A fluorine-free water repellent finishing agent modified with silicone and a preparation method thereof

Abstract

The application discloses a fluorine-free water-proof finishing agent modified by silicone and a preparation method thereof, wherein the preparation raw materials comprise modified acrylate, blocked isocyanate, acrylate monomer, emulsifier, initiator, organic solvent and water, and the preparation raw materials of the modified acrylate comprise amino silicone oil and glycidyl methacrylate. The fluorine-free water-proof finishing agent modified by silicone can effectively improve the hand feeling of the finished textile, forms a flexible coating when the finishing agent is formed into a film on the surface of the fabric, and enables the cotton fabric to have soft and smooth touch, thereby meeting the demand of consumers on the wearing comfort of the textile.

Description

Technical Field

[0001] This application relates to the field of fabric finishing agents, specifically to an organosilicon-modified fluorine-free waterproof finishing agent and its preparation method. Background Technology

[0002] With the development of the social economy and the upgrading of consumer demand, the multi-functionality of textiles has become an important development direction for the textile industry. Among them, waterproof textiles have a broad market application space because they can meet the needs of daily protection and outdoor wear. In the process of waterproof finishing textiles, the performance of the waterproof finishing agent is the core factor determining the waterproof effect of the final product. At the same time, the type and structure of textiles and the post-processing conditions also have a certain impact on waterproof performance. Therefore, the development of high-performance waterproof finishing agents has always been a key focus of industry research.

[0003] Currently, commonly used waterproofing agents for textiles mainly include fluorinated, silicone, acrylic, and polyurethane types. Among them, fluorinated waterproofing agents, due to the excellent crystallinity of carbon-fluorine bonds, can form a low surface energy layer on the surface of textiles, thus achieving good waterproofing effects, and were once widely used in the market. However, during the production and use of fluorinated waterproofing agents, substances such as perfluorooctane sulfonate and perfluorooctanoic acid (PFOA) are easily generated, which are harmful to human health and the ecological environment. These substances are bioaccumulative and persistent, causing long-term pollution to water bodies, soil, and other environments, and may also pose potential hazards to human health through contact. Therefore, the use of fluorinated waterproofing agents has been strictly restricted by many domestic and international environmental regulations and is gradually being phased out of the mainstream application market.

[0004] To replace fluorinated waterproofing agents, the industry has begun to focus on the research and development of fluorine-free waterproofing agents, aiming to develop environmentally friendly alternatives. However, existing fluorine-free waterproofing agents still have significant shortcomings in practical applications: on the one hand, textiles treated with most fluorine-free waterproofing agents tend to be stiff and lack softness, affecting wearing comfort and failing to meet consumers' demands for the feel of textiles; on the other hand, their waterproofing performance has poor durability, and the waterproofing effect decreases significantly after multiple washes, failing to maintain its protective function for a long time. This greatly limits the widespread application of fluorine-free waterproofing agents. Therefore, the industry urgently needs to develop a fluorine-free waterproofing agent that is both fluorine-free and environmentally friendly, imparts a soft feel to textiles, and possesses excellent waterproofing performance and high wash fastness, in order to address the shortcomings of existing technologies and promote green and sustainable development in the field of textile waterproofing finishing. Summary of the Invention

[0005] The purpose of this application is to provide a fluorine-free waterproof finishing agent and its preparation method.

[0006] To achieve the above objectives, the technical solution adopted in this application is as follows: a silicone-modified fluorine-free waterproof finishing agent is provided, the raw materials for preparation include modified acrylate, capped isocyanate, acrylate monomer, emulsifier, initiator, organic solvent and water, wherein the raw materials for preparation of the modified acrylate include amino silicone oil and glycidyl methacrylate.

[0007] As a preferred embodiment, the modified acrylate is prepared by mixing the amino silicone oil and glycidyl methacrylate and heating to 100-120 °C.

[0008] As a preferred embodiment, the method for preparing the capped isocyanate is as follows: mixing the capping agent with an active isocyanate monomer and heating the mixture to react for a period of time to obtain the capped isocyanate.

[0009] As a preferred embodiment, the capping agent is any one or a combination of multiple of acetone oxime, butanone oxime, cyclohexanone oxime, ξ-caprolactam, 3,5-dimethylpyrazole, KHSO3, NaHSO3, 1,2,4-triazole, and nonylphenol.

