High-color-fastness washable polyethylene fabric and preparation process thereof

Abstract

The invention discloses a high-color-fastness washable polyethylene fabric and a preparation process thereof in the field of functional polymer materials. The high-color-fastness washable polyethylene fabric is prepared from the following raw materials: polyethylene resin, maleic anhydride-acrylic acid copolymer grafted polyethylene, dopamine-silane composite modified polyethylene, magnesium stearate and an antioxidant. Wherein the maleic anhydride-acrylic acid copolymer grafted polyethylene is prepared by copolymerizing maleic anhydride and acrylic acid and then blending and granulating with polyethylene, and carboxyl and acrylate groups are introduced to enhance the binding force with dye; the dopamine-silane composite modified polyethylene is prepared through polyethylene surface hydroxylation, dopamine self-polymerization modification and silane grafting reaction, and the acting force and hydrophobicity between fibers are doubly improved through a catechol group and an epoxy group. According to the prepared fabric, the color fastness and the washing resistance are remarkably improved, meanwhile, the original characteristics of light weight and chemical corrosion resistance of polyethylene are kept, and the application scene is expanded.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of functional polymer materials, and in particular to a polyethylene fabric with high color fastness and washing resistance and a preparation process thereof. BACKGROUND

[0002] As an important member in the field of polymer materials, polyethylene (PE) occupies a unique position in the textile field due to its light weight, chemical corrosion resistance, and easy processing. From casual wear to outdoor functional clothing, from home bedding to industrial protective fabrics, polyethylene fabric is widely used due to its low cost and high durability. However, with the upgrading of consumers' quality requirements for textiles, the limitations of traditional polyethylene fabric are increasingly prominent. The molecular chain of traditional polyethylene fabric is dominated by carbon-hydrogen structure, and the content of polar groups is extremely low, resulting in insufficient surface energy, which makes it difficult for dye molecules to effectively combine through hydrogen bonding, dipole interaction, etc., ultimately resulting in low rubbing fastness and washing fastness. At the same time, the fibers are only combined by van der Waals force, and the dye migration is easily caused by swelling due to moisture absorption during washing, resulting in color loss or even fabric discoloration. These problems not only affect the appearance durability of the product, but also limit the expansion of polyethylene fabric to high-end clothing, home textiles, and other fields with strict color fastness requirements.

[0003] In view of the performance shortcomings of traditional polyethylene fabric, the industry has carried out multiple rounds of technical exploration. Early research focused on surface modification, such as directly covering the fiber surface by coating adhesives or dye auxiliaries, which can improve color fastness in the short term, but the coating has weak adhesion to the fiber, and it is easy to fall off after repeated washing, and the durability is insufficient. Subsequent blending modification technology attempts to blend polar polymers such as polyacrylonitrile and nylon with polyethylene, trying to enhance the dye binding ability by introducing polar components, but the compatibility between different polymers is poor, and the blending system is prone to phase separation, which not only leads to a decrease in mechanical properties (such as strength and toughness) of the material, but also may cause local uneven dyeing due to uneven distribution of polar components. In recent years, single grafting modification technology has gradually emerged, such as introducing carboxyl groups on the surface of polyethylene by maleic anhydride grafting, which can partially improve the binding force with dyes, but the function is single, and only color fastness can be improved, and the effect of washing resistance is limited, and molecular chain rupture is easily caused during grafting, resulting in poor processing fluidity of the material. These technologies have not been able to break through the bottleneck of polyethylene fabric color fastness and washing resistance due to one-sided effect, complex process, or high cost.

[0004] Under the background of consumption upgrading and industry technology iteration, it has become an inevitable trend to develop polyethylene fabrics with high color fastness and washing resistance. Market research shows that the color fastness requirements of high-end clothing, baby products, hotel bed linen and other fields have been upgraded from the traditional 3-4 level to 4.5 level or above, and the color should remain stable after multiple washes. The limitations of traditional modification technology force the industry to seek new solutions, which not only enhance the dye combination through polar groups to improve color fastness, but also inhibit dye migration through cross-linked structure to enhance washing resistance, while maintaining the original advantages of polyethylene such as light weight and chemical corrosion resistance. Based on this, the invention proposes a double modification synergistic technology: using maleic anhydride-acrylic acid copolymer grafted polyethylene to introduce carboxyl and acrylic ester group bipolar groups to strengthen hydrogen bonding and dipole interaction with dyes; combining the catechol group and epoxy group of dopamine-silane composite modified polyethylene to double inhibit dye migration. This scheme breaks through the limitations of single modification and provides a new technical path for the development of high-performance polyethylene fabrics. SUMMARY

[0005] The purpose of the present application is to provide a high color fastness and washing resistant polyethylene fabric and its preparation process, which solves the problem of poor color fastness (rubbing and washing) and insufficient washing resistance of traditional polyethylene fabrics due to weak molecular chain polarity and low surface energy.

