WO2020215245A1 - 一种屏蔽太阳能的热管理织物、其制备方法和应用 - Google Patents

一种屏蔽太阳能的热管理织物、其制备方法和应用 Download PDF

Info

Publication number
WO2020215245A1
WO2020215245A1 PCT/CN2019/084074 CN2019084074W WO2020215245A1 WO 2020215245 A1 WO2020215245 A1 WO 2020215245A1 CN 2019084074 W CN2019084074 W CN 2019084074W WO 2020215245 A1 WO2020215245 A1 WO 2020215245A1
Authority
WO
WIPO (PCT)
Prior art keywords
fabric
microrods
coating
reflective
thermal management
Prior art date
Application number
PCT/CN2019/084074
Other languages
English (en)
French (fr)
Inventor
尚颂民
赵家乐
Original Assignee
香港纺织及成衣研发中心有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 香港纺织及成衣研发中心有限公司 filed Critical 香港纺织及成衣研发中心有限公司
Priority to PCT/CN2019/084074 priority Critical patent/WO2020215245A1/zh
Publication of WO2020215245A1 publication Critical patent/WO2020215245A1/zh

Links

Images

Classifications

    • D—TEXTILES; PAPER
    • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
    • D06M—TREATMENT, NOT PROVIDED FOR ELSEWHERE IN CLASS D06, OF FIBRES, THREADS, YARNS, FABRICS, FEATHERS OR FIBROUS GOODS MADE FROM SUCH MATERIALS
    • D06M11/00—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with inorganic substances or complexes thereof; Such treatment combined with mechanical treatment, e.g. mercerising
    • D06M11/32—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with inorganic substances or complexes thereof; Such treatment combined with mechanical treatment, e.g. mercerising with oxygen, ozone, ozonides, oxides, hydroxides or percompounds; Salts derived from anions with an amphoteric element-oxygen bond
    • D06M11/36—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with inorganic substances or complexes thereof; Such treatment combined with mechanical treatment, e.g. mercerising with oxygen, ozone, ozonides, oxides, hydroxides or percompounds; Salts derived from anions with an amphoteric element-oxygen bond with oxides, hydroxides or mixed oxides; with salts derived from anions with an amphoteric element-oxygen bond
    • D06M11/44—Oxides or hydroxides of elements of Groups 2 or 12 of the Periodic Table; Zincates; Cadmates
    • D—TEXTILES; PAPER
    • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
    • D06M—TREATMENT, NOT PROVIDED FOR ELSEWHERE IN CLASS D06, OF FIBRES, THREADS, YARNS, FABRICS, FEATHERS OR FIBROUS GOODS MADE FROM SUCH MATERIALS
    • D06M11/00—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with inorganic substances or complexes thereof; Such treatment combined with mechanical treatment, e.g. mercerising
    • D06M11/32—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with inorganic substances or complexes thereof; Such treatment combined with mechanical treatment, e.g. mercerising with oxygen, ozone, ozonides, oxides, hydroxides or percompounds; Salts derived from anions with an amphoteric element-oxygen bond
    • D06M11/36—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with inorganic substances or complexes thereof; Such treatment combined with mechanical treatment, e.g. mercerising with oxygen, ozone, ozonides, oxides, hydroxides or percompounds; Salts derived from anions with an amphoteric element-oxygen bond with oxides, hydroxides or mixed oxides; with salts derived from anions with an amphoteric element-oxygen bond
    • D06M11/46—Oxides or hydroxides of elements of Groups 4 or 14 of the Periodic Table; Titanates; Zirconates; Stannates; Plumbates

