Softener for denim fabric and use thereof

Abstract

The present application provides a softener for denim fabric and application thereof, the softener comprising a sulfonate-modified polyether polysiloxane block copolymer, an acid regulator and water; the sulfonate-modified polyether polysiloxane block copolymer is prepared by ring-opening copolymerization of terminal epoxy silicone oil and a modified amine component under heating, and the modified amine component is the reaction product of dodecylbenzenesulfonic acid and diethanolamine. The present application overcomes the defects of existing organic silicon softeners, such as poor stability, easy emulsion breaking, single hand feeling style, and difficulty in balancing fluffiness and hydrophilicity in the finishing process of denim fabric "heavy water washing, high electrolyte", and provides a modified organic silicon softener which can tolerate strong alkali and high salt environment while giving the fabric excellent fluffiness and hydrophilicity.

Description

Technical Field

[0001] This invention relates to the field of denim fabric technology, and more specifically to a softener for denim fabrics and its application. Background Technology

[0002] As a fashion and cultural symbol, denim clothing's unique style often relies on complex finishing processes, such as stone washing, enzyme washing, bleaching, and softening. With consumers' increasing demands for wearing experience, high-quality denim fabrics not only need excellent moisture absorption and breathability, but also require a very high level of hand feel—a comprehensive style that is both soft and crisp, smooth yet with a full and substantial feel (commonly referred to in the industry as "mushy" or "bouncy").

[0003] However, conventional silicone auxiliaries currently used in denim finishing generally suffer from a trade-off: traditional amino silicone oils, the most widely used softeners, while providing excellent smoothness, have three fatal flaws: first, they tend to feel "greasy" and "soft," lacking the fluffy, substantial feel required for denim; second, their hydrophobic nature leads to poor fabric moisture absorption, resulting in stuffy and hot wear; and third, the amino groups in their structure are highly susceptible to oxidation, causing severe yellowing in light-colored denim. Polyether-modified silicone oils, while solving the hydrophilicity and yellowing problems, still have drawbacks... Lacking active groups that can strongly interact with fibers, the finishing effect of traditional cation / quaternary ammonium salt modified silicone oils is often too dry and thin, failing to impart sufficient premium feel and softness to the fabric. To improve hydrophilicity, the industry has attempted to introduce quaternary ammonium salt groups into traditional cationic / quaternary ammonium salt modified silicone oils. However, existing synthesis processes often use benzyl chloride or short-chain quaternizing agents, resulting in emulsions with serious stability issues. This is particularly problematic in denim finishing processes, where large amounts of electrolytes (such as sodium sulfate) are typically added to prevent dye back-staining, and the washing solution is often alkaline. Under harsh conditions of high salt, high alkali, and high-temperature drying, traditional quaternary ammonium salt silicone oils are prone to demulsification and oil leaching, forming difficult-to-remove "silicone spots" on the fabric surface, causing significant economic losses. Summary of the Invention

[0004] This invention provides a softener for denim fabrics and its application, overcoming the shortcomings of existing silicone softeners in denim fabrics during "heavy washing and high electrolyte" finishing processes, such as poor stability, easy demulsification of silicone spots, and monotonous hand feel and style, making it difficult to achieve both fluffiness and hydrophilicity. It also provides a modified silicone softener that can impart excellent fluffiness and hydrophilicity to the fabric while being resistant to strong alkaline and high salt environments.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A softener for denim fabrics, the softener comprising the following components: (A) a sulfonate-modified polyether polysiloxane block copolymer; (B) an acidity modifier; and (C) water; wherein the component (A) the sulfonate-modified polyether polysiloxane block copolymer is prepared by a ring-opening copolymerization reaction of terminal epoxy silicone oil and a modified amine component under heating conditions; and the modified amine component is a reaction product of dodecylbenzenesulfonic acid and diethanolamine.

[0006] To achieve the above objectives, the present invention also provides the following technical solutions: The above-mentioned softener is used in the finishing of cotton fabrics, including all-cotton denim, polyester-cotton denim or stretch denim fabrics; the application method is impregnation or padding, and the treated fabric is dried and set at 170°C.