[0006] The present application realizes the above-mentioned purpose by the following technical solutions: A high color fastness and washing resistant polyethylene fabric, by mass percentage, its raw materials include: Polyethylene resin: 78-85%; Maleic anhydride-acrylic acid copolymer grafted polyethylene: 7-10%; Dopamine-silane composite modified polyethylene: 5-8%; Magnesium stearate: 1.8-2.5%; Antioxidant: 1-1.5%; The preparation method of the maleic anhydride-acrylic acid copolymer grafted polyethylene includes: A1, adding maleic anhydride and acrylic acid into toluene solvent, purging nitrogen to remove oxygen, then adding benzoyl peroxide, heating to 75-85℃, after reaction, reducing pressure distillation to obtain maleic anhydride-acrylic acid copolymer; A2, then mix the maleic anhydride-acrylic acid copolymer with high density polyethylene, add into a twin-screw extruder, set the extrusion temperature to 190-210℃, blend extrusion and granulation.

[0007] In the preparation of the maleic anhydride-acrylic acid copolymer grafted polyethylene, first, a bipolar functional carrier is constructed by free radical reaction: maleic anhydride and acrylic acid are polymerized under the action of an initiator to form a random copolymer containing two polar groups, one of which (such as carboxyl) is highly polar and can form a stable combination with a dye molecule; the other group (such as an acrylate group) is slightly weaker in polarity and can adjust the intermolecular force to avoid the material being too hard. When the copolymer is granulated by melt blending with high-density polyethylene (HDPE), the polar groups of the copolymer will migrate to the surface of the polyethylene, forming a structure similar to a "polar patch" to provide reaction sites for subsequent modification.

[0008] According to a preferred embodiment of the present application, the polyethylene resin is purchased from SINOPEC Shanghai Petrochemical Co., Ltd., and the model number is HDPE 5000S.

[0009] According to a preferred embodiment of the present application, the maleic anhydride is purchased from Wanhua Chemical Group Co., Ltd., and the model number is Maleic Anhydride (industrial grade).

[0010] According to a preferred embodiment of the present application, the acrylic acid is purchased from Satellite Chemical Co., Ltd., and the model number is Acrylic Acid (industrial grade).

[0011] According to a preferred embodiment of the present application, the toluene is purchased from Zhenhai Refining and Chemical Co., Ltd., and the model number is Toluene (industrial grade).

[0012] According to a preferred embodiment of the present application, the nitrogen gas is purchased from Hangzhou Hangyang Co., Ltd., and the model number is Industrial Nitrogen Gas (purity ≥ 99.9%).

[0013] According to a preferred embodiment of the present application, the benzoyl peroxide is purchased from Jiangsu Qiangsheng Functional Chemical Co., Ltd., and the model number is BPO-98 (industrial grade).

[0014] According to a preferred embodiment of the present application, the high-density polyethylene is purchased from Yanshan Petrochemical Co., Ltd., and the model number is 5200B.

[0015] According to a preferred embodiment of the present application, the twin-screw extruder is purchased from Nanjing Koyea Chemical Engineering Equipment Co., Ltd., and the model number is SK-80 (parallel twin-screw extruder).

[0016] According to a preferred embodiment of the present application, the magnesium stearate is purchased from Dandong Chemical Factory No. 3, and the model number is Magnesium Stearate (industrial grade).

[0017] According to the preferred embodiment of the present application, the antioxidant is purchased from the company of Ciba Specialty Chemicals Inc., and the model number is 1010 (tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid]pentaerythritol ester).

[0018] According to the preferred embodiment of the present application, in step A1, the molar ratio of maleic anhydride to acrylic acid is 1: (1.5-2); the content of benzoyl peroxide is 0.8-1.2% of the total mass of monomers; the reaction time is 6-8 h at a temperature of 75-85℃.

[0019] According to the preferred embodiment of the present application, in step A2, the mass ratio of maleic anhydride-acrylic acid copolymer to high-density polyethylene is 1: (4-5); the temperature of the compression section of the twin-screw extruder is 199-201℃, the temperature of the metering section is 204-206℃, the screw rotation speed is 400-500 rpm, and the residence time of the blending extrusion granulation is 3-4 min.

[0020] According to the preferred embodiment of the present application, the preparation method of the dopamine-silane composite modified polyethylene comprises: B1, polyethylene resin particles are soaked in an ethanol-water mixed solution, a silane coupling agent is added, and after ultrasonic dispersion, the particles are taken out and vacuum dried to obtain hydroxylated polyethylene. Then the hydroxylated polyethylene and dopamine hydrochloride are added into a Tris-HCl buffer solution, and a magnetic stirring reaction is carried out at 24-26℃. After the reaction is completed, centrifugal washing is carried out, and vacuum drying is carried out at 40-42℃ to obtain polydopamine modified polyethylene; B2, the polydopamine modified polyethylene and γ-glycidyl ether oxypropyl trimethoxysilane are added into anhydrous ethanol, ultrasonic dispersion is carried out at 60-62℃, and then the temperature is raised to 80-82℃ for reflux reaction. After the reaction is completed, the product is removed by vacuum distillation, and vacuum drying is carried out.

