.

In a preferred embodiment, wherein the composition according to the invention comprises urea and glycerol as wetting agents, the amount of urea present in the composition according to the invention is at least 0.5 wt.%, or at least 2 wt.%, or at least 5 wt.%, or at least 10 wt.%. In this case, the amount of urea is at most 30 wt.%, or at most 25 wt.%, or at most 20 wt.%. Preferably in this case the amount of urea is from 0.5 to 30 wt%, or from 2 to 25 wt%, or from 10 to 20 wt%. The amounts in% by weight are in each case based on the total weight of the composition according to the invention. The amount of glycerol present in the composition according to the invention is at least 0.1 wt%, or at least 1 wt%, or at least 3 wt%. In this case, the amount of glycerol is at most 15 wt%, or at most 10 wt%, or at most 5 wt%. Preferably in this case the amount of glycerol is from 0.1 to 15 wt%, or from 2 to 10 wt%, or from 3 to 5 wt%, or from 1 to 5 wt%. The amounts in% by weight are in each case based on the total weight of the composition according to the invention. In any case, however, the total amount of glycerol and urea is not less than 3% by weight and at most 45% by weight.

The composition according to the invention comprises at least one pH regulator. The pH adjustor helps maintain the pH of the composition within a specified range. The thickener is stable over a defined pH range and the homogeneous character of the composition is maintained. The preferred pH value of the composition according to the invention is in the range of pH 8 to pH 9. Preferred pH adjusting agents are selected from tertiary amines, ammonia or ammonium salts and derivatives thereof, which preferably volatilize when the fabric is dried. The preferred pH adjuster is triethanolamine. At least one pH adjuster is present in the composition according to the invention in an amount of at least 0.05 wt%, or at least 0.1 wt%, or at least 0.5 wt%, or at least 0.75 wt%. The pH adjusting agent is present in the composition according to the invention in an amount of up to 4 wt%, or up to 2 wt%, or up to 1 wt%, or up to 1.25 wt%. Preferably, the amount of pH adjuster in the composition according to the invention is in the range of 0.05 to 4 wt%, or 0.1 to 2 wt%, or 0.5 to 1 wt%, or 0.75 to 1.25 wt%, or 0.1 to 0.4 wt%. The amounts in% by weight are in each case based on the total weight of the composition according to the invention.

Since the composition according to the application is an aqueous composition, the balance up to 100% by weight is water. The composition according to the application is preferably applied to the fabric as a printing paste. Thus, a certain amount of fluid carrier is necessary to be able to provide a uniform printing paste, wherein all the desired compounds are uniformly distributed. The term "fluid carrier" as used in the context of the present application refers to a liquid capable of imparting fluid properties to the composition according to the present application such that the components of the printing paste can be uniformly printed onto the fabric. According to the application, water is used as a fluid carrier.

The composition according to the application optionally comprises at least one pigment. The at least one pigment may be added to the composition according to the application in the form of a pigment dispersion. Thus, the composition according to the application may comprise at least one dispersion comprising at least one pigment. In the case of the use of at least one pigment in the composition, the color discharge areas on the fabric are immediately colored by the pigment during the printing process. In the case where pigments are present in the composition according to the application, there is also at least one binder as defined herein, since the pigments are fixed to the fabric by the binder, and the fabric is (re) coloured. The pigments used in the color discharge process according to the application need to be resistant to at least one reducing agent. Typical pigments useful within the scope of the present application are anthraquinone, phthalocyanine, triphenylmethane, carbon black, inorganic pigments, quinacridone, monoazo and diazo pigments. In the composition according to the application, which is required for color discharge printing, at least one pigment dispersion is present in the composition in an amount of at least 0.01% by weight, or at least 0.02% by weight, or at least 0.5% by weight, or at least 1% by weight. In one embodiment, the amount of at least one pigment dispersion in the composition according to the application is at most 6 wt.%, or at most 5 wt.%, or at most 4 wt.%, or at most 3 wt.%. Preferably, the amount of at least one pigment dispersion in the composition according to the application is in the range of 0.01 to 6 wt%, or 0.02 to 5 wt%, or 0.5 to 4 wt%, or 1 to 3 wt%. The amounts in% by weight are in each case based on the total weight of the composition according to the application.

According to a first aspect of the invention, the composition may further comprise one or more additives selected from the group comprising: a cross-linking agent, a softening agent, an emulsifying agent, a defoamer, a rheology modifier and an oxidation protectant or a mixture thereof.