[0007] Compared with the prior art, the present invention has achieved the following beneficial effects: 1. This invention utilizes "large-volume anionic groups" to achieve a specific fluffy / full feel; This invention introduces dodecylbenzenesulfonate ions into the polysiloxane chain by reacting dodecylbenzenesulfonic acid (DBSA) with diethanolamine to generate a modified amine component. Unlike conventional small molecule acid ions (such as acetate and hydrochloride ions), dodecylbenzenesulfonate ions have a large hydrophobic long chain and a benzene ring structure. These large-volume side groups / counterions generate significant steric hindrance and internal plasticizing effects between polymer molecular chains, effectively preventing the excessively dense packing of siloxane segments and increasing the free volume of the molecular chains. This change in microstructure macroscopically manifests as giving denim fabric a thick, full, and elastic "flesh-like" feel, which is significantly different from the simple "slippery feel" of ordinary amino silicone oil or the "thin feel" of ordinary polyether silicone oil. 2. Construct a dual-stabilization system of "ammonium sulfonate salt-polyether" to solve the pain points of denim washing; This invention constructs a stable ammonium sulfonate structure in the molecular chain through the ring-opening reaction of secondary amines with epoxy groups and neutralization with strong acids. Compared with ammonium salts formed by traditional weak acids (acetic acid), sulfonates have a high degree of dissociation and strong binding force; at the same time, combined with hydrophilic polyether segments, a hydrophilic system with extremely strong self-emulsifying ability is formed. This structure endows the emulsion with excellent anti-electrolyte (salt resistance) and alkali resistance. In denim fabric treatment, even when faced with high concentrations of sodium sulfate (Glauber's salt) added for dye resistance and residual alkaline environments, the softener particles will not aggregate or break down. This completely solves the industry problem of traditional cationic silicone oils easily producing "silicone spots" and "oil floating" in denim dyeing vats. 3. Blocks amino oxidation, achieving high whiteness and instant hydrophilicity. Because the tertiary amine structure formed by diethanolamine is protected by protonation of strong sulfonic acid, the activity of amino groups being oxidized by air is greatly reduced, making the finished light-colored or bleached denim less prone to yellowing. At the same time, the synergistic effect of the block polyether segments and the ionic sulfonic acid groups enables the treated hydrophobic denim to become hydrophilic instantly, greatly improving wearing comfort. Attached Figure Description

[0008] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0009] Figure 1 This is a comparative schematic diagram of the denim fabric treated with the softener obtained in Embodiment 1 of the present invention and another denim fabric treated with the softener that has been publicly sold by the applicant; wherein, Figure 1 The left side shows the effect of the invention, and the right side shows the comparative effect. Detailed Implementation

[0010] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. It should be understood that the specific embodiments described herein are only for illustration and explanation of the present invention and are not intended to limit the present invention.

[0011] Any specific numerical value (including the endpoints of the numerical range) disclosed in this invention is not limited to the exact value, but should be understood to also cover values ​​close to the exact value, such as all possible values ​​within ±5% of the exact value. Furthermore, for the disclosed numerical range, one or more new numerical ranges can be obtained by arbitrarily combining the endpoint values ​​of the range, the endpoint values ​​with specific point values ​​within the range, and the specific point values. These new numerical ranges should also be considered as specifically disclosed in this invention.

[0012] The terminology used in this invention is for the purpose of describing specific exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “the” as used herein are intended to include the plural forms as well. The terms “comprising,” “including,” “containing,” and “having” are inclusive and thus describe the presence of said features, elements, compositions, steps, integers, operations, and / or components, but do not exclude the presence or inclusion of one or more other features, integers, steps, operations, elements, components, and / or sets thereof. Although the open-ended term “comprising” should be understood as a non-limiting term used to describe and claim the various embodiments described in this invention, in some aspects it may instead be understood as a more restrictive and limiting term, such as “consisting of” or “essentially composed of.” Thus, for any given embodiment describing a composition, material, component, element, feature, integer, operation, and / or process step, the invention also particularly includes embodiments consisting of or substantially consisting of such compositions, materials, components, elements, features, integers, operations, and / or process steps. In the case of “consisting of…”, the alternative embodiments exclude any additional compositions, materials, components, elements, features, integers, operations and / or process steps. In the case of “essentially composed of…”, any additional compositions, materials, components, elements, features, integers, operations and / or process steps that substantially affect the essential and novel characteristics are excluded from such embodiments. However, any compositions, materials, components, elements, features, integers, operations and / or process steps that do not substantially affect the essential and novel characteristics may be included in the embodiments.

[0013] Any method steps, processes, and operations described in this invention should not be construed as necessarily requiring them to be performed in the specific order discussed or shown, unless explicitly specified. It should also be understood that, unless otherwise stated, additional or alternative steps may be used.

[0014] In this invention, except where expressly stated, any matters or issues not mentioned are directly applicable to those known in the art without any modification. Furthermore, any embodiment described in this invention can be freely combined with one or more other embodiments described in this invention, and the resulting technical solutions or concepts are considered part of the original disclosure or original record of this invention, and should not be regarded as new content not disclosed or anticipated by this invention, unless those skilled in the art consider the combination to be clearly unreasonable.

[0015] Unless otherwise stated, the terminology used in this invention has the same meaning as commonly understood by those skilled in the art. If a term is defined in this invention and its definition differs from the common understanding in the art, the definition of this invention shall prevail.

[0016] As mentioned earlier, overcoming the shortcomings of existing silicone softeners in the "heavy washing, high electrolyte" finishing process of denim fabrics, such as poor stability, easy demulsification of silicone spots, and a lack of variety in hand feel and style, making it difficult to balance fluffiness and hydrophilicity, is a problem that the industry urgently needs to solve. In view of this, the present invention provides the following technical solution to solve the above problems.