[0021] In the present application, the preparation of dopamine-silane composite modified polyethylene is divided into two steps of surface functionalization and cross-linking reinforcement: first, after ultrasonic dispersion treatment, polyethylene particles adsorb water on the surface to form a small amount of hydroxyl groups; after the addition of a silane coupling agent, the silane coupling agent reacts with the hydroxyl groups to form siloxane bonds, so that the polyethylene surface has more reactive sites. Subsequently, polyethylene reacts with dopamine in an alkaline environment. The special structure (containing multiple phenolic hydroxyl groups) in the dopamine molecule can self-polymerize on the surface of polyethylene to form a thin and uniform coating. The phenolic hydroxyl groups can form hydrogen bonds with the hydroxyl groups on the surface of polyethylene, and can also combine with certain groups (such as hydroxyl groups or sulfonic acid groups in the dye) in the dye molecule, thereby enhancing the adhesion of the dye. Finally, the coating reacts with a silane compound containing an epoxy group, the epoxy group further cross-links with the phenolic hydroxyl group to form a network structure throughout the coating, and at the same time, physical cross-linking points are formed between the fibers to inhibit the migration of the dye caused by the swelling of the fibers during washing; the other end of the silane will form a hydrophobic segment to build a "waterproof barrier" on the surface of the fiber, thereby reducing the dissolution of the dye caused by water penetration.

[0022] According to the preferred embodiment of the present application, the silane coupling agent is purchased from Nanjing Shuguang Silane Chemical Co., Ltd., and the model number is KH570 (γ-methacryloxypropyltrimethoxysilane).

[0023] According to the preferred embodiment of the present application, the dopamine hydrochloride is purchased from Shanghai Aladdin Bio-Chem Technology Co., Ltd., and the model number is D101001 (dopamine hydrochloride, analytical pure).

[0024] According to the preferred embodiment of the present application, the Tris-HCl buffer solution is purchased from Beijing Solaybao Technology Co., Ltd., and the model number is T1076 (Tris-HCl buffer solution, pH 8.5).

[0025] According to the preferred embodiment of the present application, the γ-glycidyl ether oxypropyl trimethoxysilane is purchased from Hubei Xingfa Chemical Industry Group Co., Ltd., and the model number is XFG-570 (γ-glycidyl ether oxypropyl trimethoxysilane).

[0026] According to the preferred embodiment of the present application, the anhydrous ethanol is purchased from Sinopec Great Wall Energy Chemical (Ningxia) Co., Ltd., and the model number is E-001 (anhydrous ethanol, industrial grade).

[0027] According to the preferred embodiment of the present application, in step B1, the ultrasonic dispersion time is 30-40 min; the vacuum drying temperature is 60-62℃, and the vacuum drying time is 4-6h; the dopamine hydrochloride accounts for 3-5% of the mass of the polyethylene resin; and the magnetic stirring reaction time is 24-26h.

[0028] According to the preferred embodiment of the present application, in step B2, the γ-glycidyl ether oxypropyl trimethoxysilane accounts for 5-7% of the mass of the polydopamine modified polyethylene; the ultrasonic dispersion time is 20-22 min; the heating to 80-82℃ reflux reaction time is 4-6h; the vacuum drying temperature is 60-62℃, and the vacuum drying time is 12-14h.

[0029] The present application also provides a preparation method of the high color fastness and washing resistant polyethylene fabric, and the steps include: S1, polyethylene resin, maleic anhydride-acrylic acid copolymer grafted polyethylene, dopamine-silane composite modified polyethylene, magnesium stearate and antioxidant are added into a high-speed mixer and mixed to obtain a modified blend; S2, melt spinning the modified blend in a twin-screw extruder, setting the extrusion temperature to 175-195 DEG C, obtaining the primary fiber after cooling; the primary fiber is made into a polyester filament fabric gray cloth through two stretching and heat setting processes, wherein the first stretching temperature is 90-100 DEG C, the ratio is 3 times; the second stretching temperature is 110-120 DEG C, the ratio is 2 times; the heat setting temperature is 160-170 DEG C; S3, the polyester filament fabric gray cloth is immersed in an active dye dyeing solution, pre-dyed at 60-62 DEG C, dyed by increasing the temperature to 80-82 DEG C, fixed by a fixing agent at 70-72 DEG C after washing, and finally dried at 100-102 DEG C.

[0030] In the fabric preparation process of the present application, each component is uniformly dispersed through melt blending: polyethylene provides basic performance as the main body, the bipolar group of maleic anhydride-acrylic acid copolymer and the coating and network structure of dopamine-silane composite modified layer jointly constitute a 'polar combination-crosslinking barrier' dual functional system. The high-speed mixing process uniformly disperses the modifier through mechanical shearing, avoiding local aggregation of the polar group; during the twin-screw extrusion spinning, the melting temperature and the extrusion speed control the forming structure of the fiber, and the appropriate temperature ensures that the modifier is fully integrated, and the reasonable speed ensures the uniformity of the fiber fineness. The two stretching processes arrange the molecular chains in order through stress, and at the same time promote the coating and the network structure to further crosslink, thereby enhancing the fiber strength; the heat setting process fixes the fiber morphology through high temperature, thereby reducing the shrinkage deformation in subsequent use.

[0031] According to the preferred embodiment of the present application, the high-speed mixer is purchased from Jiangsu Yongli Machinery Manufacturing Co., Ltd., and the model is YH-1000 (high-speed mixer, volume 1000L).

[0032] According to the preferred embodiment of the present application, the active dye dyeing solution is purchased from Zhejiang Longsheng Group Co., Ltd., and the model is Lonsen Red 195 Liquid Dye (active red 195 liquid dye, concentration 200g / L).

