A sunroof tpu type heat insulation film and a preparation process thereof

Abstract

The application relates to the technical field of polyurethane, and discloses a TPU type heat insulation film for a sunroof and a preparation process thereof. Polyurethane resin and modified mesoporous titanium dioxide are mixed, melted and extruded through an extruder, granulated, blown into a film through a film blowing machine, and the TPU type heat insulation film for the sunroof is obtained. The modified titanium dioxide contains urethane groups, the compatibility with polyurethane is good, the modified titanium dioxide can be uniformly dispersed in a polyurethane film matrix, the heat conductivity coefficient and the yellowing index of the film material are significantly reduced, the heat insulation and ultraviolet resistance are improved, meanwhile, the urethane groups contained in the modified mesoporous titanium dioxide and the urethane groups of the polyurethane form hydrogen bond interaction force, the interface bonding force of the two is increased, the polyurethane film has high tensile strength and excellent mechanical properties, and the polyurethane film has good practical application in automobile sunroofs, building daylighting roofs and the like.

Description

Technical Field

[0001] This invention relates to the field of polyurethane technology, specifically to a TPU-type heat insulation film for sunroofs and its preparation process. Background Technology

[0002] Polyurethane film materials possess excellent elasticity, mechanical strength, abrasion resistance, and waterproof properties, and are widely used in automotive window tinting, window film, and mobile phone screen protectors. However, ordinary polyurethane film materials have a relatively high thermal conductivity, poor heat insulation performance, and poor UV resistance, making them prone to yellowing, which affects the appearance and performance of the film material.

[0003] Nano-titanium dioxide exhibits excellent UV resistance, high mechanical strength, and certain heat reflectivity, making it a promising candidate for thermal insulation materials. Adding titanium dioxide to polyurethane materials can improve its UV resistance, weather resistance, and strength. However, addressing the agglomeration and dispersion of titanium dioxide remains a research challenge. Patent CN120248396B discloses an infrared-shielding polyurethane glass film and its preparation method, using tungsten-doped titanium dioxide, chloropropyltriethoxysilane, polyurethane, and functionalized crosslinking agents as raw materials. The resulting polyurethane glass film possesses good infrared shielding and anti-aging properties. However, this patent does not reduce the thermal conductivity of the polyurethane film, which is detrimental to the practical application of polyurethane in thermal insulation materials. Summary of the Invention

[0004] The technical problem solved by this invention is to address the poor compatibility between nano-titanium dioxide and polyurethane, and to improve the heat insulation and UV resistance properties of polyurethane membrane materials.

[0005] The technical solution of this invention: A preparation process for a TPU-type heat insulation film for sunroofs:

[0006] (1) Add mesoporous titanium dioxide to the solvent, disperse it by ultrasonication in an ultrasonic instrument, and then add N-benzyloxycarbonyl-3,4-dihydroxyphenylethylamine. Control the ratio of mesoporous titanium dioxide to N-benzyloxycarbonyl-3,4-dihydroxyphenylethylamine to be 100g: (4-12)g. Stir to modify, filter, wash with water and ethanol in sequence, and dry to obtain modified mesoporous titanium dioxide.

[0007] (2) A polyurethane resin and modified mesoporous titanium dioxide in a ratio of 100:(2-8) are mixed, melt-extruded by an extruder, granulated, and then blown into a film by a blown film machine to obtain a TPU type heat insulation film for sunroof.

[0008] Furthermore, in (1), the solvent is an aqueous solution of ethanol with a volume fraction of 50-80%.

[0009] Furthermore, the ultrasonic dispersion time in (1) is 20-40 min.

[0010] Furthermore, in (1), the temperature during modification is 15-30℃ and the time is 6-12h.

[0011] Furthermore, in (2), the temperature of the extruder in sections 1-5 is 140-190℃, and the screw speed is 30-60r / min.

[0012] Furthermore, (2) the temperature of the blown film machine in sections 1-3 is 160-185℃.