[0010] As a preferred embodiment, the active isocyanate monomer is Wherein R is a C2-C22 linear or branched alkyl group; or, the active isocyanate monomer is R1 is a C2-C18 branched chain or branched alkyl group; or, the active isocyanate monomer is... R2 is a C2-C22 linear or branched alkyl group; or the active isocyanate monomer is R3 is a C2-C22 linear or branched alkyl group.

[0011] As a preferred embodiment, the acrylate monomer includes long-chain acrylates and short-chain acrylates, wherein the long-chain acrylates contain at least 12 alkyl carbons and the short-chain acrylates contain at least 8 alkyl carbons.

[0012] As a preferred embodiment, the long-chain acrylate is one or a mixture of more of the following: lauryl acrylate, hexadecyl acrylate, hexadecyl methacrylate, octadecyl acrylate, octadecyl methacrylate, docosyl acrylate, docosyl methacrylate, and 2-methyl-2-octadecyl acrylate; and the short-chain acrylate is one or a mixture of more of the following: methyl acrylate, methyl methacrylate, ethyl acrylate, n-butyl acrylate, and isooctyl acrylate.

[0013] As a preferred embodiment, the emulsifier is one or more of the following: cashew phenol polyoxyethylene polyoxypropylene ether, linear fatty alcohol polyoxyethylene ether, branched fatty alcohol polyoxyethylene ether, branched fatty alcohol polyoxyethylene polyoxypropylene ether, fatty amine polyoxyethylene ester, and fatty acid polyoxyethylene ester; the initiator is one or more of the following: ammonium persulfate, benzoyl peroxide, di-tert-butyl peroxide, dicumyl peroxide, tert-butyl hydroperoxide, sodium persulfate, potassium persulfate, azobisisobutyronitrile, azobisisobutyramidine hydrochloride, and azobisisoheptanenitrile.

[0014] This application also provides a method for preparing a silicone-modified fluorine-free waterproof finishing agent, comprising the following preparation steps: S1: mixing amino silicone oil with glycidyl methacrylate and heating to obtain a modified acrylate; mixing a capping agent with an active isocyanate monomer and heating to react to obtain a capped isocyanate; S2: mixing the modified acrylate, the capped isocyanate, acrylic monomer, emulsifier, organic solvent and water, and subjecting the mixture to high-speed shearing and homogenization to obtain a pre-emulsion; S3: heating the pre-emulsion and adding an initiator, and continuously maintaining the temperature for a period of time to obtain the silicone-modified fluorine-free waterproof finishing agent.

[0015] As another preferred embodiment, in step S1, the amino silicone oil and the glycidyl methacrylate are heated and reacted at 100~120 °C for 30~60 min, and the end-capping agent and the active isocyanate monomer are reacted at 60~80 °C for 1~2 hours; in step S3, when the pre-emulsion is heated to 55~60 °C, an initiator is added, and then the reaction is continued at this temperature for 3~6 hours to obtain the organosilicon-modified fluorine-free waterproof finishing agent.

[0016] Compared with the prior art, the beneficial effects of this application are as follows: (1) The organosilicon-modified fluorine-free waterproof finishing agent of this application does not contain fluorine, thus avoiding the problem of fluorine-containing finishing agents generating substances that are harmful to human health and the ecological environment and have bioaccumulation and persistence during production and use. It meets the requirements of environmental protection regulations, is environmentally friendly, and helps the green and sustainable development of the textile waterproof finishing field. (2) The organosilicon-modified fluorine-free waterproof finishing agent of this application can effectively improve the hand feel of textiles after finishing. The polysiloxane backbone of amino silicone oil gives the molecular chain excellent flexibility, so that the finishing agent forms a flexible coating when it forms a film on the fabric surface, giving cotton fabric a soft and smooth feel. At the same time, the short-chain acrylate further enhances the adhesion and softness of the film layer, meeting consumers' needs for the comfort of wearing textiles. (3) The organosilicon-modified fluorine-free waterproof finishing agent of this application has excellent waterproof performance and wash fastness. The low surface energy characteristics of organosilicon segments form a hydrophobic layer on the fabric surface. The active groups released after the end-capped isocyanate is decapped at high temperature can react with the groups on the fabric surface to form stable chemical bonds, firmly anchoring the finishing agent to the fiber surface. It can also form a three-dimensional network cross-linked structure with other components to reduce water molecule penetration. Even after multiple washes, it can still maintain a good waterproof effect and ensure the long-term protective function of the fabric. Detailed Implementation

[0017] The present application will be further described below with reference to specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0018] The terms “comprising” and “having”, and any variations thereof, in the specification and claims of this application are intended to cover non-exclusive inclusion, for example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product, or device.

