Flame retardant heat insulating polyester / cotton blended fabric and preparation method thereof

Abstract

The present invention belongs to the technical field of textile materials, and relates to a flame retardant and heat insulating polyester / cotton blended fabric and a preparation method thereof. Preparation method: After coating the polyester / cotton blended fabric with an aqueous polyurethane finishing liquid containing ammonium sulfate, pentaerythritol, expandable graphite and heat-expandable microspheres, the polyester / cotton blended fabric is pre-baked and baked in sequence to obtain the flame retardant and heat insulating polyester / cotton blended fabric, wherein the baking temperature is higher than the initial expansion temperature of the heat-expandable microspheres and not higher than the complete expansion temperature of the heat-expandable microspheres; the complete expansion temperature of the heat-expandable microspheres is not higher than the initial decomposition temperature of ammonium sulfate; the initial expansion temperature of the expandable graphite is 290-300°C; the flame retardant and heat insulating polyester / cotton blended fabric is composed of the polyester / cotton blended fabric and an aqueous polyurethane coating located on one or both sides of the fabric, wherein the aqueous polyurethane coating contains ammonium sulfate, pentaerythritol, expandable graphite and heat-expanded microspheres. The product prepared by the present invention has excellent flame retardant and heat insulating properties.

Description

Technical Field

[0001] The invention belongs to the technical field of textile materials and relates to a flame retardant and heat insulating polyester / cotton blended fabric and a preparation method thereof. Background Art

[0002] At present, people have higher and higher requirements for the thermal insulation performance of textiles. In order to improve the thermal insulation performance of textiles, the prior art usually introduces heat-expandable microspheres by coating the textiles. The heat-expandable microspheres are composed of a thermoplastic polymer shell and a low-boiling point liquid alkane gas wrapped therein. When the heat-expandable microspheres are heated, the liquid alkane gas in the ball vaporizes to generate internal pressure, and the thermoplastic shell begins to soften, showing a good expansion state. In addition, the volume of the heat-expandable microspheres after expansion remains stable and does not shrink after cooling, and the gas in the ball can make the expanded heat-expandable microspheres show a low thermal conductivity and excellent thermal insulation performance.

[0003] For example, patent application CN115785514A discloses a zinc oxide coated modified hollow heat-expandable microsphere and its preparation method and application. The patent uses ionic liquid and zinc acetate to treat the surface of the hollow heat-expandable microsphere, and then obtains the zinc oxide coated modified hollow heat-expandable microsphere after high-temperature heat treatment, and then mixes the zinc oxide coated modified hollow heat-expandable microsphere and water-based resin and other components to obtain a coating, and then forms a stable coating on the surface of the textile by coating, impregnation and other methods, giving the fabric heat insulation and ultraviolet protection capabilities. However, textiles are flammable items with poor flame retardant properties. During the combustion process of the textile treated with the coating, the liquid alkane gas in the hollow heat-expandable microsphere will accelerate the combustion of the textile, making the combustion of the textile more intense, and flame retardant modification is very difficult. Summary of the invention

[0004] The purpose of the present invention is to solve the problems existing in the prior art and to provide a flame retardant and heat insulating polyester / cotton blended fabric and a preparation method thereof.

[0005] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] A method for preparing a flame-retardant and heat-insulating polyester / cotton blended fabric comprises the following steps: coating the polyester / cotton blended fabric with an aqueous polyurethane finishing liquid containing ammonium sulfate, pentaerythritol, expandable graphite and heat-expandable microspheres, and then pre-baking and baking are performed in sequence to obtain the flame-retardant and heat-insulating polyester / cotton blended fabric, wherein the baking temperature is higher than the initial expansion temperature of the heat-expandable microspheres and not higher than the complete expansion temperature of the heat-expandable microspheres; the complete expansion temperature of the heat-expandable microspheres is not higher than the initial decomposition temperature of ammonium sulfate; and the initial expansion temperature of the expandable graphite is 290-300°C.