[0033] According to the preferred embodiment of the present application, the fixing agent is purchased from Guangdong Demax Fine Chemical Group Co., Ltd., and the model is DM-2513 (cationic fixing agent, solid content 30%).

[0034] According to the preferred embodiment of the present application, in step S1, the mixing speed is 1000-1200 rpm, and the mixing time is 15-20 min.

[0035] According to the preferred embodiment of the present application, in step S2, the temperature of the melting section in the twin-screw extruder is 184-186 DEG C, the temperature of the metering section is 189-191 DEG C, the spinning speed is 2000-2500 m / min, the cooling air speed is 0.3-0.5 m / s; the heat setting time is 10-12 min.

[0036] According to the preferred embodiment of the present application, in step S3, the concentration of the dye is 2-3 g / L, the pre-dyeing time is 10-12 min, the dyeing time at 80-82 DEG C is 40-42 min; the concentration of the fixing agent is 3-4 g / L; the fixing time at 70-72 DEG C is 30-40 min; the drying time at 100-102 DEG C is 8-10 min.

[0037] In the dyeing stage of the present application, the polar groups (such as hydroxyl or sulfonic acid group) of the reactive dye can form strong hydrogen bonds with the carboxyl groups (from the copolymer) on the surface of the polyethylene, combine with the phenolic hydroxyl groups of the dopamine coating (such as esterification reaction), and also adhere to the hydrophobic segments of the silane network structure through van der Waals force, realizing the "hydrogen bond-combination-hydrophobic" multiple fixation. The cationic groups in the fixing agent can electrostatically combine with the anionic groups of the dye, further enhancing the adhesion of the dye. During washing, the physical cross-linking of the silane network structure hinders the migration of the dye with water flow, and the hydrophobic property of the dopamine coating reduces water penetration, ultimately significantly improving the color fastness and washing resistance of the fabric.

[0038] The present application has the following advantages: The present application significantly improves the color fastness performance of polyethylene fabric through double modification synergistic technology. Traditional polyethylene has weak molecular chain polarity, which results in insufficient binding force with dye molecules, leading to easy color fading during rubbing and washing. In the present application, the maleic anhydride-acrylic acid copolymer grafted polyethylene introduces carboxyl and acrylic ester groups through copolymerization, where the carboxyl group can form strong hydrogen bonds or dipole interactions with dye molecules, and the acrylic ester group can enhance the interfacial adhesion between dye and fiber through polar adsorption; the polydopamine layer in the dopamine-silane modified polyethylene contains a large number of catechol groups, which can form coordinate bond with dye molecules, further improving the stability of dye on the fiber surface. The synergistic effect of the two modifiers changes the combination of dye and fiber from single physical adsorption to dual action of chemical bonding and strong polar adsorption, significantly reducing the risk of dye detachment during washing and rubbing, and ultimately achieving overall improvement of fabric color fastness.

[0039] The wash-resistant performance of the present application is double-protected by cross-linking network construction and hydrophobic structure strengthening. The dopamine-silane composite modified polyethylene contains epoxy groups in the gamma-glycidyl ether oxypropyl trimethoxysilane, which can undergo cross-linking reaction with the hydroxyl groups on the fiber surface to form a three-dimensional network structure, effectively inhibiting the swelling and dye migration between fibers during washing; at the same time, the siloxane segments formed after hydrolysis have natural hydrophobicity, which can form a hydrophobic barrier on the fiber surface, reducing the dissolution effect of water penetration on the dye. In addition, the high crystallinity and low polarity characteristics of the polyethylene resin further reduce the diffusion rate of the dye inside the fiber. This dual protection mechanism of "cross-linking fixation + hydrophobic barrier" makes the dye less likely to separate from the fiber during washing, and the wash-resistant performance is significantly improved compared to traditional polyethylene fabrics.

[0040] The present application retains the original advantages of polyethylene resin while improving color fastness and wash-resistant performance, ensuring the overall practicality of the fabric. The high molecular chain structure of polyethylene resin gives the fabric light weight and softness, and its low surface energy characteristics maintain good stain resistance; the introduction of maleic anhydride-acrylic acid copolymer and dopamine-silane composite modifier does not damage the processing flowability of polyethylene, and the fabric can still be formed by conventional spinning and stretching process, ensuring production efficiency and cost controllability. In addition, the synergistic effect of the two modifiers does not introduce additional brittle or toxic substances, and the fabric still maintains good chemical stability and biocompatibility. These characteristics make it have wide application prospects in high-end clothing (such as outdoor jackets, baby clothing), home textiles (such as high-end beddings, curtains) and other fields, effectively solving the market application limitations of traditional polyethylene fabrics due to insufficient color fastness and wash-resistant performance. DETAILED DESCRIPTION

[0041] The following detailed description is only used to further illustrate the present application and cannot be understood as limiting the scope of protection of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application based on the above application content.

[0042] I. Example

[0043] Example 1

[0044] Weigh the raw materials by mass: polyethylene resin 800g, maleic anhydride-acrylic acid copolymer grafted polyethylene 80g, dopamine-silane composite modified polyethylene 60g, magnesium stearate 20g, antioxidant 15g.