The cross-linking agent is capable of fixing the pigment to the fabric in a color discharge printing process. The fastness of the dyed fabric is thus improved. The crosslinking agent may be present in the composition according to the invention in an amount of at least 0.1 wt.%, or at least 0.2 wt.%, or at least 0.5 wt.%, or at least 0.75 wt.%. The crosslinking agent may be present in the composition according to the invention in an amount of up to 3 wt.%, or up to 2.5 wt.%, or up to 2 wt.%, or up to 1.5 wt.%. Preferably, the amount of cross-linking agent in the composition according to the invention is in the range of 0 to 3 wt%, or 0.1 to 3 wt%, or 0.2 to 2.5 wt%, or 0.5 to 2 wt%, or 0.75 to 1.5 wt%. The amounts in% by weight are in each case based on the total weight of the composition according to the invention. A suitable is knownIs available under the trade name ofFixing Agent SE.01liq。

The softener imparts a smooth hand to the treated fabric during the discharge printing process. The softening agent used in the composition according to the invention is silicon-based. The softening agent may be present in the composition according to the invention in an amount of at least 0.1 wt%, or at least 0.2 wt%, or at least 0.5 wt%, or at least 0.75 wt%. The softening agent may be present in the composition according to the invention in an amount of up to 3 wt.%, or up to 2.5 wt.%, or up to 2 wt.%, or up to 1.5 wt.%. Preferably, the amount of softening agent in the composition according to the invention is in the range of 0 to 3 wt%, or 0.1 to 3 wt%, or 0.2 to 2.5 wt%, or 0.2 to 2 wt%, or 0.5 to 2 wt%, or 0.75 to 1.5 wt%. The amounts in% by weight are in each case based on the total weight of the composition according to the invention. A suitable softener is known under the trade name Soft VSN liq。

The emulsifier enables the composition according to the invention to be provided as an emulsion, in particular a stable emulsion. The various components of the composition according to the invention are themselves provided by the manufacturer in emulsified form. The emulsifier combines with the components provided in emulsified form to form a combined primary emulsion. Thus, each component can be uniformly dispersed into the main emulsion, which enables the manufacture of a uniform and accurate printed pattern. At least one emulsifier is present in the composition according to the invention in an amount of at least 0.05 wt%, or at least 0.1 wt%, or at least 0.3 wt%, or at least 0.5 wt%. The emulsifier may be present in the composition according to the invention in an amount of up to 2 wt.%, or up to 1.5 wt.%, or up to 1 wt.%, or up to 0.8 wt.%. Preferably, the amount of at least one emulsifier in the composition according to the invention is between 0 and 2% by weight, or 0.05% by weightTo 2 wt%, or 0.1 wt% to 1.5 wt%, or 0.3 wt% to 1 wt%, or 0.5 wt% to 0.8 wt%. The amounts in% by weight are in each case based on the total weight of the composition according to the invention. A suitable emulsifier is known under the trade name Emulsifier PE New liq c。

The defoamer prevents the adverse effects of foam formation during the manufacture of the composition according to the invention and/or during discharge printing using said composition. Foaming tends to render the composition for discharge printing non-uniform, thereby creating a non-uniform printed pattern on the fabric. The defoamer may be present in the composition according to the present invention in an amount of at least 0.05 wt%, or at least 0.1 wt%, or at least 0.15 wt%. The defoamer may be present in the composition according to the invention in an amount of up to 1 wt.%, or up to 0.8 wt.%, or up to 0.4 wt.%, or up to 0.3 wt.%. Preferably, the amount of defoamer in the composition according to the present invention is in the range of 0 to 1 wt%, or 0.05 to 1 wt%, or 0.1 to 0.8 wt%, or 0.1 to 0.4 wt%, or 0.15 to 0.3 wt%. The amounts in% by weight are in each case based on the total weight of the composition according to the invention. A suitable defoamer is known under the trade nameUDF(1:10)。

The rheology modifier improves the surface tension of the composition according to the invention. In addition, the rheology modifier improves the stability of the thickener. Thus effectively improving the stability of the printed surface on the fabric. Preferred rheology modifiers for use in the compositions of the present invention are polyacrylate copolymer emulsions or polyurethane dispersions, or mixtures thereof. The at least one rheology modifier may be present in the composition according to the invention in an amount of at least 0.05 wt%, or at least 0.1 wt%, or at least 0.15 wt%, or at least 3 wt%. The at least one rheology modifier may be present in the composition according to the invention in an amount of up to 2 wt%, or up to 1.5 wt%, or up to 1 wt%, or up to 0.8 wt%. Preferably, the amount of rheology modifier in the composition according to the invention is in the range of 0 to 2 wt%, or 0.05 to 2 wt%, or 0.1 to 1.5 wt%, or 0.15 to 1 wt%, or 0.2 to 1 wt%, or 0.3 to 0.8 wt%. The amounts in% by weight are in each case based on the total weight of the composition according to the invention. One suitable rheology modifier is known under the trade name Luprintol Additive RM 01liq.