[0013] The beneficial technical effects of this invention are as follows: The catechol structure of N-benzyloxycarbonyl-3,4-dihydroxyphenylethylamine coordinates titanium atoms on the surface of mesoporous titanium dioxide, achieving surface modification of the mesoporous titanium dioxide. This improves the dispersibility and agglomeration defects of titanium dioxide. Simultaneously, the modified titanium dioxide contains urethane groups, which improves its compatibility with polyurethane, allowing it to be uniformly dispersed in the polyurethane film matrix. This significantly reduces the thermal conductivity and yellowing index of the film material, improving its heat insulation and UV resistance. Furthermore, the urethane groups in the modified mesoporous titanium dioxide form hydrogen bonds with the urethane groups in the polyurethane, increasing the interfacial bonding force and thus maintaining high tensile strength and excellent mechanical properties in the polyurethane film. This makes it well-suited for practical applications in automotive sunroofs and building skylights. Detailed Implementation

[0014] The technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0015] The following polyurethane resin model is IS-03, manufactured by Hubei Nanlong Elastomer Materials Co., Ltd.

[0016] The structural formula of N-benzyloxycarbonyl-3,4-dihydroxyphenylethylamine is: It was prepared according to the method described in the journal Carbohydrate Research 327 (2000) 353-365, in the article "Synthesis and biological studies of glycosyl dopamine derivatives as potential antiparkinsonia agents".

[0017] Mesoporous titanium dioxide was prepared according to the method described in the article "Synthesis and Characterization of Spherical Mesoporous Titanium Dioxide" in the journal "Water Treatment Technology" (Vol. 46, No. 5, May 2020).

[0018] Example 1

[0019] (1) Add 30g of mesoporous titanium dioxide to 1.5L of 60% ethanol aqueous solution, ultrasonically disperse it in an ultrasonic instrument for 20min, then add 1.2g of N-benzyloxycarbonyl-3,4-dihydroxyphenylethylamine, stir at 25℃ for 6h for modification, filter, wash with water and ethanol in sequence, and dry to obtain modified mesoporous titanium dioxide.

[0020] (2) Mix 1kg of polyurethane resin and 20g of modified mesoporous titanium dioxide, melt extrude through an extruder, with the temperatures of sections 1-5 being 140℃, 160℃, 180℃, 190℃, and 195℃, and the screw speed being 50r / min, granulate, and then blow mold into a film through a blown film machine, with the temperatures of sections 1-3 of the blown film machine being 160℃, 185℃, and 180℃, to obtain a TPU type heat insulation film for sunroofs.

[0021] Example 2

[0022] (1) Add 30g of mesoporous titanium dioxide to 1.5L of 80% ethanol aqueous solution, ultrasonically disperse it for 30min in an ultrasonic instrument, then add 2g of N-benzyloxycarbonyl-3,4-dihydroxyphenylethylamine, stir at 15℃ for 12h for modification, filter, wash with water and ethanol in sequence, and dry to obtain modified mesoporous titanium dioxide.

[0023] (2) Mix 1kg of polyurethane resin and 40g of modified mesoporous titanium dioxide, melt extrude through an extruder, with the temperatures of sections 1-5 being 140℃, 160℃, 180℃, 190℃, and 195℃, and the screw speed being 30r / min, granulate, and then blow mold into a film through a blown film machine, with the temperatures of sections 1-3 of the blown film machine being 160℃, 185℃, and 180℃, to obtain a TPU type heat insulation film for sunroofs.

[0024] Example 3

[0025] (1) Add 30g of mesoporous titanium dioxide to 2L of 50% ethanol aqueous solution, ultrasonically disperse it in an ultrasonic instrument for 40min, then add 2.8g of N-benzyloxycarbonyl-3,4-dihydroxyphenylethylamine, stir at 30℃ for 10h for modification, filter, wash with water and ethanol in sequence, and dry to obtain modified mesoporous titanium dioxide.

[0026] (2) Mix 1kg of polyurethane resin and 60g of modified mesoporous titanium dioxide, melt extrude through an extruder, with the temperatures of sections 1-5 being 140℃, 160℃, 180℃, 190℃, and 195℃, and the screw speed being 60r / min, granulate, and then blow mold into a film through a blown film machine, with the temperatures of sections 1-3 of the blown film machine being 160℃, 185℃, and 180℃, to obtain a TPU type heat insulation film for sunroofs.

