Sun-shading composite fabric for vehicle sunroof and preparation method of sun-shading composite fabric

Abstract

The invention discloses a sunshade composite fabric for a vehicle skylight and a preparation method of the sunshade composite fabric, and relates to the technical field of composite fabrics. The composite fabric is of a three-layer structure and is obtained by sequentially attaching a surface layer, an anti-ultraviolet middle layer and a base cloth layer. The anti-ultraviolet middle layer is prepared from polyamide fibers, and the polyamide fibers are prepared from the following raw material components in parts by mass: 40 to 50 parts of polyhexamethylene adipamide, 40 to 50 parts of modified polycaprolactam, 5 to 8 parts of modified titanium dioxide, 1 to 2 parts of an antioxidant and 1 to 1.5 parts of a heat stabilizer. Polyhexamethylene adipamide, modified polycaprolactam, an antioxidant, modified titanium dioxide and a heat stabilizer are added into a spiral extrusion rod to be mixed, melt spinning and winding forming are conducted, and polyamide fibers are formed; and weaving to obtain the anti-ultraviolet middle layer. The prepared anti-ultraviolet middle layer has excellent ultraviolet resistance and impact resistance, and can achieve a certain roof protection effect while meeting the sunshading requirement of the composite fabric.

Description

Technical Field

[0001] The invention relates to the technical field of composite fabrics, in particular to a sunshade composite fabric for a vehicle sunroof and a preparation method thereof. Background Art

[0002] With the rapid development of the automotive industry, consumers have placed higher demands on the comfort, functionality, and aesthetics of vehicle interiors. Vehicle sunroofs, in particular, are widely used in vehicle design because they enhance interior lighting and ventilation, greatly improving the driving experience. However, during use, vehicles are sometimes exposed to direct sunlight, which increases the interior temperature and releases ultraviolet radiation, which in turn reduces the driving experience. Therefore, sunshades are often installed on sunroofs to block direct sunlight.

[0003] In the existing technology, since the skylight is located in a horizontal position, the sunshade material needs to be exposed to the sun for a longer time, and because of the influence of its own gravity, the commonly used vertical sunshade material is more likely to become brittle; in addition, in daily use, in order to improve ventilation, it may be necessary to open the skylight and use sunshade materials at the same time, so the sunshade material used for the skylight must also take into account certain protective functions of the roof, such as certain impact resistance, to block stones, branches, etc. on the road.

[0004] In summary, in order to solve the above problems, it is of great significance to prepare a sunshade composite fabric for vehicle sunroof. Summary of the Invention

[0005] The object of the present invention is to provide a sunshade composite fabric for a vehicle sunroof and a preparation method thereof, so as to solve the problems raised in the above background technology.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions: A sunshade composite fabric for a vehicle sunroof: the composite fabric has a three-layer structure, which is obtained by laminating a surface layer, an anti-ultraviolet middle layer, and a base fabric layer in sequence; The anti-ultraviolet intermediate layer is prepared from nylon fiber, and the raw materials of the nylon fiber include the following components: 40 to 50 parts of polyhexamethylene adipamide, 40 to 50 parts of modified polycaprolactam, 5 to 8 parts of modified titanium dioxide, 1 to 2 parts of antioxidant, and 1 to 1.5 parts of heat stabilizer in parts by mass.

[0007] More preferably, the preparation method of the anti-ultraviolet intermediate layer includes the following steps: adding polyhexamethylene adipamide, modified polycaprolactam, antioxidant, modified titanium dioxide, and heat stabilizer into a spiral extrusion rod for mixing, melt spinning, winding and forming to form nylon fiber; and weaving to obtain the anti-ultraviolet intermediate layer.

[0008] Preferably, the preparation method of the modified polycaprolactam comprises the following steps: (1) under a nitrogen atmosphere, adding 4,4'-dihydroxybiphenyl, di(4-hydroxyphenyl)acetic acid and triethylamine to anhydrous tetrahydrofuran and stirring evenly, slowly adding phenylphosphoryl dichloride dropwise in an ice-water bath and stirring to react for 2-2.5 hours, heating to 70-75°C, continuing to stir and react for 5-6 hours, adding hydroxyl-terminated dimethylsiloxane, continuing to stir and react for 10-12 hours, filtering, rotary evaporating to remove the solvent, washing, purifying and drying to obtain an anti-ultraviolet agent; (2) Add the anti-ultraviolet agent to anhydrous tetrahydrofuran and stir evenly, add 1,6-hexamethylene diisocyanate, stir at 60~70℃ for 1~1.5h, evaporate the solvent to obtain the modifier; (3) Heat caprolactam to 120~130℃, remove water, and divide it into two parts in half, add the modifier to one part and sodium hydroxide to the other part, stir each part for 10~15min, mix the two parts evenly, stir at 155~165℃ for 30~40min, transfer to a screw extrusion rod for extrusion granulation to obtain modified polycaprolactam.

[0009] Preferably, the anti-ultraviolet agent comprises the following raw materials, calculated by mass: 4.3-4.5 parts of 4,4'-dihydroxybiphenyl, 1.3-1.5 parts of di(4-hydroxyphenyl)acetic acid, 3.1-3.3 parts of triethylamine, 5.6-5.7 parts of phenylphosphoryl dichloride, and 4.8-5.2 parts of hydroxy-terminated dimethylsiloxane; The mass ratio of the anti-ultraviolet agent to hexamethylene diisocyanate is 10:0.45-0.55; The modified polycaprolactam comprises the following raw materials, calculated by mass: 100 parts of caprolactam, 4 to 6 parts of modifier, and 1.5 to 2 parts of sodium hydroxide.