[0007] During the combustion of flame-retardant and heat-insulating polyester / cotton blended fabrics, since "the full expansion temperature of the heat-expandable microspheres is not higher than the initial decomposition temperature of ammonium sulfate", the heat-expandable microspheres are first damaged, releasing alkane gases, and then the ammonium sulfate decomposes (the decomposition temperature is generally lower than 250°C) to produce sulfuric acid. Sulfuric acid is a strong acid catalyst, which promotes the decomposition of pentaerythritol (the decomposition temperature is about 250°C), and pentaerythritol produces carbon residue. The combustion of alkane gases releases a large amount of carbon dioxide and water vapor, which causes the carbon residue produced by pentaerythritol to expand rapidly.

[0008] However, the carbon residue produced by pentaerythritol has poor stability and is easily decomposed and damaged at higher temperatures, thus losing its protective function. At the same time, the alkane gas continues to burn, and high molecular weight substances such as polyurethane, polyester, and cellulose also begin to thermally decompose and produce gas, making the carbon residue produced by pentaerythritol easily damaged and losing its protective function.

[0009] To solve this problem, the present invention adds expandable graphite with a high initial expansion temperature (initial expansion temperature is 290-300°C, expansion volume is ≥230ml / g) into the coating. The expandable graphite can instantly expand 150-300 times in volume when exposed to high temperature, changing from a sheet shape to a worm shape, so that the structure is loose, porous and curved, and the surface area is expanded. The expandable graphite used in the present invention starts to expand from about 300°C and fully expands until about 1000°C, thereby improving the thermal stability and strength of the residual carbon produced by pentaerythritol.

[0010] The present invention controls the baking temperature to be higher than the initial expansion temperature of the heat-expandable microspheres to ensure that the heat-expandable microspheres expand during the baking process, and controls the baking temperature to be no higher than the complete expansion temperature of the heat-expandable microspheres to avoid the heat-expandable microspheres from breaking during the baking process.

[0011] As the preferred technical solution:

[0012] In the preparation method of a flame retardant and heat insulating polyester / cotton blended fabric as described above, the heat-expandable microspheres are composed of a thermoplastic polymer shell (such as polyacrylic acid) and liquid alkane gas sealed therein; during the baking process, the liquid alkane gas vaporizes to generate pressure, and at the same time the thermoplastic polymer shell softens and expands, thereby making the flame retardant and heat insulating polyester / cotton blended fabric exhibit a lower thermal conductivity and excellent thermal insulation performance.

[0013] In the method for preparing a flame retardant and heat insulating polyester / cotton blended fabric as described above, the baking temperature is 110-130° C. and the baking time is 1-2 minutes.

[0014] In the method for preparing a flame retardant and heat insulating polyester / cotton blended fabric as described above, the pre-drying temperature is 70-90° C. and the time is 2-3 minutes.

[0015] In the method for preparing a flame-retardant and heat-insulating polyester / cotton blended fabric as described above, in the aqueous polyurethane finishing liquid, the content of ammonium sulfate is 8-10wt%, the content of pentaerythritol is 4-6wt%, the content of expandable graphite is 2-3wt%, and the content of thermally expandable microspheres is 10-15wt%.

[0016] The preparation method of the flame-retardant and heat-insulating polyester / cotton blended fabric as described above comprises the following steps of preparing the water-based polyurethane finishing liquid: adding ammonium sulfate, pentaerythritol, expandable graphite and heat-expandable microspheres into the water-based polyurethane, stirring and dispersing the mixture uniformly, and removing bubbles to obtain the water-based polyurethane finishing liquid.

[0017] In the method for preparing a flame-retardant and heat-insulating polyester / cotton blended fabric as described above, the stirring speed is 500-800 rpm and the time is 15-20 min; the defoaming is performed by standing or stirring at a low speed.