[0019] This application provides a silicone-modified fluorine-free waterproof finishing agent, the raw materials of which include: modified acrylate, capped isocyanate, acrylate monomer, emulsifier, initiator, organic solvent, and water. After treatment of cotton fabrics, the silicone-modified fluorine-free waterproof finishing agent of this application is suitable for cross-linking on the surface of cotton fabrics, firmly adhering to the cotton fabric without affecting the hand feel, while exhibiting good waterproof effect and high wash fastness.

[0020] The modified acrylate described in this application refers to the modified glycidyl methacrylate prepared by modifying glycidyl methacrylate with amino silicone oil. A method for preparing the modified acrylate is provided: amino silicone oil and glycidyl methacrylate are mixed and heated to obtain the modified acrylate.

[0021] This application prepares modified acrylates by chemically bonding the organosilicon structure of amino silicone oil with the acrylate skeleton of glycidyl methacrylate. The introduction of amino silicone oil introduces reactive sites into the finishing agent. The amino groups in the molecule and the epoxy groups of glycidyl methacrylate form strong chemical bonds through high-temperature ring-opening reaction, so that the organosilicon segments are uniformly distributed in the polymer molecules. This not only retains the film-forming properties of acrylate finishing agents, but also lays the foundation for the subsequent construction of a hydrophobic layer on the surface of cotton fabrics by taking advantage of the low surface energy characteristics of organosilicon segments. At the same time, it avoids the defects of small molecule organosilicon additives such as easy migration and functional failure.

[0022] Regarding improved hand feel, the polysiloxane backbone of amino silicone oil features large bond angles and low rotational energy barriers, endowing the molecular chain with excellent flexibility. When the finishing agent forms a film on the surface of cotton fabric, the organosilicon segments can form a flexible coating on the fiber surface, giving the finished cotton fabric a soft and smooth feel. In terms of enhanced waterproof performance and durability, the low surface energy characteristics of the organosilicon segments in the modified acrylate construct a hydrophobic layer on the surface of cotton fabric, further reducing the fabric's surface energy and improving the initial waterproof effect.

[0023] Preferably, the amino silicone oil is one or a combination of amino polydimethylsiloxane, aminopropyl polydimethylsiloxane, amino polymethylsiloxane or amino polytetramethylsiloxane.

[0024] In this application, capped isocyanate refers to an active isocyanate monomer capped by a capping agent. This application provides a method for preparing capped isocyanate: the capping agent and the active isocyanate monomer are mixed and heated to react for a period of time to obtain the capped isocyanate.

[0025] In some preferred embodiments, the capping agent is any one or a combination of multiple of acetone oxime, butanone oxime, cyclohexanone oxime, ξ-caprolactam, 3,5-dimethylpyrazole, KHSO3, NaHSO3, 1,2,4-triazole, and nonylphenol.

[0026] From the perspectives of environmental protection and cost, the preferred end-capping agents are 3,5-dimethylpyrazole and NaHSO3.

[0027] In some embodiments, the active isocyanate monomer is , where R is a C2-C22 linear or branched alkyl group.

[0028] In some embodiments, the active isocyanate monomer is R1 is a C2-C18 branched chain or branched alkyl group.

[0029] In some embodiments, the active isocyanate monomer is , where R2 is a C2-C22 linear or branched alkyl group.

[0030] In some embodiments, the active isocyanate monomer is R3 is a C2-C22 linear or branched alkyl group.

[0031] In a preferred embodiment, the active isocyanate monomer is Or a mixture thereof.

[0032] This application utilizes a capping agent to transform highly reactive -NCO groups into stable, closed structures. The chemical bonds formed between the capping agent and the -NCO groups are not easily broken at room temperature, preventing premature reactions between the reactive isocyanate monomers and water or other reactive groups such as amino groups in the fluorine-free waterproofing finishing agent system. This effectively prevents gelation and delamination of the fluorine-free waterproofing finishing agent during storage. Simultaneously, the capped isocyanate maintains good compatibility with other components, laying the foundation for uniform film formation when using the fluorine-free waterproofing finishing agent, and solving the industry problem of isocyanate-based finishing agents easily failing.

[0033] This application prepares a capped isocyanate that decomposes during high-temperature baking, releasing an active -NCO group. This group reacts with residual hydrophilic components on the fabric surface, converting them into a hydrophobic structure. This reduces the hydrophilic sites on the surface of the cotton fabric from the source, preventing water molecules from penetrating into the fabric due to the adsorption of the hydrophilic group.