[0010] Preferably, the molecular weight of the hydroxyl-terminated dimethylsiloxane is 3000-4000.

[0011] Preferably, the preparation method of the modified titanium dioxide comprises the following steps: (1) adding nano-titanium dioxide to deionized water for ultrasonic dispersion, adding anhydrous ethanol and 3-aminopropyltriethoxysilane, filtering, washing, and drying to obtain amino titanium dioxide; (2) adding amino titanium dioxide to toluene for ultrasonic dispersion, adding 1,6-hexamethylene diisocyanate under nitrogen atmosphere, stirring at 70-80°C for 1-1.5 hours, adding hydroxyl-terminated dimethylsiloxane, stirring at 75-85°C for 30-50 minutes, adding 1,4-butanediol, 4,4'-dihydroxybenzophenone and dibutyltin dilaurate, stirring at 80-90°C for 1-2 hours, filtering, washing, and drying to obtain modified titanium dioxide.

[0012] Preferably, the amino titanium dioxide comprises the following raw materials, calculated by mass: 1-2 parts of nano titanium dioxide, 30-40 parts of deionized water, 50-60 parts of anhydrous ethanol, and 0.4-0.6 parts of 3-aminopropyltriethoxysilane; The modified titanium dioxide comprises the following raw materials, calculated by mass: 1-2 parts of amino titanium dioxide, 40-50 parts of toluene, 10-12 parts of 1,6-hexamethylene diisocyanate, 25-28 parts of hydroxyl-terminated dimethylsiloxane, 2-3 parts of 1,4-butanediol, 3-4 parts of 4,4'-dihydroxybenzophenone, and 0.01-0.02 parts of dibutyltin dilaurate.

[0013] More preferably, during the weaving process, the fiber specifications are 35~50D / 72~96F.

[0014] More preferably, the method for preparing a sunshade composite fabric for a vehicle sunroof includes the following steps: coating hot melt adhesive on both sides of the anti-ultraviolet intermediate layer, stacking a surface layer on top of it, stacking a base fabric layer below it, hot pressing and curing, and drying to obtain the sunshade composite fabric for the vehicle sunroof.

[0015] Preferably, the surface layer is a PET aluminum-coated film with a thickness of 10-20 μm, wherein the thickness of the aluminum layer is 300-700 Å; the base fabric layer is a non-woven fabric with a thickness of 0.05-0.2 mm; During the hot pressing curing process, the temperature is 160-180° C., the pressure is 3-5 MPa, and the time is 1-3 minutes.

[0016] Compared with the existing technology, the beneficial effects achieved by the present invention are as follows: the sunshade composite fabric for vehicle sunroof provided by the present invention is obtained by laminating a surface layer, an anti-ultraviolet middle layer, and a base fabric layer, and the anti-ultraviolet middle layer is obtained by melt spinning and weaving modified polycaprolactam and polyhexamethylene adipamide, and a certain amount of modified titanium dioxide is added, and has excellent impact resistance and anti-ultraviolet properties.

[0017] Among them, the modified polycaprolactam is obtained by copolymerizing caprolactam with a modifier. The preparation process of the modifier is that 4,4'-dihydroxybiphenyl and di(4-hydroxyphenyl)acetic acid react and polymerize with phenylphosphoryl dichloride under the catalysis of triethylamine to form a phosphorus-containing activator, which reacts with one end of hydroxyl-terminated dimethylsiloxane to form an anti-ultraviolet agent containing a hydroxyl-terminated siloxane chain end, and further reacts with 1,6-hexamethylene diisocyanate to obtain the modifier. The introduction of a modifier through copolymerization introduces a polysiloxane structure, improving the toughness and impact resistance of polycaprolactam. The low surface energy of polysiloxane and its siloxy groups are chemically inert to UV radiation, which helps enhance the UV resistance of polycaprolactam. However, the molecular weight of polysiloxane needs to be limited to 3000-4000. Excessively large molecular weights restrict the movement of the molecular chain, reducing the material's impact resistance. Excessively small molecular weights can lead to microphase separation at the interface, reducing strength. The introduction of a phosphorus-containing activator significantly improves the material's UV resistance and thermal stability. Furthermore, the introduction of a rigid benzene-containing polymer segment synergizes with the tough structure of polysiloxane to enhance the impact resistance of polycaprolactam. Furthermore, the conjugated π electrons in the benzene ring absorb UV radiation to a certain extent, improving UV resistance. Furthermore, the carboxyl group structure of the introduced di(4-hydroxyphenyl)acetic acid promotes the ring opening of caprolactam, increasing polymerization efficiency and thus improving fiber performance.