[0018] In the method for preparing a flame retardant and heat insulating polyester / cotton blended fabric as described above, the coating treatment is performed by an automatic coating machine; after the coating treatment, the weight gain of the polyester / cotton blended fabric is 80-200 g / m 2 The higher the weight gain, the better the thermal insulation performance of the coated polyester / cotton blended fabric, but too high a weight gain will result in a serious loss of the fabric's hand feel.

[0019] The present invention also provides a flame retardant and heat insulating polyester / cotton blended fabric prepared by the method for preparing a flame retardant and heat insulating polyester / cotton blended fabric as described in any of the above items, comprising a polyester / cotton blended fabric and an aqueous polyurethane coating located on one or both sides of the fabric, wherein the aqueous polyurethane coating contains ammonium sulfate, pentaerythritol, expandable graphite and thermally expanded microspheres.

[0020] As the preferred technical solution:

[0021] The flame retardant and heat insulating polyester / cotton blended fabric has a thermal conductivity of less than 0.07 W / m·K, a damage length of less than 10.9 cm, a carbon residue of more than 25%, and a heat release rate peak of less than 205 kW / m 2 .

[0022] Beneficial effects:

[0023] The invention adopts heat-expandable microspheres to carry out coating modification on polyester / cotton blended fabrics, and the flame-retardant and heat-insulating polyester / cotton blended fabrics obtained have excellent heat-insulating properties;

[0024] The invention adopts ammonium sulfate, pentaerythritol and expandable graphite as flame retardants to improve the flame retardant properties of flame retardant heat insulating polyester / cotton blended fabrics. The preparation process is simple and is carried out simultaneously with the heat insulating coating. The prepared flame retardant heat insulating polyester / cotton blended fabric has good flame retardant properties and safety protection properties and has high practical application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a surface scanning electron microscope image of the polyester / cotton blended fabric of Comparative Example 1;

[0026] Figure 2 This is a surface scanning electron microscope image of the flame retardant and heat insulating polyester / cotton blended fabric of Example 1 of the present invention. DETAILED DESCRIPTION

[0027] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

[0028] The following are the test methods for the relevant performance indicators in each embodiment and comparative example:

[0029] Thermal conductivity: The thermal conductivity of the samples was tested using a Hot Disk TPS 2500S thermal conductivity tester in accordance with ISO 22007-2 standard.

[0030] Damage length: The flame retardant properties of the samples were tested and characterized using the M233M fabric vertical combustion tester in accordance with GB / T 5455-2014 standard.

[0031] Residual carbon content: The sample was calcined at 700°C in a LH-T-30 muffle furnace, and the residual carbon content of the sample after calcination was calculated.

[0032] Peak heat release rate: The peak heat release rate of the sample was tested and characterized using a VOUCH 6810 cone calorimeter in accordance with ISO 5660-1 standard.

[0033] Example 1

[0034] A method for preparing a flame retardant and heat insulating polyester / cotton blended fabric, the specific steps are as follows:

[0035] (1) Preparation of raw materials;

[0036] Ammonium sulfate;

[0037] Pentaerythritol;

[0038] Expandable graphite: The manufacturer is Shanghai Aladdin Biochemical Technology Co., Ltd., China, model number is E477901, and the initial expansion temperature is 290~300℃;

[0039] Thermal expansion microspheres: manufacturer is PLOYCHEM, USA, model 120DU15;

[0040] Waterborne polyurethane: manufacturer is Shanghai McLean Biochemical Technology Co., Ltd., China, model number is W909580, solid content is 45%;

[0041] Polyester / cotton blended fabric: The manufacturer is Shanghai Textile Industry Technical Supervision Institute, China. The polyester component is 80wt%, the cotton component is 20wt%, and the weight is 85.6g / m 2 ;

[0042] (2) adding ammonium sulfate, pentaerythritol, expandable graphite and heat-expandable microspheres into water-based polyurethane, stirring and dispersing them uniformly, and removing bubbles to obtain a water-based polyurethane finishing liquid containing ammonium sulfate, pentaerythritol, expandable graphite and heat-expandable microspheres; wherein the stirring speed is 600 rpm and the stirring time is 17 minutes;

[0043] The obtained aqueous polyurethane finishing liquid containing ammonium sulfate, pentaerythritol, expandable graphite and heat-expandable microspheres has an ammonium sulfate content of 9wt%, a pentaerythritol content of 5wt%, an expandable graphite content of 2.5wt%, and a heat-expandable microsphere content of 13wt%.

