A flame-retardant silk fabric and its preparation method

Abstract

The present invention relates to a flame-retardant silk fabric and a preparation method thereof. The feature is that the fabric can be prepared by the following method: First, a flame retardant is prepared by a polymerization reaction of vinyl-terminated dimethyl polysiloxane, 2,4,6-tribromostyrene and acrylic acid. Then, a finishing solution is prepared, and the silk fabric is finished in the finishing solution to obtain the flame-retardant silk fabric. The initial limiting oxygen index of the flame-retardant silk fabric prepared by the present invention reaches more than 29%, belonging to the range of flame-retardant materials; after 5 times of water washing, its limiting oxygen index does not decrease significantly and still reaches more than 26%.

Description

Technical Field

[0001] The present invention belongs to the technical field of fabric preparation, and particularly relates to a flame-retardant silk fabric and a preparation method thereof. Background Art

[0002] With the development of modern science and technology and the progress of the textile industry, the types of textiles are constantly increasing, and their application scope is continuously expanding and extending to all aspects of people's production and life. However, textile materials are generally flammable or combustible, which are likely to cause fire accidents. Therefore, the flame-retardant function of textiles is extremely important for eliminating fire hazards, delaying the spread of fire, and reducing the loss of people's lives and property.

[0003] Silk fabric is a fabric woven from natural protein fibers (real silk). Silk protein fibers have good biocompatibility with the human body, and many of its properties are also incomparable to other fibers, such as its soft and natural luster, unique silk chirping feeling, good health care, warmth retention and comfort. At present, silk products are mainly concentrated in pajamas, ties, interior decoration materials, etc. These products are relatively high-end products, so there are relatively high requirements for the flame-retardant performance of silk fibers.

[0004] The flame-retardant methods of silk fabrics can be mainly divided into three types: one is to improve the thermal stability of silk fabrics, that is, to increase the thermal cracking temperature, inhibit the generation of combustible gases, increase the degree of carbonization, so that silk fabrics are not easily ignited; the second is graft modification, that is, using radiation, high-energy electron beams or chemical initiators to make the real silk fabric undergo graft copolymerization with vinyl-type flame-retardant monomers, which is an effective and lasting flame-retardant modification method; the third is post-treatment grafting, which is to treat the real silk fiber with a solution containing an additive flame retardant (or metal ions) to make the flame retardant (or metal ions) penetrate into the interior of the real silk fiber to obtain flame retardancy.

[0005] Literature research shows that the flame retardant properties of silk fabrics have received extensive attention. Currently, the main method for preparing flame retardant silk fabrics is to soak the silk fabrics in a prepared flame retardant solution to endow the fabrics with high-efficiency flame retardant properties. For example, Chinese Patent Application No. 201210346262.4 discloses a method for preparing a silk flame retardant and flame retardant silk, which is prepared by the following method: submerging the silk fabric to be finished in a flame retardant solution, after heat treatment, taking out the silk fabric, washing with water and drying to obtain flame retardant silk. The flame retardant solution is obtained by reacting dimethyl chlorophosphate with a mixed solution containing alkanolamine, triethylamine and dichloromethane, wherein the alkanolamine is monoethanolamine or n-propanolamine. Although the above method for preparing flame retardant silk fabrics can achieve good flame retardant properties with a relatively small amount of additive due to the phosphorus-nitrogen synergistic effect in the molecule, however, the flame retardant used in this method is a chemical synthetic product, and some intermediates and solvents in the preparation process are toxic to the human body and will cause environmental pollution. Therefore, it is necessary to develop a new environmentally friendly, energy-saving and emission-reducing flame retardant silk fabric finishing technology to endow silk fabrics with excellent flame retardant properties. Summary of the Invention

[0006] Aiming at the above-mentioned drawbacks existing in the prior art, the purpose of the present invention is to provide a flame retardant silk fabric and a preparation method thereof.

[0007] The purpose of the present invention is to provide a flame retardant silk fabric, which can be prepared by the following method: First, a flame retardant is prepared by polymerizing vinyl-terminated dimethyl polysiloxane, 2,4,6-tribromostyrene and acrylic acid, and then a finishing solution is prepared, and the silk fabric is finished in the finishing solution to obtain the flame retardant silk fabric.