[0018] Among them, the modified titanium dioxide is obtained by introducing amino groups with a silane coupling agent, adding 1,6-hexamethylene diisocyanate and hydroxyl-terminated dimethylsiloxane for reaction, and using 1,4-butanediol and 4,4'-dihydroxybenzophenone for chain extension; the addition of nano-titanium dioxide helps to greatly improve the material's UV resistance, and when the material is impacted, it can serve as a stress concentration point to absorb and disperse the stress under the action of external force, thereby improving impact resistance; and by introducing similar chain segments, the dispersibility of nano-titanium dioxide in the system is improved, and the benzophenone structure in 4,4'-dihydroxybenzophenone can further improve the material's UV resistance; thereby improving the material's UV resistance and impact resistance. DETAILED DESCRIPTION

[0019] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0020] It should be noted that the following parts are calculated by mass, and the purchase manufacturers of all raw materials involved in the present invention are not subject to any special restrictions. Examples include: CAS number of 4,4'-dihydroxybiphenyl: 92-88-6; CAS number of di(4-hydroxyphenyl)acetic acid: 40232-93-7; CAS number of triethylamine: 121-44-8; CAS number of phenylphosphoryl dichloride: 824-72-6; hydroxyl-terminated dimethylsiloxane, molecular weight 3000~4000; CAS number of 1,6-hexamethylene diisocyanate: : 822-06-0; CAS number of caprolactam: 105-60-2; polyhexamethylene adipamide, model ST801, provided by Suzhou Yunmi Plastics Co., Ltd.; nano titanium dioxide, particle size of 20~80nm; CAS number of 3-aminopropyltriethoxysilane: 919-30-2; CAS number of 4,4'-dihydroxybenzophenone: 611-99-4; CAS number of dibutyltin dilaurate: 77-58-7; In the following examples, the above-mentioned and other raw materials used but not mentioned were commercially available.

[0021] In each embodiment and comparative example, the antioxidant model is GA-80; the heat stabilizer model is H3337; the PET aluminized film has a thickness of 10-20 μm, wherein the thickness of the aluminum layer is 300-700 Å; the base fabric layer is a non-woven fabric with a thickness of 0.05-0.2 mm.

[0022] Example 1: A method for preparing a sunshade composite fabric for a vehicle sunroof comprises the following steps: Step 1: Preparation of modified polycaprolactam: (1) Under nitrogen atmosphere, add 4.4 parts of 4,4'-dihydroxybiphenyl, 1.4 parts of di(4-hydroxyphenyl)acetic acid, and 3.2 parts of triethylamine to 30 parts of anhydrous tetrahydrofuran and stir evenly, slowly add 5.65 parts of phenylphosphoryl dichloride dropwise in an ice-water bath and stir to react for 2 hours, heat to 70°C, continue stirring to react for 5 hours, add 5 parts of hydroxyl-terminated dimethylsiloxane, continue stirring to react for 12 hours, filter, evaporate the solvent by rotary evaporation, wash, purify, and dry to obtain an anti-ultraviolet agent; (2) Add the anti-ultraviolet agent to 30 parts of anhydrous tetrahydrofuran and stir evenly, add 1,6-hexamethylene diisocyanate at a mass ratio of 10:0.5 to the anti-ultraviolet agent, stir at 65°C for 1 hour, and evaporate the solvent to obtain a modifier; (3) Heat 100 parts of caprolactam to 125°C, remove water, and divide it into two parts. Add 5 parts of modifier to one part and 1.5 parts of sodium hydroxide to the other part. After stirring for 15 minutes, mix the two parts evenly, stir at 160°C for 35 minutes, and transfer to a screw extruder for extrusion and granulation to obtain modified polycaprolactam.

[0023] Step 2: Preparation of modified titanium dioxide: (1) Add 1.5 parts of nano-titanium dioxide to 35 parts of deionized water and disperse them uniformly by ultrasonication, then add 55 parts of anhydrous ethanol and 0.5 parts of 3-aminopropyltriethoxysilane, filter, wash and dry to obtain amino-modified titanium dioxide; (2) Add 1.5 parts of amino titanium dioxide to 45 parts of toluene and disperse uniformly by ultrasonication. Under a nitrogen atmosphere, add 11 parts of 1,6-hexamethylene diisocyanate and stir at 75°C for 1 hour. Add 26 parts of hydroxy-terminated dimethylsiloxane and stir at 80°C for 40 minutes. Add 2.5 parts of 1,4-butanediol, 3.5 parts of 4,4'-dihydroxybenzophenone and 0.01 parts of dibutyltin dilaurate and stir at 85°C for 1.5 hours. Filter, wash and dry to obtain modified titanium dioxide. Step 3: Preparation of UV-blocking fabric: 45 parts of polyhexamethylene adipamide, 45 parts of modified polycaprolactam, 6 parts of modified titanium dioxide, 1.5 parts of antioxidant, and 1 part of heat stabilizer are added to a spiral extruder, mixed, melt-spun, and wound to form nylon fibers; and woven to obtain a UV-resistant intermediate layer; wherein the fiber specification is 40D / 84F; Step 4: Preparation of sunshade composite fabric for vehicle sunroof: Coat hot melt adhesive on both sides of nylon light-shielding fabric, stack PET aluminum-coated film on top, stack non-woven fabric on the bottom, hot press at a pressure of 4 MPa and a temperature of 170°C for 2 minutes, and dry; obtain sunshade composite fabric for vehicle sunroof.