[0017] First aspect

[0018] This invention provides a softener for denim fabrics, comprising the following components: (A) a sulfonate-modified polyether polysiloxane block copolymer; (B) an acidity modifier; and (C) water. Component (A), the sulfonate-modified polyether polysiloxane block copolymer, is prepared by a ring-opening copolymerization reaction of terminal epoxy silicone oil and a modified amine component under heating conditions. The modified amine component is a reaction product of dodecylbenzenesulfonic acid and diethanolamine. By introducing a specific modified amine component generated from the reaction of dodecylbenzenesulfonic acid and diethanolamine, a dodecylbenzenesulfonate anion with a large-volume hydrophobic long chain is introduced into the polysiloxane segment. The large-volume groups generate significant steric hindrance and internal plasticizing effects between molecular chains, achieving a unique fluffy, full, and elastic feel to denim fabric, which is known in the industry as "fleshy." At the same time, the formed ammonium sulfonate structure, combined with hydrophilic polyether segments, constructs a highly stable self-emulsifying system, thereby solving the defects of traditional amino silicone oil, such as greasy feel and easy yellowing, as well as the defects of ordinary cationic silicone oil, such as easy demulsification and silicone spots in high-salt and high-alkali washing processes for denim.

[0019] In some embodiments of the present invention, the modified amine component is prepared by mixing dodecylbenzenesulfonic acid and diethanolamine in a solvent at a molar ratio of 1:(1.0-1.3) and reacting at room temperature; the reaction mass ratio of the terminal epoxy silicone oil to the modified amine component is 100:(6.0-7.0); the ring-opening copolymerization reaction is carried out at 80°C for 6-8 hours. By strictly controlling the acid-amine molar ratio at 1:(1.0-1.3), it is ensured that dodecylbenzenesulfonic acid is completely neutralized to form a salt, avoiding residual strong acid corrosion of fabrics or equipment, and preventing excessive free amine from causing high-temperature yellowing of the finished product. By limiting the mass ratio of terminal epoxy silicone oil to modified amine components to 100:(6.0~7.0), precise control of the cationicity (charge density) and the proportion of hydrophilic groups in the polymer is achieved. This ensures excellent emulsion stability while solving the problems of insufficient improvement in feel due to too little modifier addition and increased cost and rough feel due to too much addition.

[0020] In some embodiments of the present invention, the terminal epoxy silicone oil is prepared by a hydrosilylation reaction between terminal hydrogen silicone oil and allyl glycidyl ether under the action of a catalyst; wherein the amount of allyl glycidyl ether added is such that the active hydrogen conversion rate in the terminal hydrogen silicone oil reaches more than 95%; the viscosity of the terminal hydrogen silicone oil is 40-900 cs, and the hydrogen content is 0.009-0.053%. By controlling the active hydrogen conversion rate to reach more than 95%, the safety hazard of residual active hydrogen in the system generating hydrogen gas during storage or use is eliminated, and crosslinking side reactions in subsequent reactions are prevented. At the same time, by limiting the viscosity of the terminal hydrogen silicone oil to 40-900 cs and the specific hydrogen content, the molecular weight of the final copolymer is preset, so that the softener molecules can effectively penetrate into the interior of cotton fibers (low viscosity advantage) and form a film on the fiber surface (high molecular weight advantage), thereby solving the problems of poor wash resistance due to too small molecular weight and poor penetration and oily surface due to too large molecular weight.

[0021] In some embodiments of the present invention, the terminal hydrogen silicone oil is prepared by an equilibrium reaction of octamethylcyclotetrasiloxane and tetramethyldihydrodisiloxane under the action of an acidic catalyst; wherein the mass ratio of octamethylcyclotetrasiloxane to tetramethyldihydrodisiloxane is 100:(0.67-3.48); the acidic catalyst is concentrated sulfuric acid, and the reaction temperature is 30°C. By precisely controlling the mass ratio of octamethylcyclotetrasiloxane to tetramethyldihydrodisiloxane to 100:(0.67-3.48), customized synthesis of the terminal hydrogen silicone oil chain length (i.e., the degree of polymerization of the siloxane backbone) is achieved. The silicone oil backbone length synthesized in this specific ratio is most compatible with the surface characteristics of denim fabric fibers, thereby maximizing the softness properties of organosilicon after subsequent grafting modification, and solving the problem of unstable final product feel (such as softness and resilience) caused by fluctuations in raw material ratios.

[0022] In some embodiments of the present invention, the weight parts of each component in the softener are as follows: (A) sulfonate-modified polyether polysiloxane block copolymer: 30 parts; (B) acidity regulator: 0.5-2.0 parts; (C) water: 70 parts. A high-concentration concentrated formulation system is constructed by using 30 parts of the high-solids copolymer combined with a specific ratio of acidity regulator and water. This formulation, while ensuring the long-term storage stability of the emulsion system, achieves the beneficial effect of reducing transportation and packaging costs, and simultaneously solves the problem of low-solids products requiring increased dosage and cumbersome operation due to insufficient effective ingredients in practical applications.