[0008] Another purpose of the present invention is to provide a preparation method of a flame retardant silk fabric, and the specific method includes the following steps:

[0009] (1) Preparation of the flame retardant: Dissolve vinyl-terminated dimethyl polysiloxane, 2,4,6-tribromostyrene and acrylic acid in chloroform to prepare a monomer solution, dissolve azobisisobutyronitrile in chloroform to prepare an initiator solution, and set aside; then under stirring conditions, control the temperature at 79-81°C, and simultaneously drop the prepared monomer solution and initiator solution into a four-necked flask filled with chloroform, and control the dropping time within 2-3 h. After the dropping is completed, keep warm for 3-4 h; finally, cool and carry out reduced pressure distillation to obtain the flame retardant.

[0010] Preferably, the dosage ratio of vinyl-terminated dimethyl polysiloxane (g), 2,4,6-tribromostyrene (g), acrylic acid (mL) and azobisisobutyronitrile (g) is: 1∶1-2∶5-7∶0.1-0.2.

[0011] (2) Preparation of flame-retardant silk fabric: Dissolve the flame retardant and sodium chloride obtained in step (1) in tap water, stir evenly to dissolve, and obtain a finishing solution; adjust the pH of the finishing solution to 5-6 with acetic acid, and at 90-100 °C, immerse the silk fabric in the finishing solution for 30-60 minutes. After immersion, rinse with tap water 3-5 times and dry to obtain the flame-retardant silk fabric.

[0012] Preferably, the dosage ratio of the silk fabric (g) to the finishing solution (mL) is: 1∶30-50.

[0013] Preferably, the dosage ratio of the flame retardant (g), sodium chloride (g) to tap water (mL) is: 1∶0.2-0.4∶100-200.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] (1) The present invention realizes grafting a compound containing silicone and bromine on the surface of the silk fabric, and this method significantly improves the flame retardancy of the silk fabric.

[0016] (2) The inventors of the present application unexpectedly found that the initial limiting oxygen index of the flame-retardant silk fabric prepared by the present invention reached more than 29%, belonging to the range of flame-retardant materials; after 5 times of washing with water, its limiting oxygen index did not decrease significantly and still reached more than 26%.

[0017] (3) The present invention prepared a compound containing silicone and bromine through a polymerization reaction and reacted it with the silk fabric through a chemical reaction; the compound containing silicone and bromine is an excellent flame retardant material, and thus the prepared silk fabric also has excellent flame retardancy.

[0018] (4) The inventors of the present application unexpectedly found that a chemical reaction between the compound containing silicone and bromine and the silk fabric can achieve a firm combination of the two; further discovery: after the silk fabric is washed with water many times, its flame retardancy is still not weakened.

[0019] (5) The flame-retardant silk fabric prepared by the method of the present invention has strong flame retardancy, the entire production process is simple, the price is low, and the production process has little environmental pollution. Specific Embodiments

[0020] Source of main raw materials: Vinyl-terminated dimethyl polysiloxane (molecular formula: C8H 18 OSi2) was purchased from Shanghai Macklin Biochemical Technology Co., Ltd.

[0021] The following examples and comparative examples illustrate the present invention in detail.

[0022] Example 1

[0023] A preparation method of a flame-retardant silk fabric in this embodiment, the preparation method comprises the following steps:

[0024] (1) Preparation of the flame retardant: Dissolve 1 g of vinyl-terminated dimethyl polysiloxane, 1.5 g of 2,4,6-tribromostyrene and 6 mL of acrylic acid in 100 mL of chloroform to prepare a monomer solution, and dissolve 0.15 g of azobisisobutyronitrile in 100 mL of chloroform to prepare an initiator solution for standby; then under stirring conditions, control the temperature at 80 °C, and simultaneously drop the prepared monomer solution and initiator solution into a four-necked flask containing 50 mL of chloroform respectively, and control the dropping time within 2.5 h. After the dropping is completed, keep warm for 3.5 h; finally cool down and carry out vacuum distillation to obtain the flame retardant.

[0025] (2) Preparation of the flame-retardant silk fabric: Dissolve 1 g of the flame retardant prepared in step (1) and 0.3 g of sodium chloride in 150 mL of tap water, stir evenly to dissolve, and prepare a finishing solution; adjust the pH of the finishing solution to 5.5 with acetic acid. At 95 °C, immerse the silk fabric in the finishing solution. The dosage ratio of the silk fabric (g) to the finishing solution (mL) is 1:40, and the immersion time is 45 minutes. After the immersion is completed, rinse with tap water 4 times and dry to obtain the flame-retardant silk fabric.