[0024] Example 2: A method for preparing a sunshade composite fabric for a vehicle sunroof comprises the following steps: Step 1: Preparation of modified polycaprolactam: (1) Under nitrogen atmosphere, add 4.4 parts of 4,4'-dihydroxybiphenyl, 1.4 parts of di(4-hydroxyphenyl)acetic acid, and 3.2 parts of triethylamine to 30 parts of anhydrous tetrahydrofuran and stir evenly, slowly add 5.65 parts of phenylphosphoryl dichloride dropwise in an ice-water bath and stir to react for 2 hours, heat to 70°C, continue stirring to react for 5 hours, add 5 parts of hydroxyl-terminated dimethylsiloxane, continue stirring to react for 12 hours, filter, evaporate the solvent by rotary evaporation, wash, purify, and dry to obtain an anti-ultraviolet agent; (2) Add the anti-ultraviolet agent to 30 parts of anhydrous tetrahydrofuran and stir evenly, add 1,6-hexamethylene diisocyanate at a mass ratio of 10:0.5 to the anti-ultraviolet agent, stir at 65°C for 1 hour, and evaporate the solvent to obtain a modifier; (3) Heat 100 parts of caprolactam to 125°C, remove water, and divide it into two parts. Add 5 parts of modifier to one part and 1.5 parts of sodium hydroxide to the other part. After stirring for 15 minutes, mix the two parts evenly, stir at 160°C for 35 minutes, and transfer to a screw extruder for extrusion and granulation to obtain modified polycaprolactam.

[0025] Step 2: Preparation of modified titanium dioxide: (1) Add 1.5 parts of nano-titanium dioxide to 35 parts of deionized water and disperse them uniformly by ultrasonication, then add 55 parts of anhydrous ethanol and 0.5 parts of 3-aminopropyltriethoxysilane, filter, wash and dry to obtain amino-modified titanium dioxide; (2) Add 1.5 parts of amino titanium dioxide to 45 parts of toluene and disperse uniformly by ultrasonication. Under a nitrogen atmosphere, add 11 parts of 1,6-hexamethylene diisocyanate and stir at 75°C for 1 hour. Add 26 parts of hydroxy-terminated dimethylsiloxane and stir at 80°C for 40 minutes. Add 2.5 parts of 1,4-butanediol, 3.5 parts of 4,4'-dihydroxybenzophenone and 0.01 parts of dibutyltin dilaurate and stir at 85°C for 1.5 hours. Filter, wash and dry to obtain modified titanium dioxide. Step 3: Preparation of UV-blocking fabric: 50 parts of polyhexamethylene adipamide, 50 parts of modified polycaprolactam, 8 parts of modified titanium dioxide, 2 parts of antioxidant, and 1.5 parts of heat stabilizer are added to a spiral extruder, mixed, melt-spun, and wound to form nylon fibers; and woven to obtain a UV-resistant intermediate layer; wherein the fiber specification is 35D / 96F; Step 4: Preparation of sunshade composite fabric for vehicle sunroof: Coat hot melt adhesive on both sides of nylon light-shielding fabric, stack PET aluminum-coated film on top, stack non-woven fabric on the bottom, hot press at a pressure of 4 MPa and a temperature of 170°C for 2 minutes, and dry; obtain sunshade composite fabric for vehicle sunroof.

[0026] Example 3: A method for preparing a sunshade composite fabric for a vehicle sunroof comprises the following steps: Step 1: Preparation of modified polycaprolactam: (1) Under nitrogen atmosphere, add 4.4 parts of 4,4'-dihydroxybiphenyl, 1.4 parts of di(4-hydroxyphenyl)acetic acid, and 3.2 parts of triethylamine to 30 parts of anhydrous tetrahydrofuran and stir evenly, slowly add 5.65 parts of phenylphosphoryl dichloride dropwise in an ice-water bath and stir to react for 2 hours, heat to 70°C, continue stirring to react for 5 hours, add 5 parts of hydroxyl-terminated dimethylsiloxane, continue stirring to react for 12 hours, filter, evaporate the solvent by rotary evaporation, wash, purify, and dry to obtain an anti-ultraviolet agent; (2) Add the anti-ultraviolet agent to 30 parts of anhydrous tetrahydrofuran and stir evenly, add 1,6-hexamethylene diisocyanate at a mass ratio of 10:0.5 to the anti-ultraviolet agent, stir at 65°C for 1 hour, and evaporate the solvent to obtain a modifier; (3) Heat 100 parts of caprolactam to 125°C, remove water, and divide it into two parts. Add 5 parts of modifier to one part and 1.5 parts of sodium hydroxide to the other part. After stirring for 15 minutes, mix the two parts evenly, stir at 160°C for 35 minutes, and transfer to a screw extruder for extrusion and granulation to obtain modified polycaprolactam.

[0027] Step 2: Preparation of modified titanium dioxide: (1) Add 1.5 parts of nano-titanium dioxide to 35 parts of deionized water and disperse them uniformly by ultrasonication, then add 55 parts of anhydrous ethanol and 0.5 parts of 3-aminopropyltriethoxysilane, filter, wash and dry to obtain amino-modified titanium dioxide; (2) Add 1.5 parts of amino titanium dioxide to 45 parts of toluene and disperse uniformly by ultrasonication. Under a nitrogen atmosphere, add 11 parts of 1,6-hexamethylene diisocyanate and stir at 75°C for 1 hour. Add 26 parts of hydroxy-terminated dimethylsiloxane and stir at 80°C for 40 minutes. Add 2.5 parts of 1,4-butanediol, 3.5 parts of 4,4'-dihydroxybenzophenone and 0.01 parts of dibutyltin dilaurate and stir at 85°C for 1.5 hours. Filter, wash and dry to obtain modified titanium dioxide. Step 3: Preparation of UV-blocking fabric: 40 parts of polyhexamethylene adipamide, 40 parts of modified polycaprolactam, 5 parts of modified titanium dioxide, 1 part of antioxidant, and 1 part of heat stabilizer are added to a spiral extruder, mixed, melt-spun, and wound to form nylon fibers; and woven to obtain a UV-resistant intermediate layer; wherein the fiber specification is 50D / 72F; Step 4: Preparation of sunshade composite fabric for vehicle sunroof: Coat hot melt adhesive on both sides of nylon light-shielding fabric, stack PET aluminum-coated film on top, stack non-woven fabric on the bottom, hot press at a pressure of 4 MPa and a temperature of 170°C for 2 minutes, and dry; obtain sunshade composite fabric for vehicle sunroof.