Definitions

  • the invention belongs to the technical field of building thermal insulation materials, and specifically relates to a thermal management fabric for shielding solar energy, and a preparation method and application thereof.
  • the Urban Heat Island Effect (UHI) has caused various negative effects on the comfort, health, economy and environment of many cities such as Hong Kong.
  • UHI The Urban Heat Island Effect
  • existing solutions such as green roofs have been proposed.
  • high construction and maintenance costs hinder their widespread application, that is, green roofs are limited due to high cost and low cooling capacity.
  • Cool roof is an effective way to solve the heat island effect. Cool roof is a new solution due to its high solar reflectivity and heat emissivity. It can reflect most of the incident solar heat during the day and radiate the stored heat during the cool night. It can be easily constructed by applying reflective paint, sheet coverings, tiles or shingles on the roof of ordinary buildings, and its application cost is as low as US$0.75-1.50 per square foot. Various studies have proven that, especially in tropical areas like Hong Kong, a cool roof can effectively reduce the surface temperature, thereby reducing annual cooling costs. With a large area of cool roof, the reflectivity of the ground to the solar heat can be enhanced, and the heat island effect can be minimized. However, due to the limited roof area suitable for cool roofs, its effectiveness is restricted. At the same time, the use of traditional construction methods for roof construction is time-consuming and expensive.
  • Fabric roof is a way to quickly increase the roof area.
  • the fabric roof can be built in a large area, low cost and in a short time.
  • the current construction textile products have the problem of low solar shielding ability and are particularly sensitive to environmental changes, that is, the speed of impact is much faster than most other building materials, and the impact is much greater than other building materials. Therefore, the existing fabric roof still cannot be used as a cold roof unless its solar shielding ability has been greatly improved.
  • coating aluminum foil can improve the solar heat shielding ability of the fabric, which can increase the reflectivity and reduce the transmission of radiant heat.
  • this method is less used in fabric roofing.
  • First of all, it has a very shiny appearance due to directional reflection, which can cause nearby light pollution.
  • Second, it has very low translucency, which increases the demand for artificial lighting systems.
  • Third, its emissivity is very low, and it is difficult to release the stored heat through radiation.
  • the present invention provides a thermal management fabric for shielding solar energy, and its preparation method and application.
  • the thermal management fabric provided by the present invention has high solar radiation reflectivity and thermal emissivity, as well as excellent solar shielding ability, which is beneficial to Its application in cool roof building materials.
  • the present invention provides a thermal management fabric shielding solar energy, including:
  • the sticks One or more of the sticks.
  • the thermal management fabric for shielding solar energy of the present invention can be referred to simply as solar thermal insulation fabric, thermal insulation coating fabric, thermal insulation fabric and the like.
  • the composite zinc oxide microrod arrays on the fabric substrate are arranged horizontally along the coating direction, which can simulate the microhair structure of Saharan silver ants (SSAnt); these reflective microrods can not only effectively It reflects solar heat without sacrificing the translucency of polyester and other fabrics, and improves the thermal emissivity.
  • the treated fabric in the embodiment of the present invention can block solar heat and reduce the temperature of the area below the fabric.
  • the technology of the invention can improve the solar shielding ability of the fabric roof, making it a low-cost cool roof. This not only improves thermal comfort, but also reduces the cost of air conditioning. At the same time, the urban heat island effect can be minimized.
  • the solar thermal insulation fabric provided by the embodiment of the present invention includes a fabric base; the present invention uses ordinary polyester and other flexible fabrics as the base, no special fabric is needed, and the cost is low.
  • the material of the fabric substrate can be one or more of polyester, nylon, cellulose fiber (such as cotton, rayon), polypropylene, and glass fiber; the present invention preferably uses ordinary polyester fabric (PET) as Fabric base.
  • the present invention has no special restrictions on the thickness, density and weight of the fabric base and the fabric structure, etc., and commercially available commercial fabrics can be used; for example, a polyester fabric with a thickness of 0.2-0.6 mm can be used.
  • the fabric base may be a woven fabric or a non-woven fabric, but generally, knitted fabrics that are easily deformed are not used.
  • a coating containing a plurality of reflective microrods is compounded; in the coating, the reflective microrods are arranged in an array horizontally along the coating direction.
  • the "composite" described in the present invention can be coated or coated, and other embodiments can also be used to perform surface treatment on the fabric substrate.
  • the reflective micro-rod refers to a micron-level rod or micron-level fibrous material that can reflect light, and can also be referred to as a reflective micro-rod; generally, its refractive index is greater than 2.
  • the reflective microrods are one or more of zinc oxide (ZnO) microrods and potassium titanate microrods, preferably zinc oxide microrods (also called zinc oxide microcrystalline fibers).
  • the reflective micron rod has a diameter of 0.5 to 2.6 microns, preferably 0.8 to 2.6 microns, and a length of 10 to 80 microns, preferably 10 to 40 microns; specifically, the average diameter is 1 micron.
  • ZnO microrods with an average length of 40 microns or potassium titanate microrods with an average diameter of 0.5 microns and a length of 80 microns.
  • the reflective microrods are horizontally arranged in an array (aligned reflective microrod array) along the coating direction.
  • the reflective microrods inside the coating are well aligned, and their orientation distribution or alignment distribution fits the Lorentzian function well, and the half-maximum value
  • the full width (full width at half maximum) is 22.3°.
  • a layer of oriented and aligned zinc oxide microrod array is coated on the fabric substrate to simulate the micro-hair structure of SSAnt.
  • the mainstream magazine "Science” published a survey on SSAnt's new cooling mechanism, enabling it to survive in the hot desert.
  • Saharan silver ant (SSAnt) has a reflective micro-hair array, which improves the solar shielding ability through the following ways: 1) Like an optical prism array, it reflects most of the solar heat that enters the body; 2) It improves the effectiveness through radiation The thermal emissivity of the in vivo heat treatment.
  • the directional arrangement coating containing the reflective micron rod array of the present invention not only improves the reflectivity of solar radiation, but also improves the thermal emissivity, thereby significantly improving the solar shielding ability of polyester and other fabrics.
  • This method can make the construction cost of the cool roof low, and improve the thermal comfort of outdoor activities. It can solve the key problem of the current construction textile products, that is, in the hot summer, the protection against solar heat is limited.
  • the thermal insulation fabric of the present invention has excellent wear resistance, can improve the waterproofness and mechanical strength of the fabric, and also has functions such as flame retardant.
  • the coating is formed by coating a coating agent containing the reflective microrods on a fabric substrate.
  • the finishing agent contains three main components: binder, diluent and reflective micro-rod coating material.
  • the adhesive mainly bonds the fabric and the coating material, and is preferably a silicone resin adhesive (silicone adhesive) such as liquid silicone rubber.
  • the liquid silicone rubber described in the embodiment of the present invention is also called a dimethyl polysiloxane adhesive, and has excellent fire resistance, water resistance and ultraviolet resistance.
  • the dimethyl polysiloxane adhesive refers to Wacker Chemie AG's 6200 model products
  • 6200 is a platinum-catalyzed and crosslinked two-component silicone rubber coating. It is solvent-free and has good fluidity; it can be used to functionalize polydimethylsiloxane with different groups 6200A and 6200B, mixed in the same proportion, 6200A and No reaction occurs when 6200B is stored separately, and it will undergo addition cross-linking reaction when heated when mixed together to form dimethyl polysiloxane (PDMS).
  • PDMS dimethyl polysiloxane
  • the embodiment of the present invention also uses a diluent.
  • a diluent any commercial liquid silicone rubber and a diluent for liquid silicone rubber can be used.
  • Commercial diluents for liquid silicone rubber such as silicone oil, can be used to adjust the viscosity of the coating agent.
  • the present invention preferably uses silicone oil as a diluent to reduce the viscosity of liquid silicone rubber and disperse zinc oxide micro-rods; the viscosity of the silicone oil can be 10-50 cSt (the viscosity of pure silicone oil at room temperature), preferably 25-45 cSt, using Dow Corning products are fine.
  • the coating agent is also called coating agent, coating agent, filming agent, coating agent, etc., generally by mixing and stirring, etc.
  • Coating agent based on polysiloxane adhesive The embodiment of the present invention is coated to obtain a coating, and the thickness of the coating is usually between 0.03 and 0.1 mm.
  • the solar energy shielding thermal management fabric of the embodiment of the present invention has a water permeability of less than 0.2 g (AATCC test method 35-2006 (water resistance: rain test)), and has excellent water resistance.
  • the coated fabric has high UV aging resistance, cleaning resistance and abrasion resistance. Compared with uncoated fabrics, in the range of 400-800 nanometers, the reflectance of the heat-insulating coated fabrics provided by the embodiments of the present invention can be increased by 20%, has excellent solar shielding ability, and is beneficial to application.
  • an embodiment of the present invention provides a method for preparing a solar-shielding thermal management fabric, which includes the following steps:
  • the reflective micro rods are one or more of zinc oxide micro rods and potassium titanate micro rods.
  • a coating agent is used on the fabric, and a layer of aligned reflective micron rod film such as zinc oxide is coated by a blade coating method, thereby improving the solar shielding ability of the architectural fabric.
  • the finishing process can include three main steps: 1) preparing a pigment paste containing reflective microrods; 2) preparing a coating agent containing reflective microrods, adhesives, etc.; 3) laminating horizontally arranged reflective microrod films into The reflective microfilament array is coated on the surface of the fabric.