[0044] (3) A single-side surface of a polyester / cotton blended fabric was coated with an aqueous polyurethane finishing liquid containing ammonium sulfate, pentaerythritol, expandable graphite and heat-expandable microspheres (using an automatic coating machine); after the coating treatment, the weight gain of the polyester / cotton blended fabric was 90 g / m 2 ;

[0045] (4) Pre-baking and baking the coated polyester / cotton blended fabric in turn to obtain a flame retardant and heat insulating polyester / cotton blended fabric; wherein the pre-baking temperature is 80° C., the pre-baking time is 2.5 min, the baking temperature is 120° C., and the baking time is 1.5 min.

[0046] The surface scanning electron microscope image of the flame retardant and heat insulating polyester / cotton blended fabric is as follows: Figure 2 As shown in the figure, the flame retardant and heat insulating polyester / cotton blended fabric is composed of a polyester / cotton blended fabric and a water-based polyurethane coating on one side of the fabric, wherein the water-based polyurethane coating contains ammonium sulfate, pentaerythritol, expandable graphite and thermally expanded microspheres; the flame retardant and heat insulating polyester / cotton blended fabric has a thermal conductivity of 0.061 W / m·K, a damaged length of 10.1 cm, a carbon residue of 33%, and a peak heat release rate of 190 kW / m 2 .

[0047] Comparative Example 1

[0048] A method for preparing a polyester / cotton blended fabric is basically the same as that of Example 1, except that steps (2) to (3) are not performed and the polyester / cotton blended fabric in step (4) is not subjected to coating treatment.

[0049] The surface scanning electron microscope image of the final polyester / cotton blended fabric is as follows: Figure 1 As shown in the figure, the thermal conductivity of polyester / cotton blended fabric is 0.13W / m·K, the damage length is 30cm, the carbon residue is 5.0%, and the peak heat release rate is 350kW / m 2 .

[0050] By comparing Example 1 with Comparative Example 1, it can be seen that the coating treatment significantly improves the thermal insulation and flame retardant properties of the polyester / cotton blended fabric.

[0051] Comparative Example 2

[0052] A method for preparing a polyester / cotton blended fabric is basically the same as that of Example 1, except that ammonium sulfate, pentaerythritol and expandable graphite are not added in step (2).

[0053] The resulting polyester / cotton blended fabric burned violently during the test, with a damage length of 30 cm.

[0054] Compared with Example 1, the flame retardant properties of the polyester / cotton blended fabric in Comparative Example 2 are significantly reduced. This is because the polyester / cotton blended fabric in Comparative Example 2 contains a large amount of alkane gas, which makes it difficult to flame retard.

[0055] Comparative Example 3

[0056] A method for preparing a polyester / cotton blended fabric is basically the same as that of Example 1, except that expandable graphite is not added in step (2).

[0057] The final polyester / cotton blended fabric had a damage length of 16.9 cm, a carbon residue of 15.3%, and a peak heat release rate of 265 kW / m 2 .

[0058] Compared with Example 1, the flame retardant properties of the polyester / cotton blended fabric in Comparative Example 3 are significantly reduced. This is because the residual carbon subsequently generated in Comparative Example 3 is not very stable and is easily broken, resulting in poor flame retardant properties.

[0059] Comparative Example 4

[0060] A method for preparing a polyester / cotton blended fabric is basically the same as that in Example 1, except that the expandable graphite is replaced by non-expandable graphite (manufacturer: Shanghai Aladdin Biochemical Technology Co., Ltd., China, brand number G434783).

[0061] The final polyester / cotton blended fabric had a damage length of 16.4 cm, a carbon residue of 18.1%, and a peak heat release rate of 260 kW / m 2 .