[0045] Preparation of maleic anhydride-acrylic acid copolymer grafted polyethylene: Maleic anhydride and acrylic acid were mixed in a molar ratio of 1:1.8 and added to a 1000 mL three-necked flask equipped with a mechanical stirring device, a thermometer, and a nitrogen inlet tube. Then, 500 mL of toluene solvent was added. Nitrogen was introduced to replace the air in the flask for 30 minutes to ensure that the reaction system was in an oxygen-free environment. Then, benzoyl peroxide (1% of the total mass of maleic anhydride and acrylic acid monomers) was added to the flask, and the temperature was slowly raised to 80°C and kept constant. The stirring reaction was continued for 7 hours. After the reaction was completed, the reaction solution was transferred to a rotary evaporator, and the toluene solvent was removed by distillation under reduced pressure (vacuum degree -0.09 MPa, temperature 60°C) to obtain maleic anhydride-acrylic acid copolymer solid. Then, the copolymer was mixed with high-density polyethylene (HDPE, melt index 8 g / 10 min) at a mass ratio of 1:4.5 and added to a twin-screw extruder. The temperature of each zone of the twin-screw extruder was set as follows: feeding section 170°C, compression section 200°C, metering section 205°C, and die head temperature 195°C. The screw rotation speed was 450 rpm, and the residence time of the material in the extruder was about 3.5 minutes. After extrusion, cooling, and granulation, maleic anhydride-acrylic acid copolymer grafted polyethylene particles were obtained.

[0046] Preparation of dopamine-silane composite modified polyethylene: Polyethylene resin particles were added to an ethanol-water mixed solution (volume ratio 3:1, total volume 1000 mL) and ultrasonically dispersed for 35 minutes at a power of 300 W and a frequency of 40 kHz to uniformly adsorb water on the surface of the polyethylene particles to form hydroxyl groups. After ultrasonic treatment, the polyethylene particles were removed and transferred to a vacuum drying oven, and dried at 60°C for 5 hours under vacuum (vacuum degree -0.08 MPa) to obtain surface-hydroxylated polyethylene. The surface-hydroxylated polyethylene and dopamine hydrochloride (4% of the mass of the polyethylene resin) were added to a Tris-HCl buffer solution (pH 8.5, total volume 500 mL) and reacted at 25°C on a constant-temperature magnetic stirrer at a rotation speed of 300 rpm for 25 hours. After the reaction was completed, the mixture was transferred to a centrifuge tube and centrifuged at a rotation speed of 8000 rpm for 10 minutes. The precipitate was collected and washed with deionized water until it was neutral. Finally, the precipitate was placed in a vacuum drying oven and dried at 41°C for 5 hours under vacuum (vacuum degree -0.08 MPa) to obtain polydopamine modified polyethylene. The polydopamine modified polyethylene and γ-glycidoxypropyltrimethoxysilane (6% of the mass of the polydopamine modified polyethylene) were added to anhydrous ethanol (volume 500 mL), ultrasonically dispersed at 61°C for 21 minutes (ultrasonic power 200 W), and then heated to 81°C for reflux reaction for 5 hours (the reflux device was kept in a slightly boiling state). After the reaction was completed, the anhydrous ethanol was removed by distillation under reduced pressure (vacuum degree -0.09 MPa, temperature 50°C), and the remaining solid was placed in a vacuum drying oven and dried at 61°C for 13 hours under vacuum (vacuum degree -0.08 MPa) to obtain dopamine-silane composite modified polyethylene particles.

[0047] Fabric preparation: Polyethylene resin, maleic anhydride-acrylic acid copolymer grafted polyethylene, dopamine-silane complex modified polyethylene, magnesium stearate, antioxidant were added into a high-speed mixer and mixed at 1100 rpm for 18 minutes (mixer capacity 2 L) to obtain a modified blend. The modified blend was added into a twin-screw extruder for melt spinning, and the temperature of each zone was set as follows: feeding section 165 °C, compression section 185 °C, metering section 190 °C, die temperature 180 °C; screw rotation speed 250 rpm, melt pump pressure 8 MPa. The polymer melt after melting was extruded into filaments through a spinneret, and the cooling air speed was 0.4 m / s (cooling medium was air at 25 °C) to obtain nascent fibers with a diameter of about 22 pm. The nascent fibers were stretched in two stages: the first stretching temperature was 95 °C, and the stretching ratio was 3 times; the second stretching temperature was 115 °C, and the stretching ratio was 2 times. The stretched fibers were heat set in a heat setting machine at 165 °C for 11 minutes to obtain polyester filament fabric greige (about 130 g / m2in weight). The greige was immersed in an active dye dyeing solution (active red 195, concentration 2.5 g / L, bath ratio 1:15), pre-dyed at 61 °C for 11 minutes, then heated to 81 °C at a rate of 1 °C / min, and kept for 41 minutes. After dyeing, the greige was washed with deionized water for 3 times (5 minutes each time), and then fixed with a fixing agent (concentration 3.5 g / L) at 71 °C for 35 minutes. Finally, the greige was placed in an oven and dried at 101 °C for 9 minutes to obtain a high color fastness and wash-resistant polyethylene fabric.