The oxidation protectant protects the pigment used in the compositions of the present invention from oxidation during printing and drying. Effectively, when an oxidation protectant is used in the composition, less yellowing is achieved during discharge printing and the quality of the printed picture is improved. The preferred oxidation protectant used in the composition according to the invention is m-nitrobenzenesulfonate or a derivative thereof. At least one oxidation protecting agent is present in the composition according to the invention in an amount of at least 0.05 wt%, or at least 0.1 wt%, or at least 0.2 wt%, or at least 0.3 wt%, or at least 0.5 wt%. The at least one oxidation protecting agent may be present in the composition according to the invention in an amount of up to 2 wt.%, or up to 1.5 wt.%, or up to 1%, or up to 0.8 wt.%. Preferably, the amount of at least one oxidation protecting agent in the composition according to the invention is in the range of 0 to 2 wt%, or 0.05 to 2 wt%, or 0.1 to 1.5 wt%, or 0.2 to 1.5 wt%, or 0.3 to 1 wt%, or 0.3 to 0.8 wt%, or 0.5 to 1.5 wt%. The amounts in% by weight are in each case based on the total weight of the composition according to the invention. One suitable oxidizing agent is known under the trade name revtol NS liq.

According to a first aspect of the invention, the composition comprises or consists of:

3 to 30 wt% of at least one reducing agent,

0.05 to 6% by weight of at least one synthetic thickener,

3 to 45% by weight of at least one wetting agent,

0.05 to 4% by weight of at least one pH regulator,

0 to 30% by weight of at least one binder,

0 to 2% by weight of at least one emulsifier,

0 to 1% by weight of at least one defoamer,

0 to 3% by weight of at least one crosslinking agent,

0 to 3% by weight of at least one softener,

0 to 2% by weight of at least one rheology modifier,

0 to 2% by weight of at least one oxidation protecting agent,

0 to 6% by weight of at least one pigment dispersion,

the balance to 100 wt% being water,

wherein weight% is based on the total weight of the composition according to the invention.

Furthermore, the composition according to the invention may comprise or consist of:

3 to 30 wt% of at least one reducing agent,

0.05 to 6% by weight of at least one synthetic thickener,

3 to 45% by weight of at least one wetting agent,

0.05 to 4% by weight of at least one pH regulator,

0.05 to 2% by weight of at least one emulsifier,

0.05 to 1% by weight of at least one defoamer,

0.1 to 3% by weight of at least one crosslinking agent,

0.1 to 3% by weight of at least one softener,

0.05 to 2% by weight of at least one rheology modifier,

0.05 to 2 wt% of at least one oxidation protecting agent, and optionally

0.01 to 6% by weight of at least one pigment dispersion,

2.5 to 30% by weight of at least one binder,

the balance to 100 wt% is water, wherein wt% is based on the total weight of the composition.

5 to 15 wt% of at least one reducing agent,

1 to 4% by weight of at least one synthetic thickener,

10 to 30 wt% of at least one wetting agent,

0.2 to 2% by weight of at least one pH regulator,

0.05 to 2% by weight of at least one emulsifier,

0.1 to 0.4% by weight of at least one defoamer,

0.5 to 2% by weight of at least one crosslinking agent,

0.2 to 2% by weight of at least one softener,

0.2 to 1% by weight of at least one rheology modifier,

0.2 to 1.5% by weight of at least one oxidation protecting agent, and optionally

0.5 to 4% by weight of at least one pigment dispersion,

From 5 to 19% by weight of at least one binder,

the balance to 100 wt.% is water, wherein wt.% is based on the total weight of the composition according to the invention.

In a second aspect, the present invention relates to a method of manufacturing a discharge printing composition according to the first aspect of the invention. Accordingly, the details, definitions and limitations described above in relation to the composition according to the first aspect of the invention also apply to the method according to the second aspect of the invention. The method according to the invention comprises or consists of the following step a and optionally steps B and C:

step A: in the presence of at least one pigment in the composition according to the invention, all components of the composition according to at least one embodiment of the first aspect of the invention, except for the at least one pigment,

and (B) step (B): adding at least one dispersion comprising at least one pigment to the mixture obtained in step a,

step C: the mixture obtained in step B is mixed and homogenized.

In step a, all components of the composition according to the invention are mixed and homogenized, except for optionally at least one pigment. The composition obtained in step a yields a composition according to the invention suitable for white discharge printing. The composition may be in the form of a paste. The mixing and homogenizing can be carried out in customary equipment for mixing and homogenizing components, in particular for mixing and homogenizing components of pastes, in particular pastes for discharge printing. The preferred apparatus for step a is a super shear mixing blade. The mixing and homogenization of the components may be carried out at any suitable stirring speed for any suitable time, for example at a stirring speed of 200rpm to 4000rpm for 5 to 15 minutes.