[0034] Secondly, the released active -NCO groups react with the hydroxyl groups on the surface of the cotton fabric to form stable chemical bonds, firmly anchoring the fluorine-free waterproof finishing agent to the fiber surface and preventing it from falling off. This allows the hydrophobic coating to adhere tightly to the fiber, reducing water penetration on the fiber surface.

[0035] When the organosilicon-modified fluorine-free waterproofing agent of this application forms a film on cotton fabric, it utilizes ionic bonds to bond with the cotton fabric through Coulomb forces, and silane bonds to crosslink with the hydroxyl groups on the cotton fabric, allowing the fluorine-free waterproofing agent to firmly adhere to the fabric. The capped isocyanate in the system has active groups that decapsulate and crosslink at high temperatures, consuming the hydrophilic substances on the surface of the cotton fabric while enhancing the bonding strength between the hydrophobic polymer and the fiber, thus improving the waterproof performance and durability of the fluorine-free waterproofing agent. Textiles treated with the organosilicon-modified fluorine-free waterproofing agent of this application can resist a range of water sources in the external environment, such as rainwater and snowmelt. Furthermore, the introduction of the organosilicon structure makes the textiles softer, improving their wearing comfort.

[0036] The acrylate monomers of this application are a mixture of long-chain acrylates and short-chain acrylates, wherein the number of alkyl carbons in the long-chain acrylates is not less than 12, and the number of alkyl carbons in the short-chain acrylates is not more than 8.

[0037] In some embodiments, the long-chain acrylate is one or a mixture of more than one of lauryl acrylate, hexadecyl acrylate, hexadecyl methacrylate, octadecyl acrylate, octadecyl methacrylate, docosyl acrylate, docosyl methacrylate, and 2-methyl-2-octadecyl acrylate.

[0038] In some embodiments, the short-chain acrylate is one or a mixture of more than one of methyl acrylate, methyl methacrylate, ethyl acrylate, n-butyl acrylate, and isooctyl acrylate.

[0039] This application mixes long-chain acrylates with short-chain acrylates. The long-chain acrylates cause the alkyl side chains in the prepared fluorine-free waterproofing agent to crystallize, thereby reducing the activity of the side chains. When these side chains come into contact with aqueous solutions, the chain segments do not remodel, resulting in a stable dynamic surface tension and durable low surface energy on the surface of the fluorine-free waterproofing agent. The short-chain acrylates lower the glass transition temperature of the fluorine-free waterproofing agent, thereby increasing the adhesion and softness of the film formed on the fabric surface.

[0040] The long alkyl side chains of long-chain acrylates not only have a hydrophobic crystalline structure, but also reduce the penetration and swelling of water molecules into the film layer during washing, preventing the film layer from softening and peeling off due to washing water. At the same time, the intermolecular forces between long chains are stronger, making it less prone to chain segment breakage due to mechanical friction during washing, thus maintaining the structural integrity of the film layer. Short-chain acrylates, by lowering the glass transition temperature, result in a more flexible film layer during film formation, which can deform synchronously with the slight deformation of the fabric fibers, preventing the film layer from cracking and peeling off due to excessive rigidity.

[0041] If only short-chain acrylates are used, although the feel is soft, the resulting waterproof membrane may stick together due to excessive toughness, and the waterproof performance will be greatly reduced due to the lack of a crystalline skeleton. The crystalline structure of long-chain acrylates can form support points in the soft membrane, which can retain the softness brought by short-chain acrylates and maintain the morphological stability of the membrane, thus achieving the effect of a soft feel after the fabric is treated with fluorine-free waterproof finishing agent.

[0042] Furthermore, the active end groups of long-chain acrylates are suitable for reacting with the active -NCO groups released by the capped isocyanate. The active -NCO groups simultaneously crosslink with the hydroxyl and amino groups in the modified acrylate, forming a three-dimensional network crosslinked structure on the surface of the cotton fabric. This structure helps to lock the hydrophobic alkyl segments of the long-chain acrylate, making them evenly distributed in the membrane layer. It also improves the compactness of the hydrophobic membrane through crosslinking, further reducing the porosity of the membrane layer and reducing the permeation of water molecules.

[0043] In some embodiments, the emulsifier is one or more of the following: cashew phenol polyoxyethylene polyoxypropylene ether, linear fatty alcohol polyoxyethylene ether, branched fatty alcohol polyoxyethylene ether, branched fatty alcohol polyoxyethylene polyoxypropylene ether, fatty amine polyoxyethylene ester, and fatty acid polyoxyethylene ester.