[0027] Example 4

[0028] (1) Add 30g of mesoporous titanium dioxide to 2L of 80% ethanol aqueous solution, ultrasonically disperse it in an ultrasonic instrument for 40min, then add 3.6g of N-benzyloxycarbonyl-3,4-dihydroxyphenylethylamine, stir at 25℃ for 12h for modification, filter, wash with water and ethanol in sequence, and dry to obtain modified mesoporous titanium dioxide.

[0029] (2) Mix 1kg of polyurethane resin and 80g of modified mesoporous titanium dioxide, melt extrude through an extruder, with the temperatures of sections 1-5 being 140℃, 160℃, 180℃, 190℃, and 195℃, and the screw speed being 50r / min, granulate, and then blow mold into a film through a blown film machine, with the temperatures of sections 1-3 of the blown film machine being 160℃, 185℃, and 180℃, to obtain a TPU type heat insulation film for sunroofs.

[0030] Comparative Example 1

[0031] (1) Mix 1kg of polyurethane resin and 20g of mesoporous titanium dioxide, melt extrude through an extruder, with the temperatures of sections 1-5 being 140℃, 160℃, 180℃, 190℃, and 195℃, and the screw speed being 50r / min, granulate, and then blow mold into a film through a blown film machine, with the temperatures of sections 1-3 of the blown film machine being 160℃, 185℃, and 180℃, to obtain a TPU type heat insulation film.

[0032] Comparative Example 2

[0033] (1) Add 30g of mesoporous titanium dioxide to 1.5L of water, sonicate it for 20min in an ultrasonic instrument, then add 1.2g of dopamine hydrochloride, add 0.9mL of Tris hydrochloride buffer solution, stir at 25℃ for 6h for modification, filter, wash with water and ethanol in sequence, dry, and obtain modified mesoporous titanium dioxide.

[0034] (2) Mix 1kg of polyurethane resin and 20g of modified mesoporous titanium dioxide, melt extrude through an extruder, with the temperatures of sections 1-5 being 140℃, 160℃, 180℃, 190℃, and 195℃, and the screw speed being 50r / min, granulate, and then blow mold into a film through a blown film machine, with the temperatures of sections 1-3 of the blown film machine being 160℃, 185℃, and 180℃, to obtain a TPU type heat insulation film.

[0035] Comparative Example 3

[0036] (1) Add 30g of mesoporous titanium dioxide to 1.5L of toluene, sonicate it for 20min in an ultrasonic instrument, then add 1.2g of diphenylmethane-4,4'-diisocyanate, stir at 90℃ for 6h for modification, filter, wash with ethanol, and dry to obtain modified mesoporous titanium dioxide.

[0037] (2) Mix 1kg of polyurethane resin and 20g of modified mesoporous titanium dioxide, melt extrude through an extruder, with the temperatures of sections 1-5 being 140℃, 160℃, 180℃, 190℃, and 195℃, and the screw speed being 50r / min, granulate, and then blow mold into a film through a blown film machine, with the temperatures of sections 1-3 of the blown film machine being 160℃, 185℃, and 180℃, to obtain a TPU type heat insulation film.

[0038] The thermal conductivity of TPU type heat insulation film is tested according to GB / T 3399-1982 standard.

[0039] The TPU heat insulation film was placed in a UV aging test chamber (power 320W) for 360 hours and the yellowing index was tested according to ASTM D1925-70 (1988) standard.

[0040] Tensile properties were tested according to GB / T 1040.1-2018 standard.