[0023] In some embodiments of the present invention, the acidity regulator is glacial acetic acid; the preparation method of the softener includes: adding component (B) to component (A) under stirring conditions and stirring until homogeneous, followed by slowly adding component (C) in batches for emulsification. By selecting glacial acetic acid as a co-solvent and protonating agent, and employing a phase-inversion emulsification process of "slowly adding water in batches," a smooth transition from water-in-oil (W / O) to oil-in-water (O / W) is achieved. This process ensures that the emulsion particles are small and uniformly distributed (appearing a bluish translucent appearance), thereby solving the technical problems of traditional one-time water addition processes that easily lead to excessively large emulsion particles, a milky white and opaque appearance, and easy stratification and oil drift upon standing. The aforementioned "batch" can specifically be any one of 3, 4, 5, 6, 7, 8, 9, or 10 times.

[0024] In some embodiments of the present invention, during the preparation of the modified amine component, the solvent is selected from one or more of isopropanol, ethylene glycol, and diethylene glycol; the diethanolamine is selected from industrial-grade diethanolamine with a purity greater than 98%. The use of alcohol solvents and high-purity (>98%) diethanolamine improves the compatibility of the reaction system through the coupling effect of the alcohol solvents, making the reaction more thorough. Furthermore, by controlling the purity of the raw materials, impurities that may lead to side reactions or the formation of chromophores are removed, thereby achieving a light-colored and highly transparent finished product. This solves the problem of low-purity raw materials causing the final softener product to turn yellow and affecting the whiteness of light-colored denim fabrics.

[0025] In some embodiments of the present invention, the allyl glycidyl ether is an allyl epoxy polyether, wherein the molar ratio of ethylene oxide to propylene oxide in the polyether segment is (6-8):(2-4). By limiting the molar ratio of ethylene oxide (EO) to propylene oxide (PO) in the polyether segment, the optimal balance between hydrophilicity and hand feel is achieved by utilizing the hydrophilicity provided by EO and the bulk hydrophobicity and softness provided by PO. This ratio ensures that the finished denim fabric has instant hydrophilicity while also using the PO segment to help improve the bulkiness, thereby resolving the contradiction between the sticky hand feel of pure EO segments and the poor hydrophilicity of pure PO segments.

[0026] In some embodiments of the present invention, the softener possesses the following physicochemical properties: resistance to 10 g / L sodium sulfate electrolyte at a concentration of 20 g / L, resistance to an alkaline environment with a pH of 10, and resistance to high-temperature treatment at 100°C without demulsification. Through a special sulfonate-modified molecular structure, the softener is endowed with extremely strong chemical stability, achieving stable existence under high-concentration electrolytes (sodium sulfate), strongly alkaline pH values, and high-temperature environments. This property directly addresses the harsh conditions present in denim fabric finishing processes (such as the high-salt environment introduced by anti-staining agents, residual alkali solutions, and high-temperature drying), thereby completely solving the industry pain point of ordinary softeners demulsifying and releasing silicone oil under such conditions, resulting in difficult-to-repair "silicone stains" on the fabric surface.

[0027] It is worth noting that, regarding the aforementioned "modified amine component," chemically, since the reaction between DBSA (acid) and diethanolamine (base) produces ammonium sulfonate salts, the essence of the aforementioned "modified amine component" is ammonium sulfonate salt.

[0028] Formula (A) below illustrates the reaction of octamethylcyclotetrasiloxane with tetramethyldihydrodisiloxane, i.e., the synthesis reaction of terminal hydrogen silicone oil. Formula (A) illustrates the process of preparing the raw material terminal hydrogen silicone oil by equilibration reaction of octamethylcyclotetrasiloxane and tetramethyldihydrodisiloxane under the action of an acidic catalyst (such as concentrated sulfuric acid).

[0029]

[0030] Formula (A) Formula (B) below illustrates the reaction between terminal hydrogen silicone oil and allyl glycidyl ether, i.e., the synthesis reaction of terminal epoxy silicone oil. Formula (B) shows the process by which terminal hydrogen silicone oil and allyl glycidyl ether undergo a hydrosilylation reaction in the presence of a platinum catalyst, introducing polyether segments and generating terminal epoxy silicone oil.

[0031]

[0032] Formula (B) Formula (C) below illustrates the reaction of dodecylbenzenesulfonic acid with diethanolamine to synthesize the modified amine component (ammonium sulfonate salt). Formula (C) demonstrates the process by which dodecylbenzenesulfonic acid and diethanolamine are mixed in a solvent in a specific ratio to generate a modified amine component with a bulky anionic structure.