[0026] Example 2

[0027] A preparation method of a flame-retardant silk fabric in this embodiment, the preparation method comprises the following steps:

[0028] (1) Preparation of the flame retardant: Dissolve 1 g of vinyl-terminated dimethyl polysiloxane, 1 g of 2,4,6-tribromostyrene and 5 mL of acrylic acid in 100 mL of chloroform to prepare a monomer solution, and dissolve 0.1 g of azobisisobutyronitrile in 100 mL of chloroform to prepare an initiator solution for standby; then under stirring conditions, control the temperature at 79 °C, and simultaneously drop the prepared monomer solution and initiator solution into a four-necked flask containing 50 mL of chloroform respectively, and control the dropping time within 2 h. After the dropping is completed, keep warm for 3 h; finally cool down and carry out vacuum distillation to obtain the flame retardant.

[0029] (2) Preparation of the flame-retardant silk fabric: Dissolve 1 g of the flame retardant prepared in step (1) and 0.2 g of sodium chloride in 100 mL of tap water, stir evenly to dissolve, and prepare a finishing solution; adjust the pH of the finishing solution to 5 with acetic acid. At 90 °C, immerse the silk fabric in the finishing solution. The dosage ratio of the silk fabric (g) to the finishing solution (mL) is 1:30, and the immersion time is 30 minutes. After the immersion is completed, rinse with tap water 3 times and dry to obtain the flame-retardant silk fabric.

[0030] Example 3

[0031] A preparation method of a flame-retardant silk fabric according to this embodiment, the preparation method comprising the following steps:

[0032] (1) Preparation of the flame retardant: Dissolve 1 g of vinyl-terminated dimethyl polysiloxane, 2 g of 2,4,6-tribromostyrene and 7 mL of acrylic acid in 100 mL of chloroform to prepare a monomer solution, and dissolve 0.2 g of azobisisobutyronitrile in 100 mL of chloroform to prepare an initiator solution for standby; then under stirring conditions, control the temperature at 81 °C, and simultaneously drop the prepared monomer solution and initiator solution into a four-necked flask containing 50 mL of chloroform, control the dropping time at 3 h, after the dropping is completed, keep warm for 4 h; finally cool and carry out reduced pressure distillation to obtain the flame retardant.

[0033] (2) Preparation of the flame-retardant silk fabric: Dissolve 1 g of the flame retardant prepared in step (1) and 0.4 g of sodium chloride in 200 mL of tap water, stir evenly to dissolve, and prepare a finishing solution; adjust the pH of the finishing solution to 6 with acetic acid, and at 100 °C, immerse the silk fabric in the finishing solution, and the dosage ratio of the silk fabric (g) to the finishing solution (mL) is: 1:50, the immersion time is 60 minutes, after the immersion is completed, rinse with tap water 5 times and dry to obtain the flame-retardant silk fabric.

[0034] Comparative Example A

[0035] Taking Example 1 as a comparison, in this comparative example, reduce "0.15 g of azobisisobutyronitrile" in step (1) to "0.015 g of azobisisobutyronitrile", and implement other preparation methods according to the preparation method of Example 1.

[0036] Comparative Example B

[0037] Taking Example 1 as a comparison, in this comparative example, increase "0.15 g of azobisisobutyronitrile" in step (1) to "1.5 g of azobisisobutyronitrile", and implement other preparation methods according to the preparation method of Example 1.

[0038] Comparative Example C

[0039] Taking Example 1 as a comparison, in this comparative example, reduce "6 mL of acrylic acid" to "0.6 mL of acrylic acid" in step (1), and implement other preparation methods according to the preparation method of Example 1.

[0040] Comparative Example D

[0041] Taking Example 1 as a comparison, in this comparative example, increase "6 mL of acrylic acid" to "60 mL of acrylic acid" in step (1), and implement other preparation methods according to the preparation method of Example 1.

[0042] Comparative Example E

[0043] Taking Example 1 as a comparison, in this comparative example, in step (2), the dosage ratio of "the silk fabric (g) to the finishing solution (mL) is: 1∶40" is changed to "the dosage ratio of the silk fabric (g) to the finishing solution (mL) is: 1∶4", and other preparation methods are implemented according to the preparation method of Example 1.