  • the embodiment of the present invention first prepares a pigment paste containing reflective micron rods.
  • the preparation process is as follows: 1-9g, preferably 2-7g, reflective micron rods can be ground and sieved after removing water, and then dispersed in a diluent such as 5-15 In one millilitre of silicone oil, a pigment paste is obtained. Specifically, a certain amount of reflective micro-rods are placed in a vacuum oven and dried at 100° C. for 1 hour to 2 hours to remove water; then they are ground and dispersed with a sieve. Add the sieved reflective micro-rods to the silicone oil under vigorous stirring, and then use an ultrasonic disperser to disperse the mixture to form a stable pigment paste.
  • the reflective micro rods are one or more of zinc oxide micro rods and potassium titanate micro rods, preferably zinc oxide micro rods.
  • the diameter of the reflective micro-rods, such as zinc oxide micro-rods, is preferably 0.5-2.6 microns, more preferably 0.8-2.6 microns, and the length is 10-80 microns, preferably 10-40 microns; the micron-level reflective material can be very good Simulate the microfilament array of SSAnt.
  • the source of the reflective micron rods there is no special restriction on the source of the reflective micron rods, and commercially available products can be used, or they can be prepared by themselves.
  • One-dimensional zinc oxide microcrystalline fibers or zinc oxide microrods are usually synthesized by chemical vapor deposition, electrodeposition, electrostatic spinning and laser-assisted flow deposition; the present invention preferably adopts low-temperature template-free hydrothermal synthesis of zinc oxide microrods , Its cost is low, and the growth of zinc oxide microrods is stable.
  • the method for low-temperature template-free hydrothermal synthesis of zinc oxide microcrystalline fibers includes the following steps:
  • Step 1 The divalent zinc salt is reacted with a strong base in water to obtain a first transparent solution containing Zn(OH) 4 2- ions; the divalent zinc salt is selected from zinc chloride, zinc acetate and zinc nitrate One or more
  • Step 2 The first transparent solution is reacted in a reactor with a non-sticky surface in the presence of a surfactant and the temperature does not exceed 100°C to obtain zinc oxide microcrystalline fibers;
  • the surfactant is selected from One or more of polyoxyethylene octyl phenyl ether with 9-10 units of dodecyl sulfate and oxyethylene.
  • the strong base can be selected from one or more of sodium hydroxide and potassium hydroxide.
  • Step 1 specifically includes: reacting 0.02-0.07 moles of divalent zinc salt with a strong base in 50-200 ml of water, and the concentration of the strong base in the water is 6-10M to obtain a Zn(OH) 4 2- ion-containing The first clear solution.
  • the surfactant is added to the reactor in the form of a surfactant aqueous solution, the concentration of the surfactant aqueous solution is 20-50 ml/500-2000 ml, and the first transparent solution is compatible with the surface active The volume ratio of the aqueous solution is 1:6-10.
  • the reaction temperature is 80-100°C. The reaction is maintained for 5 to 10 hours, and then cooled to room temperature, and then separated, washed and dried in sequence. The drying temperature is 60 to 100° C. and the time is 4 to 8 hours to obtain zinc oxide microcrystalline fibers.
  • Triton X-100 solution was prepared by dissolving 30 ml Triton X-100 in 900 ml deionized water. 118 mL of the prepared Zn(OH) 4 2- solution and 882 mL of Triton X-100 solution were mixed in a 1 L polypropylene container, and the resulting mixture was reacted at 100° C.
  • the resulting reaction solution was cooled to room temperature. Centrifuge the cooled reaction solution at a speed of 1000-5000 rpm to obtain a white precipitate. Under the action of ultrasound, the white precipitate was washed several times with deionized water and ethanol to remove unreacted chemical substances, and then centrifuged to recover. Finally, the washed white precipitate was dried in the air at 60°C for 4 hours to obtain dried zinc oxide microrods.
  • the dried reflective micron rod is ground and then sieved, and the opening size of the sieve is preferably 40-100 microns.
  • the viscosity of the silicone oil diluent may be 10-50 cSt (room temperature), preferably 25-45 cSt.
  • the finishing agent contains a binder and a diluent.
  • the binder is preferably liquid silicone rubber, and the diluent is preferably silicone oil.
  • the process of preparing the coating agent in the preferred embodiment of the present invention is as follows: the dimethyl polysiloxane adhesive can be 6200A and 6200B is mixed and prepared in equal proportion; the prepared pigment paste is mixed with the dimethyl polysiloxane binder to form a coating agent, preferably the pigment paste: dimethyl polysiloxane binder ( 6200A and The mass ratio of the mixture of the two 6200B) is 1-7:6-18, more preferably 2:10 or 7:10; finally, the coating agent can be placed in a vacuum at room temperature for 1 hour to 2 hours to remove The remaining air bubbles.
  • the embodiment of the present invention is applied to the fabric by the blade coating method, so that the array of the reflective micro-rods is arranged horizontally on the surface of the fabric along the coating direction, and is thermally cured. A thermal management fabric shielding solar energy is obtained.
  • the blade coating method is to use a Meyer rod (Meyer rod), a doctor blade or an air blade to remove excess coating; the present invention preferably uses a Meyer rod for coating.
  • the Meyer rod specifically refers to wire-wound rods or wire-wound rods with a steel wire diameter of 0.01-0.03 mm.
  • the fabric forms the fabric base described above, and its material, structural specifications, etc. are as described above.
  • polyester fabric is preferably used for the coating finishing, and the polyester fabric can be a polyester woven fabric with a thickness of 0.2-0.6 mm.
  • a high coating speed (1-10 m/min) is the key to realize the alignment of the microrod coating by providing a shear force to align the microrods.
  • the coating process of the zinc oxide microrods arranged horizontally on the fabric in some embodiments of the present invention is as follows: the prepared finishing agent is placed on the polyester fabric, and the Meyer rod is coated at a speed of 1-10m/min On the fabric: The coated fabric is preferably cured at 100-150°C for 2 minutes to 10 minutes. After the coating process, the zinc oxide microrods are aligned horizontally along the coating direction on the polyester fabric.
  • the thermally cured coated fabric can be washed with a washing machine to remove unattached zinc oxide micro-rods, and finally dried in dry air at 100-150°C for 2 minutes to 10 minutes to obtain a dry thermal management fabric shielding solar energy.
  • the present invention can reproduce the micro-hair structure of SSAnt on the surface of the fabric.
  • the invention can obtain the solar heat reflecting surface of SSAnt on the surface of the fabric, which improves the solar heat shielding ability of the coated fabric.
  • the present invention Compared with other thermal insulation fabrics, the present invention has the following advantages: a. No special fabric is required, and it can be used for fabrics such as ordinary polyester. b. It can be used with machines commonly used in the textile industry. c. Can significantly improve the solar heat shielding ability of polyester and other fabrics, and at the same time have excellent wear resistance, can improve the waterproof and mechanical strength of the fabric.
  • the present invention also provides the application of the above-mentioned solar-shielding thermal management fabric in the preparation of building materials.
  • fabrics such as polyester are made into solar thermal reflective fabrics, which can solve the key problem of limited summer solar thermal protection capabilities of current architectural textile products.
  • the fabric treated by the invention can block solar heat and reduce the temperature of the area under the fabric. This technology can improve the solar shielding ability of the fabric roof, making it a low-cost cool roof. This not only improves thermal comfort, but also reduces the cost of air conditioning. At the same time, the urban heat island effect can be minimized.
  • Figure 1 is a scanning electron microscope image of the zinc oxide microrods prepared in Example 1 under 10 microns;
  • Figure 2 is a scanning electron microscope image of the zinc oxide microrods prepared in Example 1 under 20 microns;
  • Figure 3 is a scanning electron microscope image of the surface of the zinc oxide microrod coated fabric prepared in Example 2;
  • Example 4 is a scanning electron microscope image of a cross-section of the zinc oxide microrod coated fabric prepared in Example 2;
  • Figure 5 is an optical micrograph of the surface of the zinc oxide microrod coated fabric prepared in Example 2.
  • Example 6 is a diagram showing the orientation distribution of microrods on the surface of the zinc oxide microrod coated fabric prepared in Example 2;
  • Figure 7 is the UV/Visible spectrum of the zinc oxide microrod coated fabric and the original polyester fabric prepared in Example 2;
  • Figure 8 is a comparison of the surface temperature of the black foam measured within 1 hour between the zinc oxide microrod coated fabric prepared in Example 2 and different samples;
  • Figure 9 is a comparison of the surface temperature of the black foam measured within 1 hour between the potassium titanate microrod coated fabric prepared in Example 3 and different samples;
  • Figure 10 is a comparison of the surface temperature of the black foam measured within 1 hour of different coated fabric samples prepared in Example 4.
  • Figure 11 is a photo comparison diagram of the coated fabric sample prepared in Example 2 before and after the accelerated cleaning process
  • Figure 12 is the UV/Vis spectrum images of the coated fabric sample prepared in Example 2 for different times of accelerated cleaning
  • Figure 13 is a photo comparison diagram of the coated fabric prepared in Example 2 before and after the solar weathering test
  • Figure 14 is the UV/Vis spectrum images of the coated fabric sample prepared in Example 2 during the solar weathering test at different times;
  • Figure 15 is a photo comparison diagram of the coated polyester fabric prepared in Example 2 after different wear.
  • thermal management fabric for shielding solar energy provided by the present invention, its preparation method and application will be specifically described below in conjunction with examples.
  • Triton X-100 solution was prepared by dissolving 30 ml Triton X-100 in 900 ml deionized water. 118 mL of the prepared Zn(OH) 4 2- solution and 882 mL of Triton X-100 solution were mixed in a 1 L polypropylene container, and the resulting mixture was reacted at 100° C.
  • the resulting reaction solution was cooled to room temperature. Centrifuge the cooled reaction solution at a speed of 5000 rpm to obtain a white precipitate. Under the action of ultrasound, the white precipitate was washed several times with deionized water and ethanol to remove unreacted chemical substances, and then centrifuged to recover. Finally, the washed white precipitate was dried in the air at 60°C for 4 hours to obtain dried zinc oxide microrods.