[0048] Example 2

[0049] The preparation method is the same as in Example 1, except that the raw materials are weighed in percentage by mass as follows: polyethylene resin 790 g, maleic anhydride-acrylic acid copolymer grafted polyethylene 90 g, dopamine-silane composite modified polyethylene 70 g, magnesium stearate 22 g, antioxidant 13 g. Preparation of maleic anhydride-acrylic acid copolymer grafted polyethylene: the molar ratio of maleic anhydride to acrylic acid is 1:1.6, the mass fraction of benzoyl peroxide in total monomers is 0.9%, the reaction temperature is 78°C, and the reaction time is 7.5 hours; the compression section temperature during blending extrusion is 198°C, the metering section temperature is 203°C, the screw rotation speed is 420 rpm, and the residence time is 3.2 minutes. Preparation of dopamine-silane composite modified polyethylene: the ultrasonic dispersion time is 38 minutes, the vacuum drying temperature is 61°C, and the vacuum drying time is 5.5 hours; the mass fraction of dopamine hydrochloride in polyethylene resin is 4.5%; the mass fraction of γ-glycidoxypropyltrimethoxysilane in polydopamine modified polyethylene is 6.5%; the reflux reaction temperature is 82°C, the reflux reaction time is 5.5 hours, and the vacuum drying time is 13.5 hours. Fabric preparation: the mixing rotation speed is 1150 rpm, and the mixing time is 19 minutes; the melt section temperature during twin-screw extrusion is 186°C, the metering section temperature is 191°C, the spinning speed is 2400 m / min; the first stretching temperature is 98°C, and the stretching ratio is 3.2 times; the second stretching temperature is 118°C, and the stretching ratio is 2.1 times; the heat setting temperature is 168°C, and the heat setting time is 11.5 minutes; the pre-dyeing time is 11.5 minutes, the dyeing temperature is 82°C, and the dyeing time is 42 minutes; the mass concentration of the fixing agent is 3.8 g / L, the fixing time is 38 minutes, and the drying time is 9.5 minutes.

[0050] Example 3

[0051] The preparation method is the same as that in Example 1, except that the raw materials are weighed according to the mass percentage: polyethylene resin 810 g, maleic anhydride-acrylic acid copolymer grafted polyethylene 70 g, dopamine-silane composite modified polyethylene 50 g, magnesium stearate 18 g, antioxidant 12 g. Preparation of maleic anhydride-acrylic acid copolymer grafted polyethylene: the molar ratio of maleic anhydride to acrylic acid is 1:2, the mass of benzoyl peroxide is 1.1% of the total mass of monomers, the reaction temperature is 82°C, and the reaction time is 6.5 hours; the blending extrusion compression section temperature is 201°C, the metering section temperature is 206°C, the screw rotation speed is 480 rpm, and the residence time is 3.8 minutes. Preparation of dopamine-silane composite modified polyethylene: ultrasonic dispersion time is 32 minutes, vacuum drying temperature is 62°C, and time is 4.5 hours; the mass of dopamine hydrochloride is 3.2% of the mass of polyethylene resin; the mass of γ-glycidyl ether oxypropyl trimethoxysilane is 5.2% of the mass of polydopamine modified polyethylene; the reflux reaction temperature is 79°C, the time is 4.5 hours, and the vacuum drying time is 12.5 hours. Fabric preparation: mixing rotation speed is 1050 rpm, time is 16 minutes; double screw extrusion melting section is 183°C, metering section is 188°C, spinning speed is 2100 m / min; the first stretching is 92°C, 2.8 times; the second stretching is 112°C, 1.9 times; heat setting is 162°C, 10.5 minutes; dyeing pre-dyeing time is 10.5 minutes, dyeing temperature is 79°C, time is 39 minutes; fixing agent concentration is 3.2 g / L, fixing time is 32 minutes; drying time is 8.5 minutes.

[0052] Comparative Example 1 The preparation method is the same as that in Example 1, except that the raw materials are weighed according to the mass percentage: polyethylene resin 850 g, maleic anhydride-acrylic acid copolymer grafted polyethylene 70 g, magnesium stearate 20 g, antioxidant 15 g (lack of dopamine-silane composite modified polyethylene). Fabric preparation: no dopamine-silane composite modified polyethylene is added.

[0053] Comparative Example 2 The preparation method is the same as that in Example 1, except that the raw materials are weighed according to the mass percentage: polyethylene resin 830 g, maleic anhydride-acrylic acid copolymer grafted polyethylene 60 g, dopamine-silane composite modified polyethylene 80 g, magnesium stearate 22 g, antioxidant 15 g.

[0054] Comparative Example 3 The preparation method is the same as that in Example 1, except that the raw materials are weighed according to the mass percentage: polyethylene resin 800 g, maleic anhydride-acrylic acid copolymer grafted polyethylene 80 g, dopamine-silane composite modified polyethylene 60 g, magnesium stearate 20 g (lack of antioxidant).

[0055] II. Performance Test The polyethylene fabric prepared in the above Examples 1-3 and Comparative Examples 1-3 was subjected to performance testing according to the following method: 1. Rubbing fastness: tested according to GB / T 3920-2008 "Textiles - Colour fastness tests - Colour fastness to rubbing", using a rubbing fastness tester (model: Y571B), taking a 40 mm x 100 mm sample, rubbing the sample with dry rubbing cloth and wet rubbing cloth (containing distilled water) for 10 times, respectively, and then evaluating the color fastness grade (1-5 grade, 5 grade being the best) with a gray sample card (GB / T 251-2008) after rubbing.