[0033]

[0034] Formula (C) Formula (D) below illustrates the reaction between terminal epoxy silicone oil and modified amine components, namely the synthesis reaction of sulfonate-modified polyether polysiloxane block copolymer. Formula (D) shows the process by which the epoxy groups in the terminal epoxy silicone oil undergo a ring-opening copolymerization reaction with the modified amine components under heating conditions, ultimately generating a block copolymer (i.e., component A) with an ammonium sulfonate salt structure and polyether segments.

[0035]

[0036] Equation (D)

[0037] Second aspect The application of softeners in the finishing of cotton fabrics, as described in the first aspect, includes 100% cotton denim, polyester-cotton denim, or stretch denim fabrics. The application method is impregnation or padding, followed by drying and setting the fabric at 170°C. Applying a softener with this specific structure to denim fabric and drying it at 170°C utilizes high temperature to promote the directional alignment of molecular chains on the fiber surface and form a film, achieving a strong bond between the auxiliary agent and the fiber. This application method not only imparts excellent fluffiness, softness, and hydrophilicity to 100% cotton, polyester-cotton, and stretch denim fabrics, but also ensures the washability of the finishing effect, solving the problems of poor film formation and easy loss of hand feel during washing caused by low-temperature drying.

[0038] The present invention will be further described in detail below with reference to specific embodiments. These embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Example

[0039] Unless otherwise specified, the raw materials, equipment, materials and instruments used in this invention specification can all be obtained through general commercial channels.

[0040] Raw materials: Octamethylcyclotetrasiloxane D4 (Jiangxi Xinghuo Organosilicon), Tetramethyldihydrodisiloxane (Zhejiang Yingke New Materials), Allyl glycidyl ether AGE (Japan Daisaku), Linear dodecylbenzenesulfonic acid (96.5%, Linyi Lusen), Diethanolamine (analytical grade, Shangcheng Chemical), Isopropanol (analytical grade, Wuxi Jinko Chemical), Concentrated sulfuric acid (98%), Anhydrous sodium carbonate (analytical grade, Tianjin Fuchen), Potassium hydroxide (analytical grade, Tianjin Fuchen), Anhydrous sodium sulfate (analytical grade, Tianjin Fuchen), Acetic acid (99.5%, Shanghai Shenbo).

[0041] Equipment and Instruments: Digital display constant temperature electric heating mantle DRT-500S, JJ-1 precision timer stirrer, three-necked flask (Shuniu, 500ml), SHZ-(Ⅲ) circulating water multi-purpose vacuum pump, D-40 small rolling mill, R-3 shaping dryer, LS175 colorimeter (Linshang Technology), WSB-Ⅵ whiteness meter (Hangzhou Daji). Example 1

[0042] This embodiment provides a special softener for denim fabric, the preparation process of which includes the following steps: First, the synthesis of terminal hydrogen silicone oil is carried out. 100g of octamethylcyclotetrasiloxane, 1.68g of tetramethyldihydrodisiloxane and 3g of concentrated sulfuric acid are added to a four-necked flask equipped with a thermometer and a stirrer. Stirring is started, and timing is started when the temperature reaches 30°C. The reaction is continued for 5 hours. Then, 3.5g of soda ash is added for neutralization, and stirring is continued for 2 hours. After the reaction is completed, the mixture is filtered, and the product is put into a flask and heated to 140°C. Low-boiling substances are removed under vacuum until no liquid is extracted. The mixture is then cooled to obtain a terminal hydrogen silicone oil with a viscosity of 100-150 cs and a hydrogen content of 0.025%-0.027%. Subsequently, the terminal epoxy silicone oil was synthesized. 300g of the previously prepared terminal hydrogen silicone oil, 10.26g of allyl glycidyl ether (allyl epoxy polyether, EO to PO molar ratio of 6:4), and an appropriate amount of isopropanol were added to a reaction vessel. The mixture was heated and nitrogen gas was introduced. The temperature was raised to 60℃, and 3mg of isopropanol-chloroplatinic acid solution was added. The mixture was then heated to 80℃ and held for 3 hours. The active hydrogen conversion rate was found to be above 95%, yielding a transparent, viscous liquid, i.e., the terminal epoxy silicone oil. Simultaneously, the modified amine component was prepared. 100g of dodecylbenzenesulfonic acid and 60g of isopropanol were weighed into a container and stirred evenly at room temperature. 41.87g of diethanolamine (purity >98%) was slowly added dropwise at an acid-amine molar ratio of 1:1.3, controlled to be completed within 80 minutes. The mixture was then stirred at room temperature for another 3 hours, yielding a pale yellow, transparent liquid, the modified amine component. Next, a block copolymerization reaction was carried out. 100g of the terminal epoxy silicone oil, 6.84g of the modified amine component, and 50g of isopropanol were added to a reactor. Under nitrogen protection, the mixture was heated to 80°C and refluxed for 8 hours. Afterward, about 40g of isopropanol was distilled off, resulting in a pale yellow, transparent, viscous liquid, which is the sulfonate-modified polyether polysiloxane block copolymer. Finally, emulsification was performed. 30g of the block copolymer was added to 1g of glacial acetic acid and stirred at high speed until homogeneous. Then, 70g of deionized water was slowly added in 8 portions for phase inversion emulsification, resulting in a transparent, bluish, homogeneous emulsion, which is the denim fabric softener of this embodiment. Example 2