[0062] Compared with Example 1, the flame retardant properties of the polyester / cotton blended fabric in Comparative Example 4 are significantly reduced. This is because the non-expandable graphite in Comparative Example 4 cannot expand like the expandable graphite, and thus cannot improve the thermal stability and strength of the residual carbon produced by pentaerythritol.

[0063] Example 2

[0064] A method for preparing a flame retardant and heat insulating polyester / cotton blended fabric, the specific steps are as follows:

[0065] (1) Preparation of raw materials;

[0066] Ammonium sulfate;

[0067] Pentaerythritol;

[0068] Expandable graphite: The manufacturer is Shanghai Aladdin Biochemical Technology Co., Ltd., China, model number is E477901, and the initial expansion temperature is 290~300℃;

[0069] Thermal expansion microspheres: manufacturer is PLOYCHEM, USA, model 120DU15;

[0070] Waterborne polyurethane: manufacturer is Shanghai McLean Biochemical Technology Co., Ltd., China, model number is W909580, solid content is 45%;

[0071] Polyester / cotton blended fabric: The manufacturer is Shanghai Textile Industry Technical Supervision Institute, China. The polyester component is 80wt%, the cotton component is 20wt%, and the weight is 85.6g / m 2 ;

[0072] (2) adding ammonium sulfate, pentaerythritol, expandable graphite and heat-expandable microspheres into water-based polyurethane, stirring and dispersing the mixture uniformly, and removing bubbles to obtain a water-based polyurethane finishing liquid containing ammonium sulfate, pentaerythritol, expandable graphite and heat-expandable microspheres; wherein the stirring speed is 550 rpm and the stirring time is 19 minutes;

[0073] The obtained aqueous polyurethane finishing liquid containing ammonium sulfate, pentaerythritol, expandable graphite and heat-expandable microspheres has an ammonium sulfate content of 8.5wt%, a pentaerythritol content of 4.5wt%, an expandable graphite content of 2.3wt%, and a heat-expandable microsphere content of 12wt%.

[0074] (3) A single-side surface of a polyester / cotton blended fabric was coated with an aqueous polyurethane finishing liquid containing ammonium sulfate, pentaerythritol, expandable graphite and heat-expandable microspheres (using an automatic coating machine); after the coating treatment, the weight gain of the polyester / cotton blended fabric was 85 g / m 2 ;

[0075] (4) Pre-baking and baking the coated polyester / cotton blended fabric in turn to obtain a flame retardant and heat insulating polyester / cotton blended fabric; wherein the pre-baking temperature is 75° C., the pre-baking time is 2.7 min, the baking temperature is 115° C., and the baking time is 1.8 min.

[0076] The flame retardant and heat-insulating polyester / cotton blended fabric finally prepared is composed of a polyester / cotton blended fabric and a water-based polyurethane coating on one side of the fabric, wherein the water-based polyurethane coating contains ammonium sulfate, pentaerythritol, expandable graphite and thermally expanded microspheres; the flame retardant and heat-insulating polyester / cotton blended fabric has a thermal conductivity of 0.065 W / m·K, a damaged length of 10.5 cm, a carbon residue of 29%, and a peak heat release rate of 197 kW / m 2 .

[0077] Example 3

[0078] A method for preparing a flame retardant and heat insulating polyester / cotton blended fabric, the specific steps are as follows:

[0079] (1) Preparation of raw materials;

[0080] Ammonium sulfate;

[0081] Pentaerythritol;

[0082] Expandable graphite: The manufacturer is Shanghai Aladdin Biochemical Technology Co., Ltd., China, model number is E477901, and the initial expansion temperature is 290~300℃;

[0083] Thermal expansion microspheres: manufacturer is PLOYCHEM, USA, model 120DU15;

[0084] Waterborne polyurethane: manufacturer is Shanghai McLean Biochemical Technology Co., Ltd., China, model number is W909580, solid content is 45%;