[0028] Comparative Example 1: Based on Example 1, the modified polycaprolactam was replaced with commercially available polycaprolactam, and the remaining processes remained unchanged, as follows: Step 1: Preparation of modified titanium dioxide: (1) Add 1.5 parts of nano-titanium dioxide to 35 parts of deionized water and disperse them uniformly by ultrasonication, then add 55 parts of anhydrous ethanol and 0.5 parts of 3-aminopropyltriethoxysilane, filter, wash and dry to obtain amino titanium dioxide; (2) Add 1.5 parts of amino titanium dioxide to 45 parts of toluene and disperse uniformly by ultrasonication. Under a nitrogen atmosphere, add 11 parts of 1,6-hexamethylene diisocyanate and stir at 75°C for 1 hour. Add 26 parts of hydroxy-terminated dimethylsiloxane and stir at 80°C for 40 minutes. Add 2.5 parts of 1,4-butanediol, 3.5 parts of 4,4'-dihydroxybenzophenone and 0.01 parts of dibutyltin dilaurate and stir at 85°C for 1.5 hours. Filter, wash and dry to obtain modified titanium dioxide. Step 2: Preparation of UV-blocking fabric: 45 parts of polyhexamethylene adipamide, 45 parts of polycaprolactam, 6 parts of modified titanium dioxide, 1.5 parts of antioxidant, and 1 part of heat stabilizer are added to a spiral extruder, mixed, melt-spun, and wound to form nylon fibers; and woven to obtain a UV-resistant intermediate layer; wherein the fiber specification is 40D / 84F; Step 3: Preparation of sunshade composite fabric for vehicle sunroof: Coat hot melt adhesive on both sides of nylon light-shielding fabric, stack PET aluminum-coated film on top, stack non-woven fabric on the bottom, hot press at a pressure of 4 MPa and a temperature of 170°C for 2 minutes, and dry; obtain sunshade composite fabric for vehicle sunroof.

[0029] Comparative Example 2: Based on Example 1, di(4-hydroxyphenyl)acetic acid was not added during the preparation of the modified polycaprolactam, and the remaining processes remained unchanged, as follows: Step 1: Preparation of modified polycaprolactam: (1) Under a nitrogen atmosphere, add 5.8 parts of 4,4'-dihydroxybiphenyl and 3.2 parts of triethylamine to 30 parts of anhydrous tetrahydrofuran and stir evenly, slowly dropwise add 5.65 parts of phenylphosphoryl dichloride in an ice-water bath and stir to react for 2 hours, heat to 70°C, continue stirring to react for 5 hours, add 5 parts of hydroxyl-terminated dimethylsiloxane, continue stirring to react for 12 hours, filter, evaporate the solvent by rotary evaporation, wash, purify, and dry to obtain an anti-ultraviolet agent; (2) Add the anti-ultraviolet agent to 30 parts of anhydrous tetrahydrofuran and stir evenly, add 1,6-hexamethylene diisocyanate at a mass ratio of 10:0.5 to the anti-ultraviolet agent, stir at 65°C for 1 hour, and evaporate the solvent to obtain a modifier; (3) Heat 100 parts of caprolactam to 125°C, remove water, and divide it into two parts. Add 5 parts of modifier to one part and 1.5 parts of sodium hydroxide to the other part. After stirring for 15 minutes, mix the two parts evenly, stir at 160°C for 35 minutes, and transfer to a screw extruder for extrusion and granulation to obtain modified polycaprolactam.

[0030] Step 2: Preparation of modified titanium dioxide: (1) Add 1.5 parts of nano-titanium dioxide to 35 parts of deionized water and disperse them uniformly by ultrasonication, then add 55 parts of anhydrous ethanol and 0.5 parts of 3-aminopropyltriethoxysilane, filter, wash and dry to obtain amino-modified titanium dioxide; (2) Add 1.5 parts of amino titanium dioxide to 45 parts of toluene and disperse uniformly by ultrasonication. Under a nitrogen atmosphere, add 11 parts of 1,6-hexamethylene diisocyanate and stir at 75°C for 1 hour. Add 26 parts of hydroxy-terminated dimethylsiloxane and stir at 80°C for 40 minutes. Add 2.5 parts of 1,4-butanediol, 3.5 parts of 4,4'-dihydroxybenzophenone and 0.01 parts of dibutyltin dilaurate and stir at 85°C for 1.5 hours. Filter, wash and dry to obtain modified titanium dioxide. Step 3: Preparation of UV-blocking fabric: 45 parts of polyhexamethylene adipamide, 45 parts of modified polycaprolactam, 6 parts of modified titanium dioxide, 1.5 parts of antioxidant, and 1 part of heat stabilizer are added to a spiral extruder, mixed, melt-spun, and wound to form nylon fibers; and woven to obtain a UV-resistant intermediate layer; wherein the fiber specification is 40D / 84F; Step 4: Preparation of sunshade composite fabric for vehicle sunroof: Coat hot melt adhesive on both sides of nylon light-shielding fabric, stack PET aluminum-coated film on top, stack non-woven fabric on the bottom, hot press at a pressure of 4 MPa and a temperature of 170°C for 2 minutes, and dry; obtain sunshade composite fabric for vehicle sunroof.