[0044] Emulsifiers form a stable monomolecular film at the oil-water interface through directional adsorption, significantly reducing interfacial tension and allowing the oil phase components to be uniformly dispersed into tiny droplets, ultimately forming a homogeneous emulsion. This also helps the emulsion maintain a stable state during storage and use.

[0045] In some embodiments, the initiator is one or more of the following: ammonium persulfate, benzoyl peroxide, di-tert-butyl peroxide, dicumyl peroxide, tert-butyl hydroperoxide, sodium persulfate, potassium persulfate, azobisisobutyronitrile, azobisisobutyramidine hydrochloride, and azobisisoheptanenitrile.

[0046] The initiator will decompose under specific temperature conditions to generate active free radicals, triggering the polymerization between the components in the organosilicon-modified fluorine-free waterproof finishing agent. The modified acrylate, acrylate monomer, and capped isocyanate all contain polymerizable double bonds, which require active free radical initiation to form long-chain polymers. The initiator is suitable for efficiently decomposing to generate free radicals. These free radicals can quickly attack the monomer double bonds, triggering chain growth reactions, so that the monomers combine in the designed proportion to form the fluorine-free polymer backbone.

[0047] Initiators also help control the polymerization process smoothly, preventing excessively rapid decomposition from causing violent reactions and sudden temperature rises, and also preventing excessively slow decomposition from leading to excessively long reaction cycles and low efficiency. This controllability avoids problems such as over- or under-crosslinking of polymers due to runaway reactions, while also reducing the generation of byproducts.

[0048] In some embodiments, the organic solvent is one or more of ethanol, diethyl ether, methanol, acetone, isopropanol, tetrahydrofuran, ethylene glycol, propylene glycol, dipropylene glycol, and tripropylene glycol.

[0049] The organosilicon-modified fluorine-free waterproofing agent prepared in this application has an organosilicon structure, and the long-chain acrylate crystallizes, reducing the activity of the chain segments and preventing chain segment reconstruction, thus achieving excellent waterproofing performance. Simultaneously, when this organosilicon-modified fluorine-free waterproofing agent treats cotton fabrics, the silane bonds crosslink with the hydroxyl groups on the cotton fabric, and the capped isocyanates in the system de-capture and crosslink at high temperatures. This consumes the hydrophilic substances on the fabric surface while enhancing the bonding strength between the hydrophobic polymer and the fiber, improving the waterproofing performance and durability of the organosilicon-modified fluorine-free waterproofing agent. The organosilicon structure also imparts a soft hand feel to the fabric, improving the comfort of wearing the textiles.

[0050] The organosilicon-modified fluorine-free waterproofing agent of this application is prepared by emulsion polymerization of modified acrylate, end-capped isocyanate, acrylic monomer and emulsifier. It organically combines the characteristics of different components to achieve a synergistic effect and can achieve good waterproof performance on cotton fabrics.

[0051] In some embodiments, the emulsion particle size of the silicone-modified fluorine-free waterproofing finishing agent of this application is 100~400 nm, and the emulsion surface potential is +40~+50 mV. Emulsion particles of 100~400 nm are suitable for filling tiny gaps on the fiber surface, avoiding discontinuous film due to excessively large particles or agglomeration due to excessively small particles. The positive potential of +40~+50 mV can prevent particles from agglomerating into large particles during storage or application, ensuring a uniform film formation effect while maintaining the transparent or translucent state of the emulsion.

[0052] In addition, the cellulose molecules in cotton fabrics contain a large number of hydroxyl groups, which are easily weakly ionized in aqueous solutions, giving the fiber surface a negative charge. Meanwhile, the emulsion particles have a positive potential of +40 to +50 mV, which can be pre-adsorbed onto the negatively charged cotton fabric surface through Coulomb forces, allowing the fluorine-free waterproofing agent particles to adhere more tightly to the fiber surface.

[0053] In a preferred embodiment, the raw materials for preparing the organosilicon-modified fluorine-free waterproofing finishing agent of this application, by mass fraction, include: 8%~15% modified acrylate, 1%~10% end-capped isocyanate, 10%~20% long-chain acrylate, 2%~8% short-chain acrylate, 0.5%~1% initiator, 1%~10% emulsifier, 6%~15% organic solvent, and the balance being water.

[0054] In the silicone-modified fluorine-free waterproofing agent of this application, the content of long-chain acrylate is relatively small and has little impact on the hydrophobic properties of the product. However, if the content of long-chain acrylate is further increased, the long-chain acrylate will become entangled and lose its waterproofing effect.