[0043] This embodiment provides a denim fabric softener with different molecular weight designs. Its preparation process is basically the same as in Example 1, except for the raw material ratio in the hydrogen-terminated silicone oil synthesis step. In this embodiment, the hydrogen-terminated silicone oil is synthesized using 100g of octamethylcyclotetrasiloxane, 3.48g of tetramethyldihydrodisiloxane, and 3g of concentrated sulfuric acid. The remaining reaction conditions remain unchanged. The resulting hydrogen-terminated silicone oil has a viscosity of 40–60 cs and a hydrogen content of 0.048%–0.053% (corresponding to a lower molecular weight). In the subsequent synthesis of the epoxy silicone oil, preparation of the modified amine component, block copolymerization reaction, and final emulsification step, the molar ratio of each reactant and the process parameters are consistent with those in Example 1, ultimately yielding the denim fabric softener of this embodiment. Example 3

[0044] This embodiment provides a denim fabric softener with different molecular weight designs. Its preparation process is basically the same as in Example 1, except for the raw material ratio in the hydrogen-silicone oil synthesis step. In this embodiment, the hydrogen-silicone oil is synthesized using 100g of octamethylcyclotetrasiloxane, 0.67g of tetramethyldihydrodisiloxane, and 3g of concentrated sulfuric acid. The remaining reaction conditions remain unchanged. The resulting hydrogen-silicone oil has a viscosity of 600–900 cs and a hydrogen content of 0.009%–0.011% (corresponding to a higher molecular weight). In the subsequent synthesis of epoxy silicone oil, preparation of the modified amine component, block copolymerization reaction, and final emulsification step, the molar ratio of each reactant and the process parameters are consistent with those in Example 1, ultimately yielding the denim fabric softener of this embodiment. Example 4

[0045] The only difference from Example 1 is that in the synthesis of the modified amine component in step (3), the molar ratio of dodecylbenzenesulfonic acid to diethanolamine is adjusted to 1:1.0 (i.e., equimolar reaction), that is, 100g of dodecylbenzenesulfonic acid and 32.21g of diethanolamine. The rest of the preparation process and feeding ratio are the same as in Example 1. Example 5

[0046] The only difference from Example 1 is that in step (4) of the synthesis of the block copolymer, the mass ratio of the terminal epoxy silicone oil to the modified amine component is adjusted to 100:6.0. The rest of the preparation process and feeding ratio are the same as in Example 1. Example 6

[0047] The only difference from Example 1 is that in the synthesis of the modified amine component in step (3), the molar ratio of dodecylbenzenesulfonic acid to diethanolamine is adjusted to 1:1.15, i.e., 100g of dodecylbenzenesulfonic acid and 37.04g of diethanolamine. The rest of the preparation process and feeding ratio are the same as in Example 1. Comparative Example 1

[0048] The comparative example uses the quaternary ammonium salt modified silicone oil "Cotton Hydrophilic Soft Silicone Oil CCR853" previously publicly sold by the applicant as a comparative sample, which appears as a blue transparent color. Comparative Example 2

[0049] The preparation method of this comparative example is basically the same as that of Example 1, except that in the synthesis of the modified amine component in step (3), equimolar amounts of glacial acetic acid are used instead of dodecylbenzenesulfonic acid. That is, glacial acetic acid is used to react with diethanolamine to generate conventional ammonium acetate, which then participates in the subsequent copolymerization reaction. Finally, acetate-modified polyether polysiloxane softener is obtained. Comparative Example 3

[0050] The preparation method of this comparative example is basically the same as that of Example 1. The only difference is that in the preparation of the softener emulsion in step (5), 70g of deionized water is added to the stirred block copolymer at once, instead of being added in portions.

[0051] Performance Tests and Results To verify the technical effect of the present invention, the softener prepared in Example 1 was compared with that in Comparative Example 1 in terms of physicochemical properties and application effect.

[0052] In the physicochemical stability tests, the softener was placed under different harsh conditions to observe its state: In the high-temperature resistance test (heating at 100℃), the shear resistance test (3000rpm×30min), and the anion resistance test (with 1.5g / L of fluorescent whitening agent VBL added), Example 1 showed stability without demulsification. In the salt and alkali resistance tests, the emulsion of Example 1 remained stable at 60℃ with 10g / L sodium sulfate added, or under alkaline conditions at pH=10 (60℃) and pH=11 (room temperature), without demulsification or oil separation. In contrast, Comparative Example 1 showed slight oil separation at pH=10 (60℃), demulsified and separated at pH=11 (room temperature), and could only tolerate 1g / L of VBL.