[0031] Comparative Example 3: Based on Example 1, the molecular weight of hydroxyl-terminated dimethylsiloxane was increased to 5000, and the other processes remained unchanged, as follows: Step 1: Preparation of modified polycaprolactam: (1) Under nitrogen atmosphere, add 4.4 parts of 4,4'-dihydroxybiphenyl, 1.4 parts of di(4-hydroxyphenyl)acetic acid, and 3.2 parts of triethylamine to 30 parts of anhydrous tetrahydrofuran and stir evenly, slowly add 5.65 parts of phenylphosphoryl dichloride dropwise in an ice-water bath and stir to react for 2 hours, heat to 70°C, continue stirring to react for 5 hours, add 5 parts of hydroxyl-terminated dimethylsiloxane (molecular weight 5000), continue stirring to react for 12 hours, filter, evaporate the solvent by rotary evaporation, wash, purify, and dry to obtain an anti-ultraviolet agent; (2) Add the anti-ultraviolet agent to 30 parts of anhydrous tetrahydrofuran and stir evenly, add 1,6-hexamethylene diisocyanate at a mass ratio of 10:0.5 to the anti-ultraviolet agent, stir at 65°C for 1 hour, and evaporate the solvent to obtain a modifier; (3) Heat 100 parts of caprolactam to 125°C, remove water, and divide it into two parts. Add 5 parts of modifier to one part and 1.5 parts of sodium hydroxide to the other part. After stirring for 15 minutes, mix the two parts evenly, stir at 160°C for 35 minutes, and transfer to a screw extruder for extrusion and granulation to obtain modified polycaprolactam.

[0032] Step 2: Preparation of modified titanium dioxide: (1) Add 1.5 parts of nano-titanium dioxide to 35 parts of deionized water and disperse them uniformly by ultrasonication, then add 55 parts of anhydrous ethanol and 0.5 parts of 3-aminopropyltriethoxysilane, filter, wash and dry to obtain amino-modified titanium dioxide; (2) Add 1.5 parts of amino titanium dioxide to 45 parts of toluene and disperse uniformly by ultrasonication. Under a nitrogen atmosphere, add 11 parts of 1,6-hexamethylene diisocyanate and stir at 75°C for 1 hour. Add 26 parts of hydroxy-terminated dimethylsiloxane and stir at 80°C for 40 minutes. Add 2.5 parts of 1,4-butanediol, 3.5 parts of 4,4'-dihydroxybenzophenone and 0.01 parts of dibutyltin dilaurate and stir at 85°C for 1.5 hours. Filter, wash and dry to obtain modified titanium dioxide. Step 3: Preparation of UV-blocking fabric: 45 parts of polyhexamethylene adipamide, 45 parts of modified polycaprolactam, 6 parts of modified titanium dioxide, 1.5 parts of antioxidant, and 1 part of heat stabilizer are added to a spiral extruder, mixed, melt-spun, and wound to form nylon fibers; and woven to obtain a UV-resistant intermediate layer; wherein the fiber specification is 40D / 84F; Step 4: Preparation of sunshade composite fabric for vehicle sunroof: Coat hot melt adhesive on both sides of nylon light-shielding fabric, stack PET aluminum-coated film on top, stack non-woven fabric on the bottom, hot press at a pressure of 4 MPa and a temperature of 170°C for 2 minutes, and dry; obtain sunshade composite fabric for vehicle sunroof.

[0033] Comparative Example 4: Based on Example 1, the nano-titanium dioxide was only subjected to amination, and the rest of the process remained unchanged, as follows: Step 1: Preparation of modified polycaprolactam: (1) Under nitrogen atmosphere, add 4.4 parts of 4,4'-dihydroxybiphenyl, 1.4 parts of di(4-hydroxyphenyl)acetic acid, and 3.2 parts of triethylamine to 30 parts of anhydrous tetrahydrofuran and stir evenly, slowly add 5.65 parts of phenylphosphoryl dichloride dropwise in an ice-water bath and stir to react for 2 hours, heat to 70°C, continue stirring to react for 5 hours, add 5 parts of hydroxyl-terminated dimethylsiloxane, continue stirring to react for 12 hours, filter, evaporate the solvent by rotary evaporation, wash, purify, and dry to obtain an anti-ultraviolet agent; (2) Add the anti-ultraviolet agent to 30 parts of anhydrous tetrahydrofuran and stir evenly, add 1,6-hexamethylene diisocyanate at a mass ratio of 10:0.5 to the anti-ultraviolet agent, stir at 65°C for 1 hour, and evaporate the solvent to obtain a modifier; (3) Heat 100 parts of caprolactam to 125°C, remove water, and divide it into two parts. Add 5 parts of modifier to one part and 1.5 parts of sodium hydroxide to the other part. After stirring for 15 minutes, mix the two parts evenly, stir at 160°C for 35 minutes, and transfer to a screw extruder for extrusion and granulation to obtain modified polycaprolactam.