  • the scanning electron microscope (SEM) images of the prepared zinc oxide microrods are shown in Figure 1 and Figure 2, which clearly shows that the resulting sample is rod-shaped.
  • the zinc oxide microrods have a diameter of about 0.8-2.6 microns and a length of about 10-40 microns.
  • the ZnO microrods (prepared in Example 1) with a diameter of 1 ⁇ m and a length of 40 ⁇ m were placed in a vacuum oven and dried at 100° C. for 1 hour to remove water. Then it was ground and dispersed with a sieve with a pore size of 40 microns. Mix 5 g of the sieved zinc oxide micro-rods with 7 mL of silicone oil (Dow Corning, room temperature viscosity 25 cST) through vigorous stirring; use an ultrasonic disperser to disperse the mixture to form a stable pigment paste.
  • silicone oil Dow Corning, room temperature viscosity 25 cST
  • 6200A and LR 6200B is formulated into dimethyl polysiloxane adhesive in the same proportion. Then mix the above-mentioned pigment paste with 10g of dimethyl polysiloxane binder to make the pigment paste and dimethyl polysiloxane binder ( 6200A and The mass ratio of 6200B is 2:10. The coating agent obtained by mixing is finally placed in a vacuum for 1 hour to remove the trapped air bubbles at room temperature. The prepared coating agent is stored at room temperature and can be stored for 5 days before use.
  • the prepared coating agent was placed on a polyester woven fabric with a thickness of 0.5 mm, and a Meyer rod with a wire diameter of 0.01 mm was used for coating on the fabric at a speed of 3 m/min.
  • the coated fabric was cured at 100°C for 10 minutes.
  • the coated fabric after heat curing is washed with a washing machine to remove unattached zinc oxide micro-rods.
  • the washed fabric is dried in dry air at 100°C for 2-10 minutes to obtain a dried coated fabric.
  • the coating thickness is 0.0542mm.
  • the scanning electron microscope image of the obtained coated fabric is shown in FIG. 3, the scanning electron microscope image of the cross-section of the coated fabric is shown in FIG. 4, and its optical microscopic image is shown in FIG.
  • the results show that the coating surface of the coated fabric is smooth, and the zinc oxide microrods are arranged neatly, and it is found that the microrods in the coating are arranged horizontally along the coating direction.
  • OrientationJ was used to study the orientation distribution of microrods inside the coating, and the results are shown in Figure 6.
  • the results show that the microrod alignment distribution can fit the Lorentz function well; the full width at the half maximum is 22.3°, which means that the microrods are well aligned in the coating.
  • a solar simulator irradiated by AM1.5G is used as a light source; a plastic box is used to prevent temperature fluctuations caused by air convection. Place the black foam at the bottom of the plastic box to absorb unobstructed sunlight, making the temperature of the black foam an indicator of the fabric's sun-shading ability. The fabric samples are placed on top of the plastic box to block sunlight. Four thermocouples are fed into the box and contact the bottom to measure the temperature inside the casing.
  • polyester woven fabric T-PET
  • silicone rubber coated fabric the original fabric is coated with a layer of the aforementioned binder PDMS without other additions
  • glass sheets glass with a thickness of 3 mm
  • coated micro-rod polyester fabric T-ZM
  • original polyester fabric T-PET
  • silicone rubber coated polyester fabric T-PDMS
  • glass sheet Glass
  • the ground temperature is 54.9°C, 64.8°C, 64.7°C and 107.8°C respectively.
  • the ground temperature of the PET fabric coated with zinc oxide microrods is 10°C lower than that of the PET fabric and silicone rubber coated PET fabric, and 53°C lower than that of the glass flakes.
  • Potassium titanate microrods (purity 99.5%, brand: Zirconium Tin Nano Company) with a diameter of 0.5 microns and a length of 80 microns were placed in a vacuum oven and dried at 100° C. for 1 hour to remove moisture. Then it was ground and dispersed with a sieve with a pore size of 40 microns. 0-9g sieved potassium titanate microrods are stirred vigorously and mixed into 7mL silicone oil (Dow Corning, room temperature viscosity 25cST); the mixture is dispersed with an ultrasonic disperser to form a stable pigment paste.
  • 7mL silicone oil Dow Corning, room temperature viscosity 25cST
  • 6200A and LR 6200B is formulated into dimethyl polysiloxane adhesive in the same proportion. Then mix the above pigment paste with 10 grams of dimethyl polysiloxane binder to make the pigment paste and dimethyl polysiloxane binder ( 6200A and The mass ratio of 6200B is 7:10. The coating agent obtained by mixing is finally placed in a vacuum for 1 hour to remove the trapped air bubbles at room temperature. The prepared coating agent is stored at room temperature and can be stored for 5 days before use.
  • the prepared coating agent was placed on a polypropylene woven fabric with a thickness of 0.3 mm, and a Meyer rod with a wire diameter of 0.01 mm was used for coating on the fabric at a speed of 3 m/min.
  • the coated fabric was cured at 100°C for 10 minutes.
  • the coated fabric after heat curing is washed with a washing machine to remove unattached micro-rods.
  • the washed fabric is dried in dry air at 100°C for 2-10 minutes to obtain a dried coated fabric.
  • the coating thickness is 0.1mm.
  • Example 2 original polypropylene fabric (pp0) and polypropylene fabric coated with 0g, 2.25g, 4.5g and 9g microrods (abbreviated as pp+pdms, pp2.25, pp4.5, pp9) ,
  • the ground temperature after 1h irradiation was 65°C, 60°C, 55°C, 45°C and 42°C, as shown in Figure 9.
  • the ZnO microrods (prepared in Example 1) with a diameter of 1 ⁇ m and a length of 40 ⁇ m were placed in a vacuum oven and dried at 100° C. for 1 hour to remove water. It was then ground and dispersed with a sieve with a pore size of 40 microns. Mix 0-9 g of the sieved zinc oxide microrods with 7 mL of silicone oil (Dow Corning, room temperature viscosity 25 cST) through vigorous stirring; disperse the mixture with an ultrasonic disperser to form a stable pigment paste.
  • silicone oil Dow Corning, room temperature viscosity 25 cST
  • 6200A and LR 6200B is formulated into dimethyl polysiloxane adhesive in the same proportion. Then mix the above-mentioned pigment paste with 10g of dimethyl polysiloxane binder to make the pigment paste and dimethyl polysiloxane binder ( 6200A and The mass ratio of 6200B is 7:10. The coating agent obtained by mixing is finally placed in a vacuum for 1 hour to remove the trapped air bubbles at room temperature. The prepared coating agent is stored at room temperature and can be stored for 5 days before use.
  • the prepared coating agent was placed on a polyester woven fabric with a thickness of 0.5 mm, and a Meyer rod with a wire diameter of 0.01 mm was used for coating on the fabric at a speed of 3 m/min.
  • the coated fabric was cured at 100°C for 10 minutes.
  • the coated fabric after heat curing is washed with a washing machine to remove unattached zinc oxide micro-rods.
  • the washed fabric is dried in dry air at 100°C for 2-10 minutes to obtain a dried coated fabric.
  • the coating thickness is 0.1mm.
  • Example 2 The coated fabric in Example 2 was subjected to the following performance tests:
  • the water resistance of the sample was tested by AATCC test method 35-2006 (water resistance: rain test). In order to simulate the torrential rain, a 5-minute test was carried out under 3 feet of water pressure. The results show that the water permeability of the coated fabric is less than 0.2g. This shows that the waterproofness of the coated fabric of the present application is significantly better than the raincoat standard of the US Customs (transmission for 2 minutes under a water pressure of 2 feet, water permeability ⁇ 1.0g).
  • the cleaning resistance of the sample was tested by AATCC 61-2006; the color change of the fabric sample after washing was evaluated in gray (AATCC EP1-2012); the fabric sample was washed by ultraviolet-visible-near infrared spectroscopy The optical performance of the fabric was evaluated; Leica stereo microscope was used to evaluate the microscopic appearance of the fabric after washing.
  • Figure 11 shows the photos of 12 samples before and after the accelerated cleaning process. The top is the sample before the accelerated cleaning, and the bottom is the sample after the accelerated cleaning. The results showed that there was no obvious change in appearance after 12 times of accelerated cleaning. Table 1 shows the gray value of the color change, and the sample after 12 times of accelerated cleaning has got a grade of 5.
  • the coated fabric sample of the present invention has high cleaning resistance, can withstand 12 rapid cleanings, and meets the delivery requirements.
  • Figure 13 shows a photo of the PET fabric coated with microrods after 1440 hours, the top is the sample weathered by sunlight for 0 hours, and the bottom is the sample weathered by sunlight for 1440 hours.
  • Table 2 shows the gray value of the color change. After the 1440h sunshine weathering test, the sample got a grade of 5 points.
  • the UV/VIS spectrum of the PET fabric coated with microrods is shown in Figure 14.
  • the spectrum of the coated sample after irradiation is similar to the fabric before the weathering test.
  • its transmittance in the visible and near-infrared bands decreased after the solar weathering test, indicating that ultraviolet radiation increased its solar reflectance. Both are not subject to UV degradation.
  • the results show that the coated fabric sample of the present invention has high anti-ultraviolet aging ability, can withstand 55-56 consecutive solar weathering, and meets the deliverable requirements.
  • a Martindale tester was used to test the abrasion resistance of the coated fabric; the color change of the tested fabric sample was evaluated in gray (AATCC EP1-2012).
  • Figure 15 is a photo of the coated polyester fabric after different abrasions. The left is the sample with 0 abrasion, the middle is the sample after 10,000 abrasion, and the right is the sample after 30,000 abrasion. The results showed that after 10,000 wear cycles, only part of the coating was removed. After 30,000 wear cycles, the surface coating is removed, but the coating between the yarns still exists. In addition, no pilling and damage to the fabric were observed. According to the gray value of the color change, the value after 30k cycles is 3-4, indicating that the coating in the present invention has high wear resistance.
  • the composite zinc oxide microrod array on the fabric substrate is arranged horizontally along the coating direction, which can simulate the micro-hair structure of Saharan silver ants (SSAnt); these reflections Micron rods can not only reflect solar heat effectively without sacrificing the translucency of polyester and other fabrics, but also increase the thermal emissivity.
  • the treated fabric in the embodiment of the present invention can block solar heat and reduce the temperature of the area below the fabric.
  • the technology of the invention can improve the solar shielding ability of the fabric roof, making it a low-cost cool roof. This not only improves thermal comfort, but also reduces the cost of air conditioning. At the same time, the urban heat island effect can be minimized.