[0044] Comparative Example F

[0045] Taking Example 1 as a comparison, in this comparative example, in step (2), the dosage ratio of "the silk fabric (g) to the finishing solution (mL) is: 1∶40" is changed to "the dosage ratio of the silk fabric (g) to the finishing solution (mL) is: 1∶400", and other preparation methods are implemented according to the preparation method of Example 1.

[0046] Performance evaluation example:

[0047] In order to better detect the flame retardancy of the silk fabric prepared in the present invention, the flame retardant properties of the silk fabrics prepared in the above specific Examples 1 to 3 and Comparative Examples A to F of the present invention and the purchased flame retardant silk fabric are tested. The test method adopts the oxygen index test method, that is, in accordance with GB / T 5454-1997 "Textiles - Burning performance - Oxygen index method", and the silk fabric is subjected to standard washing with reference to the washing method of the color fastness to washing tester in GB / T 20944.1-2007. The test results are shown in Table 1. The purchased flame retardant silk fabric was purchased from Xinxiang Zhuocheng Special Textiles Co., Ltd. Table 1 Flame retardant test results of the silk fabrics prepared in Examples 1 to 3 and Comparative Examples A to F and the purchased silk fabric before and after 5 times of washing

[0048]

[0049] The limiting oxygen index LOI is one of the important indicators of flame retardant materials. Generally, materials with a limiting oxygen index greater than 28% are classified as flame retardant materials. As can be seen from Table 1, the initial limiting oxygen index of the flame retardant silk fabric prepared in the present invention reaches more than 29%, belonging to the range of flame retardant materials; after 5 times of washing, its limiting oxygen index does not decrease significantly and still reaches more than 26%. During 5 times of washing, the flame retardant performance of the flame retardant silk fabric prepared in the present invention is slightly higher than that of the purchased flame retardant silk fabric. In addition, the limiting oxygen indices of the silk fabrics prepared in Comparative Examples A - F are all small, which indicates that the dosage of azobisisobutyronitrile, the dosage of acrylic acid, and the dosage ratio of the fabric to the diluent all have important effects on the flame retardant performance of the silk fabric. The flame retardant performance test shows that the flame retardant silk fabric prepared in the present invention has a good flame retardant effect and is a qualified flame retardant silk fabric.

Claims

1. A method for preparing a flame-retardant silk fabric, characterized in that, The preparation method is as follows: Dissolve the flame retardant and sodium chloride in tap water, stir evenly to dissolve them to obtain a finishing solution; adjust the pH of the finishing solution to 5 - 6 with acetic acid. At 90 - 100 °C, immerse the silk fabric in the finishing solution for 30 - 60 minutes. After immersion, rinse it with tap water 3 - 5 times and then dry it to obtain the flame-retardant silk fabric; wherein, the initial limiting oxygen index of the flame-retardant silk fabric is higher than 29%, and after 5 times of water washing, its limiting oxygen index is higher than 26%; the preparation method of the flame retardant is: dissolve vinyl-terminated dimethyl polysiloxane, 2,4,6-tribromostyrene and acrylic acid in chloroform to prepare a monomer solution, dissolve azobisisobutyronitrile in chloroform to prepare an initiator solution for standby; then under stirring conditions, control the temperature at 79 - 81 °C, and simultaneously drop the prepared monomer solution and initiator solution into a four-necked flask filled with chloroform respectively, and control the dropping time within 2 - 3 h. After dropping, keep the temperature for 3 - 4 h; finally, cool it and carry out vacuum distillation to obtain the flame retardant; The dosage ratio of the silk fabric to the finishing solution is: 1 g∶(30 - 50) mL; The dosage ratio of vinyl-terminated dimethyl polysiloxane, 2,4,6-tribromostyrene, acrylic acid and azobisisobutyronitrile is: 1 g∶(1 - 2) g∶(5 - 7) mL∶(0.1 - 0.2) g.

2. The preparation method of a flame-retardant silk fabric according to claim 1, characterized in that, The dosage ratio of the flame retardant, sodium chloride and tap water is: 1 g∶(0.2 - 0.4) g∶(100 - 200) mL.

3. A flame-retardant silk fabric, characterized in that, It is prepared by using the preparation method of a flame-retardant silk fabric according to any one of claims 1 - 2.

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