Optional step B comprises: at least one pigment is added, which may be added as a dispersion comprising the pigment to the mixture obtained in step a. Step B may be performed immediately after step a. It is also possible to store the mixture obtained in step a for a period of time before step B is carried out. In addition, other components may be added to the composition obtained in step a. It is also possible to premix the other components with at least one pigment added to the mixture obtained in step a.

Optional step C comprises: the mixture obtained in step B is mixed and homogenized. The composition obtained in step C yields a composition according to the invention suitable for color discharge printing. The mixing and homogenizing can be carried out in customary equipment for mixing and homogenizing components, in particular for mixing and homogenizing components of pastes, in particular pastes for discharge printing. The preferred apparatus for step C is a high speed mixer. Step C may be performed immediately after step B. The mixture obtained in step B may also be stored for a period of time before step C is performed. Once step C is complete, the composition according to the invention can be ready for use, i.e. ready for application to fabrics. Preferably, after step C is completed, the composition according to the invention is designed as a discharge printing paste.

In the case of the color discharge printing process, optional steps B and C are carried out. Optional step B may be performed before or simultaneously with step a.

Furthermore, additional steps may be performed before step a, after step C, or between steps A, B and/or C. Possible steps are for example a heating step, a cooling step, a sieving step.

In a third aspect, the present application relates to the use of a composition according to the first aspect of the present application, or of a formaldehyde-free aqueous composition manufactured according to the process of the second aspect of the present application, for a discharge printing process, in particular for a white discharge or color discharge printing process of a fabric. The above details, definitions and limitations regarding the first aspect of the application and the second aspect of the application thus also apply to the use according to the third aspect of the application. Preferably, the fabric used comprises or consists of cellulosic fibres (e.g. cotton).

In the context of the present application, the term "white discharge printing process" refers to a printing process in which the printing composition without any pigment is used for discharge printing. Thus, the printed fabric is characterized by a color discharge in the printed area, wherein the natural color of the fabric fibers becomes visible.

In the context of the present application, the term "colour discharge printing process" refers to a printing process in which a printing composition comprising at least one pigment is used for discharge printing. The printed fabric is characterized in that the colored discharge areas are covered, i.e. colored or dyed by pigment colors.

In a fourth aspect, the present application relates to a discharge printing process for printing textiles. The details, definitions and limitations described above in relation to the first aspect of the application, the second aspect of the application and the third aspect of the application also apply to the discharge printing method according to the fourth aspect of the application. The discharge printing method according to the application comprises or consists of the following steps:

step 1: a colored fabric is provided which is a solid,

step 2: and (3) printing: printing a fabric with the formaldehyde-free aqueous composition according to the first aspect of the application, or printing a fabric with the formaldehyde-free aqueous composition manufactured by the method according to the second aspect of the application,

step 3: a first drying step: the fabric obtained in step 2 is dried,

step 4: washing: washing the fabric obtained in step 3, wherein the fabric is rinsed with a rinsing liquid and/or soaped with a soaping liquid,

step 5: and a second drying step: drying the fabric obtained in step 4.

The discharge printing process according to the present application does not require an additional steaming process step as in the discharge printing processes known in the prior art. Thus, the processing time and energy consumption are significantly reduced compared to known discharge printing methods. The discharge printing method according to the present application does not use any formaldehyde releasing agent. In particular, the composition, rinse solution, wash solution and optional finish according to the first aspect of the application is free of formaldehyde releasing agents. Thus, in the discharge printing method according to the present application, no unpleasant smell or burden harmful to the environment is generated. It has also been observed that the long and intense washing steps employed in the art-known discharge printing methods for eliminating formaldehyde residues can be reduced.

The composition according to the first aspect of the application or the composition manufactured according to the method of the second aspect of the application for use in the discharge printing method according to the fourth aspect of the application is preferably designed as a paste. Printing may be carried out by conventional printing methods for printing textiles known in the art, for example by rotary or flat printing machines.

After drying, the printed fabric is subjected to a washing step for washing the fabric in step 4. The fabric is rinsed with a rinse solution and/or soaped with a soaping solution to remove components of the printing paste. In the context of the present application, the term "rinse liquid" refers to a fluid capable of rinsing solids and/or soluble residues remaining on the fabric after the first drying according to step 3 from the fabric. Preferably, the rinse solution is water or H-based ₂ O ₂ Is a solution of (a) and (b). In one embodiment, the fabric is rinsed with water and/or soaped with a soaping liquid to removeThe components of the printing paste. The term "soaping liquid" refers to an aqueous fluid used to remove from a fabric lipophilic residues remaining on the fabric after the first drying step according to step 3. Typically, soap washes are based on aqueous fluids comprising detergents. The washing step may include one or more of the following procedures: cold rinsing, warm rinsing and/or hot soaping. The washing step may be performed immediately after the first drying step. The printed fabric may also be stored for a period of time after the first drying step, before the washing step is performed.