[0055] This application also provides a method for preparing an organosilicon-modified fluorine-free waterproofing finishing agent, comprising the following preparation steps: S1: Amino silicone oil is mixed with glycidyl methacrylate and heated to obtain modified acrylate; capping agent is mixed with active isocyanate monomer and heated to react to obtain capped isocyanate; S2: Modified acrylate, capped isocyanate, acrylate monomer, emulsifier, organic solvent and water are mixed and then subjected to high-speed shearing and homogenization to obtain a pre-emulsion; S3: Heat the pre-emulsion and add the initiator, continue the reaction at the temperature for a period of time to obtain the organosilicon-modified fluorine-free waterproof finishing agent of this application.

[0056] In some embodiments, amino silicone oil is mixed with glycidyl methacrylate, and the mixture is heated at 100-120°C for 30-60 min to obtain modified acrylate.

[0057] In some embodiments, the capping agent and the active isocyanate monomer react in a molar ratio of (1~2):1, and more preferably, the capping agent and the active isocyanate monomer react in a molar ratio of 1.02:1.

[0058] Preferably, the capping agent and the active isocyanate are reacted at 60-80 °C for 1-2 hours to obtain the capped isocyanate.

[0059] In some embodiments, an initiator is added when the pre-emulsion is heated to 55-60 °C, and then the reaction is continued for 3-6 hours to obtain the organosilicon-modified fluorine-free waterproof finishing agent of this application.

[0060] The organosilicon-modified fluorine-free waterproofing agent of this application does not contain fluorine, is environmentally friendly, has a simple and efficient preparation method, and is suitable for storage and transportation.

[0061] Example 1 The organosilicon-modified fluorine-free waterproofing agent of Example 1 was prepared according to the following steps: S1: 100.0 g glycidyl methacrylate and 15.0 g amino-polydimethylsiloxane were mixed evenly at room temperature and sonicated for 30 min. The homogeneous mixture was heated at 100 °C for 45 min in a three-necked flask and cooled to obtain the modified acrylate. 156 g isocyanate methacrylate and 98.1 g 3,5-dimethylpyrazole were reacted at 60~70 °C for 1 hour to obtain the first end-capped isocyanate. S2: 40 g of modified acrylate, 5 g of first-terminated isocyanate, 75 g of dodecyl acrylate, 8 g of n-butyl acrylate, 4 g of emulsifier dodecyltrimethylammonium chloride, 20 g of dipropylene glycol, and 238 g of water were mixed at 55-60 °C for 20 min, and then subjected to high-speed shearing and high-pressure homogenization to obtain a pre-emulsion. S3: Add the pre-emulsion to a four-necked flask equipped with a stirrer, thermometer and condenser. When the temperature rises to 55°C, add 2 g of azobisisobutylamidine hydrochloride. Then keep warm at 55~60°C for 5 h to obtain the organosilicon-modified fluorine-free waterproof finishing agent of this application.

[0062] Example 2 156 g of isocyanate methacrylate and 98.1 g of 3,5-dimethylpyrazole were reacted at 60-70 °C for 1 hour to obtain the first-terminated isocyanate; 115 g of ethoxycarbonyl isocyanate and 98.1 g of 3,5-dimethylpyrazole were reacted at 60-65 °C for 1 hour to obtain the second-terminated isocyanate. In step S2, the 5 g of capped isocyanate was adjusted to 5 g of first capped isocyanate and 3 g of second capped isocyanate, and the amount of water added was adjusted to 235 g. Other preparation conditions remained the same as those in Example 1.

[0063] Example 3 142 g of ethyl isocyanate acrylate and 106 g of NaHSO3 were reacted at 65-75℃ for 1 hour. 20-30 g of butanone could be added to aid dissolution to obtain the third-terminated isocyanate. In step S2, the 5 g of capped isocyanate was adjusted to 5 g of first capped isocyanate and 3 g of third capped isocyanate, and the amount of water added was adjusted to 235 g. Other preparation conditions remained the same as those in Example 1.

[0064] Example 4 The amount of modified acrylate added in step S2 was adjusted to 45 g, the amount of dodecyl acrylate added was adjusted to 65 g, and the amount of n-butyl acrylate added was adjusted to 13 g. Other preparation conditions remained the same as those in Example 1.

[0065] Example 5 The amount of first-terminated isocyanate added in step S2 was adjusted to 10 g, and the amount of water added was adjusted to 233 g. Other preparation steps remained the same as those in Example 3.