Landscapes

  • Engineering & Computer Science (AREA)
  • Textile Engineering (AREA)
  • Laminated Bodies (AREA)

Abstract

一种屏蔽太阳能的热管理织物、其制备方法和应用，该热管理织物包括：织物基底；复合在所述织物基底表面的含若干反光微米棒的涂层，所述涂层中反光微米棒呈沿涂层方向水平排列的阵列；所述反光微米棒为氧化锌微棒和钛酸钾微棒中的一种或多种。实施例织物基底上复合的氧化锌微棒阵列沿涂层方向水平排列，可模拟SSAnt；这些反光微米棒不仅可以有效地反射太阳热量且不牺牲聚酯等织物的半透明性，并提高了热发射率。经处理后的织物可以遮挡太阳热量，降低该织物下方区域的温度。可提高织物屋顶的太阳能屏蔽能力，使其成为低成本的凉爽屋顶。这不仅提高了热舒适性，而且降低了空调的费用，还可以最大限度地减小热岛效应。

Description

一种屏蔽太阳能的热管理织物、其制备方法和应用 技术领域
本发明属于建筑隔热材料技术领域，具体涉及一种屏蔽太阳能的热管理织物、其制备方法和应用。
背景技术
城市热岛效应(UHI)对香港等许多城市的舒适、健康、经济和环境造成了各种负面影响。为了减少热岛效应，提高热舒适性，提出了绿色屋顶(green roof)等现有解决方案。然而，高的建设和维护成本阻碍了它们的广泛应用，即绿色屋顶因成本高和冷却能力低而受限。
凉爽屋顶(Cool roof)是解决热岛效应的有效途径，凉爽屋顶由于具有较高的太阳反射率和热发射率，是一种新的解决方案。它可以在白天反射大部分入射的太阳热量，并在凉爽的夜间将储存的热量辐射出去。它可以很容易地通过在普通的建筑屋顶上涂上反光漆、薄板覆盖物、瓷砖或木瓦来建造，其应用成本低至每平方英尺0.75-1.50美元。各种研究已经证明，特别是在像香港这样的热带地区，凉爽屋顶(Cool roof)可以有效地降低表面温度，从而降低每年的制冷费用。通过大面积的凉爽屋顶(Cool roof)，可增强地面对太阳热能的反射率，并且使热岛效应最小化。然而，由于适用于凉爽屋顶的屋顶面积有限，其有效性受到制约。同时，采用传统的建筑方法进行屋顶施工，既费时又昂贵。
织物屋顶(fabric roof)是一种快速增加屋顶面积的方法，织物屋顶可以大面积、低成本和在短的时间内建造。然而，目前的建筑纺织产品存在太阳能屏蔽能力低的问题，并且对环境变化尤其敏感，即受影响的速度比其他大多数建筑材料快得多，也比其他建筑材料受的影响要大得多。因此，现有的织物屋顶仍不能作为冷屋顶使用，除非它的太阳能屏蔽能力有了很大的提高。
目前，涂覆铝箔可以提高织物的太阳热屏蔽能力，这样可以提高反射率，减少辐射热的传输。然而，由于多种原因，这种方法在织物屋顶中应用较少。首先，由于定向反射，它有非常闪亮的外观，会引起附近的光污染。其次，它 具有很低的半透明性，增加了对人工照明系统的需求。最后，它发射率很低，难以通过辐射释放储存的热量。
因此，为了开发出一种具有良好的太阳能屏蔽能力的织物屋顶，实现低成本凉爽屋顶的应用，提高其太阳辐射反射率和热发射率是非常必要的。
发明内容
有鉴于此，本发明提供一种屏蔽太阳能的热管理织物、其制备方法和应用，本发明提供的热管理织物具有较高的太阳辐射反射率和热发射率，以及优良的太阳能屏蔽能力，利于其在凉爽屋顶建筑材料中的应用。
本发明提供一种屏蔽太阳能的热管理织物，包括：
织物基底；
复合在所述织物基底表面的含若干反光微米棒的涂层，所述涂层中反光微米棒呈沿涂层方向水平排列的阵列；所述反光微米棒为氧化锌微棒和钛酸钾微棒中的一种或多种。
本发明所述屏蔽太阳能的热管理织物可简称为太阳能隔热织物、隔热涂层织物、隔热织物等。本发明实施例提供的太阳能隔热织物中，织物基底上复合的氧化锌微米棒阵列沿涂层方向水平排列，可模拟撒哈拉银蚁的微毛结构(SSAnt)；这些反光微米棒不仅可以有效地反射太阳热量而且不牺牲聚酯等织物的半透明性，并提高了热发射率。本发明实施例中经处理后的织物可以遮挡太阳热量，降低该织物下方区域的温度。本发明该技术可提高织物屋顶的太阳能屏蔽能力，使其成为低成本的凉爽屋顶。这不仅提高了热舒适性，而且降低了空调的费用。同时，可以最大限度地减小城市热岛效应。
本发明实施例提供的太阳能隔热织物包括织物基底；本发明以普通的聚酯等柔性织物为基底，不需要特殊织物，成本较低。所述织物基底的材质可为聚酯、尼龙、纤维素纤维(如棉、人造丝)、聚丙烯和玻璃纤维等中的一种或多种；本发明优选采用普通的涤纶织物(PET)为织物基底。
本发明对所述织物基底的厚度、密度和重量以及织物组织结构等没有特殊限制，采用市售的商用织物即可；例如，可采用厚度为0.2～0.6mm的聚酯织物。在本发明的实施例中，所述织物基底可为机织织物或非织造布，但通常不 采用容易变形的针织物。
在本发明所述织物基底表面，复合有包含若干反光微米棒的涂层；所述涂层中反光微米棒呈沿涂层方向水平排列的阵列。本发明所述的“复合”可以是涂覆、涂布的方式，也可以采用其他实施方式对织物基底进行表面处理。所述的反光微米棒是指能反射光的微米级棒状或微米级纤维状材料，也可简称反光微棒；一般地，其折射率大于2。在本发明中，所述反光微米棒为氧化锌(ZnO)微棒和钛酸钾微棒中的一种或多种，优选为氧化锌微棒(也可称为氧化锌微晶纤维)。在本发明的实施例中，所述反光微米棒的直径为0.5～2.6微米、优选为0.8～2.6微米，长度为10～80微米、优选为10～40微米；具体例如，平均直径为1微米、平均长度为40微米的ZnO微棒，或者，平均直径为0.5微米、长度为80微米的钛酸钾微棒。
在本发明所述涂层中，所述反光微米棒沿涂层方向水平排列成阵列(aligned reflective microrod array)。在本发明的实施例中，根据OrientationJ，所述涂层内部反光微米棒很好地对齐，其取向分布或者对齐分布很好地拟合洛伦兹函数(Lorentzian function)，半极大值处的全宽度(full width at half maximum)为22.3°。
本发明实施例在织物基底上涂上一层定向对齐的氧化锌微棒阵列，模拟SSAnt的微毛结构(micro-hair structure)。2015年，主流杂志《科学》发表了一份关于SSAnt新型冷却机制的调查，使其能够在炎热的沙漠中生存。Saharan silver ant(SSAnt)有一个反射式微型毛发阵列，它通过以下方式提高了太阳能屏蔽能力：1)像一个光学棱镜阵列一样，将大部分进入体内的太阳能热反射出去；2)通过辐射提高有效的体内热处理的热发射率。
本发明含反光微米棒阵列定向排列的涂层不仅提高了太阳辐射的反射率，而且提高了热发射率，从而能显著提高涤纶等织物的太阳能屏蔽能力。这种方法可以使凉爽屋顶的建设成本低，并提高室外活动的热舒适性，可解决当前建筑纺织产品的关键问题，即在炎热的夏季，对太阳热的防护能力有限。同时，本发明所述的隔热织物具有优异的耐磨性，能提高织物的防水性和机械强度，还具有阻燃等功能。
在本发明的具体实施例中，所述涂层由含所述反光微米棒的涂饰剂在织物 基底上涂布形成。其中，所述涂饰剂包含三个主要成分：粘结剂、稀释剂和反光微米棒涂层材料。所述粘结剂主要使织物与涂层材料粘合，优选为液体硅橡胶等硅树脂粘结剂(硅酮粘结剂)。本发明实施例所述的液体硅橡胶也称为二甲基聚硅氧烷粘结剂，具有优异的耐火性、防水性和抗紫外线性。液体硅橡胶只有两种：铂固化液态硅橡胶和锡固化液态硅橡胶，这两种都可以应用于本发明。具体地，所述的二甲基聚硅氧烷粘结剂是指瓦克化学公司(Wacker Chemie AG)的
Figure PCTCN2019084074-appb-000001
6200型号的产品，
Figure PCTCN2019084074-appb-000002
6200是铂催化加成交联双组分硅橡胶涂料，并且无溶剂，流动性好；可将带有不同基团功能化的聚二甲硅氧烷
Figure PCTCN2019084074-appb-000003
6200A和
Figure PCTCN2019084074-appb-000004
6200B，以相同比例混合使用，
Figure PCTCN2019084074-appb-000005
6200A和
Figure PCTCN2019084074-appb-000006
6200B分别存放时不发生任何反应，混合在一起时加热即发生加成交联反应成为二甲基聚硅氧烷(PDMS)。
本发明实施例还使用稀释剂，具体地，任何商用液体硅橡胶和用于液体硅橡胶的稀释剂都可以使用。用于液体硅橡胶的商用稀释剂，例如硅油，可用来调节涂布剂的粘度。本发明优选以硅油作为稀释剂，降低液体硅橡胶的粘度，分散氧化锌微棒；所述硅油的粘度可为10～50cSt(室温下单纯硅油的粘度)，优选为25～45cSt，采用陶氏康宁产品即可。
在本发明的实施例中，所述涂饰剂(coating agent)也称为涂布剂、涂层剂、涂膜剂、涂料剂等，一般通过混合搅拌等方式，制备含反光微米棒和二甲基聚硅氧烷粘结剂的涂布剂。本发明实施例涂布得到涂层，涂层厚度通常在0.03～0.1mm之间。本发明实施例所述屏蔽太阳能的热管理织物的透水量小于0.2g(AATCC试验方法35-2006(耐水性：雨水试验))，防水性优异。并且，该涂层织物具有很高的抗紫外线老化能力、耐清洗性和耐磨性。相比未涂层织物，在400-800纳米范围内，本发明实施例提供的隔热涂层织物的反射率能增加20％，具有优异的太阳能屏蔽能力，利于应用。
相应地，本发明实施例提供一种屏蔽太阳能的热管理织物的制备方法，包括以下步骤：
将含反光微米棒的涂饰剂通过刀片涂覆法在织物上涂布，使所述反光微米棒的阵列沿涂布方向水平排列在织物表面，经过热固化，得到屏蔽太阳能的热管理织物；所述反光微米棒为氧化锌微棒和钛酸钾微棒中的一种或多种。
本发明方法通过在织物上使用涂饰剂，利用刀片涂覆法涂上一层对齐的氧化锌等反光微米棒膜，从而提高建筑织物的太阳能屏蔽能力。该整理过程可包括三个主要步骤：1)制备含反光微米棒的颜料糊；2)制备含反光微米棒、粘结剂等的涂饰剂；3)将水平排列的反光微米棒膜层压成反射性微丝阵列涂布在织物表面。