[0056] 2. Washing fastness: tested according to GB / T 3921-2008 "Textiles - Colour fastness tests - Colour fastness to washing", using a washing fastness tester (model: SW-12A), taking a 50 mm x 150 mm sample and mixing it with standard detergent (concentration 0.15%) and steel beads (diameter 6 mm, number 50), washing at 49°C for 45 minutes, and then dehydrating and drying, and then evaluating the color change and staining grade (1-5 grade, 5 grade being the best) with a gray sample card.

[0057] 3. Washing dimensional change rate: tested according to GB / T 8629-2017 "Textiles - Household washing and drying procedures for test purposes", selecting 4N program (washing at 49°C, centrifugal dehydration), measuring the length and width of the sample before and after washing, and calculating the dimensional change rate (%) = (dimension after washing - dimension before washing) / dimension before washing x 100%.

[0058] 4. Breaking strength and elongation at break: tested according to GB / T 3917.3-2019 "Textiles - Determination of tensile properties of fabrics - Part 3: determination of breaking force and elongation at break (strip method)", using an electronic fabric strength tester (model: YG026H), taking a 200 mm x 50 mm sample, and recording the breaking strength (N) and elongation at break (%) at a stretching speed of 100 mm / min.

[0059] 5. Performance testing results: Table 1: Performance testing results of each example and comparative example

[0060] As can be seen from Table 1, the examples 1-3 of the present application significantly solve the problems of poor color fastness (rubbing and washing) and insufficient washing resistance of traditional polyethylene fabric due to weak polarity of molecular chain and low surface energy through synergistic effect of double modification. The specific analysis is as follows: from the rubbing color fastness, the dry rubbing and wet rubbing levels of examples 1-3 are all stable at 4.5 / 4.0 and above, which is much higher than that of the comparative examples (the rubbing color fastness of comparative example 1 without dopamine-silane is only 3.5 / 3.0, the rubbing color fastness of comparative example 2 with low maleic anhydride-acrylic acid ratio is 4.0 / 3.5, and the rubbing color fastness of comparative example 3 without antioxidant is 4.0 / 3.8). This is because the carboxyl and acrylate groups introduced by the maleic anhydride-acrylic acid copolymer form a bipolar group, which enhances the binding force through hydrogen bonding and dipole interaction with the dye molecules, and the catechol group in the dopamine-silane composite modification forms a coordination bond with the dye, and the three synergistically significantly improve the dyeing ability during rubbing.

[0061] In terms of washing color fastness, the color change and color bleeding levels of examples 1-3 are all maintained at about 4.5 / 4.2, which is much higher than that of the comparative examples (the color change of comparative example 1 is only 3.5, and the color bleeding is 3.2; the color change of comparative example 2 is 4.0, and the color bleeding is 3.8; the color change of comparative example 3 is 4.0, and the color bleeding is 3.9). This is because the epoxy groups formed after the hydrolysis of γ-glycidoxypropyltrimethoxysilane (GPTMS) in the dopamine-silane composite modification crosslink with the catechol groups to construct a three-dimensional network structure, which effectively inhibits the dye migration caused by fiber swelling during washing; at the same time, the hydrophobicity of the siloxane segment reduces the dissolution effect of water penetration on the dye, while the traditional polyethylene is prone to dye loss due to swelling because of its low surface energy and weak inter-fiber interaction.

[0062] In terms of washing size change rate, the shrinkage of examples 1-3 is only +1.1%~+1.3%, which is much lower than that of the comparative examples (the shrinkage of comparative example 1 is +3.5%, the shrinkage of comparative example 2 is +2.1%, and the shrinkage of comparative example 3 is +2.8%). This is because the dopamine-silane composite modification fixes the fiber morphology through the crosslinking network, and the hydrophobic barrier of the siloxane segment reduces the swelling-shrinking cycle caused by water penetration, while the traditional polyethylene is prone to size instability due to hygroscopic swelling because of its weak polarity of molecular chain and low crystallinity.

[0063] In terms of mechanical properties, the breaking strength (315~335N) and elongation at break (17.8%~19.2%) of examples 1-3 are all better than those of the comparative examples (the breaking strength is 280~310N, and the elongation at break is 16.2%~18.0%). This is because the bipolar groups of the maleic anhydride-acrylic acid copolymer enhance the interaction force between polyethylene molecular chains, and the dopamine-silane composite modification does not damage the original crystalline structure and processing fluidity of polyethylene, maintaining its light weight and durability.

[0064] In summary, examples 1-3 solve the problem of insufficient color fastness and wash resistance of traditional polyethylene fabrics through the multi-modification strategy of "polar group introduction, crosslinking network construction, and hydrophobic barrier formation", while retaining the basic mechanical advantages of polyethylene, achieving overall performance improvement.

[0065] The above embodiments only express several embodiments of the present application, and the description is more specific and detailed, but it cannot be understood as limiting the scope of the patent of the present application. It should be noted that for ordinary skilled persons in the art, without departing from the concept of the present application, several modifications and improvements can be made, which are within the protection scope of the present application.