[0066] Comparative Example 1 In step S1, no modified acrylate is prepared, and in step S2, the same mass of glycidyl methacrylate is used to replace the modified acrylate. The other preparation steps are consistent with the preparation steps in Example 1 to obtain the fluorine-free waterproof finishing agent of Comparative Example 1.

[0067] Comparative Example 2 In step S2, no end-capped isocyanate was added, and the other preparation steps were consistent with those in Example 1, thus obtaining the fluorine-free waterproof finishing agent of Comparative Example 2.

[0068] Comparative Example 3 In step S2, no short-chain acrylates were added, and the amount of dodecyl acrylate added was adjusted to 83 g. The other preparation steps were consistent with the preparation steps in Example 1, and the fluorine-free waterproof finishing agent of Comparative Example 3 was obtained.

[0069] Comparative Example 4 In step S2, no acrylate monomers are added, and the other preparation steps are consistent with those in Example 1, thus obtaining the fluorine-free waterproof finishing agent of Comparative Example 4.

[0070] Cotton fabric treatment: Take 25 g / L of the finishing agent prepared in Examples 1 to 5 and Comparative Examples 1 to 4 above, dip and rub, and set at 160 ℃ for 2 min to treat the cotton fabric. Cool the treated cotton fabric to room temperature and perform performance tests together with the original fabric.

[0071] Performance testing 1. Waterproofing Test: The waterproofing performance of raw and treated cotton fabrics was examined according to the national standard GB / T4745-2012. A 18×18 cm sample was cut, clamped, and mounted on a fixed base at a 45° angle to the horizontal. 250 mL (20±2 ℃) of distilled or deionized water was rapidly and steadily poured into a funnel. The sample was then sprayed evenly and continuously towards the center of the sample through a nozzle positioned at a distance from the sample center over 25–30 seconds. After spraying, the clamp was quickly removed, and the sample was placed face down and horizontal. The sample was gently tapped twice, and the degree of wetting was observed. The grade was then assessed using both text and images. The average of three measurements was taken, and the grading criteria are shown in Table 1 below.

[0072] Table 1 Waterproof Performance Rating Standards

[0073] 2. Washability test: The original cotton fabric, the cotton fabrics treated with the finishing agents in each example and each comparative example were subjected to 10 standard washes, and then the waterproof effect was tested.

[0074] 3. Hand feel evaluation test: The overall hand feel is evaluated by touch. The evaluation includes the original cotton fabric, the cotton fabric treated with finishing agents in each example and comparative example, and the cotton fabric after 10 standard washes. The hand feel evaluation is divided into poor and soft.

[0075] The performance test results of the above-mentioned cotton fabric, each embodiment, and each comparative example are recorded in Table 2 below.

[0076] Table 2 Performance test results of cotton fabric, various examples and comparative examples

[0077] Analysis of the performance test results in Table 2 shows that, compared with the original cotton fabric, the organosilicon-modified fluorine-free waterproofing agent prepared in this application has better waterproofing effect, improves fabric softness, and can maintain waterproof performance and comfort even after 10 washes, making it suitable for application in the textile field.

[0078] Compared with Comparative Example 1 (lacking modified acrylate), Comparative Example 2 (lacking capped isocyanate), Comparative Example 3 (without added short-chain acrylate), and Comparative Example 4 (without added acrylate monomer), the key components of the silicone-modified fluorine-free waterproof finishing agent of this application have an indispensable impact on the performance of the finishing agent. The multi-formulation composite achieves multiple goals such as fluorine-free environmental protection, high waterproofness, soft hand feel, and high water resistance, solving the technical pain points in the industry.

[0079] In summary, the organosilicon-modified fluorine-free waterproof finishing agent of this application uses modified acrylate, capped isocyanate, acrylate monomer, emulsifier, initiator, organic solvent, and water as raw materials. The modified acrylate is prepared by reacting amino silicone oil with glycidyl methacrylate, and the capped isocyanate is generated by reacting a capping agent with an active isocyanate monomer. The acrylate monomer is a combination of long-chain and short-chain monomers. The preparation process involves first separately preparing the modified acrylate and capped isocyanate, then mixing them with other raw materials to form a pre-emulsion, and finally adding an initiator to react and obtain the product. This finishing agent is fluorine-free and environmentally friendly, imparts a soft hand feel to cotton fabrics, and exhibits excellent waterproof performance and wash fastness. The preparation method is simple and efficient, and it is convenient for storage and transportation.