[0053] In the application effect test, three fabrics were selected: 100% cotton denim, polyester-cotton denim, and cotton-spandex stretch denim. An immersion process (3% owf, immersion for 20 minutes, drying at 170℃ for 90 seconds) was used for finishing. The hand feel scores (out of 5, 5 being the best) showed that the three fabrics treated in Example 1 scored 5, 4.8, and 4.8 respectively, exhibiting significant fluffiness and fullness; while the scores for the fabrics treated in Comparative Example 1 were 4, 4.2, and 4.2, indicating a relatively poor hand feel.

[0054] The hydrophilicity test results (AATCC79 standard) showed that the water droplet diffusion times of the three fabrics treated in Example 1 were 5 seconds, 4.8 seconds, and 4.8 seconds, respectively, achieving instant hydrophilicity; while the hydrophilicity times of the fabrics treated in Comparative Example 1 were 10 seconds, 9 seconds, and 10 seconds. Furthermore, the yellowing test results (HG / T4734 standard) showed that the yellowing value ΔW of the fabric treated in Example 1 was only 0.5, far lower than the 1.0 of Comparative Example 1. The comprehensive test results indicate that the softener prepared in this invention is significantly superior to Comparative Example 1 in terms of stability, fluffy feel, hydrophilicity, and resistance to yellowing.

[0055] Table 1. Evaluation of the feel of each embodiment and comparative example of the present invention.

[0056] The water droplet diffusion time was tested according to the requirements of the hydrophilic time determination standard HG / T 4917-2016.

[0057] Table 2 Hydrophilicity Test

[0058] Under different pH conditions and with different inorganic salt interference, the emulsion was left to stand for 24 hours, and the changes in the state of the emulsion were observed.

[0059] Table 3 Stability Test

[0060] According to the requirements of the fabric yellowing test standard HG / T 4734-2014, the yellowing value ΔW is tested.

[0061] Table 4 Yellowing Resistance Test

[0062] Furthermore, the softeners prepared in Examples 4-6 (different ratios) and Comparative Examples 2-3 (different raw materials or processes) were tested under the same conditions.

[0063] 1. Verification of the ratio range (Examples 4-6): The test results showed that although the softener prepared in Example 4 (acid-amine ratio 1:1.0) had good stability, the fabric was slightly yellow after high-temperature drying (ΔW=0.9). This may be due to the lack of buffer protection from excess amine, but it is still within the acceptable range. The hand feel score of Example 5 (reaction ratio 100:6.0) was slightly lower than that of Example 1 (5 points, 4.8 points, 4.8 points), and the hydrophilicity time was 6 seconds, 7 seconds, and 6.5 seconds, indicating that the reduction in the content of modified groups had a slight impact on the performance, but it was still significantly better than Comparative Example 1.

[0064] 2. Core Raw Material Verification (Comparative Example 2 - Acetic Acid as a Substitute for DBSA): The sample prepared in Comparative Example 2 appeared as a transparent emulsion, but performed poorly in stability testing: significant turbidity (a precursor to demulsification) appeared at 60℃ and 10g / L sodium sulfate, and complete demulsification occurred at pH=11. More importantly, the finished denim fabric received hand feel scores of 4.3, 4.5, and 4.3, with a style leaning towards "soft and smooth," completely lacking the "fluffy and full" feel (fleshy texture) characteristic of Example 1 (5, 4.8, and 4.8). This result strongly demonstrates that the use of dodecylbenzenesulfonic acid (DBSA) in this invention is not a simple acid-base neutralization, but rather utilizes the steric hindrance effect and internal plasticizing effect generated by its large-volume hydrophobic long chain to give denim fabric a unique fluffy style, which cannot be achieved by conventional small-molecule acids (such as acetic acid).

[0065] 3. Process Validation (Comparative Example 3 - Single Water Addition): Comparative Example 3 failed to achieve phase inversion during emulsification, and the final product was a milky white coarse dispersion. After standing for 24 hours, obvious stratification and oil floating phenomena appeared. This indicates that for the sulfonate-modified high-viscosity polymer system of this invention, the phase inversion emulsification process of "multiple water additions" is the key step in preparing stable microemulsions.

[0066] The softener prepared in Example 4 (acid-amine ratio 1:1.0) remained stable in stability tests at 60°C with 10 g / L sodium sulfate added, or under alkaline conditions at pH=10 (60°C) and pH=11 (room temperature). In anionic resistance tests, it remained stable in a 2.0 g / L solution of fluorescent whitening agent VBL, demonstrating better stability than Example 1. However, in hand feel tests, the softener in Example 4 scored only 4.3, 4.5, and 4.3 on the three fabrics, lower than Example 1; its hydrophilicity time was approximately 5 s, 4.5 s, and 4.5 s, similar to Example 1; and after high-temperature drying, the yellowing value of the fabric (ΔW=0.9) was slightly higher than Example 1.