[0085] Polyester / cotton blended fabric: The manufacturer is Shanghai Textile Industry Technical Supervision Institute, China. The polyester component is 80wt%, the cotton component is 20wt%, and the weight is 85.6g / m 2 ;

[0086] (2) adding ammonium sulfate, pentaerythritol, expandable graphite and heat-expandable microspheres into water-based polyurethane, stirring and dispersing them uniformly, and removing bubbles to obtain a water-based polyurethane finishing liquid containing ammonium sulfate, pentaerythritol, expandable graphite and heat-expandable microspheres; wherein the stirring speed is 500 rpm and the stirring time is 20 min;

[0087] The obtained aqueous polyurethane finishing liquid containing ammonium sulfate, pentaerythritol, expandable graphite and heat-expandable microspheres has an ammonium sulfate content of 8wt%, a pentaerythritol content of 4wt%, an expandable graphite content of 2wt%, and a heat-expandable microsphere content of 10wt%.

[0088] (3) A single-side surface of a polyester / cotton blended fabric was coated with an aqueous polyurethane finishing liquid containing ammonium sulfate, pentaerythritol, expandable graphite and heat-expandable microspheres (using an automatic coating machine); after the coating treatment, the weight gain of the polyester / cotton blended fabric was 80 g / m 2 ;

[0089] (4) Pre-baking and baking the coated polyester / cotton blended fabric in turn to obtain a flame retardant and heat insulating polyester / cotton blended fabric; wherein the pre-baking temperature is 70° C., the pre-baking time is 3 min, the baking temperature is 110° C., and the baking time is 2 min.

[0090] The flame retardant and heat-insulating polyester / cotton blended fabric finally prepared is composed of a polyester / cotton blended fabric and a water-based polyurethane coating on one side of the fabric, wherein the water-based polyurethane coating contains ammonium sulfate, pentaerythritol, expandable graphite and thermally expanded microspheres; the flame retardant and heat-insulating polyester / cotton blended fabric has a thermal conductivity of 0.07 W / m·K, a damaged length of 10.9 cm, a carbon residue of 25%, and a peak heat release rate of 205 kW / m 2 .

[0091] Example 4

[0092] A method for preparing a flame retardant and heat insulating polyester / cotton blended fabric, the specific steps are as follows:

[0093] (1) Preparation of raw materials;

[0094] Ammonium sulfate;

[0095] Pentaerythritol;

[0096] Expandable graphite: The manufacturer is Shanghai Aladdin Biochemical Technology Co., Ltd., China, model number is E477901, and the initial expansion temperature is 290~300℃;

[0097] Thermal expansion microspheres: manufacturer is PLOYCHEM, USA, model 120DU15;

[0098] Waterborne polyurethane: manufacturer is Shanghai McLean Biochemical Technology Co., Ltd., China, model number is W909580, solid content is 45%;

[0099] Polyester / cotton blended fabric: The manufacturer is Shanghai Textile Industry Technical Supervision Institute, China. The polyester component is 80wt%, the cotton component is 20wt%, and the weight is 85.6g / m 2 ;

[0100] (2) adding ammonium sulfate, pentaerythritol, expandable graphite and heat-expandable microspheres into water-based polyurethane, stirring and dispersing them uniformly, and removing bubbles to obtain a water-based polyurethane finishing liquid containing ammonium sulfate, pentaerythritol, expandable graphite and heat-expandable microspheres; wherein the stirring speed is 700 rpm and the stirring time is 16 minutes;

[0101] The obtained aqueous polyurethane finishing liquid containing ammonium sulfate, pentaerythritol, expandable graphite and heat-expandable microspheres has an ammonium sulfate content of 9.5wt%, a pentaerythritol content of 5.5wt%, an expandable graphite content of 2.7wt%, and a heat-expandable microsphere content of 14wt%.