[0034] Step 2: Preparation of modified titanium dioxide: (1) Add 1.5 parts of nano-titanium dioxide to 35 parts of deionized water and disperse them uniformly by ultrasonication, then add 55 parts of anhydrous ethanol and 0.5 parts of 3-aminopropyltriethoxysilane, filter, wash and dry to obtain modified titanium dioxide; Step 3: Preparation of UV-blocking fabric: 45 parts of polyhexamethylene adipamide, 45 parts of modified polycaprolactam, 6 parts of modified titanium dioxide, 1.5 parts of antioxidant, and 1 part of heat stabilizer are added to a spiral extruder, mixed, melt-spun, and wound to form nylon fibers; and woven to obtain a UV-resistant intermediate layer; wherein the fiber specification is 40D / 84F; Step 4: Preparation of sunshade composite fabric for vehicle sunroof: Coat hot melt adhesive on both sides of nylon light-shielding fabric, stack PET aluminum-coated film on top, stack non-woven fabric on the bottom, hot press at a pressure of 4 MPa and a temperature of 170°C for 2 minutes, and dry; obtain sunshade composite fabric for vehicle sunroof.

[0035] Performance Test 1: Prepare the anti-ultraviolet intermediate layer according to the scheme of Example 1, and take samples for the following tests; (1) Test the breaking strength of the sample according to GB / T 3923.1-2013. After the test, the sample is subjected to ultraviolet light test according to ASTM G154. Under UVA-340 lamp, the irradiation intensity is 0.69W / m 2 The samples were irradiated for 30 days, the breaking strength was measured, and the breaking strength reduction rate was calculated; (2) the notched impact strength of the samples was tested according to T1043-2008; (3) the limiting oxygen index (LOI) of the samples was tested according to ISO 4589-2; (4) the samples were tested using a thermogravimetric analyzer, and the temperature at which 10% of the mass was lost was recorded, with a heating rate of 20°C / min and a maximum temperature of 600°C; (5) the transmittance of the samples at ultraviolet wavelengths of 280~320nm was measured according to GB / T18830-2009; the experimental data are shown in Table 1: Table 1 project Example 1 Breaking strength 3632 Breaking strength reduction rate / % 0.27 <![CDATA[Impact strength / kJ·m -2 > 27.7 Loss of 10wt% temperature / ℃ 339 LOI 27.8 UV transmittance / % 0.82 As can be seen from Table 1, the anti-ultraviolet intermediate layer prepared in the present invention has excellent ultraviolet resistance and impact resistance, and has certain flame retardancy and thermal stability.

[0036] Performance Test 2: Prepare the anti-ultraviolet intermediate layer according to the scheme of each embodiment and comparative example, and take samples for the following tests; (1) Test the breaking strength of the sample according to GB / T 3923.1-2013. After the test, the sample is subjected to ultraviolet light test according to ASTM G154. Under UVA-340 lamp, the irradiation intensity is 0.69W / m 2 The samples were irradiated for 30 days, the breaking strength was measured, and the breaking strength reduction rate was calculated; (2) the samples were tested for notched impact strength according to T1043-2008; the experimental data are shown in Table 2: Table 2 project Breaking strength reduction rate / % Impact strength / kJ·m-2 Example 1 0.27 27.7 Example 2 0.42 26.7 Example 3 0.51 26.2 Comparative Example 1 1.94 21.2 Comparative Example 2 0.76 25.4 Comparative Example 3 1.32 23.4 Comparative Example 4 0.92 24.6 As shown in Table 2, when the commercially purchased polycaprolactam was used in Comparative Example 1, the rate of decrease in breaking strength increased and the impact strength decreased, indicating that the modified polycaprolactam prepared by the present invention can significantly improve the UV resistance and impact resistance; in Comparative Example 2, no di(4-hydroxyphenyl)acetic acid was added, and its UV resistance and impact resistance decreased slightly, indicating that the addition of di(4-hydroxyphenyl)acetic acid promoted the ring-opening polymerization of polycaprolactam to a certain extent and enhanced the performance; in Comparative Example 3, the molecular weight of the hydroxyl-terminated dimethylsiloxane was increased, the movement of the molecular chain was restricted, and the impact resistance of the material was reduced; in Comparative Example 4, the nano-titanium dioxide was only amino-treated, and the dispersibility in the material decreased, so the UV resistance and impact resistance were reduced.

[0037] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or substitute equivalents for some of the technical features. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A sunshade composite fabric for a vehicle sunroof, characterized by: The composite fabric has a three-layer structure, which is obtained by laminating a surface layer, an anti-ultraviolet middle layer, and a base fabric layer in sequence; The anti-ultraviolet intermediate layer is prepared from nylon fiber, and the raw materials of the nylon fiber include the following components: 40 to 50 parts of polyhexamethylene adipamide, 40 to 50 parts of modified polycaprolactam, 5 to 8 parts of modified titanium dioxide, 1 to 2 parts of antioxidant, and 1 to 1.5 parts of heat stabilizer in parts by mass.