After washing, the printed fabric is subjected to a second drying step. Thus, the cleaned fabric is provided in dry form and may be subjected to possible further processing steps, such as finishing steps. Other possible steps may be performed such as heating, cooling, pressing to shape the printed fabric for use.

The discharge printing method according to the present invention comprises as step 4 a washing method comprising or consisting of:

a first cold rinsing and/or hot rinsing step, wherein a cold water or H is used ₂ O ₂ The aqueous rinse solution rinses the printed fabric, and/or,

a hot soaping step in which the printed fabric is washed with a soaping liquid selected from soapy water at a temperature of 40-80 ℃,

and/or the number of the groups of groups,

a second cold rinse step in which the printed fabric is rinsed with a second rinse selected from cold water.

Can be prepared by using water or H ₂ O ₂ The aqueous rinse solution rinses the printed fabric. Thus, the printed fabric releases the water-soluble components remaining on the printed fabric after the first drying step. In a preferred embodiment, the fluid in the first rinsing step comprises H ₂ O ₂ 。H ₂ O ₂ Destroying the residues of at least one reducing agent remaining on the printed fabric after the first drying step.

In the soaping step, the printed fabric is soaped with a hot soaping liquid. Thus, the printed fabric is free of lipophilic residues remaining on the printed fabric after the first drying step. The hot soaping of the printed fabric is preferably carried out at 40 to 80 ℃. More preferably, the soaping is carried out at 50 to 75 ℃ or 60 to 75 ℃. Preferably, the soaping liquid contains a nonionic soaping agent, such as the commercially known Imertol Jet-B liq c.

The hot soaping step is followed by a second rinsing step. The second rinsing step is performed with cold water to remove any residue from the soaping step. After the second rinsing step, the printed fabric is washed and further subjected to the aforementioned second drying step.

Furthermore, the discharge printing process according to the present invention comprises a step 3, i.e. a first drying step, which is carried out at a temperature of at least 140 ℃, or at least 145 ℃, or at least 150 ℃, or at least 155 ℃. The temperature should be at most 180 ℃, or at most 175 ℃, or at most 165 ℃. In preferred embodiments, the temperature is 140 ℃ to 180 ℃, or 145 ℃ to 175 ℃, or 150 ℃ to 170 ℃, or 155 ℃ to 165 ℃. The drying condition can rapidly realize the white discharge effect of the fabric. In the case of using a composition containing a pigment, high fastness of the pigment is achieved. The drying time of the first drying step is set to at least 1min, or at least 2min and at most 5min or at most 4min. Preferably, the drying time is 1 to 5 minutes, or 2 to 4 minutes.

The discharge printing process according to the invention comprises a step 5, a second drying step, which is carried out at a temperature of at least 120 ℃, or at least 125 ℃, or at least 130 ℃, or at least 135 ℃. The temperature of the second drying step should be at most 160 ℃, or at most 155 ℃ or at most 150 ℃. In preferred embodiments, the temperature in the second drying step is selected from 120 ℃ to 160 ℃, or 125 ℃ to 155 ℃, or 130 ℃ to 150 ℃, or 135 ℃ to 145 ℃. The drying time in the second drying step is set to at least 8min or at least 10min or at least 12min and at most 20min or at most 18min. Preferably the drying time is 8 to 20 minutes or 10 to 20 minutes or 12 to 18 minutes.

For industrial implementation of the method, the fabric may be provided as a fabric web. The web may be stored on a fabric roll. According to a fourth aspect of the application, the fabric is unwound from a fabric roll, fed to one or more steps of a discharge printing process, and then rewound onto the fabric roll.

According to a fourth aspect of the application, a discharge printing process may be performed wherein the printing of the fabric mesh (step 2) and the first drying (step 3) are performed as an in-line process, wherein the fabric mesh is passed through a printing unit, wherein the printing step of the fabric mesh is performed (step 2), and through a first drying unit, wherein the first drying of the fabric mesh is performed (step 3), preferably with a transport speed of 10-30m/min through the printing unit and the first drying unit.

In the context of the present application, the term "printing unit" refers to a printing machine which is configured to transport a fabric through the printing unit and which is further configured to apply the printing composition according to the present application to the fabric for the printing step (step 2) in a discharge printing process. In the context of the present application, the term "drying unit" refers to a drying oven capable of applying drying and heating conditions to a web of fabric, which is further configured such that the web of fabric can be conveyed through the drying unit.