[0102] (3) A single-side surface of a polyester / cotton blended fabric was coated with an aqueous polyurethane finishing liquid containing ammonium sulfate, pentaerythritol, expandable graphite and heat-expandable microspheres (using an automatic coating machine); after the coating treatment, the weight gain of the polyester / cotton blended fabric was 95 g / m 2 ;

[0103] (4) Pre-baking and baking the coated polyester / cotton blended fabric in turn to obtain a flame retardant and heat insulating polyester / cotton blended fabric; wherein the pre-baking temperature is 85° C., the pre-baking time is 2.3 min, the baking temperature is 125° C., and the baking time is 1.3 min.

[0104] The flame retardant and heat-insulating polyester / cotton blended fabric finally prepared is composed of a polyester / cotton blended fabric and a water-based polyurethane coating on one side of the fabric, wherein the water-based polyurethane coating contains ammonium sulfate, pentaerythritol, expandable graphite and thermally expanded microspheres; the flame retardant and heat-insulating polyester / cotton blended fabric has a thermal conductivity of 0.06 W / m·K, a damaged length of 9.7 cm, a carbon residue of 35%, and a peak heat release rate of 185 kW / m 2 .

[0105] Example 5

[0106] A method for preparing a flame retardant and heat insulating polyester / cotton blended fabric, the specific steps are as follows:

[0107] (1) Preparation of raw materials;

[0108] Ammonium sulfate;

[0109] Pentaerythritol;

[0110] Expandable graphite: The manufacturer is Shanghai Aladdin Biochemical Technology Co., Ltd., China, model number is E477901, and the initial expansion temperature is 290~300℃;

[0111] Thermal expansion microspheres: manufacturer is PLOYCHEM, USA, model 120DU15;

[0112] Waterborne polyurethane: manufacturer is Shanghai McLean Biochemical Technology Co., Ltd., China, model number is W909580, solid content is 45%;

[0113] Polyester / cotton blended fabric: The manufacturer is Shanghai Textile Industry Technical Supervision Institute, China. The polyester component is 80wt%, the cotton component is 20wt%, and the weight is 85.6g / m 2 ;

[0114] (2) adding ammonium sulfate, pentaerythritol, expandable graphite and heat-expandable microspheres into water-based polyurethane, stirring and dispersing them uniformly, and removing bubbles to obtain a water-based polyurethane finishing liquid containing ammonium sulfate, pentaerythritol, expandable graphite and heat-expandable microspheres; wherein the stirring speed is 800 rpm and the stirring time is 15 minutes;

[0115] The obtained aqueous polyurethane finishing liquid containing ammonium sulfate, pentaerythritol, expandable graphite and heat-expandable microspheres has an ammonium sulfate content of 10wt%, a pentaerythritol content of 6wt%, an expandable graphite content of 3wt%, and a heat-expandable microsphere content of 15wt%.

[0116] (3) A single-side surface of a polyester / cotton blended fabric was coated with an aqueous polyurethane finishing liquid containing ammonium sulfate, pentaerythritol, expandable graphite and heat-expandable microspheres (using an automatic coating machine); after the coating treatment, the weight gain of the polyester / cotton blended fabric was 100 g / m 2 ;

[0117] (4) Pre-baking and baking the coated polyester / cotton blended fabric in turn to obtain a flame retardant and heat insulating polyester / cotton blended fabric; wherein the pre-baking temperature is 90° C., the pre-baking time is 2 min, the baking temperature is 130° C., and the baking time is 1 min.

[0118] The flame retardant and heat-insulating polyester / cotton blended fabric finally prepared is composed of a polyester / cotton blended fabric and a water-based polyurethane coating on one side of the fabric, wherein the water-based polyurethane coating contains ammonium sulfate, pentaerythritol, expandable graphite and thermally expanded microspheres; the flame retardant and heat-insulating polyester / cotton blended fabric has a thermal conductivity of 0.058 W / m·K, a damaged length of 9.5 cm, a residual carbon content of 38%, and a peak heat release rate of 181 kW / m 2 .