2. The sunshade composite fabric for a vehicle sunroof according to claim 1, characterized in that: The preparation method of the anti-ultraviolet intermediate layer comprises the following steps: adding polyhexamethylene adipamide, modified polycaprolactam, antioxidant, modified titanium dioxide and heat stabilizer into a spiral extrusion rod for mixing, melt spinning, winding and forming to form nylon fiber; and weaving to obtain the anti-ultraviolet intermediate layer.

3. The sunshade composite fabric for a vehicle sunroof according to claim 1, characterized in that: The preparation method of the modified polycaprolactam comprises the following steps: (1) adding 4,4'-dihydroxybiphenyl, di(4-hydroxyphenyl)acetic acid and triethylamine to anhydrous tetrahydrofuran under a nitrogen atmosphere and stirring evenly, slowly adding phenylphosphoryl dichloride dropwise in an ice-water bath and stirring to react for 2-2.5 hours, heating to 70-75°C, continuing stirring to react for 5-6 hours, adding hydroxyl-terminated dimethylsiloxane, continuing stirring to react for 10-12 hours, filtering, rotary evaporating to remove the solvent, washing, purifying and drying to obtain an anti-ultraviolet agent; (2) Add the anti-ultraviolet agent to anhydrous tetrahydrofuran and stir evenly, add 1,6-hexamethylene diisocyanate, stir at 60~70℃ for 1~1.5h, evaporate the solvent to obtain the modifier; (3) heat the caprolactam to 120~130℃, remove water, and divide it into two parts in half, add the modifier to one part and sodium hydroxide to the other part, stir for 10~15min each, mix the two parts evenly, stir at 155~165℃ for 30~40min, transfer to a screw extruder for extrusion and granulation to obtain modified polycaprolactam.

4. The sunshade composite fabric for a vehicle sunroof according to claim 3, characterized in that: The anti-ultraviolet agent comprises the following raw materials, calculated by mass: 4.3-4.5 parts of 4,4'-dihydroxybiphenyl, 1.3-1.5 parts of di(4-hydroxyphenyl)acetic acid, 3.1-3.3 parts of triethylamine, 5.6-5.7 parts of phenylphosphoryl dichloride, and 4.8-5.2 parts of hydroxyl-terminated dimethylsiloxane; The mass ratio of the anti-ultraviolet agent to hexamethylene diisocyanate is 10:0.45-0.55; The modified polycaprolactam comprises the following raw materials, calculated by mass: 100 parts of caprolactam, 4 to 6 parts of modifier, and 1.5 to 2 parts of sodium hydroxide.

5. The sunshade composite fabric for a vehicle sunroof according to claim 3, characterized in that: The molecular weight of the hydroxyl-terminated dimethylsiloxane is 3000-4000.

6. The sunshade composite fabric for a vehicle sunroof according to claim 1, characterized in that: The preparation method of the modified titanium dioxide comprises the following steps: (1) adding nano-titanium dioxide to deionized water and ultrasonically dispersing the mixture uniformly, adding anhydrous ethanol and 3-aminopropyltriethoxysilane, filtering, washing, and drying to obtain amino-treated titanium dioxide; (2) adding amino-treated titanium dioxide to toluene and ultrasonically dispersing the mixture uniformly, adding 1,6-hexamethylene diisocyanate under a nitrogen atmosphere, stirring the mixture at 70-80°C for 1-1.5 hours, adding hydroxyl-terminated dimethylsiloxane, stirring the mixture at 75-85°C for 30-50 minutes, adding 1,4-butanediol, 4,4'-dihydroxybenzophenone and dibutyltin dilaurate, stirring the mixture at 80-90°C for 1-2 hours, filtering, washing, and drying to obtain modified titanium dioxide.

7. The sunshade composite fabric for a vehicle sunroof according to claim 6, characterized in that: in, The amination titanium dioxide comprises the following raw materials, calculated by mass: 1-2 parts of nano titanium dioxide, 30-40 parts of deionized water, 50-60 parts of anhydrous ethanol, and 0.4-0.6 parts of 3-aminopropyltriethoxysilane; The modified titanium dioxide comprises the following raw materials, calculated by mass: 1-2 parts of amino titanium dioxide, 40-50 parts of toluene, 10-12 parts of 1,6-hexamethylene diisocyanate, 25-28 parts of hydroxyl-terminated dimethylsiloxane, 2-3 parts of 1,4-butanediol, 3-4 parts of 4,4'-dihydroxybenzophenone, and 0.01-0.02 parts of dibutyltin dilaurate.

8. The sunshade composite fabric for a vehicle sunroof according to claim 2, characterized in that: During the weaving process, the fiber specifications are 35~50D / 72~96F.

9. The method for preparing a sunshade composite fabric for a vehicle sunroof according to any one of claims 1 to 8, characterized in that: The following steps are involved: Hot melt adhesive is coated on both sides of the anti-ultraviolet middle layer, a surface layer is stacked on top of the middle layer, a base fabric layer is stacked below the middle layer, hot pressing and curing are performed, and drying is performed to obtain a sunshade composite fabric for a vehicle sunroof.

10. The method for preparing a sunshade composite fabric for a vehicle sunroof according to claim 9, characterized in that: The surface layer is a PET aluminum-plated film with a thickness of 10-20 μm, wherein the thickness of the aluminum layer is 300-700 Å; the base fabric layer is a non-woven fabric with a thickness of 0.05-0.2 mm; During the hot pressing curing process, the temperature is 160-180° C., the pressure is 3-5 MPa, and the time is 1-3 minutes.