According to the fourth aspect of the present invention, the discharge printing method is performed because it does not include the curing method. The results show that such a curing process is not necessary to produce excellent printed fabrics according to the present invention. As a result, the processing time and energy consumption of the discharge printing method according to the present invention are significantly reduced. Compared with the discharge printing method which is generally known and carried out by using the generally known discharge printing composition, CO ₂ Emissions, energy consumption, and processing time may be reduced by 10%, or 20%, or 25%, or 30%, or 35%, or 40%, or even 45%. The curing process steps employed in the prior art include treating the fabric with hot air. Furthermore, the process according to the invention does not use any steaming process, which is usually carried out with saturated water vapor at high temperature.

In a fifth aspect, the present invention relates to a fabric treated with a composition according to at least one embodiment of the first aspect of the present invention or with a composition obtained according to the second aspect of the present invention in a discharge printing process according to at least one embodiment of the fourth aspect of the present invention. The effect observed with the fabrics processed according to the invention is an improvement in the vividness of white discharge printed and color discharge printed fabrics. The vividness of the fabrics processed according to the present invention is improved over the comparative fabrics processed according to the discharge methods used in the prior art.

Furthermore, the fabrics processed according to the color discharge printing method of the present invention exhibit higher color fastness than the comparative examples processed according to the known discharge printing methods.

Reference is made in this respect to figures 1 and 2.

Fig. 1 shows a fabric sample treated in a color discharge method according to the present invention using a composition according to the present invention, and a comparative fabric sample treated in a baseline method using a baseline composition. Figure 1 shows the higher color fastness of fabric samples processed according to the present invention.

Fig. 2a shows a white discharge fabric sample and a color discharge fabric sample, respectively, processed in a discharge method according to the present invention, using the compositions for white discharge printing and color discharge printing, respectively, according to the present invention.

Fig. 2b shows a white discharge fabric sample and a color discharge fabric sample, respectively, processed according to the reference discharge method known in the art, using reference compositions for white discharge printing and color discharge printing, respectively, also known in the art.

Examples

Example 1: preparation of the composition for discharge printing according to the present invention

In a first step a, according to the specifications shown in table 1, a mixing vessel equipped with a blade stirrer was charged with stirring:

TABLE 1

1.1 composition for white discharge printing

After mixing components 1 to 12 and 14, stirring was then continued for a further 20 minutes at 2000r/min until a final viscosity of 3500 mPas was reached. The pH of the composition was ph=8.5.

1.2 composition for color discharge printing

After mixing components 1 to 12 and 14, stirring was then continued for a further 20 minutes until a final viscosity of 3500 mPas was reached. The pH of the composition was ph=8.6.

In a second step B, a dispersion comprising the pigment Printofix T-B is added to the composition obtained in the first step a with stirring.

In a third step C, the mixture of step B is mixed with stirring and homogenized.

Comparative example 1: reference composition

A base composition was prepared comprising zinc formaldehyde sulfoxylate and a natural thickener in place of the reducing agent and thickener of example 1 commonly used in the art of discharge printing processes.

In a first step a, add to the mixing vessel under agitation according to the specifications shown in table 2:

TABLE 2

1.1 composition for white discharge printing

After mixing components 1 to 5 and 7, stirring was then continued for a further 10 hours at 2000r/min until a final viscosity of 3500 mPas was reached.

1.2 composition for color discharge printing

After mixing components 1 to 5 and 7, stirring was then continued for a further 10 hours min until a final viscosity of 3500 mPas was reached.

Example 2: discharge printing method according to the invention

Provides a bottom dyed satin cotton fabric of 100gr/m ² Is a fabric of (a) a fabric of (b).

2.1 white discharge fabrics

The fabric is provided in the form of a web of fabric wound on a fabric roll. The fabric was unwound and guided through the embossing unit at a transport speed of 20 m/min. The printing composition obtained in example 1.1 was applied to the fabric in a printing unit by the conventional flat screen printing method (J.Zimmer, gmbH; austra-Mini MDF/796). After passing through the embossing unit, the fabric is transferred to a drying unit. The drying and fixing of the print is carried out by drying at 160℃for 2 min. The web is transported out of the drying unit and rewound onto a fabric roll. Subsequently, the printed fabric is washed. The web roll was unwound and the web was conveyed through the washing unit at a conveying speed of 40 m/min. In the washing unit, the fabric was rinsed with water and subsequently treated with 1g/l H at 40℃and 60℃respectively ₂ O ₂ The aqueous solution (w: v) was rinsed for 10 minutes. Thereafter, the web was washed in soapy water containing 1g/l (w: v) of anionic soaping agent (Kiermalon Jet B cont. Liq.) at 70℃for 10 minutes. Subsequently, the web was rinsed with cold water for 10 minutes, air-dried and rewound onto a fabric roll.