[0067] The softener prepared in Example 5 (reaction ratio 100:6.0) showed similar stability to that of Example 1, but its hand feel test scores were 4.5, 4.5, and 4.5, slightly lower than that of Example 1. Its hydrophilicity time was 6s, 7s, and 6.5s, slightly slower than that of Example 1. After high-temperature drying, the yellowing value of the fabric was ΔW=0.5. Although the hand feel and hydrophilicity time were slightly lower than those of Example 1, they were still within acceptable limits.

[0068] The softener prepared in Example 6 (acid-amine ratio 1:1.15) showed similar stability indices to that of Example 1. Its hand feel test scores were 4.7, 4.5, and 4.8, slightly lower than Example 1 but close to those of Example 5. The hydrophilicity test times were 5s, 4.5s, and 5s, and the fabric yellowing value ΔW=0.8, higher than Example 1 and consistent with the trend of Example 4. Although the effects of Examples 4, 5, and 6 were slightly lower than Example 1, they were still superior to Comparative Example 1.

[0069] The above data shows that the numerical range (acid-amine ratio 1.0-1.3, mass ratio 6.0-7.0) defined by the present invention is a scientifically verified reasonable range.

[0070] These are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims. Furthermore, specific examples have been used in the specification to illustrate the principles and implementation methods of the present invention. The above description of the embodiments is only for the purpose of helping to understand the method and core ideas of the present invention, and the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A softener for denim fabrics, characterized in that, The softener comprises the following components: (A) Sulfonate-modified polyether polysiloxane block copolymer; (B) Acidity regulators; (C) Water; The sulfonate-modified polyether polysiloxane block copolymer of component (A) is prepared by ring-opening copolymerization of terminal epoxy silicone oil and modified amine component under heating conditions; The modified amine component is the reaction product of dodecylbenzenesulfonic acid and diethanolamine; The modified amine component is prepared by mixing dodecylbenzenesulfonic acid and diethanolamine in a solvent at a molar ratio of 1:(1.0-1.3) and reacting at room temperature. The reaction mass ratio of the terminal epoxy silicone oil to the modified amine component is 100:(6.0~7.0); The ring-opening copolymerization reaction was carried out at a temperature of 80°C for 6–8 hours. The terminal epoxy silicone oil is prepared by hydrosilylation reaction of terminal hydrogen silicone oil and allyl glycidyl ether under the action of a catalyst. The terminal hydrogen silicone oil is prepared by an equilibrium reaction of octamethylcyclotetrasiloxane and tetramethyldihydrodisiloxane under the action of an acidic catalyst. The mass ratio of octamethylcyclotetrasiloxane to tetramethyldihydrodisiloxane is 100:(0.67-1.68); the preparation method of the softener includes: adding component (B) to component (A) and stirring evenly under stirring conditions, and then slowly adding component (C) in batches for emulsification.

2. The softener as described in claim 1, characterized in that, The amount of allyl glycidyl ether fed in the feed results in an active hydrogen conversion rate of over 95% in the terminal hydrogen silicone oil. The viscosity of the hydrogen-terminated silicone oil is 40–900 cs, and the hydrogen content is 0.009–0.053%.

3. The softener as described in claim 2, characterized in that, The acidic catalyst is concentrated sulfuric acid, and the reaction temperature is 30°C.

4. The softener as described in claim 1, characterized in that, The weight proportions of each component in the softener are as follows: (A) Sulfonate-modified polyether polysiloxane block copolymer: 30 parts; (B) Acidity regulator: 0.5–2.0 parts; (C) Water: 70 parts.

5. The softener as described in claim 4, characterized in that, The acid regulator is glacial acetic acid.

6. The softener as claimed in claim 1, characterized in that, In the preparation of the modified amine component, the solvent is selected from one or more of isopropanol, ethylene glycol, and diethylene glycol; The diethanolamine is selected from industrial-grade diethanolamine with a purity greater than 98%.

7. The softener as described in claim 2, characterized in that, The allyl glycidyl ether is an allyl epoxy polyether, and the molar ratio of ethylene oxide to propylene oxide in its polyether segment is (6-8):(2-4).

8. The softener according to any one of claims 1 to 7, characterized in that, The softener has the following physicochemical properties: it is resistant to 10 g / L sodium sulfate electrolyte at a concentration of 20 g / L, resistant to an alkaline environment with a pH of 10, and resistant to high-temperature treatment at 100°C without demulsification.

9. The application of the softener as described in any one of claims 1 to 8 in the finishing of cotton fabrics, characterized in that, The cotton fabrics include all-cotton denim, polyester-cotton denim, or stretch denim fabrics. The application method is impregnation or padding, and the treated fabric is dried and set at 170°C.

Images