[0041] Table 1 Performance of TPU-type heat insulation film

[0042] <![CDATA[Thermal conductivity (W·m -1 ·K -1 ).]]> Yellowing index (%) Tensile strength (MPa) Example 1 0.1617 25.6 12.8 Example 2 0.1525 20.3 11.9 Example 3 0.1358 16.9 9.5 Example 4 0.1224 14.5 7.3 Comparative Example 1 0.1740 33.9 10.3 Comparative Example 2 0.1689 29.2 11.4 Comparative Example 3 0.1661 30.7 10.9

[0043] After testing, compared with Comparative Example 1, the mesoporous titanium dioxide of Examples 1-4, after modification with N-benzyloxycarbonyl-3,4-dihydroxyphenylethylamine, showed improved dispersibility, which is beneficial for solving the agglomeration problem of titanium dioxide. Simultaneously, the modified titanium dioxide contained urethane groups (…). The improved compatibility with polyurethane allows it to be uniformly dispersed in the polyurethane film matrix, significantly reducing the thermal conductivity and yellowing index, and improving heat insulation and UV resistance. At the same time, the excellent compatibility between the two increases the interfacial bonding force, enabling the polyurethane film to maintain high tensile strength and excellent mechanical properties.

[0044] Compared with Example 1, Comparative Example 2 uses conventional dopamine to modify mesoporous titanium dioxide, which does not contain urethane groups and has poor compatibility with polyurethane. The interfacial bonding between the two is weak, resulting in a higher thermal conductivity and yellowing index of the polyurethane film, as well as lower tensile strength.

[0045] Compared with Example 1, Comparative Example 3 uses diphenylmethane diisocyanate to modify mesoporous titanium dioxide. Usually, after high-temperature calcination, the hydroxyl content on the surface of mesoporous titanium dioxide is low, and the reactivity with diphenylmethane diisocyanate is weak, resulting in poor modification effect on mesoporous titanium dioxide. This is not conducive to improving the dispersibility and agglomeration of titanium dioxide, resulting in a large thermal conductivity and yellowing index of polyurethane film and low tensile strength.

[0046] The foregoing description has fully disclosed the specific embodiments of this application. It should be noted that any modifications made by those skilled in the art to the specific embodiments of this application do not depart from the scope of the claims. Accordingly, the scope of the claims of this application is not limited to the foregoing specific embodiments.

Claims

1. A process for preparing a TPU type heat insulation film for a sunroof, characterized by, The preparation process comprises the following steps: (1) adding mesoporous titanium dioxide into a solvent, ultrasonic dispersion in an ultrasonic instrument, then adding N-benzyloxy carbonyl-3,4-dihydroxyphenethylamine, stirring for modification, washing after filtration, drying to obtain modified mesoporous titanium dioxide; (2) mixing polyurethane resin and modified mesoporous titanium dioxide, melt extruding through an extruder, granulating, then blowing into a film through a film blowing machine to obtain a TPU type heat insulation film for sunroof.

2. The process for preparing a TPU type thermal insulation film for a sunroof according to claim 1, characterized by, The solvent in the step (1) is an ethanol aqueous solution with a volume fraction of 50-80%.

3. The process for preparing a TPU type thermal insulation film for a sunroof according to claim 1, characterized in that, The ratio of mesoporous titanium dioxide and N-benzyloxy carbonyl-3,4-dihydroxyphenethylamine in the step (1) is 100g:(4-12)g.

4. The process for preparing a TPU type thermal insulation film for a sunroof according to claim 1, characterized in that, The ultrasonic dispersion time in the step (1) is 20-40min.

5. The process for preparing a TPU type thermal insulation film for a sunroof according to claim 1, characterized in that, The modification temperature in the step (1) is 15-30℃, and the time is 6-12h.

6. The process for preparing a TPU type thermal insulation film for a sunroof according to claim 1, characterized by, The ratio of polyurethane resin and modified mesoporous titanium dioxide in the step (2) is 100:(2-8).

7. The process for preparing a TPU type thermal insulation film for a sunroof according to claim 1, characterized by, The temperature of the 1-5 sections of the extruder in the step (2) is 140-190℃, and the screw rotation speed is 30-60r / min.

8. The process for preparing a TPU type thermal insulation film for a sunroof according to claim 1, characterized by, The temperature of the 1-3 sections of the film blowing machine in the step (2) is 160-185℃.

9. A TPU type heat insulation film for sunroof obtained by the preparation process according to any one of claims 1-8.