2.2 color discharge fabrics

The procedure of example 2.1 was repeated except that the composition obtained according to example 1.2 was used in place of the composition obtained in preparation example 1.1 during discharge printing.

Comparative example 2: reference printing method

The baseline printing process is performed as commonly used in the art.

2.1 white discharge fabrics

The base fabric of example 2 is provided as a web of fabric wound onto a fabric roll. The fabric was unwound and guided through the embossing unit at a transport speed of 20 m/min. In the printing unit, the printing composition obtained according to comparative example 1.1 was applied to the fabric by the conventional flat screen printing method (J.Zimmer, gmbH; austra-Mini MDF/796). After passing through the embossing unit, the fabric is transferred to a drying unit. The drying and fixing of the print is carried out by drying at 135℃for 1min, steaming at 102℃for 10min and curing at 150℃for 5 min. The web is transported out of the drying unit and rewound onto a fabric roll. Subsequently, the printed fabric is washed. The web was unwound and conveyed through the washing unit at a conveying speed of 20 m/min. In the washing unit, the fabric was rinsed with water and subsequently treated with 1g/l H at 40℃and 60℃respectively ₂ O ₂ The aqueous solution (w: v) was rinsed for 10 minutes. Thereafter, the web was washed in soapy water containing 1g/l (w: v) of anionic soaping agent (Kiermalon Jet B cont. Liq.) at 70℃for 20 minutes. Subsequently, the web was rinsed with cold water for 30 minutes, air-dried and rewound onto a fabric roll. The washing time required was at least twice as long as in example 2.1.

2.2 color discharge fabrics

The process of comparative example 2.1 was repeated except that the composition obtained according to comparative example 1.2 was used in place of the composition obtained in comparative example 1.1 during printing.

Examples 2.1 and 2.2 and comparative examples 2.1 and 2.2 were compared in terms of the desired end point of the printing process according to the invention, i.e. contamination of zinc derivatives, formaldehyde release, energy consumption and processing time.

TABLE 3 Table 3

The presence of zinc was determined according to EN 16711-2:2016. The presence of formaldehyde was determined according to AATCC 112. The data in table 3 show that no zinc or formaldehyde contamination was detected for the printing process according to the invention. Furthermore, according to the printing method of the present invention, the energy consumption and the processing time can be reduced by almost half.

Example 3: color fastness and color intensity of fabric samples processed according to the invention

3.1 a sample of the fabric printed according to the colour discharge method of example 2.2 was prepared and its crockfastness studied.

The fabric samples prepared according to example 2.2 were subjected to home washing at 60 ℃. These samples were then subjected to dry rub and wet rub fastness measurements according to ISO 105/X12.

The fabric samples exhibited a dry crock of 4.2 and a wet crock of 2.9.

3.2 the relative color intensity (K/S) of the printed fabric was measured by the Kubelka-Munk equation using light reflectance techniques. The reflectance (R) of the printed fabric was measured on Konica Minolta MF-3700d (Japan). The color intensity of the samples was measured to be increased by at least 27% as compared to comparative example 3 below.

Comparative example 3: color fastness and color intensity of fabric samples processed according to the benchmark method

3.1 a sample of the fabric printed according to the color discharge method of comparative example 2.2 was prepared and its crockfastness was studied.

The fabric samples prepared according to comparative example 2.2 were subjected to home washing at 60 ℃. These samples were then subjected to dry rub and wet rub fastness measurements according to ISO 105/X12.

The fabric samples exhibited a dry crock fastness of 3.2 and a wet crock fastness of 2.4.

3.2 the relative color intensity (K/S) of the printed fabric was measured by the Kubelka-Munk equation using light reflectance techniques. The reflectance (R) of the printed fabric was measured on Konica Minolta MF-3700d (Japan).

The test results of example 3 and comparative example 3 are shown in fig. 1. As can be seen from fig. 1, the dry and wet crockfastness of the fabric samples processed according to the invention are significantly improved with respect to the fastness levels achieved by the reference discharge process. Furthermore, as can be seen from fig. 1, the color intensity of the sample processed according to example 3 is more pronounced than the color intensity of the sample processed according to comparative example 3.

Example 4: discharge quality, definition and brightness

The fabric samples processed according to example 2.1, example 2.2 and the comparative fabric samples processed according to comparative examples 2.1 and 2.2 were compared for discharge quality, clarity and brightness. Visual inspection was performed on samples processed according to the present invention as shown in fig. 2a and samples processed according to known baseline methods and compositions as shown in fig. 2 b. The observations were as follows:

the white discharge sample processed according to example 2.1 showed significantly less yellowing than the white discharge sample processed according to comparative 2.1. The quality of discharge printing (i.e. bleaching) achieved with the composition and method according to the invention is thus improved over the known reference systems.