本发明实施例首先制备含反光微米棒的颜料糊，其制备工艺如下：可将1～9g、优选2-7g的反光微米棒除水后研磨、过筛，再分散于稀释剂如5-15毫升硅油中，得到颜料糊。具体地，将一定量的反光微棒置于真空烘箱中，在100℃干燥1小时-2小时，以除去水分；然后研磨，用筛子分散。将过筛的反光微棒在剧烈搅拌的条件下加入硅油中，然后用超声波分散器分散混合物，形成稳定的颜料糊(pigment paste)。
其中，所述的反光微米棒为氧化锌微棒和钛酸钾微棒中的一种或多种，优选为氧化锌微棒。所述反光微米棒如氧化锌微棒的直径优选为0.5～2.6微米，更优选0.8-2.6微米，且长度为10～80微米，优选为10-40微米；该微米级反光材料能很好地模拟SSAnt的微丝阵列。
本发明对所述反光微米棒的来源没有特殊限制，可以采用市售产品，也可以自行制备得到。一维氧化锌微晶纤维或氧化锌微棒通常是通过化学气相沉积、电沉积、静电纺丝和激光辅助流动沉积来合成的；本发明优选采用低温无模板水热法合成的氧化锌微棒，其成本较低，氧化锌微棒生长稳定。本发明优选实施例中，氧化锌微晶纤维低温无模板水热合成的方法包括以下步骤：
步骤1、将二价锌盐与强碱在水中反应，得到含Zn(OH) 4 2-离子的第一透明溶液；所述二价锌盐选自氯化锌、醋酸锌和硝酸锌中的一种或多种；
步骤2、将所述第一透明溶液在非粘性表面的反应器中，在表面活性剂存在且温度不超过100℃的条件下进行反应，得到氧化锌微晶纤维；所述表面活性剂选自十二烷基硫酸盐和氧乙烯基单元为9～10个的聚氧乙烯辛基苯基醚中的一种或多种。
上述的步骤1中，所述强碱可选自氢氧化钠和氢氧化钾中的一种或多种。步骤1具体为：将0.02～0.07摩尔的二价锌盐与强碱在50～200毫升水中反应，所述强碱在水中的浓度为6～10M，得到含Zn(OH) 4 2-离子的第一透明溶液。上 述的步骤2中，所述表面活性剂以表面活性剂水溶液的形式加入反应器，所述表面活性剂水溶液的浓度为20～50毫升/500～2000毫升，所述第一透明溶液与表面活性剂水溶液的体积比为1：6～10。步骤2中，所述反应的温度为80～100℃。所述反应保持5小时～10小时，然后冷却至室温，再依次经分离、洗涤和干燥，所述干燥的温度为60～100℃，时间为4小时～8小时，得到氧化锌微晶纤维。
在典型的合成中，将0.037摩尔氯化锌(II)溶解在100毫升去离子水中，浓度为0.371M，然后在不断搅拌下添加氢氧化钠(NaOH)，直到达到8M的浓度，生成透明的Zn(OH) 4 2-溶液。Triton X-100溶液是通过将30毫升Triton X-100溶解在900毫升去离子水中制备的。将118mL制备的Zn(OH) 4 2-溶液和882mL Triton X-100溶液混合在1L聚丙烯容器中，将所得混合物在100℃下反应保持5小时，然后所得反应液冷却至室温。以1000-5000转/分的速度，将冷却的反应液离心，得到白色沉淀。在超声波作用下，用去离子水和乙醇清洗该白色沉淀数次，去除未反应的化学物质，然后离心回收。最后，将洗涤后的白色沉淀在60℃的空气中干燥4小时，获得干燥的氧化锌微棒。
在本发明的具体实施例中，所述干燥的反光微米棒研磨后过筛，筛子的开口尺寸优选为40-100微米。此外，所述硅油稀释剂的粘度可为10-50cSt(室温)，优选为25～45cSt。
除了反光微米棒材料，所述涂饰剂包含粘结剂和稀释剂。如前所述，所述粘结剂优选为液体硅橡胶，所述稀释剂优选为硅油。本发明优选实施例制备涂饰剂的工艺如下：二甲基聚硅氧烷粘结剂可通过将
Figure PCTCN2019084074-appb-000007
6200A和
Figure PCTCN2019084074-appb-000008
6200B等比例混合制备；将制得的颜料糊与所述二甲基聚硅氧烷粘结剂混合形成涂饰剂，优选使颜料糊：二甲基聚硅氧烷粘结剂(
Figure PCTCN2019084074-appb-000009
6200A和
Figure PCTCN2019084074-appb-000010
6200B两者的混合物)的质量比为1-7：6-18，更优选为2：10或7：10；最后，可在室温下将涂饰剂置于真空中1小时-2小时，以去除残留的气泡。
得到含反光微米棒等成分的涂饰剂后，本发明实施例通过刀片涂覆法在织物上进行涂布，使所述反光微米棒的阵列沿涂布方向水平排列在织物表面，经过热固化，得到屏蔽太阳能的热管理织物。
其中，所述刀片涂覆法即用梅耶棒(Meyer棒，迈尔杆)、医生刀片或空 气刀片去除多余的涂层；本发明优选采用Meyer棒进行涂布。所述Meyer棒具体是指钢丝直径为0.01-0.03mm的线绕棒或绕丝杆(wire-wound rods)。所述织物即形成上文所述的织物基底，其材质、结构规格等如前所述。本发明优选采用聚酯织物进行该涂层整理，所述聚酯织物可采用厚度为0.2-0.6mm的聚酯机织物。在本发明的实施例中，高涂布速度(1-10m/min)是通过提供剪切力使微棒对齐来实现对齐微棒涂层的关键。
具体地，本发明一些实施例中织物上水平排列的氧化锌微棒的涂层工艺如下：将制备的涂饰剂放置在聚酯织物上，以1-10m/min的速度用迈尔杆涂覆在织物上；涂覆后的织物优选在100-150℃下固化2分钟-10分钟，在该涂层工艺后，氧化锌微棒在聚酯织物上沿涂层方向水平对齐。经热固化的涂层织物可用洗衣机清洗，去除未附着的氧化锌微棒，最后在100-150℃的干燥空气中干燥2分钟-10分钟，得到干燥的屏蔽太阳能的热管理织物。通过这种方法，本发明可以在织物表面再现SSAnt的微毛发结构。本发明在织物表面可获得SSAnt的太阳热反射面，提高了涂层织物的太阳热屏蔽能力。
与其他隔热织物相比，本发明具有以下优点：a.不需要特殊织物，可用于普通涤纶等织物。b.可与纺织行业常用的机器配套使用。c.能显著提高涤纶等织物的太阳热屏蔽能力，同时具有优异的耐磨性，能提高织物的防水性和机械强度等。
此外，本发明还提供了上文所述的屏蔽太阳能的热管理织物在制备建筑材料中的应用。本发明实施例将涤纶等织物制成太阳能热反射织物，可解决当前建筑纺织产品的夏季太阳热防护能力有限的关键问题。经本发明处理后的织物可以遮挡太阳热量，降低织物下方区域的温度。该技术可提高织物屋顶的太阳能屏蔽能力，使其成为低成本的凉爽屋顶。这不仅提高了热舒适性，而且降低了空调的费用。同时，可以最大限度地减小城市热岛效应。
附图说明
图1为实施例1制备的氧化锌微棒10微米下的扫描电镜图像；
图2为实施例1制备的氧化锌微棒20微米下的扫描电镜图像；
图3为实施例2制备的氧化锌微棒涂层织物表面的扫描电镜图像；
图4为实施例2制备的氧化锌微棒涂层织物横截面的扫描电镜图像；
图5为实施例2制备的氧化锌微棒涂层织物表面的光学显微图像；
图6为实施例2制备的氧化锌微棒涂层织物表面微棒的取向分布图；
图7为实施例2制备的氧化锌微棒涂层织物和原聚酯织物的紫外/可见光谱图；
图8为实施例2制备的氧化锌微棒涂层织物与不同样品在1h内测量的黑泡沫表面温度的比较；
图9为实施例3制备的钛酸钾微棒涂层织物与不同样品在1h内测量的黑泡沫表面温度的比较；
图10为实施例4制备的不同涂层织物样品在1h内测量的黑泡沫表面温度的比较；
图11为实施例2制备的涂层织物样品加速清洗过程前后的照片对比图；
图12为实施例2制备的涂层织物样品加速清洗不同次数的紫外/可见光谱图像；
图13为实施例2制备的涂层织物日光风化试验前后的照片对比图；
图14为实施例2制备的涂层织物样品日光风化试验不同时间的紫外/可见光谱图像；
图15为实施例2制备的涂层涤纶织物在不同磨损后的照片对比图。
具体实施方式
下面对本发明实施例中的技术方案进行清楚、完整地描述，显然，所描述的实施例仅仅是本发明一部分实施例，而不是全部的实施例。基于本发明中的实施例，本领域普通技术人员在没有做出创造性劳动前提下所获得的所有其他实施例，都属于本发明保护的范围。
为了进一步理解本申请，下面结合实施例对本发明提供的一种屏蔽太阳能的热管理织物、其制备方法和应用进行具体地描述。
实施例1
在典型的合成中，将0.037摩尔氯化锌(II)溶解在100毫升去离子水中，浓度为0.371M，然后在不断搅拌下添加氢氧化钠(NaOH)，直到达到8M的浓 度，生成透明的Zn(OH) 4 2-溶液。Triton X-100溶液是通过将30毫升Triton X-100溶解在900毫升去离子水中制备的。将118mL制备的Zn(OH) 4 2-溶液和882mL Triton X-100溶液混合在1L聚丙烯容器中，将所得混合物在100℃下反应保持5小时，然后所得反应液冷却至室温。以5000转/分的速度，将冷却的反应液离心，得到白色沉淀。在超声波作用下，用去离子水和乙醇清洗该白色沉淀数次，去除未反应的化学物质，然后离心回收。最后，将洗涤后的白色沉淀在60℃的空气中干燥4小时，获得干燥的氧化锌微棒。
制备的氧化锌微棒的扫描电镜(SEM)图像如图1、图2所示，它清楚地表明所得的样品是棒状的。所述氧化锌微棒的直径约为0.8-2.6微米，长度约为10-40微米。
实施例2
将直径为1微米、长度为40微米的ZnO微棒(实施例1制得)置于真空烘箱中，在100℃下干燥1h，去除水分。然后研磨，用孔径为40微米的筛子分散。将5g过筛的氧化锌微棒通过强力搅拌，混入7mL硅油(陶氏康宁，室温粘度为25cST)中；用超声波分散器将该混合物分散，形成稳定的颜料糊。
将
Figure PCTCN2019084074-appb-000011
6200A和
Figure PCTCN2019084074-appb-000012
LR 6200B，按同等比例配制成二甲基聚硅氧烷粘结剂。然后将上述颜料糊与10g二甲基聚硅氧烷粘结剂混合，使颜料糊与二甲基聚硅氧烷粘结剂(
Figure PCTCN2019084074-appb-000013
6200A和