Claims

1. A high color fastness, washable polyethylene fabric, characterized in that, According to mass percentage, raw materials include: Polyethylene resin: 78-85%; Maleic anhydride-acrylic acid copolymer grafted polyethylene: 7-10%; Dopamine-silane composite modified polyethylene: 5-8%; Magnesium stearate: 1.8-2.5%; Antioxidant: 1-1.5%; The preparation method of the maleic anhydride-acrylic acid copolymer grafted polyethylene includes: A1, maleic anhydride and acrylic acid are added into toluene solvent, nitrogen is introduced to remove oxygen, then benzoyl peroxide is added, the temperature is raised to 75-85℃ for reaction, after the reaction is completed, vacuum distillation is carried out to obtain maleic anhydride-acrylic acid copolymer; A2, then the maleic anhydride-acrylic acid copolymer is mixed with high-density polyethylene, and is added into a double-screw extruder, the extrusion temperature is set to 190-210℃, and the blended extrusion granulation is carried out.

2. The high color fastness wash durable polyethylene fabric of claim 1, wherein, In step A1, the molar ratio of maleic anhydride to acrylic acid is 1: (1.5-2), and the reaction time at 75-85℃ is 6-8h.

3. The high color fastness wash durable polyethylene fabric of claim 1, wherein, In step A2, the mass ratio of maleic anhydride-acrylic acid copolymer to high-density polyethylene is 1: (4-5), the compression section temperature in the double-screw extruder is 199-201℃, the metering section temperature is 204-206℃, the screw rotation speed is 400-500rpm, and the residence time for blended extrusion granulation is 3-4min.

4. The high color fastness wash durable polyethylene fabric of claim 1, wherein, The preparation method of the dopamine-silane composite modified polyethylene includes: B1, polyethylene resin particles are soaked in an ethanol-water mixed solution, silane coupling agent is added, ultrasonic dispersion is carried out, then the polyethylene resin particles are taken out, vacuum drying is carried out to obtain surface-hydroxylated polyethylene; then the surface-hydroxylated polyethylene and dopamine hydrochloride are added into a Tris-HCl buffer solution, magnetic stirring reaction is carried out at 24-26℃, after the reaction is completed, centrifugal washing is carried out, and vacuum drying is carried out at 40-42℃ to obtain polydopamine modified polyethylene; B2, the polydopamine modified polyethylene and γ-glycidoxypropyltrimethoxysilane are added into anhydrous ethanol, ultrasonic dispersion is carried out at 60-62℃, then the temperature is raised to 80-82℃ for reflux reaction, after the reaction is completed, vacuum distillation is carried out, and vacuum drying is carried out.

5. The high color fastness wash durable polyethylene fabric of claim 4, wherein, In step B1, the ultrasonic dispersion time is 30-40min, the vacuum drying temperature is 60-62℃, the vacuum drying time is 4-6h, dopamine hydrochloride accounts for 3-5% of the mass of the polyethylene resin, and the magnetic stirring reaction time is 24-26h.

6. The high color fastness wash durable polyethylene fabric of claim 4, wherein, In step B2, γ-glycidoxypropyltrimethoxysilane accounts for 5-7% of the mass of the polydopamine modified polyethylene, the ultrasonic dispersion time is 20-22min, the reflux reaction time at 80-82℃ is 4-6h, the vacuum drying temperature is 60-62℃, and the vacuum drying time is 12-14h.

7. A process for the production of a high colour fastness, washable polyethylene fabric according to any one of claims 1 to 6, characterised by the steps of S1, polyethylene resin, maleic anhydride-acrylic acid copolymer grafted polyethylene, dopamine-silane composite modified polyethylene, magnesium stearate and antioxidant are added into a high-speed mixer for mixing to obtain modified blended material; ​ S2, the modified blend is added into a twin-screw extruder for melt spinning, the extrusion temperature is set to 175-195℃, and the as-spun fiber is obtained after cooling; the as-spun fiber is stretched in two steps and heat set to form a polyester filament fabric grey cloth, wherein the first stretching temperature is 90-100℃, and the draw ratio is 3 times; the second stretching temperature is 110-120℃, and the draw ratio is 2 times; the heat setting temperature is 160-170℃; S3, the polyester filament fabric grey cloth is immersed in an active dyeing solution, pre-dyed at 60-62℃, dyed by increasing the temperature to 80-82℃, fixed by a fixing agent at 70-72℃ after washing, and finally dried at 100-102℃.

8. The preparation method according to claim 7, characterized in that, In step S1, the mixing speed is 1000-1200rpm, and the mixing time is 15-20min.

9. The preparation method according to claim 7, characterized in that, In step S2, the melt section temperature in the twin-screw extruder is 184-186℃, the metering section temperature is 189-191℃, the spinning speed is 2000-2500m / min, and the cooling air speed is 0.3-0.5m / s; the heat setting time is 10-12min.

10. The preparation method according to claim 7, characterized in that, In step S3, the concentration of the dye is 2-3g / L, the pre-dyeing time is 10-12min, the dyeing time at 80-82℃ is 40-42min; the concentration of the fixing agent is 3-4g / L; the fixing time at 70-72℃ is 30-40min; and the drying time at 100-102℃ is 8-10min.

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