The color-discharged sample processed according to example 2.2 was identified as having a brighter color appearance than the color-discharged sample processed according to comparative example 2.2. The color brightness of the samples processed according to example 2.2 was improved over the reference samples. Without being bound by theory, it is believed that the compositions and printing methods according to the present invention produce less dye/pigment degradation than known baseline systems.

A clearer print pattern was observed for the white discharge and color discharge samples processed according to examples 2.1 and 2.2 compared to the samples processed according to comparative examples 2.1 and 2.2. Thus, the sharpness quality of the samples processed according to the invention is improved over the comparative samples.

Claims

1. A formaldehyde-free aqueous composition for discharge printing of fabrics, wherein the composition comprises

At least one of the two or more reducing agents,

at least one of the synthetic thickeners is used in the form of a liquid,

at least one of the wetting agents is used,

at least one of the pH-adjusting agents,

optionally at least one pigment, and

optionally at least one binder.

2. Composition according to claim 1, wherein the at least one synthetic thickener is a polyacrylic acid compound, preferably selected from acrylic acid copolymers, preferably comprising a high density oil and an auxiliary agent.

3. The composition of at least one of claims 1 or 2, wherein the at least one binder is based on a copolymer of two or more of poly (butyl acrylate), butyl (acrylate), ethyl (acrylate), and styrene, a polyethylene acrylate, acrylonitrile, or a mixture thereof.

4. A composition according to at least one of claims 1 to 3, wherein the wetting agent is selected from urea, glycerol or mixtures thereof.

5. The composition according to at least one of claims 1 to 4, wherein the reducing agent comprises or consists of a sulfinic acid derivative.

6. The composition according to at least one of claims 1 to 5, further comprising one or more components selected from the group of: a cross-linking agent, a softening agent, an emulsifying agent, a defoamer, a rheology modifier and an oxidation protectant or a mixture thereof.

7. The composition of at least one of claims 1 to 6, wherein the composition is free of any natural thickeners.

8. The composition of at least one of claims 1 to 7, wherein the composition comprises

3 to 30 wt% of at least one reducing agent,

0.05 to 6% by weight of at least one synthetic thickener,

3 to 45% by weight of at least one wetting agent,

0.05 to 4% by weight of at least one pH regulator,

0 to 30% by weight of at least one binder,

0 to 2% by weight of at least one emulsifier,

0 to 1% by weight of at least one defoamer,

0 to 3% by weight of at least one crosslinking agent,

0 to 3% by weight of at least one softener,

0 to 2% by weight of at least one rheology modifier,

0 to 2% by weight of at least one oxidation protecting agent,

0 to 6% by weight of at least one pigment dispersion,

the balance to 100 wt% being water,

wherein weight% is based on the total weight of the composition.

9. A process for the manufacture of a composition according to at least one of claims 1 to 8, comprising the following step a and optionally steps B and C:

step A: mixing and homogenizing all components of the composition according to at least one of claims 1 to 8, except for at least one pigment,

step C: the mixture obtained in step B is mixed and homogenized.

10. Use of the formaldehyde-free aqueous composition according to at least one of claims 1 to 8 or manufactured according to the method of claim 9 for a discharge printing process, in particular for a white discharge or color discharge printing process of textiles.

11. A discharge printing process for printing a fabric, the process comprising the steps of:

step 1: a colored fabric is provided which is a solid,

Step 2: and (3) printing: printing a fabric using the formaldehyde-free aqueous composition according to at least one of claims 1 to 8, or printing a fabric using the formaldehyde-free aqueous composition manufactured by the method according to claim 9,

step 3: a first drying step: the fabric obtained in step 2 is dried,

step 5: and a second drying step: drying the fabric obtained in step 4.

12. The method of claim 11, wherein the washing step comprises

a hot soaping step in which the printed fabric is washed with a soaping agent selected from soapy water at a temperature of 40 to 80 ℃, and/or,

13. The method according to at least one of claims 11 or 12, wherein the first drying step is performed at a temperature of 140 ℃ to 180 ℃, preferably 1 to 5 minutes, and/or wherein

The second drying step is carried out at a temperature of 120 to 160 ℃, preferably 8 to 20min.

14. The method according to at least one of claims 11 to 13, wherein the method does not comprise a curing step and or a steaming step.

15. Fabric treated with a composition according to at least one of claims 1 to 8 or obtained according to claim 9 in a discharge printing process according to at least one of claims 11 to 14.