[0080] The basic principles, main features, and advantages of this application have been described above. Those skilled in the art should understand that this application is not limited to the above embodiments. The embodiments and descriptions in the specification are merely the principles of this application. Various changes and modifications can be made to this application without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claims. The scope of protection claimed by this application is defined by the appended claims and their equivalents.

Claims

1. A silicone-modified fluorine-free waterproofing finishing agent, characterized in that, The raw materials for preparation include modified acrylate, capped isocyanate, acrylate monomer, emulsifier, initiator, organic solvent and water, wherein the raw materials for preparation of the modified acrylate include amino silicone oil and glycidyl methacrylate.

2. The organosilicon-modified fluorine-free waterproofing agent as described in claim 1, characterized in that, The modified acrylate is prepared by mixing the amino silicone oil and glycidyl methacrylate and heating to 100~120 °C.

3. The organosilicon-modified fluorine-free waterproofing agent as described in claim 1, characterized in that, The method for preparing the terminated isocyanate is as follows: the terminating agent is mixed with an active isocyanate monomer and heated to react for a period of time to obtain the terminated isocyanate.

4. The organosilicon-modified fluorine-free waterproofing agent as described in claim 3, characterized in that, The capping agent is any one or a combination of multiple of acetone oxime, butanone oxime, cyclohexanone oxime, ξ-caprolactam, 3,5-dimethylpyrazole, KHSO3, NaHSO3, 1,2,4-triazole, and nonylphenol.

5. The organosilicon-modified fluorine-free waterproofing agent as described in claim 3, characterized in that, The active isocyanate monomer is Wherein R is a C2-C22 linear or branched alkyl group; or, the active isocyanate monomer is R1 is a C2-C18 branched chain or branched alkyl group; or, the active isocyanate monomer is... R2 is a C2-C22 linear or branched alkyl group; or the active isocyanate monomer is R3 is a C2-C22 linear or branched alkyl group.

6. The organosilicon-modified fluorine-free waterproofing agent as described in claim 1, characterized in that, The acrylate monomers include long-chain acrylates and short-chain acrylates, wherein the long-chain acrylates contain at least 12 alkyl carbons and the short-chain acrylates contain at most 8 alkyl carbons.

7. The organosilicon-modified fluorine-free waterproofing agent as described in claim 6, characterized in that, The long-chain acrylate is one or a mixture of more of the following: lauryl acrylate, hexadecyl acrylate, hexadecyl methacrylate, octadecyl acrylate, octadecyl methacrylate, docosyl acrylate, docosyl methacrylate, and 2-methyl-2-octadecyl acrylate; the short-chain acrylate is one or a mixture of more of the following: methyl acrylate, methyl methacrylate, ethyl acrylate, n-butyl acrylate, and isooctyl acrylate.

8. The organosilicon-modified fluorine-free waterproofing agent as described in claim 1, characterized in that, The emulsifier is one or more of the following: cashew phenol polyoxyethylene polyoxypropylene ether, linear fatty alcohol polyoxyethylene ether, branched fatty alcohol polyoxyethylene ether, branched fatty alcohol polyoxyethylene polyoxypropylene ether, fatty amine polyoxyethylene ester, and fatty acid polyoxyethylene ester; the initiator is one or more of the following: ammonium persulfate, benzoyl peroxide, di-tert-butyl peroxide, dicumyl peroxide, tert-butyl hydroperoxide, sodium persulfate, potassium persulfate, azobisisobutyronitrile, azobisisobutyramidine hydrochloride, and azobisisoheptanenitrile.

9. A method for preparing an organosilicon-modified fluorine-free waterproofing finishing agent, characterized in that, The preparation steps include the following: S1: Amino silicone oil is mixed with glycidyl methacrylate and heated to obtain modified acrylate; capping agent is mixed with active isocyanate monomer and heated to react to obtain capped isocyanate; S2: The modified acrylate, the terminated isocyanate, the acrylic monomer, the emulsifier, the organic solvent and water are mixed and subjected to high-speed shearing and homogenization to obtain a pre-emulsion; S3: Heat the pre-emulsion and add an initiator, and keep it warm for a period of time to obtain the organosilicon-modified fluorine-free waterproof finishing agent.

10. The preparation method according to claim 9, characterized in that, In step S1, the amino silicone oil and the glycidyl methacrylate are heated and reacted at 100-120 °C for 30-60 min, and the capping agent and the active isocyanate monomer are reacted at 60-80 °C for 1-2 hours. In step S3, when the pre-emulsion is heated to 55-60 °C, an initiator is added, and then the reaction is continued for 3-6 hours to obtain the organosilicon-modified fluorine-free waterproof finishing agent.

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