Figure PCTCN2019084074-appb-000014
6200B两者的混合物)的质量比为2：10。将混合得到的涂层剂最终在真空中放置1小时，在室温下去除所捕获的气泡。所制备的涂布剂存放于室温下，可在使用前贮存5天。
将制备的涂布剂放置在厚度为0.5mm的涤纶机织物上，在该织物上以丝径0.01mm的梅耶棒，速度为3m/min进行涂布。涂布后的织物在100℃下固化10min。热固化后的涂层织物用洗衣机清洗，去除未附着的氧化锌微棒。清洗后的织物在100℃的干燥空气中干燥2-10分钟，得到干燥的涂层织物。
在压缩力为6g时，涂层织物的平均厚度为0.557mm，标准差为0.0151mm，而未涂覆织物的厚度为0.5mm，则涂层厚度为0.0542mm。
所得涂层织物的扫描电镜图像如图3所示，该涂层织物的横截面的扫描电镜图像如图4所示，它的光学显微图像如图5所示。结果表明，该涂层织物的 涂层表面光滑，氧化锌微棒排列整齐，并发现在涂层中微棒沿涂层方向水平排列。利用OrientationJ研究了涂层内部微棒的取向分布，结果如图6所示。结果显示，微棒对齐分布可以很好地拟合洛伦兹函数；半极大值处的全宽度为22.3°，这意味着微棒在涂层内很好地对齐。
从图7所示的紫外/可见光谱(本测试所用仪器为UV/Vis spectrometer Cary 300)可以发现，在400-800纳米范围内，相比未涂层涤纶织物(PET fabric)，涂层织物(Coated fabric)的反射率增加了20％。
为了获得太阳热屏蔽能力的重复性结果，开展了室内太阳热屏蔽试验。采用AM1.5G辐照的太阳模拟器作为光源；塑料盒用于防止空气对流引起的温度波动。将黑色泡沫置于塑料箱底，吸收无遮挡的太阳光，使黑色泡沫的温度成为织物遮阳能力的一个指标。织物样品被放置在塑料盒的上方以遮挡太阳光。四个热电偶被送进箱内并与底部接触以测量套管内的温度。并且，以原涤纶机织物(T-PET)、硅橡胶涂层织物(原织物上涂覆了一层前述的粘结剂PDMS而没有其他添加)和玻璃片(厚度3mm的石英玻璃)作为对比。
如图8所示，在1h照射后，涂覆微棒涤纶织物(T-ZM)、原涤纶织物(T-PET)、硅橡胶涂层涤纶织物(T-PDMS)和玻璃片(Glass)的地温分别为54.9℃、64.8℃、64.7℃和107.8℃。涂敷氧化锌微棒的PET织物的地温比PET织物、硅橡胶包覆的PET织物低10℃，比玻璃片低53℃。
实施例3
将直径为0.5微米、长度为80微米的钛酸钾微棒(纯度99.5％，品牌：锆锡纳米公司)置于真空烘箱中，在100℃干燥1h，去除水分。然后研磨，用孔径为40微米的筛子分散。将0～9g过筛的钛酸钾微棒经强力搅拌，混入7mL硅油(陶氏康宁，室温粘度为25cST)中；用超声波分散器将该混合物分散，形成稳定的颜料糊。
将
Figure PCTCN2019084074-appb-000015
6200A和
Figure PCTCN2019084074-appb-000016
LR 6200B，按同等比例配制成二甲基聚硅氧烷粘结剂。然后将上述颜料糊与10克二甲基聚硅氧烷粘结剂混合，使颜料糊与二甲基聚硅氧烷粘结剂(
Figure PCTCN2019084074-appb-000017
6200A和
Figure PCTCN2019084074-appb-000018
6200B两者的混合物)的质量比为7：10。将混合得到的涂层剂最终在真空中放置1小时，在室温下去除所捕获的气泡。所制备的涂布剂存放于室温下，可 在使用前贮存5天。
将制备的涂布剂放置在厚度为0.3mm的聚丙烯机织物上，在该织物上以丝径0.01mm的梅耶棒，速度为3m/min进行涂布。涂布后的织物在100℃下固化10min。热固化后的涂覆织物用洗衣机清洗，去除未附着的微棒。清洗后的织物在100℃的干燥空气中干燥2-10分钟，得到干燥的涂层织物。
在压缩力为6g时，涂层织物的平均厚度为0.4mm，标准差为0.02mm，而未涂覆织物的厚度为0.3mm，则涂层厚度为0.1mm。
按照实施例2中的方法，原装聚丙烯织物(pp0)和分别涂覆0g、2.25g、4.5g和9g微棒的丙纶织物(简写为pp+pdms、pp2.25、pp4.5、pp9)，1h照射后地温分别为65℃、60℃、55℃、45℃和42℃，如图9所示。
实施例4
将直径为1微米、长度为40微米的ZnO微棒(实施例1制得)置于真空烘箱中，在100℃下干燥1h，去除水分。然后研磨，用孔径为40微米的筛子分散。将0～9g过筛的氧化锌微棒通过强力搅拌，混入7mL硅油(陶氏康宁，室温粘度为25cST)中；用超声波分散器将该混合物分散，形成稳定的颜料糊。
将
Figure PCTCN2019084074-appb-000019
6200A和
Figure PCTCN2019084074-appb-000020
LR 6200B，按同等比例配制成二甲基聚硅氧烷粘结剂。然后将上述颜料糊与10g二甲基聚硅氧烷粘结剂混合，使颜料糊与二甲基聚硅氧烷粘结剂(
Figure PCTCN2019084074-appb-000021
6200A和
Figure PCTCN2019084074-appb-000022
6200B两者的混合物)的质量比为7：10。将混合得到的涂层剂最终在真空中放置1小时，在室温下去除所捕获的气泡。所制备的涂布剂存放于室温下，可在使用前贮存5天。
将制备的涂布剂放置在厚度为0.5mm的涤纶机织物上，在该织物上以丝径0.01mm的梅耶棒，速度为3m/min进行涂布。涂布后的织物在100℃下固化10min。热固化后的涂层织物用洗衣机清洗，去除未附着的氧化锌微棒。清洗后的织物在100℃的干燥空气中干燥2-10分钟，得到干燥的涂层织物。
在压缩力为6g时，涂层织物的平均厚度为0.6mm，标准差为0.02mm，而未涂覆织物的厚度为0.5mm，则涂层厚度为0.1mm。
原装PET织物和分别涂敷2.25g、4.5g和9g微棒的涤纶织物(简写为PZ2.25、PZ4.5、PZ9)，1h照射后地温分别为65℃、60℃、56℃和52℃， 如图10所示。
实施例5
将实施例2中的涂层织物进行以下性能测试：
1.该样品的防水性通过AATCC试验方法35-2006(耐水性：雨水试验)进行了测试。为了模拟暴雨的情况，在3英尺的水压下进行了5分钟的试验。结果表明，涂层织物透水量小于0.2g。这表明，本申请涂层织物的防水性明显优于美国海关的雨衣标准(在2英尺的水压下传输2分钟，透水量<1.0g)。
2.该样品的耐清洗性通过AATCC 61-2006进行了测试；对洗涤后织物样品的颜色变化进行了灰色评价(AATCC EP1-2012)；采用紫外-可见-近红外分光度法对洗涤织物样品的光学性能进行了评价；利用Leica立体显微镜对洗涤后织物的微观形貌进行了评价。
图11显示了12个加速清洗过程前后样品的照片，顶部为加速清洗前的样品，底部为加速清洗后的样品。结果表明，加速清洗12次后，外观无明显变化。表1显示了颜色变化的灰度值，12次加速清洗后的样品得到了5级的等级。
表1加速洗涤试验后涂覆微棒PET织物颜色变化的灰色标度
Figure PCTCN2019084074-appb-000023
此外，如图12所示，经过12次加速清洗后，透光率增加不到5％。这意味着清洗过程对透光率没有明显的影响。结果表明，本发明涂覆织物样品具有 很高的耐清洗性，能经受12次快速清洗，达到了可交付的要求。
3.通过ASTM G 155测量样品的抗阳光照射能力。试验持续时间为1440h，即55-56天的模拟阳光照射；对照射后涂层织物样品的颜色变化进行了灰色评价(AATCC EP1-2012)；采用紫外-可见-近红外分光度法对照射后涂层织物样品的光学性能进行了评价；利用Leica立体显微镜对裸露织物的微观形貌进行了评价。
图13显示了1440小时后涂覆微棒的PET织物的照片，顶部为日光风化0小时的样品，底部为日光风化1440小时的样品。结果表明，1440h照射试验后无明显变化。表2显示了颜色变化的灰度值，经过1440h的日照风化试验，样品得到了5分的等级。
表2微棒涂层PET织物日晒老化后颜色变化的灰色标度
Figure PCTCN2019084074-appb-000024
在阳光照射试验后，涂覆微棒的PET织物的UV/VIS光谱如图14所示。经过1440h的测试，照射后涂层样品的光谱与风化试验前的织物相似。同时，其在可见光和近红外波段的透过率在太阳光风化试验后有所下降，说明紫外线照射提高了其太阳反射率。两者都不发生紫外线降解。结果表明，本发明涂层织物样品具有很高的抗紫外线老化能力，能够承受55-56次连续的日光风化，达到了可交付的要求。
4.利用Martindale检测仪对涂层织物的耐磨性进行了测试；对被测织物样品的颜色变化进行了灰色评价(AATCC EP1-2012)。
图15为涂层涤纶织物在不同磨损后的照片，左边为磨损0次的样品，中间为10000次磨损后的样品，右边为30000次磨损后的样品。结果表明，在10000次磨损循环后，只有部分涂层被去除。经过30000次磨损循环后，表面涂层被去除，但纱线之间的涂层仍然存在。并且，没有观察到织物起毛起球以及损坏现象。根据颜色变化的灰度值，30k循环后的值为3-4，表明本发明中涂层具有很高的耐磨性。
由以上实施例可知，本发明实施例提供的太阳能隔热织物中，织物基底上复合的氧化锌微棒阵列沿涂层方向水平排列，可模拟撒哈拉银蚁的微毛结构(SSAnt)；这些反光微米棒不仅可以有效地反射太阳热量而不牺牲聚酯等织物的半透明性，而且提高了热发射率。本发明实施例中经处理后的织物可以遮挡太阳热量，降低该织物下方区域的温度。本发明该技术可提高织物屋顶的太阳能屏蔽能力，使其成为低成本的凉爽屋顶。这不仅提高了热舒适性，而且降低了空调的费用。同时，可以最大限度地减小城市热岛效应。
以上所述仅是本发明的优选实施方式，应当指出，对于使本技术领域的专业技术人员，在不脱离本发明技术原理的前提下，是能够实现对这些实施例的多种修改的，而这些修改也应视为本发明应该保护的范围。