[0119] Example 6

[0120] A method for preparing a flame retardant and heat insulating polyester / cotton blended fabric is basically the same as that in Example 5, except that: in step (3), the double-side surfaces of the polyester / cotton blended fabric are subjected to coating treatment. After the coating treatment, the overall weight gain of the polyester / cotton blended fabric is 200 g / m 2 .

[0121] The flame retardant and heat-insulating polyester / cotton blended fabric finally prepared is composed of a polyester / cotton blended fabric and a water-based polyurethane coating on both sides thereof, wherein the water-based polyurethane coating contains ammonium sulfate, pentaerythritol, expandable graphite and thermally expanded microspheres; the flame retardant and heat-insulating polyester / cotton blended fabric has a thermal conductivity of 0.056 W / m·K, a damaged length of 9.4 cm, a carbon residue of 39%, and a peak heat release rate of 178 kW / m 2 .

Claims

1. A method for preparing a flame retardant and heat insulating polyester / cotton blended fabric, characterized in that: After coating a polyester / cotton blended fabric with an aqueous polyurethane finishing liquid containing ammonium sulfate, pentaerythritol, expandable graphite and heat-expandable microspheres, the fabric is pre-baked and baked in sequence to obtain a flame-retardant and heat-insulating polyester / cotton blended fabric, wherein the baking temperature is higher than the initial expansion temperature of the heat-expandable microspheres and not higher than the complete expansion temperature of the heat-expandable microspheres; the complete expansion temperature of the heat-expandable microspheres is not higher than the initial decomposition temperature of ammonium sulfate; the initial expansion temperature of the expandable graphite is 290-300°C; the thermal conductivity of the flame-retardant and heat-insulating polyester / cotton blended fabric is lower than 0.07W / m·K, the damaged length is lower than 10.9cm, the residual carbon content is higher than 25%, and the peak value of the heat release rate is lower than 205kW / m 2 .

2. The method for preparing a flame retardant and heat insulating polyester / cotton blended fabric according to claim 1, characterized in that: The heat-expandable microspheres are composed of a thermoplastic polymer shell and liquid alkane gas sealed therein.

3. The method for preparing a flame retardant and heat insulating polyester / cotton blended fabric according to claim 2, characterized in that: The baking temperature is 110~130℃ and the time is 1~2min.

4. The method for preparing a flame retardant and heat insulating polyester / cotton blended fabric according to claim 3, characterized in that: The pre-baking temperature is 70~90℃ and the time is 2~3min.

5. The method for preparing a flame retardant and heat insulating polyester / cotton blended fabric according to claim 1, characterized in that: In the waterborne polyurethane finishing liquid, the content of ammonium sulfate is 8-10wt%, the content of pentaerythritol is 4-6wt%, the content of expandable graphite is 2-3wt%, and the content of thermally expandable microspheres is 10-15wt%.

6. The method for preparing a flame retardant and heat insulating polyester / cotton blended fabric according to claim 1, characterized in that: The preparation process of the water-based polyurethane finishing liquid is as follows: adding ammonium sulfate, pentaerythritol, expandable graphite and heat-expandable microspheres into the water-based polyurethane, stirring and dispersing the mixture uniformly, and removing bubbles to obtain the water-based polyurethane finishing liquid.

7. The method for preparing a flame retardant and heat insulating polyester / cotton blended fabric according to claim 6, characterized in that: The stirring speed is 500~800rpm and the time is 15~20min.

8. The method for preparing a flame retardant and heat insulating polyester / cotton blended fabric according to claim 1, characterized in that: The coating process is carried out by an automatic coating machine; after coating, the weight gain of polyester / cotton blended fabric is 80~200g / m 2 .

9. A flame retardant and heat insulating polyester / cotton blended fabric prepared by the method for preparing a flame retardant and heat insulating polyester / cotton blended fabric according to any one of claims 1 to 8, characterized in that: The invention is composed of a polyester / cotton blended fabric and a water-based polyurethane coating on one or both sides of the fabric. The water-based polyurethane coating contains ammonium sulfate, pentaerythritol, expandable graphite and thermally expanded microspheres.

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