Claims (10)

  1. 一种屏蔽太阳能的热管理织物，包括：
    织物基底；
    复合在所述织物基底表面的含若干反光微米棒的涂层，所述涂层中反光微米棒呈沿涂层方向水平排列的阵列；所述反光微米棒为氧化锌微棒和钛酸钾微棒中的一种或多种。
  2. 根据权利要求1所述的屏蔽太阳能的热管理织物，其特征在于，所述织物基底为机织织物或非织造布。
  3. 根据权利要求1所述的屏蔽太阳能的热管理织物，其特征在于，所述织物基底的材质为聚酯、尼龙、纤维素纤维、聚丙烯和玻璃纤维中的一种或多种。
  4. 根据权利要求1所述的屏蔽太阳能的热管理织物，其特征在于，所述反光微米棒的直径为0.5～2.6微米，长度为10～80微米。
  5. 根据权利要求1所述的屏蔽太阳能的热管理织物，其特征在于，所述涂层由含所述反光微米棒的涂饰剂在织物基底上涂布形成，所述涂饰剂包含粘结剂，所述粘结剂优选为液体硅橡胶。
  6. 一种屏蔽太阳能的热管理织物的制备方法，包括以下步骤：
    将含反光微米棒的涂饰剂通过刀片涂覆法在织物上涂布，使所述反光微米棒的阵列沿涂布方向水平排列在织物表面，经过热固化，得到屏蔽太阳能的热管理织物；所述反光微米棒为氧化锌微棒和钛酸钾微棒中的一种或多种。
  7. 根据权利要求6所述的制备方法，其特征在于，所述反光微米棒的直径为0.5～2.6微米，长度为10～80微米。
  8. 根据权利要求6所述的制备方法，其特征在于，所述涂饰剂包含粘结剂和稀释剂；所述粘结剂优选为液体硅橡胶，所述稀释剂优选为硅油。
  9. 根据权利要求6～8中任一项所述的制备方法，其特征在于，所述涂布的速度为1～10m/min。
  10. 如权利要求1～5中任一项所述的屏蔽太阳能的热管理织物，或权利要求6～9中任一项所述的制备方法得到的屏蔽太阳能的热管理织物，在制备建筑 材料中的应用。
PCT/CN2019/084074 2019-04-24 2019-04-24 一种屏蔽太阳能的热管理织物、其制备方法和应用 WO2020215245A1 (zh)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/CN2019/084074 WO2020215245A1 (zh) 2019-04-24 2019-04-24 一种屏蔽太阳能的热管理织物、其制备方法和应用

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/CN2019/084074 WO2020215245A1 (zh) 2019-04-24 2019-04-24 一种屏蔽太阳能的热管理织物、其制备方法和应用

Publications (1)

Publication Number Publication Date
WO2020215245A1 true WO2020215245A1 (zh) 2020-10-29

Family

ID=72940673

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2019/084074 WO2020215245A1 (zh) 2019-04-24 2019-04-24 一种屏蔽太阳能的热管理织物、其制备方法和应用

Country Status (1)

Country Link
WO (1) WO2020215245A1 (zh)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5401573A (en) * 1992-11-30 1995-03-28 Mcdonnell Douglas Corporation Protection of thermal control coatings from ultraviolet radiation
EP0980534A1 (fr) * 1998-03-03 2000-02-23 Saint-Gobain Vitrage Substrat transparent muni d'un empilement de couches reflechissant le rayonnement thermique
CN1289874A (zh) * 2000-09-29 2001-04-04 刘光恩 健康、凉爽的纺织品及其制备方法
CN104290395A (zh) * 2014-09-25 2015-01-21 北京航空航天大学 一种具有超疏水、防覆冰碳纤维板及其制备方法
CN105755843A (zh) * 2016-04-20 2016-07-13 江阴新嘉美服饰有限公司 一种耐晒防皱的气刀涂布式黄麻织物面料

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5401573A (en) * 1992-11-30 1995-03-28 Mcdonnell Douglas Corporation Protection of thermal control coatings from ultraviolet radiation
EP0980534A1 (fr) * 1998-03-03 2000-02-23 Saint-Gobain Vitrage Substrat transparent muni d'un empilement de couches reflechissant le rayonnement thermique
CN1289874A (zh) * 2000-09-29 2001-04-04 刘光恩 健康、凉爽的纺织品及其制备方法
CN104290395A (zh) * 2014-09-25 2015-01-21 北京航空航天大学 一种具有超疏水、防覆冰碳纤维板及其制备方法
CN105755843A (zh) * 2016-04-20 2016-07-13 江阴新嘉美服饰有限公司 一种耐晒防皱的气刀涂布式黄麻织物面料

Similar Documents

Publication Publication Date Title
TWI740202B (zh) 輻射致冷功能塗料及其製備方法與應用、選擇性輻射致冷塗層及複合材料
Chen et al. Cellulose-based hybrid structural material for radiative cooling
Li et al. All-Ceramic, compressible and scalable nanofibrous aerogels for subambient daytime radiative cooling
Zhang et al. Mechanically robust and spectrally selective convection shield for daytime subambient radiative cooling
JP6242902B2 (ja) 太陽エネルギーシステムに適した着色反射および高日射透過率を有する積層グレージング（ｌａｍｉｎａｔｅｄｇｌａｚｉｎｇ）
CN111690301B (zh) 具有梯度结构的辐射制冷涂层及其制备方法与应用
Kang et al. Keep cool: polyhedral ZnO@ ZIF-8 polymer coatings for daytime radiative cooling
CN107828289B (zh) 疏水自洁净表面温度昼夜低于气温的反思托克斯荧光及辐射制冷涂料及其制备方法
JP6944013B2 (ja) 放射冷却生地及び製品
Tsai et al. Scalable, flame-resistant, superhydrophobic ceramic metafibers for sustainable all-day radiative cooling
DE112020003642B4 (de) Infrarotselektive Strahlungskühlungs-Nanofunktions-Zusammensetzung und deren Herstellungsverfahren
CN116515219B (zh) 一种多孔辐射制冷薄膜及其制备方法
CN111827599B (zh) 一种降温发光多功能复合墙体涂层及其施工方法
Lin et al. Nanoparticle-polymer hybrid dual-layer coating with broadband solar reflection for high-performance daytime passive radiative cooling
CN102040878B (zh) 红外反射性骨料及其制备方法
WO2020215245A1 (zh) 一种屏蔽太阳能的热管理织物、其制备方法和应用
Li et al. A radiative cooling paper based on ceramic fiber for thermal management of human head
CN109913071A (zh) 一种温控复合节能材料
Li et al. Electrospun film composed of pearl-string-like microfibers exhibiting excellent radiative cooling performance, moisture permeability and self-cleaning function
Zhao et al. Structural porous ceramic for efficient daytime subambient radiative cooling
Xia et al. Water-based kaolin/polyacrylate cooling paint for exterior walls
Kang et al. Harnessing the synergy of ZrO2 and SiO2 dielectric micro-/nanoparticles in polymer-based photonic films for robust passive daytime radiative cooling
US20230383092A1 (en) Durability-enhanced thermochromic film and method of manufacturing same
CN114892417A (zh) 一种含有日间辐射制冷多孔涂层的纺织品及其制备方法、应用
KR20110059341A (ko) 적외선 차단 폴리카보네이트 복층판

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 19926438

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 19926438

Country of ref document: EP

Kind code of ref document: A1